struct X11FakeAuth *auth = snew(struct X11FakeAuth);
int i;
+ /*
+ * This function has the job of inventing a set of X11 fake auth
+ * data, and adding it to 'authtree'. We must preserve the
+ * property that for any given actual authorisation attempt, _at
+ * most one_ thing in the tree can possibly match it.
+ *
+ * For MIT-MAGIC-COOKIE-1, that's not too difficult: the match
+ * criterion is simply that the entire cookie is correct, so we
+ * just have to make sure we don't make up two cookies the same.
+ * (Vanishingly unlikely, but we check anyway to be sure, and go
+ * round again inventing a new cookie if add234 tells us the one
+ * we thought of is already in use.)
+ *
+ * For XDM-AUTHORIZATION-1, it's a little more fiddly. The setup
+ * with XA1 is that half the cookie is used as a DES key with
+ * which to CBC-encrypt an assortment of stuff. Happily, the stuff
+ * encrypted _begins_ with the other half of the cookie, and the
+ * IV is always zero, which means that any valid XA1 authorisation
+ * attempt for a given cookie must begin with the same cipher
+ * block, consisting of the DES ECB encryption of the first half
+ * of the cookie using the second half as a key. So we compute
+ * that cipher block here and now, and use it as the sorting key
+ * for distinguishing XA1 entries in the tree.
+ */
+
if (authtype == X11_MIT) {
auth->proto = X11_MIT;
sprintf(auth->datastring + i*2, "%02x",
auth->data[i]);
+ auth->disp = NULL;
+ auth->share_cs = auth->share_chan = NULL;
+
return auth;
}
}
}
-struct X11Display *x11_setup_display(char *display, Conf *conf)
+struct X11Display *x11_setup_display(const char *display, Conf *conf)
{
struct X11Display *disp = snew(struct X11Display);
char *localcopy;
char *colon, *dot, *slash;
char *protocol, *hostname;
- colon = strrchr(localcopy, ':');
+ colon = host_strrchr(localcopy, ':');
if (!colon) {
sfree(disp);
sfree(localcopy);
disp->port = 6000 + disp->displaynum;
disp->addr = name_lookup(disp->hostname, disp->port,
- &disp->realhost, conf, ADDRTYPE_UNSPEC);
+ &disp->realhost, conf, ADDRTYPE_UNSPEC,
+ NULL, NULL);
if ((err = sk_addr_error(disp->addr)) != NULL) {
sk_addr_free(disp->addr);
#define XDM_MAXSKEW 20*60 /* 20 minute clock skew should be OK */
-static char *x11_verify(unsigned long peer_ip, int peer_port,
- tree234 *authtree, char *proto,
- unsigned char *data, int dlen,
- struct X11FakeAuth **auth_ret)
+static const char *x11_verify(unsigned long peer_ip, int peer_port,
+ tree234 *authtree, char *proto,
+ unsigned char *data, int dlen,
+ struct X11FakeAuth **auth_ret)
{
struct X11FakeAuth match_dummy; /* for passing to find234 */
struct X11FakeAuth *auth;
* record that _might_ match.
*/
if (!strcmp(proto, x11_authnames[X11_MIT])) {
+ /*
+ * Just look up the whole cookie that was presented to us,
+ * which x11_authcmp will compare against the cookies we
+ * currently believe in.
+ */
match_dummy.proto = X11_MIT;
match_dummy.datalen = dlen;
match_dummy.data = data;
} else if (!strcmp(proto, x11_authnames[X11_XDM])) {
+ /*
+ * Look up the first cipher block, against the stored first
+ * cipher blocks for the XDM-AUTHORIZATION-1 cookies we
+ * currently know. (See comment in x11_invent_fake_auth.)
+ */
match_dummy.proto = X11_XDM;
match_dummy.xa1_firstblock = data;
} else {
if (data[i] != 0) /* zero padding wrong */
return "XDM-AUTHORIZATION-1 data failed check";
tim = time(NULL);
- if (abs(t - tim) > XDM_MAXSKEW)
+ if (((unsigned long)t - (unsigned long)tim
+ + XDM_MAXSKEW) > 2*XDM_MAXSKEW)
return "XDM-AUTHORIZATION-1 time stamp was too far out";
seen = snew(struct XDMSeen);
seen->time = t;
{
int n;
- n = strcspn(display, ":");
+ n = host_strcspn(display, ":");
if (!display[n])
return 0;
n = strcspn(display, ".");
xconn->auth_protocol[xconn->auth_plen] = '\0'; /* ASCIZ */
+ peer_ip = 0; /* placate optimiser */
if (x11_parse_ip(xconn->peer_addr, &peer_ip))
peer_port = xconn->peer_port;
else
}
assert(auth_matched);
+ /*
+ * If this auth points to a connection-sharing downstream
+ * rather than an X display we know how to connect to
+ * directly, pass it off to the sharing module now.
+ */
+ if (auth_matched->share_cs) {
+ sshfwd_x11_sharing_handover(xconn->c, auth_matched->share_cs,
+ auth_matched->share_chan,
+ xconn->peer_addr, xconn->peer_port,
+ xconn->firstpkt[0],
+ protomajor, protominor, data, len);
+ return 0;
+ }
+
/*
* Now we know we're going to accept the connection, and what
* X display to connect to. Actually connect to it.
*/
+ sshfwd_x11_is_local(xconn->c);
xconn->disp = auth_matched->disp;
xconn->s = new_connection(sk_addr_dup(xconn->disp->addr),
xconn->disp->realhost, xconn->disp->port,
sshfwd_write_eof(xconn->c);
}
}
+
+/*
+ * Utility functions used by connection sharing to convert textual
+ * representations of an X11 auth protocol name + hex cookie into our
+ * usual integer protocol id and binary auth data.
+ */
+int x11_identify_auth_proto(const char *protoname)
+{
+ int protocol;
+
+ for (protocol = 1; protocol < lenof(x11_authnames); protocol++)
+ if (!strcmp(protoname, x11_authnames[protocol]))
+ return protocol;
+ return -1;
+}
+
+void *x11_dehexify(const char *hex, int *outlen)
+{
+ int len, i;
+ unsigned char *ret;
+
+ len = strlen(hex) / 2;
+ ret = snewn(len, unsigned char);
+
+ for (i = 0; i < len; i++) {
+ char bytestr[3];
+ unsigned val = 0;
+ bytestr[0] = hex[2*i];
+ bytestr[1] = hex[2*i+1];
+ bytestr[2] = '\0';
+ sscanf(bytestr, "%x", &val);
+ ret[i] = val;
+ }
+
+ *outlen = len;
+ return ret;
+}
+
/*
* Construct an X11 greeting packet, including making up the right
* authorisation data.
t = time(NULL);
PUT_32BIT_MSB_FIRST(realauthdata+14, t);
- des_encrypt_xdmauth(auth_data + 9, realauthdata, authdatalen);
+ des_encrypt_xdmauth((const unsigned char *)auth_data + 9,
+ realauthdata, authdatalen);
} else {
authdata = realauthdata;
authdatalen = 0;