tomcrypt/dh.c
2010-06-16 12:37:55 +02:00

485 lines
13 KiB
C

#include "mycrypt.h"
#ifdef MDH
/* This holds the key settings. ***MUST*** be organized by size from smallest to largest. */
static const struct {
int size;
char *name, *base, *prime;
} sets[] = {
#ifdef DH768
{
96,
"DH-768",
"2",
"1tH+dRFGpEYyVLe4ydZcYyGDpeAxnChz0yk+pNCtkEXwUsOORyguBtx8spUD"
"FAjEDS8PutUBTEu2q4USqu19dUbCLj9D2jY7y3871RnSccurMBsMm35ILcyQ"
"rpN0MQKc/"
},
#endif
#ifdef DH1024
{
128,
"DH-1024",
"2",
"Uypu+t9nfUnCj7xD+xokM+Cd6mASW4ofg1jpC2BpQasC5edtA1dJC+RjbOBZ"
"z+5mvq5VYT8Wfjmlpjm9tQxHOYB0+3Myl7gbCQ5SRljWT2oBLukLNvgFjiU4"
"wiWkmu41Ern/j6uxwKb740C+VIgDAdeUY4fA5hyfr3/+DWYb14/"
},
#endif
#ifdef DH1280
{
160,
"DH-1280",
"2",
"520QV4Tsq4NwK9Mt5CGR9xk4slvaikgi/ax3OPky5GERKTsoqEXOlFyMzURP"
"P8jYzCVz1izKd2zTDxbFfLxrJry0ceaQ5YZa5N4teByCPVlQh4v6iQl+944+"
"/NDlKzvWpx7HG7k8cGKhva7aFF8bP/CvLpaQhrfXlOX+X9pcmML9QH63tUjq"
"B80l8Yx9KN0dC3iNnsTV3DnqnEvFQkoqql"
},
#endif
#ifdef DH1536
{
192,
"DH-1536",
"3",
"1FTWXrPcY1w74oZ0ouIzSN8uZcRiOf6U11fx0ka6+7fqIAezPhd3Ab43QnDf"
"KFg+or/fFRGEWAxF8WIE2jx8iTOu010yNEQyH14CK0RAyy2zY4gRs2MpnU5r"
"/feWf60OkLtnPzN34+Xnlg5xf7Jl00wkHRCeJG17L3SklOidAPxWnE+Wm4BS"
"SOzdQBgiZOjlhrYS1+TIU3NP5H7BrtKFcf+ZwBULibf29L7LkDOgQbie1+43"
"lU+8SHAyBwAeGYMfZ"
},
#endif
#ifdef DH1792
{
224,
"DH-1792",
"2",
"IPo3wjvfS7vBYnFHwJHmesA51od9fnR8Aenezif4qLE2HX+YCv1tpvHA8yLH"
"yYbKe9QfSHHtOgVjK8AYEyPirpXxlmdykGuj+dX7EiWMRGYc+v1kKkqmCn0o"
"5tU416O/1HXTpQ2Hps0buchUD+HlCMrSgnIqRxK6Fjr0ZfiCS4XgAD6sLgi0"
"BxKFMxDsVzpGMNwF5Lj2R/cJiTi0cNDDY3gn4lK/PRUsJtRKU+9sxy0q5Yof"
"aG5VO8VcHkZJVwUKhDFHkZYWMHV808TGHXM2RQ9kRa2QvS2mXxMrDSCloQ/"
},
#endif
#ifdef DH2048
{
256,
"DH-2048",
"2",
"5sR1VmdsQQzzjN0iridVVyveug6sAC3+/jTIHSgEoimPOREXQ05r2WJZJAF2"
"CRu8kuusiPw2ivRli+fdLr63v1uZG5nQa28uLwNxZEsu4gu6TrGjepXeXm4Z"
"CVOC1HMmi660fLZ2ruHLa4v2NWex2Zx91/y4ygPlZM+K//iy+Gft9Ma9Ayn0"
"eYwofZeUL9vJSfutPVp2ZrIEUQDBKMvMm0SRSLiUjDtzXqrH+b/wuwIFG1K4"
"var3ucsT45mDzD9qb3tBdksSPZbr6yrELV8h+qmjiBr15oHKEglS0XwSvCap"
"abUn5XPPVoaKv13+tOnG9mGgzQ8JeClVXN63Q+GGEF"
},
#endif
#ifdef DH2560
{
320,
"DH-2560",
"3",
"G7UVKk+N6LfpGkdBP6XLB4QJ3wzee5YH/3o6tBDMwr4FS8YjCmeP6l4gu0hX"
"dzY2Rive4TYOu4Akm4naZuv32d71/2lQeNcO23BNYOEPxtn9BU8uYfaHP9Mo"
"M+m76oUCiI5uqpag5RH3BO34FyE4BiKkzjEXq9xxc8ERacG8Mo8DNiXu79p9"
"Q/0wsRz+W/lIN4gYw3w4iLMooAGnDrhcj5cZb0HysHWYfqmFo+jTBP6Egi0g"
"cmVO2qWQh2cZIQMfppaf1Ffq0XGIJpgDFyOHPl3NVxDabVK1tkVct+hathxJ"
"UTdqZmR2VFwMASXjfgj4VFdvFCUxV8Xr8JcwXkwlMjOJbAl0LoCa4M7hpYvz"
"G/0XviGCpv7qQaONKtsiQ6mHhMcyo9hBCRZXtNPkfPMZkPeV05akvaDs6Ek7"
"DZ62oKR"
},
#endif
#ifdef DH3072
{
384,
"DH-3072",
"2",
"1zsV6XgY57R/hu2RR4H/BjwRqmQL9h+Dc5rgoWOcqiTS8qpVTWafi1KFV77V"
"rUcjcer1EDgCV0tpzlemtyrC2pHpw7hr3EEl2evfWOvg05FRI6mKc2UPNv2c"
