diff options
Diffstat (limited to 'source4/heimdal/lib/des/rsa-imath.c')
-rw-r--r-- | source4/heimdal/lib/des/rsa-imath.c | 661 |
1 files changed, 661 insertions, 0 deletions
diff --git a/source4/heimdal/lib/des/rsa-imath.c b/source4/heimdal/lib/des/rsa-imath.c new file mode 100644 index 0000000000..298affadfe --- /dev/null +++ b/source4/heimdal/lib/des/rsa-imath.c @@ -0,0 +1,661 @@ +/* + * Copyright (c) 2006 - 2007 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +RCSID("$Id: rsa-imath.c,v 1.23 2007/01/06 13:45:25 lha Exp $"); + +#include <stdio.h> +#include <stdlib.h> +#include <krb5-types.h> +#include <assert.h> + +#include <rsa.h> + +#include <roken.h> + +#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); + /* in' = (in * b^e) mod n */ + 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) +{ + /* out' = (out * 1/b) mod 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); + + /* vq = c ^ (d mod (q - 1)) mod q */ + /* vp = c ^ (d mod (p - 1)) mod p */ + 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); + + /* C2 = 1/q mod p (iqmp) */ + /* u = (vp - vq)C2 mod p. */ + 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); + + /* c ^ d mod n = vq + u q */ + 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; + assert(padlen >= 8); + + *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); + { + 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 + /* Check that the exponent is larger then 3 */ + 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); + + /* head zero was skipped by mp_int_to_unsigned */ + 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; + size_t size; + mpz_t in, out, n, e, b, bi; + int blinding = (rsa->flags & RSA_FLAG_NO_BLINDING) == 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 = 0; + goto out; + } + + if (blinding) { + setup_blind(&n, &b, &bi); + blind(&in, &b, &e, &n); + } + + 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); + } 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 = 0; + goto out; + } + } + + if (blinding) { + unblind(&out, &bi, &n); + mp_int_clear(&b); + mp_int_clear(&bi); + } + + { + size_t ssize; + ssize = mp_int_unsigned_len(&out); + assert(size >= ssize); + mp_int_to_unsigned(&out, to, size); + size = ssize; + } + +out: + 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; + + 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 = 0; + goto out; + } + + if (blinding) { + setup_blind(&n, &b, &bi); + blind(&in, &b, &e, &n); + } + + 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); + } 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 = 0; + goto out; + } + } + + if (blinding) { + unblind(&out, &bi, &n); + mp_int_clear(&b); + mp_int_clear(&bi); + } + + ptr = to; + { + size_t ssize; + ssize = mp_int_unsigned_len(&out); + assert(size >= ssize); + mp_int_to_unsigned(&out, ptr, ssize); + size = ssize; + } + + /* head zero was skipped by mp_int_to_unsigned */ + if (*ptr != 2) + return -3; + size--; ptr++; + while (size && *ptr != 0) { + size--; ptr++; + } + if (size == 0) + return -4; + size--; ptr++; + + memmove(to, ptr, size); + +out: + 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); + + /* generate p and q so that p != q and bits(pq) ~ bits */ + 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) /* don't let p and q be the same */ + 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); + + /* make p > q */ + if (mp_int_compare(&p, &q) < 0) + mp_int_swap(&p, &q); + + BN_GENCB_call(cb, 3, 1); + + /* calculate n, n = p * q */ + CHECK(mp_int_mul(&p, &q, &n), MP_OK); + + /* calculate d, d = 1/e mod (p - 1)(q - 1) */ + 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); + + /* calculate dmp1 dmp1 = d mod (p-1) */ + CHECK(mp_int_mod(&d, &t1, &dmp1), MP_OK); + /* calculate dmq1 dmq1 = d mod (q-1) */ + CHECK(mp_int_mod(&d, &t2, &dmq1), MP_OK); + /* calculate iqmp iqmp = 1/q mod p */ + CHECK(mp_int_invmod(&q, &p, &iqmp), MP_OK); + + /* fill in RSA key */ + + 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 +}; + +const RSA_METHOD * +RSA_imath_method(void) +{ + return &hc_rsa_imath_method; +} |