crypto/external/bsd/heimdal/dist/lib/hcrypto/rsa-tfm.c

   1 /*      $NetBSD: rsa-tfm.c,v 1.1.1.2 2014/04/24 12:45:30 pettai Exp $   */
   2
   3 /*
   4  * Copyright (c) 2006 - 2007, 2010 Kungliga Tekniska Högskolan
   5  * (Royal Institute of Technology, Stockholm, Sweden).
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * 3. Neither the name of the Institute nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <config.h>
  37
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <krb5/krb5-types.h>
  41 #include <assert.h>
  42
  43 #include <rsa.h>
  44
  45 #include <krb5/roken.h>
  46
  47 #ifdef USE_HCRYPTO_TFM
  48
  49 #include "tfm.h"
  50
  51 static void
  52 BN2mpz(fp_int *s, const BIGNUM *bn)
  53 {
  54     size_t len;
  55     void *p;
  56
  57     fp_init(s);
  58
  59     len = BN_num_bytes(bn);
  60     p = malloc(len);
  61     BN_bn2bin(bn, p);
  62     fp_read_unsigned_bin(s, p, len);
  63     free(p);
  64 }
  65
  66 static int
  67 tfm_rsa_private_calculate(fp_int * in, fp_int * p,  fp_int * q,
  68                           fp_int * dmp1, fp_int * dmq1, fp_int * iqmp,
  69                           fp_int * out)
  70 {
  71     fp_int vp, vq, u;
  72
  73     fp_init_multi(&vp, &vq, &u, NULL);
  74
  75     /* vq = c ^ (d mod (q - 1)) mod q */
  76     /* vp = c ^ (d mod (p - 1)) mod p */
  77     fp_mod(in, p, &u);
  78     fp_exptmod(&u, dmp1, p, &vp);
  79     fp_mod(in, q, &u);
  80     fp_exptmod(&u, dmq1, q, &vq);
  81
  82     /* C2 = 1/q mod p  (iqmp) */
  83     /* u = (vp - vq)C2 mod p. */
  84     fp_sub(&vp, &vq, &u);
  85     if (fp_isneg(&u))
  86         fp_add(&u, p, &u);
  87     fp_mul(&u, iqmp, &u);
  88     fp_mod(&u, p, &u);
  89
  90     /* c ^ d mod n = vq + u q */
  91     fp_mul(&u, q, &u);
  92     fp_add(&u, &vq, out);
  93
  94     fp_zero_multi(&vp, &vq, &u, NULL);
  95
  96     return 0;
  97 }
  98
  99 /*
 100  *
 101  */
 102
 103 static int
 104 tfm_rsa_public_encrypt(int flen, const unsigned char* from,
 105                         unsigned char* to, RSA* rsa, int padding)
 106 {
 107     unsigned char *p, *p0;
 108     int res;
 109     size_t size, padlen;
 110     fp_int enc, dec, n, e;
 111
 112     if (padding != RSA_PKCS1_PADDING)
 113         return -1;
 114
 115     size = RSA_size(rsa);
 116
 117     if (size < RSA_PKCS1_PADDING_SIZE || size - RSA_PKCS1_PADDING_SIZE < flen)
 118         return -2;
 119
 120     BN2mpz(&n, rsa->n);
 121     BN2mpz(&e, rsa->e);
 122
 123     p = p0 = malloc(size - 1);
 124     if (p0 == NULL) {
 125         fp_zero_multi(&e, &n, NULL);
 126         return -3;
 127     }
 128
 129     padlen = size - flen - 3;
 130
 131     *p++ = 2;
 132     if (RAND_bytes(p, padlen) != 1) {
 133         fp_zero_multi(&e, &n, NULL);
 134         free(p0);
 135         return -4;
 136     }
 137     while(padlen) {
 138         if (*p == 0)
 139             *p = 1;
 140         padlen--;
 141         p++;
 142     }
 143     *p++ = 0;
 144     memcpy(p, from, flen);
 145     p += flen;
 146     assert((p - p0) == size - 1);
 147
 148     fp_init_multi(&enc, &dec, NULL);
 149     fp_read_unsigned_bin(&dec, p0, size - 1);
 150     free(p0);
 151
 152     res = fp_exptmod(&dec, &e, &n, &enc);
 153
 154     fp_zero_multi(&dec, &e, &n, NULL);
 155
 156     if (res != 0)
 157         return -4;
 158
 159     {
 160         size_t ssize;
 161         ssize = fp_unsigned_bin_size(&enc);
 162         assert(size >= ssize);
