/* -*-c-*-
*
- * $Id: keyutil.c,v 1.16 2003/10/15 09:31:45 mdw Exp $
+ * $Id: keyutil.c,v 1.17 2004/03/28 01:58:47 mdw Exp $
*
* Simple key manager program
*
/*----- Revision history --------------------------------------------------*
*
* $Log: keyutil.c,v $
+ * Revision 1.17 2004/03/28 01:58:47 mdw
+ * Generate, store and retreive elliptic curve keys.
+ *
* Revision 1.16 2003/10/15 09:31:45 mdw
* Fix help message.
*
#include "bbs.h"
#include "dh.h"
#include "dsa.h"
+#include "ec.h"
+#include "ec-keys.h"
+#include "ectab.h"
#include "fibrand.h"
#include "getdate.h"
#include "key.h"
dstr tag; /* Full tag name for the key */
unsigned f; /* Flags for the new key */
unsigned bits, qbits; /* Bit length for the new key */
+ const char *curve; /* Elliptic curve name/info */
key *p; /* Parameters key-data */
} keyopts;
int i;
if (!k->bits)
- k->bits = 112;
+ k->bits = 168;
if (k->p)
die(EXIT_FAILURE, "no shared parameters for DES keys");
if (k->bits % 56 || k->bits > 168)
bbs_privfree(&bp);
}
+static void alg_ecparam(keyopts *k)
+{
+ static const char *pl[] = { "curve", 0 };
+ if (!copyparam(k, pl)) {
+ ec_info ei;
+ const char *e;
+ key_data *kd = &k->k->k;
+
+ /* --- Decide on a curve --- */
+
+ if (!k->bits) k->bits = 256;
+ if (!k->curve) {
+ if (k->bits <= 56) k->curve = "secp112r1";
+ else if (k->bits <= 64) k->curve = "secp128r1";
+ else if (k->bits <= 80) k->curve = "secp160r1";
+ else if (k->bits <= 96) k->curve = "secp192r1";
+ else if (k->bits <= 112) k->curve = "secp224r1";
+ else if (k->bits <= 128) k->curve = "secp256r1";
+ else if (k->bits <= 192) k->curve = "secp384r1";
+ else if (k->bits <= 256) k->curve = "secp521r1";
+ else
+ die(EXIT_FAILURE, "no built-in curves provide %u-bit security",
+ k->bits);
+ }
+
+ /* --- Check it --- */
+
+ if ((e = ec_getinfo(&ei, k->curve)) != 0)
+ die(EXIT_FAILURE, "error in curve spec: %s", e);
+ if (!(k->f & f_quiet) && (e = ec_checkinfo(&ei, &rand_global)) != 0)
+ moan("WARNING! curve check failed: %s", e);
+ ec_freeinfo(&ei);
+
+ /* --- Write out the answer --- */
+
+ key_structure(kd);
+ kd = key_structcreate(kd, "curve");
+ key_string(kd, k->curve);
+ kd->e |= KCAT_SHARE;
+ }
+}
+
+static void alg_ec(keyopts *k)
+{
+ key_data *kd = &k->k->k;
+ key_data *kkd;
+ mp *x = MP_NEW;
+ ec p = EC_INIT;
+ const char *e;
+ ec_info ei;
+
+ /* --- Get the curve --- */
+
+ alg_ecparam(k);
+ if ((kkd = key_structfind(kd, "curve")) == 0)
+ die(EXIT_FAILURE, "unexpected failure looking up subkey `curve')");
+ if ((kkd->e & KF_ENCMASK) != KENC_STRING)
+ die(EXIT_FAILURE, "subkey `curve' is not a string");
+ if ((e = ec_getinfo(&ei, kkd->u.p)) != 0)
+ die(EXIT_FAILURE, "error in curve spec: %s", e);
+
+ /* --- Invent a private exponent and compute the public key --- */
+
+ x = mprand_range(MP_NEWSEC, ei.r, &rand_global, 0);
+ ec_mul(ei.c, &p, &ei.g, x);
+
+ /* --- Store everything away --- */
+
+ kkd = key_structcreate(kd, "p");
+ key_ec(kkd, &p);
+ kkd->e |= KCAT_PUB;
+ kkd = key_structcreate(kd, "private");
+ key_structure(kkd);
+ mpkey(kkd, "x", x, KCAT_PRIV | KF_BURN);
+
+ /* --- Done --- */
+
+ ec_freeinfo(&ei);
+ mp_drop(x);
+}
+
/* --- The algorithm tables --- */
typedef struct keyalg {
{ "dh", alg_dh, "Diffie-Hellman key exchange" },
{ "dh-param", alg_dhparam, "Diffie-Hellman parameters" },
{ "bbs", alg_bbs, "Blum-Blum-Shub generator" },
+ { "ec-param", alg_ecparam, "Elliptic curve parameters" },
+ { "ec", alg_ec, "Elliptic curve crypto" },
{ 0, 0 }
};
{ "comment", OPTF_ARGREQ, 0, 'c' },
{ "tag", OPTF_ARGREQ, 0, 't' },
{ "rand-id", OPTF_ARGREQ, 0, 'R' },
+ { "curve", OPTF_ARGREQ, 0, 'C' },
{ "lock", 0, 0, 'l' },
{ "quiet", 0, 0, 'q' },
{ "lim-lee", 0, 0, 'L' },
{ "subgroup", 0, 0, 'S' },
{ 0, 0, 0, 0 }
};
- int i = mdwopt(argc, argv, "+a:b:B:p:e:c:t:R:lqrLS", opt, 0, 0, 0);
+ int i = mdwopt(argc, argv, "+a:b:B:p:e:c:t:R:C:lqrLS", opt, 0, 0, 0);
if (i < 0)
break;
c = optarg;
break;
+ /* --- Elliptic curve parameters --- */
+
+ case 'C':
+ if (strcmp(optarg, "list") == 0) {
+ const ecentry *ee;
+ printf("Built-in elliptic curves:\n");
+ for (ee = ectab; ee->name; ee++)
+ printf(" %s\n", ee->name);
+ exit(0);
+ }
+ k.curve = optarg;
+ break;
+
/* --- Store tags --- */
case 't':
putchar('\n');
break;
+ /* --- Strings --- */
+
+ case KENC_STRING:
+ printf(" `%s'\n", k->u.p);
+ break;
+
+ /* --- Elliptic curve points --- */
+
+ case KENC_EC:
+ fputs(" 0x", stdout); mp_writefile(k->u.e.x, stdout, 16);
+ fputs(", 0x", stdout); mp_writefile(k->u.e.y, stdout, 16);
+ putchar('\n');
+ break;
+
/* --- Structured keys --- *
*
* Just iterate over the subkeys.
-b, --bits=N Generate an N-bit key.\n\
-B, --qbits=N Use an N-bit subgroup or factors.\n\
-p, --parameters=TAG Get group parameters from TAG.\n\
+-C, --curve=CURVE Use elliptic curve CURVE.\n\
-e, --expire=TIME Make the key expire after TIME.\n\
-c, --comment=STRING Attach the command STRING to the key.\n\
-t, --tag=TAG Tag the key with the name TAG.\n\
projects / u / mdw / catacomb / blobdiff