Key agreement: macros for finite-field Diffie-Hellman, ECDH

Declare macros to represent key agreement algorithms.
This commit is contained in:
Gilles Peskine 2018-09-18 11:54:43 +02:00
parent e8f0e3dc3c
commit 93098fd996
3 changed files with 98 additions and 0 deletions

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@ -1218,6 +1218,73 @@ typedef uint32_t psa_algorithm_t;
#define PSA_ALG_KEY_AGREEMENT_GET_BASE(alg) \
((alg) & ~PSA_ALG_KEY_DERIVATION_MASK)
#define PSA_ALG_FFDH_BASE ((psa_algorithm_t)0x22100000)
/** The Diffie-Hellman key agreement algorithm.
*
* This algorithm combines the finite-field Diffie-Hellman-Merkle key
* agreement to produce a shared secret from a private key and the peer's
* public key, with a key selection or key derivation algorithm to produce
* one or more shared keys and other shared cryptographic material.
*
* \param kdf_alg A key derivation algorithm (\c PSA_ALG_XXX value such
* that #PSA_ALG_IS_KEY_DERIVATION(\p hash_alg) is true)
* or a key selection algorithm (\c PSA_ALG_XXX value such
* that #PSA_ALG_IS_SELECTION(\p hash_alg) is true).
*
* \return The Diffie-Hellman algorithm with the specified
* selection or derivation algorithm.
*/
#define PSA_ALG_FFDH(kdf_alg) \
(PSA_ALG_FFDH_BASE | ((kdf_alg) & PSA_ALG_KEY_DERIVATION_MASK))
/** Whether the specified algorithm is a finite field Diffie-Hellman algorithm.
*
* This includes every supported key selection or key agreement algorithm
* for the output of the Diffie-Hellman calculation.
*
* \param alg An algorithm identifier (value of type #psa_algorithm_t).
*
* \return 1 if \c alg is a finite field Diffie-Hellman algorithm, 0 otherwise.
* This macro may return either 0 or 1 if \c alg is not a supported
* key agreement algorithm identifier.
*/
#define PSA_ALG_IS_FFDH(alg) \
(PSA_ALG_KEY_AGREEMENT_GET_BASE(alg) == PSA_ALG_FFDH_BASE)
#define PSA_ALG_ECDH_BASE ((psa_algorithm_t)0x22200000)
/** The elliptic curve Diffie-Hellman key agreement algorithm.
*
* This algorithm combines the elliptic curve Diffie-Hellman key
* agreement to produce a shared secret from a private key and the peer's
* public key, with a key selection or key derivation algorithm to produce
* one or more shared keys and other shared cryptographic material.
*
* \param kdf_alg A key derivation algorithm (\c PSA_ALG_XXX value such
* that #PSA_ALG_IS_KEY_DERIVATION(\p hash_alg) is true)
* or a selection algorithm (\c PSA_ALG_XXX value such
* that #PSA_ALG_IS_KEY_SELECTION(\p hash_alg) is true).
*
* \return The Diffie-Hellman algorithm with the specified
* selection or derivation algorithm.
*/
#define PSA_ALG_ECDH(kdf_alg) \
(PSA_ALG_ECDH_BASE | ((kdf_alg) & PSA_ALG_KEY_DERIVATION_MASK))
/** Whether the specified algorithm is an elliptic curve Diffie-Hellman
* algorithm.
*
* This includes every supported key selection or key agreement algorithm
* for the output of the Diffie-Hellman calculation.
*
* \param alg An algorithm identifier (value of type #psa_algorithm_t).
*
* \return 1 if \c alg is an elliptic curve Diffie-Hellman algorithm,
* 0 otherwise.
* This macro may return either 0 or 1 if \c alg is not a supported
* key agreement algorithm identifier.
*/
#define PSA_ALG_IS_ECDH(alg) \
(PSA_ALG_KEY_AGREEMENT_GET_BASE(alg) == PSA_ALG_ECDH_BASE)
/**@}*/
/** \defgroup key_management Key management