X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/bd5efd74a96ea9e7ccad0577bc4d94df25109f99..5c3f75ec49019d160806489824fc76652a2ef444:/dsig.c diff --git a/dsig.c b/dsig.c index c5eb5af..2aeb9ef 100644 --- a/dsig.c +++ b/dsig.c @@ -1,6 +1,6 @@ /* -*-c-*- * - * $Id: dsig.c,v 1.7 2001/02/23 09:04:17 mdw Exp $ + * $Id: dsig.c,v 1.12 2004/04/17 09:58:37 mdw Exp $ * * Verify signatures on distribuitions of files * @@ -27,34 +27,6 @@ * MA 02111-1307, USA. */ -/*----- Revision history --------------------------------------------------* - * - * $Log: dsig.c,v $ - * Revision 1.7 2001/02/23 09:04:17 mdw - * Add new hash functions. Provide full help for subcommands. Run the - * hash function over parts of the header in a canonical order. - * - * Revision 1.6 2000/12/06 20:33:27 mdw - * Make flags be macros rather than enumerations, to ensure that they're - * unsigned. - * - * Revision 1.5 2000/10/08 12:12:09 mdw - * Shut up some warnings. - * - * Revision 1.4 2000/08/04 23:23:44 mdw - * Various fixes. - * - * Revision 1.3 2000/07/15 20:53:23 mdw - * More hash functions. Bug fix in getstring. - * - * Revision 1.2 2000/07/01 11:27:22 mdw - * Use new PKCS#1 padding functions rather than rolling by hand. - * - * Revision 1.1 2000/06/17 10:54:29 mdw - * Program to generate and verify signatures on multiple files. - * - */ - /*----- Header files ------------------------------------------------------*/ #include "config.h" @@ -73,201 +45,12 @@ #include #include "getdate.h" -#include "grand.h" +#include "rand.h" #include "ghash.h" #include "key.h" #include "key-data.h" #include "noise.h" - -#include "dsa.h" -#include "rsa.h" -#include "pkcs1.h" - -#include "md2.h" -#include "md4.h" -#include "md5.h" -#include "rmd128.h" -#include "rmd160.h" -#include "rmd256.h" -#include "rmd320.h" -#include "sha.h" -#include "sha256.h" -#include "sha384.h" -#include "sha512.h" -#include "tiger.h" - -/*----- Digital signature algorithm ---------------------------------------*/ - -static int dsasign(key *k, const void *m, size_t msz, dstr *d) -{ - dsa_priv dp; - key_packstruct ks[DSA_PRIVFETCHSZ]; - key_packdef *kp; - size_t sz; - octet *p; - int e; - - kp = key_fetchinit(dsa_privfetch, ks, &dp); - if ((e = key_fetch(kp, k)) != 0) { - key_fetchdone(kp); - return (e); - } - sz = mp_octets(dp.dp.q); - if (sz < msz) - die(EXIT_FAILURE, "hash function too wide for this signing key"); - DENSURE(d, sz * 2); - p = (octet *)d->buf + d->len; - rand_get(RAND_GLOBAL, p, sz); - dsa_sign(&dp.dp, dp.x, m, msz, p, sz, p, sz, p + sz, sz); - d->len += sz * 2; - key_fetchdone(kp); - return (0); -} - -static int dsaverify(key *k, const void *m, size_t msz, - const void *s, size_t ssz) -{ - dsa_pub dp; - key_packstruct ks[DSA_PUBFETCHSZ]; - key_packdef *kp; - size_t sz; - const octet *p = s; - int e; - - kp = key_fetchinit(dsa_pubfetch, ks, &dp); - if ((e = key_fetch(kp, k)) != 0) { - key_fetchdone(kp); - return (e); - } - sz = ssz / 2; - e = dsa_verify(&dp.dp, dp.y, m, msz, p, sz, p + sz, sz); - key_fetchdone(kp); - return (e); -} - -/*----- RSA signing -------------------------------------------------------*/ - -static int rsasign(key *k, const void *m, size_t msz, dstr *d) -{ - rsa_priv rp; - rsa_privctx rpc; - pkcs1 pk = { 0, 0, 0 }; - key_packstruct ks[RSA_PRIVFETCHSZ]; - key_packdef *kp; - int e; - - kp = key_fetchinit(rsa_privfetch, ks, &rp); - if ((e = key_fetch(kp, k)) != 0) { - key_fetchdone(kp); - return (e); - } - rsa_privcreate(&rpc, &rp, &rand_global); - if (rsa_sign(&rpc, m, msz, d, pkcs1_sigencode, &pk) < 0) - die(EXIT_FAILURE, "internal error in rsasign (key too small?)"); - rsa_privdestroy(&rpc); - key_fetchdone(kp); - return (0); -} - -static int rsaverify(key *k, const void *m, size_t msz, - const void *s, size_t ssz) -{ - rsa_pub rp; - rsa_pubctx rpc; - pkcs1 pk = { 0, 0, 0 }; - key_packstruct ks[RSA_PUBFETCHSZ]; - key_packdef *kp; - int ok = 0; - dstr d = DSTR_INIT; - int e; - - kp = key_fetchinit(rsa_pubfetch, ks, &rp); - if ((e = key_fetch(kp, k)) != 0) { - key_fetchdone(kp); - return (e); - } - rsa_pubcreate(&rpc, &rp); - if (rsa_verify(&rpc, s, ssz, &d, pkcs1_sigdecode, &pk) > 0 && - msz == d.len && memcmp(d.buf, m, msz) == 0) - ok = 1; - dstr_destroy(&d); - rsa_pubdestroy(&rpc); - key_fetchdone(kp); - return (ok); -} - -/*----- Algorithm choice --------------------------------------------------*/ - -typedef struct sig { - const char *name; - const char *type; - int (*sign)(key */*k*/, const void */*m*/, size_t /*msz*/, dstr */*d*/); - int (*verify)(key */*k*/, const void */*m*/, size_t /*msz*/, - const void */*s*/, size_t /*ssz*/); -} sig; - -static const gchash *hashtab[] = { - &rmd160, &tiger, &sha, &sha256, &sha384, &sha512, - &rmd128, &rmd256, &rmd320, &md5, &md4, &md2, 0 }; -static sig sigtab[] = { - { "dsa", "dsig-dsa", dsasign, dsaverify }, - { "rsa", "dsig-rsa", rsasign, rsaverify }, - { 0, 0, 0 } -}; - -/* --- @gethash@ --- * - * - * Arguments: @const char *name@ = pointer to name string - * - * Returns: Pointer to appropriate hash class. - * - * Use: Chooses a hash function by name. - */ - -static const gchash *gethash(const char *name) -{ - const gchash **g, *gg = 0; - size_t sz = strlen(name); - for (g = hashtab; *g; g++) { - if (strncmp(name, (*g)->name, sz) == 0) { - if ((*g)->name[sz] == 0) { - gg = *g; - break; - } else if (gg) - return (0); - else - gg = *g; - } - } - return (gg); -} - -/* --- @getsig@ --- * - * - * Arguments: @const char *name@ = pointer to name string - * - * Returns: Pointer to appropriate signature type. - * - * Use: Chooses a signature algorithm by name. - */ - -static sig *getsig(const char *name) -{ - sig *s, *ss = 0; - size_t sz = strlen(name); - for (s = sigtab; s->name; s++) { - if (strncmp(name, s->name, sz) == 0) { - if (s->name[sz] == 0) { - ss = s; - break; - } else if (ss) - return (0); - else - ss = s; - } - } - return (ss); -} +#include "cc.h" /*----- Data