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asterisk
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Code Issues Releases Wiki Activity

handle stale authentication nonces more properly (bug #4343, with formatting fixes)

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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@5834 65c4cc65-6c06-0410-ace0-fbb531ad65f3
1.2-netsec
Kevin P. Fleming 21 years ago
parent 860d7948ba
commit 115e45c7b0
1 changed files with 89 additions and 16 deletions
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99
channels/chan_sip.c
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@ -672,7 +672,7 @@ static struct sip_auth *authl; /* Authentication list */
static struct ast_frame *sip_read(struct ast_channel *ast);
static int transmit_response(struct sip_pvt *p, char *msg, struct sip_request *req);
static int transmit_response_with_sdp(struct sip_pvt *p, char *msg, struct sip_request *req, int retrans);
static int transmit_response_with_auth(struct sip_pvt *p, char *msg, struct sip_request *req, char *rand, int reliable, char *header);
static int transmit_response_with_auth(struct sip_pvt *p, char *msg, struct sip_request *req, char *rand, int reliable, char *header, int stale);
static int transmit_request(struct sip_pvt *p, int sipmethod, int inc, int reliable, int newbranch);
static int transmit_request_with_auth(struct sip_pvt *p, int sipmethod, int inc, int reliable, int newbranch);
static int transmit_invite(struct sip_pvt *p, int sipmethod, int sendsdp, char *auth, char *authheader, char *vxml_url, char *distinctive_ring, char *osptoken, int addsipheaders, int init);
@ -3717,7 +3717,7 @@ static int transmit_response_with_allow(struct sip_pvt *p, char *msg, struct sip
}
/* transmit_response_with_auth: Respond with authorization request */
static int transmit_response_with_auth(struct sip_pvt *p, char *msg, struct sip_request *req, char *randdata, int reliable, char *header)
static int transmit_response_with_auth(struct sip_pvt *p, char *msg, struct sip_request *req, char *randdata, int reliable, char *header, int stale)
{
struct sip_request resp;
char tmp[256];
@ -3727,7 +3727,9 @@ static int transmit_response_with_auth(struct sip_pvt *p, char *msg, struct sip_
ast_log(LOG_WARNING, "Unable to determine sequence number from '%s'\n", get_header(req, "CSeq"));
return -1;
}
snprintf(tmp, sizeof(tmp), "Digest realm=\"%s\", nonce=\"%s\"", global_realm, randdata);
/* Stale means that they sent us correct authentication, but
based it on an old challenge (nonce) */
snprintf(tmp, sizeof(tmp), "Digest realm=\"%s\", nonce=\"%s\" %s", global_realm, randdata, stale ? ", stale=true" : "");
respprep(&resp, p, msg, req);
add_header(&resp, header, tmp);
add_header(&resp, "Content-Length", "0");
@ -5338,7 +5340,7 @@ static int check_auth(struct sip_pvt *p, struct sip_request *req, char *randdata
if (!reliable) {
/* Resend message if this was NOT a reliable delivery. Otherwise the
retransmission should get it */
transmit_response_with_auth(p, response, req, randdata, reliable, respheader);
transmit_response_with_auth(p, response, req, randdata, reliable, respheader, 0);
/* Schedule auto destroy in 15 seconds */
sip_scheddestroy(p, 15000);
}
@ -5346,7 +5348,7 @@ static int check_auth(struct sip_pvt *p, struct sip_request *req, char *randdata
}
} else if (ast_strlen_zero(randdata) || ast_strlen_zero(authtoken)) {
snprintf(randdata, randlen, "%08x", rand());
transmit_response_with_auth(p, response, req, randdata, reliable, respheader);
transmit_response_with_auth(p, response, req, randdata, reliable, respheader, 0);
/* Schedule auto destroy in 15 seconds */
sip_scheddestroy(p, 15000);
res = 1;
@ -5362,8 +5364,12 @@ static int check_auth(struct sip_pvt *p, struct sip_request *req, char *randdata
char tmp[256] = "";
char *c;
char *z;
char *response ="";
