Implement and test mbedtls_ecp_write_key
mbedtls_ecp_write_key is a mirror function to mbedtls_ecp_read_key, which
writes a private key back into a byte buffer in the correct format.
This is a helpful convenience function, since the byte order is defined
differently between Montgomery and Weierstrass curves. Since this difference
is accounted for in mbedtls_ecp_read_key, it made sense to add
mbedtls_ecp_write_key for the purpose of abstracting this away such that
psa_export_key doesn't need to take byte order into account.
Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
diff --git a/tests/suites/test_suite_ecp.function b/tests/suites/test_suite_ecp.function
index 03c3e53..1a464ec 100644
--- a/tests/suites/test_suite_ecp.function
+++ b/tests/suites/test_suite_ecp.function
@@ -1069,12 +1069,14 @@
/* END_CASE */
/* BEGIN_CASE */
-void mbedtls_ecp_read_key( int grp_id, data_t* in_key, int expected )
+void mbedtls_ecp_read_key( int grp_id, data_t* in_key, int expected, int canonical )
{
int ret = 0;
mbedtls_ecp_keypair key;
+ mbedtls_ecp_keypair key2;
mbedtls_ecp_keypair_init( &key );
+ mbedtls_ecp_keypair_init( &key2 );
ret = mbedtls_ecp_read_key( grp_id, &key, in_key->x, in_key->len );
TEST_ASSERT( ret == expected );
@@ -1083,10 +1085,52 @@
{
ret = mbedtls_ecp_check_privkey( &key.grp, &key.d );
TEST_ASSERT( ret == 0 );
+
+ if( canonical )
+ {
+ unsigned char buf[MBEDTLS_ECP_MAX_BYTES];
+ size_t olen;
+
+ ret = mbedtls_ecp_write_key( grp_id, &key, &olen, buf, in_key->len );
+ TEST_ASSERT( ret == 0 );
+
+ TEST_ASSERT( olen == in_key->len );
+
+ mbedtls_fprintf( stdout, "written key: ");
+ for( size_t i = 0; i < in_key->len; i++ ) {
+ mbedtls_fprintf( stdout, "%02x", buf[i]);
+ }
+ mbedtls_fprintf( stdout, "\n");
+ ASSERT_COMPARE( in_key->x, in_key->len,
+ buf, olen );
+ }
+ else
+ {
+ unsigned char export1[MBEDTLS_ECP_MAX_BYTES];
+ size_t olen1;
+
+ unsigned char export2[MBEDTLS_ECP_MAX_BYTES];
+ size_t olen2;
+
+ ret = mbedtls_ecp_write_key( grp_id, &key, &olen1, export1, in_key->len );
+ TEST_ASSERT( ret == 0 );
+
+ ret = mbedtls_ecp_read_key( grp_id, &key2, export1, in_key->len );
+ TEST_ASSERT( ret == expected );
+
+ ret = mbedtls_ecp_write_key( grp_id, &key2, &olen2, export2, in_key->len );
+ TEST_ASSERT( ret == 0 );
+
+ TEST_ASSERT( olen2 == olen1 );
+
+ ASSERT_COMPARE( export1, olen1,
+ export2, olen2 );
+ }
}
exit:
mbedtls_ecp_keypair_free( &key );
+ mbedtls_ecp_keypair_free( &key2 );
}
/* END_CASE */