crypto/rsa/rsa_lib.c

   1 /*
   2  * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <stdio.h>
  11 #include <openssl/crypto.h>
  12 #include "internal/cryptlib.h"
  13 #include "internal/refcount.h"
  14 #include "crypto/bn.h"
  15 #include <openssl/engine.h>
  16 #include <openssl/evp.h>
  17 #include "crypto/evp.h"
  18 #include "rsa_local.h"
  19
  20 RSA *RSA_new(void)
  21 {
  22     return RSA_new_method(NULL);
  23 }
  24
  25 const RSA_METHOD *RSA_get_method(const RSA *rsa)
  26 {
  27     return rsa->meth;
  28 }
  29
  30 int RSA_set_method(RSA *rsa, const RSA_METHOD *meth)
  31 {
  32     /*
  33      * NB: The caller is specifically setting a method, so it's not up to us
  34      * to deal with which ENGINE it comes from.
  35      */
  36     const RSA_METHOD *mtmp;
  37     mtmp = rsa->meth;
  38     if (mtmp->finish)
  39         mtmp->finish(rsa);
  40 #ifndef OPENSSL_NO_ENGINE
  41     ENGINE_finish(rsa->engine);
  42     rsa->engine = NULL;
  43 #endif
  44     rsa->meth = meth;
  45     if (meth->init)
  46         meth->init(rsa);
  47     return 1;
  48 }
  49
  50 RSA *RSA_new_method(ENGINE *engine)
  51 {
  52     RSA *ret = OPENSSL_zalloc(sizeof(*ret));
  53
  54     if (ret == NULL) {
  55         RSAerr(RSA_F_RSA_NEW_METHOD, ERR_R_MALLOC_FAILURE);
  56         return NULL;
  57     }
  58
  59     ret->references = 1;
  60     ret->lock = CRYPTO_THREAD_lock_new();
  61     if (ret->lock == NULL) {
  62         RSAerr(RSA_F_RSA_NEW_METHOD, ERR_R_MALLOC_FAILURE);
  63         OPENSSL_free(ret);
  64         return NULL;
  65     }
  66
  67     ret->meth = RSA_get_default_method();
  68 #ifndef OPENSSL_NO_ENGINE
  69     ret->flags = ret->meth->flags & ~RSA_FLAG_NON_FIPS_ALLOW;
  70     if (engine) {
  71         if (!ENGINE_init(engine)) {
  72             RSAerr(RSA_F_RSA_NEW_METHOD, ERR_R_ENGINE_LIB);
  73             goto err;
  74         }
  75         ret->engine = engine;
  76     } else {
  77         ret->engine = ENGINE_get_default_RSA();
  78     }
  79     if (ret->engine) {
  80         ret->meth = ENGINE_get_RSA(ret->engine);
  81         if (ret->meth == NULL) {
  82             RSAerr(RSA_F_RSA_NEW_METHOD, ERR_R_ENGINE_LIB);
  83             goto err;
  84         }
  85     }
  86 #endif
  87
  88     ret->flags = ret->meth->flags & ~RSA_FLAG_NON_FIPS_ALLOW;
  89     if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_RSA, ret, &ret->ex_data)) {
  90         goto err;
  91     }
  92
  93     if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
  94         RSAerr(RSA_F_RSA_NEW_METHOD, ERR_R_INIT_FAIL);
  95         goto err;
  96     }
  97
  98     return ret;
  99
 100  err:
 101     RSA_free(ret);
 102     return NULL;
 103 }
 104
 105 void RSA_free(RSA *r)
 106 {
 107     int i;
 108
 109     if (r == NULL)
 110         return;
 111
 112     CRYPTO_DOWN_REF(&r->references, &i, r->lock);
 113     REF_PRINT_COUNT("RSA", r);
 114     if (i > 0)
 115         return;
 116     REF_ASSERT_ISNT(i < 0);
 117
 118     if (r->meth != NULL && r->meth->finish != NULL)
 119         r->meth->finish(r);
 120 #ifndef OPENSSL_NO_ENGINE
 121     ENGINE_finish(r->engine);
 122 #endif
 123
 124     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_RSA, r, &r->ex_data);
 125
 126     CRYPTO_THREAD_lock_free(r->lock);
 127
 128     BN_free(r->n);
 129     BN_free(r->e);
 130     BN_clear_free(r->d);
 131     BN_clear_free(r->p);
 132     BN_clear_free(r->q);
 133     BN_clear_free(r->dmp1);
 134     BN_clear_free(r->dmq1);
 135     BN_clear_free(r->iqmp);
 136     RSA_PSS_PARAMS_free(r->pss);
 137     sk_RSA_PRIME_INFO_pop_free(r->prime_infos, rsa_multip_info_free);
 138     BN_BLINDING_free(r->blinding);
