/**
* Copyright Notice:
* Copyright 2021-2022 DMTF. All rights reserved.
* License: BSD 3-Clause License. For full text see link: https://github.com/DMTF/libspdm/blob/main/LICENSE.md
**/
#ifndef CRYPTLIB_EC_H
#define CRYPTLIB_EC_H
/*=====================================================================================
* Elliptic Curve Primitives
*=====================================================================================*/
#if (LIBSPDM_ECDHE_SUPPORT) || (LIBSPDM_ECDSA_SUPPORT)
/**
* Allocates and Initializes one Elliptic Curve context for subsequent use with the NID.
*
* @param nid cipher NID
*
* @return Pointer to the Elliptic Curve context that has been initialized.
* If the allocations fails, libspdm_ec_new_by_nid() returns NULL.
**/
extern void *libspdm_ec_new_by_nid(size_t nid);
/**
* Release the specified EC context.
*
* @param[in] ec_context Pointer to the EC context to be released.
**/
extern void libspdm_ec_free(void *ec_context);
#if LIBSPDM_FIPS_MODE
/**
* Sets the private key component into the established EC context.
*
* For P-256, the private_key_size is 32 byte.
* For P-384, the private_key_size is 48 byte.
* For P-521, the private_key_size is 66 byte.
*
* @param[in, out] ec_context Pointer to EC context being set.
* @param[in] private_key Pointer to the private key buffer.
* @param[in] private_key_size The size of private key buffer in bytes.
*
* @retval true EC private key component was set successfully.
* @retval false Invalid EC private key component.
*
**/
extern bool libspdm_ec_set_priv_key(void *ec_context, const uint8_t *private_key,
size_t private_key_size);
/**
* Sets the public key component into the established EC context.
*
* For P-256, the public_size is 64. first 32-byte is X, second 32-byte is Y.
* For P-384, the public_size is 96. first 48-byte is X, second 48-byte is Y.
* For P-521, the public_size is 132. first 66-byte is X, second 66-byte is Y.
*
* @param[in, out] ec_context Pointer to EC context being set.
* @param[in] public Pointer to the buffer to receive generated public X,Y.
* @param[in] public_size The size of public buffer in bytes.
*
* @retval true EC public key component was set successfully.
* @retval false Invalid EC public key component.
**/
extern bool libspdm_ec_set_pub_key(void *ec_context, const uint8_t *public_key,
size_t public_key_size);
#endif /* LIBSPDM_FIPS_MODE */
#endif /* (LIBSPDM_ECDHE_SUPPORT) || (LIBSPDM_ECDSA_SUPPORT) */
#if LIBSPDM_ECDHE_SUPPORT
/**
* Generates EC key and returns EC public key (X, Y).
*
* This function generates random secret, and computes the public key (X, Y), which is
* returned via parameter public, public_size.
* X is the first half of public with size being public_size / 2,
* Y is the second half of public with size being public_size / 2.
* EC context is updated accordingly.
* If the public buffer is too small to hold the public X, Y, false is returned and
* public_size is set to the required buffer size to obtain the public X, Y.
*
* For P-256, the public_size is 64. first 32-byte is X, second 32-byte is Y.
* For P-384, the public_size is 96. first 48-byte is X, second 48-byte is Y.
* For P-521, the public_size is 132. first 66-byte is X, second 66-byte is Y.
*
* If ec_context is NULL, then return false.
* If public_size is NULL, then return false.
* If public_size is large enough but public is NULL, then return false.
*
* @param[in, out] ec_context Pointer to the EC context.
* @param[out] public Pointer to the buffer to receive generated public X,Y.
* @param[in, out] public_size On input, the size of public buffer in bytes.
* On output, the size of data returned in public buffer in bytes.
*
* @retval true EC public X,Y generation succeeded.
* @retval false EC public X,Y generation failed.
* @retval false public_size is not large enough.
**/
extern bool libspdm_ec_generate_key(void *ec_context, uint8_t *public_key, size_t *public_key_size);
/**
* Computes exchanged common key.
*
* Given peer's public key (X, Y), this function computes the exchanged common key,
* based on its own context including value of curve parameter and random secret.
* X is the first half of peer_public with size being peer_public_size / 2,
* Y is the second half of peer_public with size being peer_public_size / 2.
*
* If ec_context is NULL, then return false.
* If peer_public is NULL, then return false.
* If peer_public_size is 0, then return false.
* If key is NULL, then return false.
* If key_size is not large enough, then return false.
*
* For P-256, the peer_public_size is 64. first 32-byte is X, second 32-byte is Y.
* The key_size is 32.
* For P-384, the peer_public_size is 96. first 48-byte is X, second 48-byte is Y.
* The key_size is 48.
* For P-521, the peer_public_size is 132. first 66-byte is X, second 66-byte is Y.
* The key_size is 66.
*
* @param[in, out] ec_context Pointer to the EC context.
* @param[in] peer_public Pointer to the peer's public X,Y.
* @param[in] peer_public_size Size of peer's public X,Y in bytes.
* @param[out] key Pointer to the buffer to receive generated key.
* @param[in, out] key_size On input, the size of key buffer in bytes.
* On output, the size of data returned in key buffer in bytes.
