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Merged revisions 186059 via svnmerge from

Browse Source 
https://origsvn.digium.com/svn/asterisk/branches/1.4

................
  r186059 | tilghman | 2009-04-02 12:09:13 -0500 (Thu, 02 Apr 2009) | 9 lines
  
  Merged revisions 186056 via svnmerge from 
  https://origsvn.digium.com/svn/asterisk/branches/1.2
  
  ........
    r186056 | tilghman | 2009-04-02 12:02:18 -0500 (Thu, 02 Apr 2009) | 2 lines
    
    Fix for AST-2009-003
  ........
................


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@186060 65c4cc65-6c06-0410-ace0-fbb531ad65f3
certified/1.8.6
Tilghman Lesher 16 years ago
parent bab6e401ef
commit 08971ce205
2 changed files with 111 additions and 10 deletions
Show Stats Download Patch File Download Diff File

111
channels/chan_sip.c
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@ -2235,7 +2235,7 @@ static int transmit_response_with_sdp(struct sip_pvt *p, const char *msg, const
static int transmit_response_with_unsupported(struct sip_pvt *p, const char *msg, const struct sip_request *req, const char *unsupported);
static int transmit_response_with_auth(struct sip_pvt *p, const char *msg, const struct sip_request *req, const char *rand, enum xmittype reliable, const char *header, int stale);
static int transmit_response_with_allow(struct sip_pvt *p, const char *msg, const struct sip_request *req, enum xmittype reliable);
static void transmit_fake_auth_response(struct sip_pvt *p, struct sip_request *req, enum xmittype reliable);
static void transmit_fake_auth_response(struct sip_pvt *p, int sipmethod, struct sip_request *req, enum xmittype reliable);
static int transmit_request(struct sip_pvt *p, int sipmethod, int inc, enum xmittype reliable, int newbranch);
static int transmit_request_with_auth(struct sip_pvt *p, int sipmethod, int seqno, enum xmittype reliable, int newbranch);
static int transmit_invite(struct sip_pvt *p, int sipmethod, int sdp, int init);
@ -11906,10 +11906,96 @@ static int cb_extensionstate(char *context, char* exten, int state, void *data)
/*! \brief Send a fake 401 Unauthorized response when the administrator
wants to hide the names of local devices from fishers
*/
static void transmit_fake_auth_response(struct sip_pvt *p, struct sip_request *req, enum xmittype reliable)
static void transmit_fake_auth_response(struct sip_pvt *p, int sipmethod, struct sip_request *req, enum xmittype reliable)
{
/* We have to emulate EXACTLY what we'd get with a good peer
* and a bad password, or else we leak information. */
const char *response = "407 Proxy Authentication Required";
const char *reqheader = "Proxy-Authorization";
const char *respheader = "Proxy-Authenticate";
const char *authtoken;
struct ast_str *buf;
char *c;
/* table of recognised keywords, and their value in the digest */
enum keys { K_NONCE, K_LAST };
struct x {
const char *key;
const char *s;
} *i, keys[] = {
[K_NONCE] = { "nonce=", "" },
[K_LAST] = { NULL, NULL}
};
if (sipmethod == SIP_REGISTER || sipmethod == SIP_SUBSCRIBE) {
response = "401 Unauthorized";
reqheader = "Authorization";
respheader = "WWW-Authenticate";
}
authtoken = get_header(req, reqheader);
if (req->ignore && !ast_strlen_zero(p->randdata) && ast_strlen_zero(authtoken)) {
/* This is a retransmitted invite/register/etc, don't reconstruct authentication
* information */
transmit_response_with_auth(p, response, req, p->randdata, 0, respheader, 0);
/* Schedule auto destroy in 32 seconds (according to RFC 3261) */
sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
return;
} else if (ast_strlen_zero(p->randdata) || ast_strlen_zero(authtoken)) {
/* We have no auth, so issue challenge and request authentication */
ast_string_field_build(p, randdata, "%08lx", ast_random()); /* Create nonce for challenge */
transmit_response_with_auth(p, "401 Unauthorized", req, p->randdata, reliable, "WWW-Authenticate", 0);
transmit_response_with_auth(p, response, req, p->randdata, 0, respheader, 0);
/* Schedule auto destroy in 32 seconds */
sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
return;
}
if (!(buf = ast_str_thread_get(&check_auth_buf, CHECK_AUTH_BUF_INITLEN))) {
transmit_response(p, "403 Forbidden (Bad auth)", &p->initreq);
return;
}
/* Make a copy of the response and parse it */