 139     BN_BLINDING_free(r->mt_blinding);
 140     OPENSSL_free(r->bignum_data);
 141     OPENSSL_free(r);
 142 }
 143
 144 int RSA_up_ref(RSA *r)
 145 {
 146     int i;
 147
 148     if (CRYPTO_UP_REF(&r->references, &i, r->lock) <= 0)
 149         return 0;
 150
 151     REF_PRINT_COUNT("RSA", r);
 152     REF_ASSERT_ISNT(i < 2);
 153     return i > 1 ? 1 : 0;
 154 }
 155
 156 int RSA_set_ex_data(RSA *r, int idx, void *arg)
 157 {
 158     return CRYPTO_set_ex_data(&r->ex_data, idx, arg);
 159 }
 160
 161 void *RSA_get_ex_data(const RSA *r, int idx)
 162 {
 163     return CRYPTO_get_ex_data(&r->ex_data, idx);
 164 }
 165
 166 /*
 167  * Define a scaling constant for our fixed point arithmetic.
 168  * This value must be a power of two because the base two logarithm code
 169  * makes this assumption.  The exponent must also be a multiple of three so
 170  * that the scale factor has an exact cube root.  Finally, the scale factor
 171  * should not be so large that a multiplication of two scaled numbers
 172  * overflows a 64 bit unsigned integer.
 173  */
 174 static const unsigned int scale = 1 << 18;
 175 static const unsigned int cbrt_scale = 1 << (2 * 18 / 3);
 176
 177 /* Define some constants, none exceed 32 bits */
 178 static const unsigned int log_2  = 0x02c5c8;    /* scale * log(2) */
 179 static const unsigned int log_e  = 0x05c551;    /* scale * log2(M_E) */
 180 static const unsigned int c1_923 = 0x07b126;    /* scale * 1.923 */
 181 static const unsigned int c4_690 = 0x12c28f;    /* scale * 4.690 */
 182
 183 /*
 184  * Multiply two scaled integers together and rescale the result.
 185  */
 186 static ossl_inline uint64_t mul2(uint64_t a, uint64_t b)
 187 {
 188     return a * b / scale;
 189 }
 190
 191 /*
 192  * Calculate the cube root of a 64 bit scaled integer.
 193  * Although the cube root of a 64 bit number does fit into a 32 bit unsigned
 194  * integer, this is not guaranteed after scaling, so this function has a
 195  * 64 bit return.  This uses the shifting nth root algorithm with some
 196  * algebraic simplifications.
 197  */
 198 static uint64_t icbrt64(uint64_t x)
 199 {
 200     uint64_t r = 0;
 201     uint64_t b;
 202     int s;
 203
 204     for (s = 63; s >= 0; s -= 3) {
 205         r <<= 1;
 206         b = 3 * r * (r + 1) + 1;
 207         if ((x >> s) >= b) {
 208             x -= b << s;
 209             r++;
 210         }
 211     }
 212     return r * cbrt_scale;
 213 }
 214
 215 /*
 216  * Calculate the natural logarithm of a 64 bit scaled integer.
 217  * This is done by calculating a base two logarithm and scaling.
 218  * The maximum logarithm (base 2) is 64 and this reduces base e, so
 219  * a 32 bit result should not overflow.  The argument passed must be
 220  * greater than unity so we don't need to handle negative results.
 221  */
 222 static uint32_t ilog_e(uint64_t v)
 223 {
 224     uint32_t i, r = 0;
 225
 226     /*
 227      * Scale down the value into the range 1 .. 2.
 228      *
 229      * If fractional numbers need to be processed, another loop needs
 230      * to go here that checks v < scale and if so multiplies it by 2 and
 231      * reduces r by scale.  This also means making r signed.
 232      */
 233     while (v >= 2 * scale) {
 234         v >>= 1;
 235         r += scale;
 236     }
 237     for (i = scale / 2; i != 0; i /= 2) {
 238         v = mul2(v, v);
 239         if (v >= 2 * scale) {
 240             v >>= 1;
 241             r += i;
 242         }
 243     }
 244     r = (r * (uint64_t)scale) / log_e;
 245     return r;
 246 }
 247
 248 /*
 249  * NIST SP 800-56B rev 2 Appendix D: Maximum Security Strength Estimates for IFC
 250  * Modulus Lengths.
