Make ecdsa_verify() return value more explicit
diff --git a/include/polarssl/ecp.h b/include/polarssl/ecp.h
index 36c6185..ad31bff 100644
--- a/include/polarssl/ecp.h
+++ b/include/polarssl/ecp.h
@@ -34,8 +34,9 @@
*/
#define POLARSSL_ERR_ECP_BAD_INPUT_DATA -0x4F80 /**< Bad input parameters to function. */
#define POLARSSL_ERR_ECP_BUFFER_TOO_SMALL -0x4F00 /**< The buffer is too small to write to. */
-#define POLARSSL_ERR_ECP_GENERIC -0x4E80 /**< Generic ECP error */
+#define POLARSSL_ERR_ECP_GENERIC -0x4E80 /**< Generic ECP error. */
#define POLARSSL_ERR_ECP_FEATURE_UNAVAILABLE -0x4E00 /**< Requested curve not available. */
+#define POLARSSL_ERR_ECP_VERIFY_FAILED -0x4E00 /**< The signature is not valid. */
#ifdef __cplusplus
extern "C" {