Annotation of src/usr.bin/nc/socks.c, Revision 1.26
1.26 ! inoguchi 1: /* $OpenBSD: socks.c,v 1.25 2018/03/27 16:31:10 deraadt Exp $ */
1.1 jakob 2:
3: /*
4: * Copyright (c) 1999 Niklas Hallqvist. All rights reserved.
1.14 djm 5: * Copyright (c) 2004, 2005 Damien Miller. All rights reserved.
1.1 jakob 6: *
7: * Redistribution and use in source and binary forms, with or without
8: * modification, are permitted provided that the following conditions
9: * are met:
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: * 2. Redistributions in binary form must reproduce the above copyright
13: * notice, this list of conditions and the following disclaimer in the
14: * documentation and/or other materials provided with the distribution.
15: *
16: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26: */
27:
28: #include <sys/types.h>
29: #include <sys/socket.h>
30: #include <netinet/in.h>
31: #include <arpa/inet.h>
32:
33: #include <err.h>
1.9 djm 34: #include <errno.h>
1.1 jakob 35: #include <netdb.h>
36: #include <stdio.h>
37: #include <stdlib.h>
38: #include <string.h>
1.26 ! inoguchi 39: #include <strings.h>
1.1 jakob 40: #include <unistd.h>
1.16 djm 41: #include <resolv.h>
42: #include <readpassphrase.h>
1.15 avsm 43: #include "atomicio.h"
1.1 jakob 44:
45: #define SOCKS_PORT "1080"
1.9 djm 46: #define HTTP_PROXY_PORT "3128"
47: #define HTTP_MAXHDRS 64
1.5 markus 48: #define SOCKS_V5 5
49: #define SOCKS_V4 4
1.1 jakob 50: #define SOCKS_NOAUTH 0
51: #define SOCKS_NOMETHOD 0xff
52: #define SOCKS_CONNECT 1
53: #define SOCKS_IPV4 1
1.14 djm 54: #define SOCKS_DOMAIN 3
55: #define SOCKS_IPV6 4
1.9 djm 56:
1.10 otto 57: int remote_connect(const char *, const char *, struct addrinfo);
1.16 djm 58: int socks_connect(const char *, const char *, struct addrinfo,
59: const char *, const char *, struct addrinfo, int,
60: const char *);
1.1 jakob 61:
1.14 djm 62: static int
63: decode_addrport(const char *h, const char *p, struct sockaddr *addr,
64: socklen_t addrlen, int v4only, int numeric)
1.1 jakob 65: {
1.14 djm 66: int r;
67: struct addrinfo hints, *res;
1.1 jakob 68:
1.14 djm 69: bzero(&hints, sizeof(hints));
70: hints.ai_family = v4only ? PF_INET : PF_UNSPEC;
71: hints.ai_flags = numeric ? AI_NUMERICHOST : 0;
72: hints.ai_socktype = SOCK_STREAM;
73: r = getaddrinfo(h, p, &hints, &res);
74: /* Don't fatal when attempting to convert a numeric address */
75: if (r != 0) {
76: if (!numeric) {
77: errx(1, "getaddrinfo(\"%.64s\", \"%.64s\"): %s", h, p,
78: gai_strerror(r));
79: }
80: return (-1);
81: }
82: if (addrlen < res->ai_addrlen) {
83: freeaddrinfo(res);
84: errx(1, "internal error: addrlen < res->ai_addrlen");
1.1 jakob 85: }
1.14 djm 86: memcpy(addr, res->ai_addr, res->ai_addrlen);
87: freeaddrinfo(res);
88: return (0);
1.1 jakob 89: }
90:
1.9 djm 91: static int
1.15 avsm 92: proxy_read_line(int fd, char *buf, size_t bufsz)
1.9 djm 93: {
1.15 avsm 94: size_t off;
1.9 djm 95:
96: for(off = 0;;) {
97: if (off >= bufsz)
98: errx(1, "proxy read too long");
1.15 avsm 99: if (atomicio(read, fd, buf + off, 1) != 1)
1.9 djm 100: err(1, "proxy read");
101: /* Skip CR */
102: if (buf[off] == '\r')
103: continue;
104: if (buf[off] == '\n') {
105: buf[off] = '\0';
106: break;
107: }
108: off++;
109: }
110: return (off);
111: }
112:
1.25 deraadt 113: static void
114: getproxypass(const char *proxyuser, const char *proxyhost,
115: char *pw, size_t pwlen)
1.16 djm 116: {
117: char prompt[512];
118:
119: snprintf(prompt, sizeof(prompt), "Proxy password for %s@%s: ",
120: proxyuser, proxyhost);
1.25 deraadt 121: if (readpassphrase(prompt, pw, pwlen, RPP_REQUIRE_TTY) == NULL)
1.16 djm 122: errx(1, "Unable to read proxy passphrase");
123: }
124:
1.22 mmcc 125: /*
126: * Error strings adapted from the generally accepted SOCKSv4 spec:
127: *
128: * http://ftp.icm.edu.pl/packages/socks/socks4/SOCKS4.protocol
129: */
130: static const char *
131: socks4_strerror(int e)
132: {
133: switch (e) {
134: case 90:
135: return "Succeeded";
136: case 91:
137: return "Request rejected or failed";
138: case 92:
139: return "SOCKS server cannot connect to identd on the client";
140: case 93:
141: return "Client program and identd report different user-ids";
142: default:
143: return "Unknown error";
144: }
145: }
146:
147: /*
148: * Error strings taken almost directly from RFC 1928.
