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 /*----- Static variables --------------------------------------------------*/
58 static const char *keyring = "keyring";
60 /*----- Data format -------------------------------------------------------*/
64 * The encrypted message is divided into chunks, each preceded by a two-octet
65 * length. The chunks don't need to be large -- the idea is that we can
66 * stream the chunks in and out.
68 * The first chunk is a header. It contains the decryption key-id, and maybe
69 * the verification key-id if the message is signed.
71 * Next comes the key-encapsulation chunk. This is decrypted in some
72 * KEM-specific way to yield a secret hash. The hash is expanded using an
73 * MGF (or similar) to make a symmetric encryption and MAC key.
75 * If the message is signed, there comes a signature chunk. The signature is
76 * on the header and key-encapsulation chunks, and further output of the MGF.
77 * This means that the recipient can modify the message and still have a
78 * valid signature, so it's not useful for proving things to other people;
79 * but it also means that the recipient knows that the message is from
80 * someone who knows the hash, which limits the possiblities to (a) whoever
81 * encrypted the message (good!) and (b) whoever knows the recipient's
84 * Then come message chunks. Each one begins with a MAC over an implicit
85 * sequence number and the ciphertext. The final chunk's ciphertext is
86 * empty; no other chunk is empty. Thus can the correct end-of-file be
90 /*----- Chunk I/O ---------------------------------------------------------*/
92 static void chunk_write(enc *e, buf *b)
98 if (e->ops->write(e, l, 2) ||
99 e->ops->write(e, BBASE(b), BLEN(b)))
100 die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
103 static void chunk_read(enc *e, dstr *d, buf *b)
110 if (e->ops->read(e, l, 2) != 2)
114 if (e->ops->read(e, d->buf, n) != n)
117 buf_init(b, d->buf, d->len);
121 if (!errno) die(EXIT_FAILURE, "unexpected end-of-file on input");
122 else die(EXIT_FAILURE, "error reading input: %s", strerror(errno));
125 /*----- Encryption --------------------------------------------------------*/
127 static int encrypt(int argc, char *argv[])
129 const char *of = 0, *kn = "ccrypt", *skn = 0;
132 const char *ef = "binary";
158 static const struct option opt[] = {
159 { "key", OPTF_ARGREQ, 0, 'k' },
160 { "sign-key", OPTF_ARGREQ, 0, 's' },
161 { "armour", 0, 0, 'a' },
162 { "armor", 0, 0, 'a' },
163 { "format", OPTF_ARGREQ, 0, 'f' },
164 { "output", OPTF_ARGREQ, 0, 'o' },
165 { "nocheck", 0, 0, 'C' },
168 i = mdwopt(argc, argv, "k:s:af:o:C", opt, 0, 0, 0);
171 case 'k': kn = optarg; break;
172 case 's': skn = optarg; break;
173 case 'a': ef = "pem"; break;
174 case 'f': ef = optarg; break;
175 case 'o': of = optarg; break;
176 case 'C': f |= f_nocheck; break;
177 default: f |= f_bogus; break;
180 if (argc - optind > 1 || (f & f_bogus))
181 die(EXIT_FAILURE, "Usage: encrypt [-OPTIONS] [FILE]");
183 if (key_open(&kf, keyring, KOPEN_READ, key_moan, 0))
184 die(EXIT_FAILURE, "can't open keyring `%s'", keyring);
185 if ((k = key_bytag(&kf, kn)) == 0)
