Annotation of src/usr.bin/ssh/auth-options.c, Revision 1.38
1.38 ! dtucker 1: /* $OpenBSD: auth-options.c,v 1.37 2006/07/12 22:28:51 stevesk Exp $ */
1.3 deraadt 2: /*
3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * As far as I am concerned, the code I have written for this software
7: * can be used freely for any purpose. Any derived versions of this
8: * software must be clearly marked as such, and if the derived work is
9: * incompatible with the protocol description in the RFC file, it must be
10: * called by a name other than "ssh" or "Secure Shell".
11: */
12:
1.1 markus 13: #include "includes.h"
1.36 stevesk 14:
15: #include <sys/types.h>
16:
1.37 stevesk 17: #include <netdb.h>
1.36 stevesk 18: #include <pwd.h>
1.1 markus 19:
20: #include "xmalloc.h"
21: #include "match.h"
1.11 markus 22: #include "log.h"
23: #include "canohost.h"
1.18 markus 24: #include "channels.h"
1.11 markus 25: #include "auth-options.h"
1.12 markus 26: #include "servconf.h"
1.20 stevesk 27: #include "misc.h"
1.22 provos 28: #include "monitor_wrap.h"
1.24 markus 29: #include "auth.h"
1.1 markus 30:
31: /* Flags set authorized_keys flags */
32: int no_port_forwarding_flag = 0;
33: int no_agent_forwarding_flag = 0;
34: int no_x11_forwarding_flag = 0;
35: int no_pty_flag = 0;
36:
37: /* "command=" option. */
38: char *forced_command = NULL;
39:
40: /* "environment=" options. */
41: struct envstring *custom_environment = NULL;
42:
1.32 reyk 43: /* "tunnel=" option. */
44: int forced_tun_device = -1;
45:
1.12 markus 46: extern ServerOptions options;
47:
1.22 provos 48: void
1.5 markus 49: auth_clear_options(void)
50: {
51: no_agent_forwarding_flag = 0;
52: no_port_forwarding_flag = 0;
53: no_pty_flag = 0;
54: no_x11_forwarding_flag = 0;
55: while (custom_environment) {
56: struct envstring *ce = custom_environment;
57: custom_environment = ce->next;
58: xfree(ce->s);
59: xfree(ce);
60: }
61: if (forced_command) {
62: xfree(forced_command);
63: forced_command = NULL;
64: }
1.32 reyk 65: forced_tun_device = -1;
1.15 markus 66: channel_clear_permitted_opens();
1.24 markus 67: auth_debug_reset();
1.5 markus 68: }
69:
1.10 markus 70: /*
71: * return 1 if access is granted, 0 if not.
72: * side effect: sets key option flags
73: */
1.1 markus 74: int
1.12 markus 75: auth_parse_options(struct passwd *pw, char *opts, char *file, u_long linenum)
1.1 markus 76: {
77: const char *cp;
1.15 markus 78: int i;
1.5 markus 79:
80: /* reset options */
81: auth_clear_options();
1.13 markus 82:
83: if (!opts)
84: return 1;
1.5 markus 85:
1.12 markus 86: while (*opts && *opts != ' ' && *opts != '\t') {
1.1 markus 87: cp = "no-port-forwarding";
1.12 markus 88: if (strncasecmp(opts, cp, strlen(cp)) == 0) {
1.24 markus 89: auth_debug_add("Port forwarding disabled.");
1.1 markus 90: no_port_forwarding_flag = 1;
1.12 markus 91: opts += strlen(cp);
1.1 markus 92: goto next_option;
93: }
94: cp = "no-agent-forwarding";
1.12 markus 95: if (strncasecmp(opts, cp, strlen(cp)) == 0) {
1.24 markus 96: auth_debug_add("Agent forwarding disabled.");
1.1 markus 97: no_agent_forwarding_flag = 1;
1.12 markus 98: opts += strlen(cp);
1.1 markus 99: goto next_option;
100: }
101: cp = "no-X11-forwarding";
1.12 markus 102: if (strncasecmp(opts, cp, strlen(cp)) == 0) {
1.24 markus 103: auth_debug_add("X11 forwarding disabled.");
1.1 markus 104: no_x11_forwarding_flag = 1;
1.12 markus 105: opts += strlen(cp);
1.1 markus 106: goto next_option;
107: }
108: cp = "no-pty";
1.12 markus 109: if (strncasecmp(opts, cp, strlen(cp)) == 0) {
1.24 markus 110: auth_debug_add("Pty allocation disabled.");
1.1 markus 111: no_pty_flag = 1;
1.12 markus 112: opts += strlen(cp);
1.1 markus 113: goto next_option;
114: }
115: cp = "command=\"";
1.12 markus 116: if (strncasecmp(opts, cp, strlen(cp)) == 0) {
