doc update

diff --git a/lib/crypto-api.c b/lib/crypto-api.c
index 9b6c79c084bb830b24d91c9325fd361f2574916f..a5749c10f60c855af3c11ce2c5798c6d8fa10df6 100644 (file)
--- a/lib/crypto-api.c
+++ b/lib/crypto-api.c
@@ -729,7 +729,9 @@ gnutls_aead_cipher_decrypt(gnutls_aead_cipher_hd_t handle,
  *
  * This function will encrypt the given data using the algorithm
  * specified by the context. The output data will contain the
- * authentication tag.
+ * authentication tag. Each call of this function must be
+ * preceded with a call to gnutls_aead_cipher_set_nonce() with
+ * random nonce.
  *
  * Returns: Zero or a negative error code on error.
  *