if (cfg.proxy_type == PROXY_HTTP) {
ret->negotiate = proxy_http_negotiate;
} else if (cfg.proxy_type == PROXY_SOCKS) {
- ret->negotiate = proxy_socks_negotiate;
+ if (cfg.proxy_socks_version == 4)
+ ret->negotiate = proxy_socks4_negotiate;
+ else
+ ret->negotiate = proxy_socks5_negotiate;
} else if (cfg.proxy_type == PROXY_TELNET) {
ret->negotiate = proxy_telnet_negotiate;
} else {
sk_write(p->sub_socket, buf, strlen(buf));
p->state = 1;
-
return 0;
}
plug_closing(p->plug, "Network error: Unexpected proxy error",
PROXY_ERROR_UNEXPECTED, 0);
- return 0;
+ return 1;
}
/* ----------------------------------------------------------------------
- * SOCKS proxy type (as yet unimplemented).
+ * SOCKS proxy type.
*/
-int proxy_socks_negotiate (Proxy_Socket p, int change)
+/* SOCKS version 4 */
+int proxy_socks4_negotiate (Proxy_Socket p, int change)
{
- p->error = "Network error: SOCKS proxy implementation is incomplete";
- return 0;
+ if (p->state == PROXY_CHANGE_NEW) {
+
+ /* request format:
+ * version number (1 byte) = 4
+ * command code (1 byte)
+ * 1 = CONNECT
+ * 2 = BIND
+ * dest. port (2 bytes) [network order]
+ * dest. address (4 bytes)
+ * user ID (variable length, null terminated string)
+ */
+
+ int length;
+ char * command;
+
+ if (sk_addrtype(p->remote_addr) != AF_INET) {
+ plug_closing(p->plug, "Network error: SOCKS version 4 does not support IPv6",
+ PROXY_ERROR_GENERAL, 0);
+ return 1;
+ }
+
+ length = strlen(cfg.proxy_username) + 9;
+ command = (char*) malloc(length);
+ strcpy(command + 8, cfg.proxy_username);
+
+ command[0] = 4; /* version 4 */
+ command[1] = 1; /* CONNECT command */
+
+ /* port */
+ command[2] = (char) (p->remote_port >> 8) & 0xff;
+ command[3] = (char) p->remote_port & 0xff;
+
+ /* address */
+ sk_addrcopy(p->remote_addr, command + 4);
+
+ sk_write(p->sub_socket, command, length);
+ free(command);
+
+ p->state = 1;
+ return 0;
+ }
+
+ if (change == PROXY_CHANGE_CLOSING) {
+ /* if our proxy negotiation process involves closing and opening
+ * new sockets, then we would want to intercept this closing
+ * callback when we were expecting it. if we aren't anticipating
+ * a socket close, then some error must have occurred. we'll
+ * just pass those errors up to the backend.
+ */
+ return plug_closing(p->plug, p->closing_error_msg,
+ p->closing_error_code,
+ p->closing_calling_back);
+ }
+
+ if (change == PROXY_CHANGE_SENT) {
+ /* some (or all) of what we wrote to the proxy was sent.
+ * we don't do anything new, however, until we receive the
+ * proxy's response. we might want to set a timer so we can
+ * timeout the proxy negotiation after a while...
+ */
+ return 0;
+ }
+
+ if (change == PROXY_CHANGE_ACCEPTING) {
+ /* we should _never_ see this, as we are using our socket to
+ * connect to a proxy, not accepting inbound connections.
+ * what should we do? close the socket with an appropriate
+ * error message?
+ */
+ return plug_accepting(p->plug, p->accepting_sock);
+ }
+
+ if (change == PROXY_CHANGE_RECEIVE) {
+ /* we have received data from the underlying socket, which
+ * we'll need to parse, process, and respond to appropriately.
