3 * Generate and validate cryptographic cookies
5 * (c) 1999 Mark Wooding
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of Catacomb.
12 * Catacomb is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * Catacomb is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with Catacomb; if not, write to the Free Software Foundation,
24 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 /*----- Header files ------------------------------------------------------*/
29 #define _FILE_OFFSET_BITS 64
39 #include <mLib/base64.h>
40 #include <mLib/bits.h>
41 #include <mLib/dstr.h>
42 #include <mLib/macros.h>
43 #include <mLib/mdwopt.h>
44 #include <mLib/quis.h>
45 #include <mLib/report.h>
54 /*----- Handy global state ------------------------------------------------*/
56 static const char *keyfile = "keyring";
58 /*----- Cookie format -----------------------------------------------------*/
60 /* --- Cookie header structure (unpacked) --- */
62 typedef struct cookie {
67 /* --- Size of a cookie header (packed) --- */
69 #define COOKIE_SZ (4 + 8)
71 /* --- @COOKIE_PACK@ --- *
73 * Arguments: @p@ = pointer to destination buffer
74 * @c@ = pointer to source cookie header block
76 * Use: Packs a cookie header into an octet buffer in a machine-
80 #define COOKIE_PACK(p, c) do { \
81 octet *_p = (octet *)(p); \
82 const cookie *_c = (c); \
83 STORE32(_p + 0, _c->k); \
84 STORE32(_p + 4, ((_c->exp & ~(unsigned long)MASK32) >> 16) >> 16); \
85 STORE32(_p + 8, _c->exp); \
88 /* --- @COOKIE_UNPACK@ --- *
90 * Arguments: @c@ = pointer to destination cookie header
91 * @p@ = pointer to source buffer
93 * Use: Unpacks a cookie header from an octet buffer into a
94 * machine-specific but comprehensible structure.
97 #define COOKIE_UNPACK(c, p) do { \
99 const octet *_p = (const octet *)(p); \
100 _c->k = LOAD32(_p + 0); \
101 _c->exp = ((time_t)(((LOAD32(_p + 4) << 16) << 16) & \
102 ~(unsigned long)MASK32) | \
103 (time_t)LOAD32(_p + 8)); \
106 /*----- Useful shared functions -------------------------------------------*/
108 /* --- @doopen@ --- *
110 * Arguments: @key_file *f@ = pointer to key file block
111 * @unsigned how@ = method to open file with
115 * Use: Opens a key file and handles errors by panicking
119 static void doopen(key_file *f, unsigned how)
121 if (key_open(f, keyfile, how, key_moan, 0)) {
122 die(EXIT_FAILURE, "couldn't open file `%s': %s",
123 keyfile, strerror(errno));
127 /* --- @doclose@ --- *
129 * Arguments: @key_file *f@ = pointer to key file block
133 * Use: Closes a key file and handles errors by panicking
137 static void doclose(key_file *f)
139 switch (key_close(f)) {
141 die(EXIT_FAILURE, "couldn't write file `%s': %s",
142 keyfile, strerror(errno));
144 die(EXIT_FAILURE, "keyring file `%s' broken: %s (repair manually)",
145 keyfile, strerror(errno));
149 /* --- @getmac@ --- *
151 * Arguments: @key *k@ = key to use
152 * @const char *app@ = application name
154 * Returns: The MAC to use.
156 * Use: Finds the right MAC for the given key.
159 static gmac *getmac(key *k, const char *app)
176 /* --- Pick out the right MAC --- */
179 if ((q = key_getattr(0, k, "mac")) != 0) {
182 } else if (STRNCMP(k->type, ==, app, n) && k->type[n] == '-') {
183 dstr_puts(&d, k->type);
186 die(EXIT_FAILURE, "no MAC algorithm for key `%s'", t.buf);
187 if ((cm = gmac_byname(p)) == 0) {
188 die(EXIT_FAILURE, "MAC algorithm `%s' not found in key `%s'",
192 /* --- Unlock the key --- */
196 if ((e = key_unpack(&kp, k->k, &t)) != 0) {
197 die(EXIT_FAILURE, "error unpacking key `%s': %s",
198 t.buf, key_strerror(e));
201 /* --- Make the MAC object --- */
203 if (keysz(kb.sz, cm->keysz) != kb.sz)
204 die(EXIT_FAILURE, "key %s has bad length (%lu) for MAC %s",
205 t.buf, (unsigned long)kb.sz, cm->name);
206 m = cm->key(kb.k, kb.sz);
211 /*----- Command implementation --------------------------------------------*/