149: */
150: static const char *
151: socks5_strerror(int e)
152: {
153: switch (e) {
154: case 0:
155: return "Succeeded";
156: case 1:
157: return "General SOCKS server failure";
158: case 2:
159: return "Connection not allowed by ruleset";
160: case 3:
161: return "Network unreachable";
162: case 4:
163: return "Host unreachable";
164: case 5:
165: return "Connection refused";
166: case 6:
167: return "TTL expired";
168: case 7:
169: return "Command not supported";
170: case 8:
171: return "Address type not supported";
172: default:
173: return "Unknown error";
174: }
175: }
176:
1.1 jakob 177: int
1.10 otto 178: socks_connect(const char *host, const char *port,
179: struct addrinfo hints __attribute__ ((__unused__)),
180: const char *proxyhost, const char *proxyport, struct addrinfo proxyhints,
1.16 djm 181: int socksv, const char *proxyuser)
1.1 jakob 182: {
1.16 djm 183: int proxyfd, r, authretry = 0;
1.14 djm 184: size_t hlen, wlen;
1.9 djm 185: unsigned char buf[1024];
1.15 avsm 186: size_t cnt;
1.14 djm 187: struct sockaddr_storage addr;
188: struct sockaddr_in *in4 = (struct sockaddr_in *)&addr;
189: struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)&addr;
1.1 jakob 190: in_port_t serverport;
191:
1.9 djm 192: if (proxyport == NULL)
193: proxyport = (socksv == -1) ? HTTP_PROXY_PORT : SOCKS_PORT;
194:
1.14 djm 195: /* Abuse API to lookup port */
196: if (decode_addrport("0.0.0.0", port, (struct sockaddr *)&addr,
197: sizeof(addr), 1, 1) == -1)
198: errx(1, "unknown port \"%.64s\"", port);
199: serverport = in4->sin_port;
1.1 jakob 200:
1.16 djm 201: again:
202: if (authretry++ > 3)
203: errx(1, "Too many authentication failures");
204:
205: proxyfd = remote_connect(proxyhost, proxyport, proxyhints);
206:
207: if (proxyfd < 0)
208: return (-1);
209:
1.5 markus 210: if (socksv == 5) {
1.14 djm 211: if (decode_addrport(host, port, (struct sockaddr *)&addr,
212: sizeof(addr), 0, 1) == -1)
213: addr.ss_family = 0; /* used in switch below */
214:
1.5 markus 215: /* Version 5, one method: no authentication */
216: buf[0] = SOCKS_V5;
217: buf[1] = 1;
218: buf[2] = SOCKS_NOAUTH;
1.15 avsm 219: cnt = atomicio(vwrite, proxyfd, buf, 3);
1.5 markus 220: if (cnt != 3)
1.18 nicm 221: err(1, "write failed (%zu/3)", cnt);
1.15 avsm 222:
223: cnt = atomicio(read, proxyfd, buf, 2);
224: if (cnt != 2)
1.18 nicm 225: err(1, "read failed (%zu/3)", cnt);
1.5 markus 226:
227: if (buf[1] == SOCKS_NOMETHOD)
1.11 djm 228: errx(1, "authentication method negotiation failed");
1.5 markus 229:
1.14 djm 230: switch (addr.ss_family) {
231: case 0:
232: /* Version 5, connect: domain name */
233:
234: /* Max domain name length is 255 bytes */
235: hlen = strlen(host);
236: if (hlen > 255)
237: errx(1, "host name too long for SOCKS5");
238: buf[0] = SOCKS_V5;
239: buf[1] = SOCKS_CONNECT;
240: buf[2] = 0;