formatting ---------------------------------------------------*/ @@ -282,8 +65,6 @@ enum { /* --- Block tags --- */ T_IDENT = 0, /* An identifying marker */ - T_SIGALG, /* Signature algorithm used */ - T_HASHALG, /* Hash algorithm used */ T_KEYID, /* Key identifier */ T_BEGIN, /* Begin hashing here */ T_COMMENT = T_BEGIN, /* A textual comment */ @@ -303,7 +84,7 @@ enum { /* --- Name translation table --- */ static const char *tagtab[] = { - "ident:", "sigalg:", "hashalg:", "keyid:", + "ident:", "keyid:", "comment:", "date:", "expires:", "file:", "signature:", 0 @@ -605,8 +386,6 @@ static int bget(block *b, FILE *fp, unsigned bin) case T_IDENT: case T_COMMENT: - case T_SIGALG: - case T_HASHALG: if (getstring(fp, &b->d, bin)) return (E_EOF); break; @@ -699,8 +478,6 @@ static void blob(block *b, dstr *d) DPUTC(d, b->tag); switch (b->tag) { case T_IDENT: - case T_SIGALG: - case T_HASHALG: case T_COMMENT: DPUTD(d, &b->d); DPUTC(d, 0); @@ -747,8 +524,6 @@ static void bwrite(block *b, FILE *fp) putc(' ', fp); switch (b->tag) { case T_IDENT: - case T_SIGALG: - case T_HASHALG: case T_COMMENT: putstring(fp, b->d.buf, 0); break; @@ -798,7 +573,7 @@ static void bemit(block *b, FILE *fp, ghash *h, unsigned bin) dstr d = DSTR_INIT; blob(b, &d); if (h) - h->ops->hash(h, d.buf, d.len); + GH_HASH(h, d.buf, d.len); if (fp && bin) fwrite(d.buf, d.len, 1, fp); } @@ -843,7 +618,7 @@ static void keyreport(const char *file, int line, const char *err, void *p) static int fhash(const gchash *c, const char *file, void *b) { FILE *fp = fopen(file, "rb"); - ghash *h = c->init(); + ghash *h = GH_INIT(c); char buf[4096]; size_t sz; int rc = 0; @@ -851,11 +626,11 @@ static int fhash(const gchash *c, const char *file, void *b) if (!fp) return (-1); while ((sz = fread(buf, 1, sizeof(buf), fp)) > 0) - h->ops->hash(h, buf, sz); + GH_HASH(h, buf, sz); if (ferror(fp)) rc = -1; - h->ops->done(h, b); - h->ops->destroy(h); + GH_DONE(h, b); + GH_DESTROY(h); fclose(fp); return (rc); } @@ -881,7 +656,6 @@ static void fhex(FILE *fp, const void *p, size_t sz) sz--; if (!sz) break; -/* putc(' ', fp); */ } } @@ -894,18 +668,16 @@ static int sign(int argc, char *argv[]) #define f_bogus 4u unsigned f = 0; - const char *kt = 0; - const char *ki = 0; + const char *ki = "dsig"; key_file kf; key *k; - const sig *s = sigtab; - const gchash *gch = &rmd160; - ghash *h; + sig *s; time_t exp = KEXP_EXPIRE; unsigned verb = 0; const char *ifile = 0; const char *ofile = 0; const char *c = 0; + const char *err; FILE *ifp, *ofp; dstr d = DSTR_INIT; block b; @@ -917,18 +689,14 @@ static int sign(int argc, char *argv[]) { "binary", 0, 0, 'b' }, { "verbose", 0, 0, 'v' }, { "quiet", 0, 0, 'q' }, - { "algorithm", OPTF_ARGREQ, 0, 'a' }, - { "hash", OPTF_ARGREQ, 0, 'h' }, { "comment", OPTF_ARGREQ, 0, 'c' }, { "file", OPTF_ARGREQ, 0, 'f' }, { "output", OPTF_ARGREQ, 0, 'o' }, - { "keytype", OPTF_ARGREQ, 0, 't' }, - { "keyid", OPTF_ARGREQ, 0, 'i' }, - { "key", OPTF_ARGREQ, 