Add ecdsa_write_signature_det()
diff --git a/library/ecdsa.c b/library/ecdsa.c
index 0bd0e97..e2b6a77 100644
--- a/library/ecdsa.c
+++ b/library/ecdsa.c
@@ -372,25 +372,16 @@
#define MAX_SIG_LEN ( 3 + 2 * ( 2 + POLARSSL_ECP_MAX_BYTES ) )
/*
- * Compute and write signature
+ * Convert a signature (given by context) to ASN.1
*/
-int ecdsa_write_signature( ecdsa_context *ctx,
- const unsigned char *hash, size_t hlen,
- unsigned char *sig, size_t *slen,
- int (*f_rng)(void *, unsigned char *, size_t),
- void *p_rng )
+static int ecdsa_signature_to_asn1( ecdsa_context *ctx,
+ unsigned char *sig, size_t *slen )
{
int ret;
unsigned char buf[MAX_SIG_LEN];
unsigned char *p = buf + sizeof( buf );
size_t len = 0;
- if( ( ret = ecdsa_sign( &ctx->grp, &ctx->r, &ctx->s, &ctx->d,
- hash, hlen, f_rng, p_rng ) ) != 0 )
- {
- return( ret );
- }
-
ASN1_CHK_ADD( len, asn1_write_mpi( &p, buf, &ctx->s ) );
ASN1_CHK_ADD( len, asn1_write_mpi( &p, buf, &ctx->r ) );
@@ -405,6 +396,45 @@
}
/*
+ * Compute and write signature
+ */
+int ecdsa_write_signature( ecdsa_context *ctx,
+ const unsigned char *hash, size_t hlen,
+ unsigned char *sig, size_t *slen,
+ int (*f_rng)(void *, unsigned char *, size_t),
+ void *p_rng )
+{
+ int ret;
+
+ if( ( ret = ecdsa_sign( &ctx->grp, &ctx->r, &ctx->s, &ctx->d,
+ hash, hlen, f_rng, p_rng ) ) != 0 )
+ {
+ return( ret );
+ }
+
+ return( ecdsa_signature_to_asn1( ctx, sig, slen ) );
+}
+
+/*
+ * Compute and write signature deterministically
+ */
+int ecdsa_write_signature_det( ecdsa_context *ctx,
+ const unsigned char *hash, size_t hlen,
+ unsigned char *sig, size_t *slen,
+ md_type_t md_alg )
+{
+ int ret;
+
+ if( ( ret = ecdsa_sign_det( &ctx->grp, &ctx->r, &ctx->s, &ctx->d,
+ hash, hlen, md_alg ) ) != 0 )
+ {
+ return( ret );
+ }
+
+ return( ecdsa_signature_to_asn1( ctx, sig, slen ) );
+}
+
+/*
* Read and check signature
*/
int ecdsa_read_signature( ecdsa_context *ctx,