[openssh.git] / auth-options.c

/* $OpenBSD: auth-options.c,v 1.37 2006/07/12 22:28:51 stevesk Exp $ */
/*
 * 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"

#include <sys/types.h>

#if defined(HAVE_NETDB_H)
# include <netdb.h>
#endif
#include <pwd.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"
#include "monitor_wrap.h"
#include "auth.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;

/* "tunnel=" option. */
int forced_tun_device = -1;

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;
	}
	forced_tun_device = -1;
	channel_clear_permitted_opens();
	auth_debug_reset();
}

/*
 * 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) {
			auth_debug_add("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) {
			auth_debug_add("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) {
			auth_debug_add("X11 forwarding disabled.");
			no_x11_forwarding_flag = 1;
			opts += strlen(cp);
			goto next_option;
		}
		cp = "no-pty";
		if (strncasecmp(opts, cp, strlen(cp)) == 0) {
			auth_debug_add("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);
				auth_debug_add("%.100s, line %lu: missing end quote",
				    file, linenum);
				xfree(forced_command);
				forced_command = NULL;
				goto bad_option;
			}
			forced_command[i] = 0;
			auth_debug_add("Forced command: %.900s", forced_command);
			opts++;
			goto next_option;
		}
		cp = "environment=\"";
		if (options.permit_user_env &&
		    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);
				auth_debug_add("%.100s, line %lu: missing end quote",
				    file, linenum);
				xfree(s);
				goto bad_option;
			}
			s[i] = 0;
			auth_debug_add("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.use_dns);
			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);
				auth_debug_add("%.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);
				logit("Authentication tried for %.100s with "
				    "correct key but not from a permitted "
				    "host (host=%.200s, ip=%.200s).",
				    pw->pw_name, remote_host, remote_ip);
				auth_debug_add("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, *p;
			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);
				auth_debug_add("%.100s, line %lu: missing "
				    "end quote", file, linenum);
				xfree(patterns);
				goto bad_option;
			}
			patterns[i] = 0;
			opts++;
			p = patterns;
			host = hpdelim(&p);
			if (host == NULL || strlen(host) >= NI_MAXHOST) {
				debug("%.100s, line %lu: Bad permitopen "
				    "specification <%.100s>", file, linenum,
				    patterns);
				auth_debug_add("%.100s, line %lu: "
				    "Bad permitopen specification", file,
				    linenum);
				xfree(patterns);
				goto bad_option;
			}
			host = cleanhostname(host);
			if (p == NULL || (port = a2port(p)) == 0) {
				debug("%.100s, line %lu: Bad permitopen port "
				    "<%.100s>", file, linenum, p ? p : "");
				auth_debug_add("%.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;
		}
		cp = "tunnel=\"";
		if (strncasecmp(opts, cp, strlen(cp)) == 0) {
			char *tun = NULL;
			opts += strlen(cp);
			tun = xmalloc(strlen(opts) + 1);
			i = 0;
			while (*opts) {
				if (*opts == '"')
					break;
				tun[i++] = *opts++;
			}
			if (!*opts) {
				debug("%.100s, line %lu: missing end quote",
				    file, linenum);
				auth_debug_add("%.100s, line %lu: missing end quote",
				    file, linenum);
				xfree(tun);
				forced_tun_device = -1;
				goto bad_option;
			}
			tun[i] = 0;
			forced_tun_device = a2tun(tun, NULL);
			xfree(tun);
			if (forced_tun_device == SSH_TUNID_ERR) {
				debug("%.100s, line %lu: invalid tun device",
				    file, linenum);
				auth_debug_add("%.100s, line %lu: invalid tun device",
				    file, linenum);
				forced_tun_device = -1;
				goto bad_option;
			}
			auth_debug_add("Forced tun device: %d", forced_tun_device);
			opts++;
			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. */
	}

	if (!use_privsep)
		auth_debug_send();

	/* grant access */
	return 1;

bad_option:
	logit("Bad options in %.100s file, line %lu: %.50s",
	    file, linenum, opts);
	auth_debug_add("Bad options in %.100s file, line %lu: %.50s",
	    file, linenum, opts);

	if (!use_privsep)
		auth_debug_send();

