5 * Generate and validate cryptographic cookies
7 * (c) 1999 Mark Wooding
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Catacomb.
14 * Catacomb is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * Catacomb is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with Catacomb; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
29 /*----- Header files ------------------------------------------------------*/
39 #include <mLib/base64.h>
40 #include <mLib/bits.h>
41 #include <mLib/dstr.h>
42 #include <mLib/mdwopt.h>
43 #include <mLib/quis.h>
44 #include <mLib/report.h>
52 /*----- Handy global state ------------------------------------------------*/
54 static const char *keyfile
= "keyring";
56 /*----- Cookie format -----------------------------------------------------*/
58 /* --- Cookie header structure (unpacked) --- */
60 typedef struct cookie
{
65 /* --- Size of a cookie header (packed) --- */
67 #define COOKIE_SZ (4 + 8)
69 /* --- @COOKIE_PACK@ --- *
71 * Arguments: @p@ = pointer to destination buffer
72 * @c@ = pointer to source cookie header block
74 * Use: Packs a cookie header into an octet buffer in a machine-
78 #define COOKIE_PACK(p, c) do { \
79 octet *_p = (octet *)(p); \
80 const cookie *_c = (c); \
81 STORE32(_p + 0, _c->k); \
82 STORE32(_p + 4, ((_c->exp & ~MASK32) >> 16) >> 16); \
83 STORE32(_p + 8, _c->exp); \
86 /* --- @COOKIE_UNPACK@ --- *
88 * Arguments: @c@ = pointer to destination cookie header
89 * @p@ = pointer to source buffer
91 * Use: Unpacks a cookie header from an octet buffer into a
92 * machine-specific but comprehensible structure.
95 #define COOKIE_UNPACK(c, p) do { \
97 const octet *_p = (const octet *)(p); \
98 _c->k = LOAD32(_p + 0); \
99 _c->exp = ((time_t)(((LOAD32(_p + 4) << 16) << 16) & ~MASK32) | \
100 (time_t)LOAD32(_p + 8)); \
103 /*----- Useful shared functions -------------------------------------------*/
105 /* --- @doopen@ --- *
107 * Arguments: @key_file *f@ = pointer to key file block
108 * @unsigned how@ = method to open file with
112 * Use: Opens a key file and handles errors by panicking
116 static void doopen(key_file
*f
, unsigned how
)
118 if (key_open(f
, keyfile
, how
, key_moan
, 0)) {
119 die(EXIT_FAILURE
, "couldn't open file `%s': %s",
120 keyfile
, strerror(errno
));
124 /* --- @doclose@ --- *
126 * Arguments: @key_file *f@ = pointer to key file block
130 * Use: Closes a key file and handles errors by panicking
134 static void doclose(key_file
*f
)
136 switch (key_close(f
)) {
138 die(EXIT_FAILURE
, "couldn't write file `%s': %s",
139 keyfile
, strerror(errno
));
141 die(EXIT_FAILURE
, "keyring file `%s' broken: %s (repair manually)",
142 keyfile
, strerror(errno
));
146 /* --- @getmac@ --- *
148 * Arguments: @key *k@ = key to use
149 * @const char *app@ = application name
151 * Returns: The MAC to use.
153 * Use: Finds the right MAC for the given key.
156 static gmac
*getmac(key
*k
, const char *app
)
173 /* --- Pick out the right MAC --- */
176 if ((q
= key_getattr(0, k
, "mac")) != 0) {
179 } else if (strncmp(k
->type
, app
, n
) == 0 && k
->type
[n
] == '-') {
180 dstr_puts(&d
, k
->type
);
183 die(EXIT_FAILURE
, "no MAC algorithm for key `%s'", t
.buf
);
184 if ((cm
= gmac_byname(p
)) == 0) {
185 die(EXIT_FAILURE
, "MAC algorithm `%s' not found in key `%s'",
189 /* --- Unlock the key --- */
191 kp
.kd
.e
= KENC_BINARY
;
193 if ((e
= key_unpack(&kp
, &k
->k
, &t
)) != 0) {
194 die(EXIT_FAILURE
, "error unpacking key `%s': %s",
195 t
.buf
, key_strerror(e
));
198 /* --- Make the MAC object --- */
200 if (keysz(kb
.sz
, cm
->keysz
) != kb
.sz
)
201 die(EXIT_FAILURE
, "key %s has bad length (%lu) for MAC %s",
202 t
.buf
, (unsigned long)kb
.sz
, cm
->name
);
203 m
= cm
->key(kb
.k
, kb
.sz
);
208 /*----- Command implementation --------------------------------------------*/
210 /* --- @cmd_gen@ --- */
212 static int cmd_gen(int argc
, char *argv
[])
218 const char *tag