0, 'i' }, + { "key", OPTF_ARGREQ, 0, 'k' }, { "expire", OPTF_ARGREQ, 0, 'e' }, { 0, 0, 0, 0 } }; - int i = mdwopt(argc, argv, "+0vqb a:h:c: f:o: t:i:k:e:", opts, 0, 0, 0); + int i = mdwopt(argc, argv, "+0vqb" "c:" "f:o:" "k:e:", opts, 0, 0, 0); if (i < 0) break; switch (i) { @@ -945,18 +713,6 @@ static int sign(int argc, char *argv[]) if (verb > 0) verb--; break; - case 'a': - if ((s = getsig(optarg)) == 0) { - die(EXIT_FAILURE, "unknown or ambiguous signature algorithm `%s'", - optarg); - } - break; - case 'h': - if ((gch = gethash(optarg)) == 0) { - die(EXIT_FAILURE, "unknown or ambiguous hash function `%s'", - optarg); - } - break; case 'c': c = optarg; break; @@ -966,10 +722,6 @@ static int sign(int argc, char *argv[]) case 'o': ofile = optarg; break; - case 't': - kt = optarg; - break; - case 'i': case 'k': ki = optarg; break; @@ -991,20 +743,19 @@ static int sign(int argc, char *argv[]) if (key_open(&kf, keyring, KOPEN_WRITE, keyreport, 0)) die(EXIT_FAILURE, "couldn't open keyring `%s'", keyring); - if (ki) { - if ((k = key_bytag(&kf, ki)) == 0) - die(EXIT_FAILURE, "couldn't find key `%s'", ki); - } else { - if (!kt) - kt = s->type; - if ((k = key_bytype(&kf, kt)) == 0) - die(EXIT_FAILURE, "no appropriate key of type `%s'", kt); - } + if ((k = key_bytag(&kf, ki)) == 0) + die(EXIT_FAILURE, "couldn't find key `%s'", ki); key_fulltag(k, &d); if (exp == KEXP_FOREVER && k->exp != KEXP_FOREVER) { die(EXIT_FAILURE, "key `%s' expires: can't create nonexpiring signature", d.buf); } + s = getsig(k, "dsig", 1); + + /* --- Check the key --- */ + + if ((err = s->ops->check(s)) != 0) + moan("key `%s' fails check: %s", d.buf, err); /* --- Open files --- */ @@ -1022,35 +773,27 @@ static int sign(int argc, char *argv[]) ofile, strerror(errno)); } - h = gch->init(); - /* --- Emit the start of the output --- */ binit(&b); b.tag = T_IDENT; dstr_putf(&b.d, "%s, Catacomb version " VERSION, QUIS); bemit(&b, ofp, 0, f & f_bin); - breset(&b); b.tag = T_SIGALG; DPUTS(&b.d, s->name); - bemit(&b, ofp, h, f & f_bin); - - breset(&b); b.tag = T_HASHALG; DPUTS(&b.d, gch->name); - bemit(&b, ofp, h, f & f_bin); - breset(&b); b.tag = T_KEYID; b.k = k->id; - bemit(&b, ofp, h, f & f_bin); + bemit(&b, ofp, 0, f & f_bin); /* --- Start hashing, and emit the datestamps and things --- */ { time_t now = time(0); - breset(&b); b.tag = T_DATE; b.t = now; bemit(&b, ofp, h, f & f_bin); + breset(&b); b.tag = T_DATE; b.t = now; bemit(&b, ofp, s->h, f & f_bin); if (exp == KEXP_EXPIRE) exp = now + 86400 * 28; - breset(&b); b.tag = T_EXPIRE; b.t = exp; bemit(&b, ofp, h, f & f_bin); + breset(&b); b.tag = T_EXPIRE; b.t = exp; bemit(&b, ofp, s->h, f & f_bin); if (c) { breset(&b); b.tag = T_COMMENT; DPUTS(&b.d, c); - bemit(&b, ofp, h, f & f_bin); + bemit(&b, ofp, s->h, f & f_bin); } if (!