commit ccdce90adb3438ff094c5a0c0681413a230e28a6
author Jaeden Amero <jaeden@patater.com> Thu Jan 10 11:42:27 2019 +0000
committer Jaeden Amero <jaeden.amero@arm.com> Wed Jan 23 17:39:46 2019 +0000
tree 2ef7e6852ca46953b04c8bb59bfe6327c7dcd289
parent 97271b37c8d008da7a202840f35d22cca785a00c

psa: Simplify EC public key format

Remove front matter from our EC key format, to make it just the contents
of an ECPoint as defined by SEC1 section 2.3.3.

As a consequence of the simplification, remove the restriction on not
being able to use an ECDH key with ECDSA. There is no longer any OID
specified when importing a key, so we can't reject importing of an ECDH
key for the purpose of ECDSA based on the OID.

tests/suites/test_suite_psa_crypto.function

diff --git a/tests/suites/test_suite_psa_crypto.function b/tests/suites/test_suite_psa_crypto.function
index 4d6cefb..ea1e545 100644
--- a/tests/suites/test_suite_psa_crypto.function
+++ b/tests/suites/test_suite_psa_crypto.function
@@ -648,36 +648,12 @@
 #if defined(MBEDTLS_ECP_C)
         if( PSA_KEY_TYPE_IS_ECC_PUBLIC_KEY( type ) )
         {
-            mbedtls_asn1_buf alg;
-            mbedtls_asn1_buf params;
-            mbedtls_asn1_bitstring bitstring;
-            /* SubjectPublicKeyInfo  ::=  SEQUENCE  {
-             *      algorithm          AlgorithmIdentifier,
-             *      subjectPublicKey   BIT STRING  }
-             * AlgorithmIdentifier  ::=  SEQUENCE  {
-             *      algorithm          OBJECT IDENTIFIER,
-             *      parameters         ANY DEFINED BY algorithm OPTIONAL  }
+            /* The representation of an ECC public key is:
+             *      - The byte 0x04;
+             *      - `x_P` as a `ceiling(m/8)`-byte string, big-endian;
+             *      - `y_P` as a `ceiling(m/8)`-byte string, big-endian;
+             *      - where m is the bit size associated with the curve.
              */
-
-            TEST_EQUAL( mbedtls_asn1_get_tag( &p, end, &len,
-                                              MBEDTLS_ASN1_SEQUENCE |
-                                              MBEDTLS_ASN1_CONSTRUCTED ),
-                        0 );
-            TEST_EQUAL( p + len, end );
-            TEST_EQUAL( mbedtls_asn1_get_alg( &p, end, &alg, &params ), 0 );
-            if( ! is_oid_of_key_type( type, alg.p, alg.len ) )
-                goto exit;
-            TEST_EQUAL( mbedtls_asn1_get_bitstring( &p, end, &bitstring ), 0 );
-            TEST_EQUAL( p, end );
-            p = bitstring.p;
-
-            /*   ECPoint ::= ...
-             *      -- first 8 bits: 0x04 (uncompressed representation);
-             *      -- then x_P as an n-bit string, big endian;
-             *      -- then y_P as a n-bit string, big endian,
-             *      -- where n is the order of the curve.
-             */
-            TEST_EQUAL( bitstring.unused_bits, 0 );
             TEST_EQUAL( p + 1 + 2 * PSA_BITS_TO_BYTES( bits ), end );
             TEST_EQUAL( p[0], 4 );
         }