 163         fp_to_unsigned_bin(&enc, to);
 164         size = ssize;
 165     }
 166     fp_zero(&enc);
 167
 168     return size;
 169 }
 170
 171 static int
 172 tfm_rsa_public_decrypt(int flen, const unsigned char* from,
 173                        unsigned char* to, RSA* rsa, int padding)
 174 {
 175     unsigned char *p;
 176     int res;
 177     size_t size;
 178     fp_int s, us, n, e;
 179
 180     if (padding != RSA_PKCS1_PADDING)
 181         return -1;
 182
 183     if (flen > RSA_size(rsa))
 184         return -2;
 185
 186     BN2mpz(&n, rsa->n);
 187     BN2mpz(&e, rsa->e);
 188
 189 #if 0
 190     /* Check that the exponent is larger then 3 */
 191     if (mp_int_compare_value(&e, 3) <= 0) {
 192         fp_zero_multi(&e, &n, NULL);
 193         return -3;
 194     }
 195 #endif
 196
 197     fp_init_multi(&s, &us, NULL);
 198     fp_read_unsigned_bin(&s, rk_UNCONST(from), flen);
 199
 200     if (fp_cmp(&s, &n) >= 0) {
 201         fp_zero_multi(&e, &n, NULL);
 202         return -4;
 203     }
 204
 205     res = fp_exptmod(&s, &e, &n, &us);
 206
 207     fp_zero_multi(&s, &e, &n, NULL);
 208
 209     if (res != 0)
 210         return -5;
 211     p = to;
 212
 213
 214     size = fp_unsigned_bin_size(&us);
 215     assert(size <= RSA_size(rsa));
 216     fp_to_unsigned_bin(&us, p);
 217
 218     fp_zero(&us);
 219
 220     /* head zero was skipped by fp_to_unsigned_bin */
 221     if (*p == 0)
 222         return -6;
 223     if (*p != 1)
 224         return -7;
 225     size--; p++;
 226     while (size && *p == 0xff) {
 227         size--; p++;
 228     }
 229     if (size == 0 || *p != 0)
 230         return -8;
 231     size--; p++;
 232
 233     memmove(to, p, size);
 234
 235     return size;
 236 }
 237
 238 static int
 239 tfm_rsa_private_encrypt(int flen, const unsigned char* from,
 240                         unsigned char* to, RSA* rsa, int padding)
 241 {
 242     unsigned char *p, *p0;
 243     int res;
 244     int size;
 245     fp_int in, out, n, e;
 246
 247     if (padding != RSA_PKCS1_PADDING)
 248         return -1;
 249
 250     size = RSA_size(rsa);
 251
 252     if (size < RSA_PKCS1_PADDING_SIZE || size - RSA_PKCS1_PADDING_SIZE < flen)
 253         return -2;
 254
 255     p0 = p = malloc(size);
 256     *p++ = 0;
 257     *p++ = 1;
 258     memset(p, 0xff, size - flen - 3);
 259     p += size - flen - 3;
 260     *p++ = 0;
 261     memcpy(p, from, flen);
 262     p += flen;
 263     assert((p - p0) == size);
 264
 265     BN2mpz(&n, rsa->n);
 266     BN2mpz(&e, rsa->e);
 267
 268     fp_init_multi(&in, &out, NULL);
 269     fp_read_unsigned_bin(&in, p0, size);
 270     free(p0);
 271
 272     if(fp_isneg(&in) || fp_cmp(&in, &n) >= 0) {
 273         size = -3;
 274         goto out;
 275     }
 276
 277     if (rsa->p && rsa->q && rsa->dmp1 && rsa->dmq1 && rsa->iqmp) {
 278         fp_int p, q, dmp1, dmq1, iqmp;
 279
 280         BN2mpz(&p, rsa->p);
 281         BN2mpz(&q, rsa->q);
 282         BN2mpz(&dmp1, rsa->dmp1);
 283         BN2mpz(&dmq1, rsa->dmq1);
 284         BN2mpz(&iqmp, rsa->iqmp);
 285
 286         res = tfm_rsa_private_calculate(&in, &p, &q, &dmp1, &dmq1, &iqmp, &out);
 287
 288         fp_zero_multi(&p, &q, &dmp1, &dmq1, &iqmp, NULL);
 289
 290         if (res != 0) {
 291             size = -4;
 292             goto out;
 293         }
 294     } else {
 295         fp_int d;
 296
 297         BN2mpz(&d, rsa->d);
