#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <krb5-types.h>
#include <assert.h>
#include <rsa.h>
#include <roken.h>
#ifdef USE_HCRYPTO_IMATH
#include "imath/imath.h"
#include "imath/iprime.h"
static void
BN2mpz(mpz_t *s, const BIGNUM *bn)
{
size_t len;
void *p;
mp_int_init(s);
len = BN_num_bytes(bn);
p = malloc(len);
BN_bn2bin(bn, p);
mp_int_read_unsigned(s, p, len);
free(p);
}
static BIGNUM *
mpz2BN(mpz_t *s)
{
size_t size;
BIGNUM *bn;
void *p;
size = mp_int_unsigned_len(s);
p = malloc(size);
if (p == NULL && size != 0)
return NULL;
mp_int_to_unsigned(s, p, size);
bn = BN_bin2bn(p, size, NULL);
free(p);
return bn;
}
static int random_num(mp_int, size_t);
static void
setup_blind(mp_int n, mp_int b, mp_int bi)
{
mp_int_init(b);
mp_int_init(bi);
random_num(b, mp_int_count_bits(n));
mp_int_mod(b, n, b);
mp_int_invmod(b, n, bi);
}
static void
blind(mp_int in, mp_int b, mp_int e, mp_int n)
{
mpz_t t1;
mp_int_init(&t1);
mp_int_exptmod(b, e, n, &t1);
mp_int_mul(&t1, in, in);
mp_int_mod(in, n, in);
mp_int_clear(&t1);
}
static void
unblind(mp_int out, mp_int bi, mp_int n)
{
mp_int_mul(out, bi, out);
mp_int_mod(out, n, out);
}
static mp_result
rsa_private_calculate(mp_int in, mp_int p, mp_int q,
mp_int dmp1, mp_int dmq1, mp_int iqmp,
mp_int out)
{
mpz_t vp, vq, u;
mp_int_init(&vp); mp_int_init(&vq); mp_int_init(&u);
mp_int_mod(in, p, &u);
mp_int_exptmod(&u, dmp1, p, &vp);
mp_int_mod(in, q, &u);
mp_int_exptmod(&u, dmq1, q, &vq);
mp_int_sub(&vp, &vq, &u);
if (mp_int_compare_zero(&u) < 0)
mp_int_add(&u, p, &u);
mp_int_mul(&u, iqmp, &u);
mp_int_mod(&u, p, &u);
mp_int_mul(&u, q, &u);
mp_int_add(&u, &vq, out);
mp_int_clear(&vp);
mp_int_clear(&vq);
mp_int_clear(&u);
return MP_OK;
}
static int
imath_rsa_public_encrypt(int flen, const unsigned char* from,
unsigned char* to, RSA* rsa, int padding)
{
unsigned char *p, *p0;
mp_result res;
size_t size, padlen;
mpz_t enc, dec, n, e;
if (padding != RSA_PKCS1_PADDING)
return -1;
size = RSA_size(rsa);
if (size < RSA_PKCS1_PADDING_SIZE || size - RSA_PKCS1_PADDING_SIZE < flen)
return -2;
BN2mpz(&n, rsa->n);
BN2mpz(&e, rsa->e);
p = p0 = malloc(size - 1);
if (p0 == NULL) {
mp_int_clear(&e);
mp_int_clear(&n);
return -3;
}
padlen = size - flen - 3;
*p++ = 2;
if (RAND_bytes(p, padlen) != 1) {
mp_int_clear(&e);
mp_int_clear(&n);
free(p0);
return -4;
}
while(padlen) {
if (*p == 0)
*p = 1;
padlen--;
p++;
}
*p++ = 0;
memcpy(p, from, flen);
p += flen;
assert((p - p0) == size - 1);
mp_int_init(&enc);
mp_int_init(&dec);
mp_int_read_unsigned(&dec, p0, size - 1);
free(p0);
