X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/fa54fe1eda6977fc8aef0c154f8483e351e20bdd..f52f2db067dc1388b16ab00ddb53e26a381a6e3e:/catcrypt.c diff --git a/catcrypt.c b/catcrypt.c index 08fbb53..6e4f245 100644 --- a/catcrypt.c +++ b/catcrypt.c @@ -7,7 +7,7 @@ * (c) 2004 Straylight/Edgeware */ -/*----- Licensing notice --------------------------------------------------* +/*----- Licensing notice --------------------------------------------------* * * This file is part of Catacomb. * @@ -15,12 +15,12 @@ * it under the terms of the GNU Library General Public License as * published by the Free Software Foundation; either version 2 of the * License, or (at your option) any later version. - * + * * Catacomb is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Library General Public License for more details. - * + * * You should have received a copy of the GNU Library General Public * License along with Catacomb; if not, write to the Free * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, @@ -53,25 +53,6 @@ #include "ectab.h" #include "ptab.h" -/*----- Utilities ---------------------------------------------------------*/ - -/* --- @keyreport@ --- * - * - * Arguments: @const char *file@ = filename containing the error - * @int line@ = line number in file - * @const char *err@ = error text message - * @void *p@ = unimportant pointer - * - * Returns: --- - * - * Use: Reports errors during the opening of a key file. - */ - -static void keyreport(const char *file, int line, const char *err, void *p) -{ - moan("error in keyring `%s' at line `%s': %s", file, line, err); -} - /*----- Static variables --------------------------------------------------*/ static const char *keyring = "keyring"; @@ -92,12 +73,13 @@ static const char *keyring = "keyring"; * MGF (or similar) to make a symmetric encryption and MAC key. * * If the message is signed, there comes a signature chunk. The signature is - * on the further output of the MGF. This means that the recipient can - * modify the message and still have a valid signature, so it's not useful - * for proving things to other people; but it also means that the recipient - * knows that the message is from someone who knows the hash, which limits - * the possiblities to (a) whoever encrypted the message (good!) and (b) - * whoever knows the recipient's private key. + * on the header and key-encapsulation chunks, and further output of the MGF. + * This means that the recipient can modify the message and still have a + * valid signature, so it's not useful for proving things to other people; + * but it also means that the recipient knows that the message is from + * someone who knows the hash, which limits the possiblities to (a) whoever + * encrypted the message (good!) and (b) whoever knows the recipient's + * private key. * * Then come message chunks. Each one begins with a MAC over an implicit * sequence number and the ciphertext. The final chunk's ciphertext is @@ -151,12 +133,12 @@ static int encrypt(int argc, char *argv[]) const char *err; int i; int en; - size_t n; + size_t n, chsz; dstr d = DSTR_INIT; octet *tag, *ct; buf b; size_t seq; - char bb[16384]; + char bb[65536]; unsigned f = 0; key_file kf; key *k; @@ -170,6 +152,7 @@ static int encrypt(int argc, char *argv[]) enc *e; #define f_bogus 1u +#define f_nocheck 2u for (;;) { static const struct option opt[] = { @@ -177,11 +160,12 @@ static int encrypt(int argc, char *argv[]) { "sign-key", OPTF_ARGREQ, 0, 's' }, { "armour", 0, 0, 'a' }, { "armor", 0, 0, 'a' }, - { "format", OPTF_ARGREQ, 0, 'f' }, - { "output", OPTF_ARGREQ, 0, 'o' }, + { "format", OPTF_ARGREQ, 0, 'f' }, + { "output", OPTF_ARGREQ, 0, 