[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 1.33 2005/12/08 18:34:11 reyk Exp $");

#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
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"
2c06c99b	13	RCSID("$OpenBSD: auth-options.c,v 1.33 2005/12/08 18:34:11 reyk Exp $");
3c0ef626	14
3c0ef626	15	#include "xmalloc.h"
	16	#include "match.h"
	17	#include "log.h"
	18	#include "canohost.h"
	19	#include "channels.h"
	20	#include "auth-options.h"
	21	#include "servconf.h"
	22	#include "misc.h"
700318f3	23	#include "monitor_wrap.h"
700318f3	24	#include "auth.h"
3c0ef626	25
	26	/* Flags set authorized_keys flags */
	27	int no_port_forwarding_flag = 0;
	28	int no_agent_forwarding_flag = 0;
	29	int no_x11_forwarding_flag = 0;
	30	int no_pty_flag = 0;
	31
	32	/* "command=" option. */
	33	char *forced_command = NULL;
	34
	35	/* "environment=" options. */
	36	struct envstring *custom_environment = NULL;
	37
2c06c99b	38	/* "tunnel=" option. */
	39	int forced_tun_device = -1;
	40
3c0ef626	41	extern ServerOptions options;
	42
	43	void
	44	auth_clear_options(void)
	45	{
	46	no_agent_forwarding_flag = 0;
	47	no_port_forwarding_flag = 0;
	48	no_pty_flag = 0;
	49	no_x11_forwarding_flag = 0;
	50	while (custom_environment) {
	51	struct envstring *ce = custom_environment;
	52	custom_environment = ce->next;
	53	xfree(ce->s);
	54	xfree(ce);
	55	}
	56	if (forced_command) {
	57	xfree(forced_command);
	58	forced_command = NULL;
	59	}
2c06c99b	60	forced_tun_device = -1;
3c0ef626	61	channel_clear_permitted_opens();
700318f3	62	auth_debug_reset();
3c0ef626	63	}
	64
	65	/*
	66	* return 1 if access is granted, 0 if not.
	67	* side effect: sets key option flags
	68	*/
	69	int
	70	auth_parse_options(struct passwd pw, char opts, char *file, u_long linenum)
	71	{
	72	const char *cp;
	73	int i;
	74
	75	/* reset options */
	76	auth_clear_options();
	77
	78	if (!opts)
	79	return 1;
	80
	81	while (opts && opts != ' ' && *opts != '\t') {
	82	cp = "no-port-forwarding";
	83	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
700318f3	84	auth_debug_add("Port forwarding disabled.");
3c0ef626	85	no_port_forwarding_flag = 1;
	86	opts += strlen(cp);
	87	goto next_option;
	88	}
	89	cp = "no-agent-forwarding";
	90	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
700318f3	91	auth_debug_add("Agent forwarding disabled.");
3c0ef626	92	no_agent_forwarding_flag = 1;
	93	opts += strlen(cp);
	94	goto next_option;
	95	}
	96	cp = "no-X11-forwarding";
	97	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
700318f3	98	auth_debug_add("X11 forwarding disabled.");
3c0ef626	99	no_x11_forwarding_flag = 1;
	100	opts += strlen(cp);
	101	goto next_option;
	102	}
	103	cp = "no-pty";
	104	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
700318f3	105	auth_debug_add("Pty allocation disabled.");
3c0ef626	106	no_pty_flag = 1;
	107	opts += strlen(cp);
	108	goto next_option;
	109	}
	110	cp = "command=\"";
	111	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
	112	opts += strlen(cp);
	113	forced_command = xmalloc(strlen(opts) + 1);
	114	i = 0;
	115	while (*opts) {
	116	if (*opts == '"')
	117	break;
	118	if (*opts == '\\' && opts[1] == '"') {
	119	opts += 2;