186 die(EXIT_FAILURE, "key `%s' not found", kn);
187 if (skn && (sk = key_bytag(&kf, skn)) == 0)
188 die(EXIT_FAILURE, "key `%s' not found", skn);
190 if ((eo = getenc(ef)) == 0)
191 die(EXIT_FAILURE, "encoding `%s' not found", ef);
195 else if (strcmp(argv[optind], "-") == 0) {
198 } else if ((fp = fopen(argv[optind], "rb")) == 0) {
199 die(EXIT_FAILURE, "couldn't open file `%s': %s",
200 argv[optind], strerror(errno));
204 if (!of || strcmp(of, "-") == 0)
206 else if ((ofp = fopen(of, eo->wmode)) == 0) {
207 die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
208 ofp, strerror(errno));
213 e = initenc(eo, ofp, "CATCRYPT ENCRYPTED MESSAGE");
214 km = getkem(k, "cckem", 0);
215 if (!(f & f_nocheck) && (err = km->ops->check(km)) != 0)
216 moan("key %s fails check: %s", d.buf, err);
220 s = getsig(sk, "ccsig", 1);
221 if ((err = s->ops->check(s)) != 0)
222 moan("key %s fails check: %s", d.buf, err);
225 /* --- Build the header chunk --- */
228 dstr_ensure(&d, 256);
229 buf_init(&b, d.buf, 256);
230 buf_putu32(&b, k->id);
231 if (sk) buf_putu32(&b, sk->id);
233 if (s) GH_HASHBUF16(s->h, BBASE(&b), BLEN(&b));
236 /* --- Build the KEM chunk --- */
239 if (setupkem(km, &d, &cx, &c, &m))
240 die(EXIT_FAILURE, "failed to encapsulate key");
241 buf_init(&b, d.buf, d.len);
243 if (s) GH_HASHBUF16(s->h, BBASE(&b), BLEN(&b));
246 /* --- Write the signature chunk --- */
249 GC_ENCRYPT(cx, 0, bb, 1024);
250 GH_HASH(s->h, bb, 1024);
252 if ((en = s->ops->doit(s, &d)) != 0)
253 die(EXIT_FAILURE, "error creating signature: %s", key_strerror(en));
254 buf_init(&b, d.buf, d.len);
259 /* --- Now do the main crypto --- */
261 assert(GC_CLASS(c)->blksz <= sizeof(bb));
262 dstr_ensure(&d, sizeof(bb) + GM_CLASS(m)->hashsz);
268 if (GC_CLASS(c)->blksz) {
269 GC_ENCRYPT(cx, 0, bb, GC_CLASS(c)->blksz);
272 n = fread(bb, 1, sizeof(bb), fp);
274 buf_init(&b, d.buf, d.sz);
275 tag = buf_get(&b, GM_CLASS(m)->hashsz);
277 assert(tag); assert(ct);
278 GC_ENCRYPT(c, bb, ct, n);
285 /* --- Final terminator packet --- */
287 buf_init(&b, d.buf, d.sz);
288 tag = buf_get(&b, GM_CLASS(m)->hashsz);
294 /* --- All done --- */
303 if (fp != stdin) fclose(fp);
313 /*---- Decryption ---------------------------------------------------------*/
315 static int decrypt(int argc, char *argv[])
318 FILE *ofp = 0, *rfp = 0;
320 const char *ef = "binary";
348 static const struct option opt[] = {
349 { "armour", 0, 0, 'a' },
350 { "armor", 0, 0, 'a' },
351 { "buffer", 0, 0, 'b' },
352 { "verbose", 0, 0, 'v' },
353 { "quiet", 0, 0, 'q' },
354 { "nocheck", 0, 0, 'C' },
355 { "format", OPTF_ARGREQ, 0, 'f' },
356 { "output", OPTF_ARGREQ, 0, 'o' },
359 i = mdwopt(argc, argv, "abf:o:qvC", opt, 0, 0, 0);
362 case 'a': ef = "pem"; break;
363 case 'b': f |= f_buffer; break;
364 case 'v': verb++; break;
365 case 'q': if (verb) verb--; break;
366 case 'C': f |= f_nocheck; break;
367 case 'f': ef = optarg; break;
368 case 'o': of = optarg; break;
369 default: f |= f_bogus; break;
372 if (argc - optind > 1 || (f & f_bogus))
373 die(EXIT_FAILURE, "Usage: decrypt [-OPTIONS] [FILE]");
375 if ((eo = getenc(ef)) == 0)
376 die(EXIT_FAILURE, "encoding `%s' not found", ef);