	/* deny access */
	return 0;
}
Commit	Line	Data
c8dfff33	1	/* $OpenBSD: auth-options.c,v 1.37 2006/07/12 22:28:51 stevesk Exp $ */
bcbf86ec	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
bcbf86ec	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
38c295d6	13	#include "includes.h"
38c295d6	14
b1842393	15	#include <sys/types.h>
b1842393	16
c8dfff33	17	#if defined(HAVE_NETDB_H)
	18	# include <netdb.h>
	19	#endif
b1842393	20	#include <pwd.h>
b1842393	21
38c295d6	22	#include "xmalloc.h"
38c295d6	23	#include "match.h"
42f11eb2	24	#include "log.h"
42f11eb2	25	#include "canohost.h"
a5efa1bb	26	#include "channels.h"
42f11eb2	27	#include "auth-options.h"
61e96248	28	#include "servconf.h"
ed787d14	29	#include "misc.h"
1853d1ef	30	#include "monitor_wrap.h"
01dafcb5	31	#include "auth.h"
38c295d6	32
	33	/* Flags set authorized_keys flags */
	34	int no_port_forwarding_flag = 0;
	35	int no_agent_forwarding_flag = 0;
	36	int no_x11_forwarding_flag = 0;
	37	int no_pty_flag = 0;
	38
	39	/* "command=" option. */
	40	char *forced_command = NULL;
	41
	42	/* "environment=" options. */
	43	struct envstring *custom_environment = NULL;
	44
d20f3c9e	45	/* "tunnel=" option. */
	46	int forced_tun_device = -1;
	47
61e96248	48	extern ServerOptions options;
61e96248	49
94ec8c6b	50	void
	51	auth_clear_options(void)
	52	{
	53	no_agent_forwarding_flag = 0;
	54	no_port_forwarding_flag = 0;
	55	no_pty_flag = 0;
	56	no_x11_forwarding_flag = 0;
	57	while (custom_environment) {
	58	struct envstring *ce = custom_environment;
	59	custom_environment = ce->next;
	60	xfree(ce->s);
	61	xfree(ce);
	62	}
	63	if (forced_command) {
	64	xfree(forced_command);
	65	forced_command = NULL;
	66	}
d20f3c9e	67	forced_tun_device = -1;
01794848	68	channel_clear_permitted_opens();
01dafcb5	69	auth_debug_reset();
94ec8c6b	70	}
94ec8c6b	71
42f11eb2	72	/*
	73	* return 1 if access is granted, 0 if not.
	74	* side effect: sets key option flags
	75	*/
38c295d6	76	int
61e96248	77	auth_parse_options(struct passwd pw, char opts, char *file, u_long linenum)
38c295d6	78	{
38c295d6	79	const char *cp;
01794848	80	int i;
94ec8c6b	81
	82	/* reset options */
	83	auth_clear_options();
	84
e0b2cf6b	85	if (!opts)
	86	return 1;
	87
61e96248	88	while (opts && opts != ' ' && *opts != '\t') {
38c295d6	89	cp = "no-port-forwarding";
61e96248	90	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
01dafcb5	91	auth_debug_add("Port forwarding disabled.");
38c295d6	92	no_port_forwarding_flag = 1;
61e96248	93	opts += strlen(cp);
38c295d6	94	goto next_option;
	95	}
	96	cp = "no-agent-forwarding";
61e96248	97	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
01dafcb5	98	auth_debug_add("Agent forwarding disabled.");
38c295d6	99	no_agent_forwarding_flag = 1;
61e96248	100	opts += strlen(cp);
38c295d6	101	goto next_option;
	102	}
	103	cp = "no-X11-forwarding";
61e96248	104	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
01dafcb5	105	auth_debug_add("X11 forwarding disabled.");
38c295d6	106	no_x11_forwarding_flag = 1;
61e96248	107	opts += strlen(cp);
38c295d6	108	goto next_option;
	109	}
	110	cp = "no-pty";
61e96248	111	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
01dafcb5	112	auth_debug_add("Pty allocation disabled.");
38c295d6	113	no_pty_flag = 1;
61e96248	114	opts += strlen(cp);
38c295d6	115	goto next_option;
	116	}
	117	cp = "command=\"";
61e96248	118	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
61e96248	119	opts += strlen(cp);
61e96248	120	forced_command = xmalloc(strlen(opts) + 1);
38c295d6	121	i = 0;
61e96248	122	while (*opts) {