= "cookie";
220 cookie c
= { 0, KEXP_EXPIRE
};
225 octet buf
[COOKIE_SZ
];
228 /* --- Various useful flag bits --- */
232 /* --- Parse options for the subcommand --- */
235 static struct option opt
[] = {
236 { "bits", OPTF_ARGREQ
, 0, 'b' },
237 { "expire", OPTF_ARGREQ
, 0, 'e' },
238 { "key", OPTF_ARGREQ
, 0, 'k' },
241 int i
= mdwopt(argc
, argv
, "+b:e:i:t:", opt
, 0, 0, 0);
245 /* --- Handle the various options --- */
249 /* --- Fetch a size in bits --- */
252 if (!(bits
= atoi(optarg
)) || bits
% 8)
253 die(EXIT_FAILURE
, "bad number of bits: `%s'", optarg
);
256 /* --- Fetch an expiry time --- */
259 if (strcmp(optarg
, "forever") == 0)
260 c
.exp
= KEXP_FOREVER
;
261 else if ((c
.exp
= get_date(optarg
, 0)) == -1)
262 die(EXIT_FAILURE
, "bad expiry date: `%s'", optarg
);
265 /* --- Fetch a key type --- */
271 /* --- Other things are bogus --- */
279 /* --- Various sorts of bogosity --- */
281 if (fl
& f_bogus
|| optind
+ 1 < argc
)
283 "Usage: generate [-b BITS] [-e TIME] [-k TAG] [DATA]");
285 /* --- Choose a default expiry time --- */
287 if (c
.exp
== KEXP_EXPIRE
)
288 c
.exp
= time(0) + 7 * 24 * 60 * 60;
290 /* --- Open the key file and get the key --- */
292 doopen(&f
, KOPEN_WRITE
);
293 if ((k
= key_bytag(&f
, tag
)) == 0) {
294 die(EXIT_FAILURE
, "no key with tag `%s' in keyring `%s'",
299 if ((err
= key_used(&f
, k
, c
.exp
)) != 0)
300 die(EXIT_FAILURE
, "can't generate cookie: %s", key_strerror(err
));
301 m
= getmac(k
, "cookie");
302 if (bits
/8 > GM_CLASS(m
)->hashsz
) {
303 die(EXIT_FAILURE
, "inapproriate bit length for `%s' MACs",
307 /* --- Store and MAC the cookie --- */
309 COOKIE_PACK(buf
, &c
);
312 GH_HASH(h
, buf
, sizeof(buf
));
314 GH_HASH(h
, argv
[optind
], strlen(argv
[optind
]));
317 /* --- Encode and emit the finished cookie --- */
321 base64_encode(&b
, buf
, sizeof(buf
), &d
);
322 base64_encode(&b
, t
, bits
/8, &d
);
323 base64_encode(&b
, 0, 0, &d
);
336 /* --- @cmd_verify@ --- */
338 static int cmd_verify(int argc
, char *argv
[])
343 int bits
= -1, minbits
= 32;
352 time_t now
= time(0);
354 /* --- Various useful flag bits --- */
360 /* --- Parse options for the subcommand --- */
363 static struct option opt
[] = {
364 { "bits", OPTF_ARGREQ
, 0, 'b' },
365 { "min-bits", OPTF_ARGREQ
, 0, 'm' },
366 { "forever", 0, 0, 'f' },
367 { "quiet", 0, 0, 'q' },
368 { "verbose", 0, 0, 'v' },
369 { "utc", 0, 0, 'u' },
372 int i
= mdwopt(argc
, argv
, "+b:m:fqvu", opt
, 0, 0, 0);
376 /* --- Handle the various options --- */
380 /* --- Fetch a size in bits --- */
383 if (!(bits
= atoi(optarg
)) || bits
% 8)
384 die(EXIT_FAILURE
, "bad number of bits: `%s'", optarg
);
387 if (!(minbits
= atoi(optarg
)) || minbits
% 8)
388 die(EXIT_FAILURE
, "bad number of bits: `%s'", optarg
);
391 /* --- Miscellaneous flags --- */
406 /* --- Other things are bogus --- */
414 /* --- Various sorts of bogosity --- */
416 if (fl
& f_bogus
|| optind
== argc
|| optind
+ 2 < argc
) {
418 "Usage: verify [-fuqv] [-b BITS] [-m BITS] COOKIE [DATA]");
420 doopen(&f
, KOPEN_READ
);
422 /* --- Decode the base64 wrapping --- */
425 base64_decode(&b
, argv
[optind
], strlen(argv
[optind
]), &d
);
426 base64_decode(&b
, 0, 0, &d
);
428 if (d
.len
< COOKIE_SZ
+ 1) {
429 if (v
) printf("FAIL cookie too small\n");
433 /* --- Extract the relevant details --- */
435 COOKIE_UNPACK(&c
, d
.buf
);
439 if (c
.exp
== KEXP_FOREVER
)
440 strcpy(buf
, "forever");
447 fmt
= "%Y-%m-%d %H:%M:%S UTC";
449 tm
= localtime(&c
.exp
);
450 fmt
= "%Y-%m-%d %H:%M:%S %Z";
452 strftime(buf
, sizeof(buf
), fmt
, tm
);
454 printf("INFO keyid = %08lx; expiry = %s\n", (unsigned long)c
.k
, buf
);
457 /* --- Check the authentication token width --- */
459 cbits
= (d
.len
- COOKIE_SZ
) * 8;
460 if (v
> 2) printf("INFO authentication token width = %i bits\n", cbits
);
462 if (cbits
< minbits
) {
463 if (v
) printf("FAIL authentication token too narrow\n");
468 if (v