213 /* --- @cmd_gen@ --- */
215 static int cmd_gen(int argc, char *argv[])
221 const char *tag = "cookie";
223 cookie c = { 0, KEXP_EXPIRE };
228 octet buf[COOKIE_SZ];
231 /* --- Various useful flag bits --- */
235 /* --- Parse options for the subcommand --- */
238 static struct option opt[] = {
239 { "bits", OPTF_ARGREQ, 0, 'b' },
240 { "expire", OPTF_ARGREQ, 0, 'e' },
241 { "key", OPTF_ARGREQ, 0, 'k' },
244 int i = mdwopt(argc, argv, "+b:e:i:t:", opt, 0, 0, 0);
248 /* --- Handle the various options --- */
252 /* --- Fetch a size in bits --- */
255 if (!(bits = atoi(optarg)) || bits % 8)
256 die(EXIT_FAILURE, "bad number of bits: `%s'", optarg);
259 /* --- Fetch an expiry time --- */
262 if (STRCMP(optarg, ==, "forever"))
263 c.exp = KEXP_FOREVER;
264 else if ((c.exp = get_date(optarg, 0)) == -1)
265 die(EXIT_FAILURE, "bad expiry date: `%s'", optarg);
268 /* --- Fetch a key type --- */
274 /* --- Other things are bogus --- */
282 /* --- Various sorts of bogosity --- */
284 if (fl & f_bogus || optind + 1 < argc)
286 "Usage: generate [-b BITS] [-e TIME] [-k TAG] [DATA]");
288 /* --- Choose a default expiry time --- */
290 if (c.exp == KEXP_EXPIRE)
291 c.exp = time(0) + 7 * 24 * 60 * 60;
293 /* --- Open the key file and get the key --- */
295 doopen(&f, KOPEN_WRITE);
296 if ((k = key_bytag(&f, tag)) == 0) {
297 die(EXIT_FAILURE, "no key with tag `%s' in keyring `%s'",
302 if ((err = key_used(&f, k, c.exp)) != 0)
303 die(EXIT_FAILURE, "can't generate cookie: %s", key_strerror(err));
304 m = getmac(k, "cookie");
305 if (bits/8 > GM_CLASS(m)->hashsz) {
306 die(EXIT_FAILURE, "inapproriate bit length for `%s' MACs",
310 /* --- Store and MAC the cookie --- */
312 COOKIE_PACK(buf, &c);
315 GH_HASH(h, buf, sizeof(buf));
317 GH_HASH(h, argv[optind], strlen(argv[optind]));
320 /* --- Encode and emit the finished cookie --- */
324 base64_encode(&b, buf, sizeof(buf), &d);
325 base64_encode(&b, t, bits/8, &d);
326 base64_encode(&b, 0, 0, &d);
339 /* --- @cmd_verify@ --- */
341 static int cmd_verify(int argc, char *argv[])
346 int bits = -1, minbits = 32;
355 time_t now = time(0);
357 /* --- Various useful flag bits --- */
363 /* --- Parse options for the subcommand --- */
366 static struct option opt[] = {
367 { "bits", OPTF_ARGREQ, 0, 'b' },
368 { "min-bits", OPTF_ARGREQ, 0, 'm' },
369 { "forever", 0, 0, 'f' },
370 { "quiet", 0, 0, 'q' },
371 { "verbose", 0, 0, 'v' },
372 { "utc", 0, 0, 'u' },
375 int i = mdwopt(argc, argv, "+b:m:fqvu", opt, 0, 0, 0);
379 /* --- Handle the various options --- */
383 /* --- Fetch a size in bits --- */
386 if (!(bits = atoi(optarg)) || bits % 8)
387 die(EXIT_FAILURE, "bad number of bits: `%s'", optarg);
390 if (!(minbits = atoi(optarg)) || minbits % 8)
391 die(EXIT_FAILURE, "bad number of bits: `%s'", optarg);
394 /* --- Miscellaneous flags --- */
409 /* --- Other things are bogus --- */
417 /* --- Various sorts of bogosity --- */
419 if (fl & f_bogus || optind == argc || optind + 2 < argc) {
421 "Usage: verify [-fuqv] [-b BITS] [-m BITS] COOKIE [DATA]");
423 doopen(&f, KOPEN_READ);
425 /* --- Decode the base64 wrapping --- */
428 base64_decode(&b, argv[optind], strlen(argv[optind]), &d);
429 base64_decode(&b, 0, 0, &d);
431 if (d.len < COOKIE_SZ + 1) {
432 if (v) printf("FAIL cookie too small\n");
436 /* --- Extract the relevant details --- */
438 COOKIE_UNPACK(&c, d.buf);
442 if (c.exp == KEXP_FOREVER)
443 strcpy(buf, "forever");
450 fmt = "%Y-%m-%d %H:%M:%S UTC";
452 tm = localtime(&c.exp);
453 fmt = "%Y-%m-%d %H:%M:%S %Z";
455 strftime(buf, sizeof(buf), fmt, tm);
457 printf("INFO keyid = %08lx; expiry = %s\n", (unsigned long)c.k, buf);
460 /* --- Check the authentication token width --- */
462 cbits = (d.len - COOKIE_SZ) * 8;
463 if (v > 2) printf("INFO authentication token width = %i bits\n", cbits);
465 if (cbits < minbits) {
466 if (v) printf("FAIL authentication token too narrow\n");