	120	forced_command[i++] = '"';
	121	continue;
	122	}
	123	forced_command[i++] = *opts++;
	124	}
	125	if (!*opts) {
	126	debug("%.100s, line %lu: missing end quote",
	127	file, linenum);
700318f3	128	auth_debug_add("%.100s, line %lu: missing end quote",
3c0ef626	129	file, linenum);
	130	xfree(forced_command);
	131	forced_command = NULL;
	132	goto bad_option;
	133	}
	134	forced_command[i] = 0;
700318f3	135	auth_debug_add("Forced command: %.900s", forced_command);
3c0ef626	136	opts++;
	137	goto next_option;
	138	}
	139	cp = "environment=\"";
41b2f314	140	if (options.permit_user_env &&
41b2f314	141	strncasecmp(opts, cp, strlen(cp)) == 0) {
3c0ef626	142	char *s;
	143	struct envstring *new_envstring;
	144
	145	opts += strlen(cp);
	146	s = xmalloc(strlen(opts) + 1);
	147	i = 0;
	148	while (*opts) {
	149	if (*opts == '"')
	150	break;
	151	if (*opts == '\\' && opts[1] == '"') {
	152	opts += 2;
	153	s[i++] = '"';
	154	continue;
	155	}
	156	s[i++] = *opts++;
	157	}
	158	if (!*opts) {
	159	debug("%.100s, line %lu: missing end quote",
	160	file, linenum);
700318f3	161	auth_debug_add("%.100s, line %lu: missing end quote",
3c0ef626	162	file, linenum);
	163	xfree(s);
	164	goto bad_option;
	165	}
	166	s[i] = 0;
700318f3	167	auth_debug_add("Adding to environment: %.900s", s);
3c0ef626	168	debug("Adding to environment: %.900s", s);
	169	opts++;
	170	new_envstring = xmalloc(sizeof(struct envstring));
	171	new_envstring->s = s;
	172	new_envstring->next = custom_environment;
	173	custom_environment = new_envstring;
	174	goto next_option;
	175	}
	176	cp = "from=\"";
	177	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
	178	const char *remote_ip = get_remote_ipaddr();
	179	const char *remote_host = get_canonical_hostname(
0fff78ff	180	options.use_dns);
3c0ef626	181	char *patterns = xmalloc(strlen(opts) + 1);
	182
	183	opts += strlen(cp);
	184	i = 0;
	185	while (*opts) {
	186	if (*opts == '"')
	187	break;
	188	if (*opts == '\\' && opts[1] == '"') {
	189	opts += 2;
	190	patterns[i++] = '"';
	191	continue;
	192	}
	193	patterns[i++] = *opts++;
	194	}
	195	if (!*opts) {
	196	debug("%.100s, line %lu: missing end quote",
	197	file, linenum);
700318f3	198	auth_debug_add("%.100s, line %lu: missing end quote",
3c0ef626	199	file, linenum);
	200	xfree(patterns);
	201	goto bad_option;
	202	}
	203	patterns[i] = 0;
	204	opts++;
	205	if (match_host_and_ip(remote_host, remote_ip,
	206	patterns) != 1) {
	207	xfree(patterns);
0fff78ff	208	logit("Authentication tried for %.100s with "
3c0ef626	209	"correct key but not from a permitted "
	210	"host (host=%.200s, ip=%.200s).",
	211	pw->pw_name, remote_host, remote_ip);
700318f3	212	auth_debug_add("Your host '%.200s' is not "
3c0ef626	213	"permitted to use this key for login.",
	214	remote_host);
	215	/* deny access */
	216	return 0;
	217	}
	218	xfree(patterns);
	219	/* Host name matches. */
	220	goto next_option;
	221	}
	222	cp = "permitopen=\"";
	223	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
996d5e62	224	char host, p;
3c0ef626	225	u_short port;
	226	char *patterns = xmalloc(strlen(opts) + 1);
	227
	228	opts += strlen(cp);
	229	i = 0;
	230	while (*opts) {
	231	if (*opts == '"')