117: opts += strlen(cp);
118: forced_command = xmalloc(strlen(opts) + 1);
1.1 markus 119: i = 0;
1.12 markus 120: while (*opts) {
121: if (*opts == '"')
1.1 markus 122: break;
1.12 markus 123: if (*opts == '\\' && opts[1] == '"') {
124: opts += 2;
1.1 markus 125: forced_command[i++] = '"';
126: continue;
127: }
1.12 markus 128: forced_command[i++] = *opts++;
1.1 markus 129: }
1.12 markus 130: if (!*opts) {
1.1 markus 131: debug("%.100s, line %lu: missing end quote",
1.10 markus 132: file, linenum);
1.24 markus 133: auth_debug_add("%.100s, line %lu: missing end quote",
1.10 markus 134: file, linenum);
1.14 markus 135: xfree(forced_command);
136: forced_command = NULL;
137: goto bad_option;
1.1 markus 138: }
1.38 ! dtucker 139: forced_command[i] = '\0';
1.24 markus 140: auth_debug_add("Forced command: %.900s", forced_command);
1.12 markus 141: opts++;
1.1 markus 142: goto next_option;
143: }
144: cp = "environment=\"";
1.26 markus 145: if (options.permit_user_env &&
146: strncasecmp(opts, cp, strlen(cp)) == 0) {
1.1 markus 147: char *s;
148: struct envstring *new_envstring;
1.15 markus 149:
1.12 markus 150: opts += strlen(cp);
151: s = xmalloc(strlen(opts) + 1);
1.1 markus 152: i = 0;
1.12 markus 153: while (*opts) {
154: if (*opts == '"')
1.1 markus 155: break;
1.12 markus 156: if (*opts == '\\' && opts[1] == '"') {
157: opts += 2;
1.1 markus 158: s[i++] = '"';
159: continue;
160: }
1.12 markus 161: s[i++] = *opts++;
1.1 markus 162: }
1.12 markus 163: if (!*opts) {
1.1 markus 164: debug("%.100s, line %lu: missing end quote",
1.10 markus 165: file, linenum);
1.24 markus 166: auth_debug_add("%.100s, line %lu: missing end quote",
1.10 markus 167: file, linenum);
1.14 markus 168: xfree(s);
169: goto bad_option;
1.1 markus 170: }
1.38 ! dtucker 171: s[i] = '\0';
1.24 markus 172: auth_debug_add("Adding to environment: %.900s", s);
1.1 markus 173: debug("Adding to environment: %.900s", s);
1.12 markus 174: opts++;
1.1 markus 175: new_envstring = xmalloc(sizeof(struct envstring));
176: new_envstring->s = s;
177: new_envstring->next = custom_environment;
178: custom_environment = new_envstring;
179: goto next_option;
180: }
181: cp = "from=\"";
1.12 markus 182: if (strncasecmp(opts, cp, strlen(cp)) == 0) {
183: const char *remote_ip = get_remote_ipaddr();
184: const char *remote_host = get_canonical_hostname(
1.28 markus 185: options.use_dns);
1.12 markus 186: char *patterns = xmalloc(strlen(opts) + 1);
1.15 markus 187:
1.12 markus 188: opts += strlen(cp);
1.1 markus 189: i = 0;
1.12 markus 190: while (*opts) {
191: if (*opts == '"')
1.1 markus 192: break;
1.12 markus 193: if (*opts == '\\' && opts[1] == '"') {
194: opts += 2;
1.1 markus 195: patterns[i++] = '"';
196: continue;
197: }
1.12 markus 198: patterns[i++] = *opts++;
1.1 markus 199: }
1.12 markus 200: if (!*opts) {
1.1 markus 201: debug("%.100s, line %lu: missing end quote",
1.10 markus 202: file, linenum);
1.24 markus 203: auth_debug_add("%.100s, line %lu: missing end quote",
1.10 markus 204: file, linenum);
1.14 markus 205: xfree(patterns);
206: goto bad_option;
1.1 markus 207: }
1.38 ! dtucker 208: patterns[i] = '\0';
1.12 markus 209: opts++;
1.19 markus 210: if (match_host_and_ip(remote_host, remote_ip,
211: patterns) != 1) {
212: xfree(patterns);
1.27 itojun 213: logit("Authentication tried for %.100s with "
1.12 markus 214: "correct key but not from a permitted "
215: "host (host=%.200s, ip=%.200s).",
216: pw->pw_name, remote_host, remote_ip);
1.24 markus 217: auth_debug_add("Your host '%.200s' is not "
1.12 markus 218: "permitted to use this key for login.",
219: remote_host);
1.1 markus 220: /* deny access */
221: return 0;
222: }
1.19 markus 223: xfree(patterns);
1.1 markus 224: /* Host name matches. */
