[openssh.git] / 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 1.15 2001/03/16 19:06:28 markus 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"

/* 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) {
			int mname, mip;
			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++;
			/*
			 * Deny access if we get a negative
			 * match for the hostname or the ip
			 * or if we get not match at all
			 */
			mname = match_hostname(remote_host, patterns,
			    strlen(patterns));
			mip = match_hostname(remote_ip, patterns,
			    strlen(patterns));
			xfree(patterns);
			if (mname == -1 || mip == -1 ||
			    (mname != 1 && mip != 1)) {
				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;
			}
			/* Host name matches. */
			goto next_option;
		}
		cp = "permitopen=\"";
		if (strncasecmp(opts, cp, strlen(cp)) == 0) {
			u_short port;
			char *c, *ep;
			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++;
			c = strchr(patterns, ':');
			if (c == NULL) {
				debug("%.100s, line %lu: permitopen: missing colon <%.100s>",
				    file, linenum, patterns);
				packet_send_debug("%.100s, line %lu: missing colon",
				    file, linenum);
				xfree(patterns);
				goto bad_option;
			}
			*c = 0;
			c++;
			port = strtol(c, &ep, 0);
			if (c == ep) {
				debug("%.100s, line %lu: permitopen: missing port <%.100s>",
				    file, linenum, patterns);
				packet_send_debug("%.100s, line %lu: missing port",
				    file, linenum);
				xfree(patterns);
				goto bad_option;
			}
			channel_add_permitted_opens(patterns, 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
bcbf86ec	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
bcbf86ec	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
38c295d6	12	#include "includes.h"
01794848	13	RCSID("$OpenBSD: auth-options.c,v 1.15 2001/03/16 19:06:28 markus Exp $");
38c295d6	14
38c295d6	15	#include "packet.h"
	16	#include "xmalloc.h"
	17	#include "match.h"
42f11eb2	18	#include "log.h"
42f11eb2	19	#include "canohost.h"
01794848	20	#include "channels.h"
42f11eb2	21	#include "auth-options.h"
61e96248	22	#include "servconf.h"
38c295d6	23
	24	/* Flags set authorized_keys flags */
	25	int no_port_forwarding_flag = 0;
	26	int no_agent_forwarding_flag = 0;
	27	int no_x11_forwarding_flag = 0;
	28	int no_pty_flag = 0;
	29
	30	/* "command=" option. */
	31	char *forced_command = NULL;
	32
	33	/* "environment=" options. */
	34	struct envstring *custom_environment = NULL;
	35
61e96248	36	extern ServerOptions options;
61e96248	37
94ec8c6b	38	void
	39	auth_clear_options(void)
	40	{
	41	no_agent_forwarding_flag = 0;
	42	no_port_forwarding_flag = 0;
	43	no_pty_flag = 0;
	44	no_x11_forwarding_flag = 0;
	45	while (custom_environment) {
	46	struct envstring *ce = custom_environment;
	47	custom_environment = ce->next;
	48	xfree(ce->s);
	49	xfree(ce);
	50	}
	51	if (forced_command) {
	52	xfree(forced_command);
	53	forced_command = NULL;
	54	}
01794848	55	channel_clear_permitted_opens();
94ec8c6b	56	}
94ec8c6b	57
42f11eb2	58	/*
	59	* return 1 if access is granted, 0 if not.
