commit dcaefae8491d955a230245ffd85b6daaa6630c0f
author Gilles Peskine <Gilles.Peskine@arm.com> Thu May 16 12:55:35 2019 +0200
committer Gilles Peskine <Gilles.Peskine@arm.com> Thu May 16 19:51:10 2019 +0200
tree 3438d226098b25c6cbcd375401e15fd47feefd7a
parent 24f10f85e2d771d8eccd5b1f5674ac57327e8dc6

Parametrize Diffie-Hellman keys by a group identifier

Parametrize finite-field Diffie-Hellman key types with a DH group
identifier, in the same way elliptic curve keys are parametrized with
an EC curve identifier.

Define the DH groups from the TLS registry (these are the groups from
RFC 7919).

Replicate the macro definitions and the metadata tests from elliptic
curve identifiers to DH group identifiers.

Define PSA_DH_GROUP_CUSTOM as an implementation-specific extension for
which domain parameters are used to specify the group.

include/psa/crypto_extra.h

diff --git a/include/psa/crypto_extra.h b/include/psa/crypto_extra.h
index 5016ba8..37d9b40 100644
--- a/include/psa/crypto_extra.h
+++ b/include/psa/crypto_extra.h
@@ -449,6 +449,16 @@
  * @{
  */
 
+/** Custom Diffie-Hellman group.
+ *
+ * For keys of type #PSA_KEY_TYPE_DH_PUBLIC_KEY(#PSA_DH_GROUP_CUSTOM) or
+ * #PSA_KEY_TYPE_DH_KEYPAIR(#PSA_DH_GROUP_CUSTOM), the group data comes
+ * from domain parameters set by psa_set_key_domain_parameters().
+ */
+/* This value is reserved for private use in the TLS named group registry. */
+#define PSA_DH_GROUP_CUSTOM             ((psa_dh_group_t) 0x01fc)
+
+
 /**
  * \brief Set domain parameters for a key.
  *
@@ -475,8 +485,9 @@
  *      g       INTEGER
  *   }
  *   ```
- * - For Diffie-Hellman key exchange keys (#PSA_KEY_TYPE_DH_PUBLIC_KEY or
- *   #PSA_KEY_TYPE_DH_KEYPAIR), the
+ * - For Diffie-Hellman key exchange keys
+ *   (#PSA_KEY_TYPE_DH_PUBLIC_KEY(#PSA_DH_GROUP_CUSTOM) or
+ *   #PSA_KEY_TYPE_DH_KEYPAIR(#PSA_DH_GROUP_CUSTOM)), the
  *   `DomainParameters` format as defined by RFC 3279 §2.3.3.
  *   ```
  *   DomainParameters ::= SEQUENCE {