From 1af6a324c3206902f69bd2c9838e94ffb4cee3ae Mon Sep 17 00:00:00 2001 From: Lukas Tribus Date: Thu, 5 Nov 2015 13:59:30 +0100 Subject: [PATCH 02/10] BUG/MINOR: acl: don't use record layer in req_ssl_ver MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The initial record layer version in a SSL handshake may be set to TLSv1.0 or similar for compatibility reasons, this is allowed as per RFC5246 Appendix E.1 [1]. Some implementations are Openssl [2] and NSS [3]. A related issue has been fixed some time ago in commit 57d229747 ("BUG/MINOR: acl: req_ssl_sni fails with SSLv3 record version"). Fix this by using the real client hello version instead of the record layer version. This was reported by Julien Vehent and analyzed by Cyril Bonté. The initial patch is from Julien Vehent as well. This should be backported to stable series, the req_ssl_ver keyword was first introduced in 1.3.16. [1] https://tools.ietf.org/html/rfc5246#appendix-E.1 [2] https://github.com/openssl/openssl/commit/4a1cf50187659e60c5867ecbbc36e37b2605d2c3 [3] https://bugzilla.mozilla.org/show_bug.cgi?id=774547 (cherry picked from commit c93242cab986087f06a4655d14fec18eecb7f5f4) (cherry picked from commit b048a6eb3d9cb518e4a378e20ba2a801afec553c) --- src/payload.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/src/payload.c b/src/payload.c index f62163c..b8f1ca3 100644 --- a/src/payload.c +++ b/src/payload.c @@ -148,21 +148,24 @@ smp_fetch_req_ssl_ver(struct proxy *px, struct session *s, void *l7, unsigned in data = (const unsigned char *)s->req->buf->p; if ((*data >= 0x14 && *data <= 0x17) || (*data == 0xFF)) { /* SSLv3 header format */ - if (bleft < 5) + if (bleft < 11) goto too_short; - version = (data[1] << 16) + data[2]; /* version: major, minor */ + version = (data[1] << 16) + data[2]; /* record layer version: major, minor */ msg_len = (data[3] << 8) + data[4]; /* record length */ /* format introduced with SSLv3 */ if (version < 0x00030000) goto not_ssl; - /* message length between 1 and 2^14 + 2048 */ - if (msg_len < 1 || msg_len > ((1<<14) + 2048)) + /* message length between 6 and 2^14 + 2048 */ + if (msg_len < 6 || msg_len > ((1<<14) + 2048)) goto not_ssl; bleft -= 5; data += 5; + + /* return the client hello client version, not the record layer version */ + version = (data[4] << 16) + data[5]; /* client hello version: major, minor */ } else { /* SSLv2 header format, only supported for hello (msg type 1) */ int rlen, plen, cilen, silen, chlen; -- 2.4.10