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3c0ef626 | 1 | /* |
2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> | |
3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
4 | * All rights reserved | |
5 | * As far as I am concerned, the code I have written for this software | |
6 | * can be used freely for any purpose. Any derived versions of this | |
7 | * software must be clearly marked as such, and if the derived work is | |
8 | * incompatible with the protocol description in the RFC file, it must be | |
9 | * called by a name other than "ssh" or "Secure Shell". | |
10 | */ | |
11 | ||
12 | #include "includes.h" | |
13 | RCSID("$OpenBSD: auth-options.c,v 1.20 2001/08/30 20:36:34 stevesk Exp $"); | |
14 | ||
15 | #include "packet.h" | |
16 | #include "xmalloc.h" | |
17 | #include "match.h" | |
18 | #include "log.h" | |
19 | #include "canohost.h" | |
20 | #include "channels.h" | |
21 | #include "auth-options.h" | |
22 | #include "servconf.h" | |
23 | #include "misc.h" | |
24 | ||
25 | /* Flags set authorized_keys flags */ | |
26 | int no_port_forwarding_flag = 0; | |
27 | int no_agent_forwarding_flag = 0; | |
28 | int no_x11_forwarding_flag = 0; | |
29 | int no_pty_flag = 0; | |
30 | ||
31 | /* "command=" option. */ | |
32 | char *forced_command = NULL; | |
33 | ||
34 | /* "environment=" options. */ | |
35 | struct envstring *custom_environment = NULL; | |
36 | ||
37 | extern ServerOptions options; | |
38 | ||
39 | void | |
40 | auth_clear_options(void) | |
41 | { | |
42 | no_agent_forwarding_flag = 0; | |
43 | no_port_forwarding_flag = 0; | |
44 | no_pty_flag = 0; | |
45 | no_x11_forwarding_flag = 0; | |
46 | while (custom_environment) { | |
47 | struct envstring *ce = custom_environment; | |
48 | custom_environment = ce->next; | |
49 | xfree(ce->s); | |
50 | xfree(ce); | |
51 | } | |
52 | if (forced_command) { | |
53 | xfree(forced_command); | |
54 | forced_command = NULL; | |
55 | } | |
56 | channel_clear_permitted_opens(); | |
57 | } | |
58 | ||
59 | /* | |
60 | * return 1 if access is granted, 0 if not. | |
61 | * side effect: sets key option flags | |
62 | */ | |
63 | int | |
64 | auth_parse_options(struct passwd *pw, char *opts, char *file, u_long linenum) | |
65 | { | |
66 | const char *cp; | |
67 | int i; | |
68 | ||
69 | /* reset options */ | |
70 | auth_clear_options(); | |
71 | ||
72 | if (!opts) | |
73 | return 1; | |
74 | ||
75 | while (*opts && *opts != ' ' && *opts != '\t') { | |
76 | cp = "no-port-forwarding"; | |
77 | if (strncasecmp(opts, cp, strlen(cp)) == 0) { | |
78 | packet_send_debug("Port forwarding disabled."); | |
79 | no_port_forwarding_flag = 1; | |
80 | opts += strlen(cp); | |
81 | goto next_option; | |
82 | } | |
83 | cp = "no-agent-forwarding"; | |
84 | if (strncasecmp(opts, cp, strlen(cp)) == 0) { | |
85 | packet_send_debug("Agent forwarding disabled."); | |
86 | no_agent_forwarding_flag = 1; | |
87 | opts += strlen(cp); | |
88 | goto next_option; | |
89 | } | |
90 | cp = "no-X11-forwarding"; | |
91 | if (strncasecmp(opts, cp, strlen(cp)) == 0) { | |
92 | packet_send_debug("X11 forwarding disabled."); | |
93 | no_x11_forwarding_flag = 1; | |
94 | opts += strlen(cp); | |
