Add support for TEE based trusted keys where TEE provides the functionality to seal and unseal trusted keys using hardware unique key. Also, this is an alternative in case platform doesn't possess a TPM device.
This patch-set has been tested with OP-TEE based early TA which can be found here [1].
[1] https://github.com/OP-TEE/optee_os/pull/3838
Changes in v4: 1. Pushed independent TEE features separately: - Part of recent TEE PR: https://lkml.org/lkml/2020/5/4/1062 2. Updated trusted-encrypted doc with TEE as a new trust source. 3. Rebased onto latest tpmdd/master.
Changes in v3: 1. Update patch #2 to support registration of multiple kernel pages. 2. Incoporate dependency patch #4 in this patch-set: https://patchwork.kernel.org/patch/11091435/
Changes in v2: 1. Add reviewed-by tags for patch #1 and #2. 2. Incorporate comments from Jens for patch #3. 3. Switch to use generic trusted keys framework.
Sumit Garg (4): KEYS: trusted: Add generic trusted keys framework KEYS: trusted: Introduce TEE based Trusted Keys doc: trusted-encrypted: updates with TEE as a new trust source MAINTAINERS: Add entry for TEE based Trusted Keys
Documentation/security/keys/trusted-encrypted.rst | 203 ++++++++++--- MAINTAINERS | 8 + include/keys/trusted-type.h | 48 ++++ include/keys/trusted_tee.h | 66 +++++ include/keys/trusted_tpm.h | 15 - security/keys/Kconfig | 3 + security/keys/trusted-keys/Makefile | 2 + security/keys/trusted-keys/trusted_common.c | 336 ++++++++++++++++++++++ security/keys/trusted-keys/trusted_tee.c | 282 ++++++++++++++++++ security/keys/trusted-keys/trusted_tpm1.c | 335 ++++----------------- 10 files changed, 974 insertions(+), 324 deletions(-) create mode 100644 include/keys/trusted_tee.h create mode 100644 security/keys/trusted-keys/trusted_common.c create mode 100644 security/keys/trusted-keys/trusted_tee.c
Current trusted keys framework is tightly coupled to use TPM device as an underlying implementation which makes it difficult for implementations like Trusted Execution Environment (TEE) etc. to provide trusked keys support in case platform doesn't posses a TPM device.
So this patch tries to add generic trusted keys framework where underlying implemtations like TPM, TEE etc. could be easily plugged-in.
Suggested-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: Sumit Garg sumit.garg@linaro.org --- include/keys/trusted-type.h | 45 ++++ include/keys/trusted_tpm.h | 15 -- security/keys/trusted-keys/Makefile | 1 + security/keys/trusted-keys/trusted_common.c | 333 +++++++++++++++++++++++++++ security/keys/trusted-keys/trusted_tpm1.c | 335 +++++----------------------- 5 files changed, 437 insertions(+), 292 deletions(-) create mode 100644 security/keys/trusted-keys/trusted_common.c
diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h index a94c03a..5559010 100644 --- a/include/keys/trusted-type.h +++ b/include/keys/trusted-type.h @@ -40,6 +40,51 @@ struct trusted_key_options { uint32_t policyhandle; };
+struct trusted_key_ops { + /* + * flag to indicate if trusted key implementation supports migration + * or not. + */ + unsigned char migratable; + + /* trusted key init */ + int (*init)(void); + + /* seal a trusted key */ + int (*seal)(struct trusted_key_payload *p, char *datablob); + + /* unseal a trusted key */ + int (*unseal)(struct trusted_key_payload *p, char *datablob); + + /* get random trusted key */ + int (*get_random)(unsigned char *key, size_t key_len); + + /* trusted key cleanup */ + void (*cleanup)(void); +}; + extern struct key_type key_type_trusted; +#if defined(CONFIG_TCG_TPM) +extern struct trusted_key_ops tpm_trusted_key_ops; +#endif + +#define TRUSTED_DEBUG 0 + +#if TRUSTED_DEBUG +static inline void dump_payload(struct trusted_key_payload *p) +{ + pr_info("trusted_key: key_len %d\n", p->key_len); + print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE, + 16, 1, p->key, p->key_len, 0); + pr_info("trusted_key: bloblen %d\n", p->blob_len); + print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE, + 16, 1, p->blob, p->blob_len, 0); + pr_info("trusted_key: migratable %d\n", p->migratable); +} +#else +static inline void dump_payload(struct trusted_key_payload *p) +{ +} +#endif
#endif /* _KEYS_TRUSTED_TYPE_H */ diff --git a/include/keys/trusted_tpm.h b/include/keys/trusted_tpm.h index a56d8e1..5753231 100644 --- a/include/keys/trusted_tpm.h +++ b/include/keys/trusted_tpm.h @@ -60,17 +60,6 @@ static inline void dump_options(struct trusted_key_options *o) 16, 1, o->pcrinfo, o->pcrinfo_len, 0); }
-static inline void dump_payload(struct trusted_key_payload *p) -{ - pr_info("trusted_key: key_len %d\n", p->key_len); - print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE, - 16, 1, p->key, p->key_len, 0); - pr_info("trusted_key: bloblen %d\n", p->blob_len); - print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE, - 16, 1, p->blob, p->blob_len, 0); - pr_info("trusted_key: migratable %d\n", p->migratable); -} - static inline void dump_sess(struct osapsess *s) { print_hex_dump(KERN_INFO, "trusted-key: handle ", DUMP_PREFIX_NONE, @@ -96,10 +85,6 @@ static inline void dump_options(struct trusted_key_options *o) { }
-static inline void dump_payload(struct trusted_key_payload *p) -{ -} - static inline void dump_sess(struct osapsess *s) { } diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile index 7b73ceb..2b1085b 100644 --- a/security/keys/trusted-keys/Makefile +++ b/security/keys/trusted-keys/Makefile @@ -4,5 +4,6 @@ #
obj-$(CONFIG_TRUSTED_KEYS) += trusted.o +trusted-y += trusted_common.o trusted-y += trusted_tpm1.o trusted-y += trusted_tpm2.o diff --git a/security/keys/trusted-keys/trusted_common.c b/security/keys/trusted-keys/trusted_common.c new file mode 100644 index 0000000..9bfd081 --- /dev/null +++ b/security/keys/trusted-keys/trusted_common.c @@ -0,0 +1,333 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2010 IBM Corporation + * Copyright (c) 2019, Linaro Limited + * + * Author: + * David Safford safford@us.ibm.com + * Added generic trusted key framework: Sumit Garg sumit.garg@linaro.org + * + * See Documentation/security/keys/trusted-encrypted.rst + */ + +#include <keys/user-type.h> +#include <keys/trusted-type.h> +#include <linux/capability.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/key-type.h> +#include <linux/module.h> +#include <linux/parser.h> +#include <linux/rcupdate.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/uaccess.h> + +static struct trusted_key_ops *available_tk_ops[] = { +#if defined(CONFIG_TCG_TPM) + &tpm_trusted_key_ops, +#endif +}; +static struct trusted_key_ops *tk_ops; + +enum { + Opt_err, + Opt_new, Opt_load, Opt_update, +}; + +static const match_table_t key_tokens = { + {Opt_new, "new"}, + {Opt_load, "load"}, + {Opt_update, "update"}, + {Opt_err, NULL} +}; + +/* + * datablob_parse - parse the keyctl data and fill in the + * payload structure + * + * On success returns 0, otherwise -EINVAL. + */ +static int datablob_parse(char *datablob, struct trusted_key_payload *p) +{ + substring_t args[MAX_OPT_ARGS]; + long keylen; + int ret = -EINVAL; + int key_cmd; + char *c; + + /* main command */ + c = strsep(&datablob, " \t"); + if (!c) + return -EINVAL; + key_cmd = match_token(c, key_tokens, args); + switch (key_cmd) { + case Opt_new: + /* first argument is key size */ + c = strsep(&datablob, " \t"); + if (!c) + return -EINVAL; + ret = kstrtol(c, 10, &keylen); + if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE) + return -EINVAL; + p->key_len = keylen; + ret = Opt_new; + break; + case Opt_load: + /* first argument is sealed blob */ + c = strsep(&datablob, " \t"); + if (!c) + return -EINVAL; + p->blob_len = strlen(c) / 2; + if (p->blob_len > MAX_BLOB_SIZE) + return -EINVAL; + ret = hex2bin(p->blob, c, p->blob_len); + if (ret < 0) + return -EINVAL; + ret = Opt_load; + break; + case Opt_update: + ret = Opt_update; + break; + case Opt_err: + return -EINVAL; + } + return ret; +} + +static struct trusted_key_payload *trusted_payload_alloc(struct key *key) +{ + struct trusted_key_payload *p = NULL; + int ret; + + ret = key_payload_reserve(key, sizeof(*p)); + if (ret < 0) + return p; + p = kzalloc(sizeof(*p), GFP_KERNEL); + + p->migratable = tk_ops->migratable; + + return p; +} + +/* + * trusted_instantiate - create a new trusted key + * + * Unseal an existing trusted blob or, for a new key, get a + * random key, then seal and create a trusted key-type key, + * adding it to the specified keyring. + * + * On success, return 0. Otherwise return errno. + */ +static int trusted_instantiate(struct key *key, + struct key_preparsed_payload *prep) +{ + struct trusted_key_payload *payload = NULL; + size_t datalen = prep->datalen; + char *datablob; + int ret = 0; + int key_cmd; + size_t key_len; + + if (datalen <= 0 || datalen > 32767 || !prep->data) + return -EINVAL; + + datablob = kmalloc(datalen + 1, GFP_KERNEL); + if (!datablob) + return -ENOMEM; + memcpy(datablob, prep->data, datalen); + datablob[datalen] = '\0'; + + payload = trusted_payload_alloc(key); + if (!payload) { + ret = -ENOMEM; + goto out; + } + + key_cmd = datablob_parse(datablob, payload); + if (key_cmd < 0) { + ret = key_cmd; + goto out; + } + + dump_payload(payload); + + switch (key_cmd) { + case Opt_load: + ret = tk_ops->unseal(payload, datablob); + dump_payload(payload); + if (ret < 0) + pr_info("trusted_key: key_unseal failed (%d)\n", ret); + break; + case Opt_new: + key_len = payload->key_len; + ret = tk_ops->get_random(payload->key, key_len); + if (ret != key_len) { + pr_info("trusted_key: key_create failed (%d)\n", ret); + goto out; + } + + ret = tk_ops->seal(payload, datablob); + if (ret < 0) + pr_info("trusted_key: key_seal failed (%d)\n", ret); + break; + default: + ret = -EINVAL; + } +out: + kzfree(datablob); + if (!ret) + rcu_assign_keypointer(key, payload); + else + kzfree(payload); + return ret; +} + +static void trusted_rcu_free(struct rcu_head *rcu) +{ + struct trusted_key_payload *p; + + p = container_of(rcu, struct trusted_key_payload, rcu); + kzfree(p); +} + +/* + * trusted_update - reseal an existing key with new PCR values + */ +static int trusted_update(struct key *key, struct key_preparsed_payload *prep) +{ + struct trusted_key_payload *p; + struct trusted_key_payload *new_p; + size_t datalen = prep->datalen; + char *datablob; + int ret = 0; + + if (key_is_negative(key)) + return -ENOKEY; + p = key->payload.data[0]; + if (!p->migratable) + return -EPERM; + if (datalen <= 0 || datalen > 32767 || !prep->data) + return -EINVAL; + + datablob = kmalloc(datalen + 1, GFP_KERNEL); + if (!datablob) + return -ENOMEM; + + new_p = trusted_payload_alloc(key); + if (!new_p) { + ret = -ENOMEM; + goto out; + } + + memcpy(datablob, prep->data, datalen); + datablob[datalen] = '\0'; + ret = datablob_parse(datablob, new_p); + if (ret != Opt_update) { + ret = -EINVAL; + kzfree(new_p); + goto out; + } + + /* copy old key values, and reseal with new pcrs */ + new_p->migratable = p->migratable; + new_p->key_len = p->key_len; + memcpy(new_p->key, p->key, p->key_len); + dump_payload(p); + dump_payload(new_p); + + ret = tk_ops->seal(new_p, datablob); + if (ret < 0) { + pr_info("trusted_key: key_seal failed (%d)\n", ret); + kzfree(new_p); + goto out; + } + + rcu_assign_keypointer(key, new_p); + call_rcu(&p->rcu, trusted_rcu_free); +out: + kzfree(datablob); + return ret; +} + +/* + * trusted_read - copy the sealed blob data to userspace in hex. + * On success, return to userspace the trusted key datablob size. + */ +static long trusted_read(const struct key *key, char *buffer, + size_t buflen) +{ + const struct trusted_key_payload *p; + char *bufp; + int i; + + p = dereference_key_locked(key); + if (!p) + return -EINVAL; + + if (buffer && buflen >= 2 * p->blob_len) { + bufp = buffer; + for (i = 0; i < p->blob_len; i++) + bufp = hex_byte_pack(bufp, p->blob[i]); + } + return 2 * p->blob_len; +} + +/* + * trusted_destroy - clear and free the key's payload + */ +static void trusted_destroy(struct key *key) +{ + kzfree(key->payload.data[0]); +} + +struct key_type key_type_trusted = { + .name = "trusted", + .instantiate = trusted_instantiate, + .update = trusted_update, + .destroy = trusted_destroy, + .describe = user_describe, + .read = trusted_read, +}; +EXPORT_SYMBOL_GPL(key_type_trusted); + +static int __init init_trusted(void) +{ + int i, ret = 0; + + for (i = 0; i < sizeof(available_tk_ops); i++) { + tk_ops = available_tk_ops[i]; + + if (!(tk_ops && tk_ops->init && tk_ops->seal && + tk_ops->unseal && tk_ops->get_random)) + continue; + + ret = tk_ops->init(); + if (ret) { + if (tk_ops->cleanup) + tk_ops->cleanup(); + } else { + break; + } + } + + /* + * encrypted_keys.ko depends on successful load of this module even if + * trusted key implementation is not found. + */ + if (ret == -ENODEV) + return 0; + + return ret; +} + +static void __exit cleanup_trusted(void) +{ + if (tk_ops->cleanup) + tk_ops->cleanup(); +} + +late_initcall(init_trusted); +module_exit(cleanup_trusted); + +MODULE_LICENSE("GPL"); diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c index 8001ab0..32fd1ea 100644 --- a/security/keys/trusted-keys/trusted_tpm1.c +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -1,29 +1,26 @@ // SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2010 IBM Corporation + * Copyright (c) 2019, Linaro Limited * * Author: * David Safford safford@us.ibm.com + * Switch to generic trusted key framework: Sumit Garg sumit.garg@linaro.org * * See Documentation/security/keys/trusted-encrypted.rst */
#include <crypto/hash_info.h> -#include <linux/uaccess.h> -#include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/parser.h> #include <linux/string.h> #include <linux/err.h> -#include <keys/user-type.h> #include <keys/trusted-type.h> #include <linux/key-type.h> -#include <linux/rcupdate.h> #include <linux/crypto.h> #include <crypto/hash.h> #include <crypto/sha.h> -#include <linux/capability.h> #include <linux/tpm.h> #include <linux/tpm_command.h>
@@ -703,7 +700,6 @@ static int key_unseal(struct trusted_key_payload *p,
enum { Opt_err, - Opt_new, Opt_load, Opt_update, Opt_keyhandle, Opt_keyauth, Opt_blobauth, Opt_pcrinfo, Opt_pcrlock, Opt_migratable, Opt_hash, @@ -712,9 +708,6 @@ enum { };
static const match_table_t key_tokens = { - {Opt_new, "new"}, - {Opt_load, "load"}, - {Opt_update, "update"}, {Opt_keyhandle, "keyhandle=%s"}, {Opt_keyauth, "keyauth=%s"}, {Opt_blobauth, "blobauth=%s"}, @@ -841,71 +834,6 @@ static int getoptions(char *c, struct trusted_key_payload *pay, return 0; }
-/* - * datablob_parse - parse the keyctl data and fill in the - * payload and options structures - * - * On success returns 0, otherwise -EINVAL. - */ -static int datablob_parse(char *datablob, struct trusted_key_payload *p, - struct trusted_key_options *o) -{ - substring_t args[MAX_OPT_ARGS]; - long keylen; - int ret = -EINVAL; - int key_cmd; - char *c; - - /* main command */ - c = strsep(&datablob, " \t"); - if (!c) - return -EINVAL; - key_cmd = match_token(c, key_tokens, args); - switch (key_cmd) { - case Opt_new: - /* first argument is key size */ - c = strsep(&datablob, " \t"); - if (!c) - return -EINVAL; - ret = kstrtol(c, 10, &keylen); - if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE) - return -EINVAL; - p->key_len = keylen; - ret = getoptions(datablob, p, o); - if (ret < 0) - return ret; - ret = Opt_new; - break; - case Opt_load: - /* first argument is sealed blob */ - c = strsep(&datablob, " \t"); - if (!c) - return -EINVAL; - p->blob_len = strlen(c) / 2; - if (p->blob_len > MAX_BLOB_SIZE) - return -EINVAL; - ret = hex2bin(p->blob, c, p->blob_len); - if (ret < 0) - return -EINVAL; - ret = getoptions(datablob, p, o); - if (ret < 0) - return ret; - ret = Opt_load; - break; - case Opt_update: - /* all arguments are options */ - ret = getoptions(datablob, p, o); - if (ret < 0) - return ret; - ret = Opt_update; - break; - case Opt_err: - return -EINVAL; - break; - } - return ret; -} - static struct trusted_key_options *trusted_options_alloc(void) { struct trusted_key_options *options; @@ -926,248 +854,99 @@ static struct trusted_key_options *trusted_options_alloc(void) return options; }
-static struct trusted_key_payload *trusted_payload_alloc(struct key *key) +static int tpm_tk_seal(struct trusted_key_payload *p, char *datablob) { - struct trusted_key_payload *p = NULL; - int ret; - - ret = key_payload_reserve(key, sizeof *p); - if (ret < 0) - return p; - p = kzalloc(sizeof *p, GFP_KERNEL); - if (p) - p->migratable = 1; /* migratable by default */ - return p; -} - -/* - * trusted_instantiate - create a new trusted key - * - * Unseal an existing trusted blob or, for a new key, get a - * random key, then seal and create a trusted key-type key, - * adding it to the specified keyring. - * - * On success, return 0. Otherwise return errno. - */ -static int trusted_instantiate(struct key *key, - struct key_preparsed_payload *prep) -{ - struct trusted_key_payload *payload = NULL; struct trusted_key_options *options = NULL; - size_t datalen = prep->datalen; - char *datablob; int ret = 0; - int key_cmd; - size_t key_len; int tpm2;
tpm2 = tpm_is_tpm2(chip); if (tpm2 < 0) return tpm2;
- if (datalen <= 0 || datalen > 32767 || !prep->data) - return -EINVAL; - - datablob = kmalloc(datalen + 1, GFP_KERNEL); - if (!datablob) - return -ENOMEM; - memcpy(datablob, prep->data, datalen); - datablob[datalen] = '\0'; - options = trusted_options_alloc(); - if (!options) { - ret = -ENOMEM; - goto out; - } - payload = trusted_payload_alloc(key); - if (!payload) { - ret = -ENOMEM; - goto out; - } + if (!options) + return -ENOMEM;
- key_cmd = datablob_parse(datablob, payload, options); - if (key_cmd < 0) { - ret = key_cmd; + ret = getoptions(datablob, p, options); + if (ret < 0) goto out; - } + dump_options(options);
if (!options->keyhandle) { ret = -EINVAL; goto out; }
- dump_payload(payload); - dump_options(options); + if (tpm2) + ret = tpm2_seal_trusted(chip, p, options); + else + ret = key_seal(p, options); + if (ret < 0) { + pr_info("tpm_trusted_key: key_seal failed (%d)\n", ret); + goto out; + }
- switch (key_cmd) { - case Opt_load: - if (tpm2) - ret = tpm2_unseal_trusted(chip, payload, options); - else - ret = key_unseal(payload, options); - dump_payload(payload); - dump_options(options); - if (ret < 0) - pr_info("trusted_key: key_unseal failed (%d)\n", ret); - break; - case Opt_new: - key_len = payload->key_len; - ret = tpm_get_random(chip, payload->key, key_len); - if (ret != key_len) { - pr_info("trusted_key: key_create failed (%d)\n", ret); + if (options->pcrlock) { + ret = pcrlock(options->pcrlock); + if (ret < 0) { + pr_info("tpm_trusted_key: pcrlock failed (%d)\n", ret); goto out; } - if (tpm2) - ret = tpm2_seal_trusted(chip, payload, options); - else - ret = key_seal(payload, options); - if (ret < 0) - pr_info("trusted_key: key_seal failed (%d)\n", ret); - break; - default: - ret = -EINVAL; - goto out; } - if (!ret && options->pcrlock) - ret = pcrlock(options->pcrlock); out: - kzfree(datablob); kzfree(options); - if (!ret) - rcu_assign_keypointer(key, payload); - else - kzfree(payload); return ret; }