if (ast_str_set(&buf, 0, "%s", authtoken) == AST_DYNSTR_BUILD_FAILED) {
transmit_response(p, "403 Forbidden (Bad auth)", &p->initreq);
return;
}
c = buf->str;
while (c && *(c = ast_skip_blanks(c))) { /* lookup for keys */
for (i = keys; i->key != NULL; i++) {
const char *separator = ","; /* default */
if (strncasecmp(c, i->key, strlen(i->key)) != 0) {
continue;
}
/* Found. Skip keyword, take text in quotes or up to the separator. */
c += strlen(i->key);
if (*c == '"') { /* in quotes. Skip first and look for last */
c++;
separator = "\"";
}
i->s = c;
strsep(&c, separator);
break;
}
if (i->key == NULL) { /* not found, jump after space or comma */
strsep(&c, " ,");
}
}
/* Verify nonce from request matches our nonce. If not, send 401 with new nonce */
if (strcasecmp(p->randdata, keys[K_NONCE].s)) {
if (!req->ignore) {
ast_string_field_build(p, randdata, "%08lx", ast_random());
}
transmit_response_with_auth(p, response, req, p->randdata, reliable, respheader, FALSE);
/* Schedule auto destroy in 32 seconds */
sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
} else {
transmit_response(p, "403 Forbidden (Bad auth)", &p->initreq);
}
}
/*!
@ -12085,6 +12171,14 @@ static enum check_auth_result register_verify(struct sip_pvt *p, struct sockaddr
}
}
}
if (!peer && sip_cfg.alwaysauthreject) {
/* If we found a peer, we transmit a 100 Trying. Therefore, if we're
* trying to avoid leaking information, we MUST also transmit the same
* response when we DON'T find a peer. */
transmit_response(p, "100 Trying", req);
/* Insert a fake delay between the 100 and the subsequent failure. */
sched_yield();
}
if (!res) {
ast_devstate_changed(AST_DEVICE_UNKNOWN, "SIP/%s", peer->name);
}
@ -12111,7 +12205,12 @@ static enum check_auth_result register_verify(struct sip_pvt *p, struct sockaddr
case AUTH_PEER_NOT_DYNAMIC:
case AUTH_ACL_FAILED:
if (sip_cfg.alwaysauthreject) {
transmit_fake_auth_response(p, &p->initreq, XMIT_UNRELIABLE);
transmit_fake_auth_response(p, SIP_REGISTER, &p->initreq, XMIT_UNRELIABLE);
if (global_authfailureevents) {
manager_event(EVENT_FLAG_SYSTEM, "PeerStatus", "ChannelType: SIP\r\nPeer: SIP/%s\r\nPeerStatus: Rejected\r\nCause: %s\r\nAddress: %s\r\nPort: %d\r\n",
name, res == AUTH_PEER_NOT_DYNAMIC ? "AUTH_PEER_NOT_DYNAMIC" : "URI_NOT_FOUND",
ast_inet_ntoa(sin->sin_addr), ntohs(sin->sin_port));
}
} else {
/* URI not found */
if (res == AUTH_PEER_NOT_DYNAMIC) {
@ -18879,7 +18978,7 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int
if (res < 0) { /* Something failed in authentication */
if (res == AUTH_FAKE_AUTH) {
ast_log(LOG_NOTICE, "Sending fake auth rejection for device %s\n", get_header(req, "From"));
transmit_fake_auth_response(p, req, XMIT_RELIABLE);
transmit_fake_auth_response(p, SIP_INVITE, req, XMIT_RELIABLE);
} else {
ast_log(LOG_NOTICE, "Failed to authenticate device %s\n", get_header(req, "From"));
transmit_response_reliable(p, "403 Forbidden", req);
@ -20076,7 +20175,7 @@ static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req,
if (res < 0) {
if (res == AUTH_FAKE_AUTH) {
ast_log(LOG_NOTICE, "Sending fake auth rejection for device %s\n", get_header(req, "From"));
transmit_fake_auth_response(p, req, XMIT_UNRELIABLE);
transmit_fake_auth_response(p, SIP_SUBSCRIBE, req, XMIT_UNRELIABLE);
} else {
ast_log(LOG_NOTICE, "Failed to authenticate device %s for SUBSCRIBE\n", get_header(req, "From"));
transmit_response_reliable(p, "403 Forbidden", req);

6
configs/sip.conf.sample
Unescape View File

@ -261,9 +261,11 @@ srvlookup=yes ; Enable DNS SRV lookups on outbound calls
;authfailureevents=no ; generate manager "peerstatus" events when peer can't
; authenticate with Asterisk. Peerstatus will be "rejected".
;alwaysauthreject = yes ; When an incoming INVITE or REGISTER is to be rejected,
; for any reason, always reject with '401 Unauthorized'
; for any reason, always reject with an identical response
; equivalent to valid username and invalid password/hash
; instead of letting the requester know whether there was
; a matching user or peer for their request
; a matching user or peer for their request. This reduces
; the ability of an attacker to scan for valid SIP usernames.
;g726nonstandard = yes ; If the peer negotiates G726-32 audio, use AAL2 packing
; order instead of RFC3551 packing order (this is required

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