 251  *
 252  * E = \frac{1.923 \sqrt[3]{nBits \cdot log_e(2)}
 253  *           \cdot(log_e(nBits \cdot log_e(2))^{2/3} - 4.69}{log_e(2)}
 254  * The two cube roots are merged together here.
 255  */
 256 uint16_t rsa_compute_security_bits(int n)
 257 {
 258     uint64_t x;
 259     uint32_t lx;
 260     uint16_t y;
 261
 262     /* Look for common values as listed in SP 800-56B rev 2 Appendix D */
 263     switch (n) {
 264     case 2048:
 265         return 112;
 266     case 3072:
 267         return 128;
 268     case 4096:
 269         return 152;
 270     case 6144:
 271         return 176;
 272     case 8192:
 273         return 200;
 274     }
 275     /*
 276      * The first incorrect result (i.e. not accurate or off by one low) occurs
 277      * for n = 699668.  The true value here is 1200.  Instead of using this n
 278      * as the check threshold, the smallest n such that the correct result is
 279      * 1200 is used instead.
 280      */
 281     if (n >= 687737)
 282         return 1200;
 283     if (n < 8)
 284         return 0;
 285
 286     x = n * (uint64_t)log_2;
 287     lx = ilog_e(x);
 288     y = (uint16_t)((mul2(c1_923, icbrt64(mul2(mul2(x, lx), lx))) - c4_690)
 289                    / log_2);
 290     return (y + 4) & ~7;
 291 }
 292
 293 int RSA_security_bits(const RSA *rsa)
 294 {
 295     int bits = BN_num_bits(rsa->n);
 296
 297     if (rsa->version == RSA_ASN1_VERSION_MULTI) {
 298         /* This ought to mean that we have private key at hand. */
 299         int ex_primes = sk_RSA_PRIME_INFO_num(rsa->prime_infos);
 300
 301         if (ex_primes <= 0 || (ex_primes + 2) > rsa_multip_cap(bits))
 302             return 0;
 303     }
 304     return rsa_compute_security_bits(bits);
 305 }
 306
 307 int RSA_set0_key(RSA *r, BIGNUM *n, BIGNUM *e, BIGNUM *d)
 308 {
 309     /* If the fields n and e in r are NULL, the corresponding input
 310      * parameters MUST be non-NULL for n and e.  d may be
 311      * left NULL (in case only the public key is used).
 312      */
 313     if ((r->n == NULL && n == NULL)
 314         || (r->e == NULL && e == NULL))
 315         return 0;
 316
 317     if (n != NULL) {
 318         BN_free(r->n);
 319         r->n = n;
 320     }
 321     if (e != NULL) {
 322         BN_free(r->e);
 323         r->e = e;
 324     }
 325     if (d != NULL) {
 326         BN_clear_free(r->d);
 327         r->d = d;
 328         BN_set_flags(r->d, BN_FLG_CONSTTIME);
 329     }
 330
 331     return 1;
 332 }
 333
 334 int RSA_set0_factors(RSA *r, BIGNUM *p, BIGNUM *q)
 335 {
 336     /* If the fields p and q in r are NULL, the corresponding input
 337      * parameters MUST be non-NULL.
 338      */
 339     if ((r->p == NULL && p == NULL)
 340         || (r->q == NULL && q == NULL))
 341         return 0;
 342
 343     if (p != NULL) {
 344         BN_clear_free(r->p);
 345         r->p = p;
 346         BN_set_flags(r->p, BN_FLG_CONSTTIME);
 347     }
 348     if (q != NULL) {
 349         BN_clear_free(r->q);
 350         r->q = q;
 351         BN_set_flags(r->q, BN_FLG_CONSTTIME);
 352     }
 353
 354     return 1;
 355 }
 356
 357 int RSA_set0_crt_params(RSA *r, BIGNUM *dmp1, BIGNUM *dmq1, BIGNUM *iqmp)
 358 {
 359     /* If the fields dmp1, dmq1 and iqmp in r are NULL, the corresponding input
 360      * parameters MUST be non-NULL.
