[gssapi-openssh.git] / openssh / auth-options.c

/*
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
 *                    All rights reserved
 * As far as I am concerned, the code I have written for this software
 * can be used freely for any purpose.  Any derived versions of this
 * software must be clearly marked as such, and if the derived work is
 * incompatible with the protocol description in the RFC file, it must be
 * called by a name other than "ssh" or "Secure Shell".
 */

#include "includes.h"
RCSID("$OpenBSD: auth-options.c,v 1.20 2001/08/30 20:36:34 stevesk Exp $");

#include "packet.h"
#include "xmalloc.h"
#include "match.h"
#include "log.h"
#include "canohost.h"
#include "channels.h"
#include "auth-options.h"
#include "servconf.h"
#include "misc.h"

/* Flags set authorized_keys flags */
int no_port_forwarding_flag = 0;
int no_agent_forwarding_flag = 0;
int no_x11_forwarding_flag = 0;
int no_pty_flag = 0;

/* "command=" option. */
char *forced_command = NULL;

/* "environment=" options. */
struct envstring *custom_environment = NULL;

extern ServerOptions options;

void
auth_clear_options(void)
{
	no_agent_forwarding_flag = 0;
	no_port_forwarding_flag = 0;
	no_pty_flag = 0;
	no_x11_forwarding_flag = 0;
	while (custom_environment) {
		struct envstring *ce = custom_environment;
		custom_environment = ce->next;
		xfree(ce->s);
		xfree(ce);
	}
	if (forced_command) {
		xfree(forced_command);
		forced_command = NULL;
	}
	channel_clear_permitted_opens();
}

/*
 * return 1 if access is granted, 0 if not.
 * side effect: sets key option flags
 */
int
auth_parse_options(struct passwd *pw, char *opts, char *file, u_long linenum)
{
	const char *cp;
	int i;

	/* reset options */
	auth_clear_options();

	if (!opts)
		return 1;

	while (*opts && *opts != ' ' && *opts != '\t') {
		cp = "no-port-forwarding";
		if (strncasecmp(opts, cp, strlen(cp)) == 0) {
			packet_send_debug("Port forwarding disabled.");
			no_port_forwarding_flag = 1;
			opts += strlen(cp);
			goto next_option;
		}
		cp = "no-agent-forwarding";
		if (strncasecmp(opts, cp, strlen(cp)) == 0) {
			packet_send_debug("Agent forwarding disabled.");
			no_agent_forwarding_flag = 1;
			opts += strlen(cp);
			goto next_option;
		}
		cp = "no-X11-forwarding";
		if (strncasecmp(opts, cp, strlen(cp)) == 0) {
			packet_send_debug("X11 forwarding disabled.");
			no_x11_forwarding_flag = 1;
			opts += strlen(cp);
			goto next_option;
		}
		cp = "no-pty";
		if (strncasecmp(opts, cp, strlen(cp)) == 0) {
			packet_send_debug("Pty allocation disabled.");
			no_pty_flag = 1;
			opts += strlen(cp);
			goto next_option;
		}
		cp = "command=\"";
		if (strncasecmp(opts, cp, strlen(cp)) == 0) {
			opts += strlen(cp);
			forced_command = xmalloc(strlen(opts) + 1);
			i = 0;
			while (*opts) {
				if (*opts == '"')
					break;
				if (*opts == '\\' && opts[1] == '"') {
					opts += 2;
					forced_command[i++] = '"';
					continue;
				}
				forced_command[i++] = *opts++;
			}
			if (!*opts) {
				debug("%.100s, line %lu: missing end quote",
				    file, linenum);
				packet_send_debug("%.100s, line %lu: missing end quote",
				    file, linenum);
				xfree(forced_command);
				forced_command = NULL;
				goto bad_option;
			}
			forced_command[i] = 0;
			packet_send_debug("Forced command: %.900s", forced_command);
			opts++;
			goto next_option;
		}
		cp = "environment=\"";
		if (strncasecmp(opts, cp, strlen(cp)) == 0) {
			char *s;
			struct envstring *new_envstring;