"2Bjww4LD/tdsLleX7AHHXCXFSSyd6C3qWq7BqABZriSpQeaEtXbWfeC6ytFe"
"2i3VeQsLa40XQ21UxwhPAjamjSOfYzkW7xi0fwI1e+4OQiFcWOfOuvswoaEf"
"MIICyAmVp67vjGo66dk81dMemyplipgXAWPdl7ppnDd6cEjyN4N90D7kQiNg"
"lVmJlKLecldOUtdIqMnbJCbiN/t/3/AEFaokGO9om5ckc6M9gG5PG0T7Oh1N"
"dSx/PstGdxwvs9DOwjyo5wl5C9QSLtUYJl2+GZYMj6WfsgCrb6jjRJJJQe2C"
"y7wUcBILbRsP3lYT8s14zm4xFBrfMUoLN287j3wQ1TNUXjYSCi4ZLKT1XDai"
"93345OiutLOqGGikFg6ypnymJK3yeHuul"
},
#endif
#ifdef DH4096
{
512,
"DH-4096",
"3",
"Id8ukxZdao3hS0NGTKAXdt3c8PpiyigIyBY8lwOHjM2cqkaZgwvr1pA6OowS"
"32kJkeOqKB8gNTZZZVqOFkPXgvC4WveUgA5a7rhTj28pDidNROmMO70CCcSw"
"aHI3GLFuEMz3JJyvQKGaGwpV3C9gS70dFWTxEfNRzdYEdvIic8/SXI79VgNP"
"LGR68nzd4qxCgaLpVBnWsanRp7mfEj52S/7Kxjs14lrbAOMjCuHgN4F6THWh"
"PNhG0VXfFFIwAMW2unrfpdo+gQHNclqCf2N1FALpABzvUesgs3wIP+QTMqms"
"os/AkuulG7MusbeFl3SoCtaoW12CF038ZbqW+e+DKI1zObhtsLanvaiZm/N4"
"BsJirW7avcWNQYm1oYjZ2bR/jYqfoJ0CLXLO/vqHb8J9a5VE9nz7cqMD3/MH"
"k/g7BapsOtKuol6ipbUvxQPtf4KCwqQQ40JeqgS6amivI/aLu05S7bAxKOwE"
"Yu8YxjN6lXm3co5Wy+BmNSuRlzKhxICyHEqMfKwUtm48XHzHuPaGQzHgkn6H"
"3A+FQjQGLHewADYlbfdTF3sHYyc5k9h/9cYVkbmv7bQze53CJGr3T1hZYbN6"
"+fuz0SPnfjiKu+bWD+8RYtZpLs2+f32huMz3OqoryGfULxC2aEjL2rdBn+ZR"
"PT0+ZAUyLSAVHbsul++cawh"
},
#endif
{
0,
NULL,
NULL,
NULL
}
};
static int is_valid_idx(int n)
{
int x;
for (x = 0; sets[x].size; x++);
if ((n < 0) || (n >= x)) {
return 0;
}
return 1;
}
int dh_test(void)
{
mp_int p, g, tmp;
int x, res, primality;
if (mp_init_multi(&p, &g, &tmp, NULL) != MP_OKAY) { goto error; }
for (x = 0; sets[x].size != 0; x++) {
#if 0
printf("dh_test():testing size %d-bits\n", sets[x].size * 8);
#endif
if (mp_read_radix(&g,(unsigned char *)sets[x].base, 64) != MP_OKAY) { goto error; }
if (mp_read_radix(&p,(unsigned char *)sets[x].prime, 64) != MP_OKAY) { goto error; }
/* ensure p is prime */
if ((res = is_prime(&p, &primality)) != CRYPT_OK) { goto done; }
if (primality == 0) {
res = CRYPT_FAIL_TESTVECTOR;
goto done;
}
if (mp_sub_d(&p, 1, &tmp) != MP_OKAY) { goto error; }
if (mp_div_2(&tmp, &tmp) != MP_OKAY) { goto error; }
/* ensure (p-1)/2 is prime */
if ((res = is_prime(&tmp, &primality)) != CRYPT_OK) { goto done; }
if (primality == 0) {
res = CRYPT_FAIL_TESTVECTOR;
goto done;
}
/* now see if g^((p-1)/2) mod p is in fact 1 */
if (mp_exptmod(&g, &tmp, &p, &tmp) != MP_OKAY) { goto error; }
if (mp_cmp_d(&tmp, 1)) {
res = CRYPT_FAIL_TESTVECTOR;
goto done;
}
}
res = CRYPT_OK;
goto done;
error:
res = CRYPT_MEM;
done:
mp_clear_multi(&tmp, &g, &p, NULL);
return res;
}
void dh_sizes(int *low, int *high)
{
int x;
_ARGCHK(low != NULL);
_ARGCHK(high != NULL);
*low = INT_MAX;
*high = 0;
for (x = 0; sets[x].size != 0; x++) {
if (*low > sets[x].size) *low = sets[x].size;
if (*high < sets[x].size) *high = sets[x].size;
}
}
int dh_get_size(dh_key *key)