-static void trusted_rcu_free(struct rcu_head *rcu) +static int tpm_tk_unseal(struct trusted_key_payload *p, char *datablob) { - struct trusted_key_payload *p; - - p = container_of(rcu, struct trusted_key_payload, rcu); - kzfree(p); -} - -/* - * trusted_update - reseal an existing key with new PCR values - */ -static int trusted_update(struct key *key, struct key_preparsed_payload *prep) -{ - struct trusted_key_payload *p; - struct trusted_key_payload *new_p; - struct trusted_key_options *new_o; - size_t datalen = prep->datalen; - char *datablob; + struct trusted_key_options *options = NULL; int ret = 0; + int tpm2;
- if (key_is_negative(key)) - return -ENOKEY; - p = key->payload.data[0]; - if (!p->migratable) - return -EPERM; - if (datalen <= 0 || datalen > 32767 || !prep->data) - return -EINVAL; + tpm2 = tpm_is_tpm2(chip); + if (tpm2 < 0) + return tpm2;
- datablob = kmalloc(datalen + 1, GFP_KERNEL); - if (!datablob) + options = trusted_options_alloc(); + if (!options) return -ENOMEM; - new_o = trusted_options_alloc(); - if (!new_o) { - ret = -ENOMEM; - goto out; - } - new_p = trusted_payload_alloc(key); - if (!new_p) { - ret = -ENOMEM; - goto out; - }
- memcpy(datablob, prep->data, datalen); - datablob[datalen] = '\0'; - ret = datablob_parse(datablob, new_p, new_o); - if (ret != Opt_update) { - ret = -EINVAL; - kzfree(new_p); + ret = getoptions(datablob, p, options); + if (ret < 0) goto out; - } + dump_options(options);
- if (!new_o->keyhandle) { + if (!options->keyhandle) { ret = -EINVAL; - kzfree(new_p); goto out; }
- /* copy old key values, and reseal with new pcrs */ - new_p->migratable = p->migratable; - new_p->key_len = p->key_len; - memcpy(new_p->key, p->key, p->key_len); - dump_payload(p); - dump_payload(new_p); + if (tpm2) + ret = tpm2_unseal_trusted(chip, p, options); + else + ret = key_unseal(p, options); + if (ret < 0) + pr_info("tpm_trusted_key: key_unseal failed (%d)\n", ret);
- ret = key_seal(new_p, new_o); - if (ret < 0) { - pr_info("trusted_key: key_seal failed (%d)\n", ret); - kzfree(new_p); - goto out; - } - if (new_o->pcrlock) { - ret = pcrlock(new_o->pcrlock); + if (options->pcrlock) { + ret = pcrlock(options->pcrlock); if (ret < 0) { - pr_info("trusted_key: pcrlock failed (%d)\n", ret); - kzfree(new_p); + pr_info("tpm_trusted_key: pcrlock failed (%d)\n", ret); goto out; } } - rcu_assign_keypointer(key, new_p); - call_rcu(&p->rcu, trusted_rcu_free); out: - kzfree(datablob); - kzfree(new_o); + kzfree(options); return ret; }
-/* - * trusted_read - copy the sealed blob data to userspace in hex. - * On success, return to userspace the trusted key datablob size. - */ -static long trusted_read(const struct key *key, char *buffer, - size_t buflen) -{ - const struct trusted_key_payload *p; - char *bufp; - int i; - - p = dereference_key_locked(key); - if (!p) - return -EINVAL; - - if (buffer && buflen >= 2 * p->blob_len) { - bufp = buffer; - for (i = 0; i < p->blob_len; i++) - bufp = hex_byte_pack(bufp, p->blob[i]); - } - return 2 * p->blob_len; -} - -/* - * trusted_destroy - clear and free the key's payload - */ -static void trusted_destroy(struct key *key) +int tpm_tk_get_random(unsigned char *key, size_t key_len) { - kzfree(key->payload.data[0]); + return tpm_get_random(chip, key, key_len); }
-struct key_type key_type_trusted = { - .name = "trusted", - .instantiate = trusted_instantiate, - .update = trusted_update, - .destroy = trusted_destroy, - .describe = user_describe, - .read = trusted_read, -}; - -EXPORT_SYMBOL_GPL(key_type_trusted); - static void trusted_shash_release(void) { if (hashalg) @@ -1182,14 +961,14 @@ static int __init trusted_shash_alloc(void)
hmacalg = crypto_alloc_shash(hmac_alg, 0, 0); if (IS_ERR(hmacalg)) { - pr_info("trusted_key: could not allocate crypto %s\n", + pr_info("tpm_trusted_key: could not allocate crypto %s\n", hmac_alg); return PTR_ERR(hmacalg); }
hashalg = crypto_alloc_shash(hash_alg, 0, 0); if (IS_ERR(hashalg)) { - pr_info("trusted_key: could not allocate crypto %s\n", + pr_info("tpm_trusted_key: could not allocate crypto %s\n", hash_alg); ret = PTR_ERR(hashalg); goto hashalg_fail; @@ -1217,16 +996,13 @@ static int __init init_digests(void) return 0; }
-static int __init init_trusted(void) +static int __init init_tpm_trusted(void) { int ret;
- /* encrypted_keys.ko depends on successful load of this module even if - * TPM is not used. - */ chip = tpm_default_chip(); if (!chip) - return 0; + return -ENODEV;
ret = init_digests(); if (ret < 0) @@ -1247,7 +1023,7 @@ static int __init init_trusted(void) return ret; }
-static void __exit cleanup_trusted(void) +static void __exit cleanup_tpm_trusted(void) { if (chip) { put_device(&chip->dev); @@ -1257,7 +1033,12 @@ static void __exit cleanup_trusted(void) } }
-late_initcall(init_trusted); -module_exit(cleanup_trusted); - -MODULE_LICENSE("GPL"); +struct trusted_key_ops tpm_trusted_key_ops = { + .migratable = 1, /* migratable by default */ + .init = init_tpm_trusted, + .seal = tpm_tk_seal, + .unseal = tpm_tk_unseal, + .get_random = tpm_tk_get_random, + .cleanup = cleanup_tpm_trusted, +}; +EXPORT_SYMBOL_GPL(tpm_trusted_key_ops);
On Wed, 2020-05-06 at 15:10 +0530, Sumit Garg wrote:
Current trusted keys framework is tightly coupled to use TPM device as an underlying implementation which makes it difficult for implementations like Trusted Execution Environment (TEE) etc. to provide trusked keys support in case platform doesn't posses a TPM device.
So this patch tries to add generic trusted keys framework where underlying implemtations like TPM, TEE etc. could be easily plugged-in.
Suggested-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: Sumit Garg sumit.garg@linaro.org
I tend to agree how this is implemented and could merge it as such.
I'm just thinking if we could refine this patch in a way that instead of copying TRUSTED_DEBUG macro we could just replace pr_info() statements with pr_debug()?
/Jarkko
On Thu, 14 May 2020 at 05:55, Jarkko Sakkinen jarkko.sakkinen@linux.intel.com wrote:
On Wed, 2020-05-06 at 15:10 +0530, Sumit Garg wrote:
Current trusted keys framework is tightly coupled to use TPM device as an underlying implementation which makes it difficult for implementations like Trusted Execution Environment (TEE) etc. to provide trusked keys support in case platform doesn't posses a TPM device.
So this patch tries to add generic trusted keys framework where underlying implemtations like TPM, TEE etc. could be easily plugged-in.
Suggested-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: Sumit Garg sumit.garg@linaro.org
I tend to agree how this is implemented and could merge it as such.
I'm just thinking if we could refine this patch in a way that instead of copying TRUSTED_DEBUG macro we could just replace pr_info() statements with pr_debug()?
AFAIU, TRUSTED_DEBUG being a security sensitive operation is only meant to be used in development environments and should be strictly disabled in production environments. But it may not always be true with pr_debug() with CONFIG_DYNAMIC_DEBUG=y which allows the debug paths to be compiled into the kernel which can be enabled/disabled at runtime.
IMO we should keep this TRUSTED_DEBUG macro, so that users are aware of its security sensitive nature and need to explicitly enable it to debug.
-Sumit
/Jarkko
On Thu, 2020-05-14 at 16:53 +0530, Sumit Garg wrote:
On Thu, 14 May 2020 at 05:55, Jarkko Sakkinen jarkko.sakkinen@linux.intel.com wrote:
On Wed, 2020-05-06 at 15:10 +0530, Sumit Garg wrote:
Current trusted keys framework is tightly coupled to use TPM device as an underlying implementation which makes it difficult for implementations like Trusted Execution Environment (TEE) etc. to provide trusked keys support in case platform doesn't posses a TPM device.
So this patch tries to add generic trusted keys framework where underlying implemtations like TPM, TEE etc. could be easily plugged-in.
Suggested-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: Sumit Garg sumit.garg@linaro.org
I tend to agree how this is implemented and could merge it as such.
I'm just thinking if we could refine this patch in a way that instead of copying TRUSTED_DEBUG macro we could just replace pr_info() statements with pr_debug()?
AFAIU, TRUSTED_DEBUG being a security sensitive operation is only meant to be used in development environments and should be strictly disabled in production environments. But it may not always be true with pr_debug() with CONFIG_DYNAMIC_DEBUG=y which allows the debug paths to be compiled into the kernel which can be enabled/disabled at runtime.
IMO we should keep this TRUSTED_DEBUG macro, so that users are aware of its security sensitive nature and need to explicitly enable it to debug.
You are absolutely correct.
/Jarkko
On Wed, May 06, 2020 at 03:10:14PM +0530, Sumit Garg wrote:
Current trusted keys framework is tightly coupled to use TPM device as an underlying implementation which makes it difficult for implementations like Trusted Execution Environment (TEE) etc. to provide trusked keys support in case platform doesn't posses a TPM device.
So this patch tries to add generic trusted keys framework where underlying implemtations like TPM, TEE etc. could be easily plugged-in.
Suggested-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: Sumit Garg sumit.garg@linaro.org
include/keys/trusted-type.h | 45 ++++ include/keys/trusted_tpm.h | 15 -- security/keys/trusted-keys/Makefile | 1 + security/keys/trusted-keys/trusted_common.c | 333 +++++++++++++++++++++++++++
I think trusted_core.c would be a better name (less ambiguous).
security/keys/trusted-keys/trusted_tpm1.c | 335 +++++----------------------- 5 files changed, 437 insertions(+), 292 deletions(-) create mode 100644 security/keys/trusted-keys/trusted_common.c
diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h index a94c03a..5559010 100644 --- a/include/keys/trusted-type.h +++ b/include/keys/trusted-type.h @@ -40,6 +40,51 @@ struct trusted_key_options { uint32_t policyhandle; }; +struct trusted_key_ops {
- /*
* flag to indicate if trusted key implementation supports migration* or not.*/- unsigned char migratable;
- /* trusted key init */
- int (*init)(void);
/* Init a key. */
- /* seal a trusted key */
- int (*seal)(struct trusted_key_payload *p, char *datablob);
/* Seal a key. */
- /* unseal a trusted key */
- int (*unseal)(struct trusted_key_payload *p, char *datablob);
/* Unseal a key. */
- /* get random trusted key */
- int (*get_random)(unsigned char *key, size_t key_len);
/* Get a randomized key. */
- /* trusted key cleanup */
- void (*cleanup)(void);
Please remove this from this commit since it is not in use in the scope of this commit. You should instead make a separate commit just for this callback, which explains what it is and how it will be used in the follow up commits.
+};
extern struct key_type key_type_trusted; +#if defined(CONFIG_TCG_TPM) +extern struct trusted_key_ops tpm_trusted_key_ops; +#endif
+#define TRUSTED_DEBUG 0
+#if TRUSTED_DEBUG +static inline void dump_payload(struct trusted_key_payload *p) +{
- pr_info("trusted_key: key_len %d\n", p->key_len);
- print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE,
16, 1, p->key, p->key_len, 0);- pr_info("trusted_key: bloblen %d\n", p->blob_len);
- print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE,
16, 1, p->blob, p->blob_len, 0);- pr_info("trusted_key: migratable %d\n", p->migratable);
+} +#else +static inline void dump_payload(struct trusted_key_payload *p) +{ +} +#endif #endif /* _KEYS_TRUSTED_TYPE_H */ diff --git a/include/keys/trusted_tpm.h b/include/keys/trusted_tpm.h index a56d8e1..5753231 100644 --- a/include/keys/trusted_tpm.h +++ b/include/keys/trusted_tpm.h @@ -60,17 +60,6 @@ static inline void dump_options(struct trusted_key_options *o) 16, 1, o->pcrinfo, o->pcrinfo_len, 0); } -static inline void dump_payload(struct trusted_key_payload *p) -{
- pr_info("trusted_key: key_len %d\n", p->key_len);
- print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE,
16, 1, p->key, p->key_len, 0);- pr_info("trusted_key: bloblen %d\n", p->blob_len);
- print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE,
16, 1, p->blob, p->blob_len, 0);- pr_info("trusted_key: migratable %d\n", p->migratable);
-}
static inline void dump_sess(struct osapsess *s) { print_hex_dump(KERN_INFO, "trusted-key: handle ", DUMP_PREFIX_NONE, @@ -96,10 +85,6 @@ static inline void dump_options(struct trusted_key_options *o) { } -static inline void dump_payload(struct trusted_key_payload *p) -{ -}
static inline void dump_sess(struct osapsess *s) { } diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile index 7b73ceb..2b1085b 100644 --- a/security/keys/trusted-keys/Makefile +++ b/security/keys/trusted-keys/Makefile @@ -4,5 +4,6 @@ # obj-$(CONFIG_TRUSTED_KEYS) += trusted.o +trusted-y += trusted_common.o trusted-y += trusted_tpm1.o trusted-y += trusted_tpm2.o diff --git a/security/keys/trusted-keys/trusted_common.c b/security/keys/trusted-keys/trusted_common.c new file mode 100644 index 0000000..9bfd081 --- /dev/null +++ b/security/keys/trusted-keys/trusted_common.c @@ -0,0 +1,333 @@ +// SPDX-License-Identifier: GPL-2.0-only +/*
- Copyright (C) 2010 IBM Corporation
- Copyright (c) 2019, Linaro Limited
- Author:
- David Safford safford@us.ibm.com
- Added generic trusted key framework: Sumit Garg sumit.garg@linaro.org
- See Documentation/security/keys/trusted-encrypted.rst
- */
+#include <keys/user-type.h> +#include <keys/trusted-type.h> +#include <linux/capability.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/key-type.h> +#include <linux/module.h> +#include <linux/parser.h> +#include <linux/rcupdate.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/uaccess.h>
+static struct trusted_key_ops *available_tk_ops[] = { +#if defined(CONFIG_TCG_TPM)
- &tpm_trusted_key_ops,
+#endif +}; +static struct trusted_key_ops *tk_ops;
+enum {
- Opt_err,
- Opt_new, Opt_load, Opt_update,
+};
+static const match_table_t key_tokens = {
- {Opt_new, "new"},
- {Opt_load, "load"},
- {Opt_update, "update"},
- {Opt_err, NULL}
+};
+/*
- datablob_parse - parse the keyctl data and fill in the
payload structure
- On success returns 0, otherwise -EINVAL.
- */
+static int datablob_parse(char *datablob, struct trusted_key_payload *p) +{
- substring_t args[MAX_OPT_ARGS];
- long keylen;
- int ret = -EINVAL;
- int key_cmd;
- char *c;
- /* main command */
- c = strsep(&datablob, " \t");
- if (!c)
return -EINVAL;- key_cmd = match_token(c, key_tokens, args);
- switch (key_cmd) {
- case Opt_new:
/* first argument is key size */c = strsep(&datablob, " \t");if (!c)return -EINVAL;ret = kstrtol(c, 10, &keylen);if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)return -EINVAL;p->key_len = keylen;ret = Opt_new;break;- case Opt_load:
/* first argument is sealed blob */c = strsep(&datablob, " \t");if (!c)return -EINVAL;p->blob_len = strlen(c) / 2;if (p->blob_len > MAX_BLOB_SIZE)return -EINVAL;ret = hex2bin(p->blob, c, p->blob_len);if (ret < 0)return -EINVAL;ret = Opt_load;break;- case Opt_update:
ret = Opt_update;break;- case Opt_err:
return -EINVAL;- }
- return ret;
+}
+static struct trusted_key_payload *trusted_payload_alloc(struct key *key) +{
- struct trusted_key_payload *p = NULL;
- int ret;
- ret = key_payload_reserve(key, sizeof(*p));
- if (ret < 0)
return p;- p = kzalloc(sizeof(*p), GFP_KERNEL);
- p->migratable = tk_ops->migratable;
- return p;
+}
+/*
- trusted_instantiate - create a new trusted key
- Unseal an existing trusted blob or, for a new key, get a
- random key, then seal and create a trusted key-type key,
- adding it to the specified keyring.
- On success, return 0. Otherwise return errno.
- */
+static int trusted_instantiate(struct key *key,
struct key_preparsed_payload *prep)+{
- struct trusted_key_payload *payload = NULL;
- size_t datalen = prep->datalen;
- char *datablob;
- int ret = 0;
- int key_cmd;
- size_t key_len;
- if (datalen <= 0 || datalen > 32767 || !prep->data)
return -EINVAL;- datablob = kmalloc(datalen + 1, GFP_KERNEL);
- if (!datablob)
return -ENOMEM;- memcpy(datablob, prep->data, datalen);
- datablob[datalen] = '\0';
- payload = trusted_payload_alloc(key);
- if (!payload) {
ret = -ENOMEM;goto out;- }
- key_cmd = datablob_parse(datablob, payload);
- if (key_cmd < 0) {
ret = key_cmd;goto out;- }
- dump_payload(payload);
- switch (key_cmd) {
- case Opt_load:
ret = tk_ops->unseal(payload, datablob);dump_payload(payload);if (ret < 0)pr_info("trusted_key: key_unseal failed (%d)\n", ret);break;- case Opt_new:
key_len = payload->key_len;ret = tk_ops->get_random(payload->key, key_len);if (ret != key_len) {pr_info("trusted_key: key_create failed (%d)\n", ret);goto out;}ret = tk_ops->seal(payload, datablob);if (ret < 0)pr_info("trusted_key: key_seal failed (%d)\n", ret);break;- default:
ret = -EINVAL;- }
+out:
- kzfree(datablob);
- if (!ret)
rcu_assign_keypointer(key, payload);- else
kzfree(payload);- return ret;
+}
+static void trusted_rcu_free(struct rcu_head *rcu) +{
- struct trusted_key_payload *p;
- p = container_of(rcu, struct trusted_key_payload, rcu);
- kzfree(p);
+}
+/*
- trusted_update - reseal an existing key with new PCR values
- */
+static int trusted_update(struct key *key, struct key_preparsed_payload *prep) +{
- struct trusted_key_payload *p;
- struct trusted_key_payload *new_p;
- size_t datalen = prep->datalen;
- char *datablob;
- int ret = 0;
- if (key_is_negative(key))
return -ENOKEY;- p = key->payload.data[0];
- if (!p->migratable)
return -EPERM;- if (datalen <= 0 || datalen > 32767 || !prep->data)
return -EINVAL;- datablob = kmalloc(datalen + 1, GFP_KERNEL);
- if (!datablob)
return -ENOMEM;- new_p = trusted_payload_alloc(key);
- if (!new_p) {
ret = -ENOMEM;goto out;- }
- memcpy(datablob, prep->data, datalen);
- datablob[datalen] = '\0';
- ret = datablob_parse(datablob, new_p);
- if (ret != Opt_update) {
ret = -EINVAL;kzfree(new_p);goto out;- }
- /* copy old key values, and reseal with new pcrs */
- new_p->migratable = p->migratable;
- new_p->key_len = p->key_len;
- memcpy(new_p->key, p->key, p->key_len);
- dump_payload(p);
- dump_payload(new_p);
- ret = tk_ops->seal(new_p, datablob);
- if (ret < 0) {
pr_info("trusted_key: key_seal failed (%d)\n", ret);kzfree(new_p);goto out;- }
- rcu_assign_keypointer(key, new_p);
- call_rcu(&p->rcu, trusted_rcu_free);
+out:
- kzfree(datablob);
- return ret;
+}
+/*
- trusted_read - copy the sealed blob data to userspace in hex.
