From: Guido Vranken Date: Fri, 16 Jun 2017 00:58:56 +0000 (+0200) Subject: Fix a null-pointer dereference in establish_http_proxy_passthru() X-Git-Tag: v2.5_beta1~677 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=14865773ad64d861128bc80ad44c37bdc307c996;p=thirdparty%2Fopenvpn.git Fix a null-pointer dereference in establish_http_proxy_passthru() Prevents that the client crashes if the peer does not specify the 'realm' and/or 'nonce' values. These pointers are dereferenced in DigestCalcHA1() and DigestCalcResponse(); hence, if not set, a null-pointer dereference would occur. Signed-off-by: Guido Vranken Acked-by: Gert Doering Message-Id: <1497574736-2092-1-git-send-email-gv@guidovranken.nl> URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg14844.html Signed-off-by: Gert Doering --- diff --git a/src/openvpn/proxy.c b/src/openvpn/proxy.c index 05f362dc2..46cb2bb03 100644 --- a/src/openvpn/proxy.c +++ b/src/openvpn/proxy.c @@ -875,6 +875,13 @@ establish_http_proxy_passthru(struct http_proxy_info *p, const char *algor = get_pa_var("algorithm", pa, &gc); const char *opaque = get_pa_var("opaque", pa, &gc); + if ( !realm || !nonce ) + { + msg(D_LINK_ERRORS, "HTTP proxy: digest auth failed, malformed response " + "from server: realm= or nonce= missing" ); + goto error; + } + /* generate a client nonce */ ASSERT(rand_bytes(cnonce_raw, sizeof(cnonce_raw))); cnonce = make_base64_string2(cnonce_raw, sizeof(cnonce_raw), &gc);