			opts += strlen(cp);
			s = xmalloc(strlen(opts) + 1);
			i = 0;
			while (*opts) {
				if (*opts == '"')
					break;
				if (*opts == '\\' && opts[1] == '"') {
					opts += 2;
					s[i++] = '"';
					continue;
				}
				s[i++] = *opts++;
			}
			if (!*opts) {
				debug("%.100s, line %lu: missing end quote",
				    file, linenum);
				packet_send_debug("%.100s, line %lu: missing end quote",
				    file, linenum);
				xfree(s);
				goto bad_option;
			}
			s[i] = 0;
			packet_send_debug("Adding to environment: %.900s", s);
			debug("Adding to environment: %.900s", s);
			opts++;
			new_envstring = xmalloc(sizeof(struct envstring));
			new_envstring->s = s;
			new_envstring->next = custom_environment;
			custom_environment = new_envstring;
			goto next_option;
		}
		cp = "from=\"";
		if (strncasecmp(opts, cp, strlen(cp)) == 0) {
			const char *remote_ip = get_remote_ipaddr();
			const char *remote_host = get_canonical_hostname(
			    options.reverse_mapping_check);
			char *patterns = xmalloc(strlen(opts) + 1);

			opts += strlen(cp);
			i = 0;
			while (*opts) {
				if (*opts == '"')
					break;
				if (*opts == '\\' && opts[1] == '"') {
					opts += 2;
					patterns[i++] = '"';
					continue;
				}
				patterns[i++] = *opts++;
			}
			if (!*opts) {
				debug("%.100s, line %lu: missing end quote",
				    file, linenum);
				packet_send_debug("%.100s, line %lu: missing end quote",
				    file, linenum);
				xfree(patterns);
				goto bad_option;
			}
			patterns[i] = 0;
			opts++;
			if (match_host_and_ip(remote_host, remote_ip,
			    patterns) != 1) {
				xfree(patterns);
				log("Authentication tried for %.100s with "
				    "correct key but not from a permitted "
				    "host (host=%.200s, ip=%.200s).",
				    pw->pw_name, remote_host, remote_ip);
				packet_send_debug("Your host '%.200s' is not "
				    "permitted to use this key for login.",
				    remote_host);
				/* deny access */
				return 0;
			}
			xfree(patterns);
			/* Host name matches. */
			goto next_option;
		}
		cp = "permitopen=\"";
		if (strncasecmp(opts, cp, strlen(cp)) == 0) {
			char host[256], sport[6];
			u_short port;
			char *patterns = xmalloc(strlen(opts) + 1);

			opts += strlen(cp);
			i = 0;
			while (*opts) {
				if (*opts == '"')
					break;
				if (*opts == '\\' && opts[1] == '"') {
					opts += 2;
					patterns[i++] = '"';
					continue;
				}
				patterns[i++] = *opts++;
			}
			if (!*opts) {
				debug("%.100s, line %lu: missing end quote",
				    file, linenum);
				packet_send_debug("%.100s, line %lu: missing end quote",
				    file, linenum);
				xfree(patterns);
				goto bad_option;
			}
			patterns[i] = 0;
			opts++;
			if (sscanf(patterns, "%255[^:]:%5[0-9]", host, sport) != 2 &&
			    sscanf(patterns, "%255[^/]/%5[0-9]", host, sport) != 2) {
				debug("%.100s, line %lu: Bad permitopen specification "
				    "<%.100s>", file, linenum, patterns);
				packet_send_debug("%.100s, line %lu: "
				    "Bad permitopen specification", file, linenum);
				xfree(patterns);
				goto bad_option;
			}
			if ((port = a2port(sport)) == 0) {
				debug("%.100s, line %lu: Bad permitopen port <%.100s>",
				    file, linenum, sport);
				packet_send_debug("%.100s, line %lu: "
				    "Bad permitopen port", file, linenum);
				xfree(patterns);
				goto bad_option;
			}
			if (options.allow_tcp_forwarding)
				channel_add_permitted_opens(host, port);
			xfree(patterns);
			goto next_option;
		}
next_option:
		/*
		 * Skip the comma, and move to the next option
		 * (or break out if there are no more).
		 */
		if (!*opts)
			fatal("Bugs in auth-options.c option processing.");
		if (*opts == ' ' || *opts == '\t')
			break;		/* End of options. */
		if (*opts != ',')
			goto bad_option;
		opts++;
		/* Process the next option. */
	}
	/* grant access */
	return 1;

bad_option:
	log("Bad options in %.100s file, line %lu: %.50s",
	    file, linenum, opts);
	packet_send_debug("Bad options in %.100s file, line %lu: %.50s",
	    file, linenum, opts);
	/* deny access */
	return 0;
}
Commit	Line	Data
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	}