- On success, return to userspace the trusted key datablob size.
- */
+static long trusted_read(const struct key *key, char *buffer,
size_t buflen)+{
- const struct trusted_key_payload *p;
- char *bufp;
- int i;
- p = dereference_key_locked(key);
- if (!p)
return -EINVAL;- if (buffer && buflen >= 2 * p->blob_len) {
bufp = buffer;for (i = 0; i < p->blob_len; i++)bufp = hex_byte_pack(bufp, p->blob[i]);- }
- return 2 * p->blob_len;
+}
+/*
- trusted_destroy - clear and free the key's payload
- */
+static void trusted_destroy(struct key *key) +{
- kzfree(key->payload.data[0]);
+}
+struct key_type key_type_trusted = {
- .name = "trusted",
- .instantiate = trusted_instantiate,
- .update = trusted_update,
- .destroy = trusted_destroy,
- .describe = user_describe,
- .read = trusted_read,
+}; +EXPORT_SYMBOL_GPL(key_type_trusted);
+static int __init init_trusted(void) +{
- int i, ret = 0;
- for (i = 0; i < sizeof(available_tk_ops); i++) {
tk_ops = available_tk_ops[i];if (!(tk_ops && tk_ops->init && tk_ops->seal &&tk_ops->unseal && tk_ops->get_random))continue;ret = tk_ops->init();if (ret) {if (tk_ops->cleanup)tk_ops->cleanup();} else {break;}- }
- /*
* encrypted_keys.ko depends on successful load of this module even if* trusted key implementation is not found.*/- if (ret == -ENODEV)
return 0;- return ret;
+}
+static void __exit cleanup_trusted(void) +{
- if (tk_ops->cleanup)
tk_ops->cleanup();+}
+late_initcall(init_trusted); +module_exit(cleanup_trusted);
+MODULE_LICENSE("GPL"); diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c index 8001ab0..32fd1ea 100644 --- a/security/keys/trusted-keys/trusted_tpm1.c +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -1,29 +1,26 @@ // SPDX-License-Identifier: GPL-2.0-only /*
- Copyright (C) 2010 IBM Corporation
- Copyright (c) 2019, Linaro Limited
- Author:
- David Safford safford@us.ibm.com
*/
- Switch to generic trusted key framework: Sumit Garg sumit.garg@linaro.org
- See Documentation/security/keys/trusted-encrypted.rst
#include <crypto/hash_info.h> -#include <linux/uaccess.h> -#include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/parser.h> #include <linux/string.h> #include <linux/err.h> -#include <keys/user-type.h> #include <keys/trusted-type.h> #include <linux/key-type.h> -#include <linux/rcupdate.h> #include <linux/crypto.h> #include <crypto/hash.h> #include <crypto/sha.h> -#include <linux/capability.h> #include <linux/tpm.h> #include <linux/tpm_command.h> @@ -703,7 +700,6 @@ static int key_unseal(struct trusted_key_payload *p, enum { Opt_err,
- Opt_new, Opt_load, Opt_update, Opt_keyhandle, Opt_keyauth, Opt_blobauth, Opt_pcrinfo, Opt_pcrlock, Opt_migratable, Opt_hash,
@@ -712,9 +708,6 @@ enum { }; static const match_table_t key_tokens = {
- {Opt_new, "new"},
- {Opt_load, "load"},
- {Opt_update, "update"}, {Opt_keyhandle, "keyhandle=%s"}, {Opt_keyauth, "keyauth=%s"}, {Opt_blobauth, "blobauth=%s"},
@@ -841,71 +834,6 @@ static int getoptions(char *c, struct trusted_key_payload *pay, return 0; } -/*
- datablob_parse - parse the keyctl data and fill in the
payload and options structures
- On success returns 0, otherwise -EINVAL.
- */
-static int datablob_parse(char *datablob, struct trusted_key_payload *p,
struct trusted_key_options *o)-{
- substring_t args[MAX_OPT_ARGS];
- long keylen;
- int ret = -EINVAL;
- int key_cmd;
- char *c;
- /* main command */
- c = strsep(&datablob, " \t");
- if (!c)
return -EINVAL;- key_cmd = match_token(c, key_tokens, args);
- switch (key_cmd) {
- case Opt_new:
/* first argument is key size */c = strsep(&datablob, " \t");if (!c)return -EINVAL;ret = kstrtol(c, 10, &keylen);if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)return -EINVAL;p->key_len = keylen;ret = getoptions(datablob, p, o);if (ret < 0)return ret;ret = Opt_new;break;- case Opt_load:
/* first argument is sealed blob */c = strsep(&datablob, " \t");if (!c)return -EINVAL;p->blob_len = strlen(c) / 2;if (p->blob_len > MAX_BLOB_SIZE)return -EINVAL;ret = hex2bin(p->blob, c, p->blob_len);if (ret < 0)return -EINVAL;ret = getoptions(datablob, p, o);if (ret < 0)return ret;ret = Opt_load;break;- case Opt_update:
/* all arguments are options */ret = getoptions(datablob, p, o);if (ret < 0)return ret;ret = Opt_update;break;- case Opt_err:
return -EINVAL;break;- }
- return ret;
-}
static struct trusted_key_options *trusted_options_alloc(void) { struct trusted_key_options *options; @@ -926,248 +854,99 @@ static struct trusted_key_options *trusted_options_alloc(void) return options; } -static struct trusted_key_payload *trusted_payload_alloc(struct key *key) +static int tpm_tk_seal(struct trusted_key_payload *p, char *datablob) {
- struct trusted_key_payload *p = NULL;
- int ret;
- ret = key_payload_reserve(key, sizeof *p);
- if (ret < 0)
return p;- p = kzalloc(sizeof *p, GFP_KERNEL);
- if (p)
p->migratable = 1; /* migratable by default */- return p;
-}
-/*
- trusted_instantiate - create a new trusted key
- Unseal an existing trusted blob or, for a new key, get a
- random key, then seal and create a trusted key-type key,
- adding it to the specified keyring.
- On success, return 0. Otherwise return errno.
- */
-static int trusted_instantiate(struct key *key,
struct key_preparsed_payload *prep)-{
- struct trusted_key_payload *payload = NULL; struct trusted_key_options *options = NULL;
- size_t datalen = prep->datalen;
- char *datablob; int ret = 0;
- int key_cmd;
- size_t key_len; int tpm2;
tpm2 = tpm_is_tpm2(chip); if (tpm2 < 0) return tpm2;
- if (datalen <= 0 || datalen > 32767 || !prep->data)
return -EINVAL;- datablob = kmalloc(datalen + 1, GFP_KERNEL);
- if (!datablob)
return -ENOMEM;- memcpy(datablob, prep->data, datalen);
- datablob[datalen] = '\0';
- options = trusted_options_alloc();
- if (!options) {
ret = -ENOMEM;goto out;- }
- payload = trusted_payload_alloc(key);
- if (!payload) {
ret = -ENOMEM;goto out;- }
- if (!options)
return -ENOMEM;
- key_cmd = datablob_parse(datablob, payload, options);
- if (key_cmd < 0) {
ret = key_cmd;
- ret = getoptions(datablob, p, options);
- if (ret < 0) goto out;
- }
- dump_options(options);
if (!options->keyhandle) { ret = -EINVAL; goto out; }
- dump_payload(payload);
- dump_options(options);
- if (tpm2)
ret = tpm2_seal_trusted(chip, p, options);- else
ret = key_seal(p, options);- if (ret < 0) {
pr_info("tpm_trusted_key: key_seal failed (%d)\n", ret);goto out;- }
- switch (key_cmd) {
- case Opt_load:
if (tpm2)ret = tpm2_unseal_trusted(chip, payload, options);elseret = key_unseal(payload, options);dump_payload(payload);dump_options(options);if (ret < 0)pr_info("trusted_key: key_unseal failed (%d)\n", ret);break;- case Opt_new:
key_len = payload->key_len;ret = tpm_get_random(chip, payload->key, key_len);if (ret != key_len) {pr_info("trusted_key: key_create failed (%d)\n", ret);
- if (options->pcrlock) {
ret = pcrlock(options->pcrlock);if (ret < 0) {pr_info("tpm_trusted_key: pcrlock failed (%d)\n", ret); goto out;
if (tpm2)ret = tpm2_seal_trusted(chip, payload, options);elseret = key_seal(payload, options);if (ret < 0)pr_info("trusted_key: key_seal failed (%d)\n", ret);break;- default:
ret = -EINVAL;goto out;- if (!ret && options->pcrlock)
ret = pcrlock(options->pcrlock);out:
- kzfree(datablob); kzfree(options);
- if (!ret)
rcu_assign_keypointer(key, payload);- else
kzfree(payload);} -static void trusted_rcu_free(struct rcu_head *rcu) +static int tpm_tk_unseal(struct trusted_key_payload *p, char *datablob) {
- struct trusted_key_payload *p;
- p = container_of(rcu, struct trusted_key_payload, rcu);
- kzfree(p);
-}
-/*
- trusted_update - reseal an existing key with new PCR values
- */
-static int trusted_update(struct key *key, struct key_preparsed_payload *prep) -{
- struct trusted_key_payload *p;
- struct trusted_key_payload *new_p;
- struct trusted_key_options *new_o;
- size_t datalen = prep->datalen;
- char *datablob;
- struct trusted_key_options *options = NULL; int ret = 0;
- int tpm2;
- if (key_is_negative(key))
return -ENOKEY;- p = key->payload.data[0];
- if (!p->migratable)
return -EPERM;- if (datalen <= 0 || datalen > 32767 || !prep->data)
return -EINVAL;
- tpm2 = tpm_is_tpm2(chip);
- if (tpm2 < 0)
return tpm2;
- datablob = kmalloc(datalen + 1, GFP_KERNEL);
- if (!datablob)
- options = trusted_options_alloc();
- if (!options) return -ENOMEM;
- new_o = trusted_options_alloc();
- if (!new_o) {
ret = -ENOMEM;goto out;- }
- new_p = trusted_payload_alloc(key);
- if (!new_p) {
ret = -ENOMEM;goto out;- }
- memcpy(datablob, prep->data, datalen);
- datablob[datalen] = '\0';
- ret = datablob_parse(datablob, new_p, new_o);
- if (ret != Opt_update) {
ret = -EINVAL;kzfree(new_p);
- ret = getoptions(datablob, p, options);
- if (ret < 0) goto out;
- }
- dump_options(options);
- if (!new_o->keyhandle) {
- if (!options->keyhandle) { ret = -EINVAL;
kzfree(new_p);
- /* copy old key values, and reseal with new pcrs */
- new_p->migratable = p->migratable;
- new_p->key_len = p->key_len;
- memcpy(new_p->key, p->key, p->key_len);
- dump_payload(p);
- dump_payload(new_p);
- if (tpm2)
ret = tpm2_unseal_trusted(chip, p, options);- else
ret = key_unseal(p, options);- if (ret < 0)
pr_info("tpm_trusted_key: key_unseal failed (%d)\n", ret);
- ret = key_seal(new_p, new_o);
- if (ret < 0) {
pr_info("trusted_key: key_seal failed (%d)\n", ret);kzfree(new_p);goto out;- }
- if (new_o->pcrlock) {
ret = pcrlock(new_o->pcrlock);
- if (options->pcrlock) {
ret = pcrlock(options->pcrlock);
pr_info("trusted_key: pcrlock failed (%d)\n", ret);kzfree(new_p);
pr_info("tpm_trusted_key: pcrlock failed (%d)\n", ret); goto out;
- rcu_assign_keypointer(key, new_p);
- call_rcu(&p->rcu, trusted_rcu_free);
out:
- kzfree(datablob);
- kzfree(new_o);
- kzfree(options); return ret;
} -/*
- trusted_read - copy the sealed blob data to userspace in hex.
- On success, return to userspace the trusted key datablob size.
- */
-static long trusted_read(const struct key *key, char *buffer,
size_t buflen)-{
- const struct trusted_key_payload *p;
- char *bufp;
- int i;
- p = dereference_key_locked(key);
- if (!p)
return -EINVAL;- if (buffer && buflen >= 2 * p->blob_len) {
bufp = buffer;for (i = 0; i < p->blob_len; i++)bufp = hex_byte_pack(bufp, p->blob[i]);- }
- return 2 * p->blob_len;
-}
-/*
- trusted_destroy - clear and free the key's payload
- */
-static void trusted_destroy(struct key *key) +int tpm_tk_get_random(unsigned char *key, size_t key_len) {
- kzfree(key->payload.data[0]);
- return tpm_get_random(chip, key, key_len);
} -struct key_type key_type_trusted = {
- .name = "trusted",
- .instantiate = trusted_instantiate,
- .update = trusted_update,
- .destroy = trusted_destroy,
- .describe = user_describe,
- .read = trusted_read,
-};
-EXPORT_SYMBOL_GPL(key_type_trusted);
static void trusted_shash_release(void) { if (hashalg) @@ -1182,14 +961,14 @@ static int __init trusted_shash_alloc(void) hmacalg = crypto_alloc_shash(hmac_alg, 0, 0); if (IS_ERR(hmacalg)) {
pr_info("trusted_key: could not allocate crypto %s\n",
pr_info("tpm_trusted_key: could not allocate crypto %s\n", hmac_alg);hashalg = crypto_alloc_shash(hash_alg, 0, 0); if (IS_ERR(hashalg)) {
pr_info("trusted_key: could not allocate crypto %s\n",
pr_info("tpm_trusted_key: could not allocate crypto %s\n", hash_alg);@@ -1217,16 +996,13 @@ static int __init init_digests(void) return 0; } -static int __init init_trusted(void) +static int __init init_tpm_trusted(void) { int ret;
- /* encrypted_keys.ko depends on successful load of this module even if
* TPM is not used.*/return 0;
return -ENODEV;ret = init_digests(); if (ret < 0) @@ -1247,7 +1023,7 @@ static int __init init_trusted(void) return ret; } -static void __exit cleanup_trusted(void) +static void __exit cleanup_tpm_trusted(void) { if (chip) { put_device(&chip->dev); @@ -1257,7 +1033,12 @@ static void __exit cleanup_trusted(void) } } -late_initcall(init_trusted); -module_exit(cleanup_trusted);
-MODULE_LICENSE("GPL"); +struct trusted_key_ops tpm_trusted_key_ops = {
- .migratable = 1, /* migratable by default */
- .init = init_tpm_trusted,
- .seal = tpm_tk_seal,
- .unseal = tpm_tk_unseal,
- .get_random = tpm_tk_get_random,
- .cleanup = cleanup_tpm_trusted,
+}; +EXPORT_SYMBOL_GPL(tpm_trusted_key_ops);
Everywhere: do not use 'tk'. Use 'trusted' in those places. We do not want a new acronym.
/Jarkko
On Mon, 1 Jun 2020 at 07:30, Jarkko Sakkinen jarkko.sakkinen@linux.intel.com wrote:
On Wed, May 06, 2020 at 03:10:14PM +0530, Sumit Garg wrote:
Current trusted keys framework is tightly coupled to use TPM device as an underlying implementation which makes it difficult for implementations like Trusted Execution Environment (TEE) etc. to provide trusked keys support in case platform doesn't posses a TPM device.
So this patch tries to add generic trusted keys framework where underlying implemtations like TPM, TEE etc. could be easily plugged-in.
Suggested-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: Sumit Garg sumit.garg@linaro.org
include/keys/trusted-type.h | 45 ++++ include/keys/trusted_tpm.h | 15 -- security/keys/trusted-keys/Makefile | 1 + security/keys/trusted-keys/trusted_common.c | 333 +++++++++++++++++++++++++++
I think trusted_core.c would be a better name (less ambiguous).
Okay.
security/keys/trusted-keys/trusted_tpm1.c | 335 +++++----------------------- 5 files changed, 437 insertions(+), 292 deletions(-) create mode 100644 security/keys/trusted-keys/trusted_common.c
diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h index a94c03a..5559010 100644 --- a/include/keys/trusted-type.h +++ b/include/keys/trusted-type.h @@ -40,6 +40,51 @@ struct trusted_key_options { uint32_t policyhandle; };
+struct trusted_key_ops {
/** flag to indicate if trusted key implementation supports migration* or not.*/unsigned char migratable;/* trusted key init */int (*init)(void);/* Init a key. */
This API isn't initializing a key but rather the underlying interface (see init_tpm_trusted()). So how about:
/* Initialize key interface */
/* seal a trusted key */int (*seal)(struct trusted_key_payload *p, char *datablob);/* Seal a key. */
Ack.
/* unseal a trusted key */int (*unseal)(struct trusted_key_payload *p, char *datablob);/* Unseal a key. */
Ack.
/* get random trusted key */int (*get_random)(unsigned char *key, size_t key_len);/* Get a randomized key. */
Ack.
/* trusted key cleanup */void (*cleanup)(void);Please remove this from this commit since it is not in use in the scope of this commit. You should instead make a separate commit just for this callback, which explains what it is and how it will be used in the follow up commits.
This API is pretty much relevant to TPM as well (see: cleanup_tpm_trusted()) but I guess "cleanup()" terminology is bringing up some confusion, so how about to call it "exit()" instead?
+};
extern struct key_type key_type_trusted; +#if defined(CONFIG_TCG_TPM) +extern struct trusted_key_ops tpm_trusted_key_ops; +#endif
+#define TRUSTED_DEBUG 0
+#if TRUSTED_DEBUG +static inline void dump_payload(struct trusted_key_payload *p) +{
pr_info("trusted_key: key_len %d\n", p->key_len);print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE,16, 1, p->key, p->key_len, 0);pr_info("trusted_key: bloblen %d\n", p->blob_len);print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE,16, 1, p->blob, p->blob_len, 0);pr_info("trusted_key: migratable %d\n", p->migratable);+} +#else +static inline void dump_payload(struct trusted_key_payload *p) +{ +} +#endif
#endif /* _KEYS_TRUSTED_TYPE_H */ diff --git a/include/keys/trusted_tpm.h b/include/keys/trusted_tpm.h index a56d8e1..5753231 100644 --- a/include/keys/trusted_tpm.h +++ b/include/keys/trusted_tpm.h @@ -60,17 +60,6 @@ static inline void dump_options(struct trusted_key_options *o) 16, 1, o->pcrinfo, o->pcrinfo_len, 0); }
-static inline void dump_payload(struct trusted_key_payload *p) -{
pr_info("trusted_key: key_len %d\n", p->key_len);print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE,16, 1, p->key, p->key_len, 0);pr_info("trusted_key: bloblen %d\n", p->blob_len);print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE,16, 1, p->blob, p->blob_len, 0);pr_info("trusted_key: migratable %d\n", p->migratable);-}
static inline void dump_sess(struct osapsess *s) { print_hex_dump(KERN_INFO, "trusted-key: handle ", DUMP_PREFIX_NONE, @@ -96,10 +85,6 @@ static inline void dump_options(struct trusted_key_options *o) { }
-static inline void dump_payload(struct trusted_key_payload *p) -{ -}
static inline void dump_sess(struct osapsess *s) { } diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile index 7b73ceb..2b1085b 100644 --- a/security/keys/trusted-keys/Makefile +++ b/security/keys/trusted-keys/Makefile @@ -4,5 +4,6 @@ #
obj-$(CONFIG_TRUSTED_KEYS) += trusted.o +trusted-y += trusted_common.o trusted-y += trusted_tpm1.o trusted-y += trusted_tpm2.o diff --git a/security/keys/trusted-keys/trusted_common.c b/security/keys/trusted-keys/trusted_common.c new file mode 100644 index 0000000..9bfd081 --- /dev/null +++ b/security/keys/trusted-keys/trusted_common.c @@ -0,0 +1,333 @@ +// SPDX-License-Identifier: GPL-2.0-only +/*
- Copyright (C) 2010 IBM Corporation
- Copyright (c) 2019, Linaro Limited
- Author:
- David Safford safford@us.ibm.com
- Added generic trusted key framework: Sumit Garg sumit.garg@linaro.org
- See Documentation/security/keys/trusted-encrypted.rst
- */
+#include <keys/user-type.h> +#include <keys/trusted-type.h> +#include <linux/capability.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/key-type.h> +#include <linux/module.h> +#include <linux/parser.h> +#include <linux/rcupdate.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/uaccess.h>
+static struct trusted_key_ops *available_tk_ops[] = { +#if defined(CONFIG_TCG_TPM)
&tpm_trusted_key_ops,+#endif +}; +static struct trusted_key_ops *tk_ops;
+enum {
Opt_err,Opt_new, Opt_load, Opt_update,+};
+static const match_table_t key_tokens = {
{Opt_new, "new"},{Opt_load, "load"},{Opt_update, "update"},{Opt_err, NULL}+};
+/*
- datablob_parse - parse the keyctl data and fill in the
payload structure
- On success returns 0, otherwise -EINVAL.
