#include <windows.h>
+#include <assert.h>
+
#define DEFINE_PLUG_METHOD_MACROS
#include "putty.h"
#include "network.h"
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 {
- ret->error = "Network error: Unknown proxy method";
+ ret->error = "Proxy error: Unknown proxy method";
return (Socket) ret;
}
sk_getaddr(p->remote_addr, dest, 64);
- sprintf(buf, "CONNECT %s:%i HTTP/1.1\r\nHost: %s:%i\r\n\r\n",
+ sprintf(buf, "CONNECT %s:%i HTTP/1.1\r\nHost: %s:%i\r\n",
dest, p->remote_port, dest, p->remote_port);
sk_write(p->sub_socket, buf, strlen(buf));
- p->state = 1;
+ if (cfg.proxy_username[0] || cfg.proxy_password[0]) {
+ char buf[sizeof(cfg.proxy_username)+sizeof(cfg.proxy_password)];
+ char buf2[sizeof(buf)*4/3 + 100];
+ int i, j, len;
+ sprintf(buf, "%s:%s", cfg.proxy_username, cfg.proxy_password);
+ len = strlen(buf);
+ sprintf(buf2, "Proxy-Authorization: basic ");
+ for (i = 0, j = strlen(buf2); i < len; i += 3, j += 4)
+ base64_encode_atom(buf+i, (len-i > 3 ? 3 : len-i), buf2+j);
+ strcpy(buf2+j, "\r\n");
+ sk_write(p->sub_socket, buf2, strlen(buf2));
+ }
+
+ sprintf(buf, "\r\n");
+ sk_write(p->sub_socket, buf, strlen(buf));
+ p->state = 1;
return 0;
}
* we'll need to parse, process, and respond to appropriately.
*/
- void *data;
+ char *data, *datap;
int len;
int eol;
int min_ver, maj_ver, status;
/* get the status line */
- bufchain_prefix(&p->pending_input_data, &data, &len);
+ len = bufchain_size(&p->pending_input_data);
+ assert(len > 0); /* or we wouldn't be here */
+ data = smalloc(len);
+ bufchain_fetch(&p->pending_input_data, data, len);
+
eol = get_line_end(data, len);
- if (eol < 0) return 1;
+ if (eol < 0) {
+ sfree(data);
+ return 1;
+ }
- sscanf((char *)data, "HTTP/%i.%i %i", &maj_ver, &min_ver, &status);
+ status = -1;
+ /* We can't rely on whether the %n incremented the sscanf return */
+ if (sscanf((char *)data, "HTTP/%i.%i %n",
+ &maj_ver, &min_ver, &status) < 2 || status == -1) {
+ plug_closing(p->plug, "Proxy error: HTTP response was absent",
+ PROXY_ERROR_GENERAL, 0);
+ sfree(data);
+ return 1;
+ }
/* remove the status line from the input buffer. */
bufchain_consume(&p->pending_input_data, eol);
-
- /* TODO: we need to support Proxy-Auth headers */
-
- if (status < 200 || status > 299) {
+ if (data[status] != '2') {
/* error */
- /* TODO: return a more specific error message,
- * TODO: based on the status code.
- */
- plug_closing(p->plug, "Network error: Error while communicating with proxy",
- PROXY_ERROR_GENERAL, 0);
+ char buf[1024];
+ data[eol] = '\0';
+ while (eol > status &&
+ (data[eol-1] == '\r' || data[eol-1] == '\n'))
+ data[--eol] = '\0';
+ sprintf(buf, "Proxy error: %.900s",
+ data+status);
+ plug_closing(p->plug, buf, PROXY_ERROR_GENERAL, 0);
+ sfree(data);
return 1;
}
+ sfree(data);
+
p->state = 2;
}
* header of length 2, (ie. just "\r\n")
*/
- bufchain_prefix(&p->pending_input_data, &data, &len);
- eol = get_line_end(data, len);
+ len = bufchain_size(&p->pending_input_data);
+ assert(len > 0); /* or we wouldn't be here */
+ data = smalloc(len);
+ datap = data;
+ bufchain_fetch(&p->pending_input_data, data, len);
+
+ eol = get_line_end(datap, len);
+ if (eol < 0) {
+ sfree(data);
+ return 1;
+ }
while (eol > 2)
{
- /* TODO: Proxy-Auth stuff. in some cases, we will
- * TODO: need to extract information from headers.
