From 15952814d837cc5687230861d1defed0458ce0aa Mon Sep 17 00:00:00 2001 From: Hanno Becker Date: Thu, 4 Jun 2020 13:31:46 +0100 Subject: [PATCH] Improve documentation of nonce-generating function in ssl_msg.c Signed-off-by: Hanno Becker --- library/ssl_msg.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/library/ssl_msg.c b/library/ssl_msg.c index 65eab4b40..32bbc97be 100644 --- a/library/ssl_msg.c +++ b/library/ssl_msg.c @@ -557,8 +557,14 @@ static int ssl_transform_aead_dynamic_iv_is_explicit( * a) Fixed and dynamic IV lengths add up to total IV length, giving * IV = fixed_iv || dynamic_iv * + * This variant is used in TLS 1.2 when used with GCM or CCM. + * * b) Fixed IV lengths matches total IV length, giving * IV = fixed_iv XOR ( 0 || dynamic_iv ) + * + * This variant occurs in TLS 1.3 and for TLS 1.2 when using ChaChaPoly. + * + * See also the documentation of mbedtls_ssl_transform. */ static void ssl_build_record_nonce( unsigned char *dst_iv, size_t dst_iv_len,