- */
+static int datablob_parse(char *datablob, struct trusted_key_payload *p) +{
substring_t args[MAX_OPT_ARGS];long keylen;int ret = -EINVAL;int key_cmd;char *c;/* main command */c = strsep(&datablob, " \t");if (!c)return -EINVAL;key_cmd = match_token(c, key_tokens, args);switch (key_cmd) {case Opt_new:/* first argument is key size */c = strsep(&datablob, " \t");if (!c)return -EINVAL;ret = kstrtol(c, 10, &keylen);if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)return -EINVAL;p->key_len = keylen;ret = Opt_new;break;case Opt_load:/* first argument is sealed blob */c = strsep(&datablob, " \t");if (!c)return -EINVAL;p->blob_len = strlen(c) / 2;if (p->blob_len > MAX_BLOB_SIZE)return -EINVAL;ret = hex2bin(p->blob, c, p->blob_len);if (ret < 0)return -EINVAL;ret = Opt_load;break;case Opt_update:ret = Opt_update;break;case Opt_err:return -EINVAL;}return ret;+}
+static struct trusted_key_payload *trusted_payload_alloc(struct key *key) +{
struct trusted_key_payload *p = NULL;int ret;ret = key_payload_reserve(key, sizeof(*p));if (ret < 0)return p;p = kzalloc(sizeof(*p), GFP_KERNEL);p->migratable = tk_ops->migratable;return p;+}
+/*
- trusted_instantiate - create a new trusted key
- Unseal an existing trusted blob or, for a new key, get a
- random key, then seal and create a trusted key-type key,
- adding it to the specified keyring.
- On success, return 0. Otherwise return errno.
- */
+static int trusted_instantiate(struct key *key,
struct key_preparsed_payload *prep)+{
struct trusted_key_payload *payload = NULL;size_t datalen = prep->datalen;char *datablob;int ret = 0;int key_cmd;size_t key_len;if (datalen <= 0 || datalen > 32767 || !prep->data)return -EINVAL;datablob = kmalloc(datalen + 1, GFP_KERNEL);if (!datablob)return -ENOMEM;memcpy(datablob, prep->data, datalen);datablob[datalen] = '\0';payload = trusted_payload_alloc(key);if (!payload) {ret = -ENOMEM;goto out;}key_cmd = datablob_parse(datablob, payload);if (key_cmd < 0) {ret = key_cmd;goto out;}dump_payload(payload);switch (key_cmd) {case Opt_load:ret = tk_ops->unseal(payload, datablob);dump_payload(payload);if (ret < 0)pr_info("trusted_key: key_unseal failed (%d)\n", ret);break;case Opt_new:key_len = payload->key_len;ret = tk_ops->get_random(payload->key, key_len);if (ret != key_len) {pr_info("trusted_key: key_create failed (%d)\n", ret);goto out;}ret = tk_ops->seal(payload, datablob);if (ret < 0)pr_info("trusted_key: key_seal failed (%d)\n", ret);break;default:ret = -EINVAL;}+out:
kzfree(datablob);if (!ret)rcu_assign_keypointer(key, payload);elsekzfree(payload);return ret;+}
+static void trusted_rcu_free(struct rcu_head *rcu) +{
struct trusted_key_payload *p;p = container_of(rcu, struct trusted_key_payload, rcu);kzfree(p);+}
+/*
- trusted_update - reseal an existing key with new PCR values
- */
+static int trusted_update(struct key *key, struct key_preparsed_payload *prep) +{
struct trusted_key_payload *p;struct trusted_key_payload *new_p;size_t datalen = prep->datalen;char *datablob;int ret = 0;if (key_is_negative(key))return -ENOKEY;p = key->payload.data[0];if (!p->migratable)return -EPERM;if (datalen <= 0 || datalen > 32767 || !prep->data)return -EINVAL;datablob = kmalloc(datalen + 1, GFP_KERNEL);if (!datablob)return -ENOMEM;new_p = trusted_payload_alloc(key);if (!new_p) {ret = -ENOMEM;goto out;}memcpy(datablob, prep->data, datalen);datablob[datalen] = '\0';ret = datablob_parse(datablob, new_p);if (ret != Opt_update) {ret = -EINVAL;kzfree(new_p);goto out;}/* copy old key values, and reseal with new pcrs */new_p->migratable = p->migratable;new_p->key_len = p->key_len;memcpy(new_p->key, p->key, p->key_len);dump_payload(p);dump_payload(new_p);ret = tk_ops->seal(new_p, datablob);if (ret < 0) {pr_info("trusted_key: key_seal failed (%d)\n", ret);kzfree(new_p);goto out;}rcu_assign_keypointer(key, new_p);call_rcu(&p->rcu, trusted_rcu_free);+out:
kzfree(datablob);return ret;+}
+/*
- trusted_read - copy the sealed blob data to userspace in hex.
- On success, return to userspace the trusted key datablob size.
- */
+static long trusted_read(const struct key *key, char *buffer,
size_t buflen)+{
const struct trusted_key_payload *p;char *bufp;int i;p = dereference_key_locked(key);if (!p)return -EINVAL;if (buffer && buflen >= 2 * p->blob_len) {bufp = buffer;for (i = 0; i < p->blob_len; i++)bufp = hex_byte_pack(bufp, p->blob[i]);}return 2 * p->blob_len;+}
+/*
- trusted_destroy - clear and free the key's payload
- */
+static void trusted_destroy(struct key *key) +{
kzfree(key->payload.data[0]);+}
+struct key_type key_type_trusted = {
.name = "trusted",.instantiate = trusted_instantiate,.update = trusted_update,.destroy = trusted_destroy,.describe = user_describe,.read = trusted_read,+}; +EXPORT_SYMBOL_GPL(key_type_trusted);
+static int __init init_trusted(void) +{
int i, ret = 0;for (i = 0; i < sizeof(available_tk_ops); i++) {tk_ops = available_tk_ops[i];if (!(tk_ops && tk_ops->init && tk_ops->seal &&tk_ops->unseal && tk_ops->get_random))continue;ret = tk_ops->init();if (ret) {if (tk_ops->cleanup)tk_ops->cleanup();} else {break;}}/** encrypted_keys.ko depends on successful load of this module even if* trusted key implementation is not found.*/if (ret == -ENODEV)return 0;return ret;+}
+static void __exit cleanup_trusted(void) +{
if (tk_ops->cleanup)tk_ops->cleanup();+}
+late_initcall(init_trusted); +module_exit(cleanup_trusted);
+MODULE_LICENSE("GPL"); diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c index 8001ab0..32fd1ea 100644 --- a/security/keys/trusted-keys/trusted_tpm1.c +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -1,29 +1,26 @@ // SPDX-License-Identifier: GPL-2.0-only /*
- Copyright (C) 2010 IBM Corporation
- Copyright (c) 2019, Linaro Limited
- Author:
- David Safford safford@us.ibm.com
*/
- Switch to generic trusted key framework: Sumit Garg sumit.garg@linaro.org
- See Documentation/security/keys/trusted-encrypted.rst
#include <crypto/hash_info.h> -#include <linux/uaccess.h> -#include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/parser.h> #include <linux/string.h> #include <linux/err.h> -#include <keys/user-type.h> #include <keys/trusted-type.h> #include <linux/key-type.h> -#include <linux/rcupdate.h> #include <linux/crypto.h> #include <crypto/hash.h> #include <crypto/sha.h> -#include <linux/capability.h> #include <linux/tpm.h> #include <linux/tpm_command.h>
@@ -703,7 +700,6 @@ static int key_unseal(struct trusted_key_payload *p,
enum { Opt_err,
Opt_new, Opt_load, Opt_update, Opt_keyhandle, Opt_keyauth, Opt_blobauth, Opt_pcrinfo, Opt_pcrlock, Opt_migratable, Opt_hash,@@ -712,9 +708,6 @@ enum { };
static const match_table_t key_tokens = {
{Opt_new, "new"},{Opt_load, "load"},{Opt_update, "update"}, {Opt_keyhandle, "keyhandle=%s"}, {Opt_keyauth, "keyauth=%s"}, {Opt_blobauth, "blobauth=%s"},@@ -841,71 +834,6 @@ static int getoptions(char *c, struct trusted_key_payload *pay, return 0; }
-/*
- datablob_parse - parse the keyctl data and fill in the
payload and options structures
- On success returns 0, otherwise -EINVAL.
- */
-static int datablob_parse(char *datablob, struct trusted_key_payload *p,
struct trusted_key_options *o)-{
substring_t args[MAX_OPT_ARGS];long keylen;int ret = -EINVAL;int key_cmd;char *c;/* main command */c = strsep(&datablob, " \t");if (!c)return -EINVAL;key_cmd = match_token(c, key_tokens, args);switch (key_cmd) {case Opt_new:/* first argument is key size */c = strsep(&datablob, " \t");if (!c)return -EINVAL;ret = kstrtol(c, 10, &keylen);if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)return -EINVAL;p->key_len = keylen;ret = getoptions(datablob, p, o);if (ret < 0)return ret;ret = Opt_new;break;case Opt_load:/* first argument is sealed blob */c = strsep(&datablob, " \t");if (!c)return -EINVAL;p->blob_len = strlen(c) / 2;if (p->blob_len > MAX_BLOB_SIZE)return -EINVAL;ret = hex2bin(p->blob, c, p->blob_len);if (ret < 0)return -EINVAL;ret = getoptions(datablob, p, o);if (ret < 0)return ret;ret = Opt_load;break;case Opt_update:/* all arguments are options */ret = getoptions(datablob, p, o);if (ret < 0)return ret;ret = Opt_update;break;case Opt_err:return -EINVAL;break;}return ret;-}
static struct trusted_key_options *trusted_options_alloc(void) { struct trusted_key_options *options; @@ -926,248 +854,99 @@ static struct trusted_key_options *trusted_options_alloc(void) return options; }
-static struct trusted_key_payload *trusted_payload_alloc(struct key *key) +static int tpm_tk_seal(struct trusted_key_payload *p, char *datablob) {
struct trusted_key_payload *p = NULL;int ret;ret = key_payload_reserve(key, sizeof *p);if (ret < 0)return p;p = kzalloc(sizeof *p, GFP_KERNEL);if (p)p->migratable = 1; /* migratable by default */return p;-}
-/*
- trusted_instantiate - create a new trusted key
- Unseal an existing trusted blob or, for a new key, get a
- random key, then seal and create a trusted key-type key,
- adding it to the specified keyring.
- On success, return 0. Otherwise return errno.
- */
-static int trusted_instantiate(struct key *key,
struct key_preparsed_payload *prep)-{
struct trusted_key_payload *payload = NULL; struct trusted_key_options *options = NULL;size_t datalen = prep->datalen;char *datablob; int ret = 0;int key_cmd;size_t key_len; int tpm2; tpm2 = tpm_is_tpm2(chip); if (tpm2 < 0) return tpm2;if (datalen <= 0 || datalen > 32767 || !prep->data)return -EINVAL;datablob = kmalloc(datalen + 1, GFP_KERNEL);if (!datablob)return -ENOMEM;memcpy(datablob, prep->data, datalen);datablob[datalen] = '\0';options = trusted_options_alloc();if (!options) {ret = -ENOMEM;goto out;}payload = trusted_payload_alloc(key);if (!payload) {ret = -ENOMEM;goto out;}
if (!options)return -ENOMEM;
key_cmd = datablob_parse(datablob, payload, options);if (key_cmd < 0) {ret = key_cmd;
ret = getoptions(datablob, p, options);if (ret < 0) goto out;
}
dump_options(options); if (!options->keyhandle) { ret = -EINVAL; goto out; }
dump_payload(payload);dump_options(options);
if (tpm2)ret = tpm2_seal_trusted(chip, p, options);elseret = key_seal(p, options);if (ret < 0) {pr_info("tpm_trusted_key: key_seal failed (%d)\n", ret);goto out;}
switch (key_cmd) {case Opt_load:if (tpm2)ret = tpm2_unseal_trusted(chip, payload, options);elseret = key_unseal(payload, options);dump_payload(payload);dump_options(options);if (ret < 0)pr_info("trusted_key: key_unseal failed (%d)\n", ret);break;case Opt_new:key_len = payload->key_len;ret = tpm_get_random(chip, payload->key, key_len);if (ret != key_len) {pr_info("trusted_key: key_create failed (%d)\n", ret);
if (options->pcrlock) {ret = pcrlock(options->pcrlock);if (ret < 0) {pr_info("tpm_trusted_key: pcrlock failed (%d)\n", ret); goto out; }
if (tpm2)ret = tpm2_seal_trusted(chip, payload, options);elseret = key_seal(payload, options);if (ret < 0)pr_info("trusted_key: key_seal failed (%d)\n", ret);break;default:ret = -EINVAL;goto out; }if (!ret && options->pcrlock)ret = pcrlock(options->pcrlock);out:
kzfree(datablob); kzfree(options);if (!ret)rcu_assign_keypointer(key, payload);elsekzfree(payload); return ret;}
-static void trusted_rcu_free(struct rcu_head *rcu) +static int tpm_tk_unseal(struct trusted_key_payload *p, char *datablob) {
struct trusted_key_payload *p;p = container_of(rcu, struct trusted_key_payload, rcu);kzfree(p);-}
-/*
- trusted_update - reseal an existing key with new PCR values
- */
-static int trusted_update(struct key *key, struct key_preparsed_payload *prep) -{
struct trusted_key_payload *p;struct trusted_key_payload *new_p;struct trusted_key_options *new_o;size_t datalen = prep->datalen;char *datablob;
struct trusted_key_options *options = NULL; int ret = 0;int tpm2;
if (key_is_negative(key))return -ENOKEY;p = key->payload.data[0];if (!p->migratable)return -EPERM;if (datalen <= 0 || datalen > 32767 || !prep->data)return -EINVAL;
tpm2 = tpm_is_tpm2(chip);if (tpm2 < 0)return tpm2;
datablob = kmalloc(datalen + 1, GFP_KERNEL);if (!datablob)
options = trusted_options_alloc();if (!options) return -ENOMEM;
new_o = trusted_options_alloc();if (!new_o) {ret = -ENOMEM;goto out;}new_p = trusted_payload_alloc(key);if (!new_p) {ret = -ENOMEM;goto out;}memcpy(datablob, prep->data, datalen);datablob[datalen] = '\0';ret = datablob_parse(datablob, new_p, new_o);if (ret != Opt_update) {ret = -EINVAL;kzfree(new_p);
ret = getoptions(datablob, p, options);if (ret < 0) goto out;
}
dump_options(options);
if (!new_o->keyhandle) {
if (!options->keyhandle) { ret = -EINVAL;
kzfree(new_p); goto out; }/* copy old key values, and reseal with new pcrs */new_p->migratable = p->migratable;new_p->key_len = p->key_len;memcpy(new_p->key, p->key, p->key_len);dump_payload(p);dump_payload(new_p);
if (tpm2)ret = tpm2_unseal_trusted(chip, p, options);elseret = key_unseal(p, options);if (ret < 0)pr_info("tpm_trusted_key: key_unseal failed (%d)\n", ret);
ret = key_seal(new_p, new_o);if (ret < 0) {pr_info("trusted_key: key_seal failed (%d)\n", ret);kzfree(new_p);goto out;}if (new_o->pcrlock) {ret = pcrlock(new_o->pcrlock);
if (options->pcrlock) {ret = pcrlock(options->pcrlock); if (ret < 0) {
pr_info("trusted_key: pcrlock failed (%d)\n", ret);kzfree(new_p);
pr_info("tpm_trusted_key: pcrlock failed (%d)\n", ret); goto out; } }
rcu_assign_keypointer(key, new_p);call_rcu(&p->rcu, trusted_rcu_free);out:
kzfree(datablob);kzfree(new_o);
kzfree(options); return ret;}
-/*
- trusted_read - copy the sealed blob data to userspace in hex.
- On success, return to userspace the trusted key datablob size.
- */
-static long trusted_read(const struct key *key, char *buffer,
size_t buflen)-{
const struct trusted_key_payload *p;char *bufp;int i;p = dereference_key_locked(key);if (!p)return -EINVAL;if (buffer && buflen >= 2 * p->blob_len) {bufp = buffer;for (i = 0; i < p->blob_len; i++)bufp = hex_byte_pack(bufp, p->blob[i]);}return 2 * p->blob_len;-}
-/*
- trusted_destroy - clear and free the key's payload
- */
-static void trusted_destroy(struct key *key) +int tpm_tk_get_random(unsigned char *key, size_t key_len) {
kzfree(key->payload.data[0]);
return tpm_get_random(chip, key, key_len);}
-struct key_type key_type_trusted = {
.name = "trusted",.instantiate = trusted_instantiate,.update = trusted_update,.destroy = trusted_destroy,.describe = user_describe,.read = trusted_read,-};
-EXPORT_SYMBOL_GPL(key_type_trusted);
static void trusted_shash_release(void) { if (hashalg) @@ -1182,14 +961,14 @@ static int __init trusted_shash_alloc(void)
hmacalg = crypto_alloc_shash(hmac_alg, 0, 0); if (IS_ERR(hmacalg)) {
pr_info("trusted_key: could not allocate crypto %s\n",
pr_info("tpm_trusted_key: could not allocate crypto %s\n", hmac_alg); return PTR_ERR(hmacalg); } hashalg = crypto_alloc_shash(hash_alg, 0, 0); if (IS_ERR(hashalg)) {
pr_info("trusted_key: could not allocate crypto %s\n",
pr_info("tpm_trusted_key: could not allocate crypto %s\n", hash_alg); ret = PTR_ERR(hashalg); goto hashalg_fail;@@ -1217,16 +996,13 @@ static int __init init_digests(void) return 0; }
-static int __init init_trusted(void) +static int __init init_tpm_trusted(void) { int ret;
/* encrypted_keys.ko depends on successful load of this module even if* TPM is not used.*/ chip = tpm_default_chip(); if (!chip)return 0;
return -ENODEV; ret = init_digests(); if (ret < 0)@@ -1247,7 +1023,7 @@ static int __init init_trusted(void) return ret; }
-static void __exit cleanup_trusted(void) +static void __exit cleanup_tpm_trusted(void) { if (chip) { put_device(&chip->dev); @@ -1257,7 +1033,12 @@ static void __exit cleanup_trusted(void) } }
-late_initcall(init_trusted); -module_exit(cleanup_trusted);
-MODULE_LICENSE("GPL"); +struct trusted_key_ops tpm_trusted_key_ops = {
.migratable = 1, /* migratable by default */.init = init_tpm_trusted,.seal = tpm_tk_seal,.unseal = tpm_tk_unseal,.get_random = tpm_tk_get_random,.cleanup = cleanup_tpm_trusted,+}; +EXPORT_SYMBOL_GPL(tpm_trusted_key_ops);
Everywhere: do not use 'tk'. Use 'trusted' in those places. We do not want a new acronym.
Okay.
-Sumit
/Jarkko
On Mon, Jun 01, 2020 at 02:20:26PM +0530, Sumit Garg wrote:
On Mon, 1 Jun 2020 at 07:30, Jarkko Sakkinen jarkko.sakkinen@linux.intel.com wrote:
On Wed, May 06, 2020 at 03:10:14PM +0530, Sumit Garg wrote:
Current trusted keys framework is tightly coupled to use TPM device as an underlying implementation which makes it difficult for implementations like Trusted Execution Environment (TEE) etc. to provide trusked keys support in case platform doesn't posses a TPM device.
So this patch tries to add generic trusted keys framework where underlying implemtations like TPM, TEE etc. could be easily plugged-in.
Suggested-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: Sumit Garg sumit.garg@linaro.org
include/keys/trusted-type.h | 45 ++++ include/keys/trusted_tpm.h | 15 -- security/keys/trusted-keys/Makefile | 1 + security/keys/trusted-keys/trusted_common.c | 333 +++++++++++++++++++++++++++
I think trusted_core.c would be a better name (less ambiguous).