res = mp_int_exptmod(&dec, &e, &n, &enc);
mp_int_clear(&dec);
mp_int_clear(&e);
mp_int_clear(&n);
if (res != MP_OK)
return -4;
{
size_t ssize;
ssize = mp_int_unsigned_len(&enc);
assert(size >= ssize);
mp_int_to_unsigned(&enc, to, ssize);
size = ssize;
}
mp_int_clear(&enc);
return size;
}
static int
imath_rsa_public_decrypt(int flen, const unsigned char* from,
unsigned char* to, RSA* rsa, int padding)
{
unsigned char *p;
mp_result res;
size_t size;
mpz_t s, us, n, e;
if (padding != RSA_PKCS1_PADDING)
return -1;
if (flen > RSA_size(rsa))
return -2;
BN2mpz(&n, rsa->n);
BN2mpz(&e, rsa->e);
#if 0
if (mp_int_compare_value(&e, 3) <= 0) {
mp_int_clear(&n);
mp_int_clear(&e);
return -3;
}
#endif
mp_int_init(&s);
mp_int_init(&us);
mp_int_read_unsigned(&s, rk_UNCONST(from), flen);
if (mp_int_compare(&s, &n) >= 0) {
mp_int_clear(&n);
mp_int_clear(&e);
return -4;
}
res = mp_int_exptmod(&s, &e, &n, &us);
mp_int_clear(&s);
mp_int_clear(&n);
mp_int_clear(&e);
if (res != MP_OK)
return -5;
p = to;
size = mp_int_unsigned_len(&us);
assert(size <= RSA_size(rsa));
mp_int_to_unsigned(&us, p, size);
mp_int_clear(&us);
if (*p == 0)
return -6;
if (*p != 1)
return -7;
size--; p++;
while (size && *p == 0xff) {
size--; p++;
}
if (size == 0 || *p != 0)
return -8;
size--; p++;
memmove(to, p, size);
return size;
}
static int
imath_rsa_private_encrypt(int flen, const unsigned char* from,
unsigned char* to, RSA* rsa, int padding)
{
unsigned char *p, *p0;
mp_result res;
int size;
mpz_t in, out, n, e, b, bi;
int blinding = (rsa->flags & RSA_FLAG_NO_BLINDING) == 0;
int do_unblind = 0;
if (padding != RSA_PKCS1_PADDING)
return -1;
size = RSA_size(rsa);
if (size < RSA_PKCS1_PADDING_SIZE || size - RSA_PKCS1_PADDING_SIZE < flen)
return -2;
p0 = p = malloc(size);
*p++ = 0;
*p++ = 1;
memset(p, 0xff, size - flen - 3);
p += size - flen - 3;
*p++ = 0;
memcpy(p, from, flen);
p += flen;
assert((p - p0) == size);
BN2mpz(&n, rsa->n);
BN2mpz(&e, rsa->e);
mp_int_init(&in);
mp_int_init(&out);
mp_int_read_unsigned(&in, p0, size);
free(p0);
if(mp_int_compare_zero(&in) < 0 ||
mp_int_compare(&in, &n) >= 0) {
size = -3;
goto out;
}
if (blinding) {
setup_blind(&n, &b, &bi);
blind(&in, &b, &e, &n);
do_unblind = 1;
}
if (rsa->p && rsa->q && rsa->dmp1 && rsa->dmq1 && rsa->iqmp) {
mpz_t p, q, dmp1, dmq1, iqmp;
BN2mpz(&p, rsa->p);
BN2mpz(&q, rsa->q);
BN2mpz(&dmp1, rsa->dmp1);
BN2mpz(&dmq1, rsa->dmq1);
BN2mpz(&iqmp, rsa->iqmp);
res = rsa_private_calculate(&in, &p, &q, &dmp1, &dmq1, &iqmp, &out);
mp_int_clear(&p);
mp_int_clear(&q);
mp_int_clear(&dmp1);