'o' }, + { "nocheck", 0, 0, 'C' }, { 0, 0, 0, 0 } }; - i = mdwopt(argc, argv, "k:s:af:o:", opt, 0, 0, 0); + i = mdwopt(argc, argv, "k:s:af:o:C", opt, 0, 0, 0); if (i < 0) break; switch (i) { case 'k': kn = optarg; break; @@ -189,13 +173,14 @@ static int encrypt(int argc, char *argv[]) case 'a': ef = "pem"; break; case 'f': ef = optarg; break; case 'o': of = optarg; break; + case 'C': f |= f_nocheck; break; default: f |= f_bogus; break; } } if (argc - optind > 1 || (f & f_bogus)) die(EXIT_FAILURE, "Usage: encrypt [-OPTIONS] [FILE]"); - if (key_open(&kf, keyring, KOPEN_READ, keyreport, 0)) + if (key_open(&kf, keyring, KOPEN_READ, key_moan, 0)) die(EXIT_FAILURE, "can't open keyring `%s'", keyring); if ((k = key_bytag(&kf, kn)) == 0) die(EXIT_FAILURE, "key `%s' not found", kn); @@ -227,7 +212,7 @@ static int encrypt(int argc, char *argv[]) key_fulltag(k, &d); e = initenc(eo, ofp, "CATCRYPT ENCRYPTED MESSAGE"); km = getkem(k, "cckem", 0); - if ((err = km->ops->check(km)) != 0) + if (!(f & f_nocheck) && (err = km->ops->check(km)) != 0) moan("key %s fails check: %s", d.buf, err); if (sk) { dstr_reset(&d); @@ -245,6 +230,7 @@ static int encrypt(int argc, char *argv[]) buf_putu32(&b, k->id); if (sk) buf_putu32(&b, sk->id); assert(BOK(&b)); + if (s) GH_HASHBUF16(s->h, BBASE(&b), BLEN(&b)); chunk_write(e, &b); /* --- Build the KEM chunk --- */ @@ -254,6 +240,7 @@ static int encrypt(int argc, char *argv[]) die(EXIT_FAILURE, "failed to encapsulate key"); buf_init(&b, d.buf, d.len); BSTEP(&b, d.len); + if (s) GH_HASHBUF16(s->h, BBASE(&b), BLEN(&b)); chunk_write(e, &b); /* --- Write the signature chunk --- */ @@ -267,23 +254,23 @@ static int encrypt(int argc, char *argv[]) buf_init(&b, d.buf, d.len); BSTEP(&b, d.len); chunk_write(e, &b); - } + } /* --- Now do the main crypto --- */ assert(GC_CLASS(c)->blksz <= sizeof(bb)); dstr_ensure(&d, sizeof(bb) + GM_CLASS(m)->hashsz); seq = 0; + chsz = MASK16 - GM_CLASS(m)->hashsz; for (;;) { h = GM_INIT(m); - STORE32(bb, seq); - GH_HASH(h, bb, 4); + GH_HASHU32(h, seq); seq++; if (GC_CLASS(c)->blksz) { GC_ENCRYPT(cx, 0, bb, GC_CLASS(c)->blksz); GC_SETIV(c, bb); } - n = fread(bb, 1, sizeof(bb), fp); + n = fread(bb, 1, chsz, fp); if (!n) break; buf_init(&b, d.buf, d.sz); tag = buf_get(&b, GM_CLASS(m)->hashsz); @@ -314,12 +301,14 @@ static int encrypt(int argc, char *argv[]) freeenc(e); if (s) freesig(s); freekem(km); + if (fp != stdin) fclose(fp); if (of) fclose(ofp); key_close(&kf); dstr_destroy(&d); return (0); #undef f_bogus +#undef f_nocheck } /*---- Decryption ---------------------------------------------------------*/ @@ -354,6 +343,7 @@ static int decrypt(int argc, char *argv[]) #define f_bogus 1u #define f_buffer 2u +#define f_nocheck 4u for (;;) { static const struct option opt[] = { @@ -362,17 +352,19 @@ static int decrypt(int argc, char *argv[]) { "buffer", 0, 0, 'b' }, { "verbose", 0, 0, 'v' }, { "quiet", 0, 0, 'q' }, - { "format", OPTF_ARGREQ, 0, 'f' }, - { "output", OPTF_ARGREQ, 0, 'o' }, + { "nocheck", 0, 0, 'C' }, + { "format", OPTF_ARGREQ, 0, 'f' }, + { "output", OPTF_ARGREQ, 0, 'o' }, { 0, 0, 0, 0 } }; - i = mdwopt(argc, argv, "af:o:qv", opt, 0, 0, 0); + i = mdwopt(argc, argv, "abf:o:qvC", opt, 0, 0, 0); if (i < 0) break; switch (i) { case 'a': ef = "pem"; break; case 'b': f |= f_buffer; break; case 'v': verb++; break; case 'q': if (verb) verb--; break; + case 'C': f |= f_nocheck; break; case 'f': ef = optarg; break; case 'o': of = optarg; break; default: f |= f_bogus; break; @@ -395,7 +387,7 @@ static int decrypt(int argc, char *argv[]) } else optind++; - if (key_open(&kf, keyring, KOPEN_READ, keyreport, 0)) + if (key_open(&kf, keyring, KOPEN_READ, key_moan, 0)) die(EXIT_FAILURE, "can't open keyring `%s'", keyring); e = initdec(eo, fp, checkbdry, "CATCRYPT ENCRYPTED MESSAGE"); @@ -425,6 +417,15 @@ static int decrypt(int argc, char *argv[]) if (verb) printf("FAIL malformed header: junk at end\n"); exit(EXIT_FAILURE); } + if (sk) { + s = getsig(sk, "ccsig", 0); + if (!