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source: trunk/src/trustfile.c@ 194

Last change on this file since 194 was 192, checked in by katerina, 16 years ago
Fixes for cygwin, and improved error diagnostics (tickets #126, #127, #128).
File size: 27.4 KB

Rev	Line
[1]	1	/* debug problems */
	2	/* #define TRUST_DEBUG */
	3
	4	/* switch off full check */
	5	/* #define TEST_ONLY */
	6
	7	/* standalone */
	8	/* #define TRUST_MAIN */
	9	/* $(CC) -DTRUST_MAIN -DSL_ALWAYS_TRUSTED=... */
	10
	11	/* LINTLIBRARY */
	12	/*
	13	* This is the file with all the library routines in it
	14	*
	15	* Author information:
	16	* Matt Bishop
	17	* Department of Computer Science
	18	* University of California at Davis
	19	* Davis, CA 95616-8562
	20	* phone (916) 752-8060
	21	* email bishop@cs.ucdavis.edu
	22	*
	23	* This code is placed in the public domain. I do ask that
	24	* you keep my name associated with it, that you not represent
	25	* it as written by you, and that you preserve these comments.
	26	* This software is provided "as is" and without any guarantees
	27	* of any sort.
	28	*
	29	* Compilation notes:
	30	* * this does NOT use malloc(3), but fixed storage. this means we
	31	* do lots of bounds checking, but it still is faster, and smaller,
	32	* than forcing inclusion of malloc. All buffers etc. are of size
	33	* MAXFILENAME (defined in trustfile.h); to get more room, recompile
	34	* with this set larger.
	35	* * if you support the following directory semantics, define STICKY;
	36	* otherwise, undefine it
	37	* "if a directory is both world-writeable AND has the sticky bit
	38	* set, then ONLY the owner of an existing file may delete it"
	39	* On some systems (eg, IRIX), you can delete the file under these
	40	* conditions if the file is world writeable. Foor our purposes,
	41	* this is irrelevant since if the file is world-writeable it is
	42	* untrustworthy; either it can be replaced with another file (the
	43	* IRIX version) or it can be altered (all versions).
	44	* if this is true and STICKY is not set, the sticky bit is ignored
	45	* and the directory will be flagged as untrustworthy, even when only
	46	* a trusted user could delete the file
	47	* * this uses a library call to get the name of the current working
	48	* directory. Define the following to get the various versions:
	49	* GETCWD for Solaris 2.x, SunOS 4.1.x, IRIX 5.x
	50	* char getcwd(char buf, int bufsz);
	51	* where buf is a buffer for the path name, and bufsz is
	52	* the size of the buffer; if the size if too small, you
	53	* get an error return (NULL)
	54	* GETWD for Ultrix 4.4
	55	* char getwd(char buf)
	56	* where buf is a buffer for the path name, and it is
	57	* assumed to be at lease as big as MAXPATHLEN.
	58	* * IMPORTANT NOTE *
	59	* Ultrix supports getcwd as well, but it uses popen to
	60	* run the command "pwd" (according to the manual). This
	61	* means it's vulnerable to a number of attacks if used
	62	* in a privileged program. YOU DON'T WANT THIS.
	63	* * the debugging flag DEBUG prints out each step of the file name
	64	* checking, as well as info on symbolic links (if S_IFLNK defined),
	65	* file name canonicalization, and user, group, and permission for
	66	* each file or directory; this is useful if you want to be sure
	67	* you're checking the right file
	68	*
	69	* Version information:
	70	* 1.0 December 28, 1995 Matt Bishop
	71	*
	72	* 2.0 March 26, 2000 Rainer Wichmann -- adapted for slib.
	73	*/
	74
	75	/* --- Why strcpy is safe here: ---- */
	76
	77	/* The input path is checked once, and then either shortened [in dirz()],
	78	* or safely expanded (symlinks) with bound checking.
	79	* I.e., the path length can never exceed (MAXFILENAME-1), while the path
	80	* is always copied between buffers of length MAXFILENAME.
	81	*/
	82
	83	#ifndef TRUST_MAIN
	84	#include "config_xor.h"
	85	#include "sh_calls.h"
	86	#else
	87	#define UID_CAST long
	88	#endif
	89
	90	#include <stdio.h>
	91	#include <stdlib.h>
	92	#include <sys/types.h>
	93	#include <sys/stat.h>
	94	#include <grp.h>
	95	#include <pwd.h>
	96	#include <string.h>
	97	#include <unistd.h>
	98
	99
	100	#ifndef TRUST_MAIN
[131]	101
[1]	102	#include "slib.h"
	103	#define SH_NEED_PWD_GRP 1
	104	#include "sh_static.h"
[137]	105	#include "sh_pthread.h"
[1]	106
	107	#else
	108
	109	#define sh_getgrgid getgrgid
[131]	110	#define sh_getgrgid_r getgrgid_r
[1]	111	#define sh_getpwnam getpwnam
[131]	112	#define sh_getpwnam_r getpwnam_r
[1]	113	#define sh_getpwuid getpwuid
[131]	114	#define sh_getpwuid_r getpwuid_r
	115	#define sh_getpwent getpwent
[1]	116	#define sh_endpwent endpwent
	117
	118	#define TRUST_DEBUG
	119	#define SL_FALSE 0
	120	#define SL_TRUE 1
	121	#define SL_ENTER(string)
	122	#define SL_IRETURN(a, b) return a
	123	#define retry_lstat(a,b,c,d) lstat(c,d)
	124	#define _(string) string
	125	#define N_(string) string
	126	#define MAXFILENAME 4096
	127	static int sl_errno = 0;
	128	#define SL_ENONE 0
	129	#define SL_ENULL -1024 /* Invalid use of NULL pointer. */
	130	#define SL_ERANGE -1025 /* Argument out of range. */
	131	#define SL_ETRUNC -1026 /* Result truncated. */
	132	#define SL_EINTERNAL -1028 /* Internal error. */
	133	#define SL_EBADFILE -1030 /* File access error. Check errno. */
	134	#define SL_EBADNAME -1040 /* Invalid name. */
	135	#define SL_ESTAT -1041 /* stat of file failed. Check errno. */
	136	#define SL_EBADUID -1050 /* Owner not trustworthy. */
	137	#define SL_EBADGID -1051 /* Group writeable and not trustworthy.*/
	138	#define SL_EBADOTH -1052 /* World writeable. */
	139
	140	#endif
	141
	142
	143	#if defined(__linux__) \|\| defined(__FreeBSD__)
	144	#define STICKY
	145	#endif
	146
	147	#undef FIL__
	148	#define FIL__ _("trustfile.c")
	149
	150	/*
	151	* the get current working directory function
	152	* every version of UNIX seems to have its own
	153	* idea of how to do this, so we group them by
	154	* arguments ...
	155	* all must return a pointer to the right name
	156	*/
	157
	158
	159	#ifndef TRUST_MAIN
	160
	161	#if defined(HAVE_GETCWD) && !defined(HAVE_BROKEN_GETCWD)
	162	#define CURDIR(buf,nbuf) getcwd((buf), (nbuf))
	163	#elif defined(HAVE_GETWD)
	164	#define CURDIR(buf,nbuf) getwd((buf))
	165	#endif
	166
	167	#else
	168
	169	#define CURDIR(buf,nbuf) getcwd((buf), (nbuf))
	170
	171	#endif
	172
	173
	174
	175	/*
	176	* this checks to see if there are symbolic links
	177	* assumes the link bit in the protection mask is called S_IFLNK
	178	* (seems to be true on all UNIXes with them)
	179	*/
	180	#ifndef S_IFLNK
	181	#define lstat stat
	182	#endif
	183
	184
	185	/*
	186	* these are useful global variables
	187	*
	188	* first set: who you gonna trust, by default?
	189	* if the user does not specify a trusted or untrusted set of users,
	190	* all users are considered untrusted EXCEPT:
	191	* UID 0 -- root as root can do anything on most UNIX systems, this
	192	* seems reasonable
	193	* tf_euid -- programmer-selectable UID
	194	* if the caller specifies a specific UID by putting
	195	* it in this variable, it will be trusted; this is
	196	* typically used to trust the effective UID of the
	197	* process (note: NOT the real UID, which will cause all
	198	* sorts of problems!) By default, this is set to -1,
	199	* so if it's not set, root is the only trusted user
	200	*/
	201
	202	/* modified Tue Feb 22 10:36:44 NFT 2000 Rainer Wichmann */
	203
	204
	205	#ifndef SL_ALWAYS_TRUSTED
	206	#define SL_ALWAYS_TRUSTED 0
	207	#endif
	208	static uid_t test_rootonly[] = { SL_ALWAYS_TRUSTED };
	209
	210	#define tf_uid_neg ((uid_t)-1)
	211
	212	uid_t rootonly[] = { SL_ALWAYS_TRUSTED,
	213	tf_uid_neg, tf_uid_neg, tf_uid_neg, tf_uid_neg,
	214	tf_uid_neg, tf_uid_neg, tf_uid_neg, tf_uid_neg,
	215	tf_uid_neg, tf_uid_neg, tf_uid_neg, tf_uid_neg,
	216	tf_uid_neg, tf_uid_neg, tf_uid_neg, tf_uid_neg };
	217
	218	uid_t tf_euid = tf_uid_neg;
	219	int EUIDSLOT = sizeof(test_rootonly)/sizeof(uid_t);
	220	int ORIG_EUIDSLOT = sizeof(test_rootonly)/sizeof(uid_t);
	221
	222	char tf_path[MAXFILENAME]; /* error path for trust function */
	223	uid_t tf_baduid;
	224	gid_t tf_badgid;
	225
	226	static
	227	int dirz(char *path)
	228	{
	229	register char p = path;/ points to rest of path to clean up */
	230	register char q; / temp pointer for skipping over stuff */
	231
	232	static char swp[MAXFILENAME];
	233
	234	SL_ENTER(_("dirz"));
	235	/*
	236	* standard error checking
	237	*/
	238	if (path == NULL)
	239	SL_IRETURN(SL_ENULL, _("dirz"));
	240	if (path[0] == '.')
	241	SL_IRETURN(SL_EINTERNAL, _("dirz"));
	242
	243
	244	/*
	245	* loop over the path name until everything is checked
	246	*/
	247	while(*p)
	248	{
	249	/* skip
	250	*/
	251	if (*p != '/')
	252	{
	253	p++;
	254	continue;
	255	}
	256
	257	/* "/./" or "/."
	258	*/
	259	if (p[1] == '.' && (p[2] == '/' \|\| p[2] == '\0'))
	260	{
	261	/* yes -- delete "/."
	262	*/
	263	(void) strcpy(swp, &p[2]); /* known to fit */
	264	(void) strcpy(p, swp); /* known to fit */
	265
	266	/* special case "/." as full path name
	267	*/
	268	if (p == path && *p == '\0')
	269	{
	270	*p++ = '/';
	271	*p = '\0';
	272	}
	273	}
	274
	275	/* "//"
	276	*/
	277	else if (p[1] == '/')
	278	{
	279	/* yes -- skip
	280	*/
	281	for(q = &p[2]; *q == '/'; q++)
	282	;
	283	(void) strcpy(swp, q); /* known to fit */
	284	(void) strcpy(&p[1], swp); /* known to fit */
	285	}
	286
	287	/* "/../" or "/.."
	288	*/
	289	else if (p[1] == '.' && p[2] == '.' && (p[3] == '/' \|\| p[3] == '\0'))
	290	{
	291	/* yes -- if it's root, delete .. only
	292	*/
	293	if (p == path)
	294	{
	295	(void) strcpy(swp, &p[3]); /* known to fit */
	296	(void) strcpy(p, swp); /* known to fit */
	297	}
	298	else
	299	{
	300	/* back up over previous component
	301	*/
	302	q = p - 1;
	303	while(q != path && *q != '/')
	304	q--;
	305	/* now wipe it out
	306	*/
	307	(void) strcpy(swp, &p[3]); /* known to fit */
	308	(void) strcpy(q, swp); /* known to fit */
	309	p = q;
	310	}
	311	}
	312	else
	313	p++;
	314	}
	315	SL_IRETURN(SL_ENONE, _("dirz"));
	316	}
	317
	318
	319
	320	/* not static to circumvent stupid gcc 4 bug */
[183]	321	int getfname(const char fname, char rbuf, int rsz)
[1]	322	{
	323	#ifndef TRUST_MAIN
	324	register int status;
	325	#endif
	326
	327	SL_ENTER(_("getfname"));
	328	/*
	329	* do the initial checking
	330	* NULL pointer
	331	*/
	332	if (fname == NULL \|\| rbuf == NULL)
	333	SL_IRETURN(SL_ENULL, _("getfname"));
	334	if (rsz <= 0)
	335	SL_IRETURN(SL_ERANGE, _("getfname"));
	336
	337
	338	/* already a full path name */
	339	if (*fname == '/')
	340	rbuf[0] = '\0';
	341	else
	342	{
	343	if (CURDIR(rbuf, rsz) == NULL)
	344	{
	345	#ifdef TRUST_DEBUG
	346	fprintf(stderr, "trustfile: getcwd failed\n");
	347	#endif
	348	SL_IRETURN(SL_EBADNAME, _("getfname"));
	349	}
	350	}
	351
	352	/*
	353	* append the file name and reduce
	354	*/
	355	if (fname != NULL && *fname != '\0')
	356	{
	357	#ifndef TRUST_MAIN
	358	status = sl_strlcat(rbuf, "/", rsz);
	359	if (status == SL_ENONE)
	360	status = sl_strlcat(rbuf, fname, rsz);
	361	if (status != SL_ENONE)
	362	SL_IRETURN(status, _("getfname"));
	363	#else
	364	strncat(rbuf, "/", rsz-strlen(rbuf));
	365	strncat(rbuf, fname, rsz-strlen(rbuf));
	366	#endif
	367	}
	368	SL_IRETURN(dirz(rbuf), _("getfname"));
	369	}
	370
	371	static
	372	int isin(uid_t n, uid_t *list)
	373	{
	374	SL_ENTER(_("isin"));
	375	if (list == NULL)
	376	SL_IRETURN(SL_FALSE, _("isin"));
	377
	378	while(list != tf_uid_neg && list != n)
	379	{
	380	#ifdef TRUST_DEBUG
	381	fprintf (stderr,
	382	"trustfile: owner_uid=%ld, trusted uid=%ld, no match\n",
	383	(UID_CAST) n, (UID_CAST) *list);
	384	#endif
	385	list++;
	386	}
	387
	388	if (*list == tf_uid_neg)
	389	{
	390	#ifdef TRUST_DEBUG
	391	fprintf (stderr,
	392	"trustfile: owner_uid=%ld, no match with any trusted user --> ERROR\n",
	393	(UID_CAST) n);
	394	#endif
	395	SL_IRETURN(SL_FALSE, _("isin"));
	396	}
	397
	398	#ifdef TRUST_DEBUG
	399	fprintf (stderr,
	400	"trustfile: owner_uid=%ld, trusted_uid=%ld, match found --> OK\n",
	401	(UID_CAST)n, (UID_CAST)*list);
	402	#endif
	403	SL_IRETURN(SL_TRUE, _("isin"));
	404	}
	405
	406	/* comment added by R. Wichmann
	407	* RETURN TRUE if ANYONE in ulist is group member
	408	*/
	409	/* not static to circumvent stupid gcc 4 bug */
	410	int isingrp(gid_t grp, uid_t *ulist)
	411	{
[137]	412	struct passwd w; / info about group member */
[1]	413	register uid_t u; / points to current ulist member */
	414	register char *p; / points to current group member */
[137]	415	struct group g; / pointer to group information */
[1]	416
[131]	417	#if defined(HAVE_PTHREAD) && defined (_POSIX_THREAD_SAFE_FUNCTIONS) && defined(HAVE_GETGRGID_R)
	418	struct group gr;
	419	char buffer[SH_GRBUF_SIZE];
	420	struct passwd pwd;
	421	char pbuffer[SH_PWBUF_SIZE];
	422	#endif
	423
[1]	424	SL_ENTER(_("isingrp"));
	425
[131]	426	#if defined(HAVE_PTHREAD) && defined (_POSIX_THREAD_SAFE_FUNCTIONS) && defined(HAVE_GETGRGID_R)
	427	sh_getgrgid_r(grp, &gr, buffer, sizeof(buffer), &g);
	428	#else
	429	g = sh_getgrgid(grp);
	430	#endif
	431
	432	if (g == NULL)
[1]	433	{
	434	SL_IRETURN(SL_FALSE, _("isingrp") );
	435	}
	436	/*
	437	if(g->gr_mem == NULL \|\| g->gr_mem[0] == NULL )
	438	SL_IRETURN(SL_FALSE, _("isingrp") );
	439	*/
	440
	441	/* this will return at the first match
	442	*/
	443	for(p = g->gr_mem; *p != NULL; p++)
	444	{
	445	for(u = ulist; *u != tf_uid_neg; u++)
	446	{
	447	/* map user name to UID and compare */
[131]	448	#if defined(HAVE_PTHREAD) && defined (_POSIX_THREAD_SAFE_FUNCTIONS) && defined(HAVE_GETPWNAM_R)
	449	sh_getpwnam_r(*p, &pwd, pbuffer, sizeof(pbuffer), &w);
	450	#else
	451	w = sh_getpwnam(*p);
	452	#endif
	453
[1]	454	#ifdef TRUST_MAIN
[131]	455	if (w != NULL && *u == (uid_t)(w->pw_uid) )
[1]	456	SL_IRETURN(SL_TRUE, _("isingrp"));
	457	#else
[131]	458	if (w != NULL && *u == (uid_t)(w->pw_uid) )
[1]	459	{
	460	SL_IRETURN(SL_TRUE, _("isingrp"));
	461	}
	462	#endif
	463	}
	464	}
	465	/* added by R. Wichmann Fri Mar 30 08:16:14 CEST 2001:
	466	* a user can have a GID but no entry in /etc/group
	467	*/
	468	for(u = ulist; *u != tf_uid_neg; u++)
	469	{
[131]	470	#if defined(HAVE_PTHREAD) && defined (_POSIX_THREAD_SAFE_FUNCTIONS) && defined(HAVE_GETPWUID_R)
	471	sh_getpwuid_r(*u, &pwd, pbuffer, sizeof(pbuffer), &w);
	472	#else
	473	w = sh_getpwuid(*u);
	474	#endif
[1]	475	#ifdef TRUST_MAIN
[131]	476	if (w != NULL && grp == (gid_t)(w->pw_gid) )
[1]	477	SL_IRETURN(SL_TRUE, _("isingrp"));
	478	#else
[131]	479	if (w != NULL && grp == (gid_t)(w->pw_gid) )
[1]	480	{
	481	SL_IRETURN(SL_TRUE, _("isingrp"));
	482	}
	483	#endif
	484	}
	485
	486	SL_IRETURN(SL_FALSE, _("isingrp"));
	487	}
	488
	489	/* added by R. Wichmann Fri Mar 30 08:16:14 CEST 2001
	490	* RETURN TRUE only if ALL group members are trusted
	491	*/
	492	/* not static to circumvent stupid gcc 4 bug */
	493	int onlytrustedingrp(gid_t grp, uid_t *ulist)
	494	{
[137]	495	struct passwd w; / info about group member */
[1]	496	register uid_t u; / points to current ulist member */
	497	register char *p; / points to current group member */
[137]	498	struct group g; / pointer to group information */
[1]	499	register int flag = -1; /* group member found */
	500
[131]	501	#if defined(HAVE_PTHREAD) && defined (_POSIX_THREAD_SAFE_FUNCTIONS) && defined(HAVE_GETGRGID_R)
	502	struct group gr;
	503	char buffer[SH_GRBUF_SIZE];
[137]	504	struct passwd pw;
[131]	505	char pbuffer[SH_PWBUF_SIZE];
	506	#endif
	507
[134]	508	int retval = SL_FALSE;
	509
[1]	510	SL_ENTER(_("onlytrustedingrp"));
	511
	512	#ifdef TRUST_DEBUG
	513	fprintf(stderr, "trustfile: group writeable, group_gid: %ld\n",
	514	(UID_CAST)grp);
	515	#endif
	516
[131]	517	#if defined(HAVE_PTHREAD) && defined (_POSIX_THREAD_SAFE_FUNCTIONS) && defined(HAVE_GETGRGID_R)
	518	sh_getgrgid_r(grp, &gr, buffer, sizeof(buffer), &g);
	519	#else
	520	g = sh_getgrgid(grp);
	521	#endif
	522
	523	if (g == NULL)
[1]	524	{
	525	#ifdef TRUST_DEBUG
	526	fprintf(stderr,
	527	"trustfile: group_gid: %ld, no such group --> ERROR\n",
	528	(UID_CAST)grp);
	529	#endif
	530	SL_IRETURN(SL_FALSE, _("onlytrustedingrp") );
	531	}
	532
	533	/* empty group -> no problem
	534
	535	if(g->gr_mem == NULL \|\| g->gr_mem[0] == NULL )
	536	SL_IRETURN(SL_TRUE, _("onlytrustedingrp") );
	537	*/
	538
	539	/* check for untrusted members of the group
	540	*/
	541	for(p = g->gr_mem; *p != NULL; p++)
	542	{
	543	flag = -1;
	544	#ifdef TRUST_DEBUG
	545	fprintf(stderr, "trustfile: group_member: %s\n", *p);
	546	#endif
	547	/* map user name to UID and compare
	548	*/
[131]	549	#if defined(HAVE_PTHREAD) && defined (_POSIX_THREAD_SAFE_FUNCTIONS) && defined(HAVE_GETPWNAM_R)
	550	sh_getpwnam_r(*p, &pw, pbuffer, sizeof(pbuffer), &w);
	551	#else
[1]	552	w = sh_getpwnam(*p);
	553	#endif
[131]	554
[1]	555	if (w == NULL) /* not a valid user, ignore */
	556	{
	557	flag = 0;
	558	}
	559	else /* check list of trusted users */
	560	{
	561	#ifdef TRUST_DEBUG
	562	fprintf (stderr,
	563	"trustfile: uid=%ld, checking whether it is trusted\n",
	564	(UID_CAST)(w->pw_uid));
	565	#endif
	566	for(u = ulist; *u != tf_uid_neg; u++)
	567	{
	568	if (*u == (w->pw_uid) )
	569	{
	570	#ifdef TRUST_DEBUG
	571	fprintf (stderr,
	572	"trustfile: uid=%ld, trusted_uid=%ld, match found --> OK\n",
	573	(UID_CAST)(w->pw_uid), (UID_CAST)*u);
	574	#endif
	575	flag = 0;
	576	break;
	577	}
	578	else
	579	{
	580	#ifdef TRUST_DEBUG
	581	fprintf (stderr,
	582	"trustfile: uid=%ld, trusted_uid=%ld, no match\n",
	583	(UID_CAST)(w->pw_uid), (UID_CAST)*u);
	584	#endif
	585	;
	586	}
	587	}
	588	}
	589	/* not found
	590	*/
	591	if (flag == -1)
	592	{
	593	#ifdef TRUST_DEBUG
	594	fprintf (stderr,
	595	"trustfile: user=%s (gid %ld), not a trusted user --> ERROR\n", *p, (UID_CAST)grp);
	596	#endif
	597	tf_baduid = w->pw_uid;
	598	SL_IRETURN(SL_FALSE, _("onlytrustedingrp"));
	599	}
	600	}
	601
	602	#ifndef TEST_ONLY
	603	#ifdef HAVE_GETPWENT
	604	/* now check ALL users for their GID !!!
	605	*/
[134]	606	SH_MUTEX_LOCK(mutex_pwent);
	607
[1]	608	while (NULL != (w = sh_getpwent()))
	609	{
	610	if (grp == (gid_t)(w->pw_gid))
	611	{
	612	#ifdef TRUST_DEBUG
	613	fprintf(stderr, "trustfile: checking group member %s, uid %ld\n",
	614	w->pw_name, (UID_CAST)w->pw_uid);
	615	#endif
	616	/* is it a trusted user ?
	617	*/
	618	flag = -1;
	619	for(u = ulist; *u != tf_uid_neg; u++)
	620	{
	621	if (*u == (uid_t)(w->pw_uid))
	622	{
	623	#ifdef TRUST_DEBUG
	624	fprintf (stderr,
	625	"trustfile: uid=%ld, trusted_uid=%ld, match found --> OK\n",
	626	(UID_CAST)(w->pw_uid), *u);
	627	#endif
	628	flag = 0;
	629	break;
	630	}
	631	else
	632	{
	633	#ifdef TRUST_DEBUG
	634	fprintf (stderr,
	635	"trustfile: uid=%ld, trusted_uid=%ld, no match\n",
	636	(UID_CAST)(w->pw_uid), (UID_CAST)*u);
	637	#endif
	638	;
	639	}
	640	}
	641	/* not found */
	642	if (flag == -1)
	643	{
	644	#ifdef TRUST_DEBUG
	645	fprintf(stderr,"trustfile: group member %s not found in trusted users --> ERROR\n", w->pw_name);
	646	#endif
	647	tf_baduid = w->pw_uid;
[134]	648	retval = SL_FALSE;
	649	goto out;
	650	/* SL_IRETURN(SL_FALSE, _("onlytrustedingrp")); */
[1]	651	}
	652	}
	653	}
[134]	654	retval = SL_TRUE;
[1]	655
[134]	656	out:
	657
[1]	658	#ifdef HAVE_ENDPWENT
	659	sh_endpwent();
	660	#endif
[134]	661
	662	SH_MUTEX_UNLOCK(mutex_pwent);
	663
[1]	664	/* TEST_ONLY */
	665	#endif
	666	/* #ifdef HAVE_GETPWENT */
	667	#endif
	668
	669	#ifdef TRUST_DEBUG
[134]	670	if (retval == SL_TRUE)
	671	fprintf(stderr,
	672	"trustfile: group %ld: all members are trusted users --> OK\n",
	673	(UID_CAST)grp);
[1]	674	#endif
	675	/* all found
	676	*/
[134]	677	SL_IRETURN(retval, _("onlytrustedingrp"));
[1]	678	}
	679
[183]	680	int sl_trustfile(const char fname, uid_t okusers, uid_t *badusers)
[1]	681	{
	682	char fexp[MAXFILENAME]; /* file name fully expanded */
	683	register char p = fexp; / used to hold name to be checked */
	684	struct stat stbuf; /* used to check file permissions */
	685	char c; /* used to hold temp char */
	686
	687	SL_ENTER(_("sl_trustfile"));
	688	if (fname == NULL)
	689	SL_IRETURN(SL_EBADFILE, _("sl_trustfile"));
	690
	691	/*
	692	* next expand to the full file name
	693	* getfname sets sl_errno as appropriate
	694	*/
	695	#ifdef TRUST_MAIN
	696	sl_errno = getfname(fname, fexp, MAXFILENAME);
	697	if (sl_errno != 0)
	698	return sl_errno;
	699	#else
	700	if (SL_ISERROR(getfname(fname, fexp, MAXFILENAME)))
	701	SL_IRETURN(sl_errno, _("sl_trustfile"));
	702	#endif
	703
	704	if (okusers == NULL && badusers == NULL)
	705	{
	706	okusers = rootonly;
	707	rootonly[EUIDSLOT] = tf_euid;
	708	}
	709
	710	/*
	711	* now loop through the path a component at a time
	712	* note we have to special-case root
	713	*/
	714	while(*p)
	715	{
	716	/*
	717	* get next component
	718	*/
	719	while(p && p != '/')
	720	p++;
	721
	722	/* save where you are
	723	*/
	724	if (p == fexp)
	725	{
	726	/* keep the / if it's the root dir
	727	*/
	728	c = p[1];
	729	p[1] = '\0';
	730	}
	731	else
	732	{
	733	/* clobber the / if it isn't the root dir
	734	*/
	735	c = *p;
	736	*p = '\0';
	737	}
	738
	739	/*
	740	* now get the information
	741	*/
	742	if (retry_lstat(FIL__, __LINE__, fexp, &stbuf) < 0)
	743	{
[76]	744	(void) strncpy(tf_path, fexp, sizeof(tf_path));
	745	tf_path[sizeof(tf_path)-1] = '\0';
[1]	746	#ifdef TRUST_MAIN
	747	fprintf(stderr, "---------------------------------------------\n");
[76]	748	fprintf(stderr, "trustfile: ESTAT: stat(%s) failed,\n", fexp);
	749	fprintf(stderr, "maybe the file does not exist\n");
[1]	750	fprintf(stderr, "---------------------------------------------\n");
	751	#endif
	752	SL_IRETURN(SL_ESTAT, _("sl_trustfile"));
	753	}
	754
	755	#ifdef S_IFLNK
	756	/*
	757	* if it's a symbolic link, recurse
	758	*/
	759	if ((stbuf.st_mode & S_IFLNK) == S_IFLNK)
	760	{
	761	/*
	762	* this is tricky
	763	* if the symlink is to an absolute path
	764	* name, just call trustfile on it; but
	765	* if it's a relative path name, it's
	766	* interpreted WRT the current working
	767	* directory AND NOT THE FILE NAME!!!!!
	768	* so, we simply put /../ at the end of
	769	* the file name, then append the symlink
	770	* contents; trustfile will canonicalize
	771	* this, and the /../ we added "undoes"
	772	* the name of the symlink to put us in
	773	* the current working directory, at
	774	* which point the symlink contents (appended
	775	* to the CWD) are interpreted correctly.
	776	* got it?