380 else if (strcmp(argv[optind], "-") == 0) {
383 } else if ((fp = fopen(argv[optind], eo->rmode)) == 0) {
384 die(EXIT_FAILURE, "couldn't open file `%s': %s",
385 argv[optind], strerror(errno));
389 if (key_open(&kf, keyring, KOPEN_READ, key_moan, 0))
390 die(EXIT_FAILURE, "can't open keyring `%s'", keyring);
392 e = initdec(eo, fp, checkbdry, "CATCRYPT ENCRYPTED MESSAGE");
394 /* --- Read the header chunk --- */
396 chunk_read(e, &d, &b);
397 if (buf_getu32(&b, &id)) {
398 if (verb) printf("FAIL malformed header: missing keyid\n");
401 if ((k = key_byid(&kf, id)) == 0) {
402 if (verb) printf("FAIL key id %08lx not found\n", (unsigned long)id);
406 if (buf_getu32(&b, &id)) {
407 if (verb) printf("FAIL malformed header: missing signature keyid\n");
410 if ((sk = key_byid(&kf, id)) == 0) {
411 if (verb) printf("FAIL key id %08lx not found\n", (unsigned long)id);
416 if (verb) printf("FAIL malformed header: junk at end\n");
420 s = getsig(sk, "ccsig", 0);
421 if (!(f & f_nocheck) && verb && (err = s->ops->check(s)) != 0) {
424 printf("WARN verification key %s fails check: %s\n", d.buf, err);
426 GH_HASHBUF16(s->h, BBASE(&b), BSZ(&b));
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");
440 if (s) GH_HASHBUF16(s->h, d.buf, d.len);
442 /* --- Verify the signature, if there is one --- */
446 dstr_ensure(&d, 1024);
447 GC_ENCRYPT(cx, 0, d.buf, 1024);
448 GH_HASH(s->h, d.buf, 1024);
449 chunk_read(e, &d, &b);
450 if (s->ops->doit(s, &d)) {
451 if (verb) printf("FAIL signature verification failed\n");
457 printf("INFO good-signature %s\n", d.buf);
461 printf("INFO no-signature\n");
463 /* --- Now decrypt the main body --- */
465 if (!of || strcmp(of, "-") == 0) {
469 if (!(f & f_buffer)) {
470 if ((ofp = fopen(of, "wb")) == 0) {
471 die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
472 ofp, strerror(errno));
475 } else if ((rfp = tmpfile()) == 0)
476 die(EXIT_FAILURE, "couldn't create temporary file: %s", strerror(errno));
479 dstr_ensure(&d, GC_CLASS(c)->blksz);
482 if (GC_CLASS(c)->blksz) {
483 GC_ENCRYPT(cx, 0, d.buf, GC_CLASS(c)->blksz);
489 chunk_read(e, &d, &b);
490 if ((tag = buf_get(&b, GM_CLASS(m)->hashsz)) == 0) {
491 if (verb) printf("FAIL bad ciphertext chunk: no tag\n");
494 GH_HASH(h, BCUR(&b), BLEFT(&b));
495 if (memcmp(tag, GH_DONE(h, 0), GM_CLASS(m)->hashsz) != 0) {
497 printf("FAIL bad ciphertext chunk: authentication failure\n");
503 GC_DECRYPT(c, BCUR(&b), BCUR(&b), BLEFT(&b));
504 if (fwrite(BCUR(&b), 1, BLEFT(&b), rfp) != BLEFT(&b)) {
505 if (verb) printf("FAIL error writing output: %s\n", strerror(errno));
510 if (fflush(rfp) || ferror(rfp)) {
511 if (verb) printf("FAIL error writing output: %s\n", strerror(errno));
515 if (!ofp && (ofp = fopen(of, "wb")) == 0) {
516 die(EXIT_FAILURE, "couldn't open file `%s' for output: %s",
517 of, strerror(errno));
521 dstr_ensure(&d, 65536);
522 if (verb && ofp == stdout) printf("DATA\n");
524 n = fread(d.buf, 1, d.sz, rfp);
526 if (fwrite(d.buf, 1, n, ofp) < n)
527 die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
529 if (ferror(rfp) || fclose(rfp))
530 die(EXIT_FAILURE, "error unbuffering output: %s", strerror(errno));
