Add ECDSA verify
Add tests for external verification when signing is done both internally and externally
diff --git a/library/ecdsa.c b/library/ecdsa.c
index fdd0afb..645fbb5 100644
--- a/library/ecdsa.c
+++ b/library/ecdsa.c
@@ -287,9 +287,70 @@
#endif /* MBEDTLS_ECDSA_VERIFY_ALT */
/*
+ * Convert a signature to a raw concatenation of {r, s}
+ */
+int mbedtls_ecdsa_signature_to_raw( const unsigned char *sig,
+ size_t ssize, uint16_t byte_len,
+ unsigned char *buf, size_t* slen )
+{
+ int ret;
+ unsigned char *p = (unsigned char *) sig;
+ const unsigned char *end = sig + ssize;
+ size_t len;
+ mbedtls_mpi r, s;
+
+ if( 2 * byte_len > ssize )
+ {
+ return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
+ }
+
+ mbedtls_mpi_init( &r );
+ mbedtls_mpi_init( &s );
+
+ if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
+ MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
+ {
+ ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
+ goto cleanup;
+ }
+
+ if( p + len != end )
+ {
+ ret = MBEDTLS_ERR_ECP_BAD_INPUT_DATA +
+ MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
+ goto cleanup;
+ }
+
+ if( ( ret = mbedtls_asn1_get_mpi( &p, end, &r ) ) != 0 ||
+ ( ret = mbedtls_asn1_get_mpi( &p, end, &s ) ) != 0 )
+ {
+ ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
+ goto cleanup;
+ }
+ p = (unsigned char *) buf;
+ if( ( ret = mbedtls_mpi_write_binary(&r, p, byte_len) ) )
+ {
+ ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
+ goto cleanup;
+ }
+ p += byte_len;
+ if( ( ret = mbedtls_mpi_write_binary(&s, p, byte_len) ) )
+ {
+ ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
+ goto cleanup;
+ }
+ *slen = 2*byte_len;
+ cleanup:
+ mbedtls_mpi_free( &r );
+ mbedtls_mpi_free( &s );
+
+ return( ret );
+}
+
+/*
* Convert a signature (given by context) to ASN.1
*/
-int ecdsa_signature_to_asn1( const mbedtls_mpi *r, const mbedtls_mpi *s,
+int mbedtls_ecdsa_signature_to_asn1( const mbedtls_mpi *r, const mbedtls_mpi *s,
unsigned char *sig, size_t *slen, size_t ssize )
{
int ret;
@@ -339,7 +400,7 @@
hash, hlen, f_rng, p_rng ) );
#endif
- MBEDTLS_MPI_CHK( ecdsa_signature_to_asn1( &r, &s, sig, slen, ssize ) );
+ MBEDTLS_MPI_CHK( mbedtls_ecdsa_signature_to_asn1( &r, &s, sig, slen, ssize ) );
cleanup:
mbedtls_mpi_free( &r );