95 | goto next_option; | |
96 | } | |
97 | cp = "no-pty"; | |
98 | if (strncasecmp(opts, cp, strlen(cp)) == 0) { | |
99 | packet_send_debug("Pty allocation disabled."); | |
100 | no_pty_flag = 1; | |
101 | opts += strlen(cp); | |
102 | goto next_option; | |
103 | } | |
104 | cp = "command=\""; | |
105 | if (strncasecmp(opts, cp, strlen(cp)) == 0) { | |
106 | opts += strlen(cp); | |
107 | forced_command = xmalloc(strlen(opts) + 1); | |
108 | i = 0; | |
109 | while (*opts) { | |
110 | if (*opts == '"') | |
111 | break; | |
112 | if (*opts == '\\' && opts[1] == '"') { | |
113 | opts += 2; | |
114 | forced_command[i++] = '"'; | |
115 | continue; | |
116 | } | |
117 | forced_command[i++] = *opts++; | |
118 | } | |
119 | if (!*opts) { | |
120 | debug("%.100s, line %lu: missing end quote", | |
121 | file, linenum); | |
122 | packet_send_debug("%.100s, line %lu: missing end quote", | |
123 | file, linenum); | |
124 | xfree(forced_command); | |
125 | forced_command = NULL; | |
126 | goto bad_option; | |
127 | } | |
128 | forced_command[i] = 0; | |
129 | packet_send_debug("Forced command: %.900s", forced_command); | |
130 | opts++; | |
131 | goto next_option; | |
132 | } | |
133 | cp = "environment=\""; | |
134 | if (strncasecmp(opts, cp, strlen(cp)) == 0) { | |
135 | char *s; | |
136 | struct envstring *new_envstring; | |
137 | ||
138 | opts += strlen(cp); | |
139 | s = xmalloc(strlen(opts) + 1); | |
140 | i = 0; | |
141 | while (*opts) { | |
142 | if (*opts == '"') | |
143 | break; | |
144 | if (*opts == '\\' && opts[1] == '"') { | |
145 | opts += 2; | |
146 | s[i++] = '"'; | |
147 | continue; | |
148 | } | |
149 | s[i++] = *opts++; | |
150 | } | |
151 | if (!*opts) { | |
152 | debug("%.100s, line %lu: missing end quote", | |
153 | file, linenum); | |
154 | packet_send_debug("%.100s, line %lu: missing end quote", | |
155 | file, linenum); | |
156 | xfree(s); | |
157 | goto bad_option; | |
158 | } | |
159 | s[i] = 0; | |
160 | packet_send_debug("Adding to environment: %.900s", s); | |
161 | debug("Adding to environment: %.900s", s); | |
162 | opts++; | |
163 | new_envstring = xmalloc(sizeof(struct envstring)); | |
164 | new_envstring->s = s; | |
165 | new_envstring->next = custom_environment; | |
166 | custom_environment = new_envstring; | |
167 | goto next_option; | |
168 | } | |
169 | cp = "from=\""; | |
170 | if (strncasecmp(opts, cp, strlen(cp)) == 0) { | |
171 | const char *remote_ip = get_remote_ipaddr(); | |
172 | const char *remote_host = get_canonical_hostname( | |
173 | options.reverse_mapping_check); | |
174 | char *patterns = xmalloc(strlen(opts) + 1); | |
175 | ||
176 | opts += strlen(cp); | |
177 | i = 0; | |
178 | while (*opts) { | |
179 | if (*opts == '"') | |
180 | break; | |
181 | if (*opts == '\\' && opts[1] == '"') { | |
182 | opts += 2; | |
183 | patterns[i++] = '"'; | |
184 | continue; | |
185 | } | |
186 | patterns[i++] = *opts++; | |
187 | } | |
188 | if (!*opts) { | |
189 | debug("%.100s, line %lu: missing end quote", | |
190 | file, linenum); | |
191 | packet_send_debug("%.100s, line %lu: missing end quote", | |
192 | file, linenum); | |
193 | xfree(patterns); | |
194 | goto bad_option; | |