mp_int_clear(&dmq1);
mp_int_clear(&iqmp);
if (res != MP_OK) {
size = -4;
goto out;
}
} else {
mpz_t d;
BN2mpz(&d, rsa->d);
res = mp_int_exptmod(&in, &d, &n, &out);
mp_int_clear(&d);
if (res != MP_OK) {
size = -5;
goto out;
}
}
if (do_unblind)
unblind(&out, &bi, &n);
if (size > 0) {
size_t ssize;
ssize = mp_int_unsigned_len(&out);
assert(size >= ssize);
mp_int_to_unsigned(&out, to, size);
size = ssize;
}
out:
if (do_unblind) {
mp_int_clear(&b);
mp_int_clear(&bi);
}
mp_int_clear(&e);
mp_int_clear(&n);
mp_int_clear(&in);
mp_int_clear(&out);
return size;
}
static int
imath_rsa_private_decrypt(int flen, const unsigned char* from,
unsigned char* to, RSA* rsa, int padding)
{
unsigned char *ptr;
mp_result res;
size_t size;
mpz_t in, out, n, e, b, bi;
int blinding = (rsa->flags & RSA_FLAG_NO_BLINDING) == 0;
int do_unblind = 0;
if (padding != RSA_PKCS1_PADDING)
return -1;
size = RSA_size(rsa);
if (flen > size)
return -2;
mp_int_init(&in);
mp_int_init(&out);
BN2mpz(&n, rsa->n);
BN2mpz(&e, rsa->e);
res = mp_int_read_unsigned(&in, rk_UNCONST(from), flen);
if (res != MP_OK) {
size = -1;
goto out;
}
if(mp_int_compare_zero(&in) < 0 ||
mp_int_compare(&in, &n) >= 0) {
size = -2;
goto out;
}
if (blinding) {
setup_blind(&n, &b, &bi);
blind(&in, &b, &e, &n);
do_unblind = 1;
}
if (rsa->p && rsa->q && rsa->dmp1 && rsa->dmq1 && rsa->iqmp) {
mpz_t p, q, dmp1, dmq1, iqmp;
BN2mpz(&p, rsa->p);
BN2mpz(&q, rsa->q);
BN2mpz(&dmp1, rsa->dmp1);
BN2mpz(&dmq1, rsa->dmq1);
BN2mpz(&iqmp, rsa->iqmp);
res = rsa_private_calculate(&in, &p, &q, &dmp1, &dmq1, &iqmp, &out);
mp_int_clear(&p);
mp_int_clear(&q);
mp_int_clear(&dmp1);
mp_int_clear(&dmq1);
mp_int_clear(&iqmp);
if (res != MP_OK) {
size = -3;
goto out;
}
} else {
mpz_t d;
if(mp_int_compare_zero(&in) < 0 ||
mp_int_compare(&in, &n) >= 0)
return MP_RANGE;
BN2mpz(&d, rsa->d);
res = mp_int_exptmod(&in, &d, &n, &out);
mp_int_clear(&d);
if (res != MP_OK) {
size = -4;
goto out;
}
}
if (do_unblind)
unblind(&out, &bi, &n);
ptr = to;
{
size_t ssize;
ssize = mp_int_unsigned_len(&out);
assert(size >= ssize);
mp_int_to_unsigned(&out, ptr, ssize);
size = ssize;
}
if (*ptr != 2) {
size = -5;
goto out;
}
size--; ptr++;
while (size && *ptr != 0) {
size--; ptr++;
}
if (size == 0)
return -6;
size--; ptr++;
memmove(to, ptr, size);
out:
if (do_unblind) {
mp_int_clear(&b);
mp_int_clear(&bi);
}
mp_int_clear(&e);
mp_int_clear(&n);
mp_int_clear(&in);
mp_int_clear(&out);
return size;
}
static int
random_num(mp_int num, size_t len)
{
unsigned char *p;
mp_result res;
len = (len + 7) / 8;
p = malloc(len);
