greybus-dev November 2020

greybus-dev@lists.linaro.org

6 participants
4 discussions

by Christopher Friedt

Hi everyone, I thought it might be a good time to start / re-start / join the conversation about authentication and encryption in Greybus, and in particular, for using a transport (and lower layers) other than UniPro. This is the logical next step after getting the TCP/IP transport working with gbridge over BLE, 802.15.4, WiFi, ethernet, UART, etc. There is the Component Authentication Protocol that exists already, but I'm not terribly familiar with it. Is anyone able to clarify if there is some overlap between CAP and some of the work that follows? If it's possible to re-use some of the CAP, that would be nice. Just over a year ago I set up authentication and encryption over Greybus for BeagleBoard.org. I was able to demonstrate it working over a TCP/IP transport. Here is some code that is on the back-burner for now. https://github.com/friedtco/gbridge/blob/feature/tcpip-ble-ipsp/pkauth.h https://github.com/friedtco/gbridge/blob/feature/tcpip-ble-ipsp/pkauth.c I have a PR open to anobli/gbridge on GitHub that pulls in the non-authentication / encryption changes. So the change that deals with auth and encryption is fairly small. On the Host side, it uses OpenSSL. We are using regular SSH keys for asymmetric authentication and the initial secure channel, then generating and sharing an AES-128 session key for symmetric encryption of the subsequent communications. The wireless SoC we're using for testing is the CC1352R from TI, and it has both AES and PK hardware accelerators. Most SoC's these days have an AES accelerator, at least. The handshake is described here, but I'll copy it into the email as well. https://github.com/friedtco/gbridge/blob/feature/tcpip-ble-ipsp/pkauth.c#L1… 1. Device sends its public key 2. Host compares device public key with those in a collection of trusted public keys. if not found connection closed. 3. Host sends its public key 4. Device compares host public key with those in a collection of trusted public keys. if not found connection closed. 5. Device creates a randomly generated message, "PlainText A". 6. Device encrypts "PlainText A" using Host public key, creating "CipherText A". 7. Device transmits "CipherText A" to Host. 8. Host decrypts "CipherText A" with Host private key, resulting in "PlainText B". 9. Host encrypts "PlainText B" using Device public key, creating "CipherText B". 10. Host transmits "CipherText B" to Device. 11. Device decrypts "CipherText B" with Device private key, resulting in "PlainText C". 12. Device compares "PlainText A" and "PlainText C", and responds with success or noauth. 13. Host creates a randomly generated message, "PlainText D". 14. Host encrypts "PlainText D" using Device public key, creating "CipherText D". 15. Host transmits "CipherText D" to Device. 16. Device decrypts "CipherText D" with Device private key, resulting in "PlainText E". 17. Device encrypts "PlainText E" using Host public key, creating "CipherText E". 18. Device transmits "CipherText E" to Host. 19. Host decrypts "CipherText E" with Host private key, resulting in "PlainText F". 20. Host compares "PlainText D" and "PlainText F", and responds with success or noauth. 21. Host generates symmetric session key as "PlainText G", pairs session key with socket. 22. Host encrypts "PlainText G" with Device public key, resulting in "CipherText G". 23. Host transmits "CipherText G" to device. 24. Device decrypts "CipherText G" using Device private key, resulting in "PlainText H". 25. Device pairs the session key ("PlainText H") with socket. Currently, this handshake happens when a new connection is created on any port / CPort (be it Control, GPIO, I2C, SPI, etc). While I understand that this security mechanism is not nearly as sophisticated as that of Thread, for example, it's fairly easy to implement locally for developers. However, we would ultimately like to support more than one method of authentication and encryption in Greybus. For the very basic method we implemented above, 5 additional message primitives were required: https://github.com/friedtco/gbridge/blob/feature/tcpip-ble-ipsp/pkauth.h#L32 #define GB_PKAUTH_TYPE_VERSION 0x7a #define GB_PKAUTH_TYPE_PUBKEY 0x7b #define GB_PKAUTH_TYPE_CHALLENGE 0x7c #define GB_PKAUTH_TYPE_CHALLENGE_RESP 0x7d #define GB_PKAUTH_TYPE_SESSION_KEY 0x7e For full negotiation of the auth mechanism and encryption algorithm (e.g. OAuth2 authentication + 3DES encryption) we'll probably need a few more message primitives, and likely a new minor version (at least) for each CPort protocol. It should be possible (although discouraged) to opt for everything in plaintext, but that would also be the default case for the CPort protocols as they exist today. I would love to hear some ideas about this from whoever is interested. Cheers, C

