crypto/rsa/rsa_ameth.c

   1 /*
   2  * Copyright 2006-2021 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 /*
  11  * RSA low level APIs are deprecated for public use, but still ok for
  12  * internal use.
  13  */
  14 #include "internal/deprecated.h"
  15
  16 #include <stdio.h>
  17 #include "internal/cryptlib.h"
  18 #include <openssl/asn1t.h>
  19 #include <openssl/x509.h>
  20 #include <openssl/bn.h>
  21 #include <openssl/core_names.h>
  22 #include <openssl/param_build.h>
  23 #include "crypto/asn1.h"
  24 #include "crypto/evp.h"
  25 #include "crypto/rsa.h"
  26 #include "rsa_local.h"
  27
  28 static RSA_PSS_PARAMS *rsa_pss_decode(const X509_ALGOR *alg);
  29 static int rsa_sync_to_pss_params_30(RSA *rsa);
  30
  31 /* Set any parameters associated with pkey */
  32 static int rsa_param_encode(const EVP_PKEY *pkey,
  33                             ASN1_STRING **pstr, int *pstrtype)
  34 {
  35     const RSA *rsa = pkey->pkey.rsa;
  36
  37     *pstr = NULL;
  38     /* If RSA it's just NULL type */
  39     if (RSA_test_flags(rsa, RSA_FLAG_TYPE_MASK) != RSA_FLAG_TYPE_RSASSAPSS) {
  40         *pstrtype = V_ASN1_NULL;
  41         return 1;
  42     }
  43     /* If no PSS parameters we omit parameters entirely */
  44     if (rsa->pss == NULL) {
  45         *pstrtype = V_ASN1_UNDEF;
  46         return 1;
  47     }
  48     /* Encode PSS parameters */
  49     if (ASN1_item_pack(rsa->pss, ASN1_ITEM_rptr(RSA_PSS_PARAMS), pstr) == NULL)
  50         return 0;
  51
  52     *pstrtype = V_ASN1_SEQUENCE;
  53     return 1;
  54 }
  55 /* Decode any parameters and set them in RSA structure */
  56 static int rsa_param_decode(RSA *rsa, const X509_ALGOR *alg)
  57 {
  58     const ASN1_OBJECT *algoid;
  59     const void *algp;
  60     int algptype;
  61
  62     X509_ALGOR_get0(&algoid, &algptype, &algp, alg);
  63     if (OBJ_obj2nid(algoid) != EVP_PKEY_RSA_PSS)
  64         return 1;
  65     if (algptype == V_ASN1_UNDEF)
  66         return 1;
  67     if (algptype != V_ASN1_SEQUENCE) {
  68         ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_PSS_PARAMETERS);
  69         return 0;
  70     }
  71     rsa->pss = rsa_pss_decode(alg);
  72     if (rsa->pss == NULL)
  73         return 0;
  74     if (!rsa_sync_to_pss_params_30(rsa))
  75         return 0;
  76     return 1;
  77 }
  78
  79 static int rsa_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
  80 {
  81     unsigned char *penc = NULL;
  82     int penclen;
  83     ASN1_STRING *str;
  84     int strtype;
  85
  86     if (!rsa_param_encode(pkey, &str, &strtype))
  87         return 0;
  88     penclen = i2d_RSAPublicKey(pkey->pkey.rsa, &penc);
  89     if (penclen <= 0)
  90         return 0;
  91     if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
  92                                strtype, str, penc, penclen))
  93         return 1;
  94
  95     OPENSSL_free(penc);
  96     return 0;
  97 }
  98
  99 static int rsa_pub_decode(EVP_PKEY *pkey, const X509_PUBKEY *pubkey)
 100 {
 101     const unsigned char *p;
 102     int pklen;
 103     X509_ALGOR *alg;
 104     RSA *rsa = NULL;
 105
 106     if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &alg, pubkey))
 107         return 0;
 108     if ((rsa = d2i_RSAPublicKey(NULL, &p, pklen)) == NULL)
 109         return 0;
 110     if (!rsa_param_decode(rsa, alg)) {
 111         RSA_free(rsa);
 112         return 0;
 113     }
 114
 115     RSA_clear_flags(rsa, RSA_FLAG_TYPE_MASK);
 116     switch (pkey->ameth->pkey_id) {
 117     case EVP_PKEY_RSA:
 118         RSA_set_flags(rsa, RSA_FLAG_TYPE_RSA);
 119         break;
 120     case EVP_PKEY_RSA_PSS:
 121         RSA_set_flags(rsa, RSA_FLAG_TYPE_RSASSAPSS);
 122         break;
 123     default:
 124         /* Leave the type bits zero */
 125         break;
 126     }
 127
 128     if (!EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, rsa)) {
 129         RSA_free(rsa);
 130         return 0;
 131     }
 132     return 1;
 133 }
 134
 135 static int rsa_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 136 {
 137     /*
 138      * Don't check the public/private key, this is mostly for smart
 139      * cards.