61e96248	123	if (*opts == '"')
38c295d6	124	break;
61e96248	125	if (*opts == '\\' && opts[1] == '"') {
61e96248	126	opts += 2;
38c295d6	127	forced_command[i++] = '"';
	128	continue;
	129	}
61e96248	130	forced_command[i++] = *opts++;
38c295d6	131	}
61e96248	132	if (!*opts) {
38c295d6	133	debug("%.100s, line %lu: missing end quote",
42f11eb2	134	file, linenum);
01dafcb5	135	auth_debug_add("%.100s, line %lu: missing end quote",
42f11eb2	136	file, linenum);
acc9d6d7	137	xfree(forced_command);
	138	forced_command = NULL;
	139	goto bad_option;
38c295d6	140	}
38c295d6	141	forced_command[i] = 0;
01dafcb5	142	auth_debug_add("Forced command: %.900s", forced_command);
61e96248	143	opts++;
38c295d6	144	goto next_option;
	145	}
	146	cp = "environment=\"";
f00bab84	147	if (options.permit_user_env &&
f00bab84	148	strncasecmp(opts, cp, strlen(cp)) == 0) {
38c295d6	149	char *s;
38c295d6	150	struct envstring *new_envstring;
01794848	151
61e96248	152	opts += strlen(cp);
61e96248	153	s = xmalloc(strlen(opts) + 1);
38c295d6	154	i = 0;
61e96248	155	while (*opts) {
61e96248	156	if (*opts == '"')
38c295d6	157	break;
61e96248	158	if (*opts == '\\' && opts[1] == '"') {
61e96248	159	opts += 2;
38c295d6	160	s[i++] = '"';
	161	continue;
	162	}
61e96248	163	s[i++] = *opts++;
38c295d6	164	}
61e96248	165	if (!*opts) {
38c295d6	166	debug("%.100s, line %lu: missing end quote",
42f11eb2	167	file, linenum);
01dafcb5	168	auth_debug_add("%.100s, line %lu: missing end quote",
42f11eb2	169	file, linenum);
acc9d6d7	170	xfree(s);
acc9d6d7	171	goto bad_option;
38c295d6	172	}
38c295d6	173	s[i] = 0;
01dafcb5	174	auth_debug_add("Adding to environment: %.900s", s);
38c295d6	175	debug("Adding to environment: %.900s", s);
61e96248	176	opts++;
38c295d6	177	new_envstring = xmalloc(sizeof(struct envstring));
	178	new_envstring->s = s;
	179	new_envstring->next = custom_environment;
	180	custom_environment = new_envstring;
	181	goto next_option;
	182	}
	183	cp = "from=\"";
61e96248	184	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
61e96248	185	const char *remote_ip = get_remote_ipaddr();
61e96248	186	const char *remote_host = get_canonical_hostname(
c5a7d788	187	options.use_dns);
61e96248	188	char *patterns = xmalloc(strlen(opts) + 1);
01794848	189
61e96248	190	opts += strlen(cp);
38c295d6	191	i = 0;
61e96248	192	while (*opts) {
61e96248	193	if (*opts == '"')
38c295d6	194	break;
61e96248	195	if (*opts == '\\' && opts[1] == '"') {
61e96248	196	opts += 2;
38c295d6	197	patterns[i++] = '"';
	198	continue;
	199	}
61e96248	200	patterns[i++] = *opts++;
38c295d6	201	}
61e96248	202	if (!*opts) {
38c295d6	203	debug("%.100s, line %lu: missing end quote",
42f11eb2	204	file, linenum);
01dafcb5	205	auth_debug_add("%.100s, line %lu: missing end quote",
42f11eb2	206	file, linenum);
acc9d6d7	207	xfree(patterns);
acc9d6d7	208	goto bad_option;
38c295d6	209	}
38c295d6	210	patterns[i] = 0;
61e96248	211	opts++;
2cee8a25	212	if (match_host_and_ip(remote_host, remote_ip,
	213	patterns) != 1) {
	214	xfree(patterns);
bbe88b6d	215	logit("Authentication tried for %.100s with "
61e96248	216	"correct key but not from a permitted "
	217	"host (host=%.200s, ip=%.200s).",
	218	pw->pw_name, remote_host, remote_ip);
01dafcb5	219	auth_debug_add("Your host '%.200s' is not "
61e96248	220	"permitted to use this key for login.",
61e96248	221	remote_host);
38c295d6	222	/* deny access */
	223	return 0;
	224	}
2cee8a25	225	xfree(patterns);
38c295d6	226	/* Host name matches. */
	227	goto next_option;
	228	}
01794848	229	cp = "permitopen=\"";
01794848	230	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