Okay.
security/keys/trusted-keys/trusted_tpm1.c | 335 +++++----------------------- 5 files changed, 437 insertions(+), 292 deletions(-) create mode 100644 security/keys/trusted-keys/trusted_common.c
diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h index a94c03a..5559010 100644 --- a/include/keys/trusted-type.h +++ b/include/keys/trusted-type.h @@ -40,6 +40,51 @@ struct trusted_key_options { uint32_t policyhandle; };
+struct trusted_key_ops {
/** flag to indicate if trusted key implementation supports migration* or not.*/unsigned char migratable;/* trusted key init */int (*init)(void);/* Init a key. */
This API isn't initializing a key but rather the underlying interface (see init_tpm_trusted()). So how about:
/* Initialize key interface */
Sure (also for others can use common sense).
/* seal a trusted key */int (*seal)(struct trusted_key_payload *p, char *datablob);/* Seal a key. */
Ack.
/* unseal a trusted key */int (*unseal)(struct trusted_key_payload *p, char *datablob);/* Unseal a key. */
Ack.
/* get random trusted key */int (*get_random)(unsigned char *key, size_t key_len);/* Get a randomized key. */
Ack.
/* trusted key cleanup */void (*cleanup)(void);Please remove this from this commit since it is not in use in the scope of this commit. You should instead make a separate commit just for this callback, which explains what it is and how it will be used in the follow up commits.
This API is pretty much relevant to TPM as well (see: cleanup_tpm_trusted()) but I guess "cleanup()" terminology is bringing up some confusion, so how about to call it "exit()" instead?
+};
extern struct key_type key_type_trusted; +#if defined(CONFIG_TCG_TPM) +extern struct trusted_key_ops tpm_trusted_key_ops; +#endif
+#define TRUSTED_DEBUG 0
+#if TRUSTED_DEBUG +static inline void dump_payload(struct trusted_key_payload *p) +{
pr_info("trusted_key: key_len %d\n", p->key_len);print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE,16, 1, p->key, p->key_len, 0);pr_info("trusted_key: bloblen %d\n", p->blob_len);print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE,16, 1, p->blob, p->blob_len, 0);pr_info("trusted_key: migratable %d\n", p->migratable);+} +#else +static inline void dump_payload(struct trusted_key_payload *p) +{ +} +#endif
#endif /* _KEYS_TRUSTED_TYPE_H */ diff --git a/include/keys/trusted_tpm.h b/include/keys/trusted_tpm.h index a56d8e1..5753231 100644 --- a/include/keys/trusted_tpm.h +++ b/include/keys/trusted_tpm.h @@ -60,17 +60,6 @@ static inline void dump_options(struct trusted_key_options *o) 16, 1, o->pcrinfo, o->pcrinfo_len, 0); }
-static inline void dump_payload(struct trusted_key_payload *p) -{
pr_info("trusted_key: key_len %d\n", p->key_len);print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE,16, 1, p->key, p->key_len, 0);pr_info("trusted_key: bloblen %d\n", p->blob_len);print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE,16, 1, p->blob, p->blob_len, 0);pr_info("trusted_key: migratable %d\n", p->migratable);-}
static inline void dump_sess(struct osapsess *s) { print_hex_dump(KERN_INFO, "trusted-key: handle ", DUMP_PREFIX_NONE, @@ -96,10 +85,6 @@ static inline void dump_options(struct trusted_key_options *o) { }
-static inline void dump_payload(struct trusted_key_payload *p) -{ -}
static inline void dump_sess(struct osapsess *s) { } diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile index 7b73ceb..2b1085b 100644 --- a/security/keys/trusted-keys/Makefile +++ b/security/keys/trusted-keys/Makefile @@ -4,5 +4,6 @@ #
obj-$(CONFIG_TRUSTED_KEYS) += trusted.o +trusted-y += trusted_common.o trusted-y += trusted_tpm1.o trusted-y += trusted_tpm2.o diff --git a/security/keys/trusted-keys/trusted_common.c b/security/keys/trusted-keys/trusted_common.c new file mode 100644 index 0000000..9bfd081 --- /dev/null +++ b/security/keys/trusted-keys/trusted_common.c @@ -0,0 +1,333 @@ +// SPDX-License-Identifier: GPL-2.0-only +/*
- Copyright (C) 2010 IBM Corporation
- Copyright (c) 2019, Linaro Limited
- Author:
- David Safford safford@us.ibm.com
- Added generic trusted key framework: Sumit Garg sumit.garg@linaro.org
- See Documentation/security/keys/trusted-encrypted.rst
- */
+#include <keys/user-type.h> +#include <keys/trusted-type.h> +#include <linux/capability.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/key-type.h> +#include <linux/module.h> +#include <linux/parser.h> +#include <linux/rcupdate.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/uaccess.h>
+static struct trusted_key_ops *available_tk_ops[] = { +#if defined(CONFIG_TCG_TPM)
&tpm_trusted_key_ops,+#endif +}; +static struct trusted_key_ops *tk_ops;
+enum {
Opt_err,Opt_new, Opt_load, Opt_update,+};
+static const match_table_t key_tokens = {
{Opt_new, "new"},{Opt_load, "load"},{Opt_update, "update"},{Opt_err, NULL}+};
+/*
- datablob_parse - parse the keyctl data and fill in the
payload structure
- On success returns 0, otherwise -EINVAL.
- */
+static int datablob_parse(char *datablob, struct trusted_key_payload *p) +{
substring_t args[MAX_OPT_ARGS];long keylen;int ret = -EINVAL;int key_cmd;char *c;/* main command */c = strsep(&datablob, " \t");if (!c)return -EINVAL;key_cmd = match_token(c, key_tokens, args);switch (key_cmd) {case Opt_new:/* first argument is key size */c = strsep(&datablob, " \t");if (!c)return -EINVAL;ret = kstrtol(c, 10, &keylen);if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)return -EINVAL;p->key_len = keylen;ret = Opt_new;break;case Opt_load:/* first argument is sealed blob */c = strsep(&datablob, " \t");if (!c)return -EINVAL;p->blob_len = strlen(c) / 2;if (p->blob_len > MAX_BLOB_SIZE)return -EINVAL;ret = hex2bin(p->blob, c, p->blob_len);if (ret < 0)return -EINVAL;ret = Opt_load;break;case Opt_update:ret = Opt_update;break;case Opt_err:return -EINVAL;}return ret;+}
+static struct trusted_key_payload *trusted_payload_alloc(struct key *key) +{
struct trusted_key_payload *p = NULL;int ret;ret = key_payload_reserve(key, sizeof(*p));if (ret < 0)return p;p = kzalloc(sizeof(*p), GFP_KERNEL);p->migratable = tk_ops->migratable;return p;+}
+/*
- trusted_instantiate - create a new trusted key
- Unseal an existing trusted blob or, for a new key, get a
- random key, then seal and create a trusted key-type key,
- adding it to the specified keyring.
- On success, return 0. Otherwise return errno.
- */
+static int trusted_instantiate(struct key *key,
struct key_preparsed_payload *prep)+{
struct trusted_key_payload *payload = NULL;size_t datalen = prep->datalen;char *datablob;int ret = 0;int key_cmd;size_t key_len;if (datalen <= 0 || datalen > 32767 || !prep->data)return -EINVAL;datablob = kmalloc(datalen + 1, GFP_KERNEL);if (!datablob)return -ENOMEM;memcpy(datablob, prep->data, datalen);datablob[datalen] = '\0';payload = trusted_payload_alloc(key);if (!payload) {ret = -ENOMEM;goto out;}key_cmd = datablob_parse(datablob, payload);if (key_cmd < 0) {ret = key_cmd;goto out;}dump_payload(payload);switch (key_cmd) {case Opt_load:ret = tk_ops->unseal(payload, datablob);dump_payload(payload);if (ret < 0)pr_info("trusted_key: key_unseal failed (%d)\n", ret);break;case Opt_new:key_len = payload->key_len;ret = tk_ops->get_random(payload->key, key_len);if (ret != key_len) {pr_info("trusted_key: key_create failed (%d)\n", ret);goto out;}ret = tk_ops->seal(payload, datablob);if (ret < 0)pr_info("trusted_key: key_seal failed (%d)\n", ret);break;default:ret = -EINVAL;}+out:
kzfree(datablob);if (!ret)rcu_assign_keypointer(key, payload);elsekzfree(payload);return ret;+}
+static void trusted_rcu_free(struct rcu_head *rcu) +{
struct trusted_key_payload *p;p = container_of(rcu, struct trusted_key_payload, rcu);kzfree(p);+}
+/*
- trusted_update - reseal an existing key with new PCR values
- */
+static int trusted_update(struct key *key, struct key_preparsed_payload *prep) +{
struct trusted_key_payload *p;struct trusted_key_payload *new_p;size_t datalen = prep->datalen;char *datablob;int ret = 0;if (key_is_negative(key))return -ENOKEY;p = key->payload.data[0];if (!p->migratable)return -EPERM;if (datalen <= 0 || datalen > 32767 || !prep->data)return -EINVAL;datablob = kmalloc(datalen + 1, GFP_KERNEL);if (!datablob)return -ENOMEM;new_p = trusted_payload_alloc(key);if (!new_p) {ret = -ENOMEM;goto out;}memcpy(datablob, prep->data, datalen);datablob[datalen] = '\0';ret = datablob_parse(datablob, new_p);if (ret != Opt_update) {ret = -EINVAL;kzfree(new_p);goto out;}/* copy old key values, and reseal with new pcrs */new_p->migratable = p->migratable;new_p->key_len = p->key_len;memcpy(new_p->key, p->key, p->key_len);dump_payload(p);dump_payload(new_p);ret = tk_ops->seal(new_p, datablob);if (ret < 0) {pr_info("trusted_key: key_seal failed (%d)\n", ret);kzfree(new_p);goto out;}rcu_assign_keypointer(key, new_p);call_rcu(&p->rcu, trusted_rcu_free);+out:
kzfree(datablob);return ret;+}
+/*
- trusted_read - copy the sealed blob data to userspace in hex.
- On success, return to userspace the trusted key datablob size.
- */
+static long trusted_read(const struct key *key, char *buffer,
size_t buflen)+{
const struct trusted_key_payload *p;char *bufp;int i;p = dereference_key_locked(key);if (!p)return -EINVAL;if (buffer && buflen >= 2 * p->blob_len) {bufp = buffer;for (i = 0; i < p->blob_len; i++)bufp = hex_byte_pack(bufp, p->blob[i]);}return 2 * p->blob_len;+}
+/*
- trusted_destroy - clear and free the key's payload
- */
+static void trusted_destroy(struct key *key) +{
kzfree(key->payload.data[0]);+}
+struct key_type key_type_trusted = {
.name = "trusted",.instantiate = trusted_instantiate,.update = trusted_update,.destroy = trusted_destroy,.describe = user_describe,.read = trusted_read,+}; +EXPORT_SYMBOL_GPL(key_type_trusted);
+static int __init init_trusted(void) +{
int i, ret = 0;for (i = 0; i < sizeof(available_tk_ops); i++) {tk_ops = available_tk_ops[i];if (!(tk_ops && tk_ops->init && tk_ops->seal &&tk_ops->unseal && tk_ops->get_random))continue;ret = tk_ops->init();if (ret) {if (tk_ops->cleanup)tk_ops->cleanup();} else {break;}}/** encrypted_keys.ko depends on successful load of this module even if* trusted key implementation is not found.*/if (ret == -ENODEV)return 0;return ret;+}
+static void __exit cleanup_trusted(void) +{
if (tk_ops->cleanup)tk_ops->cleanup();+}
+late_initcall(init_trusted); +module_exit(cleanup_trusted);
+MODULE_LICENSE("GPL"); diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c index 8001ab0..32fd1ea 100644 --- a/security/keys/trusted-keys/trusted_tpm1.c +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -1,29 +1,26 @@ // SPDX-License-Identifier: GPL-2.0-only /*
- Copyright (C) 2010 IBM Corporation
- Copyright (c) 2019, Linaro Limited
- Author:
- David Safford safford@us.ibm.com
*/
- Switch to generic trusted key framework: Sumit Garg sumit.garg@linaro.org
- See Documentation/security/keys/trusted-encrypted.rst
#include <crypto/hash_info.h> -#include <linux/uaccess.h> -#include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/parser.h> #include <linux/string.h> #include <linux/err.h> -#include <keys/user-type.h> #include <keys/trusted-type.h> #include <linux/key-type.h> -#include <linux/rcupdate.h> #include <linux/crypto.h> #include <crypto/hash.h> #include <crypto/sha.h> -#include <linux/capability.h> #include <linux/tpm.h> #include <linux/tpm_command.h>
@@ -703,7 +700,6 @@ static int key_unseal(struct trusted_key_payload *p,
enum { Opt_err,
Opt_new, Opt_load, Opt_update, Opt_keyhandle, Opt_keyauth, Opt_blobauth, Opt_pcrinfo, Opt_pcrlock, Opt_migratable, Opt_hash,@@ -712,9 +708,6 @@ enum { };
static const match_table_t key_tokens = {
{Opt_new, "new"},{Opt_load, "load"},{Opt_update, "update"}, {Opt_keyhandle, "keyhandle=%s"}, {Opt_keyauth, "keyauth=%s"}, {Opt_blobauth, "blobauth=%s"},@@ -841,71 +834,6 @@ static int getoptions(char *c, struct trusted_key_payload *pay, return 0; }
-/*
- datablob_parse - parse the keyctl data and fill in the
payload and options structures
- On success returns 0, otherwise -EINVAL.
- */
-static int datablob_parse(char *datablob, struct trusted_key_payload *p,
struct trusted_key_options *o)-{
substring_t args[MAX_OPT_ARGS];long keylen;int ret = -EINVAL;int key_cmd;char *c;/* main command */c = strsep(&datablob, " \t");if (!c)return -EINVAL;key_cmd = match_token(c, key_tokens, args);switch (key_cmd) {case Opt_new:/* first argument is key size */c = strsep(&datablob, " \t");if (!c)return -EINVAL;ret = kstrtol(c, 10, &keylen);if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)return -EINVAL;p->key_len = keylen;ret = getoptions(datablob, p, o);if (ret < 0)return ret;ret = Opt_new;break;case Opt_load:/* first argument is sealed blob */c = strsep(&datablob, " \t");if (!c)return -EINVAL;p->blob_len = strlen(c) / 2;if (p->blob_len > MAX_BLOB_SIZE)return -EINVAL;ret = hex2bin(p->blob, c, p->blob_len);if (ret < 0)return -EINVAL;ret = getoptions(datablob, p, o);if (ret < 0)return ret;ret = Opt_load;break;case Opt_update:/* all arguments are options */ret = getoptions(datablob, p, o);if (ret < 0)return ret;ret = Opt_update;break;case Opt_err:return -EINVAL;break;}return ret;-}
static struct trusted_key_options *trusted_options_alloc(void) { struct trusted_key_options *options; @@ -926,248 +854,99 @@ static struct trusted_key_options *trusted_options_alloc(void) return options; }
-static struct trusted_key_payload *trusted_payload_alloc(struct key *key) +static int tpm_tk_seal(struct trusted_key_payload *p, char *datablob) {
struct trusted_key_payload *p = NULL;int ret;ret = key_payload_reserve(key, sizeof *p);if (ret < 0)return p;p = kzalloc(sizeof *p, GFP_KERNEL);if (p)p->migratable = 1; /* migratable by default */return p;-}
-/*
- trusted_instantiate - create a new trusted key
- Unseal an existing trusted blob or, for a new key, get a
- random key, then seal and create a trusted key-type key,
- adding it to the specified keyring.
- On success, return 0. Otherwise return errno.
- */
-static int trusted_instantiate(struct key *key,
struct key_preparsed_payload *prep)-{
struct trusted_key_payload *payload = NULL; struct trusted_key_options *options = NULL;size_t datalen = prep->datalen;char *datablob; int ret = 0;int key_cmd;size_t key_len; int tpm2; tpm2 = tpm_is_tpm2(chip); if (tpm2 < 0) return tpm2;if (datalen <= 0 || datalen > 32767 || !prep->data)return -EINVAL;datablob = kmalloc(datalen + 1, GFP_KERNEL);if (!datablob)return -ENOMEM;memcpy(datablob, prep->data, datalen);datablob[datalen] = '\0';options = trusted_options_alloc();if (!options) {ret = -ENOMEM;goto out;}payload = trusted_payload_alloc(key);if (!payload) {ret = -ENOMEM;goto out;}
if (!options)return -ENOMEM;
key_cmd = datablob_parse(datablob, payload, options);if (key_cmd < 0) {ret = key_cmd;
ret = getoptions(datablob, p, options);if (ret < 0) goto out;
}
dump_options(options); if (!options->keyhandle) { ret = -EINVAL; goto out; }
dump_payload(payload);dump_options(options);
if (tpm2)ret = tpm2_seal_trusted(chip, p, options);elseret = key_seal(p, options);if (ret < 0) {pr_info("tpm_trusted_key: key_seal failed (%d)\n", ret);goto out;}
switch (key_cmd) {case Opt_load:if (tpm2)ret = tpm2_unseal_trusted(chip, payload, options);elseret = key_unseal(payload, options);dump_payload(payload);dump_options(options);if (ret < 0)pr_info("trusted_key: key_unseal failed (%d)\n", ret);break;case Opt_new:key_len = payload->key_len;ret = tpm_get_random(chip, payload->key, key_len);if (ret != key_len) {pr_info("trusted_key: key_create failed (%d)\n", ret);
if (options->pcrlock) {ret = pcrlock(options->pcrlock);if (ret < 0) {pr_info("tpm_trusted_key: pcrlock failed (%d)\n", ret); goto out; }
if (tpm2)ret = tpm2_seal_trusted(chip, payload, options);elseret = key_seal(payload, options);if (ret < 0)pr_info("trusted_key: key_seal failed (%d)\n", ret);break;default:ret = -EINVAL;goto out; }if (!ret && options->pcrlock)ret = pcrlock(options->pcrlock);out:
kzfree(datablob); kzfree(options);if (!ret)rcu_assign_keypointer(key, payload);elsekzfree(payload); return ret;}
-static void trusted_rcu_free(struct rcu_head *rcu) +static int tpm_tk_unseal(struct trusted_key_payload *p, char *datablob) {
struct trusted_key_payload *p;p = container_of(rcu, struct trusted_key_payload, rcu);kzfree(p);-}
-/*
- trusted_update - reseal an existing key with new PCR values
- */
-static int trusted_update(struct key *key, struct key_preparsed_payload *prep) -{
struct trusted_key_payload *p;struct trusted_key_payload *new_p;struct trusted_key_options *new_o;size_t datalen = prep->datalen;char *datablob;
struct trusted_key_options *options = NULL; int ret = 0;int tpm2;
if (key_is_negative(key))return -ENOKEY;p = key->payload.data[0];if (!p->migratable)return -EPERM;if (datalen <= 0 || datalen > 32767 || !prep->data)return -EINVAL;
tpm2 = tpm_is_tpm2(chip);if (tpm2 < 0)return tpm2;
datablob = kmalloc(datalen + 1, GFP_KERNEL);if (!datablob)
options = trusted_options_alloc();if (!options) return -ENOMEM;
new_o = trusted_options_alloc();if (!new_o) {ret = -ENOMEM;goto out;}new_p = trusted_payload_alloc(key);if (!new_p) {ret = -ENOMEM;goto out;}memcpy(datablob, prep->data, datalen);datablob[datalen] = '\0';ret = datablob_parse(datablob, new_p, new_o);if (ret != Opt_update) {ret = -EINVAL;kzfree(new_p);
ret = getoptions(datablob, p, options);if (ret < 0) goto out;
}
dump_options(options);
if (!new_o->keyhandle) {
if (!options->keyhandle) { ret = -EINVAL;
kzfree(new_p); goto out; }/* copy old key values, and reseal with new pcrs */new_p->migratable = p->migratable;new_p->key_len = p->key_len;memcpy(new_p->key, p->key, p->key_len);dump_payload(p);dump_payload(new_p);
if (tpm2)ret = tpm2_unseal_trusted(chip, p, options);elseret = key_unseal(p, options);if (ret < 0)pr_info("tpm_trusted_key: key_unseal failed (%d)\n", ret);
ret = key_seal(new_p, new_o);if (ret < 0) {pr_info("trusted_key: key_seal failed (%d)\n", ret);kzfree(new_p);goto out;}if (new_o->pcrlock) {ret = pcrlock(new_o->pcrlock);
if (options->pcrlock) {ret = pcrlock(options->pcrlock); if (ret < 0) {
pr_info("trusted_key: pcrlock failed (%d)\n", ret);kzfree(new_p);
pr_info("tpm_trusted_key: pcrlock failed (%d)\n", ret); goto out; } }
rcu_assign_keypointer(key, new_p);call_rcu(&p->rcu, trusted_rcu_free);out:
kzfree(datablob);kzfree(new_o);
kzfree(options); return ret;}
-/*
- trusted_read - copy the sealed blob data to userspace in hex.