 140      */
 141     if (((RSA_flags(a->pkey.rsa) & RSA_METHOD_FLAG_NO_CHECK))
 142             || (RSA_flags(b->pkey.rsa) & RSA_METHOD_FLAG_NO_CHECK)) {
 143         return 1;
 144     }
 145
 146     if (BN_cmp(b->pkey.rsa->n, a->pkey.rsa->n) != 0
 147         || BN_cmp(b->pkey.rsa->e, a->pkey.rsa->e) != 0)
 148         return 0;
 149     return 1;
 150 }
 151
 152 static int old_rsa_priv_decode(EVP_PKEY *pkey,
 153                                const unsigned char **pder, int derlen)
 154 {
 155     RSA *rsa;
 156
 157     if ((rsa = d2i_RSAPrivateKey(NULL, pder, derlen)) == NULL)
 158         return 0;
 159     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, rsa);
 160     return 1;
 161 }
 162
 163 static int old_rsa_priv_encode(const EVP_PKEY *pkey, unsigned char **pder)
 164 {
 165     return i2d_RSAPrivateKey(pkey->pkey.rsa, pder);
 166 }
 167
 168 static int rsa_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 169 {
 170     unsigned char *rk = NULL;
 171     int rklen;
 172     ASN1_STRING *str;
 173     int strtype;
 174
 175     if (!rsa_param_encode(pkey, &str, &strtype))
 176         return 0;
 177     rklen = i2d_RSAPrivateKey(pkey->pkey.rsa, &rk);
 178
 179     if (rklen <= 0) {
 180         ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE);
 181         ASN1_STRING_free(str);
 182         return 0;
 183     }
 184
 185     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
 186                          strtype, str, rk, rklen)) {
 187         ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE);
 188         ASN1_STRING_free(str);
 189         return 0;
 190     }
 191
 192     return 1;
 193 }
 194
 195 static int rsa_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
 196 {
 197     const unsigned char *p;
 198     RSA *rsa;
 199     int pklen;
 200     const X509_ALGOR *alg;
 201
 202     if (!PKCS8_pkey_get0(NULL, &p, &pklen, &alg, p8))
 203         return 0;
 204     rsa = d2i_RSAPrivateKey(NULL, &p, pklen);
 205     if (rsa == NULL) {
 206         ERR_raise(ERR_LIB_RSA, ERR_R_RSA_LIB);
 207         return 0;
 208     }
 209     if (!rsa_param_decode(rsa, alg)) {
 210         RSA_free(rsa);
 211         return 0;
 212     }
 213
 214     RSA_clear_flags(rsa, RSA_FLAG_TYPE_MASK);
 215     switch (pkey->ameth->pkey_id) {
 216     case EVP_PKEY_RSA:
 217         RSA_set_flags(rsa, RSA_FLAG_TYPE_RSA);
 218         break;
 219     case EVP_PKEY_RSA_PSS:
 220         RSA_set_flags(rsa, RSA_FLAG_TYPE_RSASSAPSS);
 221         break;
 222     default:
 223         /* Leave the type bits zero */
 224         break;
 225     }
 226
 227     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, rsa);
 228     return 1;
 229 }
 230
 231 static int int_rsa_size(const EVP_PKEY *pkey)
 232 {
 233     return RSA_size(pkey->pkey.rsa);
 234 }
 235
 236 static int rsa_bits(const EVP_PKEY *pkey)
 237 {
 238     return BN_num_bits(pkey->pkey.rsa->n);
 239 }
 240
 241 static int rsa_security_bits(const EVP_PKEY *pkey)
 242 {
 243     return RSA_security_bits(pkey->pkey.rsa);
 244 }
 245
 246 static void int_rsa_free(EVP_PKEY *pkey)
 247 {