 361      */
 362     if ((r->dmp1 == NULL && dmp1 == NULL)
 363         || (r->dmq1 == NULL && dmq1 == NULL)
 364         || (r->iqmp == NULL && iqmp == NULL))
 365         return 0;
 366
 367     if (dmp1 != NULL) {
 368         BN_clear_free(r->dmp1);
 369         r->dmp1 = dmp1;
 370         BN_set_flags(r->dmp1, BN_FLG_CONSTTIME);
 371     }
 372     if (dmq1 != NULL) {
 373         BN_clear_free(r->dmq1);
 374         r->dmq1 = dmq1;
 375         BN_set_flags(r->dmq1, BN_FLG_CONSTTIME);
 376     }
 377     if (iqmp != NULL) {
 378         BN_clear_free(r->iqmp);
 379         r->iqmp = iqmp;
 380         BN_set_flags(r->iqmp, BN_FLG_CONSTTIME);
 381     }
 382
 383     return 1;
 384 }
 385
 386 /*
 387  * Is it better to export RSA_PRIME_INFO structure
 388  * and related functions to let user pass a triplet?
 389  */
 390 int RSA_set0_multi_prime_params(RSA *r, BIGNUM *primes[], BIGNUM *exps[],
 391                                 BIGNUM *coeffs[], int pnum)
 392 {
 393     STACK_OF(RSA_PRIME_INFO) *prime_infos, *old = NULL;
 394     RSA_PRIME_INFO *pinfo;
 395     int i;
 396
 397     if (primes == NULL || exps == NULL || coeffs == NULL || pnum == 0)
 398         return 0;
 399
 400     prime_infos = sk_RSA_PRIME_INFO_new_reserve(NULL, pnum);
 401     if (prime_infos == NULL)
 402         return 0;
 403
 404     if (r->prime_infos != NULL)
 405         old = r->prime_infos;
 406
 407     for (i = 0; i < pnum; i++) {
 408         pinfo = rsa_multip_info_new();
 409         if (pinfo == NULL)
 410             goto err;
 411         if (primes[i] != NULL && exps[i] != NULL && coeffs[i] != NULL) {
 412             BN_clear_free(pinfo->r);
 413             BN_clear_free(pinfo->d);
 414             BN_clear_free(pinfo->t);
 415             pinfo->r = primes[i];
 416             pinfo->d = exps[i];
 417             pinfo->t = coeffs[i];
 418             BN_set_flags(pinfo->r, BN_FLG_CONSTTIME);
 419             BN_set_flags(pinfo->d, BN_FLG_CONSTTIME);
 420             BN_set_flags(pinfo->t, BN_FLG_CONSTTIME);
 421         } else {
 422             rsa_multip_info_free(pinfo);
 423             goto err;
 424         }
 425         (void)sk_RSA_PRIME_INFO_push(prime_infos, pinfo);
 426     }
 427
 428     r->prime_infos = prime_infos;
 429
 430     if (!rsa_multip_calc_product(r)) {
 431         r->prime_infos = old;
 432         goto err;
 433     }
 434
 435     if (old != NULL) {
 436         /*
 437          * This is hard to deal with, since the old infos could
 438          * also be set by this function and r, d, t should not
 439          * be freed in that case. So currently, stay consistent
 440          * with other *set0* functions: just free it...