241: buf[3] = SOCKS_DOMAIN;
242: buf[4] = hlen;
1.24 deraadt 243: memcpy(buf + 5, host, hlen);
1.14 djm 244: memcpy(buf + 5 + hlen, &serverport, sizeof serverport);
245: wlen = 7 + hlen;
246: break;
247: case AF_INET:
248: /* Version 5, connect: IPv4 address */
249: buf[0] = SOCKS_V5;
250: buf[1] = SOCKS_CONNECT;
251: buf[2] = 0;
252: buf[3] = SOCKS_IPV4;
253: memcpy(buf + 4, &in4->sin_addr, sizeof in4->sin_addr);
254: memcpy(buf + 8, &in4->sin_port, sizeof in4->sin_port);
255: wlen = 10;
256: break;
257: case AF_INET6:
258: /* Version 5, connect: IPv6 address */
259: buf[0] = SOCKS_V5;
260: buf[1] = SOCKS_CONNECT;
261: buf[2] = 0;
262: buf[3] = SOCKS_IPV6;
263: memcpy(buf + 4, &in6->sin6_addr, sizeof in6->sin6_addr);
264: memcpy(buf + 20, &in6->sin6_port,
265: sizeof in6->sin6_port);
266: wlen = 22;
267: break;
268: default:
269: errx(1, "internal error: silly AF");
270: }
1.5 markus 271:
1.15 avsm 272: cnt = atomicio(vwrite, proxyfd, buf, wlen);
1.14 djm 273: if (cnt != wlen)
1.18 nicm 274: err(1, "write failed (%zu/%zu)", cnt, wlen);
1.5 markus 275:
1.19 okan 276: cnt = atomicio(read, proxyfd, buf, 4);
277: if (cnt != 4)
278: err(1, "read failed (%zu/4)", cnt);
1.22 mmcc 279: if (buf[1] != 0) {
1.23 mmcc 280: errx(1, "connection failed, SOCKSv5 error: %s",
1.22 mmcc 281: socks5_strerror(buf[1]));
282: }
1.19 okan 283: switch (buf[3]) {
284: case SOCKS_IPV4:
285: cnt = atomicio(read, proxyfd, buf + 4, 6);
286: if (cnt != 6)
1.20 espie 287: err(1, "read failed (%zu/6)", cnt);
1.19 okan 288: break;
289: case SOCKS_IPV6:
290: cnt = atomicio(read, proxyfd, buf + 4, 18);
291: if (cnt != 18)
1.20 espie 292: err(1, "read failed (%zu/18)", cnt);
1.19 okan 293: break;
294: default:
295: errx(1, "connection failed, unsupported address type");
296: }
1.9 djm 297: } else if (socksv == 4) {
1.14 djm 298: /* This will exit on lookup failure */
299: decode_addrport(host, port, (struct sockaddr *)&addr,
300: sizeof(addr), 1, 0);
301:
1.5 markus 302: /* Version 4 */
303: buf[0] = SOCKS_V4;
304: buf[1] = SOCKS_CONNECT; /* connect */
1.14 djm 305: memcpy(buf + 2, &in4->sin_port, sizeof in4->sin_port);
306: memcpy(buf + 4, &in4->sin_addr, sizeof in4->sin_addr);
1.5 markus 307: buf[8] = 0; /* empty username */
1.14 djm 308: wlen = 9;
1.5 markus 309:
1.15 avsm 310: cnt = atomicio(vwrite, proxyfd, buf, wlen);
1.14 djm 311: if (cnt != wlen)
1.18 nicm 312: err(1, "write failed (%zu/%zu)", cnt, wlen);
1.5 markus 313:
1.14 djm 314: cnt = atomicio(read, proxyfd, buf, 8);
1.5 markus 315: if (cnt != 8)
1.18 nicm 316: err(1, "read failed (%zu/8)", cnt);
1.22 mmcc 317: if (buf[1] != 90) {
1.23 mmcc 318: errx(1, "connection failed, SOCKSv4 error: %s",
1.22 mmcc 319: socks4_strerror(buf[1]));
320: }
1.9 djm 321: } else if (socksv == -1) {
322: /* HTTP proxy CONNECT */
323:
324: /* Disallow bad chars in hostname */
