Update ccm.h
Updated return values for mbedtls_ccm_auth_decrypt().
@@ -145,8 +145,9 @@ int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
* \param tag_len The length of the tag in Bytes.
* 4, 6, 8, 10, 12, 14 or 16.
*
- * \return \c 0 on success.
- * \return A CCM or cipher-specific error code on failure.
+ * \return \c 0 on success. This indicates that the message is authentic.
+ * \return #MBEDTLS_ERR_CCM_AUTH_FAILED if the tag does not match.
+ * \return A cipher-specific error code on calculation failure.
*/
int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
const unsigned char *iv, size_t iv_len,