(f & f_nocheck) && verb && (err = s->ops->check(s)) != 0) { + dstr_reset(&d); + key_fulltag(sk, &d); + printf("WARN verification key %s fails check: %s\n", d.buf, err); + } + GH_HASHBUF16(s->h, BBASE(&b), BSZ(&b)); + } /* --- Find the key --- */ @@ -437,15 +438,11 @@ static int decrypt(int argc, char *argv[]) if (verb) printf("FAIL failed to decapsulate key\n"); exit(EXIT_FAILURE); } + if (s) GH_HASHBUF16(s->h, d.buf, d.len); /* --- Verify the signature, if there is one --- */ if (sk) { - s = getsig(sk, "ccsig", 0); - dstr_reset(&d); - key_fulltag(sk, &d); - if (verb && (err = s->ops->check(s)) != 0) - printf("WARN verification key %s fails check: %s\n", d.buf, err); dstr_reset(&d); dstr_ensure(&d, 1024); GC_ENCRYPT(cx, 0, d.buf, 1024); @@ -460,6 +457,7 @@ static int decrypt(int argc, char *argv[]) key_fulltag(sk, &d); printf("INFO good-signature %s\n", d.buf); } + freesig(s); } else if (verb) printf("INFO no-signature\n"); @@ -487,8 +485,7 @@ static int decrypt(int argc, char *argv[]) GC_SETIV(c, d.buf); } h = GM_INIT(m); - STORE32(d.buf, seq); - GH_HASH(h, d.buf, 4); + GH_HASHU32(h, seq); seq++; chunk_read(e, &d, &b); if ((tag = buf_get(&b, GM_CLASS(m)->hashsz)) == 0) { @@ -501,6 +498,7 @@ static int decrypt(int argc, char *argv[]) printf("FAIL bad ciphertext chunk: authentication failure\n"); exit(EXIT_FAILURE); } + GH_DESTROY(h); if (!BLEFT(&b)) break; GC_DECRYPT(c, BCUR(&b), BCUR(&b), BLEFT(&b)); @@ -522,7 +520,7 @@ static int decrypt(int argc, char *argv[]) rewind(rfp); dstr_reset(&d); dstr_ensure(&d, 65536); - if (ofp == stdout) printf("DATA\n"); + if (verb && ofp == stdout) printf("DATA\n"); for (;;) { n = fread(d.buf, 1, d.sz, rfp); if (!n) break; @@ -533,7 +531,7 @@ static int decrypt(int argc, char *argv[]) die(EXIT_FAILURE, "error unbuffering output: %s", strerror(errno)); } if (ofp && (fflush(ofp) || ferror(ofp) || fclose(ofp))) - die(EXIT_FAILURE, "error writing output: %s", strerror(errno)); + die(EXIT_FAILURE, "error writing output: %s", strerror(errno)); e->ops->decdone(e); if (verb && ofp != stdout) @@ -543,6 +541,7 @@ static int decrypt(int argc, char *argv[]) GC_DESTROY(cx); GM_DESTROY(m); freekem(km); + if (fp != stdin) fclose(fp); if (of) fclose(ofp); key_close(&kf); dstr_destroy(&d); @@ -550,6 +549,7 @@ static int decrypt(int argc, char *argv[]) #undef f_bogus #undef f_buffer +#undef f_nocheck } /*----- Main code ---------------------------------------------------------*/ @@ -585,7 +585,7 @@ static cmd cmdtab[] = { CMD_ENCODE, CMD_DECODE, { "encrypt", encrypt, - "encrypt [-a] [-k TAG] [-s TAG] [-f FORMAT]\n\t\ + "encrypt [-aC] [-k TAG] [-s TAG] [-f FORMAT]\n\t\ [-o OUTPUT] [FILE]", "\ Options:\n\ \n\ @@ -594,9 +594,10 @@ Options:\n\ -k, --key=TAG Use public encryption key named by TAG.\n\ -s, --sign-key=TAG Use private signature key named by TAG.\n\ -o, --output=FILE Write output to FILE.\n\ +-C, --nocheck Don't check the public key.\n\ " }, { "decrypt", decrypt, - "decrypt [-abqv] [-f FORMAT] [-o OUTPUT] [FILE]", "\ + "decrypt [-abqvC] [-f FORMAT] [-o OUTPUT] [FILE]", "\ Options:\n\ \n\ -a, --armour Same as `-f pem'.\n\ @@ -605,6 +606,7 @@ Options:\n\ -o, --output=FILE Write output to FILE.\n\ -q, --quiet Produce fewer messages.\n\ -v, --verbose Produce more verbose messages.\n\ +-C, --nocheck Don't check the private key.\n\ " }, /* ' emacs is confused */ { 0, 0, 0 } };