471 if (v) printf("FAIL authentication token width doesn't match\n");
475 /* --- Get the key --- */
477 if ((k = key_byid(&f, c.k)) == 0) {
478 if (v) printf("FAIL keyid %08lx unavailable\n", (unsigned long)c.k);
482 /* --- Check that the cookie authenticates OK --- */
484 m = getmac(k, "cookie");
486 GH_HASH(h, d.buf, COOKIE_SZ);
487 if (argv[optind + 1])
488 GH_HASH(h, argv[optind + 1], strlen(argv[optind + 1]));
491 if (!ct_memeq(t, d.buf + COOKIE_SZ, cbits / 8)) {
492 if (v) printf("FAIL bad authentication token\n");
496 /* --- See whether the cookie has expired --- */
498 if (c.exp == KEXP_FOREVER) {
499 if (!(fl & f_forever)) {
500 if (v) printf("FAIL forever cookies not allowed\n");
503 if (k->exp != KEXP_FOREVER) {
504 if (v) printf("FAIL cookie lasts forever but key will expire\n");
507 } else if (c.exp < now) {
508 if (v) printf("FAIL cookie has expired\n");
512 if (v) printf("OK\n");
529 /*----- Main command table ------------------------------------------------*/
531 static int cmd_help(int, char **);
535 listtab[i].name, listtab[i].name) \
536 LI("Message authentication algorithms", mac, \
537 gmactab[i], gmactab[i]->name)
539 MAKELISTTAB(listtab, LISTS)
541 static int cmd_show(int argc, char *argv[])
543 return (displaylists(listtab, argv + 1));
546 static cmd cmds[] = {
547 { "help", cmd_help, "help [COMMAND...]" },
548 { "show", cmd_show, "show [ITEM...]" },
549 { "generate", cmd_gen,
550 "generate [-b BITS] [-e TIME] [-k TAG] [DATA]", "\
553 -b, --bits=N Use an N-bit token in the cookie.\n\
554 -e, --expire=TIME Make the cookie expire after TIME.\n\
555 -k, --key=TAG Use key TAG to create the token.\n\
557 { "verify", cmd_verify,
558 "verify [-fuqv] [-b BITS] [-m BITS] COOKIE [DATA]", "\
561 -b, --bits=N Accept tokens exactly N bits long only.\n\
562 -m, --min-bits=N Accept tokens N bits long or more.\n\
563 -f, --forever Accept cookies which never expire.\n\
564 -u, --utc Output cookie expiry dates in UTC.\n\
565 -q, --quiet Produce less output while checking cookies.\n\
566 -v, --verbose Produce more output while checking cookies.\n\
571 static int cmd_help(int argc, char *argv[])
573 sc_help(cmds, stdout, argv + 1);
577 /*----- Main code ---------------------------------------------------------*/
579 /* --- Helpful GNUy functions --- */
581 static void usage(FILE *fp)
583 fprintf(fp, "Usage: %s [-k KEYRING] COMMAND [ARGS]\n", QUIS);
586 void version(FILE *fp)
588 fprintf(fp, "%s, Catacomb version " VERSION "\n", QUIS);
591 void help_global(FILE *fp)
595 Generates and validates cryptographic cookies. Command line options\n\
598 -h, --help [COMMAND] Display this help text (or help for COMMAND).\n\
599 -v, --version Display version number.\n\
600 -u, --usage Display short usage summary.\n\
602 -k, --key-file=FILE Read and write keys in FILE.\n",
608 * Arguments: @int argc@ = number of command line arguments
609 * @char *argv[]@ = array of arguments
611 * Returns: Zero if OK, nonzero if not.
613 * Use: Generates and validates cryptographic cookies.
616 int main(int argc, char *argv[])
623 /* --- Initialize the library --- */
628 /* --- Options parsing --- */
631 static struct option opt[] = {
633 /* --- Standard GNUy help options --- */
635 { "help", 0, 0, 'h' },
636 { "version", 0, 0, 'v' },
637 { "usage", 0, 0, 'u' },
639 /* --- Actual relevant options --- */
641 { "keyring", OPTF_ARGREQ, 0, 'k' },
643 /* --- Magic terminator --- */
647 int i = mdwopt(argc, argv, "+hvu k:", opt, 0, 0, 0);
653 /* --- Helpful GNUs --- */
662 sc_help(cmds, stdout, argv + optind);
665 /* --- Real genuine useful options --- */
671 /* --- Bogus things --- */
679 if ((f & f_bogus) || optind == argc) {
684 /* --- Dispatch to appropriate command handler --- */
689 return (findcmd(cmds, argv[0])->cmd(argc, argv));
695 /*----- That's all, folks -------------------------------------------------*/