+ */
+
+ if (p->state == 1) {
+ /* response format:
+ * version number (1 byte) = 4
+ * reply code (1 byte)
+ * 90 = request granted
+ * 91 = request rejected or failed
+ * 92 = request rejected due to lack of IDENTD on client
+ * 93 = request rejected due to difference in user ID
+ * (what we sent vs. what IDENTD said)
+ * dest. port (2 bytes)
+ * dest. address (4 bytes)
+ */
+
+ char *data;
+ int len;
+
+ /* get the response */
+ bufchain_prefix(&p->pending_input_data, &data, &len);
+
+ if (data[0] != 0) {
+ plug_closing(p->plug, "Network error: SOCKS proxy responded with "
+ "unexpected reply code version",
+ PROXY_ERROR_GENERAL, 0);
+ return 1;
+ }
+
+ if (data[1] != 90) {
+
+ switch (data[1]) {
+ case 92:
+ plug_closing(p->plug, "Network error: SOCKS server wanted IDENTD on client",
+ PROXY_ERROR_GENERAL, 0);
+ break;
+ case 93:
+ plug_closing(p->plug, "Network error: Username and IDENTD on client don't agree",
+ PROXY_ERROR_GENERAL, 0);
+ break;
+ case 91:
+ default:
+ plug_closing(p->plug, "Network error: Error while communicating with proxy",
+ PROXY_ERROR_GENERAL, 0);
+ break;
+ }
+
+ return 1;
+ }
+
+ /* we're done */
+ proxy_activate(p);
+ /* proxy activate will have dealt with
+ * whatever is left of the buffer */
+ return 1;
+ }
+ }
+
+ plug_closing(p->plug, "Network error: Unexpected proxy error",
+ PROXY_ERROR_UNEXPECTED, 0);
+ return 1;
+}
+
+/* SOCKS version 5 */
+int proxy_socks5_negotiate (Proxy_Socket p, int change)
+{
+ if (p->state == PROXY_CHANGE_NEW) {
+
+ /* initial command:
+ * version number (1 byte) = 5
+ * number of available authentication methods (1 byte)
+ * available authentication methods (1 byte * previous value)
+ * authentication methods:
+ * 0x00 = no authentication
+ * 0x01 = GSSAPI
+ * 0x02 = username/password
+ * 0x03 = CHAP
+ */
+
+ char command[3];
+
+ command[0] = 5; /* version 5 */
+ command[1] = 1; /* TODO: we don't currently support any auth methods */
+ command[2] = 0x00; /* no authentication */
+
+ sk_write(p->sub_socket, command, 3);
+
+ p->state = 1;
+ return 0;
+ }
+
+ if (change == PROXY_CHANGE_CLOSING) {
+ /* if our proxy negotiation process involves closing and opening
+ * new sockets, then we would want to intercept this closing
+ * callback when we were expecting it. if we aren't anticipating
+ * a socket close, then some error must have occurred. we'll
+ * just pass those errors up to the backend.
+ */
+ return plug_closing(p->plug, p->closing_error_msg,
+ p->closing_error_code,
+ p->closing_calling_back);
+ }
+
+ if (change == PROXY_CHANGE_SENT) {
+ /* some (or all) of what we wrote to the proxy was sent.
+ * we don't do anything new, however, until we receive the
+ * proxy's response. we might want to set a timer so we can
+ * timeout the proxy negotiation after a while...
+ */
+ return 0;
+ }
+
+ if (change == PROXY_CHANGE_ACCEPTING) {
+ /* we should _never_ see this, as we are using our socket to
+ * connect to a proxy, not accepting inbound connections.
+ * what should we do? close the socket with an appropriate
+ * error message?
+ */
+ return plug_accepting(p->plug, p->accepting_sock);
+ }
+
+ if (change == PROXY_CHANGE_RECEIVE) {
+ /* we have received data from the underlying socket, which
+ * we'll need to parse, process, and respond to appropriately.