	60	* side effect: sets key option flags
	61	*/
38c295d6	62	int
61e96248	63	auth_parse_options(struct passwd pw, char opts, char *file, u_long linenum)
38c295d6	64	{
38c295d6	65	const char *cp;
01794848	66	int i;
94ec8c6b	67
	68	/* reset options */
	69	auth_clear_options();
	70
e0b2cf6b	71	if (!opts)
	72	return 1;
	73
61e96248	74	while (opts && opts != ' ' && *opts != '\t') {
38c295d6	75	cp = "no-port-forwarding";
61e96248	76	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
38c295d6	77	packet_send_debug("Port forwarding disabled.");
38c295d6	78	no_port_forwarding_flag = 1;
61e96248	79	opts += strlen(cp);
38c295d6	80	goto next_option;
	81	}
	82	cp = "no-agent-forwarding";
61e96248	83	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
38c295d6	84	packet_send_debug("Agent forwarding disabled.");
38c295d6	85	no_agent_forwarding_flag = 1;
61e96248	86	opts += strlen(cp);
38c295d6	87	goto next_option;
	88	}
	89	cp = "no-X11-forwarding";
61e96248	90	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
38c295d6	91	packet_send_debug("X11 forwarding disabled.");
38c295d6	92	no_x11_forwarding_flag = 1;
61e96248	93	opts += strlen(cp);
38c295d6	94	goto next_option;
	95	}
	96	cp = "no-pty";
61e96248	97	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
38c295d6	98	packet_send_debug("Pty allocation disabled.");
38c295d6	99	no_pty_flag = 1;
61e96248	100	opts += strlen(cp);
38c295d6	101	goto next_option;
	102	}
	103	cp = "command=\"";
61e96248	104	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
61e96248	105	opts += strlen(cp);
61e96248	106	forced_command = xmalloc(strlen(opts) + 1);
38c295d6	107	i = 0;
61e96248	108	while (*opts) {
61e96248	109	if (*opts == '"')
38c295d6	110	break;
61e96248	111	if (*opts == '\\' && opts[1] == '"') {
61e96248	112	opts += 2;
38c295d6	113	forced_command[i++] = '"';
	114	continue;
	115	}
61e96248	116	forced_command[i++] = *opts++;
38c295d6	117	}
61e96248	118	if (!*opts) {
38c295d6	119	debug("%.100s, line %lu: missing end quote",
42f11eb2	120	file, linenum);
38c295d6	121	packet_send_debug("%.100s, line %lu: missing end quote",
42f11eb2	122	file, linenum);
acc9d6d7	123	xfree(forced_command);
	124	forced_command = NULL;
	125	goto bad_option;
38c295d6	126	}
	127	forced_command[i] = 0;
	128	packet_send_debug("Forced command: %.900s", forced_command);
61e96248	129	opts++;
38c295d6	130	goto next_option;
	131	}
	132	cp = "environment=\"";
61e96248	133	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
38c295d6	134	char *s;
38c295d6	135	struct envstring *new_envstring;
01794848	136
61e96248	137	opts += strlen(cp);
61e96248	138	s = xmalloc(strlen(opts) + 1);
38c295d6	139	i = 0;
61e96248	140	while (*opts) {
61e96248	141	if (*opts == '"')
38c295d6	142	break;
61e96248	143	if (*opts == '\\' && opts[1] == '"') {
61e96248	144	opts += 2;
38c295d6	145	s[i++] = '"';
	146	continue;
	147	}
61e96248	148	s[i++] = *opts++;
38c295d6	149	}
61e96248	150	if (!*opts) {
38c295d6	151	debug("%.100s, line %lu: missing end quote",
42f11eb2	152	file, linenum);
38c295d6	153	packet_send_debug("%.100s, line %lu: missing end quote",
42f11eb2	154	file, linenum);
acc9d6d7	155	xfree(s);
acc9d6d7	156	goto bad_option;
38c295d6	157	}
	158	s[i] = 0;
	159	packet_send_debug("Adding to environment: %.900s", s);
	160	debug("Adding to environment: %.900s", s);
61e96248	161	opts++;
38c295d6	162	new_envstring = xmalloc(sizeof(struct envstring));
	163	new_envstring->s = s;
	164	new_envstring->next = custom_environment;
	165	custom_environment = new_envstring;
	166	goto next_option;
	167	}
	168	cp = "from=\"";
61e96248	169	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
38c295d6	170	int mname, mip;