- On success, return to userspace the trusted key datablob size.
- */
-static long trusted_read(const struct key *key, char *buffer,
size_t buflen)-{
const struct trusted_key_payload *p;char *bufp;int i;p = dereference_key_locked(key);if (!p)return -EINVAL;if (buffer && buflen >= 2 * p->blob_len) {bufp = buffer;for (i = 0; i < p->blob_len; i++)bufp = hex_byte_pack(bufp, p->blob[i]);}return 2 * p->blob_len;-}
-/*
- trusted_destroy - clear and free the key's payload
- */
-static void trusted_destroy(struct key *key) +int tpm_tk_get_random(unsigned char *key, size_t key_len) {
kzfree(key->payload.data[0]);
return tpm_get_random(chip, key, key_len);}
-struct key_type key_type_trusted = {
.name = "trusted",.instantiate = trusted_instantiate,.update = trusted_update,.destroy = trusted_destroy,.describe = user_describe,.read = trusted_read,-};
-EXPORT_SYMBOL_GPL(key_type_trusted);
static void trusted_shash_release(void) { if (hashalg) @@ -1182,14 +961,14 @@ static int __init trusted_shash_alloc(void)
hmacalg = crypto_alloc_shash(hmac_alg, 0, 0); if (IS_ERR(hmacalg)) {
pr_info("trusted_key: could not allocate crypto %s\n",
pr_info("tpm_trusted_key: could not allocate crypto %s\n", hmac_alg); return PTR_ERR(hmacalg); } hashalg = crypto_alloc_shash(hash_alg, 0, 0); if (IS_ERR(hashalg)) {
pr_info("trusted_key: could not allocate crypto %s\n",
pr_info("tpm_trusted_key: could not allocate crypto %s\n", hash_alg); ret = PTR_ERR(hashalg); goto hashalg_fail;@@ -1217,16 +996,13 @@ static int __init init_digests(void) return 0; }
-static int __init init_trusted(void) +static int __init init_tpm_trusted(void) { int ret;
/* encrypted_keys.ko depends on successful load of this module even if* TPM is not used.*/ chip = tpm_default_chip(); if (!chip)return 0;
return -ENODEV; ret = init_digests(); if (ret < 0)@@ -1247,7 +1023,7 @@ static int __init init_trusted(void) return ret; }
-static void __exit cleanup_trusted(void) +static void __exit cleanup_tpm_trusted(void) { if (chip) { put_device(&chip->dev); @@ -1257,7 +1033,12 @@ static void __exit cleanup_trusted(void) } }
-late_initcall(init_trusted); -module_exit(cleanup_trusted);
-MODULE_LICENSE("GPL"); +struct trusted_key_ops tpm_trusted_key_ops = {
.migratable = 1, /* migratable by default */.init = init_tpm_trusted,.seal = tpm_tk_seal,.unseal = tpm_tk_unseal,.get_random = tpm_tk_get_random,.cleanup = cleanup_tpm_trusted,+}; +EXPORT_SYMBOL_GPL(tpm_trusted_key_ops);
Everywhere: do not use 'tk'. Use 'trusted' in those places. We do not want a new acronym.
Okay.
-Sumit
/Jarkko
On Wed, May 06, 2020 at 03:10:14PM +0530, Sumit Garg wrote:
Current trusted keys framework is tightly coupled to use TPM device as an underlying implementation which makes it difficult for implementations like Trusted Execution Environment (TEE) etc. to provide trusked keys support in case platform doesn't posses a TPM device.
So this patch tries to add generic trusted keys framework where underlying implemtations like TPM, TEE etc. could be easily plugged-in.
Suggested-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: Sumit Garg sumit.garg@linaro.org
include/keys/trusted-type.h | 45 ++++ include/keys/trusted_tpm.h | 15 -- security/keys/trusted-keys/Makefile | 1 + security/keys/trusted-keys/trusted_common.c | 333 +++++++++++++++++++++++++++ security/keys/trusted-keys/trusted_tpm1.c | 335 +++++----------------------- 5 files changed, 437 insertions(+), 292 deletions(-) create mode 100644 security/keys/trusted-keys/trusted_common.c
diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h index a94c03a..5559010 100644 --- a/include/keys/trusted-type.h +++ b/include/keys/trusted-type.h @@ -40,6 +40,51 @@ struct trusted_key_options { uint32_t policyhandle; }; +struct trusted_key_ops {
- /*
* flag to indicate if trusted key implementation supports migration* or not.*/- unsigned char migratable;
- /* trusted key init */
- int (*init)(void);
- /* seal a trusted key */
- int (*seal)(struct trusted_key_payload *p, char *datablob);
- /* unseal a trusted key */
- int (*unseal)(struct trusted_key_payload *p, char *datablob);
- /* get random trusted key */
- int (*get_random)(unsigned char *key, size_t key_len);
- /* trusted key cleanup */
- void (*cleanup)(void);
+};
extern struct key_type key_type_trusted; +#if defined(CONFIG_TCG_TPM) +extern struct trusted_key_ops tpm_trusted_key_ops; +#endif
+#define TRUSTED_DEBUG 0
+#if TRUSTED_DEBUG +static inline void dump_payload(struct trusted_key_payload *p) +{
- pr_info("trusted_key: key_len %d\n", p->key_len);
- print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE,
16, 1, p->key, p->key_len, 0);- pr_info("trusted_key: bloblen %d\n", p->blob_len);
- print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE,
16, 1, p->blob, p->blob_len, 0);- pr_info("trusted_key: migratable %d\n", p->migratable);
+} +#else +static inline void dump_payload(struct trusted_key_payload *p) +{ +} +#endif #endif /* _KEYS_TRUSTED_TYPE_H */ diff --git a/include/keys/trusted_tpm.h b/include/keys/trusted_tpm.h index a56d8e1..5753231 100644 --- a/include/keys/trusted_tpm.h +++ b/include/keys/trusted_tpm.h @@ -60,17 +60,6 @@ static inline void dump_options(struct trusted_key_options *o) 16, 1, o->pcrinfo, o->pcrinfo_len, 0); } -static inline void dump_payload(struct trusted_key_payload *p) -{
- pr_info("trusted_key: key_len %d\n", p->key_len);
- print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE,
16, 1, p->key, p->key_len, 0);- pr_info("trusted_key: bloblen %d\n", p->blob_len);
- print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE,
16, 1, p->blob, p->blob_len, 0);- pr_info("trusted_key: migratable %d\n", p->migratable);
-}
static inline void dump_sess(struct osapsess *s) { print_hex_dump(KERN_INFO, "trusted-key: handle ", DUMP_PREFIX_NONE, @@ -96,10 +85,6 @@ static inline void dump_options(struct trusted_key_options *o) { } -static inline void dump_payload(struct trusted_key_payload *p) -{ -}
static inline void dump_sess(struct osapsess *s) { } diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile index 7b73ceb..2b1085b 100644 --- a/security/keys/trusted-keys/Makefile +++ b/security/keys/trusted-keys/Makefile @@ -4,5 +4,6 @@ # obj-$(CONFIG_TRUSTED_KEYS) += trusted.o +trusted-y += trusted_common.o trusted-y += trusted_tpm1.o trusted-y += trusted_tpm2.o diff --git a/security/keys/trusted-keys/trusted_common.c b/security/keys/trusted-keys/trusted_common.c new file mode 100644 index 0000000..9bfd081 --- /dev/null +++ b/security/keys/trusted-keys/trusted_common.c @@ -0,0 +1,333 @@ +// SPDX-License-Identifier: GPL-2.0-only +/*
- Copyright (C) 2010 IBM Corporation
- Copyright (c) 2019, Linaro Limited
- Author:
- David Safford safford@us.ibm.com
- Added generic trusted key framework: Sumit Garg sumit.garg@linaro.org
- See Documentation/security/keys/trusted-encrypted.rst
- */
+#include <keys/user-type.h> +#include <keys/trusted-type.h> +#include <linux/capability.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/key-type.h> +#include <linux/module.h> +#include <linux/parser.h> +#include <linux/rcupdate.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/uaccess.h>
+static struct trusted_key_ops *available_tk_ops[] = { +#if defined(CONFIG_TCG_TPM)
- &tpm_trusted_key_ops,
+#endif +};
This, I think is wrong. You should have a compile time flag for TPM e.g. CONFIG_TRUSTED_TPM, not this dynamic mess.
Please make the whole choice compile time, not run-time.
+static struct trusted_key_ops *tk_ops;
+enum {
- Opt_err,
- Opt_new, Opt_load, Opt_update,
+};
+static const match_table_t key_tokens = {
- {Opt_new, "new"},
- {Opt_load, "load"},
- {Opt_update, "update"},
- {Opt_err, NULL}
+};
+/*
- datablob_parse - parse the keyctl data and fill in the
payload structure
- On success returns 0, otherwise -EINVAL.
- */
+static int datablob_parse(char *datablob, struct trusted_key_payload *p) +{
- substring_t args[MAX_OPT_ARGS];
- long keylen;
- int ret = -EINVAL;
- int key_cmd;
- char *c;
- /* main command */
- c = strsep(&datablob, " \t");
- if (!c)
return -EINVAL;- key_cmd = match_token(c, key_tokens, args);
- switch (key_cmd) {
- case Opt_new:
/* first argument is key size */c = strsep(&datablob, " \t");if (!c)return -EINVAL;ret = kstrtol(c, 10, &keylen);if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)return -EINVAL;p->key_len = keylen;ret = Opt_new;break;- case Opt_load:
/* first argument is sealed blob */c = strsep(&datablob, " \t");if (!c)return -EINVAL;p->blob_len = strlen(c) / 2;if (p->blob_len > MAX_BLOB_SIZE)return -EINVAL;ret = hex2bin(p->blob, c, p->blob_len);if (ret < 0)return -EINVAL;ret = Opt_load;break;- case Opt_update:
ret = Opt_update;break;- case Opt_err:
return -EINVAL;- }
- return ret;
+}
+static struct trusted_key_payload *trusted_payload_alloc(struct key *key) +{
- struct trusted_key_payload *p = NULL;
- int ret;
- ret = key_payload_reserve(key, sizeof(*p));
- if (ret < 0)
return p;- p = kzalloc(sizeof(*p), GFP_KERNEL);
- p->migratable = tk_ops->migratable;
- return p;
+}
+/*
- trusted_instantiate - create a new trusted key
- Unseal an existing trusted blob or, for a new key, get a
- random key, then seal and create a trusted key-type key,
- adding it to the specified keyring.
- On success, return 0. Otherwise return errno.
- */
+static int trusted_instantiate(struct key *key,
struct key_preparsed_payload *prep)+{
- struct trusted_key_payload *payload = NULL;
- size_t datalen = prep->datalen;
- char *datablob;
- int ret = 0;
- int key_cmd;
- size_t key_len;
- if (datalen <= 0 || datalen > 32767 || !prep->data)
return -EINVAL;- datablob = kmalloc(datalen + 1, GFP_KERNEL);
- if (!datablob)
return -ENOMEM;- memcpy(datablob, prep->data, datalen);
- datablob[datalen] = '\0';
- payload = trusted_payload_alloc(key);
- if (!payload) {
ret = -ENOMEM;goto out;- }
- key_cmd = datablob_parse(datablob, payload);
- if (key_cmd < 0) {
ret = key_cmd;goto out;- }
- dump_payload(payload);
- switch (key_cmd) {
- case Opt_load:
ret = tk_ops->unseal(payload, datablob);dump_payload(payload);if (ret < 0)pr_info("trusted_key: key_unseal failed (%d)\n", ret);break;- case Opt_new:
key_len = payload->key_len;ret = tk_ops->get_random(payload->key, key_len);if (ret != key_len) {pr_info("trusted_key: key_create failed (%d)\n", ret);goto out;}ret = tk_ops->seal(payload, datablob);if (ret < 0)pr_info("trusted_key: key_seal failed (%d)\n", ret);break;- default:
ret = -EINVAL;- }
+out:
- kzfree(datablob);
- if (!ret)
rcu_assign_keypointer(key, payload);- else
kzfree(payload);- return ret;
+}
+static void trusted_rcu_free(struct rcu_head *rcu) +{
- struct trusted_key_payload *p;
- p = container_of(rcu, struct trusted_key_payload, rcu);
- kzfree(p);
+}
+/*
- trusted_update - reseal an existing key with new PCR values
- */
+static int trusted_update(struct key *key, struct key_preparsed_payload *prep) +{
- struct trusted_key_payload *p;
- struct trusted_key_payload *new_p;
- size_t datalen = prep->datalen;
- char *datablob;
- int ret = 0;
- if (key_is_negative(key))
return -ENOKEY;- p = key->payload.data[0];
- if (!p->migratable)
return -EPERM;- if (datalen <= 0 || datalen > 32767 || !prep->data)
return -EINVAL;- datablob = kmalloc(datalen + 1, GFP_KERNEL);
- if (!datablob)
return -ENOMEM;- new_p = trusted_payload_alloc(key);
- if (!new_p) {
ret = -ENOMEM;goto out;- }
- memcpy(datablob, prep->data, datalen);
- datablob[datalen] = '\0';
- ret = datablob_parse(datablob, new_p);
- if (ret != Opt_update) {
ret = -EINVAL;kzfree(new_p);goto out;- }
- /* copy old key values, and reseal with new pcrs */
- new_p->migratable = p->migratable;
- new_p->key_len = p->key_len;
- memcpy(new_p->key, p->key, p->key_len);
- dump_payload(p);
- dump_payload(new_p);
- ret = tk_ops->seal(new_p, datablob);
- if (ret < 0) {
pr_info("trusted_key: key_seal failed (%d)\n", ret);kzfree(new_p);goto out;- }
- rcu_assign_keypointer(key, new_p);
- call_rcu(&p->rcu, trusted_rcu_free);
+out:
- kzfree(datablob);
- return ret;
+}
+/*
- trusted_read - copy the sealed blob data to userspace in hex.
- On success, return to userspace the trusted key datablob size.
- */
+static long trusted_read(const struct key *key, char *buffer,
size_t buflen)+{
- const struct trusted_key_payload *p;
- char *bufp;
- int i;
- p = dereference_key_locked(key);
- if (!p)
return -EINVAL;- if (buffer && buflen >= 2 * p->blob_len) {
bufp = buffer;for (i = 0; i < p->blob_len; i++)bufp = hex_byte_pack(bufp, p->blob[i]);- }
- return 2 * p->blob_len;
+}
+/*
- trusted_destroy - clear and free the key's payload
- */
+static void trusted_destroy(struct key *key) +{
- kzfree(key->payload.data[0]);
+}
+struct key_type key_type_trusted = {
- .name = "trusted",
- .instantiate = trusted_instantiate,
- .update = trusted_update,
- .destroy = trusted_destroy,
- .describe = user_describe,
- .read = trusted_read,
+}; +EXPORT_SYMBOL_GPL(key_type_trusted);
+static int __init init_trusted(void) +{
- int i, ret = 0;
- for (i = 0; i < sizeof(available_tk_ops); i++) {
tk_ops = available_tk_ops[i];if (!(tk_ops && tk_ops->init && tk_ops->seal &&tk_ops->unseal && tk_ops->get_random))continue;
This check should not exist as there is no legit case for any of these callbacks missing. Please remove it.
ret = tk_ops->init();if (ret) {if (tk_ops->cleanup)tk_ops->cleanup();
Why is clean up called? What is "clean up"? Init should take care clean up its dirt if it fails. Please remove the calll to clean up from here.
/Jarkko
On Mon, 1 Jun 2020 at 07:41, Jarkko Sakkinen jarkko.sakkinen@linux.intel.com wrote:
On Wed, May 06, 2020 at 03:10:14PM +0530, Sumit Garg wrote:
Current trusted keys framework is tightly coupled to use TPM device as an underlying implementation which makes it difficult for implementations like Trusted Execution Environment (TEE) etc. to provide trusked keys support in case platform doesn't posses a TPM device.
So this patch tries to add generic trusted keys framework where underlying implemtations like TPM, TEE etc. could be easily plugged-in.
Suggested-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: Sumit Garg sumit.garg@linaro.org
include/keys/trusted-type.h | 45 ++++ include/keys/trusted_tpm.h | 15 -- security/keys/trusted-keys/Makefile | 1 + security/keys/trusted-keys/trusted_common.c | 333 +++++++++++++++++++++++++++ security/keys/trusted-keys/trusted_tpm1.c | 335 +++++----------------------- 5 files changed, 437 insertions(+), 292 deletions(-) create mode 100644 security/keys/trusted-keys/trusted_common.c
diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h index a94c03a..5559010 100644 --- a/include/keys/trusted-type.h +++ b/include/keys/trusted-type.h @@ -40,6 +40,51 @@ struct trusted_key_options { uint32_t policyhandle; };
+struct trusted_key_ops {
/** flag to indicate if trusted key implementation supports migration* or not.*/unsigned char migratable;/* trusted key init */int (*init)(void);/* seal a trusted key */int (*seal)(struct trusted_key_payload *p, char *datablob);/* unseal a trusted key */int (*unseal)(struct trusted_key_payload *p, char *datablob);/* get random trusted key */int (*get_random)(unsigned char *key, size_t key_len);/* trusted key cleanup */void (*cleanup)(void);+};
extern struct key_type key_type_trusted; +#if defined(CONFIG_TCG_TPM) +extern struct trusted_key_ops tpm_trusted_key_ops; +#endif
+#define TRUSTED_DEBUG 0
+#if TRUSTED_DEBUG +static inline void dump_payload(struct trusted_key_payload *p) +{
pr_info("trusted_key: key_len %d\n", p->key_len);print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE,16, 1, p->key, p->key_len, 0);pr_info("trusted_key: bloblen %d\n", p->blob_len);print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE,16, 1, p->blob, p->blob_len, 0);pr_info("trusted_key: migratable %d\n", p->migratable);+} +#else +static inline void dump_payload(struct trusted_key_payload *p) +{ +} +#endif
#endif /* _KEYS_TRUSTED_TYPE_H */ diff --git a/include/keys/trusted_tpm.h b/include/keys/trusted_tpm.h index a56d8e1..5753231 100644 --- a/include/keys/trusted_tpm.h +++ b/include/keys/trusted_tpm.h @@ -60,17 +60,6 @@ static inline void dump_options(struct trusted_key_options *o) 16, 1, o->pcrinfo, o->pcrinfo_len, 0); }
-static inline void dump_payload(struct trusted_key_payload *p) -{
pr_info("trusted_key: key_len %d\n", p->key_len);print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE,16, 1, p->key, p->key_len, 0);pr_info("trusted_key: bloblen %d\n", p->blob_len);print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE,16, 1, p->blob, p->blob_len, 0);pr_info("trusted_key: migratable %d\n", p->migratable);-}
static inline void dump_sess(struct osapsess *s) { print_hex_dump(KERN_INFO, "trusted-key: handle ", DUMP_PREFIX_NONE, @@ -96,10 +85,6 @@ static inline void dump_options(struct trusted_key_options *o) { }
-static inline void dump_payload(struct trusted_key_payload *p) -{ -}
static inline void dump_sess(struct osapsess *s) { } diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile index 7b73ceb..2b1085b 100644 --- a/security/keys/trusted-keys/Makefile +++ b/security/keys/trusted-keys/Makefile @@ -4,5 +4,6 @@ #
obj-$(CONFIG_TRUSTED_KEYS) += trusted.o +trusted-y += trusted_common.o trusted-y += trusted_tpm1.o trusted-y += trusted_tpm2.o diff --git a/security/keys/trusted-keys/trusted_common.c b/security/keys/trusted-keys/trusted_common.c new file mode 100644 index 0000000..9bfd081 --- /dev/null +++ b/security/keys/trusted-keys/trusted_common.c @@ -0,0 +1,333 @@ +// SPDX-License-Identifier: GPL-2.0-only +/*
- Copyright (C) 2010 IBM Corporation
- Copyright (c) 2019, Linaro Limited
- Author:
- David Safford safford@us.ibm.com
- Added generic trusted key framework: Sumit Garg sumit.garg@linaro.org
- See Documentation/security/keys/trusted-encrypted.rst
- */
+#include <keys/user-type.h> +#include <keys/trusted-type.h> +#include <linux/capability.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/key-type.h> +#include <linux/module.h> +#include <linux/parser.h> +#include <linux/rcupdate.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/uaccess.h>
+static struct trusted_key_ops *available_tk_ops[] = { +#if defined(CONFIG_TCG_TPM)
&tpm_trusted_key_ops,+#endif +};
This, I think is wrong. You should have a compile time flag for TPM e.g. CONFIG_TRUSTED_TPM, not this dynamic mess.
