1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
From d81a1600588b726c2bdccda7efad3cc7a87d6245 Mon Sep 17 00:00:00 2001
From: Viktor Dukhovni <openssl-users@dukhovni.org>
Date: Wed, 30 Dec 2015 22:44:51 -0500
Subject: [PATCH] Better SSLv2 cipher-suite enforcement
Based on patch by: Nimrod Aviram <nimrod.aviram@gmail.com>
CVE-2015-3197
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
---
ssl/s2_srvr.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/ssl/s2_srvr.c b/ssl/s2_srvr.c
index 5e2e0ac..07e9df8 100644
--- a/ssl/s2_srvr.c
+++ b/ssl/s2_srvr.c
@@ -402,7 +402,7 @@ static int get_client_master_key(SSL *s)
}
cp = ssl2_get_cipher_by_char(p);
- if (cp == NULL) {
+ if (cp == NULL || sk_SSL_CIPHER_find(s->session->ciphers, cp) < 0) {
ssl2_return_error(s, SSL2_PE_NO_CIPHER);
SSLerr(SSL_F_GET_CLIENT_MASTER_KEY, SSL_R_NO_CIPHER_MATCH);
return (-1);
@@ -692,8 +692,12 @@ static int get_client_hello(SSL *s)
prio = cs;
allow = cl;
}
+
+ /* Generate list of SSLv2 ciphers shared between client and server */
for (z = 0; z < sk_SSL_CIPHER_num(prio); z++) {
- if (sk_SSL_CIPHER_find(allow, sk_SSL_CIPHER_value(prio, z)) < 0) {
+ const SSL_CIPHER *cp = sk_SSL_CIPHER_value(prio, z);
+ if ((cp->algorithm_ssl & SSL_SSLV2) == 0 ||
+ sk_SSL_CIPHER_find(allow, cp) < 0) {
(void)sk_SSL_CIPHER_delete(prio, z);
z--;
}
@@ -702,6 +706,13 @@ static int get_client_hello(SSL *s)
sk_SSL_CIPHER_free(s->session->ciphers);
s->session->ciphers = prio;
}
+
+ /* Make sure we have at least one cipher in common */
+ if (sk_SSL_CIPHER_num(s->session->ciphers) == 0) {
+ ssl2_return_error(s, SSL2_PE_NO_CIPHER);
+ SSLerr(SSL_F_GET_CLIENT_HELLO, SSL_R_NO_CIPHER_MATCH);
+ return -1;
+ }
/*
* s->session->ciphers should now have a list of ciphers that are on
* both the client and server. This list is ordered by the order the
--
1.9.1
|