1.15 markus 225: goto next_option;
226: }
227: cp = "permitopen=\"";
228: if (strncasecmp(opts, cp, strlen(cp)) == 0) {
1.29 djm 229: char *host, *p;
1.15 markus 230: u_short port;
231: char *patterns = xmalloc(strlen(opts) + 1);
232:
233: opts += strlen(cp);
234: i = 0;
235: while (*opts) {
236: if (*opts == '"')
237: break;
238: if (*opts == '\\' && opts[1] == '"') {
239: opts += 2;
240: patterns[i++] = '"';
241: continue;
242: }
243: patterns[i++] = *opts++;
244: }
245: if (!*opts) {
246: debug("%.100s, line %lu: missing end quote",
247: file, linenum);
1.29 djm 248: auth_debug_add("%.100s, line %lu: missing "
249: "end quote", file, linenum);
1.15 markus 250: xfree(patterns);
251: goto bad_option;
252: }
1.38 ! dtucker 253: patterns[i] = '\0';
1.15 markus 254: opts++;
1.29 djm 255: p = patterns;
256: host = hpdelim(&p);
257: if (host == NULL || strlen(host) >= NI_MAXHOST) {
258: debug("%.100s, line %lu: Bad permitopen "
1.31 deraadt 259: "specification <%.100s>", file, linenum,
1.29 djm 260: patterns);
1.24 markus 261: auth_debug_add("%.100s, line %lu: "
1.29 djm 262: "Bad permitopen specification", file,
263: linenum);
1.15 markus 264: xfree(patterns);
265: goto bad_option;
266: }
1.30 deraadt 267: host = cleanhostname(host);
268: if (p == NULL || (port = a2port(p)) == 0) {
1.29 djm 269: debug("%.100s, line %lu: Bad permitopen port "
270: "<%.100s>", file, linenum, p ? p : "");
1.24 markus 271: auth_debug_add("%.100s, line %lu: "
1.20 stevesk 272: "Bad permitopen port", file, linenum);
1.15 markus 273: xfree(patterns);
274: goto bad_option;
275: }
1.16 markus 276: if (options.allow_tcp_forwarding)
1.20 stevesk 277: channel_add_permitted_opens(host, port);
1.15 markus 278: xfree(patterns);
1.32 reyk 279: goto next_option;
280: }
281: cp = "tunnel=\"";
282: if (strncasecmp(opts, cp, strlen(cp)) == 0) {
283: char *tun = NULL;
284: opts += strlen(cp);
285: tun = xmalloc(strlen(opts) + 1);
286: i = 0;
287: while (*opts) {
288: if (*opts == '"')
289: break;
290: tun[i++] = *opts++;
291: }
292: if (!*opts) {
293: debug("%.100s, line %lu: missing end quote",
294: file, linenum);
295: auth_debug_add("%.100s, line %lu: missing end quote",
296: file, linenum);
297: xfree(tun);
298: forced_tun_device = -1;
299: goto bad_option;
300: }
1.38 ! dtucker 301: tun[i] = '\0';
1.32 reyk 302: forced_tun_device = a2tun(tun, NULL);
303: xfree(tun);
1.33 reyk 304: if (forced_tun_device == SSH_TUNID_ERR) {
1.32 reyk 305: debug("%.100s, line %lu: invalid tun device",
306: file, linenum);
307: auth_debug_add("%.100s, line %lu: invalid tun device",
308: file, linenum);
309: forced_tun_device = -1;
310: goto bad_option;
311: }
312: auth_debug_add("Forced tun device: %d", forced_tun_device);
313: opts++;
1.1 markus 314: goto next_option;
315: }
316: next_option:
317: /*
318: * Skip the comma, and move to the next option
319: * (or break out if there are no more).
320: */
1.12 markus 321: if (!*opts)
1.1 markus 322: fatal("Bugs in auth-options.c option processing.");
1.12 markus 323: if (*opts == ' ' || *opts == '\t')
1.1 markus 324: break; /* End of options. */
1.12 markus 325: if (*opts != ',')
1.1 markus 326: goto bad_option;
1.12 markus 327: opts++;
1.1 markus 328: /* Process the next option. */
329: }
1.22 provos 330:
331: if (!use_privsep)
1.24 markus 332: auth_debug_send();
1.22 provos 333:
1.1 markus 334: /* grant access */
335: return 1;
336:
337: bad_option:
1.27 itojun 338: logit("Bad options in %.100s file, line %lu: %.50s",
1.12 markus 339: file, linenum, opts);
1.24 markus 340: auth_debug_add("Bad options in %.100s file, line %lu: %.50s",
1.12 markus 341: file, linenum, opts);
1.22 provos 342:
343: if (!use_privsep)
1.24 markus 344: auth_debug_send();
1.22 provos 345:
1.1 markus 346: /* deny access */
347: return 0;
348: }