The whole idea to have it dynamic was to have a common trusted keys module which could support both TPM and TEE implementation depending on hardware. I guess it may be useful in scenarios where a particular hardware supports a TPM chip while other doesn't but both need to run a common kernel image.
Please make the whole choice compile time, not run-time.
+static struct trusted_key_ops *tk_ops;
+enum {
Opt_err,Opt_new, Opt_load, Opt_update,+};
+static const match_table_t key_tokens = {
{Opt_new, "new"},{Opt_load, "load"},{Opt_update, "update"},{Opt_err, NULL}+};
+/*
- datablob_parse - parse the keyctl data and fill in the
payload structure
- On success returns 0, otherwise -EINVAL.
- */
+static int datablob_parse(char *datablob, struct trusted_key_payload *p) +{
substring_t args[MAX_OPT_ARGS];long keylen;int ret = -EINVAL;int key_cmd;char *c;/* main command */c = strsep(&datablob, " \t");if (!c)return -EINVAL;key_cmd = match_token(c, key_tokens, args);switch (key_cmd) {case Opt_new:/* first argument is key size */c = strsep(&datablob, " \t");if (!c)return -EINVAL;ret = kstrtol(c, 10, &keylen);if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)return -EINVAL;p->key_len = keylen;ret = Opt_new;break;case Opt_load:/* first argument is sealed blob */c = strsep(&datablob, " \t");if (!c)return -EINVAL;p->blob_len = strlen(c) / 2;if (p->blob_len > MAX_BLOB_SIZE)return -EINVAL;ret = hex2bin(p->blob, c, p->blob_len);if (ret < 0)return -EINVAL;ret = Opt_load;break;case Opt_update:ret = Opt_update;break;case Opt_err:return -EINVAL;}return ret;+}
+static struct trusted_key_payload *trusted_payload_alloc(struct key *key) +{
struct trusted_key_payload *p = NULL;int ret;ret = key_payload_reserve(key, sizeof(*p));if (ret < 0)return p;p = kzalloc(sizeof(*p), GFP_KERNEL);p->migratable = tk_ops->migratable;return p;+}
+/*
- trusted_instantiate - create a new trusted key
- Unseal an existing trusted blob or, for a new key, get a
- random key, then seal and create a trusted key-type key,
- adding it to the specified keyring.
- On success, return 0. Otherwise return errno.
- */
+static int trusted_instantiate(struct key *key,
struct key_preparsed_payload *prep)+{
struct trusted_key_payload *payload = NULL;size_t datalen = prep->datalen;char *datablob;int ret = 0;int key_cmd;size_t key_len;if (datalen <= 0 || datalen > 32767 || !prep->data)return -EINVAL;datablob = kmalloc(datalen + 1, GFP_KERNEL);if (!datablob)return -ENOMEM;memcpy(datablob, prep->data, datalen);datablob[datalen] = '\0';payload = trusted_payload_alloc(key);if (!payload) {ret = -ENOMEM;goto out;}key_cmd = datablob_parse(datablob, payload);if (key_cmd < 0) {ret = key_cmd;goto out;}dump_payload(payload);switch (key_cmd) {case Opt_load:ret = tk_ops->unseal(payload, datablob);dump_payload(payload);if (ret < 0)pr_info("trusted_key: key_unseal failed (%d)\n", ret);break;case Opt_new:key_len = payload->key_len;ret = tk_ops->get_random(payload->key, key_len);if (ret != key_len) {pr_info("trusted_key: key_create failed (%d)\n", ret);goto out;}ret = tk_ops->seal(payload, datablob);if (ret < 0)pr_info("trusted_key: key_seal failed (%d)\n", ret);break;default:ret = -EINVAL;}+out:
kzfree(datablob);if (!ret)rcu_assign_keypointer(key, payload);elsekzfree(payload);return ret;+}
+static void trusted_rcu_free(struct rcu_head *rcu) +{
struct trusted_key_payload *p;p = container_of(rcu, struct trusted_key_payload, rcu);kzfree(p);+}
+/*
- trusted_update - reseal an existing key with new PCR values
- */
+static int trusted_update(struct key *key, struct key_preparsed_payload *prep) +{
struct trusted_key_payload *p;struct trusted_key_payload *new_p;size_t datalen = prep->datalen;char *datablob;int ret = 0;if (key_is_negative(key))return -ENOKEY;p = key->payload.data[0];if (!p->migratable)return -EPERM;if (datalen <= 0 || datalen > 32767 || !prep->data)return -EINVAL;datablob = kmalloc(datalen + 1, GFP_KERNEL);if (!datablob)return -ENOMEM;new_p = trusted_payload_alloc(key);if (!new_p) {ret = -ENOMEM;goto out;}memcpy(datablob, prep->data, datalen);datablob[datalen] = '\0';ret = datablob_parse(datablob, new_p);if (ret != Opt_update) {ret = -EINVAL;kzfree(new_p);goto out;}/* copy old key values, and reseal with new pcrs */new_p->migratable = p->migratable;new_p->key_len = p->key_len;memcpy(new_p->key, p->key, p->key_len);dump_payload(p);dump_payload(new_p);ret = tk_ops->seal(new_p, datablob);if (ret < 0) {pr_info("trusted_key: key_seal failed (%d)\n", ret);kzfree(new_p);goto out;}rcu_assign_keypointer(key, new_p);call_rcu(&p->rcu, trusted_rcu_free);+out:
kzfree(datablob);return ret;+}
+/*
- trusted_read - copy the sealed blob data to userspace in hex.
- On success, return to userspace the trusted key datablob size.
- */
+static long trusted_read(const struct key *key, char *buffer,
size_t buflen)+{
const struct trusted_key_payload *p;char *bufp;int i;p = dereference_key_locked(key);if (!p)return -EINVAL;if (buffer && buflen >= 2 * p->blob_len) {bufp = buffer;for (i = 0; i < p->blob_len; i++)bufp = hex_byte_pack(bufp, p->blob[i]);}return 2 * p->blob_len;+}
+/*
- trusted_destroy - clear and free the key's payload
- */
+static void trusted_destroy(struct key *key) +{
kzfree(key->payload.data[0]);+}
+struct key_type key_type_trusted = {
.name = "trusted",.instantiate = trusted_instantiate,.update = trusted_update,.destroy = trusted_destroy,.describe = user_describe,.read = trusted_read,+}; +EXPORT_SYMBOL_GPL(key_type_trusted);
+static int __init init_trusted(void) +{
int i, ret = 0;for (i = 0; i < sizeof(available_tk_ops); i++) {tk_ops = available_tk_ops[i];if (!(tk_ops && tk_ops->init && tk_ops->seal &&tk_ops->unseal && tk_ops->get_random))continue;This check should not exist as there is no legit case for any of these callbacks missing. Please remove it.
Okay.
ret = tk_ops->init();if (ret) {if (tk_ops->cleanup)tk_ops->cleanup();Why is clean up called? What is "clean up"? Init should take care clean up its dirt if it fails. Please remove the calll to clean up from here.
Makes sense, will remove it.
-Sumit
/Jarkko
On Mon, Jun 01, 2020 at 02:41:55PM +0530, Sumit Garg wrote:
This, I think is wrong. You should have a compile time flag for TPM e.g. CONFIG_TRUSTED_TPM, not this dynamic mess.
The whole idea to have it dynamic was to have a common trusted keys module which could support both TPM and TEE implementation depending on hardware. I guess it may be useful in scenarios where a particular hardware supports a TPM chip while other doesn't but both need to run a common kernel image.
For now it should only scale to what is needed. No problems refining it later when there is something to enable.
/Jarkko
On Tue, 2 Jun 2020 at 12:44, Jarkko Sakkinen jarkko.sakkinen@linux.intel.com wrote:
On Mon, Jun 01, 2020 at 02:41:55PM +0530, Sumit Garg wrote:
This, I think is wrong. You should have a compile time flag for TPM e.g. CONFIG_TRUSTED_TPM, not this dynamic mess.
The whole idea to have it dynamic was to have a common trusted keys module which could support both TPM and TEE implementation depending on hardware. I guess it may be useful in scenarios where a particular hardware supports a TPM chip while other doesn't but both need to run a common kernel image.
For now it should only scale to what is needed. No problems refining it later when there is something to enable.
Fair enough, will switch to compile time mode then.
-Sumit
/Jarkko
Add support for TEE based trusted keys where TEE provides the functionality to seal and unseal trusted keys using hardware unique key.
Refer to Documentation/tee.txt for detailed information about TEE.
Signed-off-by: Sumit Garg sumit.garg@linaro.org --- include/keys/trusted-type.h | 3 + include/keys/trusted_tee.h | 66 +++++++ security/keys/Kconfig | 3 + security/keys/trusted-keys/Makefile | 1 + security/keys/trusted-keys/trusted_common.c | 3 + security/keys/trusted-keys/trusted_tee.c | 282 ++++++++++++++++++++++++++++ 6 files changed, 358 insertions(+) create mode 100644 include/keys/trusted_tee.h create mode 100644 security/keys/trusted-keys/trusted_tee.c
diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h index 5559010..e0df5df 100644 --- a/include/keys/trusted-type.h +++ b/include/keys/trusted-type.h @@ -67,6 +67,9 @@ extern struct key_type key_type_trusted; #if defined(CONFIG_TCG_TPM) extern struct trusted_key_ops tpm_trusted_key_ops; #endif +#if defined(CONFIG_TEE) +extern struct trusted_key_ops tee_trusted_key_ops; +#endif
#define TRUSTED_DEBUG 0
diff --git a/include/keys/trusted_tee.h b/include/keys/trusted_tee.h new file mode 100644 index 0000000..ab58ffd --- /dev/null +++ b/include/keys/trusted_tee.h @@ -0,0 +1,66 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2019 Linaro Ltd. + * + * Author: + * Sumit Garg sumit.garg@linaro.org + */ + +#ifndef __TEE_TRUSTED_KEY_H +#define __TEE_TRUSTED_KEY_H + +#include <linux/tee_drv.h> + +#define DRIVER_NAME "tee-trusted-key" + +/* + * Get random data for symmetric key + * + * [out] memref[0] Random data + * + * Result: + * TEE_SUCCESS - Invoke command success + * TEE_ERROR_BAD_PARAMETERS - Incorrect input param + */ +#define TA_CMD_GET_RANDOM 0x0 + +/* + * Seal trusted key using hardware unique key + * + * [in] memref[0] Plain key + * [out] memref[1] Sealed key datablob + * + * Result: + * TEE_SUCCESS - Invoke command success + * TEE_ERROR_BAD_PARAMETERS - Incorrect input param + */ +#define TA_CMD_SEAL 0x1 + +/* + * Unseal trusted key using hardware unique key + * + * [in] memref[0] Sealed key datablob + * [out] memref[1] Plain key + * + * Result: + * TEE_SUCCESS - Invoke command success + * TEE_ERROR_BAD_PARAMETERS - Incorrect input param + */ +#define TA_CMD_UNSEAL 0x2 + +/** + * struct trusted_key_private - TEE Trusted key private data + * @dev: TEE based Trusted key device. + * @ctx: TEE context handler. + * @session_id: Trusted key TA session identifier. + * @shm_pool: Memory pool shared with TEE device. + */ +struct trusted_key_private { + struct device *dev; + struct tee_context *ctx; + u32 session_id; + u32 data_rate; + struct tee_shm *shm_pool; +}; + +#endif diff --git a/security/keys/Kconfig b/security/keys/Kconfig index 47c0415..6ca6bc7 100644 --- a/security/keys/Kconfig +++ b/security/keys/Kconfig @@ -84,6 +84,9 @@ config TRUSTED_KEYS if the boot PCRs and other criteria match. Userspace will only ever see encrypted blobs.
+ It also provides support for alternative TEE based Trusted keys + generation and sealing in case TPM isn't present. + If you are unsure as to whether this is required, answer N.
config ENCRYPTED_KEYS diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile index 2b1085b..ea937d3 100644 --- a/security/keys/trusted-keys/Makefile +++ b/security/keys/trusted-keys/Makefile @@ -7,3 +7,4 @@ obj-$(CONFIG_TRUSTED_KEYS) += trusted.o trusted-y += trusted_common.o trusted-y += trusted_tpm1.o trusted-y += trusted_tpm2.o +trusted-y += trusted_tee.o diff --git a/security/keys/trusted-keys/trusted_common.c b/security/keys/trusted-keys/trusted_common.c index 9bfd081..03555ed 100644 --- a/security/keys/trusted-keys/trusted_common.c +++ b/security/keys/trusted-keys/trusted_common.c @@ -27,6 +27,9 @@ static struct trusted_key_ops *available_tk_ops[] = { #if defined(CONFIG_TCG_TPM) &tpm_trusted_key_ops, #endif +#if defined(CONFIG_TEE) + &tee_trusted_key_ops, +#endif }; static struct trusted_key_ops *tk_ops;
diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c new file mode 100644 index 0000000..724a73c --- /dev/null +++ b/security/keys/trusted-keys/trusted_tee.c @@ -0,0 +1,282 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 Linaro Ltd. + * + * Author: + * Sumit Garg sumit.garg@linaro.org + */ + +#include <linux/err.h> +#include <linux/key-type.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/uuid.h> + +#include <keys/trusted-type.h> +#include <keys/trusted_tee.h> + +static struct trusted_key_private pvt_data; + +/* + * Have the TEE seal(encrypt) the symmetric key + */ +static int tee_key_seal(struct trusted_key_payload *p, char *datablob) +{ + int ret = 0; + struct tee_ioctl_invoke_arg inv_arg; + struct tee_param param[4]; + struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL; + + memset(&inv_arg, 0, sizeof(inv_arg)); + memset(¶m, 0, sizeof(param)); + + reg_shm_in = tee_shm_register(pvt_data.ctx, (unsigned long)p->key, + p->key_len, TEE_SHM_DMA_BUF | + TEE_SHM_KERNEL_MAPPED); + if (IS_ERR(reg_shm_in)) { + dev_err(pvt_data.dev, "key shm register failed\n"); + return PTR_ERR(reg_shm_in); + } + + reg_shm_out = tee_shm_register(pvt_data.ctx, (unsigned long)p->blob, + sizeof(p->blob), TEE_SHM_DMA_BUF | + TEE_SHM_KERNEL_MAPPED); + if (IS_ERR(reg_shm_out)) { + dev_err(pvt_data.dev, "blob shm register failed\n"); + ret = PTR_ERR(reg_shm_out); + goto out; + } + + inv_arg.func = TA_CMD_SEAL; + inv_arg.session = pvt_data.session_id; + inv_arg.num_params = 4; + + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT; + param[0].u.memref.shm = reg_shm_in; + param[0].u.memref.size = p->key_len; + param[0].u.memref.shm_offs = 0; + param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT; + param[1].u.memref.shm = reg_shm_out; + param[1].u.memref.size = sizeof(p->blob); + param[1].u.memref.shm_offs = 0; + + ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param); + if ((ret < 0) || (inv_arg.ret != 0)) { + dev_err(pvt_data.dev, "TA_CMD_SEAL invoke err: %x\n", + inv_arg.ret); + ret = -EFAULT; + } else { + p->blob_len = param[1].u.memref.size; + } + +out: + if (reg_shm_out) + tee_shm_free(reg_shm_out); + if (reg_shm_in) + tee_shm_free(reg_shm_in); + + return ret; +} + +/* + * Have the TEE unseal(decrypt) the symmetric key + */ +static int tee_key_unseal(struct trusted_key_payload *p, char *datablob) +{ + int ret = 0; + struct tee_ioctl_invoke_arg inv_arg; + struct tee_param param[4]; + struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL; + + memset(&inv_arg, 0, sizeof(inv_arg)); + memset(¶m, 0, sizeof(param)); + + reg_shm_in = tee_shm_register(pvt_data.ctx, (unsigned long)p->blob, + p->blob_len, TEE_SHM_DMA_BUF | + TEE_SHM_KERNEL_MAPPED); + if (IS_ERR(reg_shm_in)) { + dev_err(pvt_data.dev, "blob shm register failed\n"); + return PTR_ERR(reg_shm_in); + } + + reg_shm_out = tee_shm_register(pvt_data.ctx, (unsigned long)p->key, + sizeof(p->key), TEE_SHM_DMA_BUF | + TEE_SHM_KERNEL_MAPPED); + if (IS_ERR(reg_shm_out)) { + dev_err(pvt_data.dev, "key shm register failed\n"); + ret = PTR_ERR(reg_shm_out); + goto out; + } + + inv_arg.func = TA_CMD_UNSEAL; + inv_arg.session = pvt_data.session_id; + inv_arg.num_params = 4; + + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT; + param[0].u.memref.shm = reg_shm_in; + param[0].u.memref.size = p->blob_len; + param[0].u.memref.shm_offs = 0; + param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT; + param[1].u.memref.shm = reg_shm_out; + param[1].u.memref.size = sizeof(p->key); + param[1].u.memref.shm_offs = 0; + + ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param); + if ((ret < 0) || (inv_arg.ret != 0)) { + dev_err(pvt_data.dev, "TA_CMD_UNSEAL invoke err: %x\n", + inv_arg.ret); + ret = -EFAULT; + } else { + p->key_len = param[1].u.memref.size; + } + +out: + if (reg_shm_out) + tee_shm_free(reg_shm_out); + if (reg_shm_in) + tee_shm_free(reg_shm_in); + + return ret; +} + +/* + * Have the TEE generate random symmetric key + */ +static int tee_get_random(unsigned char *key, size_t key_len) +{ + int ret = 0; + struct tee_ioctl_invoke_arg inv_arg; + struct tee_param param[4]; + struct tee_shm *reg_shm = NULL; + + memset(&inv_arg, 0, sizeof(inv_arg)); + memset(¶m, 0, sizeof(param)); + + reg_shm = tee_shm_register(pvt_data.ctx, (unsigned long)key, key_len, + TEE_SHM_DMA_BUF | TEE_SHM_KERNEL_MAPPED); + if (IS_ERR(reg_shm)) { + dev_err(pvt_data.dev, "random key shm register failed\n"); + return PTR_ERR(reg_shm); + } + + inv_arg.func = TA_CMD_GET_RANDOM; + inv_arg.session = pvt_data.session_id; + inv_arg.num_params = 4; + + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT; + param[0].u.memref.shm = reg_shm; + param[0].u.memref.size = key_len; + param[0].u.memref.shm_offs = 0; + + ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param); + if ((ret < 0) || (inv_arg.ret != 0)) { + dev_err(pvt_data.dev, "TA_CMD_GET_RANDOM invoke err: %x\n", + inv_arg.ret); + ret = -EFAULT; + } else { + ret = param[0].u.memref.size; + } + + tee_shm_free(reg_shm); + + return ret; +} + +static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data) +{ + if (ver->impl_id == TEE_IMPL_ID_OPTEE) + return 1; + else + return 0; +} + +static int trusted_key_probe(struct device *dev) +{ + struct tee_client_device *rng_device = to_tee_client_device(dev); + int ret = 0, err = -ENODEV; + struct tee_ioctl_open_session_arg sess_arg; + + memset(&sess_arg, 0, sizeof(sess_arg)); + + /* Open context with TEE driver */ + pvt_data.ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, + NULL); + if (IS_ERR(pvt_data.ctx)) + return -ENODEV; + + /* Open session with hwrng Trusted App */ + memcpy(sess_arg.uuid, rng_device->id.uuid.b, TEE_IOCTL_UUID_LEN); + sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL; + sess_arg.num_params = 0; + + ret = tee_client_open_session(pvt_data.ctx, &sess_arg, NULL); + if ((ret < 0) || (sess_arg.ret != 0)) { + dev_err(dev, "tee_client_open_session failed, err: %x\n", + sess_arg.ret); + err = -EINVAL; + goto out_ctx; + } + pvt_data.session_id = sess_arg.session; + + ret = register_key_type(&key_type_trusted); + if (ret < 0) + goto out_sess; + + pvt_data.dev = dev; + + return 0; + +out_sess: + tee_client_close_session(pvt_data.ctx, pvt_data.session_id); +out_ctx: + tee_client_close_context(pvt_data.ctx); + + return err; +} + +static int trusted_key_remove(struct device *dev) +{ + unregister_key_type(&key_type_trusted); + tee_client_close_session(pvt_data.ctx, pvt_data.session_id); + tee_client_close_context(pvt_data.ctx); + + return 0; +} + +static const struct tee_client_device_id trusted_key_id_table[] = { + {UUID_INIT(0xf04a0fe7, 0x1f5d, 0x4b9b, + 0xab, 0xf7, 0x61, 0x9b, 0x85, 0xb4, 0xce, 0x8c)}, + {} +}; + +MODULE_DEVICE_TABLE(tee, trusted_key_id_table); + +static struct tee_client_driver trusted_key_driver = { + .id_table = trusted_key_id_table, + .driver = { + .name = DRIVER_NAME, + .bus = &tee_bus_type, + .probe = trusted_key_probe, + .remove = trusted_key_remove, + }, +}; + +static int __init init_tee_trusted(void) +{ + return driver_register(&trusted_key_driver.driver); +} + +static void __exit cleanup_tee_trusted(void) +{ + driver_unregister(&trusted_key_driver.driver); +} + +struct trusted_key_ops tee_trusted_key_ops = { + .migratable = 0, /* non-migratable */ + .init = init_tee_trusted, + .seal = tee_key_seal, + .unseal = tee_key_unseal, + .get_random = tee_get_random, + .cleanup = cleanup_tee_trusted, +}; +EXPORT_SYMBOL_GPL(tee_trusted_key_ops);
On Wed, 2020-05-06 at 15:10 +0530, Sumit Garg wrote:
Add support for TEE based trusted keys where TEE provides the functionality to seal and unseal trusted keys using hardware unique key.
