Increase strictness of NULL parameter validity in CCM's doxygen
diff --git a/include/mbedtls/ccm.h b/include/mbedtls/ccm.h
index 20730d8..3f6b8f6 100644
--- a/include/mbedtls/ccm.h
+++ b/include/mbedtls/ccm.h
@@ -112,8 +112,6 @@
*
* \param ctx The CCM context to clear. If this is \c NULL, the function
* has no effect. Otherwise, this must be initialized.
- *
- * \note If ctx is \c NULL, the function has no effect.
*/
void mbedtls_ccm_free( mbedtls_ccm_context *ctx );
@@ -136,7 +134,7 @@
* 15 - \p iv_len.
* \param add The additional data field. If \p add_len is greater than
* zero, \p add must be a readable buffer of at least that
- * length. If `add_len == 0`, this may be \c NULL.
+ * length.
* \param add_len The length of additional data in Bytes.
* This must be less than `2^16 - 2^8`.
* \param input The buffer holding the input data. If \p length is greater
@@ -145,9 +143,8 @@
* \param output The buffer holding the output data. If \p length is greater
* than zero, \p output must be a writable buffer of at least
* that length.
- * \param tag The buffer holding the authentication field. If
- * `tag_len > 0`, then this must be a readable buffer of at
- * least \p tag_len Bytes. Otherwise, this may be \c NULL.
+ * \param tag The buffer holding the authentication field. This must be a
+ * readable buffer of at least \p tag_len Bytes.
* \param tag_len The length of the authentication field to generate in Bytes:
* 4, 6, 8, 10, 12, 14 or 16.
*
@@ -181,9 +178,8 @@
* \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
* or 13. The length L of the message length field is
* 15 - \p iv_len.
- * \param add The additional data field. If \p add_len is greater than
- * zero, \p add must be a readable buffer of at least that
- * length. If `add_len == 0`, this may be \c NULL.
+ * \param add The additional data field. This must be a readable buffer of
+ * at least \p add_len Bytes.
* \param add_len The length of additional data in Bytes.
* This must be less than 2^16 - 2^8.
* \param input The buffer holding the input data. If \p length is greater
@@ -192,9 +188,8 @@
* \param output The buffer holding the output data. If \p length is greater
* than zero, \p output must be a writable buffer of at least
* that length.
- * \param tag The buffer holding the authentication field. If
- * `tag_len > 0`, then this must be a readable buffer of at
- * least \p tag_len Bytes. Otherwise, this may be \c NULL.
+ * \param tag The buffer holding the authentication field. This must be a
+ * readable buffer of at least \p tag_len Bytes.
* \param tag_len The length of the authentication field to generate in Bytes:
* 0, 4, 6, 8, 10, 12, 14 or 16.
*
@@ -222,9 +217,8 @@
* \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
* or 13. The length L of the message length field is
* 15 - \p iv_len.
- * \param add The additional data field. If \p add_len is greater than
- * zero, \p add must be a readable buffer of at least that
- * length. If `add_len == 0`, this may be \c NULL.
+ * \param add The additional data field. This must be a readable buffer
+ * of at least that \p add_len Bytes..
* \param add_len The length of additional data in Bytes.
* This must be less than 2^16 - 2^8.
* \param input The buffer holding the input data. If \p length is greater
@@ -233,9 +227,8 @@
* \param output The buffer holding the output data. If \p length is greater
* than zero, \p output must be a writable buffer of at least
* that length.
- * \param tag The buffer holding the authentication field. If
- * `tag_len > 0`, then this must be a readable buffer of at
- * least \p tag_len Bytes. Otherwise, this may be \c NULL.
+ * \param tag The buffer holding the authentication field. This must be a
+ * readable buffer of at least \p tag_len Bytes.
* \param tag_len The length of the authentication field to generate in Bytes:
* 4, 6, 8, 10, 12, 14 or 16.
*
@@ -266,9 +259,8 @@
* \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
* or 13. The length L of the message length field is
* 15 - \p iv_len.
- * \param add The additional data field. If \p add_len is greater than
- * zero, \p add must be a readable buffer of at least that
- * length. If `add_len == 0`, this may be \c NULL.
+ * \param add The additional data field. This must be a readable buffer of
+ * at least that \p add_len Bytes.
* \param add_len The length of additional data in Bytes.
* This must be less than 2^16 - 2^8.
* \param input The buffer holding the input data. If \p length is greater
@@ -277,9 +269,8 @@
* \param output The buffer holding the output data. If \p length is greater
* than zero, \p output must be a writable buffer of at least
* that length.
- * \param tag The buffer holding the authentication field. If
- * `tag_len > 0`, then this must be a readable buffer of at
- * least \p tag_len Bytes. Otherwise, this may be \c NULL.
+ * \param tag The buffer holding the authentication field. This must be a
+ * readable buffer of at least \p tag_len Bytes.
* \param tag_len The length of the authentication field in Bytes.
* 0, 4, 6, 8, 10, 12, 14 or 16.
*