Skip to main content
Version: Next

Crypto API: Public-key cryptography

noxtls-crypto::pkc provides RSA, ECC (P-256), Ed25519, and post-quantum helpers used by TLS and PKI flows.

P-256 APIs​

pub fn noxtls_p256_generate_private_key_auto(drbg: &mut HmacDrbgSha256) -> Result<P256PrivateKey>
pub fn noxtls_p256_ecdh_shared_secret(
    private_key: &P256PrivateKey,
    peer_public_key: &P256PublicKey,
) -> Result<[u8; 32]>
pub fn noxtls_p256_ecdsa_sign_sha256(
    private_key: &P256PrivateKey,
    message: &[u8],
) -> Result<([u8; 32], [u8; 32])>
pub fn noxtls_p256_ecdsa_verify_sha256(
    public_key: &P256PublicKey,
    message: &[u8],
    r: &[u8; 32],
    s: &[u8; 32],
) -> Result<()>
  • noxtls_p256_generate_private_key_auto draws scalar candidates from DRBG.
  • ECDSA signatures are represented as raw (r, s) scalar arrays.

Ed25519 APIs​

pub fn noxtls_ed25519_generate_private_key_auto(drbg: &mut HmacDrbgSha256) -> Result<Ed25519PrivateKey>
pub fn noxtls_ed25519_verify(
    public_key: &Ed25519PublicKey,
    message: &[u8],
    signature: &[u8],
) -> Result<()>
  • signature must be exactly 64 bytes.

RSA APIs​

pub fn noxtls_rsa_generate_keypair_secure_auto(
    modulus_bits: usize,
    policy: RsaKeySizePolicy,
    drbg: &mut HmacDrbgSha256,
) -> Result<(RsaPrivateKey, RsaPublicKey)>
  • modulus_bits: key size request.
  • policy: enforces minimum/allowed modulus rules.
pub fn noxtls_rsassa_pss_sha256_sign_auto(
    private: &RsaPrivateKey,
    msg: &[u8],
    drbg: &mut HmacDrbgSha256,
    salt_len: usize,
) -> Result<Vec<u8>>
pub fn noxtls_rsassa_pss_sha256_verify(
    public: &RsaPublicKey,
    msg: &[u8],
    signature: &[u8],
    salt_len: usize,
) -> Result<()>
  • salt_len must match verifier expectation.
pub fn noxtls_rsaes_oaep_sha256_encrypt_auto(
    public: &RsaPublicKey,
    plaintext: &[u8],
    label: &[u8],
    drbg: &mut HmacDrbgSha256,
) -> Result<Vec<u8>>
pub fn noxtls_rsaes_oaep_sha256_decrypt(
    private: &RsaPrivateKey,
    ciphertext: &[u8],
    label: &[u8],
) -> Result<Vec<u8>>
  • label must match on encrypt/decrypt.

Security guidance​

  • Prefer PSS/OAEP over PKCS#1 v1.5 for new integrations.
  • Keep DRBG health/reseed policy explicit for key generation paths.
  • Consider RsaKeySizePolicy strict modes for long-lived credentials.

Per-algorithm pages​

RSA, ECC / P-256, Ed25519, X25519, X448, ML-KEM, ML-DSA, plus Ed448, DH, and DSA status pages. Full index: API index.