 298         res = fp_exptmod(&in, &d, &n, &out);
 299         fp_zero(&d);
 300         if (res != 0) {
 301             size = -5;
 302             goto out;
 303         }
 304     }
 305
 306     if (size > 0) {
 307         size_t ssize;
 308         ssize = fp_unsigned_bin_size(&out);
 309         assert(size >= ssize);
 310         fp_to_unsigned_bin(&out, to);
 311         size = ssize;
 312     }
 313
 314  out:
 315     fp_zero_multi(&e, &n, &in, &out, NULL);
 316
 317     return size;
 318 }
 319
 320 static int
 321 tfm_rsa_private_decrypt(int flen, const unsigned char* from,
 322                         unsigned char* to, RSA* rsa, int padding)
 323 {
 324     unsigned char *ptr;
 325     int res;
 326     int size;
 327     fp_int in, out, n, e;
 328
 329     if (padding != RSA_PKCS1_PADDING)
 330         return -1;
 331
 332     size = RSA_size(rsa);
 333     if (flen > size)
 334         return -2;
 335
 336     fp_init_multi(&in, &out, NULL);
 337
 338     BN2mpz(&n, rsa->n);
 339     BN2mpz(&e, rsa->e);
 340
 341     fp_read_unsigned_bin(&in, rk_UNCONST(from), flen);
 342
 343     if(fp_isneg(&in) || fp_cmp(&in, &n) >= 0) {
 344         size = -2;
 345         goto out;
 346     }
 347
 348     if (rsa->p && rsa->q && rsa->dmp1 && rsa->dmq1 && rsa->iqmp) {
 349         fp_int p, q, dmp1, dmq1, iqmp;
 350
 351         BN2mpz(&p, rsa->p);
 352         BN2mpz(&q, rsa->q);
 353         BN2mpz(&dmp1, rsa->dmp1);
 354         BN2mpz(&dmq1, rsa->dmq1);
 355         BN2mpz(&iqmp, rsa->iqmp);
 356
 357         res = tfm_rsa_private_calculate(&in, &p, &q, &dmp1, &dmq1, &iqmp, &out);
 358
 359         fp_zero_multi(&p, &q, &dmp1, &dmq1, &iqmp, NULL);
 360
 361         if (res != 0) {
 362             size = -3;
 363             goto out;
 364         }
 365
 366     } else {
 367         fp_int d;
 368
 369         if(fp_isneg(&in) || fp_cmp(&in, &n) >= 0)
 370             return -4;
 371
 372         BN2mpz(&d, rsa->d);
 373         res = fp_exptmod(&in, &d, &n, &out);
 374         fp_zero(&d);
 375         if (res != 0) {
 376             size = -5;
 377             goto out;
 378         }
 379     }
 380
 381     ptr = to;
 382     {
 383         size_t ssize;
 384         ssize = fp_unsigned_bin_size(&out);
 385         assert(size >= ssize);
 386         fp_to_unsigned_bin(&out, ptr);
 387         size = ssize;
 388     }
 389
 390     /* head zero was skipped by mp_int_to_unsigned */
 391     if (*ptr != 2) {
 392         size = -6;
 393         goto out;
 394     }
 395     size--; ptr++;
 396     while (size && *ptr != 0) {
 397         size--; ptr++;
 398     }
 399     if (size == 0)
 400         return -7;
 401     size--; ptr++;
 402
 403     memmove(to, ptr, size);
 404
 405  out:
 406     fp_zero_multi(&e, &n, &in, &out, NULL);
 407
 408     return size;
 409 }
 410
 411 static BIGNUM *
 412 mpz2BN(fp_int *s)
 413 {
 414     size_t size;
 415     BIGNUM *bn;
 416     void *p;
 417
 418     size = fp_unsigned_bin_size(s);
 419     p = malloc(size);
 420     if (p == NULL && size != 0)
 421         return NULL;
 422
 423     fp_to_unsigned_bin(s, p);
 424
 425     bn = BN_bin2bn(p, size, NULL);
 426     free(p);
 427     return bn;
 428 }
 429
 430 static int
 431 random_num(fp_int *num, size_t len)
 432 {
 433     unsigned char *p;
 434
 435     len = (len + 7) / 8;
 436     p = malloc(len);
 437     if (p == NULL)
 438         return 1;
 439     if (RAND_bytes(p, len) != 1) {
 440         free(p);