 248     RSA_free(pkey->pkey.rsa);
 249 }
 250
 251 static int rsa_pss_param_print(BIO *bp, int pss_key, RSA_PSS_PARAMS *pss,
 252                                int indent)
 253 {
 254     int rv = 0;
 255     X509_ALGOR *maskHash = NULL;
 256
 257     if (!BIO_indent(bp, indent, 128))
 258         goto err;
 259     if (pss_key) {
 260         if (pss == NULL) {
 261             if (BIO_puts(bp, "No PSS parameter restrictions\n") <= 0)
 262                 return 0;
 263             return 1;
 264         } else {
 265             if (BIO_puts(bp, "PSS parameter restrictions:") <= 0)
 266                 return 0;
 267         }
 268     } else if (pss == NULL) {
 269         if (BIO_puts(bp,"(INVALID PSS PARAMETERS)\n") <= 0)
 270             return 0;
 271         return 1;
 272     }
 273     if (BIO_puts(bp, "\n") <= 0)
 274         goto err;
 275     if (pss_key)
 276         indent += 2;
 277     if (!BIO_indent(bp, indent, 128))
 278         goto err;
 279     if (BIO_puts(bp, "Hash Algorithm: ") <= 0)
 280         goto err;
 281
 282     if (pss->hashAlgorithm) {
 283         if (i2a_ASN1_OBJECT(bp, pss->hashAlgorithm->algorithm) <= 0)
 284             goto err;
 285     } else if (BIO_puts(bp, "sha1 (default)") <= 0) {
 286         goto err;
 287     }
 288
 289     if (BIO_puts(bp, "\n") <= 0)
 290         goto err;
 291
 292     if (!BIO_indent(bp, indent, 128))
 293         goto err;
 294
 295     if (BIO_puts(bp, "Mask Algorithm: ") <= 0)
 296         goto err;
 297     if (pss->maskGenAlgorithm) {
 298         if (i2a_ASN1_OBJECT(bp, pss->maskGenAlgorithm->algorithm) <= 0)
 299             goto err;
 300         if (BIO_puts(bp, " with ") <= 0)
 301             goto err;
 302         maskHash = x509_algor_mgf1_decode(pss->maskGenAlgorithm);
 303         if (maskHash != NULL) {
 304             if (i2a_ASN1_OBJECT(bp, maskHash->algorithm) <= 0)
 305                 goto err;
 306         } else if (BIO_puts(bp, "INVALID") <= 0) {
 307             goto err;
 308         }
 309     } else if (BIO_puts(bp, "mgf1 with sha1 (default)") <= 0) {
 310         goto err;
 311     }
 312     BIO_puts(bp, "\n");
 313
 314     if (!BIO_indent(bp, indent, 128))
 315         goto err;
 316     if (BIO_printf(bp, "%s Salt Length: 0x", pss_key ? "Minimum" : "") <= 0)
 317         goto err;
 318     if (pss->saltLength) {
 319         if (i2a_ASN1_INTEGER(bp, pss->saltLength) <= 0)
 320             goto err;
 321     } else if (BIO_puts(bp, "14 (default)") <= 0) {
 322         goto err;
 323     }
 324     BIO_puts(bp, "\n");
 325
 326     if (!BIO_indent(bp, indent, 128))
 327         goto err;
 328     if (BIO_puts(bp, "Trailer Field: 0x") <= 0)
 329         goto err;
 330     if (pss->trailerField) {
 331         if (i2a_ASN1_INTEGER(bp, pss->trailerField) <= 0)
 332             goto err;
 333     } else if (BIO_puts(bp, "BC (default)") <= 0) {
 334         goto err;
 335     }
 336     BIO_puts(bp, "\n");
 337
 338     rv = 1;
 339
 340  err:
 341     X509_ALGOR_free(maskHash);
 342     return rv;
 343
 344 }
 345
 346 static int pkey_rsa_print(BIO *bp, const EVP_PKEY *pkey, int off, int priv)
