5 * Command-line encryption tool
7 * (c) 2004 Straylight/Edgeware
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 Library General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (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 Library General Public License for more details.
24 * You should have received a copy of the GNU Library General Public
25 * License along with Catacomb; if not, write to the Free
26 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
30 /*----- Header files ------------------------------------------------------*/
39 #include <mLib/base64.h>
40 #include <mLib/dstr.h>
41 #include <mLib/mdwopt.h>
42 #include <mLib/quis.h>
43 #include <mLib/report.h>
56 /*----- Utilities ---------------------------------------------------------*/
58 /* --- @keyreport@ --- *
60 * Arguments: @const char *file@ = filename containing the error
61 * @int line@ = line number in file
62 * @const char *err@ = error text message
63 * @void *p@ = unimportant pointer
67 * Use: Reports errors during the opening of a key file.
70 static void keyreport(const char *file, int line, const char *err, void *p)
72 moan("error in keyring `%s' at line `%s': %s", file, line, err);
75 /*----- Static variables --------------------------------------------------*/
77 static const char *keyring = "keyring";
79 /*----- Data format -------------------------------------------------------*/
83 * The encrypted message is divided into chunks, each preceded by a two-octet
84 * length. The chunks don't need to be large -- the idea is that we can
85 * stream the chunks in and out.
87 * The first chunk is a header. It contains the decryption key-id, and maybe
88 * the verification key-id if the message is signed.
90 * Next comes the key-encapsulation chunk. This is decrypted in some
91 * KEM-specific way to yield a secret hash. The hash is expanded using an
92 * MGF (or similar) to make a symmetric encryption and MAC key.
94 * If the message is signed, there comes a signature chunk. The signature is
95 * on the further output of the MGF. This means that the recipient can
96 * modify the message and still have a valid signature, so it's not useful
97 * for proving things to other people; but it also means that the recipient
98 * knows that the message is from someone who knows the hash, which limits
99 * the possiblities to (a) whoever encrypted the message (good!) and (b)
100 * whoever knows the recipient's private key.
102 * Then come message chunks. Each one begins with a MAC over an implicit
103 * sequence number and the ciphertext. The final chunk's ciphertext is
104 * empty; no other chunk is empty. Thus can the correct end-of-file be
108 /*----- Chunk I/O ---------------------------------------------------------*/
110 static void chunk_write(enc *e, buf *b)
116 if (e->ops->write(e, l, 2) ||
117 e->ops->write(e, BBASE(b), BLEN(b)))
118 die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
121 static void chunk_read(enc *e, dstr *d, buf *b)
128 if (e->ops->read(e, l, 2) != 2)
132 if (e->ops->read(e, d->buf, n) != n)
135 buf_init(b, d->buf, d->len);
139 if (!errno) die(EXIT_FAILURE, "unexpected end-of-file on input");
140 else die(EXIT_FAILURE, "error reading input: %s", strerror(errno));
143 /*----- Encryption --------------------------------------------------------*/
145 static int encrypt(int argc, char *argv[])
147 const char *of = 0, *kn = "ccrypt", *skn = 0;