{
_ARGCHK(key != NULL);
if (is_valid_idx(key->idx) == 1) {
return sets[key->idx].size;
} else {
return INT_MAX; /* large value that would cause dh_make_key() to fail */
}
}
int dh_make_key(prng_state *prng, int wprng, int keysize, dh_key *key)
{
unsigned char buf[512];
unsigned long x;
mp_int p, g;
int res, err;
_ARGCHK(key != NULL);
/* good prng? */
if ((err = prng_is_valid(wprng)) != CRYPT_OK) {
return err;
}
/* find key size */
for (x = 0; (keysize > sets[x].size) && (sets[x].size != 0); x++);
#ifdef FAST_PK
keysize = MIN(sets[x].size, 32);
#else
keysize = sets[x].size;
#endif
if (sets[x].size == 0) {
return CRYPT_INVALID_KEYSIZE;
}
key->idx = x;
/* make up random string */
if (prng_descriptor[wprng].read(buf, keysize, prng) != (unsigned long)keysize) {
return CRYPT_ERROR_READPRNG;
}
/* init parameters */
if (mp_init_multi(&g, &p, &key->x, &key->y, NULL) != MP_OKAY) {
return CRYPT_MEM;
}
if (mp_read_radix(&g, sets[key->idx].base, 64) != MP_OKAY) { goto error; }
if (mp_read_radix(&p, sets[key->idx].prime, 64) != MP_OKAY) { goto error; }
/* load the x value */
if (mp_read_unsigned_bin(&key->x, buf, keysize) != MP_OKAY) { goto error; }
if (mp_exptmod(&g, &key->x, &p, &key->y) != MP_OKAY) { goto error; }
key->type = PK_PRIVATE;
if (mp_shrink(&key->x) != MP_OKAY) { goto error; }
if (mp_shrink(&key->y) != MP_OKAY) { goto error; }
/* free up ram */
res = CRYPT_OK;
goto done2;
error:
res = CRYPT_MEM;
mp_clear_multi(&key->x, &key->y, NULL);
done2:
mp_clear_multi(&p, &g, NULL);
zeromem(buf, sizeof(buf));
return res;
}
void dh_free(dh_key *key)
{
_ARGCHK(key != NULL);
mp_clear_multi(&key->x, &key->y, NULL);
}
#define OUTPUT_BIGNUM(num, buf2, y, z) \
{ \
z = (unsigned long)mp_unsigned_bin_size(num); \
STORE32L(z, buf2+y); \
y += 4; \
(void)mp_to_unsigned_bin(num, buf2+y); \
y += z; \
}
#define INPUT_BIGNUM(num, in, x, y) \
{ \
/* load value */ \
if (y + 4 > inlen) { \
err = CRYPT_INVALID_PACKET; \
goto error; \
} \
LOAD32L(x, in+y); \
y += 4; \
\
/* sanity check... */ \
if (x+y > inlen) { \
err = CRYPT_INVALID_PACKET; \
goto error; \
} \
\
/* load it */ \
if (mp_read_unsigned_bin(num, (unsigned char *)in+y, (int)x) != MP_OKAY) {\
err = CRYPT_MEM; \
goto error; \
} \
y += x; \
if (mp_shrink(num) != MP_OKAY) { \
err = CRYPT_MEM; \
goto error; \
} \
}
int dh_export(unsigned char *out, unsigned long *outlen, int type, dh_key *key)
{
unsigned char buf2[1536];
unsigned long y, z;
_ARGCHK(out != NULL);
_ARGCHK(outlen != NULL);
_ARGCHK(key != NULL);
if (type == PK_PRIVATE && key->type != PK_PRIVATE) {
return CRYPT_PK_NOT_PRIVATE;
}
/* header */
y = PACKET_SIZE;
/* header */
buf2[y++] = type;
buf2[y++] = (unsigned char)(sets[key->idx].size / 8);
/* export y */
