diff --git a/3rdparty/p256-m/p256-m/p256-m.c b/3rdparty/p256-m/p256-m/p256-m.c index 53d306f63..de550cf8e 100644 --- a/3rdparty/p256-m/p256-m/p256-m.c +++ b/3rdparty/p256-m/p256-m/p256-m.c @@ -1468,4 +1468,49 @@ int p256_ecdsa_verify(const uint8_t sig[64], const uint8_t pub[64], return P256_INVALID_SIGNATURE; } +/********************************************************************** + * + * Key management utilities + * + **********************************************************************/ + +int p256_validate_pubkey(const uint8_t pub[64]) +{ + uint32_t x[8], y[8]; + int ret = point_from_bytes(x, y, pub); + + return ret == 0 ? P256_SUCCESS : P256_INVALID_PUBKEY; +} + +int p256_validate_privkey(const uint8_t priv[32]) +{ + uint32_t s[8]; + int ret = scalar_from_bytes(s, priv); + zeroize(s, sizeof(s)); + + return ret == 0 ? P256_SUCCESS : P256_INVALID_PRIVKEY; +} + +int p256_public_from_private(uint8_t pub[64], const uint8_t priv[32]) +{ + int ret; + uint32_t s[8]; + + ret = scalar_from_bytes(s, priv); + if (ret != 0) + return P256_INVALID_PRIVKEY; + + /* compute and ouput the associated public key */ + uint32_t x[8], y[8]; + scalar_mult(x, y, p256_gx, p256_gy, s); + + /* the associated public key is not a secret, the scalar was */ + CT_UNPOISON(x, 32); + CT_UNPOISON(y, 32); + zeroize(s, sizeof(s)); + + point_to_bytes(pub, x, y); + return P256_SUCCESS; +} + #endif diff --git a/3rdparty/p256-m/p256-m/p256-m.h b/3rdparty/p256-m/p256-m/p256-m.h index 398c8469f..d4b053ad0 100644 --- a/3rdparty/p256-m/p256-m/p256-m.h +++ b/3rdparty/p256-m/p256-m/p256-m.h @@ -89,6 +89,45 @@ int p256_ecdsa_sign(uint8_t sig[64], const uint8_t priv[32], int p256_ecdsa_verify(const uint8_t sig[64], const uint8_t pub[64], const uint8_t *hash, size_t hlen); +/* + * Public key validation + * + * Note: you never need to call this function, as all other function always + * validate their input; however it's availabe if you want to validate the key + * without performing an operation. + * + * [in] pub: the public key, as two big-endian integers + * + * return: P256_SUCCESS if the key is valid + * P256_INVALID_PUBKEY if pub is invalid + */ +int p256_validate_pubkey(const uint8_t pub[64]); + +/* + * Private key validation + * + * Note: you never need to call this function, as all other function always + * validate their input; however it's availabe if you want to validate the key + * without performing an operation. + * + * [in] priv: the private key, as a big-endian integer + * + * return: P256_SUCCESS if the key is valid + * P256_INVALID_PRIVKEY if priv is invalid + */ +int p256_validate_privkey(const uint8_t priv[32]); + +/* + * Compute public key from private key + * + * [out] pub: the associated public key, as two big-endian integers + * [in] priv: the private key, as a big-endian integer + * + * return: P256_SUCCESS on success + * P256_INVALID_PRIVKEY if priv is invalid + */ +int p256_public_from_private(uint8_t pub[64], const uint8_t priv[32]); + #ifdef __cplusplus } #endif