- */
bufchain_consume(&p->pending_input_data, eol);
- bufchain_prefix(&p->pending_input_data, &data, &len);
- eol = get_line_end(data, len);
+ datap += eol;
+ eol = get_line_end(datap, len);
}
if (eol == 2) {
proxy_activate(p);
/* proxy activate will have dealt with
* whatever is left of the buffer */
+ sfree(data);
return 1;
}
+ sfree(data);
return 1;
}
}
- plug_closing(p->plug, "Network error: Unexpected proxy error",
+ plug_closing(p->plug, "Proxy 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, "Proxy 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[8];
+
+ if (bufchain_size(&p->pending_input_data) < 8)
+ return 1; /* not got anything yet */
+
+ /* get the response */
+ bufchain_fetch(&p->pending_input_data, data, 8);
+
+ if (data[0] != 0) {
+ plug_closing(p->plug, "Proxy 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, "Proxy error: SOCKS server wanted IDENTD on client",
+ PROXY_ERROR_GENERAL, 0);
+ break;
+ case 93:
+ plug_closing(p->plug, "Proxy error: Username and IDENTD on client don't agree",
+ PROXY_ERROR_GENERAL, 0);
+ break;
+ case 91:
+ default:
+ plug_closing(p->plug, "Proxy error: Error while communicating with proxy",
+ PROXY_ERROR_GENERAL, 0);
+ break;
+ }
+
+ return 1;
+ }
+ bufchain_consume(&p->pending_input_data, 8);
+
+ /* we're done */
+ proxy_activate(p);
+ /* proxy activate will have dealt with
+ * whatever is left of the buffer */
+ return 1;
+ }
+ }
+
+ plug_closing(p->plug, "Proxy 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[4];
+ int len;
+
+ command[0] = 5; /* version 5 */
+ if (cfg.proxy_username[0] || cfg.proxy_password[0]) {
+ command[1] = 2; /* two methods supported: */
+ command[2] = 0x00; /* no authentication */
+ command[3] = 0x02; /* username/password */
+ len = 4;
+ } else {
+ command[1] = 1; /* one methods supported: */
+ command[2] = 0x00; /* no authentication */
+ len = 3;
+ }
+
+ sk_write(p->sub_socket, command, len);
+
+ 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) {
+
+ /* 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
+ */
+ char data[2];
+
+ if (bufchain_size(&p->pending_input_data) < 2)
+ return 1; /* not got anything yet */
+
+ /* get the response */
+ bufchain_fetch(&p->pending_input_data, data, 2);
+
+ if (data[0] != 5) {
+ plug_closing(p->plug, "Proxy error: SOCKS proxy returned unexpected version",
+ 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, "Proxy error: SOCKS proxy did not accept our authentication",
+ PROXY_ERROR_GENERAL, 0);
+ return 1;
+ }
+ bufchain_consume(&p->pending_input_data, 2);
+ }
+
+ if (p->state == 7) {
+
+ /* password authentication reply format:
+ * version number (1 bytes) = 1
+ * reply code (1 byte)
+ * 0 = succeeded
+ * >0 = failed
+ */
+ char data[2];
+
+ if (bufchain_size(&p->pending_input_data) < 2)
+ return 1; /* not got anything yet */
+
+ /* get the response */
+ bufchain_fetch(&p->pending_input_data, data, 2);
+
+ if (data[0] != 1) {
+ plug_closing(p->plug, "Proxy error: SOCKS password "
+ "subnegotiation contained wrong version number",
+ PROXY_ERROR_GENERAL, 0);
+ return 1;
+ }
+
+ if (data[1] != 0) {
+
+ plug_closing(p->plug, "Proxy error: SOCKS proxy refused"
+ " password authentication",
+ PROXY_ERROR_GENERAL, 0);
+ return 1;
+ }
+
+ bufchain_consume(&p->pending_input_data, 2);
+ p->state = 2; /* now proceed as authenticated */
+ }
+
