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

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;

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