commit f28c2aa64e0436fbc03c4b9f4c2f59f8d77dfdf8
author Daniel King <damaki.gh@gmail.com> Tue May 17 15:56:26 2016 -0300
committer Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com> Thu May 10 13:20:52 2018 +0200
tree 16d60c60fd6b36b7abe206e4ac0d3973372aa656
parent 31ac12e004dd169f47c2d575abad77fd9fedd4e4

Allow some parameters to be NULL if the length is 0.

This change permits users of the ChaCha20/Poly1305 algorithms
(and the AEAD construction thereof) to pass NULL pointers for
data that they do not need, and avoids the need to provide a valid
buffer for data that is not used.

include/mbedtls/chacha20.h

diff --git a/include/mbedtls/chacha20.h b/include/mbedtls/chacha20.h
index ab87f66..ccce122 100644
--- a/include/mbedtls/chacha20.h
+++ b/include/mbedtls/chacha20.h
@@ -136,7 +136,9 @@
  * \param ctx       The ChaCha20 context.
  * \param size      The length (in bytes) to process. This can have any length.
  * \param input     Buffer containing the input data.
+ *                  This pointer can be NULL if size == 0.
  * \param output    Buffer containing the output data.
+ *                  This pointer can be NULL if size == 0.
  *
  * \return          MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA if the ctx, input, or
  *                  output pointers are NULL.