 347 {
 348     const RSA *x = pkey->pkey.rsa;
 349     char *str;
 350     const char *s;
 351     int ret = 0, mod_len = 0, ex_primes;
 352
 353     if (x->n != NULL)
 354         mod_len = BN_num_bits(x->n);
 355     ex_primes = sk_RSA_PRIME_INFO_num(x->prime_infos);
 356
 357     if (!BIO_indent(bp, off, 128))
 358         goto err;
 359
 360     if (BIO_printf(bp, "%s ", pkey_is_pss(pkey) ?  "RSA-PSS" : "RSA") <= 0)
 361         goto err;
 362
 363     if (priv && x->d) {
 364         if (BIO_printf(bp, "Private-Key: (%d bit, %d primes)\n",
 365                        mod_len, ex_primes <= 0 ? 2 : ex_primes + 2) <= 0)
 366             goto err;
 367         str = "modulus:";
 368         s = "publicExponent:";
 369     } else {
 370         if (BIO_printf(bp, "Public-Key: (%d bit)\n", mod_len) <= 0)
 371             goto err;
 372         str = "Modulus:";
 373         s = "Exponent:";
 374     }
 375     if (!ASN1_bn_print(bp, str, x->n, NULL, off))
 376         goto err;
 377     if (!ASN1_bn_print(bp, s, x->e, NULL, off))
 378         goto err;
 379     if (priv) {
 380         int i;
 381
 382         if (!ASN1_bn_print(bp, "privateExponent:", x->d, NULL, off))
 383             goto err;
 384         if (!ASN1_bn_print(bp, "prime1:", x->p, NULL, off))
 385             goto err;
 386         if (!ASN1_bn_print(bp, "prime2:", x->q, NULL, off))
 387             goto err;
 388         if (!ASN1_bn_print(bp, "exponent1:", x->dmp1, NULL, off))
 389             goto err;
 390         if (!ASN1_bn_print(bp, "exponent2:", x->dmq1, NULL, off))
 391             goto err;
 392         if (!ASN1_bn_print(bp, "coefficient:", x->iqmp, NULL, off))
 393             goto err;
 394         for (i = 0; i < sk_RSA_PRIME_INFO_num(x->prime_infos); i++) {
 395             /* print multi-prime info */
 396             BIGNUM *bn = NULL;
 397             RSA_PRIME_INFO *pinfo;
 398             int j;
 399
 400             pinfo = sk_RSA_PRIME_INFO_value(x->prime_infos, i);
 401             for (j = 0; j < 3; j++) {
 402                 if (!BIO_indent(bp, off, 128))
 403                     goto err;
 404                 switch (j) {
 405                 case 0:
 406                     if (BIO_printf(bp, "prime%d:", i + 3) <= 0)
 407                         goto err;
 408                     bn = pinfo->r;
 409                     break;
 410                 case 1:
 411                     if (BIO_printf(bp, "exponent%d:", i + 3) <= 0)
 412                         goto err;
 413                     bn = pinfo->d;
 414                     break;
 415                 case 2:
 416                     if (BIO_printf(bp, "coefficient%d:", i + 3) <= 0)
 417                         goto err;
 418                     bn = pinfo->t;
 419                     break;
 420                 default:
 421                     break;
 422                 }
 423                 if (!ASN1_bn_print(bp, "", bn, NULL, off))
 424                     goto err;
 425             }
 426         }
 427     }
 428     if (pkey_is_pss(pkey) && !rsa_pss_param_print(bp, 1, x->pss, off))
 429         goto err;
 430     ret = 1;