*
* @retval true EC exchanged key generation succeeded.
* @retval false EC exchanged key generation failed.
* @retval false key_size is not large enough.
**/
extern bool libspdm_ec_compute_key(void *ec_context, const uint8_t *peer_public,
size_t peer_public_size, uint8_t *key,
size_t *key_size);
#endif /* LIBSPDM_ECDHE_SUPPORT */
#if LIBSPDM_ECDSA_SUPPORT
/**
* Generates Elliptic Curve context from DER-encoded public key data.
*
* The public key is ASN.1 DER-encoded as RFC7250 describes,
* namely, the SubjectPublicKeyInfo structure of a X.509 certificate.
*
* @param[in] der_data Pointer to the DER-encoded public key data.
* @param[in] der_size Size of the DER-encoded public key data in bytes.
* @param[out] ec_context Pointer to newly generated EC context which contains the
* EC public key component.
* Use libspdm_ec_free() function to free the resource.
*
* If der_data is NULL, then return false.
* If ec_context is NULL, then return false.
*
* @retval true EC context was generated successfully.
* @retval false Invalid DER public key data.
*
**/
extern bool libspdm_ec_get_public_key_from_der(const uint8_t *der_data,
size_t der_size,
void **ec_context);
/**
* Carries out the EC-DSA signature.
*
* This function carries out the EC-DSA signature.
* If the signature buffer is too small to hold the contents of signature, false
* is returned and sig_size is set to the required buffer size to obtain the signature.
*
* If ec_context is NULL, then return false.
* If message_hash is NULL, then return false.
* If hash_size need match the hash_nid. hash_nid could be SHA256, SHA384, SHA512, SHA3_256,
* SHA3_384, SHA3_512.
* If sig_size is large enough but signature is NULL, then return false.
*
* For P-256, the sig_size is 64. first 32-byte is R, second 32-byte is S.
* For P-384, the sig_size is 96. first 48-byte is R, second 48-byte is S.
* For P-521, the sig_size is 132. first 66-byte is R, second 66-byte is S.
*
* @param[in] ec_context Pointer to EC context for signature generation.
* @param[in] hash_nid hash NID
* @param[in] message_hash Pointer to octet message hash to be signed.
* @param[in] hash_size Size of the message hash in bytes.
* @param[out] signature Pointer to buffer to receive EC-DSA signature.
* @param[in, out] sig_size On input, the size of signature buffer in bytes.
* On output, the size of data returned in signature buffer in bytes.
*
* @retval true signature successfully generated in EC-DSA.
* @retval false signature generation failed.
* @retval false sig_size is too small.
**/
extern bool libspdm_ecdsa_sign(void *ec_context, size_t hash_nid,
const uint8_t *message_hash, size_t hash_size,
uint8_t *signature, size_t *sig_size);
#if LIBSPDM_FIPS_MODE
/**
* Carries out the EC-DSA signature with caller input random function. This API can be used for FIPS test.
*
* @param[in] ec_context Pointer to EC context for signature generation.
* @param[in] hash_nid hash NID
* @param[in] message_hash Pointer to octet message hash to be signed.
* @param[in] hash_size Size of the message hash in bytes.
* @param[out] signature Pointer to buffer to receive EC-DSA signature.
* @param[in, out] sig_size On input, the size of signature buffer in bytes.
* On output, the size of data returned in signature buffer in bytes.
* @param[in] random_func random number function
*
* @retval true signature successfully generated in EC-DSA.
* @retval false signature generation failed.
* @retval false sig_size is too small.
**/
extern bool libspdm_ecdsa_sign_ex(void *ec_context, size_t hash_nid,
const uint8_t *message_hash, size_t hash_size,
uint8_t *signature, size_t *sig_size,
int (*random_func)(void *, unsigned char *, size_t));
#endif/*LIBSPDM_FIPS_MODE*/
/**
* Verifies the EC-DSA signature.
*
* If ec_context is NULL, then return false.
* If message_hash is NULL, then return false.
* If signature is NULL, then return false.
* If hash_size need match the hash_nid. hash_nid could be SHA256, SHA384, SHA512, SHA3_256,
* SHA3_384, SHA3_512.
*
* For P-256, the sig_size is 64. first 32-byte is R, second 32-byte is S.
* For P-384, the sig_size is 96. first 48-byte is R, second 48-byte is S.
* For P-521, the sig_size is 132. first 66-byte is R, second 66-byte is S.
*
* @param[in] ec_context Pointer to EC context for signature verification.
* @param[in] hash_nid hash NID
* @param[in] message_hash Pointer to octet message hash to be checked.
* @param[in] hash_size Size of the message hash in bytes.
* @param[in] signature Pointer to EC-DSA signature to be verified.
* @param[in] sig_size Size of signature in bytes.
*
* @retval true Valid signature encoded in EC-DSA.
* @retval false Invalid signature or invalid EC context.
**/
extern bool libspdm_ecdsa_verify(void *ec_context, size_t hash_nid,
const uint8_t *message_hash, size_t hash_size,
const uint8_t *signature, size_t sig_size);
#endif /* LIBSPDM_ECDSA_SUPPORT */
#endif /* CRYPTLIB_EC_H */