From c00dc51636b1fedead1c570aef76b32db6208f44 Mon Sep 17 00:00:00 2001
From: Matthew Jordan <mjordan@digium.com>
Date: Fri, 19 Dec 2014 19:58:50 +0000
Subject: [PATCH] stun: correct attribute string padding to match rfc
When sending the USERNAME attribute in an RTP STUN
response, the implementation in append_attr_string
passed the actual length, instead of padding it up
to a multiple of four bytes as required by the RFC
3489. This change adds separate variables for the
string and padded attributed lengths, and performs
padding correctly.
Reported by: Thomas Arimont
Review: https://reviewboard.asterisk.org/r/4139/
........
Merged revisions 427874 from http://svn.asterisk.org/svn/asterisk/branches/11
git-svn-id: https://origsvn.digium.com/svn/asterisk/certified/branches/11.6@429854 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
main/stun.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/main/stun.c b/main/stun.c
index 3b4d2ad6b1..97306a691b 100644
--- a/main/stun.c
+++ b/main/stun.c
@@ -201,12 +201,15 @@ static int stun_process_attr(struct stun_state *state, struct stun_attr *attr)
/*! \brief append a string to an STUN message */
static void append_attr_string(struct stun_attr **attr, int attrval, const char *s, int *len, int *left)
{
- int size = sizeof(**attr) + strlen(s);
+ int str_length = strlen(s);
+ int attr_length = str_length + ((~(str_length - 1)) & 0x3);
+ int size = sizeof(**attr) + attr_length;
if (*left > size) {
(*attr)->attr = htons(attrval);
- (*attr)->len = htons(strlen(s));
- memcpy((*attr)->value, s, strlen(s));
- (*attr) = (struct stun_attr *)((*attr)->value + strlen(s));
+ (*attr)->len = htons(attr_length);
+ memcpy((*attr)->value, s, str_length);
+ memset((*attr)->value + str_length, 0, attr_length - str_length);
+ (*attr) = (struct stun_attr *)((*attr)->value + attr_length);
*len += size;
*left -= size;
}
--
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