3867aa0a	231	char host, p;
01794848	232	u_short port;
01794848	233	char *patterns = xmalloc(strlen(opts) + 1);
	234
	235	opts += strlen(cp);
	236	i = 0;
	237	while (*opts) {
	238	if (*opts == '"')
	239	break;
	240	if (*opts == '\\' && opts[1] == '"') {
	241	opts += 2;
	242	patterns[i++] = '"';
	243	continue;
	244	}
	245	patterns[i++] = *opts++;
	246	}
	247	if (!*opts) {
	248	debug("%.100s, line %lu: missing end quote",
	249	file, linenum);
3867aa0a	250	auth_debug_add("%.100s, line %lu: missing "
3867aa0a	251	"end quote", file, linenum);
01794848	252	xfree(patterns);
	253	goto bad_option;
	254	}
	255	patterns[i] = 0;
	256	opts++;
3867aa0a	257	p = patterns;
	258	host = hpdelim(&p);
	259	if (host == NULL \|\| strlen(host) >= NI_MAXHOST) {
	260	debug("%.100s, line %lu: Bad permitopen "
16d3d2bc	261	"specification <%.100s>", file, linenum,
3867aa0a	262	patterns);
01dafcb5	263	auth_debug_add("%.100s, line %lu: "
3867aa0a	264	"Bad permitopen specification", file,
3867aa0a	265	linenum);
01794848	266	xfree(patterns);
	267	goto bad_option;
	268	}
f8cc7664	269	host = cleanhostname(host);
f8cc7664	270	if (p == NULL \|\| (port = a2port(p)) == 0) {
3867aa0a	271	debug("%.100s, line %lu: Bad permitopen port "
3867aa0a	272	"<%.100s>", file, linenum, p ? p : "");
01dafcb5	273	auth_debug_add("%.100s, line %lu: "
ed787d14	274	"Bad permitopen port", file, linenum);
01794848	275	xfree(patterns);
	276	goto bad_option;
	277	}
b1ed8313	278	if (options.allow_tcp_forwarding)
ed787d14	279	channel_add_permitted_opens(host, port);
01794848	280	xfree(patterns);
	281	goto next_option;
	282	}
d20f3c9e	283	cp = "tunnel=\"";
	284	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
	285	char *tun = NULL;
	286	opts += strlen(cp);
	287	tun = xmalloc(strlen(opts) + 1);
	288	i = 0;
	289	while (*opts) {
	290	if (*opts == '"')
	291	break;
	292	tun[i++] = *opts++;
	293	}
	294	if (!*opts) {
	295	debug("%.100s, line %lu: missing end quote",
	296	file, linenum);
	297	auth_debug_add("%.100s, line %lu: missing end quote",
	298	file, linenum);
	299	xfree(tun);
	300	forced_tun_device = -1;
	301	goto bad_option;
	302	}
	303	tun[i] = 0;
	304	forced_tun_device = a2tun(tun, NULL);
	305	xfree(tun);
a4f24bf8	306	if (forced_tun_device == SSH_TUNID_ERR) {
d20f3c9e	307	debug("%.100s, line %lu: invalid tun device",
	308	file, linenum);
	309	auth_debug_add("%.100s, line %lu: invalid tun device",
	310	file, linenum);
	311	forced_tun_device = -1;
	312	goto bad_option;
	313	}
	314	auth_debug_add("Forced tun device: %d", forced_tun_device);
	315	opts++;
	316	goto next_option;
	317	}
38c295d6	318	next_option:
	319	/*
	320	* Skip the comma, and move to the next option
	321	* (or break out if there are no more).
	322	*/
61e96248	323	if (!*opts)
38c295d6	324	fatal("Bugs in auth-options.c option processing.");
61e96248	325	if (opts == ' ' \|\| opts == '\t')
38c295d6	326	break; /* End of options. */
61e96248	327	if (*opts != ',')
38c295d6	328	goto bad_option;
61e96248	329	opts++;
38c295d6	330	/* Process the next option. */
38c295d6	331	}
1853d1ef	332
1853d1ef	333	if (!use_privsep)
01dafcb5	334	auth_debug_send();
1853d1ef	335
38c295d6	336	/* grant access */
	337	return 1;
	338
	339	bad_option:
bbe88b6d	340	logit("Bad options in %.100s file, line %lu: %.50s",
61e96248	341	file, linenum, opts);
01dafcb5	342	auth_debug_add("Bad options in %.100s file, line %lu: %.50s",
61e96248	343	file, linenum, opts);
1853d1ef	344
1853d1ef	345	if (!use_privsep)
01dafcb5	346	auth_debug_send();
1853d1ef	347
38c295d6	348	/* deny access */
	349	return 0;
	350	}