	232	break;
	233	if (*opts == '\\' && opts[1] == '"') {
	234	opts += 2;
	235	patterns[i++] = '"';
	236	continue;
	237	}
	238	patterns[i++] = *opts++;
	239	}
	240	if (!*opts) {
	241	debug("%.100s, line %lu: missing end quote",
	242	file, linenum);
996d5e62	243	auth_debug_add("%.100s, line %lu: missing "
996d5e62	244	"end quote", file, linenum);
3c0ef626	245	xfree(patterns);
	246	goto bad_option;
	247	}
	248	patterns[i] = 0;
	249	opts++;
996d5e62	250	p = patterns;
	251	host = hpdelim(&p);
	252	if (host == NULL \|\| strlen(host) >= NI_MAXHOST) {
	253	debug("%.100s, line %lu: Bad permitopen "
dec6d9fe	254	"specification <%.100s>", file, linenum,
996d5e62	255	patterns);
700318f3	256	auth_debug_add("%.100s, line %lu: "
996d5e62	257	"Bad permitopen specification", file,
996d5e62	258	linenum);
3c0ef626	259	xfree(patterns);
	260	goto bad_option;
	261	}
dec6d9fe	262	host = cleanhostname(host);
dec6d9fe	263	if (p == NULL \|\| (port = a2port(p)) == 0) {
996d5e62	264	debug("%.100s, line %lu: Bad permitopen port "
996d5e62	265	"<%.100s>", file, linenum, p ? p : "");
700318f3	266	auth_debug_add("%.100s, line %lu: "
3c0ef626	267	"Bad permitopen port", file, linenum);
	268	xfree(patterns);
	269	goto bad_option;
	270	}
	271	if (options.allow_tcp_forwarding)
	272	channel_add_permitted_opens(host, port);
	273	xfree(patterns);
	274	goto next_option;
	275	}
2c06c99b	276	cp = "tunnel=\"";
	277	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
	278	char *tun = NULL;
	279	opts += strlen(cp);
	280	tun = xmalloc(strlen(opts) + 1);
	281	i = 0;
	282	while (*opts) {
	283	if (*opts == '"')
	284	break;
	285	tun[i++] = *opts++;
	286	}
	287	if (!*opts) {
	288	debug("%.100s, line %lu: missing end quote",
	289	file, linenum);
	290	auth_debug_add("%.100s, line %lu: missing end quote",
	291	file, linenum);
	292	xfree(tun);
	293	forced_tun_device = -1;
	294	goto bad_option;
	295	}
	296	tun[i] = 0;
	297	forced_tun_device = a2tun(tun, NULL);
	298	xfree(tun);
	299	if (forced_tun_device == SSH_TUNID_ERR) {
	300	debug("%.100s, line %lu: invalid tun device",
	301	file, linenum);
	302	auth_debug_add("%.100s, line %lu: invalid tun device",
	303	file, linenum);
	304	forced_tun_device = -1;
	305	goto bad_option;
	306	}
	307	auth_debug_add("Forced tun device: %d", forced_tun_device);
	308	opts++;
	309	goto next_option;
	310	}
3c0ef626	311	next_option:
	312	/*
	313	* Skip the comma, and move to the next option
	314	* (or break out if there are no more).
	315	*/
	316	if (!*opts)
	317	fatal("Bugs in auth-options.c option processing.");
	318	if (opts == ' ' \|\| opts == '\t')
	319	break; /* End of options. */
	320	if (*opts != ',')
	321	goto bad_option;
	322	opts++;
	323	/* Process the next option. */
	324	}
700318f3	325
	326	if (!use_privsep)
	327	auth_debug_send();
	328
3c0ef626	329	/* grant access */
	330	return 1;
	331
	332	bad_option:
0fff78ff	333	logit("Bad options in %.100s file, line %lu: %.50s",
3c0ef626	334	file, linenum, opts);
700318f3	335	auth_debug_add("Bad options in %.100s file, line %lu: %.50s",
3c0ef626	336	file, linenum, opts);
700318f3	337
	338	if (!use_privsep)
	339	auth_debug_send();
	340
3c0ef626	341	/* deny access */
	342	return 0;
	343	}