+ 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]
+ */
+ char data[5];
+ int len;
+
+ /* First 5 bytes of packet are enough to tell its length. */
+ if (bufchain_size(&p->pending_input_data) < 5)
+ return 1; /* not got anything yet */
+
+ /* get the response */
+ bufchain_fetch(&p->pending_input_data, data, 5);
+
+ if (data[0] != 5) {
+ plug_closing(p->plug, "Proxy error: SOCKS proxy returned wrong version number",
+ PROXY_ERROR_GENERAL, 0);
+ return 1;
+ }
+
+ if (data[1] != 0) {
+ char buf[256];
+
+ strcpy(buf, "Proxy error: ");
+
+ switch (data[1]) {
+ case 1: strcat(buf, "General SOCKS server failure"); break;
+ case 2: strcat(buf, "Connection not allowed by ruleset"); break;
+ case 3: strcat(buf, "Network unreachable"); break;
+ case 4: strcat(buf, "Host unreachable"); break;
+ case 5: strcat(buf, "Connection refused"); break;
+ case 6: strcat(buf, "TTL expired"); break;
+ case 7: strcat(buf, "Command not supported"); break;
+ case 8: strcat(buf, "Address type not supported"); break;
+ default: sprintf(buf+strlen(buf),
+ "Unrecognised SOCKS error code %d",
+ data[1]);
+ break;
+ }
+ plug_closing(p->plug, buf, PROXY_ERROR_GENERAL, 0);
+
+ return 1;
+ }
+
+ /*
+ * Eat the rest of the reply packet.
+ */
+ len = 6; /* first 4 bytes, last 2 */
+ switch (data[3]) {
+ case 1: len += 4; break; /* IPv4 address */
+ case 4: len += 16; break;/* IPv6 address */
+ case 3: len += (unsigned char)data[4]; break; /* domain name */
+ default:
+ plug_closing(p->plug, "Proxy error: SOCKS proxy returned "
+ "unrecognised address format",
+ PROXY_ERROR_GENERAL, 0);
+ return 1;
+ }
+ if (bufchain_size(&p->pending_input_data) < len)
+ return 1; /* not got whole reply yet */
+ bufchain_consume(&p->pending_input_data, len);
+
+ /* we're done */
+ proxy_activate(p);
+ return 1;
+ }
+
+ if (p->state == 4) {
+ /* TODO: Handle GSSAPI authentication */
+ plug_closing(p->plug, "Proxy error: We don't support GSSAPI authentication",
+ PROXY_ERROR_GENERAL, 0);
+ return 1;
+ }
+
+ if (p->state == 5) {
+ if (cfg.proxy_username[0] || cfg.proxy_password[0]) {
+ char userpwbuf[514];
+ int ulen, plen;
+ ulen = strlen(cfg.proxy_username);
+ if (ulen > 255) ulen = 255; if (ulen < 1) ulen = 1;
+ plen = strlen(cfg.proxy_password);
+ if (plen > 255) plen = 255; if (plen < 1) plen = 1;
+ userpwbuf[0] = 1; /* version number of subnegotiation */
+ userpwbuf[1] = ulen;
+ memcpy(userpwbuf+2, cfg.proxy_username, ulen);
+ userpwbuf[ulen+2] = plen;
+ memcpy(userpwbuf+ulen+3, cfg.proxy_password, plen);
+ sk_write(p->sub_socket, userpwbuf, ulen + plen + 3);
+ p->state = 7;
+ } else
+ plug_closing(p->plug, "Proxy error: Server chose "
+ "username/password authentication but we "
+ "didn't offer it!",
+ PROXY_ERROR_GENERAL, 0);
+ return 1;
+ }
+
+ if (p->state == 6) {
+ /* TODO: Handle CHAP authentication */
+ plug_closing(p->plug, "Proxy error: We don't support CHAP authentication",
+ PROXY_ERROR_GENERAL, 0);
+ return 1;
+ }
+
+ }
+
+ plug_closing(p->plug, "Proxy error: Unexpected proxy error",
+ PROXY_ERROR_UNEXPECTED, 0);
+ return 1;
}
/* ----------------------------------------------------------------------
}
p->state = 1;
-
return 0;
}
return 1;
}
- plug_closing(p->plug, "Network error: Unexpected proxy error",
+ plug_closing(p->plug, "Proxy error: Unexpected proxy error",
PROXY_ERROR_UNEXPECTED, 0);
- return 0;
+ return 1;
}
~mdw / sgt / putty / blobdiff