Re: [PATCH bpf-next v4 3/6] bpf: Add hash kfunc for cryptographic hashing

On 05/01/2026 17:37, Daniel Hodges wrote:

Extend bpf_crypto_type structure with hash operations:

• hash(): Performs hashing operation
• digestsize(): Returns hash output size

well, as I've already mentioned, none of them are actually introduced in the patchset.

Update bpf_crypto_ctx_create() to support keyless operations:

• Hash algorithms don't require keys, unlike ciphers
• Only validates key presence if type->setkey is defined
• Conditionally sets IV/state length for cipher operations only

Add bpf_crypto_hash() kfunc that works with any hash algorithm registered in the kernel's crypto API through the BPF crypto type system. This enables BPF programs to compute cryptographic hashes for use cases such as content verification, integrity checking, and data authentication.

Signed-off-by: Daniel Hodges git@danielhodges.dev

kernel/bpf/crypto.c | 78 ++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 70 insertions(+), 8 deletions(-)