+/*
+ * Platform-independent bits of X11 forwarding.
+ */
+
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include "putty.h"
#include "ssh.h"
-
-#define GET_32BIT_LSB_FIRST(cp) \
- (((unsigned long)(unsigned char)(cp)[0]) | \
- ((unsigned long)(unsigned char)(cp)[1] << 8) | \
- ((unsigned long)(unsigned char)(cp)[2] << 16) | \
- ((unsigned long)(unsigned char)(cp)[3] << 24))
-
-#define PUT_32BIT_LSB_FIRST(cp, value) ( \
- (cp)[0] = (char)(value), \
- (cp)[1] = (char)((value) >> 8), \
- (cp)[2] = (char)((value) >> 16), \
- (cp)[3] = (char)((value) >> 24) )
-
-#define GET_16BIT_LSB_FIRST(cp) \
- (((unsigned long)(unsigned char)(cp)[0]) | \
- ((unsigned long)(unsigned char)(cp)[1] << 8))
-
-#define PUT_16BIT_LSB_FIRST(cp, value) ( \
- (cp)[0] = (char)(value), \
- (cp)[1] = (char)((value) >> 8) )
-
-#define GET_32BIT_MSB_FIRST(cp) \
- (((unsigned long)(unsigned char)(cp)[0] << 24) | \
- ((unsigned long)(unsigned char)(cp)[1] << 16) | \
- ((unsigned long)(unsigned char)(cp)[2] << 8) | \
- ((unsigned long)(unsigned char)(cp)[3]))
-
-#define PUT_32BIT_MSB_FIRST(cp, value) ( \
- (cp)[0] = (char)((value) >> 24), \
- (cp)[1] = (char)((value) >> 16), \
- (cp)[2] = (char)((value) >> 8), \
- (cp)[3] = (char)(value) )
-
-#define GET_16BIT_MSB_FIRST(cp) \
- (((unsigned long)(unsigned char)(cp)[0] << 8) | \
- ((unsigned long)(unsigned char)(cp)[1]))
-
-#define PUT_16BIT_MSB_FIRST(cp, value) ( \
- (cp)[0] = (char)((value) >> 8), \
- (cp)[1] = (char)(value) )
+#include "tree234.h"
#define GET_16BIT(endian, cp) \
(endian=='B' ? GET_16BIT_MSB_FIRST(cp) : GET_16BIT_LSB_FIRST(cp))
"", "MIT-MAGIC-COOKIE-1", "XDM-AUTHORIZATION-1"
};
+struct XDMSeen {
+ unsigned int time;
+ unsigned char clientid[6];
+};
+
struct X11Auth {
unsigned char fakedata[64], realdata[64];
int fakeproto, realproto;
int fakelen, reallen;
+ tree234 *xdmseen;
};
struct X11Private {
Socket s;
};
+static int xdmseen_cmp(void *a, void *b)
+{
+ struct XDMSeen *sa = a, *sb = b;
+ return sa->time > sb->time ? 1 :
+ sa->time < sb->time ? -1 :
+ memcmp(sa->clientid, sb->clientid, sizeof(sa->clientid));
+}
+
void *x11_invent_auth(char *proto, int protomaxlen,
char *data, int datamaxlen, int proto_id)
{
auth->fakelen = 16;
for (i = 0; i < 16; i++)
auth->fakedata[i] = random_byte();
+ auth->xdmseen = NULL;
} else {
assert(proto_id == X11_XDM);
auth->fakeproto = X11_XDM;
auth->fakelen = 16;
for (i = 0; i < 16; i++)
auth->fakedata[i] = (i == 8 ? 0 : random_byte());
+ auth->xdmseen = newtree234(xdmseen_cmp);
}
/* Now format for the recipient. */
return auth;
}
-void x11_free_auth(void *auth)
+void x11_free_auth(void *authv)
{
+ struct X11Auth *auth = (struct X11Auth *)authv;
+ struct XDMSeen *seen;
+ if (auth->xdmseen != NULL) {
+ while ((seen = delpos234(auth->xdmseen, 0)) != NULL)
+ sfree(seen);
+ freetree234(auth->xdmseen);
+ }
sfree(auth);
}
auth->realdata, &auth->reallen);
}
+#define XDM_MAXSKEW 20*60 /* 20 minute clock skew should be OK */
+
static char *x11_verify(unsigned long peer_ip, int peer_port,
struct X11Auth *auth, char *proto,
unsigned char *data, int dlen)
unsigned long t;
time_t tim;
int i;
+ struct XDMSeen *seen, *ret;
if (dlen != 24)
return "XDM-AUTHORIZATION-1 data was wrong length";
if (data[i] != 0) /* zero padding wrong */
return "XDM-AUTHORIZATION-1 data failed check";
tim = time(NULL);
- if (abs(t - tim) > 20*60) /* 20 minute clock skew should be OK */
+ if (abs(t - tim) > XDM_MAXSKEW)
return "XDM-AUTHORIZATION-1 time stamp was too far out";
+ seen = snew(struct XDMSeen);
+ seen->time = t;
+ memcpy(seen->clientid, data+8, 6);
+ assert(auth->xdmseen != NULL);
+ ret = add234(auth->xdmseen, seen);
+ if (ret != seen) {
+ sfree(seen);
+ return "XDM-AUTHORIZATION-1 data replayed";
+ }
+ /* While we're here, purge entries too old to be replayed. */
+ for (;;) {
+ seen = index234(auth->xdmseen, 0);
+ assert(seen != NULL);
+ if (t - seen->time <= XDM_MAXSKEW)
+ break;
+ sfree(delpos234(auth->xdmseen, 0));
+ }
}
/* implement other protocols here if ever required */
return NULL;
}
+static void x11_log(Plug p, int type, SockAddr addr, int port,
+ const char *error_msg, int error_code)
+{
+ /* We have no interface to the logging module here, so we drop these. */
+}
+
static int x11_closing(Plug plug, const char *error_msg, int error_code,
int calling_back)
{
return atoi(display + n + 1);
}
+/* Find the right display, returns an allocated string */
+char *x11_display(const char *display) {
+ char *ret;
+ if(!display || !*display) {
+ /* try to find platform-specific local display */
+ if((ret = platform_get_x_display())==0)
+ /* plausible default for all platforms */
+ ret = dupstr(":0");
+ } else
+ ret = dupstr(display);
+ if(ret[0] == ':') {
+ /* no transport specified, use whatever we think is best */
+ char *s = dupcat(platform_x11_best_transport, ret, (char *)0);
+ sfree(ret);
+ return s;
+ } else
+ return ret;
+}
+
/*
* Called to set up the raw connection.