61e96248	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);
01794848	175
61e96248	176	opts += strlen(cp);
38c295d6	177	i = 0;
61e96248	178	while (*opts) {
61e96248	179	if (*opts == '"')
38c295d6	180	break;
61e96248	181	if (*opts == '\\' && opts[1] == '"') {
61e96248	182	opts += 2;
38c295d6	183	patterns[i++] = '"';
	184	continue;
	185	}
61e96248	186	patterns[i++] = *opts++;
38c295d6	187	}
61e96248	188	if (!*opts) {
38c295d6	189	debug("%.100s, line %lu: missing end quote",
42f11eb2	190	file, linenum);
38c295d6	191	packet_send_debug("%.100s, line %lu: missing end quote",
42f11eb2	192	file, linenum);
acc9d6d7	193	xfree(patterns);
acc9d6d7	194	goto bad_option;
38c295d6	195	}
38c295d6	196	patterns[i] = 0;
61e96248	197	opts++;
38c295d6	198	/*
	199	* Deny access if we get a negative
	200	* match for the hostname or the ip
	201	* or if we get not match at all
	202	*/
61e96248	203	mname = match_hostname(remote_host, patterns,
	204	strlen(patterns));
	205	mip = match_hostname(remote_ip, patterns,
	206	strlen(patterns));
38c295d6	207	xfree(patterns);
	208	if (mname == -1 \|\| mip == -1 \|\|
	209	(mname != 1 && mip != 1)) {
61e96248	210	log("Authentication tried for %.100s with "
	211	"correct key but not from a permitted "
	212	"host (host=%.200s, ip=%.200s).",
	213	pw->pw_name, remote_host, remote_ip);
	214	packet_send_debug("Your host '%.200s' is not "
	215	"permitted to use this key for login.",
	216	remote_host);
38c295d6	217	/* deny access */
	218	return 0;
	219	}
	220	/* Host name matches. */
	221	goto next_option;
	222	}
01794848	223	cp = "permitopen=\"";
	224	if (strncasecmp(opts, cp, strlen(cp)) == 0) {
	225	u_short port;
	226	char c, ep;
	227	char *patterns = xmalloc(strlen(opts) + 1);
	228
	229	opts += strlen(cp);
	230	i = 0;
	231	while (*opts) {
	232	if (*opts == '"')
	233	break;
	234	if (*opts == '\\' && opts[1] == '"') {
	235	opts += 2;
	236	patterns[i++] = '"';
	237	continue;
	238	}
	239	patterns[i++] = *opts++;
	240	}
	241	if (!*opts) {
	242	debug("%.100s, line %lu: missing end quote",
	243	file, linenum);
	244	packet_send_debug("%.100s, line %lu: missing end quote",
	245	file, linenum);
	246	xfree(patterns);
	247	goto bad_option;
	248	}
	249	patterns[i] = 0;
	250	opts++;
	251	c = strchr(patterns, ':');
	252	if (c == NULL) {
	253	debug("%.100s, line %lu: permitopen: missing colon <%.100s>",
	254	file, linenum, patterns);
	255	packet_send_debug("%.100s, line %lu: missing colon",
	256	file, linenum);
	257	xfree(patterns);
	258	goto bad_option;
	259	}
	260	*c = 0;
	261	c++;
	262	port = strtol(c, &ep, 0);
	263	if (c == ep) {
	264	debug("%.100s, line %lu: permitopen: missing port <%.100s>",
	265	file, linenum, patterns);
	266	packet_send_debug("%.100s, line %lu: missing port",
	267	file, linenum);
	268	xfree(patterns);
	269	goto bad_option;
	270	}
	271	channel_add_permitted_opens(patterns, port);
	272	xfree(patterns);
	273	goto next_option;
	274	}
38c295d6	275	next_option:
	276	/*
	277	* Skip the comma, and move to the next option
	278	* (or break out if there are no more).
	279	*/
61e96248	280	if (!*opts)
38c295d6	281	fatal("Bugs in auth-options.c option processing.");
61e96248	282	if (opts == ' ' \|\| opts == '\t')
38c295d6	283	break; /* End of options. */
61e96248	284	if (*opts != ',')
38c295d6	285	goto bad_option;
61e96248	286	opts++;
38c295d6	287	/* Process the next option. */
	288	}
	289	/* grant access */
	290	return 1;
	291
	292	bad_option:
	293	log("Bad options in %.100s file, line %lu: %.50s",
61e96248	294	file, linenum, opts);
38c295d6	295	packet_send_debug("Bad options in %.100s file, line %lu: %.50s",
61e96248	296	file, linenum, opts);
38c295d6	297	/* deny access */
	298	return 0;
	299	}