Refer to Documentation/tee.txt for detailed information about TEE.
Signed-off-by: Sumit Garg sumit.garg@linaro.org
The implementation looks solid but how or who could possibly test this?
I do posses (personally, not from employer) bunch of ARM boards but my TZ knowledge is somewhat limited (e.g. how can I get something running in TZ).
/Jarkko
On Thu, 14 May 2020 at 05:58, Jarkko Sakkinen jarkko.sakkinen@linux.intel.com wrote:
On Wed, 2020-05-06 at 15:10 +0530, Sumit Garg wrote:
Add support for TEE based trusted keys where TEE provides the functionality to seal and unseal trusted keys using hardware unique key.
Refer to Documentation/tee.txt for detailed information about TEE.
Signed-off-by: Sumit Garg sumit.garg@linaro.org
The implementation looks solid but how or who could possibly test this?
I do posses (personally, not from employer) bunch of ARM boards but my TZ knowledge is somewhat limited (e.g. how can I get something running in TZ).
Although, it should be fairly easy to test this implementation on an ARM board which supports OP-TEE. But since you are new to ARM TrustZone world, I would suggest you get used to OP-TEE on Qemu based setup. You could find pretty good documentation for this here [1] but for simplicity let me document steps here to test this trusted keys feature from scratch:
# Install prerequisites as mentioned here [2]
# Get the source code $ mkdir -p <optee-project> $ cd <optee-project> $ repo init -u https://github.com/OP-TEE/manifest.git -m qemu_v8.xml $ repo sync -j4 --no-clone-bundle
# Get the toolchain $ cd <optee-project>/build $ make -j2 toolchains
# As trusted keys work is based on latest tpmdd/master, so we can change Linux base as follows: $ cd <optee-project>/linux $ git remote add tpmdd git://git.infradead.org/users/jjs/linux-tpmdd.git $ git pull tpmdd $ git checkout -b tpmdd-master remotes/tpmdd/master # Cherry-pick and apply TEE features patch-set from this PR[3] # Apply this Linux trusted keys patch-set.
# Now move on to build the source code $ cd <optee-project>/build # Apply attached "keyctl_change" patch $ patch -p1 < keyctl_change $ make -j`nproc` CFG_IN_TREE_EARLY_TAS=trusted_keys/f04a0fe7-1f5d-4b9b-abf7-619b85b4ce8c
# Run QEMU setup $ make run-only # Type "c" on QEMU console to continue boot
# Now there should be two virtual consoles up, one for OP-TEE and other for Linux # On Linux console, you can play with "keyctl" utility to have trusted and encrypted keys based on TEE.
Do let me know in case you are stuck while following the above steps.
[1] https://optee.readthedocs.io/en/latest/building/devices/qemu.html#qemu-v8 [2] https://optee.readthedocs.io/en/latest/building/prerequisites.html#prerequis... [3] https://lkml.org/lkml/2020/5/4/1062
-Sumit
/Jarkko
On Thu, 2020-05-14 at 12:57 +0530, Sumit Garg wrote:
On Thu, 14 May 2020 at 05:58, Jarkko Sakkinen jarkko.sakkinen@linux.intel.com wrote:
On Wed, 2020-05-06 at 15:10 +0530, Sumit Garg wrote:
Add support for TEE based trusted keys where TEE provides the functionality to seal and unseal trusted keys using hardware unique key.
Refer to Documentation/tee.txt for detailed information about TEE.
Signed-off-by: Sumit Garg sumit.garg@linaro.org
The implementation looks solid but how or who could possibly test this?
I do posses (personally, not from employer) bunch of ARM boards but my TZ knowledge is somewhat limited (e.g. how can I get something running in TZ).
Although, it should be fairly easy to test this implementation on an ARM board which supports OP-TEE. But since you are new to ARM TrustZone world, I would suggest you get used to OP-TEE on Qemu based setup. You could find pretty good documentation for this here [1] but for simplicity let me document steps here to test this trusted keys feature from scratch:
# Install prerequisites as mentioned here [2]
# Get the source code $ mkdir -p <optee-project> $ cd <optee-project> $ repo init -u https://github.com/OP-TEE/manifest.git -m qemu_v8.xml $ repo sync -j4 --no-clone-bundle
# Get the toolchain $ cd <optee-project>/build $ make -j2 toolchains
# As trusted keys work is based on latest tpmdd/master, so we can change Linux base as follows: $ cd <optee-project>/linux $ git remote add tpmdd git://git.infradead.org/users/jjs/linux-tpmdd.git $ git pull tpmdd $ git checkout -b tpmdd-master remotes/tpmdd/master # Cherry-pick and apply TEE features patch-set from this PR[3] # Apply this Linux trusted keys patch-set.
# Now move on to build the source code $ cd <optee-project>/build # Apply attached "keyctl_change" patch $ patch -p1 < keyctl_change $ make -j`nproc` CFG_IN_TREE_EARLY_TAS=trusted_keys/f04a0fe7-1f5d-4b9b-abf7-619b85b4ce8c
# Run QEMU setup $ make run-only # Type "c" on QEMU console to continue boot
# Now there should be two virtual consoles up, one for OP-TEE and other for Linux # On Linux console, you can play with "keyctl" utility to have trusted and encrypted keys based on TEE.
Do let me know in case you are stuck while following the above steps.
[1] https://optee.readthedocs.io/en/latest/building/devices/qemu.html#qemu-v8 [2] https://optee.readthedocs.io/en/latest/building/prerequisites.html#prerequis... [3] https://lkml.org/lkml/2020/5/4/1062
-Sumit
Thanks I'll try this out as soon as the v5.8 release hassle is over!
/Jarkko
Update documentation for Trusted and Encrypted Keys with TEE as a new trust source. Following is brief description of updates:
- Add a section to demostrate a list of supported devices along with their security properties/guarantees. - Add a key generation section. - Updates for usage section including differences specific to a trust source.
Signed-off-by: Sumit Garg sumit.garg@linaro.org --- Documentation/security/keys/trusted-encrypted.rst | 203 ++++++++++++++++++---- 1 file changed, 171 insertions(+), 32 deletions(-)
diff --git a/Documentation/security/keys/trusted-encrypted.rst b/Documentation/security/keys/trusted-encrypted.rst index 50ac8bc..4764a6d 100644 --- a/Documentation/security/keys/trusted-encrypted.rst +++ b/Documentation/security/keys/trusted-encrypted.rst @@ -6,30 +6,161 @@ Trusted and Encrypted Keys are two new key types added to the existing kernel key ring service. Both of these new types are variable length symmetric keys, and in both cases all keys are created in the kernel, and user space sees, stores, and loads only encrypted blobs. Trusted Keys require the availability -of a Trusted Platform Module (TPM) chip for greater security, while Encrypted -Keys can be used on any system. All user level blobs, are displayed and loaded -in hex ascii for convenience, and are integrity verified. +of a Trust Source for greater security, while Encrypted Keys can be used on any +system. All user level blobs, are displayed and loaded in hex ascii for +convenience, and are integrity verified.
-Trusted Keys use a TPM both to generate and to seal the keys. Keys are sealed -under a 2048 bit RSA key in the TPM, and optionally sealed to specified PCR -(integrity measurement) values, and only unsealed by the TPM, if PCRs and blob -integrity verifications match. A loaded Trusted Key can be updated with new -(future) PCR values, so keys are easily migrated to new pcr values, such as -when the kernel and initramfs are updated. The same key can have many saved -blobs under different PCR values, so multiple boots are easily supported.
-TPM 1.2 -------- +Trust Source +============
-By default, trusted keys are sealed under the SRK, which has the default -authorization value (20 zeros). This can be set at takeownership time with the -trouser's utility: "tpm_takeownership -u -z". +Trust Source provides the source of security for the Trusted Keys, on which +basis Trusted Keys establishes a Trust model with its user. A Trust Source could +differ from one system to another depending on its security requirements. It +could be either an off-chip device or an on-chip device. Following section +demostrates a list of supported devices along with their security properties/ +guarantees:
-TPM 2.0 -------- + * Root of trust for storage
-The user must first create a storage key and make it persistent, so the key is -available after reboot. This can be done using the following commands. + (1) TPM (Trusted Platform Module: hardware device) + + Rooted to Storage Root Key (SRK) which never leaves the TPM that + provides crypto operation to establish root of trust for storage. + + (2) TEE (Trusted Execution Environment: OP-TEE based on Arm TrustZone) + + Rooted to Hardware Unique Key (HUK) which is generally burnt in on-chip + fuses and is accessible to TEE only. + + * Execution isolation + + (1) TPM + + Fixed set of operations running in isolated execution environment. + + (2) TEE + + Customizable set of operations running in isolated execution + environment verified via Secure/Trusted boot process. + + * Optional binding to platform integrity state + + (1) TPM + + Keys can be optionally sealed to specified PCR (integrity measurement) + values, and only unsealed by the TPM, if PCRs and blob integrity + verifications match. A loaded Trusted Key can be updated with new + (future) PCR values, so keys are easily migrated to new PCR values, + such as when the kernel and initramfs are updated. The same key can + have many saved blobs under different PCR values, so multiple boots are + easily supported. + + (2) TEE + + Relies on Secure/Trusted boot process for platform integrity. It can + be extended with TEE based measured boot process. + + * On-chip versus off-chip + + (1) TPM + + Off-chip device connected via serial bus (like I2C, SPI etc.) exposing + physical access which represents an attack surface that can be + mitigated via tamper detection. + + (2) TEE + + On-chip functionality, immune to this attack surface. + + * Memory attacks (DRAM based like attaching a bus monitor etc.) + + (1) TPM + + Immune to these attacks as it doesn’t make use of system DRAM. + + (2) TEE + + An implementation based on TrustZone protected DRAM is susceptible to + such attacks. In order to mitigate these attacks one needs to rely on + on-chip secure RAM to store secrets or have the entire TEE + implementation based on on-chip secure RAM. An alternative mitigation + would be to use encrypted DRAM. + + * Side-channel attacks (cache, memory, CPU or time based) + + (1) TPM + + Immune to side-channel attacks as its resources are isolated from the + main OS. + + (2) TEE + + A careful implementation is required to mitigate against these attacks + for resources which are shared (eg. shared memory) with the main OS. + Cache and CPU based side-channel attacks can be mitigated via + invalidating caches and CPU registers during context switch to and from + the secure world. + To mitigate against time based attacks, one needs to have time + invariant implementations (like crypto algorithms etc.). + + * Resistance to physical attacks (power analysis, electromagnetic emanation, + probes etc.) + + (1) TPM + + Provides limited protection utilizing tamper resistance. + + (2) TEE + + Provides no protection by itself, relies on the underlying platform for + features such as tamper resistance. + + +Key Generation +============== + +Trusted Keys +------------ + +New keys are created from trust source generated random numbers, and are +encrypted/decrypted using trust source storage root key. + + * TPM (hardware device) based RNG + + Strength of random numbers may vary from one device manufacturer to + another. + + * TEE (OP-TEE based on Arm TrustZone) based RNG + + RNG is customizable as per platform needs. It can either be direct output + from platform specific hardware RNG or a software based Fortuna CSPRNG + which can be seeded via multiple entropy sources. + +Encrypted Keys +-------------- + +Encrypted keys do not depend on a trust source, and are faster, as they use AES +for encryption/decryption. New keys are created from kernel generated random +numbers, and are encrypted/decrypted using a specified ‘master’ key. The +‘master’ key can either be a trusted-key or user-key type. The main disadvantage +of encrypted keys is that if they are not rooted in a trusted key, they are only +as secure as the user key encrypting them. The master user key should therefore +be loaded in as secure a way as possible, preferably early in boot. + + +Usage +===== + +Trusted Keys usage: TPM +----------------------- + +TPM 1.2: By default, trusted keys are sealed under the SRK, which has the +default authorization value (20 zeros). This can be set at takeownership time +with the TrouSerS utility: "tpm_takeownership -u -z". + +TPM 2.0: The user must first create a storage key and make it persistent, so the +key is available after reboot. This can be done using the following commands.
With the IBM TSS 2 stack::
@@ -79,14 +210,21 @@ TPM_STORED_DATA format. The key length for new keys are always in bytes. Trusted Keys can be 32 - 128 bytes (256 - 1024 bits), the upper limit is to fit within the 2048 bit SRK (RSA) keylength, with all necessary structure/padding.
-Encrypted keys do not depend on a TPM, and are faster, as they use AES for -encryption/decryption. New keys are created from kernel generated random -numbers, and are encrypted/decrypted using a specified 'master' key. The -'master' key can either be a trusted-key or user-key type. The main -disadvantage of encrypted keys is that if they are not rooted in a trusted key, -they are only as secure as the user key encrypting them. The master user key -should therefore be loaded in as secure a way as possible, preferably early in -boot. +Trusted Keys usage: TEE +----------------------- + +Usage:: + + keyctl add trusted name "new keylen" ring + keyctl add trusted name "load hex_blob" ring + keyctl print keyid + +"keyctl print" returns an ascii hex copy of the sealed key, which is in format +specific to TEE device implementation. The key length for new keys are always +in bytes. Trusted Keys can be 32 - 128 bytes (256 - 1024 bits). + +Encrypted Keys usage +--------------------
The decrypted portion of encrypted keys can contain either a simple symmetric key or a more complex structure. The format of the more complex structure is @@ -104,8 +242,8 @@ Where:: format:= 'default | ecryptfs | enc32' key-type:= 'trusted' | 'user'
- Examples of trusted and encrypted key usage: +--------------------------------------------
Create and save a trusted key named "kmk" of length 32 bytes.
@@ -151,7 +289,7 @@ Load a trusted key from the saved blob:: f1f8fff03ad0acb083725535636addb08d73dedb9832da198081e5deae84bfaf0409c22b e4a8aea2b607ec96931e6f4d4fe563ba
-Reseal a trusted key under new pcr values:: +Reseal (TPM specific) a trusted key under new PCR values::
$ keyctl update 268728824 "update pcrinfo=`cat pcr.blob`" $ keyctl print 268728824 @@ -165,11 +303,12 @@ Reseal a trusted key under new pcr values:: 7ef6a24defe4846104209bf0c3eced7fa1a672ed5b125fc9d8cd88b476a658a4434644ef df8ae9a178e9f83ba9f08d10fa47e4226b98b0702f06b3b8
+ The initial consumer of trusted keys is EVM, which at boot time needs a high -quality symmetric key for HMAC protection of file metadata. The use of a +quality symmetric key for HMAC protection of file metadata. The use of a trusted key provides strong guarantees that the EVM key has not been -compromised by a user level problem, and when sealed to specific boot PCR -values, protects against boot and offline attacks. Create and save an +compromised by a user level problem, and when sealed to a platform integrity +state, protects against boot and offline attacks. Create and save an encrypted key "evm" using the above trusted key "kmk":
option 1: omitting 'format'::
On Wed, 2020-05-06 at 15:10 +0530, Sumit Garg wrote:
Update documentation for Trusted and Encrypted Keys with TEE as a new trust source. Following is brief description of updates:
- Add a section to demostrate a list of supported devices along with their security properties/guarantees.
- Add a key generation section.
- Updates for usage section including differences specific to a trust source.
Signed-off-by: Sumit Garg sumit.garg@linaro.org
Reviewed-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com
/Jarkko
Add MAINTAINERS entry for TEE based Trusted Keys framework.
Signed-off-by: Sumit Garg sumit.garg@linaro.org --- MAINTAINERS | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS index b816a45..fc8bf16 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -9403,6 +9403,14 @@ F: include/keys/trusted-type.h F: include/keys/trusted_tpm.h F: security/keys/trusted-keys/
+KEYS-TRUSTED-TEE +M: Sumit Garg sumit.garg@linaro.org +L: linux-integrity@vger.kernel.org +L: keyrings@vger.kernel.org +S: Supported +F: include/keys/trusted_tee.h +F: security/keys/trusted-keys/trusted_tee.c + KEYS/KEYRINGS M: David Howells dhowells@redhat.com M: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com
On Wed, 2020-05-06 at 15:10 +0530, Sumit Garg wrote:
Add MAINTAINERS entry for TEE based Trusted Keys framework.
Signed-off-by: Sumit Garg sumit.garg@linaro.org
Acked-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com
/Jarkko
On Wed, 6 May 2020 at 15:10, Sumit Garg sumit.garg@linaro.org wrote:
Add support for TEE based trusted keys where TEE provides the functionality to seal and unseal trusted keys using hardware unique key. Also, this is an alternative in case platform doesn't possess a TPM device.
This patch-set has been tested with OP-TEE based early TA which can be found here [1].
Fyi, this PR has been merged in OP-TEE OS as commit [1]. Looking forward to any further comments/feedback on this patch-set.
[1] https://github.com/OP-TEE/optee_os/commit/f86ab8e7e0de869dfa25ca05a37ee070d7...
-Sumit
Changes in v4:
- Pushed independent TEE features separately:
- Part of recent TEE PR: https://lkml.org/lkml/2020/5/4/1062
- Updated trusted-encrypted doc with TEE as a new trust source.
- Rebased onto latest tpmdd/master.
Changes in v3:
- Update patch #2 to support registration of multiple kernel pages.
- Incoporate dependency patch #4 in this patch-set: https://patchwork.kernel.org/patch/11091435/
Changes in v2:
- Add reviewed-by tags for patch #1 and #2.
- Incorporate comments from Jens for patch #3.
- Switch to use generic trusted keys framework.
Sumit Garg (4): KEYS: trusted: Add generic trusted keys framework KEYS: trusted: Introduce TEE based Trusted Keys doc: trusted-encrypted: updates with TEE as a new trust source MAINTAINERS: Add entry for TEE based Trusted Keys
Documentation/security/keys/trusted-encrypted.rst | 203 ++++++++++--- MAINTAINERS | 8 + include/keys/trusted-type.h | 48 ++++ include/keys/trusted_tee.h | 66 +++++ include/keys/trusted_tpm.h | 15 - security/keys/Kconfig | 3 + security/keys/trusted-keys/Makefile | 2 + security/keys/trusted-keys/trusted_common.c | 336 ++++++++++++++++++++++ security/keys/trusted-keys/trusted_tee.c | 282 ++++++++++++++++++ security/keys/trusted-keys/trusted_tpm1.c | 335 ++++----------------- 10 files changed, 974 insertions(+), 324 deletions(-) create mode 100644 include/keys/trusted_tee.h create mode 100644 security/keys/trusted-keys/trusted_common.c create mode 100644 security/keys/trusted-keys/trusted_tee.c
-- 2.7.4
-
Jarkko Sakkinen -
Sumit Garg