commit 35e95ddca469ca6c212b05b42df1527693eec7d7
author Manuel Pégourié-Gonnard <mpg@elzevir.fr> Tue Apr 08 12:17:41 2014 +0200
committer Paul Bakker <p.j.bakker@polarssl.org> Wed Apr 09 15:49:59 2014 +0200
tree 86bf8d569bc1758a2288c76c956fe891ede94d28
parent 1cfc45835f39588f5d6f9170aee93efb13544040

Add special return code for ecdsa length mismatch

library/ecdsa.c

diff --git a/library/ecdsa.c b/library/ecdsa.c
index c9ab62f..6e45f2f 100644
--- a/library/ecdsa.c
+++ b/library/ecdsa.c
@@ -422,11 +422,14 @@
         ( ret = asn1_get_mpi( &p, end, &ctx->s ) ) != 0 )
         return( POLARSSL_ERR_ECP_BAD_INPUT_DATA + ret );
 
-    if( p != end )
-        return( POLARSSL_ERR_ECP_BAD_INPUT_DATA +
-                POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
+    if( ( ret = ecdsa_verify( &ctx->grp, hash, hlen,
+                              &ctx->Q, &ctx->r, &ctx->s ) ) != 0 )
+        return( ret );
 
-    return( ecdsa_verify( &ctx->grp, hash, hlen, &ctx->Q, &ctx->r, &ctx->s ) );
+    if( p != end )
+        return( POLARSSL_ERR_ECP_SIG_LEN_MISMATCH );
+
+    return( 0 );
 }
 
 /*

library/error.c

diff --git a/library/error.c b/library/error.c
index 3cc3aa3..2e6bba6 100644
--- a/library/error.c
+++ b/library/error.c
@@ -245,6 +245,8 @@
             snprintf( buf, buflen, "ECP - Generation of random value, such as (ephemeral) key, failed" );
         if( use_ret == -(POLARSSL_ERR_ECP_INVALID_KEY) )
             snprintf( buf, buflen, "ECP - Invalid private or public key" );
+        if( use_ret == -(POLARSSL_ERR_ECP_SIG_LEN_MISMATCH) )
+            snprintf( buf, buflen, "ECP - Signature is valid but shorter than the user-supplied length" );
 #endif /* POLARSSL_ECP_C */
 
 #if defined(POLARSSL_MD_C)