OpenSSL requires a signature length of exactly RSA_size()

2008-11-04 14:05:42 +00:00
parent d4f08fe324
commit 7854475f42
1 changed files with 3 additions and 5 deletions
@@ -90,13 +90,11 @@ static bool verify_emsa_pkcs1_signature(private_openssl_rsa_public_key_t *this,
 		goto error;
 	}
 	
-	/* remove any preceding 0-bytes from signature */
-	while (signature.len && *(signature.ptr) == 0x00)
+	/* VerifyFinal expects a signature of exactly RSA size (no leading 0x00) */
+	if (signature.len > RSA_size(this->rsa))
 	{
-		signature.len -= 1;
-		signature.ptr++;
+		signature = chunk_skip(signature, signature.len - RSA_size(this->rsa));
 	}
-	
 	valid = (EVP_VerifyFinal(ctx, signature.ptr, signature.len, key) == 1);
 	
 error: