1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 #include "packer.h"
27
28 /*
29 * This file steers the creation of the Crack Dictionary Database.
30 * Based on a list of source dictionaries specified by the administrator,
31 * we create the Database by sorting each dictionary (in memory, one at
32 * a time), writing the sorted result to a temporary file, and merging
33 * all the temporary files into the Database.
34 *
35 * The current implementation has a number of limitations
36 * - each single source dictionary has to fit in memory
37 * - each single source dictionary has to be smaller than 2GByte
38 * - each single source dictionary can only hold up to 4GB words
39 * None of these seem real, practical, problems to me.
40 *
41 * All of this is meant to be run by one thread per host. The caller is
42 * responsible for locking things appropriately (as make_dict_database
43 * in dict.c does).
44 */
45
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <unistd.h>
49 #include <ctype.h>
50 #include <string.h>
51 #include <errno.h>
52 #include <sys/stat.h>
53 #include <fcntl.h>
54
55 /* Stuff used for sorting the dictionary */
56 static char *buf; /* used to hold the source dictionary */
57 static uint_t *offsets; /* array of word-offsets into "buf" */
58 static uint_t off_idx = 0; /* first free index in offsets array */
59 static size_t off_size = 0; /* offsets array size */
60
61 /* stuff to keep track of the temporary files */
62 #define FNAME_TEMPLATE "/var/tmp/authtok_check.XXXXXX"
63 #define MAXTMP 64
64 static FILE *tmpfp[MAXTMP]; /* FILE *'s to (unlinked) temporary files */
65 static int tmpfp_idx = 0; /* points to first free entry in tmpfp */
66
67 #define MODNAME "pam_authtok_check::packer"
68
69 /*
70 * int writeout(void)
71 *
72 * Write the sorted wordlist to disk. We create a temporary file
73 * (in /var/tmp), and immediately unlink() it. We keep an open
74 * FILE pointer to it in tmpfp[] for later use.
75 *
76 * returns 0 on success, -1 on failure (can't create file/output failure).
77 */
78 int
writeout(void)79 writeout(void)
80 {
81 int i = 0;
82 char tmpname[sizeof (FNAME_TEMPLATE)];
83 int fd;
84
85 if (tmpfp_idx == MAXTMP) {
86 syslog(LOG_ERR, MODNAME ": too many temporary "
87 "files (maximum %d exceeded)", MAXTMP);
88 return (-1);
89 }
90
91 (void) strcpy(tmpname, FNAME_TEMPLATE);
92 if ((fd = mkstemp(tmpname)) == -1) {
93 syslog(LOG_ERR, MODNAME ": mkstemp() failed: %s\n",
94 strerror(errno));
95 return (-1);
96 }
97 (void) unlink(tmpname);
98
99 if ((tmpfp[tmpfp_idx] = fdopen(fd, "w+F")) == NULL) {
100 syslog(LOG_ERR, MODNAME ": fdopen failed: %s",
101 strerror(errno));
102 (void) close(fd);
103 return (-1);
104 }
105
106 /* write words to file */
107 while (i < off_idx) {
108 if (fprintf(tmpfp[tmpfp_idx], "%s\n", &buf[offsets[i++]]) < 0) {
109 syslog(LOG_ERR, MODNAME ": write to file failed: %s",
110 strerror(errno));
111 (void) close(fd);
112 return (-1);
113 }
114 }
115
116 /* we have one extra tmpfp */
117 tmpfp_idx++;
118
119 return (0);
120 }
121
122 /*
123 * int insert_word(int off)
124 *
125 * insert an offset into the offsets-array. If the offsets-array is out of
126 * space, we allocate additional space (in CHUNKs)
127 *
128 * returns 0 on success, -1 on failure (out of memory)
129 */
130 int
insert_word(int off)131 insert_word(int off)
132 {
133 #define CHUNK 10000
134
135 if (off_idx == off_size) {
136 uint_t *tmp;
137 off_size += CHUNK;
138 tmp = realloc(offsets, sizeof (uint_t) * off_size);
139 if (tmp == NULL) {
140 syslog(LOG_ERR, MODNAME ": out of memory");
141 free(offsets);
142 off_idx = off_size = 0;
143 offsets = NULL;
144 return (-1);
145 }
146 offsets = tmp;
147 }
148
149 offsets[off_idx++] = off;
150 return (0);
151 }
152
153 /*
154 * translate(buf, size)
155 *
156 * perform "tr '[A-Z]' '[a-z]' | tr -cd '\012[a-z][0-9]'" on the
157 * words in "buf" and insert each of them into the offsets-array.
158 * We refrain from using 'isupper' and 'islower' to keep this strictly
159 * ASCII-only, as is the original Cracklib code.
160 *
161 * returns 0 on success, -1 on failure (failure of insert_word)
162 */
163 int
translate(char * buf,size_t size)164 translate(char *buf, size_t size)
165 {
166 char *p, *q, *e;
167 char c;
168 int wordstart;
169
170 e = &buf[size];
171
172 wordstart = 0;
173 for (p = buf, q = buf; q < e; q++) {
174 c = *q;
175 if (c >= 'A' && c <= 'Z') {
176 *(p++) = tolower(c);
177 } else if (c == '\n') {
178 *(p++) = '\0';
179 /*
180 * make sure we only insert words consisting of
181 * MAXWORDLEN-1 bytes or less
182 */
183 if (p-&buf[wordstart] > MAXWORDLEN)
184 buf[wordstart+MAXWORDLEN-1] = '\0';
185 if (insert_word(wordstart) != 0)
186 return (-1);
187 wordstart = p-buf;
188 } else if ((c >= 'a' && c <= 'z') || (c >= '0' && c <= '9')) {
189 *(p++) = c;
190 }
191 }
192 return (0);
193 }
194
195 /*
196 * int compare(a, b)
197 *
198 * helper-routine used for quicksort. we compate two words in the
199 * buffer, one start starts at index "a", and the other one that starts
200 * at index "b"
201 */
202 int
compare(const void * a,const void * b)203 compare(const void *a, const void *b)
204 {
205 int idx_a = *(uint_t *)a, idx_b = *(uint_t *)b;
206
207 return (strcmp(&buf[idx_a], &buf[idx_b]));
208 }
209
210 /*
211 *
212 * int sort_file(fname)
213 *
214 * We sort the file in memory: we read the dictionary file, translate all
215 * newlines to '\0's, all uppercase ASCII characters to lowercase characters
216 * and removing all characters but '[a-z][0-9]'.
217 * We maintain an array of offsets into the buffer where each word starts
218 * and sort this array using qsort().
219 *
220 * This implements the original cracklib code that did an execl of
221 * sh -c "/usr/bin/cat <list of files> |
222 * /usr/bin/tr '[A-Z]' '[a-z]' | /usr/bin/tr -cd '\012[a-z][0-9]' |
223 * sort -o tmfpfile
224 *
225 * returns 0 on success, -1 on failure.
226 */
227 int
sort_file(char * fname)228 sort_file(char *fname)
229 {
230 int fd;
231 struct stat statbuf;
232 ssize_t n;
233 int ret = -1;
234
235 if ((fd = open(fname, O_RDONLY)) == -1) {
236 syslog(LOG_ERR, MODNAME ": failed to open %s: %s",
237 fname, strerror(errno));
238 return (-1);
239 }
240
241 if (fstat(fd, &statbuf) == -1) {
242 syslog(LOG_ERR, MODNAME ": fstat() failed (%s)",
243 strerror(errno));
244 (void) close(fd);
245 return (-1);
246 }
247 if ((buf = malloc(statbuf.st_size + 1)) == NULL) {
248 syslog(LOG_ERR, MODNAME ": out of memory");
249 goto error;
250 }
251
252 n = read(fd, buf, statbuf.st_size);
253
254 if (n == -1) {
255 if (errno == EINVAL)
256 syslog(LOG_ERR, MODNAME ": %s is too big. "
257 "Split the file into smaller files.", fname);
258 else
259 syslog(LOG_ERR, MODNAME ": read failed: %s",
260 strerror(errno));
261 goto error;
262 }
263
264 if (translate(buf, n) == 0) {
265 qsort((void *)offsets, off_idx, sizeof (int), compare);
266
267 if (writeout() == 0)
268 ret = 0;
269 }
270
271 error:
272 (void) close(fd);
273
274 if (buf != NULL)
275 free(buf);
276 if (offsets != NULL)
277 free(offsets);
278 offsets = NULL;
279 off_size = 0;
280 off_idx = 0;
281 return (ret);
282 }
283
284 /*
285 * We merge the temporary files created by previous calls to sort_file()
286 * and insert the thus sorted words into the cracklib database
287 *
288 * returns 0 on success, -1 on failure.