OUTPUT_BIGNUM(&key->y, buf2, y, z);
if (type == PK_PRIVATE) {
/* export x */
OUTPUT_BIGNUM(&key->x, buf2, y, z);
}
/* check for overflow */
if (*outlen < y) {
#ifdef CLEAN_STACK
zeromem(buf2, sizeof(buf2));
#endif
return CRYPT_BUFFER_OVERFLOW;
}
/* store header */
packet_store_header(buf2, PACKET_SECT_DH, PACKET_SUB_KEY);
/* output it */
*outlen = y;
memcpy(out, buf2, (size_t)y);
/* clear mem */
#ifdef CLEAN_STACK
zeromem(buf2, sizeof(buf2));
#endif
return CRYPT_OK;
}
int dh_import(const unsigned char *in, unsigned long inlen, dh_key *key)
{
unsigned long x, y, s;
int err;
_ARGCHK(in != NULL);
_ARGCHK(key != NULL);
/* check type byte */
if ((err = packet_valid_header((unsigned char *)in, PACKET_SECT_DH, PACKET_SUB_KEY)) != CRYPT_OK) {
return err;
}
if (2+PACKET_SIZE > inlen) {
return CRYPT_INVALID_PACKET;
}
/* init */
if (mp_init_multi(&key->x, &key->y, NULL) != MP_OKAY) {
return CRYPT_MEM;
}
y = PACKET_SIZE;
key->type = (int)in[y++];
s = (unsigned long)in[y++] * 8;
for (x = 0; (s > (unsigned long)sets[x].size) && (sets[x].size != 0); x++);
if (sets[x].size == 0) {
err = CRYPT_INVALID_KEYSIZE;
goto error;
}
key->idx = (int)x;
/* type check both values */
if ((key->type != PK_PUBLIC) && (key->type != PK_PRIVATE)) {
err = CRYPT_PK_TYPE_MISMATCH;
goto error;
}
/* is the key idx valid? */
if (is_valid_idx(key->idx) != 1) {
err = CRYPT_PK_TYPE_MISMATCH;
goto error;
}
/* load public value g^x mod p*/
INPUT_BIGNUM(&key->y, in, x, y);
if (key->type == PK_PRIVATE) {
INPUT_BIGNUM(&key->x, in, x, y);
}
/* eliminate private key if public */
if (key->type == PK_PUBLIC) {
mp_clear(&key->x);
}
return CRYPT_OK;
error:
mp_clear_multi(&key->y, &key->x, NULL);
return err;
}
int dh_shared_secret(dh_key *private_key, dh_key *public_key,
unsigned char *out, unsigned long *outlen)
{
mp_int tmp, p;
unsigned long x;
int res;
_ARGCHK(private_key != NULL);
_ARGCHK(public_key != NULL);
_ARGCHK(out != NULL);
_ARGCHK(outlen != NULL);
/* types valid? */
if (private_key->type != PK_PRIVATE) {
return CRYPT_PK_NOT_PRIVATE;
}
/* same idx? */
if (private_key->idx != public_key->idx) {
return CRYPT_PK_TYPE_MISMATCH;
}
/* compute y^x mod p */
if (mp_init_multi(&tmp, &p, NULL) != MP_OKAY) {
return CRYPT_MEM;
}
if (mp_read_radix(&p, (unsigned char *)sets[private_key->idx].prime, 64) != MP_OKAY) { goto error; }
if (mp_exptmod(&public_key->y, &private_key->x, &p, &tmp) != MP_OKAY) { goto error; }
/* enough space for output? */
x = (unsigned long)mp_unsigned_bin_size(&tmp);
if (*outlen < x) {
res = CRYPT_BUFFER_OVERFLOW;
goto done;
}
(void)mp_to_unsigned_bin(&tmp, out);
*outlen = x;
res = CRYPT_OK;
goto done;
error:
res = CRYPT_MEM;
done:
mp_clear_multi(&p, &tmp, NULL);
return res;
}
#include "dh_sys.c"
#endif