 441         return 1;
 442     }
 443     fp_read_unsigned_bin(num, p, len);
 444     free(p);
 445     return 0;
 446 }
 447
 448 #define CHECK(f, v) if ((f) != (v)) { goto out; }
 449
 450 static int
 451 tfm_rsa_generate_key(RSA *rsa, int bits, BIGNUM *e, BN_GENCB *cb)
 452 {
 453     fp_int el, p, q, n, d, dmp1, dmq1, iqmp, t1, t2, t3;
 454     int counter, ret, bitsp;
 455
 456     if (bits < 789)
 457         return -1;
 458
 459     bitsp = (bits + 1) / 2;
 460
 461     ret = -1;
 462
 463     fp_init_multi(&el, &p, &q, &n, &n, &d, &dmp1, &dmq1, &iqmp, &t1, &t2, &t3, NULL);
 464
 465     BN2mpz(&el, e);
 466
 467     /* generate p and q so that p != q and bits(pq) ~ bits */
 468     counter = 0;
 469     do {
 470         BN_GENCB_call(cb, 2, counter++);
 471         CHECK(random_num(&p, bitsp), 0);
 472         CHECK(fp_find_prime(&p), FP_YES);
 473
 474         fp_sub_d(&p, 1, &t1);
 475         fp_gcd(&t1, &el, &t2);
 476     } while(fp_cmp_d(&t2, 1) != 0);
 477
 478     BN_GENCB_call(cb, 3, 0);
 479
 480     counter = 0;
 481     do {
 482         BN_GENCB_call(cb, 2, counter++);
 483         CHECK(random_num(&q, bits - bitsp), 0);
 484         CHECK(fp_find_prime(&q), FP_YES);
 485
 486         if (fp_cmp(&p, &q) == 0) /* don't let p and q be the same */
 487             continue;
 488
 489         fp_sub_d(&q, 1, &t1);
 490         fp_gcd(&t1, &el, &t2);
 491     } while(fp_cmp_d(&t2, 1) != 0);
 492
 493     /* make p > q */
 494     if (fp_cmp(&p, &q) < 0) {
 495         fp_int c;
 496         fp_copy(&p, &c);
 497         fp_copy(&q, &p);
 498         fp_copy(&c, &q);
 499     }
 500
 501     BN_GENCB_call(cb, 3, 1);
 502
 503     /* calculate n,             n = p * q */
 504     fp_mul(&p, &q, &n);
 505
 506     /* calculate d,             d = 1/e mod (p - 1)(q - 1) */
 507     fp_sub_d(&p, 1, &t1);
 508     fp_sub_d(&q, 1, &t2);
 509     fp_mul(&t1, &t2, &t3);
 510     fp_invmod(&el, &t3, &d);
 511
 512     /* calculate dmp1           dmp1 = d mod (p-1) */
 513     fp_mod(&d, &t1, &dmp1);
 514     /* calculate dmq1           dmq1 = d mod (q-1) */
 515     fp_mod(&d, &t2, &dmq1);
 516     /* calculate iqmp           iqmp = 1/q mod p */
 517     fp_invmod(&q, &p, &iqmp);
 518
 519     /* fill in RSA key */
 520
 521     rsa->e = mpz2BN(&el);
 522     rsa->p = mpz2BN(&p);
 523     rsa->q = mpz2BN(&q);
 524     rsa->n = mpz2BN(&n);
 525     rsa->d = mpz2BN(&d);
 526     rsa->dmp1 = mpz2BN(&dmp1);
 527     rsa->dmq1 = mpz2BN(&dmq1);
 528     rsa->iqmp = mpz2BN(&iqmp);
 529
 530     ret = 1;
 531
 532 out:
 533     fp_zero_multi(&el, &p, &q, &n, &d, &dmp1,
 534                   &dmq1, &iqmp, &t1, &t2, &t3, NULL);
 535
 536     return ret;
 537 }
 538
 539 static int
 540 tfm_rsa_init(RSA *rsa)
 541 {
 542     return 1;
 543 }
 544
 545 static int
 546 tfm_rsa_finish(RSA *rsa)
 547 {
 548     return 1;
 549 }
 550
 551 const RSA_METHOD hc_rsa_tfm_method = {
 552     "hcrypto tfm RSA",
 553     tfm_rsa_public_encrypt,
 554     tfm_rsa_public_decrypt,
 555     tfm_rsa_private_encrypt,
 556     tfm_rsa_private_decrypt,
 557     NULL,
 558     NULL,
 559     tfm_rsa_init,
 560     tfm_rsa_finish,
 561     0,
 562     NULL,
 563     NULL,
 564     NULL,
 565     tfm_rsa_generate_key
 566 };
 567
 568 #endif
 569
 570 const RSA_METHOD *
 571 RSA_tfm_method(void)
 572 {
 573 #ifdef USE_HCRYPTO_TFM
 574     return &hc_rsa_tfm_method;
 575 #else
 576     return NULL;
 577 #endif
 578 }
 579