532 if (ofp && (fflush(ofp) || ferror(ofp) || fclose(ofp)))
533 die(EXIT_FAILURE, "error writing output: %s", strerror(errno));
536 if (verb && ofp != stdout)
537 printf("OK decrypted successfully\n");
543 if (fp != stdin) fclose(fp);
554 /*----- Main code ---------------------------------------------------------*/
558 listtab[i].name, listtab[i].name) \
559 LI("Key-encapsulation mechanisms", kem, \
560 kemtab[i].name, kemtab[i].name) \
561 LI("Signature schemes", sig, \
562 sigtab[i].name, sigtab[i].name) \
563 LI("Encodings", enc, \
564 enctab[i].name, enctab[i].name) \
565 LI("Symmetric encryption algorithms", cipher, \
566 gciphertab[i], gciphertab[i]->name) \
567 LI("Hash functions", hash, \
568 ghashtab[i], ghashtab[i]->name) \
569 LI("Message authentication codes", mac, \
570 gmactab[i], gmactab[i]->name)
572 MAKELISTTAB(listtab, LISTS)
574 int cmd_show(int argc, char *argv[])
576 return (displaylists(listtab, argv + 1));
579 static int cmd_help(int, char **);
581 static cmd cmdtab[] = {
582 { "help", cmd_help, "help [COMMAND...]" },
583 { "show", cmd_show, "show [ITEM...]" },
586 { "encrypt", encrypt,
587 "encrypt [-aC] [-k TAG] [-s TAG] [-f FORMAT]\n\t\
588 [-o OUTPUT] [FILE]", "\
591 -a, --armour Same as `-f pem'.\n\
592 -f, --format=FORMAT Encode as FORMAT.\n\
593 -k, --key=TAG Use public encryption key named by TAG.\n\
594 -s, --sign-key=TAG Use private signature key named by TAG.\n\
595 -o, --output=FILE Write output to FILE.\n\
596 -C, --nocheck Don't check the public key.\n\
598 { "decrypt", decrypt,
599 "decrypt [-abqvC] [-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 -C, --nocheck Don't check the private key.\n\
609 " }, /* ' emacs is confused */
613 static int cmd_help(int argc, char **argv)
615 sc_help(cmdtab, stdout, argv + 1);
619 void version(FILE *fp)
621 pquis(fp, "$, Catacomb version " VERSION "\n");
624 static void usage(FILE *fp)
626 pquis(fp, "Usage: $ [-k KEYRING] COMMAND [ARGS]\n");
629 void help_global(FILE *fp)
633 Encrypt and decrypt files.\n\
635 Global command-line options:\n\
637 -h, --help [COMMAND...] Show this help message, or help for COMMANDs.\n\
638 -v, --version Show program version number.\n\
639 -u, --usage Show a terse usage message.\n\
641 -k, --keyring=FILE Read keys from FILE.\n",
647 * Arguments: @int argc@ = number of command line arguments
648 * @char *argv[]@ = vector of command line arguments
650 * Returns: Zero if successful, nonzero otherwise.
652 * Use: Encrypts or decrypts files.
655 int main(int argc, char *argv[])
661 /* --- Initialize the library --- */
665 rand_noisesrc(RAND_GLOBAL, &noise_source);
666 rand_seed(RAND_GLOBAL, 160);
668 /* --- Parse options --- */
671 static struct option opts[] = {
672 { "help", 0, 0, 'h' },
673 { "version", 0, 0, 'v' },
674 { "usage", 0, 0, 'u' },
675 { "keyring", OPTF_ARGREQ, 0, 'k' },
678 int i = mdwopt(argc, argv, "+hvu k:", opts, 0, 0, 0);
683 sc_help(cmdtab, stdout, argv + optind);
705 if (f & f_bogus || argc < 1) {
710 /* --- Dispatch to the correct subcommand handler --- */
712 return (findcmd(cmdtab, argv[0])->cmd(argc, argv));
717 /*----- That's all, folks -------------------------------------------------*/