150 const char *ef = "binary";
175 static const struct option opt[] = {
176 { "key", OPTF_ARGREQ, 0, 'k' },
177 { "sign-key", OPTF_ARGREQ, 0, 's' },
178 { "armour", 0, 0, 'a' },
179 { "armor", 0, 0, 'a' },
180 { "format", OPTF_ARGREQ, 0, 'f' },
181 { "output", OPTF_ARGREQ, 0, 'o' },
184 i = mdwopt(argc, argv, "k:s:af:o:", opt, 0, 0, 0);
187 case 'k': kn = optarg; break;
188 case 's': skn = optarg; break;
189 case 'a': ef = "pem"; break;
190 case 'f': ef = optarg; break;
191 case 'o': of = optarg; break;
192 default: f |= f_bogus; break;
195 if (argc - optind > 1 || (f & f_bogus))
196 die(EXIT_FAILURE, "Usage: encrypt [-OPTIONS] [FILE]");
198 if (key_open(&kf, keyring, KOPEN_READ, keyreport, 0))
199 die(EXIT_FAILURE, "can't open keyring `%s'", keyring);
200 if ((k = key_bytag(&kf, kn)) == 0)
201 die(EXIT_FAILURE, "key `%s' not found", kn);
202 if (skn && (sk = key_bytag(&kf, skn)) == 0)
203 die(EXIT_FAILURE, "key `%s' not found", skn);
205 if ((eo = getenc(ef)) == 0)
206 die(EXIT_FAILURE, "encoding `%s' not found", ef);
210 else if (strcmp(argv[optind], "-") == 0) {
213 } else if ((fp = fopen(argv[optind], "rb")) == 0) {
214 die(EXIT_FAILURE, "couldn't open file `%s': %s",
215 argv[optind], strerror(errno));
219 if (!of || strcmp(of, "-") == 0)
221 else if ((ofp = fopen(of, eo->wmode)) == 0) {
222 die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
223 ofp, strerror(errno));
228 e = initenc(eo, ofp, "CATCRYPT ENCRYPTED MESSAGE");
229 km = getkem(k, "cckem", 0);
230 if ((err = km->ops->check(km)) != 0)
231 moan("key %s fails check: %s", d.buf, err);
235 s = getsig(sk, "ccsig", 1);
236 if ((err = s->ops->check(s)) != 0)
237 moan("key %s fails check: %s", d.buf, err);
240 /* --- Build the header chunk --- */
243 dstr_ensure(&d, 256);
244 buf_init(&b, d.buf, 256);
245 buf_putu32(&b, k->id);
246 if (sk) buf_putu32(&b, sk->id);
250 /* --- Build the KEM chunk --- */
253 if (setupkem(km, &d, &cx, &c, &m))
254 die(EXIT_FAILURE, "failed to encapsulate key");
255 buf_init(&b, d.buf, d.len);
259 /* --- Write the signature chunk --- */
262 GC_ENCRYPT(cx, 0, bb, 1024);
263 GH_HASH(s->h, bb, 1024);
265 if ((en = s->ops->doit(s, &d)) != 0)
266 die(EXIT_FAILURE, "error creating signature: %s", key_strerror(en));
267 buf_init(&b, d.buf, d.len);
272 /* --- Now do the main crypto --- */
274 assert(GC_CLASS(c)->blksz <= sizeof(bb));
275 dstr_ensure(&d, sizeof(bb) + GM_CLASS(m)->hashsz);
282 if (GC_CLASS(c)->blksz) {
283 GC_ENCRYPT(cx, 0, bb, GC_CLASS(c)->blksz);
286 n = fread(bb, 1, sizeof(bb), fp);
288 buf_init(&b, d.buf, d.sz);
289 tag = buf_get(&b, GM_CLASS(m)->hashsz);
291 assert(tag); assert(ct);
292 GC_ENCRYPT(c, bb, ct, n);
299 /* --- Final terminator packet --- */
301 buf_init(&b, d.buf, d.sz);
302 tag = buf_get(&b, GM_CLASS(m)->hashsz);
308 /* --- All done --- */
325 /*---- Decryption ---------------------------------------------------------*/
327 static int decrypt(int argc, char *argv[])
330 FILE *ofp = 0, *rfp = 0;
332 const char *ef = "binary";
359 static const struct option opt[] = {
360 { "armour", 0, 0, 'a' },
361 { "armor", 0, 0, 'a' },
362 { "buffer", 0, 0, 'b' },
363 { "verbose", 0, 0, 'v' },
364 { "quiet", 0, 0, 'q' },
365 { "format", OPTF_ARGREQ, 0, 'f' },
366 { "output", OPTF_ARGREQ, 0, 'o' },
369 i = mdwopt(argc, argv, "af:o:qv", opt, 0, 0, 0);
372 case 'a': ef = "pem"; break;
373 case 'b': f |= f_buffer; break;
374 case 'v': verb++; break;