195 | } | |
196 | patterns[i] = 0; | |
197 | opts++; | |
198 | if (match_host_and_ip(remote_host, remote_ip, | |
199 | patterns) != 1) { | |
200 | xfree(patterns); | |
201 | log("Authentication tried for %.100s with " | |
202 | "correct key but not from a permitted " | |
203 | "host (host=%.200s, ip=%.200s).", | |
204 | pw->pw_name, remote_host, remote_ip); | |
205 | packet_send_debug("Your host '%.200s' is not " | |
206 | "permitted to use this key for login.", | |
207 | remote_host); | |
208 | /* deny access */ | |
209 | return 0; | |
210 | } | |
211 | xfree(patterns); | |
212 | /* Host name matches. */ | |
213 | goto next_option; | |
214 | } | |
215 | cp = "permitopen=\""; | |
216 | if (strncasecmp(opts, cp, strlen(cp)) == 0) { | |
217 | char host[256], sport[6]; | |
218 | u_short port; | |
219 | char *patterns = xmalloc(strlen(opts) + 1); | |
220 | ||
221 | opts += strlen(cp); | |
222 | i = 0; | |
223 | while (*opts) { | |
224 | if (*opts == '"') | |
225 | break; | |
226 | if (*opts == '\\' && opts[1] == '"') { | |
227 | opts += 2; | |
228 | patterns[i++] = '"'; | |
229 | continue; | |
230 | } | |
231 | patterns[i++] = *opts++; | |
232 | } | |
233 | if (!*opts) { | |
234 | debug("%.100s, line %lu: missing end quote", | |
235 | file, linenum); | |
236 | packet_send_debug("%.100s, line %lu: missing end quote", | |
237 | file, linenum); | |
238 | xfree(patterns); | |
239 | goto bad_option; | |
240 | } | |
241 | patterns[i] = 0; | |
242 | opts++; | |
243 | if (sscanf(patterns, "%255[^:]:%5[0-9]", host, sport) != 2 && | |
244 | sscanf(patterns, "%255[^/]/%5[0-9]", host, sport) != 2) { | |
245 | debug("%.100s, line %lu: Bad permitopen specification " | |
246 | "<%.100s>", file, linenum, patterns); | |
247 | packet_send_debug("%.100s, line %lu: " | |
248 | "Bad permitopen specification", file, linenum); | |
249 | xfree(patterns); | |
250 | goto bad_option; | |
251 | } | |
252 | if ((port = a2port(sport)) == 0) { | |
253 | debug("%.100s, line %lu: Bad permitopen port <%.100s>", | |
254 | file, linenum, sport); | |
255 | packet_send_debug("%.100s, line %lu: " | |
256 | "Bad permitopen port", file, linenum); | |
257 | xfree(patterns); | |
258 | goto bad_option; | |
259 | } | |
260 | if (options.allow_tcp_forwarding) | |
261 | channel_add_permitted_opens(host, port); | |
262 | xfree(patterns); | |
263 | goto next_option; | |
264 | } | |
265 | next_option: | |
266 | /* | |
267 | * Skip the comma, and move to the next option | |
268 | * (or break out if there are no more). | |
269 | */ | |
270 | if (!*opts) | |
271 | fatal("Bugs in auth-options.c option processing."); | |
272 | if (*opts == ' ' || *opts == '\t') | |
273 | break; /* End of options. */ | |
274 | if (*opts != ',') | |
275 | goto bad_option; | |
276 | opts++; | |
277 | /* Process the next option. */ | |
278 | } | |
279 | /* grant access */ | |
280 | return 1; | |
281 | ||
282 | bad_option: | |
283 | log("Bad options in %.100s file, line %lu: %.50s", | |
284 | file, linenum, opts); | |
285 | packet_send_debug("Bad options in %.100s file, line %lu: %.50s", | |
286 | file, linenum, opts); | |
287 | /* deny access */ | |
288 | return 0; | |
289 | } |