(f & f_bin)) @@ -1074,17 +817,17 @@ static int sign(int argc, char *argv[]) if (getstring(ifp, &b.d, f & f_raw)) break; b.tag = T_FILE; - DENSURE(&b.b, h->ops->c->hashsz); - if (fhash(gch, b.d.buf, b.b.buf)) { + DENSURE(&b.b, GH_CLASS(s->h)->hashsz); + if (fhash(GH_CLASS(s->h), b.d.buf, b.b.buf)) { moan("Error reading `%s': %s", b.d.buf, strerror(errno)); f |= f_bogus; } else { - b.b.len += h->ops->c->hashsz; + b.b.len += GH_CLASS(s->h)->hashsz; if (verb) { fhex(stderr, b.b.buf, b.b.len); fprintf(stderr, " %s\n", b.d.buf); } - bemit(&b, ofp, h, f & f_bin); + bemit(&b, ofp, s->h, f & f_bin); } } @@ -1093,9 +836,7 @@ static int sign(int argc, char *argv[]) if (!(f & f_bogus)) { breset(&b); b.tag = T_SIGNATURE; - DENSURE(&b.d, h->ops->c->hashsz); - h->ops->done(h, b.d.buf); - if ((e = s->sign(k, b.d.buf, h->ops->c->hashsz, &b.b)) != 0) { + if ((e = s->ops->doit(s, &b.b)) != 0) { moan("error creating signature: %s", key_strerror(e)); f |= f_bogus; } @@ -1107,6 +848,7 @@ static int sign(int argc, char *argv[]) /* --- Tidy up at the end --- */ + freesig(s); bdestroy(&b); if (ifile) fclose(ifp); @@ -1148,10 +890,9 @@ static int verify(int argc, char *argv[]) unsigned verb = 1; key_file kf; key *k = 0; - sig *s = sigtab; - const gchash *gch = &rmd160; + sig *s; dstr d = DSTR_INIT; - ghash *h = 0; + const char *err; FILE *fp; block b; int e; @@ -1211,11 +952,11 @@ static int verify(int argc, char *argv[]) /* --- Read the introductory matter --- */ binit(&b); - for (;;) { + for (;;) { breset(&b); e = bget(&b, fp, f & f_bin); if (e < 0) - die(EXIT_FAILURE, "error reading packet: %s\n", errtab[-e]); + die(EXIT_FAILURE, "error reading packet: %s", errtab[-e]); if (e >= T_BEGIN) break; switch (e) { @@ -1223,24 +964,6 @@ static int verify(int argc, char *argv[]) if (verb > 2) printf("INFO ident: `%s'\n", b.d.buf); break; - case T_SIGALG: - if ((s = getsig(b.d.buf)) == 0) { - if (verb) - printf("FAIL unknown signature algorithm `%s'\n", b.d.buf); - exit(EXIT_FAILURE); - } - if (verb > 2) - printf("INFO signature algorithm: %s\n", s->name); - break; - case T_HASHALG: - if ((gch = gethash(b.d.buf)) == 0) { - if (verb) - printf("FAIL unknown hash function `%s'\n", b.d.buf); - exit(EXIT_FAILURE); - } - if (verb > 2) - printf("INFO hash function algorithm: %s\n", gch->name); - break; case T_KEYID: if ((k = key_byid(&kf, b.k)) == 0) { if (verb) @@ -1261,32 +984,22 @@ static int verify(int argc, char *argv[]) /* --- Initialize the hash function and start reading hashed packets --- */ - h = gch->init(); - if (!k) { if (verb) puts("FAIL no keyid packet found"); exit(EXIT_FAILURE); } - { - block bb; - binit(&bb); - breset(&bb); bb.tag = T_SIGALG; DPUTS(&bb.d, s->name); - bemit(&bb, 0, h, 0); - breset(&bb); bb.tag = T_HASHALG; DPUTS(&bb.d, gch->name); - bemit(&bb, 0, h, 0); - breset(&bb); bb.tag = T_KEYID; bb.k = k->id; - bemit(&bb, 0, h, 0); - bdestroy(&bb); - } + s = getsig(k, "dsig", 0); + if (verb && (err = s->ops->check(s)) != 0) + printf("WARN public key fails check: %s", err); for (;;) { switch (e) { case T_COMMENT: if (verb > 1) printf("INFO comment: `%s'\n", b.d.buf); - bemit(&b, 0, h, 0); + bemit(&b, 0, s->h, 0); break; case T_DATE: if (verb > 2) { @@ -1294,7 +1007,7 @@ static int verify(int argc, char *argv[]) timestring(b.t, &b.d); printf("INFO date: %s\n", b.d.buf); } - bemit(&b, 0, h, 0); + bemit(&b, 0, s->h, 0); break; case T_EXPIRE: { time_t now = time(0); @@ -1308,18 +1021,18 @@ static int verify(int argc, char *argv[]) timestring(b.t, &b.d); printf("INFO expires: %s\n", b.d.buf); } - bemit(&b, 0, h, 0); + bemit(&b, 0, s->h, 0); } break; case T_FILE: DRESET(&d); - DENSURE(&d, gch->hashsz); - if (fhash(gch, b.d.buf, d.buf)) { + DENSURE(&d, GH_CLASS(s->h)->hashsz); + if (fhash(GH_CLASS(s->h), b.d.buf, d.buf)) { if (verb > 1) { printf("BAD error reading file `%s': %s\n", b.d.buf, strerror(errno)); } f |= f_bogus; - } else if (b.b.len != gch->hashsz || + } else if (b.b.len != GH_CLASS(s->h)->hashsz || memcmp(d.buf, b.b.buf, b.b.len) != 0) { if (verb > 1) printf("BAD file `%s' has incorrect hash\n", b.d.buf); @@ -1329,21 +1042,12 @@ static int verify(int argc, char *argv[]) fhex(stdout, b.b.buf, b.b.len); printf(" %s\n", b.d.buf); } - bemit(&b, 0, h, 0); + bemit(&b, 0, s->h, 0); break; case T_SIGNATURE: - DRESET(&b.d); - DENSURE(&b.d, h->ops->c->hashsz); - b.d.len += h->ops->c->hashsz; - h->ops->done(h, b.d.buf); - e = s->verify(k, b.d.buf, b.d.len, b.b.buf, b.b.len); - if (e != 1) { - if (verb > 1) { - if (e < 0) { - printf("BAD error unpacking key: %s\n", key_strerror(e)); - } else - puts("BAD bad signature"); - } + if (s->ops->doit(s, &b.b)) { + if (verb > 1) + puts("BAD bad signature"); f |= f_bogus; } else if (verb > 2) puts("INFO good signature"); @@ -1365,6 +1069,7 @@ static int verify(int argc, char *argv[]) done: bdestroy(&b); dstr_destroy(&d); + freesig(s); key_close(&kf); if (fp != stdin) fclose(fp); @@ -1391,25 +1096,19 @@ typedef struct cmd { } cmd; static cmd cmdtab[] = { -/* { "manifest", manifest, */ -/* "manifest [-0] [-o output]" }, */ { "sign", sign, - "sign [-options]\n\ - [-0bqv] [-a alg] [-h hash] [-t keytype] [-i keyid]\n\ - [-e expire] [-f file] [-o output]", "\ + "sign [-0bqv] [-c comment] [-k tag] [-e expire] [-f file] [-o output]", + "\ Options:\n\ \n\ -0, --null Read null-terminated filenames from stdin.\n\ -b, --binary Produce a binary output file.\n\ -q, --quiet Produce fewer messages while working.\n\ -v, --verbose Produce more messages while working.\n\ --a, --algorithm=SIGALG Use the SIGALG signature algorithm.\n\ --h, --hash=HASHASL Use the HASHALG message digest algorithm.\n\ -c, --comment=COMMENT Include COMMENT in the output file.\n\ -f, --file=FILE Read filenames to hash from FILE.\n\ -o, --output=FILE Write the signed result to FILE.\n\ --t, --keytype=TYPE Use a key with type TYPE to do the signing.\n\ --i, --keyid=ID Use the key with the given ID to do the signing.\n\ +-k, --key=TAG Use a key named by TAG.\n\ -e, --expire=TIME The signature should expire after TIME.\n\ " }, { "verify", verify,