 441          */
 442         sk_RSA_PRIME_INFO_pop_free(old, rsa_multip_info_free);
 443     }
 444
 445     r->version = RSA_ASN1_VERSION_MULTI;
 446
 447     return 1;
 448  err:
 449     /* r, d, t should not be freed */
 450     sk_RSA_PRIME_INFO_pop_free(prime_infos, rsa_multip_info_free_ex);
 451     return 0;
 452 }
 453
 454 void RSA_get0_key(const RSA *r,
 455                   const BIGNUM **n, const BIGNUM **e, const BIGNUM **d)
 456 {
 457     if (n != NULL)
 458         *n = r->n;
 459     if (e != NULL)
 460         *e = r->e;
 461     if (d != NULL)
 462         *d = r->d;
 463 }
 464
 465 void RSA_get0_factors(const RSA *r, const BIGNUM **p, const BIGNUM **q)
 466 {
 467     if (p != NULL)
 468         *p = r->p;
 469     if (q != NULL)
 470         *q = r->q;
 471 }
 472
 473 int RSA_get_multi_prime_extra_count(const RSA *r)
 474 {
 475     int pnum;
 476
 477     pnum = sk_RSA_PRIME_INFO_num(r->prime_infos);
 478     if (pnum <= 0)
 479         pnum = 0;
 480     return pnum;
 481 }
 482
 483 int RSA_get0_multi_prime_factors(const RSA *r, const BIGNUM *primes[])
 484 {
 485     int pnum, i;
 486     RSA_PRIME_INFO *pinfo;
 487
 488     if ((pnum = RSA_get_multi_prime_extra_count(r)) == 0)
 489         return 0;
 490
 491     /*
 492      * return other primes
 493      * it's caller's responsibility to allocate oth_primes[pnum]
 494      */
 495     for (i = 0; i < pnum; i++) {
 496         pinfo = sk_RSA_PRIME_INFO_value(r->prime_infos, i);
 497         primes[i] = pinfo->r;
 498     }
 499
 500     return 1;
 501 }
 502
 503 void RSA_get0_crt_params(const RSA *r,
 504                          const BIGNUM **dmp1, const BIGNUM **dmq1,
 505                          const BIGNUM **iqmp)
 506 {
 507     if (dmp1 != NULL)
 508         *dmp1 = r->dmp1;
 509     if (dmq1 != NULL)
 510         *dmq1 = r->dmq1;
 511     if (iqmp != NULL)
 512         *iqmp = r->iqmp;
 513 }
 514
 515 int RSA_get0_multi_prime_crt_params(const RSA *r, const BIGNUM *exps[],
 516                                     const BIGNUM *coeffs[])
 517 {
 518     int pnum;
 519
 520     if ((pnum = RSA_get_multi_prime_extra_count(r)) == 0)
 521         return 0;
 522
 523     /* return other primes */
 524     if (exps != NULL || coeffs != NULL) {
 525         RSA_PRIME_INFO *pinfo;
 526         int i;
 527
 528         /* it's the user's job to guarantee the buffer length */
 529         for (i = 0; i < pnum; i++) {
 530             pinfo = sk_RSA_PRIME_INFO_value(r->prime_infos, i);
 531             if (exps != NULL)
 532                 exps[i] = pinfo->d;
 533             if (coeffs != NULL)
 534                 coeffs[i] = pinfo->t;
 535         }
 536     }
 537
 538     return 1;
 539 }
 540
 541 const BIGNUM *RSA_get0_n(const RSA *r)
 542 {
 543     return r->n;
 544 }
 545
 546 const BIGNUM *RSA_get0_e(const RSA *r)
 547 {
 548     return r->e;
 549 }
 550
 551 const BIGNUM *RSA_get0_d(const RSA *r)
 552 {
 553     return r->d;
 554 }
 555
 556 const BIGNUM *RSA_get0_p(const RSA *r)
 557 {
 558     return r->p;
 559 }
 560
 561 const BIGNUM *RSA_get0_q(const RSA *r)
 562 {
 563     return r->q;
 564 }
 565
 566 const BIGNUM *RSA_get0_dmp1(const RSA *r)
 567 {
 568     return r->dmp1;
 569 }
 570
 571 const BIGNUM *RSA_get0_dmq1(const RSA *r)
 572 {
 573     return r->dmq1;
 574 }
 575
 576 const BIGNUM *RSA_get0_iqmp(const RSA *r)
 577 {
 578     return r->iqmp;
 579 }
 580
 581 void RSA_clear_flags(RSA *r, int flags)
 582 {
 583     r->flags &= ~flags;
 584 }
 585
 586 int RSA_test_flags(const RSA *r, int flags)
 587 {
 588     return r->flags & flags;
 589 }
 590
 591 void RSA_set_flags(RSA *r, int flags)
 592 {
 593     r->flags |= flags;
 594 }
 595
 596 int RSA_get_version(RSA *r)
 597 {
 598     /* { two-prime(0), multi(1) } */
 599     return r->version;
 600 }
 601
 602 ENGINE *RSA_get0_engine(const RSA *r)
 603 {
 604     return r->engine;
 605 }
 606
 607 int RSA_pkey_ctx_ctrl(EVP_PKEY_CTX *ctx, int optype, int cmd, int p1, void *p2)
 608 {
 609     /* If key type not RSA or RSA-PSS return error */
 610     if (ctx != NULL && ctx->pmeth != NULL
 611         && ctx->pmeth->pkey_id != EVP_PKEY_RSA
 612         && ctx->pmeth->pkey_id != EVP_PKEY_RSA_PSS)
 613         return -1;
 614      return EVP_PKEY_CTX_ctrl(ctx, -1, optype, cmd, p1, p2);
 615 }