375 case 'q': if (verb) verb--; break;
376 case 'f': ef = optarg; break;
377 case 'o': of = optarg; break;
378 default: f |= f_bogus; break;
381 if (argc - optind > 1 || (f & f_bogus))
382 die(EXIT_FAILURE, "Usage: decrypt [-OPTIONS] [FILE]");
384 if ((eo = getenc(ef)) == 0)
385 die(EXIT_FAILURE, "encoding `%s' not found", ef);
389 else if (strcmp(argv[optind], "-") == 0) {
392 } else if ((fp = fopen(argv[optind], eo->rmode)) == 0) {
393 die(EXIT_FAILURE, "couldn't open file `%s': %s",
394 argv[optind], strerror(errno));
398 if (key_open(&kf, keyring, KOPEN_READ, keyreport, 0))
399 die(EXIT_FAILURE, "can't open keyring `%s'", keyring);
401 e = initdec(eo, fp, checkbdry, "CATCRYPT ENCRYPTED MESSAGE");
403 /* --- Read the header chunk --- */
405 chunk_read(e, &d, &b);
406 if (buf_getu32(&b, &id)) {
407 if (verb) printf("FAIL malformed header: missing keyid\n");
410 if ((k = key_byid(&kf, id)) == 0) {
411 if (verb) printf("FAIL key id %08lx not found\n", (unsigned long)id);
415 if (buf_getu32(&b, &id)) {
416 if (verb) printf("FAIL malformed header: missing signature keyid\n");
419 if ((sk = key_byid(&kf, id)) == 0) {
420 if (verb) printf("FAIL key id %08lx not found\n", (unsigned long)id);
425 if (verb) printf("FAIL malformed header: junk at end\n");
429 /* --- Find the key --- */
431 km = getkem(k, "cckem", 1);
433 /* --- Read the KEM chunk --- */
435 chunk_read(e, &d, &b);
436 if (setupkem(km, &d, &cx, &c, &m)) {
437 if (verb) printf("FAIL failed to decapsulate key\n");
441 /* --- Verify the signature, if there is one --- */
444 s = getsig(sk, "ccsig", 0);
447 if (verb && (err = s->ops->check(s)) != 0)
448 printf("WARN verification key %s fails check: %s\n", d.buf, err);
450 dstr_ensure(&d, 1024);
451 GC_ENCRYPT(cx, 0, d.buf, 1024);
452 GH_HASH(s->h, d.buf, 1024);
453 chunk_read(e, &d, &b);
454 if (s->ops->doit(s, &d)) {
455 if (verb) printf("FAIL signature verification failed\n");
461 printf("INFO good-signature %s\n", d.buf);
464 printf("INFO no-signature\n");
466 /* --- Now decrypt the main body --- */
468 if (!of || strcmp(of, "-") == 0) {
472 if (!(f & f_buffer)) {
473 if ((ofp = fopen(of, "wb")) == 0) {
474 die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
475 ofp, strerror(errno));
478 } else if ((rfp = tmpfile()) == 0)
479 die(EXIT_FAILURE, "couldn't create temporary file: %s", strerror(errno));
482 dstr_ensure(&d, GC_CLASS(c)->blksz);
485 if (GC_CLASS(c)->blksz) {
486 GC_ENCRYPT(cx, 0, d.buf, GC_CLASS(c)->blksz);
491 GH_HASH(h, d.buf, 4);
493 chunk_read(e, &d, &b);
494 if ((tag = buf_get(&b, GM_CLASS(m)->hashsz)) == 0) {
495 if (verb) printf("FAIL bad ciphertext chunk: no tag\n");
498 GH_HASH(h, BCUR(&b), BLEFT(&b));
499 if (memcmp(tag, GH_DONE(h, 0), GM_CLASS(m)->hashsz) != 0) {
501 printf("FAIL bad ciphertext chunk: authentication failure\n");
506 GC_DECRYPT(c, BCUR(&b), BCUR(&b), BLEFT(&b));
507 if (fwrite(BCUR(&b), 1, BLEFT(&b), rfp) != BLEFT(&b)) {
508 if (verb) printf("FAIL error writing output: %s\n", strerror(errno));
513 if (fflush(rfp) || ferror(rfp)) {
514 if (verb) printf("FAIL error writing output: %s\n", strerror(errno));
518 if (!ofp && (ofp = fopen(of, "wb")) == 0) {
519 die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
520 of, strerror(errno));
524 dstr_ensure(&d, 65536);
525 if (ofp == stdout) printf("DATA\n");
527 n = fread(d.buf, 1, d.sz, rfp);
529 if (fwrite(d.buf, 1, n, ofp) < n)
530 die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