289 */
290 int
merge_files(PWDICT * pwp)291 merge_files(PWDICT *pwp)
292 {
293 int ti;
294 char *words[MAXTMP];
295 char lastword[MAXWORDLEN];
296 int choice;
297
298 lastword[0] = '\0';
299
300 for (ti = 0; ti < tmpfp_idx; ti++)
301 if ((words[ti] = malloc(MAXWORDLEN)) == NULL) {
302 while (--ti >= 0)
303 free(words[ti]);
304 return (-1);
305 }
306
307 /*
308 * we read the first word of each of the temp-files into words[].
309 */
310 for (ti = 0; ti < tmpfp_idx; ti++) {
311 (void) fseek(tmpfp[ti], 0, SEEK_SET);
312 (void) fgets(words[ti], MAXWORDLEN, tmpfp[ti]);
313 words[ti][MAXWORDLEN-1] = '\0';
314 }
315
316 /*
317 * next, we emit the word that comes first (lexicographically),
318 * and replace that word with a new word from the file it
319 * came from. If the file is exhausted, we close the fp and
320 * swap the fp with the last fp in tmpfp[].
321 * we then decrease tmpfp_idx and continue with what's left until
322 * we run out of open FILE pointers.
323 */
324 while (tmpfp_idx != 0) {
325 choice = 0;
326
327 for (ti = 1; ti < tmpfp_idx; ti++)
328 if (strcmp(words[choice], words[ti]) > 0)
329 choice = ti;
330 /* Insert word in Cracklib database */
331 (void) Chomp(words[choice]);
332 if (words[choice][0] != '\0' &&
333 strcmp(lastword, words[choice]) != 0) {
334 (void) PutPW(pwp, words[choice]);
335 (void) strncpy(lastword, words[choice], MAXWORDLEN);
336 }
337
338 if (fgets(words[choice], MAXWORDLEN, tmpfp[choice]) == NULL) {
339 (void) fclose(tmpfp[choice]);
340 tmpfp[choice] = tmpfp[tmpfp_idx - 1];
341 tmpfp_idx--;
342 } else
343 words[choice][MAXWORDLEN-1] = '\0';
344 }
345 return (0);
346 }
347
348 /*
349 * int packer(list)
350 *
351 * sort all dictionaries in "list", and feed the words into the Crack
352 * Password Database.
353 *
354 * returns 0 on sucess, -1 on failure.
355 */
356 int
packer(char * list,char * path)357 packer(char *list, char *path)
358 {
359 PWDICT *pwp;
360 char *listcopy, *fname;
361 int ret = 0;
362
363 if ((listcopy = strdup(list)) == NULL) {
364 syslog(LOG_ERR, MODNAME ": out of memory");
365 return (-1);
366 }
367
368 if (!(pwp = PWOpen(path, "wF")))
369 return (-1);
370
371 fname = strtok(listcopy, " \t,");
372 while (ret == 0 && fname != NULL) {
373 if ((ret = sort_file(fname)) == 0)
374 fname = strtok(NULL, " \t,");
375 }
376 free(listcopy);
377
378 if (ret == 0)
379 ret = merge_files(pwp);
380
381 (void) PWClose(pwp);
382
383 return (ret);
384 }
385