+ */
+
+ char *data;
+ int len;
+
+ if (p->state == 1) {
+
+ /* initial response:
+ * version number (1 byte) = 5
+ * authentication method (1 byte)
+ * authentication methods:
+ * 0x00 = no authentication
+ * 0x01 = GSSAPI
+ * 0x02 = username/password
+ * 0x03 = CHAP
+ * 0xff = no acceptable methods
+ */
+
+ /* get the response */
+ bufchain_prefix(&p->pending_input_data, &data, &len);
+
+ if (data[0] != 5) {
+ plug_closing(p->plug, "Network error: Error while communicating with proxy",
+ PROXY_ERROR_GENERAL, 0);
+ return 1;
+ }
+
+ if (data[1] == 0x00) p->state = 2; /* no authentication needed */
+ else if (data[1] == 0x01) p->state = 4; /* GSSAPI authentication */
+ else if (data[1] == 0x02) p->state = 5; /* username/password authentication */
+ else if (data[1] == 0x03) p->state = 6; /* CHAP authentication */
+ else {
+ plug_closing(p->plug, "Network error: We don't support any of the SOCKS "
+ "server's authentication methods",
+ PROXY_ERROR_GENERAL, 0);
+ return 1;
+ }
+ }
+
+ if (p->state == 2) {
+
+ /* request format:
+ * version number (1 byte) = 5
+ * command code (1 byte)
+ * 1 = CONNECT
+ * 2 = BIND
+ * 3 = UDP ASSOCIATE
+ * reserved (1 byte) = 0x00
+ * address type (1 byte)
+ * 1 = IPv4
+ * 3 = domainname (first byte has length, no terminating null)
+ * 4 = IPv6
+ * dest. address (variable)
+ * dest. port (2 bytes) [network order]
+ */
+
+ char command[22];
+ int len;
+
+ if (sk_addrtype(p->remote_addr) == AF_INET) {
+ len = 10;
+ command[3] = 1; /* IPv4 */
+ } else {
+ len = 22;
+ command[3] = 4; /* IPv6 */
+ }
+
+ command[0] = 5; /* version 5 */
+ command[1] = 1; /* CONNECT command */
+ command[2] = 0x00;
+
+ /* address */
+ sk_addrcopy(p->remote_addr, command+4);
+
+ /* port */
+ command[len-2] = (char) (p->remote_port >> 8) & 0xff;
+ command[len-1] = (char) p->remote_port & 0xff;
+
+ sk_write(p->sub_socket, command, len);
+
+ p->state = 3;
+ return 1;
+ }
+
+ if (p->state == 3) {
+
+ /* reply format:
+ * version number (1 bytes) = 5
+ * reply code (1 byte)
+ * 0 = succeeded
+ * 1 = general SOCKS server failure
+ * 2 = connection not allowed by ruleset
+ * 3 = network unreachable
+ * 4 = host unreachable
+ * 5 = connection refused
+ * 6 = TTL expired
+ * 7 = command not supported
+ * 8 = address type not supported
+ * reserved (1 byte) = x00
+ * address type (1 byte)
+ * 1 = IPv4
+ * 3 = domainname (first byte has length, no terminating null)
+ * 4 = IPv6
+ * server bound address (variable)
+ * server bound port (2 bytes) [network order]
+ */
+
+ /* get the response */
+ bufchain_prefix(&p->pending_input_data, &data, &len);
+
+ if (data[0] != 5) {
+ plug_closing(p->plug, "Network error: Error while communicating with proxy",
+ PROXY_ERROR_GENERAL, 0);
+ return 1;
+ }
+
+ if (data[1] != 0) {
+
+ switch (data[1]) {
+ case 1:
+ case 2:
+ case 3:
+ case 4:
+ case 5:
+ case 6:
+ case 7:
+ case 8:
+ default:
+ plug_closing(p->plug, "Network error: Error while communicating with proxy",
+ PROXY_ERROR_GENERAL, 0);
+ break;
+ }
+
+ return 1;
+ }
+
+ /* we're done */
+ proxy_activate(p);
+ /* proxy activate will have dealt with
+ * whatever is left of the buffer */
+ return 1;
+ }
+
+ if (p->state == 4) {
+ /* TODO: Handle GSSAPI authentication */
+ plug_closing(p->plug, "Network error: We don't support GSSAPI authentication",
+ PROXY_ERROR_GENERAL, 0);
+ return 1;
+ }
+
+ if (p->state == 5) {
+ /* TODO: Handle username/password authentication */
+ plug_closing(p->plug, "Network error: We don't support username/password "
+ "authentication",
+ PROXY_ERROR_GENERAL, 0);
+ return 1;
+ }
+
+ if (p->state == 6) {
+ /* TODO: Handle CHAP authentication */
+ plug_closing(p->plug, "Network error: We don't support CHAP authentication",
+ PROXY_ERROR_GENERAL, 0);
+ return 1;
+ }
+ }
+
+ plug_closing(p->plug, "Network error: Unexpected proxy error",
+ PROXY_ERROR_UNEXPECTED, 0);
+ return 1;
}
/* ----------------------------------------------------------------------
}
p->state = 1;
-
return 0;
}
plug_closing(p->plug, "Network error: Unexpected proxy error",
PROXY_ERROR_UNEXPECTED, 0);
- return 0;
+ return 1;
}
projects / u / mdw / putty / commitdiff