	777	*/
	778	char csym[MAXFILENAME]; /* contents of symlink file */
	779	char full[MAXFILENAME]; /* "full" name of symlink */
	780	register char b, t; /* used to copy stuff around */
	781	register int lsym; /* num chars in symlink ref */
	782	register int i; /* trustworthy or not? */
[170]	783	const char * t_const;
[171]	784	char *end;
[1]	785
	786	/*
	787	* get what the symbolic link points to
	788	*
	789	* The original code does not check the return code of readlink(),
	790	* and has an off-by-one error
	791	* (MAXFILENAME instead of MAXFILENAME-1)
	792	* R.W. Tue May 29 22:05:16 CEST 2001
	793	*/
	794	lsym = readlink(fexp, csym, MAXFILENAME-1);
	795	if (lsym >= 0)
	796	csym[lsym] = '\0';
	797	else
	798	{
	799	#ifdef TRUST_MAIN
	800	fprintf(stderr, "---------------------------------------------\n");
	801	fprintf(stderr, "trustfile: EBADNAME: readlink(%s) failed\n",
	802	fexp);
	803	fprintf(stderr, "---------------------------------------------\n");
	804	#endif
	805	SL_IRETURN(SL_EBADNAME, _("sl_trustfile"));
	806	}
	807
	808	/*
	809	* relative or absolute referent?
	810	*/
	811	if (csym[0] != '/')
	812	{
[171]	813	/* pointer to one above last element
	814	*/
	815	end = &full[MAXFILENAME-1]; ++end;
	816
[1]	817	/* initialize pointers
	818	*/
	819	b = full;
	820
	821	/* copy in base path
	822	*/
	823	t = fexp;
[171]	824	while(*t && b < end)
[1]	825	b++ = t++;
	826
	827	/* smack on the /../
	828	*/
[170]	829	t_const = "/../";
[171]	830	while(*t && b < end)
[170]	831	b++ = t_const++;
[1]	832
	833	/* append the symlink referent
	834	*/
	835	t = csym;
[171]	836	while(*t && b < end)
[1]	837	b++ = t++;
	838
	839	/* see if we're too big
	840	*/
[171]	841	if (*t \|\| b == end)
[1]	842	{
	843	/* yes -- error
	844	*/
[76]	845	(void) strncpy(tf_path, fexp, sizeof(tf_path));
	846	tf_path[sizeof(tf_path)-1] = '\0';
[1]	847	#ifdef TRUST_MAIN
	848	fprintf(stderr, "---------------------------------------------\n");
	849	fprintf(stderr,
	850	"trustfile: ETRUNC: normalized path too long (%s)\n",
	851	fexp);
	852	fprintf(stderr, "---------------------------------------------\n");
	853	#endif
	854	SL_IRETURN(SL_ETRUNC, _("sl_trustfile"));
	855	}
	856	*b = '\0';
	857	}
	858	else
	859	{
	860	/* absolute -- just copy */
	861	/* overflow can't occur as the arrays */
	862	/* are the same size */
	863	(void) strcpy(full, csym); /* known to fit */
	864	}
	865	/*
	866	* now check out this file and its ancestors
	867	*/
	868	if ((i = sl_trustfile(full, okusers, badusers)) != SL_ENONE)
	869	SL_IRETURN(i, _("sl_trustfile"));
	870
	871	/*
	872	* okay, this part is valid ... let's check the rest
	873	* put the / back
	874	*/
	875	if (p == fexp)
	876	{
	877	/* special case for root */
	878	p[1] = c;
	879	p++;
	880	}
	881	else
	882	{
	883	/* ordinary case for everything else */
	884	*p = c;
	885	if (*p)
	886	p++;
	887	}
	888	continue;
	889	}
	890	#endif
	891
	892
	893	#ifdef TRUST_DEBUG
	894	fprintf(stderr, "\ntrustfile: checking path=%s\n", fexp);
	895	#endif
	896	/*
	897	* if the owner is not trusted then -- as the owner can
	898	* change protection modes -- he/she can write to the
	899	* file regardless of permissions, so bomb
	900	*/
	901	if (((okusers != NULL && SL_FALSE == isin((uid_t)stbuf.st_uid,okusers))\|\|
	902	(badusers != NULL && SL_TRUE == isin((uid_t)stbuf.st_uid,badusers))))
	903	{
	904	#ifdef TRUST_DEBUG
	905	fprintf(stderr, "---------------------------------------------\n");
	906	fprintf(stderr, "trustfile: EBADUID %s (owner not trusted)\n",
	907	fexp);
	908	fprintf(stderr, "The owner of this file/directory is not in samhains\n");
	909	fprintf(stderr, "list of trusted users.\n");
	910	fprintf(stderr, "Please run ./configure again with the option\n");
	911	fprintf(stderr, " ./configure [more options] --with-trusted=0,...,UID\n");
	912	fprintf(stderr, "where UID is the UID of the (yet) untrusted user.\n");
	913	fprintf(stderr, "---------------------------------------------\n");
	914	#endif
[76]	915	(void) strncpy(tf_path, fexp, sizeof(tf_path));
	916	tf_path[sizeof(tf_path)-1] = '\0';
	917
[1]	918	tf_baduid = (uid_t) stbuf.st_uid;