532 if (ferror(rfp) || fclose(rfp))
533 die(EXIT_FAILURE, "error unbuffering output: %s", strerror(errno));
535 if (ofp && (fflush(ofp) || ferror(ofp) || fclose(ofp)))
536 die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
539 if (verb && ofp != stdout)
540 printf("OK decrypted successfully\n");
555 /*----- Main code ---------------------------------------------------------*/
559 listtab[i].name, listtab[i].name) \
560 LI("Key-encapsulation mechanisms", kem, \
561 kemtab[i].name, kemtab[i].name) \
562 LI("Signature schemes", sig, \
563 sigtab[i].name, sigtab[i].name) \
564 LI("Encodings", enc, \
565 enctab[i].name, enctab[i].name) \
566 LI("Symmetric encryption algorithms", cipher, \
567 gciphertab[i], gciphertab[i]->name) \
568 LI("Hash functions", hash, \
569 ghashtab[i], ghashtab[i]->name) \
570 LI("Message authentication codes", mac, \
571 gmactab[i], gmactab[i]->name)
573 MAKELISTTAB(listtab, LISTS)
575 int cmd_show(int argc, char *argv[])
577 return (displaylists(listtab, argv + 1));
580 static int cmd_help(int, char **);
582 static cmd cmdtab[] = {
583 { "help", cmd_help, "help [COMMAND...]" },
584 { "show", cmd_show, "show [ITEM...]" },
587 { "encrypt", encrypt,
588 "encrypt [-a] [-k TAG] [-s TAG] [-f FORMAT]\n\t\
589 [-o OUTPUT] [FILE]", "\
592 -a, --armour Same as `-f pem'.\n\
593 -f, --format=FORMAT Encode as FORMAT.\n\
594 -k, --key=TAG Use public encryption key named by TAG.\n\
595 -s, --sign-key=TAG Use private signature key named by TAG.\n\
596 -o, --output=FILE Write output to FILE.\n\
598 { "decrypt", decrypt,
599 "decrypt [-abqv] [-f FORMAT] [-o OUTPUT] [FILE]", "\
602 -a, --armour Same as `-f pem'.\n\
603 -b, --buffer Buffer output until we're sure we have it all.\n\
604 -f, --format=FORMAT Decode as FORMAT.\n\
605 -o, --output=FILE Write output to FILE.\n\
606 -q, --quiet Produce fewer messages.\n\
607 -v, --verbose Produce more verbose messages.\n\
608 " }, /* ' emacs is confused */
612 static int cmd_help(int argc, char **argv)
614 sc_help(cmdtab, stdout, argv + 1);
618 void version(FILE *fp)
620 pquis(fp, "$, Catacomb version " VERSION "\n");
623 static void usage(FILE *fp)
625 pquis(fp, "Usage: $ [-k KEYRING] COMMAND [ARGS]\n");
628 void help_global(FILE *fp)
632 Encrypt and decrypt files.\n\
634 Global command-line options:\n\
636 -h, --help [COMMAND...] Show this help message, or help for COMMANDs.\n\
637 -v, --version Show program version number.\n\
638 -u, --usage Show a terse usage message.\n\
640 -k, --keyring=FILE Read keys from FILE.\n",
646 * Arguments: @int argc@ = number of command line arguments
647 * @char *argv[]@ = vector of command line arguments
649 * Returns: Zero if successful, nonzero otherwise.
651 * Use: Encrypts or decrypts files.
654 int main(int argc, char *argv[])
660 /* --- Initialize the library --- */
664 rand_noisesrc(RAND_GLOBAL, &noise_source);
665 rand_seed(RAND_GLOBAL, 160);
667 /* --- Parse options --- */
670 static struct option opts[] = {
671 { "help", 0, 0, 'h' },
672 { "version", 0, 0, 'v' },
673 { "usage", 0, 0, 'u' },
674 { "keyring", OPTF_ARGREQ, 0, 'k' },
677 int i = mdwopt(argc, argv, "+hvu k:", opts, 0, 0, 0);
682 sc_help(cmdtab, stdout, argv + optind);
704 if (f & f_bogus || argc < 1) {
709 /* --- Dispatch to the correct subcommand handler --- */
711 return (findcmd(cmdtab, argv[0])->cmd(argc, argv));
716 /*----- That's all, folks -------------------------------------------------*/