*
const char *peeraddr, int peerport, const Config *cfg)
{
static const struct plug_function_table fn_table = {
+ x11_log,
x11_closing,
x11_receive,
x11_sent,
int n, displaynum;
struct X11Private *pr;
+ /* default display */
+ display = x11_display(display);
/*
* Split up display name into host and display-number parts.
*/
n = strcspn(display, ":");
+ assert(n != 0); /* x11_display() promises this */
if (display[n])
displaynum = atoi(display + n + 1);
else
displaynum = 0; /* sensible default */
if (n > sizeof(host) - 1)
n = sizeof(host) - 1;
- if (n > 0) {
- strncpy(host, display, n);
- host[n] = '\0';
+ strncpy(host, display, n);
+ host[n] = '\0';
+ sfree(display);
+
+ if(!strcmp(host, "unix")) {
+ /* use AF_UNIX sockets (doesn't make sense on all platforms) */
+ addr = platform_get_x11_unix_address(displaynum,
+ &dummy_realhost);
+ port = 0; /* to show we are not confused */
} else {
+ port = 6000 + displaynum;
+
/*
- * Local display numbers, particularly on Unix, often omit
- * the display part completely.
+ * Try to find host.
*/
- strcpy(host, "localhost");
+ addr = name_lookup(host, port, &dummy_realhost, cfg, ADDRTYPE_UNSPEC);
+ if ((err = sk_addr_error(addr)) != NULL) {
+ sk_addr_free(addr);
+ return err;
+ }
}
- port = 6000 + displaynum;
-
- /*
- * Try to find host.
- */
- addr = name_lookup(host, port, &dummy_realhost, cfg);
- if ((err = sk_addr_error(addr)) != NULL)
- return err;
-
/*
* Open socket.
*/
pr->c = c;
pr->s = *s = new_connection(addr, dummy_realhost, port,
- 0, 1, 0, (Plug) pr, cfg);
+ 0, 1, 0, 0, (Plug) pr, cfg);
if ((err = sk_socket_error(*s)) != NULL) {
sfree(pr);
return err;
}
sk_set_private_ptr(*s, pr);
- sk_addr_free(addr);
return NULL;
}
char realauthdata[64];
int realauthlen = 0;
int authstrlen = strlen(x11_authnames[pr->auth->realproto]);
- unsigned long ip;
- int port;
+ int buflen;
static const char zeroes[4] = { 0,0,0,0 };
+ void *buf;
if (pr->auth->realproto == X11_MIT) {
assert(pr->auth->reallen <= lenof(realauthdata));
memcpy(realauthdata, pr->auth->realdata, realauthlen);
} else if (pr->auth->realproto == X11_XDM &&
pr->auth->reallen == 16 &&
- sk_getxdmdata(s, &ip, &port)) {
+ ((buf = sk_getxdmdata(s, &buflen))!=0)) {
time_t t;
- realauthlen = 24;
- memset(realauthdata, 0, 24);
+ realauthlen = (buflen+12+7) & ~7;
+ assert(realauthlen <= lenof(realauthdata));
+ memset(realauthdata, 0, realauthlen);
memcpy(realauthdata, pr->auth->realdata, 8);
- PUT_32BIT_MSB_FIRST(realauthdata+8, ip);
- PUT_16BIT_MSB_FIRST(realauthdata+12, port);
+ memcpy(realauthdata+8, buf, buflen);
t = time(NULL);
- PUT_32BIT_MSB_FIRST(realauthdata+14, t);
+ PUT_32BIT_MSB_FIRST(realauthdata+8+buflen, t);
des_encrypt_xdmauth(pr->auth->realdata+9,
- (unsigned char *)realauthdata, 24);
+ (unsigned char *)realauthdata,
+ realauthlen);
+ sfree(buf);
}
/* implement other auth methods here if required */
projects / u / mdw / putty / blobdiff