	919	SL_IRETURN(SL_EBADUID, _("sl_trustfile"));
	920	}
	921
	922	/*
	923	* if a group member can write but the
	924	* member is not trusted, bomb; but if
	925	* sticky bit semantics are honored, it's
	926	* okay
	927	*/
	928	/* Thu Mar 29 21:10:28 CEST 2001 Rainer Wichmann
	929	* replace !isingrp() with onlytrustedingrp(), as isingrp()
	930	* will return at the first trusted user, even if there are additional
	931	* (untrusted) users in the group
	932	*/
	933	if (((stbuf.st_mode & S_IWGRP) == S_IWGRP) &&
	934	((okusers != NULL && !onlytrustedingrp((gid_t)stbuf.st_gid,okusers))\|\|
	935	(badusers != NULL && isingrp((gid_t)stbuf.st_gid, badusers)))
	936	#ifdef STICKY
	937	&& ((stbuf.st_mode&S_IFDIR) != S_IFDIR \|\|
	938	(stbuf.st_mode&S_ISVTX) != S_ISVTX)
	939	#endif
	940	)
	941	{
	942	#ifdef TRUST_DEBUG
	943	fprintf(stderr, "---------------------------------------------\n");
	944	fprintf(stderr,
	945	"trustfile: EBADGID %ld %s (group member not trusted)\n",
	946	(UID_CAST)stbuf.st_gid, fexp);
	947	fprintf(stderr, "This file/directory is group writeable, and one of the group members\n");
	948	fprintf(stderr, "is not in samhains list of trusted users.\n");
	949	fprintf(stderr, "Please run ./configure again with the option\n");
	950	fprintf(stderr, " ./configure [more options] --with-trusted=0,...,UID\n");
	951	fprintf(stderr, "where UID is the UID of the (yet) untrusted user.\n");
	952	fprintf(stderr, "---------------------------------------------\n");
	953	#endif
[76]	954	(void) strncpy(tf_path, fexp, sizeof(tf_path));
	955	tf_path[sizeof(tf_path)-1] = '\0';
	956
[1]	957	tf_badgid = (gid_t) stbuf.st_gid;
	958	SL_IRETURN(SL_EBADGID, _("sl_trustfile"));
	959	}
	960	/*
	961	* if other can write, bomb; but if the sticky
	962	* bit semantics are honored, it's okay
	963	*/
	964	if (((stbuf.st_mode & S_IWOTH) == S_IWOTH)
	965	#ifdef STICKY
	966	&& ((stbuf.st_mode&S_IFDIR) != S_IFDIR \|\|
	967	(stbuf.st_mode&S_ISVTX) != S_ISVTX)
	968	#endif
	969	)
	970	{
	971	#ifdef TRUST_DEBUG
	972	fprintf(stderr, "---------------------------------------------\n");
	973	fprintf(stderr, "trustfile: EBADOTH (world writeable): %s\n",
	974	fexp);
	975	fprintf(stderr, "This file/directory is world writeable.\n");
	976	fprintf(stderr, "---------------------------------------------\n");
	977	#endif
[76]	978	(void) strncpy(tf_path, fexp, sizeof(tf_path));
	979	tf_path[sizeof(tf_path)-1] = '\0';
	980
[1]	981	SL_IRETURN(SL_EBADOTH, _("sl_trustfile"));
	982	}
	983	/*
	984	* put the / back
	985	*/
	986	if (p == fexp)
	987	{
	988	/* special case for root */
	989	p[1] = c;
	990	p++;
	991	}
	992	else
	993	{
	994	/* ordinary case for everything else */
	995	*p = c;
	996	if (*p)
	997	p++;
	998	}
	999	}
	1000	/*
	1001	* yes, it can be trusted
	1002	*/
[76]	1003	(void) strncpy(tf_path, fexp, sizeof(tf_path));
	1004	tf_path[sizeof(tf_path)-1] = '\0';
	1005
[1]	1006	SL_IRETURN(SL_ENONE, _("sl_trustfile"));
	1007	}
	1008
	1009	#ifdef TRUST_MAIN
[192]	1010
	1011	#if defined(HOST_IS_CYGWIN) \|\| defined(__cygwin__) \|\| defined(__CYGWIN32__) \|\| defined(__CYGWIN__)
	1012	int main()
	1013	{
	1014	return 0;
	1015	}
	1016	#else
[1]	1017	int main (int argc, char * argv[])
	1018	{
	1019	int status;
	1020	#if defined(SH_WITH_SERVER)
	1021	struct passwd * pass;
	1022	#endif
	1023
	1024	if (argc < 2) {
	1025	fprintf(stderr, "%s: Usage: %s <fullpath>\n", argv[0], argv[0]);
	1026	return 1;
	1027	}
	1028
	1029	tf_path[0] = '\0';
	1030	#if defined(SH_WITH_SERVER)
[131]	1031	pass = sh_getpwnam(SH_IDENT); /* TESTONLY */
[1]	1032	if (pass != NULL)
	1033	tf_euid = pass->pw_uid;
	1034	else
	1035	{
	1036	fprintf(stderr, "trustfile: ERROR: getpwnam(%s) failed\n",
	1037	SH_IDENT);
	1038	return 1;
	1039	}
	1040	#else
	1041	tf_euid = geteuid();
	1042	#endif
	1043
	1044	status = sl_trustfile(argv[1], NULL, NULL);
	1045	if (status != SL_ENONE)
	1046	{
	1047	fprintf(stderr, "trustfile: ERROR: not a trusted path: %s\n",
	1048	argv[1]);
	1049	return 1;
	1050	}
	1051	return 0;
	1052	}
	1053	#endif
[192]	1054	#endif
[1]	1055
	1056
	1057

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