if (p == NULL)
return 1;
if (RAND_bytes(p, len) != 1) {
free(p);
return 1;
}
res = mp_int_read_unsigned(num, p, len);
free(p);
if (res != MP_OK)
return 1;
return 0;
}
#define CHECK(f, v) if ((f) != (v)) { goto out; }
static int
imath_rsa_generate_key(RSA *rsa, int bits, BIGNUM *e, BN_GENCB *cb)
{
mpz_t el, p, q, n, d, dmp1, dmq1, iqmp, t1, t2, t3;
int counter, ret;
if (bits < 789)
return -1;
ret = -1;
mp_int_init(&el);
mp_int_init(&p);
mp_int_init(&q);
mp_int_init(&n);
mp_int_init(&d);
mp_int_init(&dmp1);
mp_int_init(&dmq1);
mp_int_init(&iqmp);
mp_int_init(&t1);
mp_int_init(&t2);
mp_int_init(&t3);
BN2mpz(&el, e);
counter = 0;
do {
BN_GENCB_call(cb, 2, counter++);
CHECK(random_num(&p, bits / 2 + 1), 0);
CHECK(mp_int_find_prime(&p), MP_TRUE);
CHECK(mp_int_sub_value(&p, 1, &t1), MP_OK);
CHECK(mp_int_gcd(&t1, &el, &t2), MP_OK);
} while(mp_int_compare_value(&t2, 1) != 0);
BN_GENCB_call(cb, 3, 0);
counter = 0;
do {
BN_GENCB_call(cb, 2, counter++);
CHECK(random_num(&q, bits / 2 + 1), 0);
CHECK(mp_int_find_prime(&q), MP_TRUE);
if (mp_int_compare(&p, &q) == 0)
continue;
CHECK(mp_int_sub_value(&q, 1, &t1), MP_OK);
CHECK(mp_int_gcd(&t1, &el, &t2), MP_OK);
} while(mp_int_compare_value(&t2, 1) != 0);
if (mp_int_compare(&p, &q) < 0)
mp_int_swap(&p, &q);
BN_GENCB_call(cb, 3, 1);
CHECK(mp_int_mul(&p, &q, &n), MP_OK);
CHECK(mp_int_sub_value(&p, 1, &t1), MP_OK);
CHECK(mp_int_sub_value(&q, 1, &t2), MP_OK);
CHECK(mp_int_mul(&t1, &t2, &t3), MP_OK);
CHECK(mp_int_invmod(&el, &t3, &d), MP_OK);
CHECK(mp_int_mod(&d, &t1, &dmp1), MP_OK);
CHECK(mp_int_mod(&d, &t2, &dmq1), MP_OK);
CHECK(mp_int_invmod(&q, &p, &iqmp), MP_OK);
rsa->e = mpz2BN(&el);
rsa->p = mpz2BN(&p);
rsa->q = mpz2BN(&q);
rsa->n = mpz2BN(&n);
rsa->d = mpz2BN(&d);
rsa->dmp1 = mpz2BN(&dmp1);
rsa->dmq1 = mpz2BN(&dmq1);
rsa->iqmp = mpz2BN(&iqmp);
ret = 1;
out:
mp_int_clear(&el);
mp_int_clear(&p);
mp_int_clear(&q);
mp_int_clear(&n);
mp_int_clear(&d);
mp_int_clear(&dmp1);
mp_int_clear(&dmq1);
mp_int_clear(&iqmp);
mp_int_clear(&t1);
mp_int_clear(&t2);
mp_int_clear(&t3);
return ret;
}
static int
imath_rsa_init(RSA *rsa)
{
return 1;
}
static int
imath_rsa_finish(RSA *rsa)
{
return 1;
}
const RSA_METHOD hc_rsa_imath_method = {
"hcrypto imath RSA",
imath_rsa_public_encrypt,
imath_rsa_public_decrypt,
imath_rsa_private_encrypt,
imath_rsa_private_decrypt,
NULL,
NULL,
imath_rsa_init,
imath_rsa_finish,
0,
NULL,
NULL,
NULL,
imath_rsa_generate_key
};
#endif
const RSA_METHOD *
RSA_imath_method(void)
{
#ifdef USE_HCRYPTO_IMATH
return &hc_rsa_imath_method;
#else
return NULL;
#endif
}