325: if (strcspn(host, "\r\n\t []:") != strlen(host))
1.11 djm 326: errx(1, "Invalid hostname");
1.9 djm 327:
328: /* Try to be sane about numeric IPv6 addresses */
329: if (strchr(host, ':') != NULL) {
330: r = snprintf(buf, sizeof(buf),
1.16 djm 331: "CONNECT [%s]:%d HTTP/1.0\r\n",
1.9 djm 332: host, ntohs(serverport));
333: } else {
334: r = snprintf(buf, sizeof(buf),
1.16 djm 335: "CONNECT %s:%d HTTP/1.0\r\n",
1.9 djm 336: host, ntohs(serverport));
337: }
1.10 otto 338: if (r == -1 || (size_t)r >= sizeof(buf))
1.11 djm 339: errx(1, "hostname too long");
1.9 djm 340: r = strlen(buf);
341:
1.15 avsm 342: cnt = atomicio(vwrite, proxyfd, buf, r);
1.9 djm 343: if (cnt != r)
1.18 nicm 344: err(1, "write failed (%zu/%d)", cnt, r);
1.9 djm 345:
1.16 djm 346: if (authretry > 1) {
1.25 deraadt 347: char proxypass[256];
1.16 djm 348: char resp[1024];
349:
1.25 deraadt 350: getproxypass(proxyuser, proxyhost,
351: proxypass, sizeof proxypass);
1.16 djm 352: r = snprintf(buf, sizeof(buf), "%s:%s",
353: proxyuser, proxypass);
1.25 deraadt 354: explicit_bzero(proxypass, sizeof proxypass);
1.16 djm 355: if (r == -1 || (size_t)r >= sizeof(buf) ||
356: b64_ntop(buf, strlen(buf), resp,
357: sizeof(resp)) == -1)
358: errx(1, "Proxy username/password too long");
359: r = snprintf(buf, sizeof(buf), "Proxy-Authorization: "
360: "Basic %s\r\n", resp);
361: if (r == -1 || (size_t)r >= sizeof(buf))
362: errx(1, "Proxy auth response too long");
363: r = strlen(buf);
364: if ((cnt = atomicio(vwrite, proxyfd, buf, r)) != r)
1.18 nicm 365: err(1, "write failed (%zu/%d)", cnt, r);
1.25 deraadt 366: explicit_bzero(proxypass, sizeof proxypass);
367: explicit_bzero(buf, sizeof buf);
1.16 djm 368: }
369:
370: /* Terminate headers */
1.21 tobias 371: if ((cnt = atomicio(vwrite, proxyfd, "\r\n", 2)) != 2)
372: err(1, "write failed (%zu/2)", cnt);
1.16 djm 373:
374: /* Read status reply */
375: proxy_read_line(proxyfd, buf, sizeof(buf));
376: if (proxyuser != NULL &&
377: strncmp(buf, "HTTP/1.0 407 ", 12) == 0) {
378: if (authretry > 1) {
379: fprintf(stderr, "Proxy authentication "
380: "failed\n");
381: }
382: close(proxyfd);
383: goto again;
1.17 ray 384: } else if (strncmp(buf, "HTTP/1.0 200 ", 12) != 0 &&
385: strncmp(buf, "HTTP/1.1 200 ", 12) != 0)
1.16 djm 386: errx(1, "Proxy error: \"%s\"", buf);
387:
388: /* Headers continue until we hit an empty line */
1.9 djm 389: for (r = 0; r < HTTP_MAXHDRS; r++) {
390: proxy_read_line(proxyfd, buf, sizeof(buf));
391: if (*buf == '\0')
392: break;
393: }
1.16 djm 394: if (*buf != '\0')
395: errx(1, "Too many proxy headers received");
1.9 djm 396: } else
1.11 djm 397: errx(1, "Unknown proxy protocol %d", socksv);
1.1 jakob 398:
1.11 djm 399: return (proxyfd);
1.1 jakob 400: }
![[BACK]](/icons/back.gif){kind=icon}
Return to socks.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / nc