char *ua_hash ="";
char *resp_uri ="";
char *nonce = "";
char *digestusername = "";
int wrongnonce = 0;
char *usednonce = randdata;
/* Find their response among the mess that we'r sent for comparison */
ast_copy_string(tmp, authtoken, sizeof(tmp));
@ -5376,12 +5382,12 @@ static int check_auth(struct sip_pvt *p, struct sip_request *req, char *randdata
if (!strncasecmp(c, "response=", strlen("response="))) {
c+= strlen("response=");
if ((*c == '\"')) {
response=++c;
ua_hash=++c;
if ((c = strchr(c,'\"')))
*c = '\0';
} else {
response=c;
ua_hash=c;
if ((c = strchr(c,',')))
*c = '\0';
}
@ -5398,32 +5404,86 @@ static int check_auth(struct sip_pvt *p, struct sip_request *req, char *randdata
*c = '\0';
}
} else if (!strncasecmp(c, "username=", strlen("username="))) {
c+= strlen("username=");
if ((*c == '\"')) {
digestusername=++c;
if((c = strchr(c,'\"')))
*c = '\0';
} else {
digestusername=c;
if((c = strchr(c,',')))
*c = '\0';
}
} else if (!strncasecmp(c, "nonce=", strlen("nonce="))) {
c+= strlen("nonce=");
if ((*c == '\"')) {
nonce=++c;
if ((c = strchr(c,'\"')))
*c = '\0';
} else {
nonce=c;
if ((c = strchr(c,',')))
*c = '\0';
}
} else
if ((z = strchr(c,' ')) || (z = strchr(c,','))) c=z;
if (c)
c++;
}
/* Verify that digest username matches the username we auth as */
if (strcmp(username, digestusername)) {
/* Oops, we're trying something here */
return -2;
}
/* Verify nonce from request matches our nonce. If not, send 401 with new nonce */
if (strncasecmp(randdata, nonce, randlen)) {
wrongnonce = 1;
usednonce = nonce;
}
snprintf(a1, sizeof(a1), "%s:%s:%s", username, global_realm, secret);
if (!ast_strlen_zero(resp_uri))
snprintf(a2, sizeof(a2), "%s:%s", sip_methods[sipmethod].text, resp_uri);
else
snprintf(a2, sizeof(a2), "%s:%s", sip_methods[sipmethod].text, uri);
if (!ast_strlen_zero(md5secret))
snprintf(a1_hash, sizeof(a1_hash), "%s", md5secret);
else
ast_md5_hash(a1_hash, a1);
ast_md5_hash(a2_hash, a2);
snprintf(resp, sizeof(resp), "%s:%s:%s", a1_hash, randdata, a2_hash);
snprintf(resp, sizeof(resp), "%s:%s:%s", a1_hash, usednonce, a2_hash);
ast_md5_hash(resp_hash, resp);
/* resp_hash now has the expected response, compare the two */
if (wrongnonce) {
ast_log(LOG_NOTICE, "stale nonce received from '%s'\n", get_header(req, "To"));
snprintf(randdata, randlen, "%08x", rand());
if (ua_hash && !strncasecmp(ua_hash, resp_hash, strlen(resp_hash))) {
/* We got working auth token, based on stale nonce . */
transmit_response_with_auth(p, response, req, randdata, reliable, respheader, 1);
} else {
/* Everything was wrong, so give the device one more try */
transmit_response_with_auth(p, response, req, randdata, reliable, respheader, 0);
}
if (response && !strncasecmp(response, resp_hash, strlen(resp_hash))) {
/* Schedule auto destroy in 15 seconds */
sip_scheddestroy(p, 15000);
return 1;
}
/* resp_hash now has the expected response, compare the two */
if (ua_hash && !strncasecmp(ua_hash, resp_hash, strlen(resp_hash))) {
/* Auth is OK */
res = 0;
}
/* Assume success ;-) */
}
/* Failure */
return res;
}
@ -5524,8 +5584,21 @@ static int register_verify(struct sip_pvt *p, struct sockaddr_in *sin, struct si
if (!res) {
ast_device_state_changed("SIP/%s", peer->name);
}
if (res < 0)
if (res < 0) {
switch (res) {
case -1:
/* Wrong password in authentication. Go away, don't try again until you fixed it */
transmit_response(p, "403 Forbidden", &p->initreq);
break;
case -2:
/* Username and digest username does not match.
Asterisk uses the From: username for authentication. We need the
users to use the same authentication user name until we support
proper authentication by digest auth name */
transmit_response(p, "403 Authentication user name does not match account name", &p->initreq);
break;
}
}
if (peer)
ASTOBJ_UNREF(peer,sip_destroy_peer);
return res;

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