Re: [PATCH bpf-next v4 5/6] bpf: Add ECDSA signature verification kfuncs

Vadim Fedorenko
2026-01-06T23:12:14Z

On 05/01/2026 17:37, Daniel Hodges wrote:
> Add support for ECDSA signature verification in BPF programs through
> the unified bpf_crypto_ctx API.
>
> Changes:
> - Add enum bpf_crypto_type_id for efficient type checking
> - Update all crypto type modules to set type_id field
> - Implement bpf_ecdsa_verify() for signature verification
> - Add bpf_ecdsa_keysize(), bpf_ecdsa_digestsize(), bpf_ecdsa_maxsize()
> helper functions for querying context properties
> - Add type_id checks in all ECDSA kfuncs for type safety
> - Register ECDSA kfuncs for SCHED_CLS and XDP program types
>
> ECDSA contexts are created using bpf_crypto_ctx_create() with
> type="sig" and appropriate algorithm (e.g., "p1363(ecdsa-nist-p256)").
> The public key is passed via the key/key_len fields in bpf_crypto_params.
>
> This enables BPF programs to perform cryptographic signature verification
> for use cases such as packet authentication and content validation.
>
> Signed-off-by: Daniel Hodges <git@danielhodges.dev>
> @@ -57,6 +58,7 @@ struct bpf_crypto_ctx {
> refcount_t usage;
> };
>
> +
> int bpf_crypto_register_type(const struct bpf_crypto_type *type)
> {
> struct bpf_crypto_type_list *node;

This chunk is extra empty line - no need for it