3 years, 12 months

[PATCH] Fix warning for static const char * array in audio_manager_module.c

by Emmanouil Perselis

On 11/15/20 9:17 AM, Greg Kroah-Hartman wrote: > On Sun, Nov 15, 2020 at 03:53:16PM +0100, Emmanouil Perselis wrote: >> This patch fixes the warning "static const char * array should >> probably be static const char * const" in >> drivers/staging/greybus/audio_manager_module.c >> I think Greg's patch bot is telling you that you need >> to carbon-copy the mailing list on your patch submission, >> not just address it to the maintainers. Added addresses to carbon copy. >> -Alex >> >> Signed-off-by: Emmanouil Perselis <perselis.e(a)gmail.com> >> --- >> drivers/staging/greybus/audio_manager_module.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/staging/greybus/audio_manager_module.c b/drivers/staging/greybus/audio_manager_module.c >> index 2bfd804183c4..6ef7381f4e85 100644 >> --- a/drivers/staging/greybus/audio_manager_module.c >> +++ b/drivers/staging/greybus/audio_manager_module.c >> @@ -158,7 +158,7 @@ static void send_add_uevent(struct gb_audio_manager_module *module) >> char ip_devices_string[64]; >> char op_devices_string[64]; >> >> - char *envp[] = { >> + static const char * const envp[] = { >> name_string, >> vid_string, >> pid_string, >> -- >> 2.20.1 >> > > Hi, > > This is the friendly patch-bot of Greg Kroah-Hartman. You have sent him > a patch that has triggered this response. He used to manually respond > to these common problems, but in order to save his sanity (he kept > writing the same thing over and over, yet to different people), I was > created. Hopefully you will not take offence and will fix the problem > in your patch and resubmit it so that it can be accepted into the Linux > kernel tree. > > You are receiving this message because of the following common error(s) > as indicated below: > > - Your patch was sent privately to Greg. Kernel development is done in > public, please always cc: a public mailing list with a patch > submission. Using the tool, scripts/get_maintainer.pl on the patch > will tell you what mailing list to cc. > > - You did not specify a description of why the patch is needed, or > possibly, any description at all, in the email body. Please read the > section entitled "The canonical patch format" in the kernel file, > Documentation/SubmittingPatches for what is needed in order to > properly describe the change. > > - You did not write a descriptive Subject: for the patch, allowing Greg, > and everyone else, to know what this patch is all about. Please read > the section entitled "The canonical patch format" in the kernel file, > Documentation/SubmittingPatches for what a proper Subject: line should > look like. > > If you wish to discuss this problem further, or you have questions about > how to resolve this issue, please feel free to respond to this email and > Greg will reply once he has dug out from the pending patches received > from other developers. > > thanks, > > greg k-h's patch email bot > Signed-off-by: Emmanouil Perselis <perselis.e(a)gmail.com> --- drivers/staging/greybus/audio_manager_module.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/greybus/audio_manager_module.c b/drivers/staging/greybus/audio_manager_module.c index 2bfd804183c4..6ef7381f4e85 100644 --- a/drivers/staging/greybus/audio_manager_module.c +++ b/drivers/staging/greybus/audio_manager_module.c @@ -158,7 +158,7 @@ static void send_add_uevent(struct gb_audio_manager_module *module) char ip_devices_string[64]; char op_devices_string[64]; - char *envp[] = { + static const char * const envp[] = { name_string, vid_string, pid_string, -- 2.20.1

4 years, 1 month

[PATCH v2 2/2] greybus: audio: apbridgea: Fix reference counter leak in error handling

by Zhang Qilong

When gb_audio_apbridgea_register_cport failed, maybe: 1) gb_pm_runtime_get_sync failed, usage counter remained unchanged; 2) gb_hd_output failed, usage counter remained increased; In error state, there are two different states in usage cpounter. So, if gb_hd_output failed, we should call gb_pm_runtime_put_autosuspend ot decrease usage counter for balabce preventing reference leak. And we fixed it by add gb_pm_runtime_put_autosuspend when gb_hd_output failed. Fixes: 6ba7fad430d63 ("greybus: audio: add runtime pm support") Signed-off-by: Zhang Qilong <zhangqilong3(a)huawei.com> --- Changelog: v2 - fix the name for fixed commit id --- drivers/staging/greybus/audio_apbridgea.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/staging/greybus/audio_apbridgea.c b/drivers/staging/greybus/audio_apbridgea.c index 26117e390deb..50545fd9756c 100644 --- a/drivers/staging/greybus/audio_apbridgea.c +++ b/drivers/staging/greybus/audio_apbridgea.c @@ -42,8 +42,12 @@ int gb_audio_apbridgea_register_cport(struct gb_connection *connection, if (ret) return ret; - return gb_hd_output(connection->hd, &req, sizeof(req), + ret = gb_hd_output(connection->hd, &req, sizeof(req), GB_APB_REQUEST_AUDIO_CONTROL, true); + if (ret) + gb_pm_runtime_put_autosuspend(connection->bundle); + + return ret; } EXPORT_SYMBOL_GPL(gb_audio_apbridgea_register_cport); -- 2.25.4

4 years, 1 month

[PATCH 0/2] Fix reference counter leak in error banch

by Zhang Qilong

There are two reference counter leaks in greybus moduler refer to gb_pm_runtime_get_sync, and we fixed it. Zhang Qilong (2): staging: greybus: codecs: Fix reference counter leak in error handling greybus: audio: apbridgea: Fix reference counter leak in error handling drivers/staging/greybus/audio_apbridgea.c | 6 +++++- drivers/staging/greybus/audio_codec.c | 2 ++ 2 files changed, 7 insertions(+), 1 deletion(-) -- 2.25.4

4 years, 1 month

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greybus-dev November 2020