) printf("FAIL authentication token width doesn't match\n");
472 /* --- Get the key --- */
474 if ((k
= key_byid(&f
, c
.k
)) == 0) {
475 if (v
) printf("FAIL keyid %08lx unavailable\n", (unsigned long)c
.k
);
479 /* --- Check that the cookie authenticates OK --- */
481 m
= getmac(k
, "cookie");
483 GH_HASH(h
, d
.buf
, COOKIE_SZ
);
484 if (argv
[optind
+ 1])
485 GH_HASH(h
, argv
[optind
+ 1], strlen(argv
[optind
+ 1]));
488 if (memcmp(t
, d
.buf
+ COOKIE_SZ
, cbits
/ 8) != 0) {
489 if (v
) printf("FAIL bad authentication token\n");
493 /* --- See whether the cookie has expired --- */
495 if (c
.exp
== KEXP_FOREVER
) {
496 if (!(fl
& f_forever
)) {
497 if (v
) printf("FAIL forever cookies not allowed\n");
500 if (k
->exp
!= KEXP_FOREVER
) {
501 if (v
) printf("FAIL cookie lasts forever but key will expire\n");
504 } else if (c
.exp
< now
) {
505 if (v
) printf("FAIL cookie has expired\n");
509 if (v
) printf("OK\n");
526 /*----- Main command table ------------------------------------------------*/
528 static int cmd_help(int, char **);
532 listtab[i].name, listtab[i].name) \
533 LI("Message authentication algorithms", mac, \
534 gmactab[i], gmactab[i]->name)
536 MAKELISTTAB(listtab
, LISTS
)
538 static int cmd_show(int argc
, char *argv
[])
540 return (displaylists(listtab
, argv
+ 1));
543 static cmd cmds
[] = {
544 { "help", cmd_help
, "help [COMMAND...]" },
545 { "show", cmd_show
, "show [ITEM...]" },
546 { "generate", cmd_gen
,
547 "generate [-b BITS] [-e TIME] [-k TAG] [DATA]", "\
550 -b, --bits=N Use an N-bit token in the cookie.\n\
551 -e, --expire=TIME Make the cookie expire after TIME.\n\
552 -k, --key=TAG Use key TAG to create the token.\n\
554 { "verify", cmd_verify
,
555 "verify [-fuqv] [-b BITS] [-m BITS] COOKIE [DATA]", "\
558 -b, --bits=N Accept tokens exactly N bits long only.\n\
559 -m, --min-bits=N Accept tokens N bits long or more.\n\
560 -f, --forever Accept cookies which never expire.\n\
561 -u, --utc Output cookie expiry dates in UTC.\n\
562 -q, --quiet Produce less output while checking cookies.\n\
563 -v, --verbose Produce more output while checking cookies.\n\
568 static int cmd_help(int argc
, char *argv
[])
570 sc_help(cmds
, stdout
, argv
+ 1);
574 /*----- Main code ---------------------------------------------------------*/
576 /* --- Helpful GNUy functions --- */
578 static void usage(FILE *fp
)
580 fprintf(fp
, "Usage: %s [-k KEYRING] COMMAND [ARGS]\n", QUIS
);
583 void version(FILE *fp
)
585 fprintf(fp
, "%s, Catacomb version " VERSION
"\n", QUIS
);
588 void help_global(FILE *fp
)
592 Generates and validates cryptographic cookies. Command line options\n\
595 -h, --help [COMMAND] Display this help text (or help for COMMAND).\n\
596 -v, --version Display version number.\n\
597 -u, --usage Display short usage summary.\n\
599 -k, --key-file=FILE Read and write keys in FILE.\n",
605 * Arguments: @int argc@ = number of command line arguments
606 * @char *argv[]@ = array of arguments
608 * Returns: Zero if OK, nonzero if not.
610 * Use: Generates and validates cryptographic cookies.
613 int main(int argc
, char *argv
[])
620 /* --- Initialize the library --- */
625 /* --- Options parsing --- */
628 static struct option opt
[] = {
630 /* --- Standard GNUy help options --- */
632 { "help", 0, 0, 'h' },
633 { "version", 0, 0, 'v' },
634 { "usage", 0, 0, 'u' },
636 /* --- Actual relevant options --- */
638 { "keyring", OPTF_ARGREQ
, 0, 'k' },
640 /* --- Magic terminator --- */
644 int i
= mdwopt(argc
, argv
, "+hvu k:", opt
, 0, 0, 0);
650 /* --- Helpful GNUs --- */
659 sc_help(cmds
, stdout
, argv
+ optind
);
662 /* --- Real genuine useful options --- */
668 /* --- Bogus things --- */
676 if ((f
& f_bogus
) || optind
== argc
) {
681 /* --- Dispatch to appropriate command handler --- */
686 return (findcmd(cmds
, argv
[0])->cmd(argc
, argv
));
692 /*----- That's all, folks -------------------------------------------------*/