New API function: psa_key_agreement
Set up a generator from a key agreement.
diff --git a/include/psa/crypto.h b/include/psa/crypto.h
index 8059ab9..8fb641f 100644
--- a/include/psa/crypto.h
+++ b/include/psa/crypto.h
@@ -3191,6 +3191,46 @@
size_t label_length,
size_t capacity);
+/** Set up a key agreement operation.
+ *
+ * A key agreement algorithm takes two inputs: a private key \p private_key
+ * a public key \p peer_key.
+ * The result of this function is a byte generator which can
+ * be used to produce keys and other cryptographic material.
+ *
+ * \param[in,out] generator The generator object to set up. It must
+ * have been initialized to all-bits-zero,
+ * a logical zero (`{0}`),
+ * \c PSA_CRYPTO_GENERATOR_INIT or
+ * psa_crypto_generator_init().
+ * \param private_key Slot containing the private key to use.
+ * \param[in] peer_key Public key of the peer.
+ * \param peer_key_length Size of \p peer_key in bytes.
+ * \param alg The key agreement algorithm to compute
+ * (\c PSA_ALG_XXX value such that
+ * #PSA_ALG_IS_KEY_AGREEMENT(\p alg) is true).
+ *
+ * \retval #PSA_SUCCESS
+ * Success.
+ * \retval #PSA_ERROR_EMPTY_SLOT
+ * \retval #PSA_ERROR_NOT_PERMITTED
+ * \retval #PSA_ERROR_INVALID_ARGUMENT
+ * \c private_key is not compatible with \c alg,
+ * or \p peer_key is not valid for \c alg or not compatible with
+ * \c private_key.
+ * \retval #PSA_ERROR_NOT_SUPPORTED
+ * \c alg is not supported or is not a key derivation algorithm.
+ * \retval #PSA_ERROR_INSUFFICIENT_MEMORY
+ * \retval #PSA_ERROR_COMMUNICATION_FAILURE
+ * \retval #PSA_ERROR_HARDWARE_FAILURE
+ * \retval #PSA_ERROR_TAMPERING_DETECTED
+ */
+psa_status_t psa_key_agreement(psa_crypto_generator_t *generator,
+ psa_key_slot_t private_key,
+ const uint8_t *peer_key,
+ size_t peer_key_length,
+ psa_algorithm_t alg);
+
/**@}*/
/** \defgroup random Random generation