 431  err:
 432     return ret;
 433 }
 434
 435 static int rsa_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 436                          ASN1_PCTX *ctx)
 437 {
 438     return pkey_rsa_print(bp, pkey, indent, 0);
 439 }
 440
 441 static int rsa_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 442                           ASN1_PCTX *ctx)
 443 {
 444     return pkey_rsa_print(bp, pkey, indent, 1);
 445 }
 446
 447 static RSA_PSS_PARAMS *rsa_pss_decode(const X509_ALGOR *alg)
 448 {
 449     RSA_PSS_PARAMS *pss;
 450
 451     pss = ASN1_TYPE_unpack_sequence(ASN1_ITEM_rptr(RSA_PSS_PARAMS),
 452                                     alg->parameter);
 453
 454     if (pss == NULL)
 455         return NULL;
 456
 457     if (pss->maskGenAlgorithm != NULL) {
 458         pss->maskHash = x509_algor_mgf1_decode(pss->maskGenAlgorithm);
 459         if (pss->maskHash == NULL) {
 460             RSA_PSS_PARAMS_free(pss);
 461             return NULL;
 462         }
 463     }
 464
 465     return pss;
 466 }
 467
 468 static int rsa_sig_print(BIO *bp, const X509_ALGOR *sigalg,
 469                          const ASN1_STRING *sig, int indent, ASN1_PCTX *pctx)
 470 {
 471     if (OBJ_obj2nid(sigalg->algorithm) == EVP_PKEY_RSA_PSS) {
 472         int rv;
 473         RSA_PSS_PARAMS *pss = rsa_pss_decode(sigalg);
 474
 475         rv = rsa_pss_param_print(bp, 0, pss, indent);
 476         RSA_PSS_PARAMS_free(pss);
 477         if (!rv)
 478             return 0;
 479     } else if (BIO_puts(bp, "\n") <= 0) {
 480         return 0;
 481     }
 482     if (sig)
 483         return X509_signature_dump(bp, sig, indent);
 484     return 1;
 485 }
 486
 487 static int rsa_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 488 {
 489     X509_ALGOR *alg = NULL;
 490     const EVP_MD *md;
 491     const EVP_MD *mgf1md;
 492     int min_saltlen;
 493
 494     switch (op) {
 495     case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
 496         if (pkey->pkey.rsa->pss != NULL) {
 497             if (!rsa_pss_get_param(pkey->pkey.rsa->pss, &md, &mgf1md,
 498                                    &min_saltlen)) {
 499                 ERR_raise(ERR_LIB_RSA, ERR_R_INTERNAL_ERROR);
 500                 return 0;
 501             }
 502             *(int *)arg2 = EVP_MD_type(md);
 503             /* Return of 2 indicates this MD is mandatory */
 504             return 2;
 505         }
 506         *(int *)arg2 = NID_sha256;
 507         return 1;
 508
 509     default:
 510         return -2;
 511
 512     }
 513
 514     if (alg)
 515         X509_ALGOR_set0(alg, OBJ_nid2obj(NID_rsaEncryption), V_ASN1_NULL, 0);
 516
 517     return 1;
 518
 519 }
 520
 521 /*
 522  * Convert EVP_PKEY_CTX in PSS mode into corresponding algorithm parameter,
 523  * suitable for setting an AlgorithmIdentifier.
 524  */
 525
 526 static RSA_PSS_PARAMS *rsa_ctx_to_pss(EVP_PKEY_CTX *pkctx)
 527 {
 528     const EVP_MD *sigmd, *mgf1md;
 529     EVP_PKEY *pk = EVP_PKEY_CTX_get0_pkey(pkctx);
 530     int saltlen;
 531
 532     if (EVP_PKEY_CTX_get_signature_md(pkctx, &sigmd) <= 0)
 533         return NULL;
 534     if (EVP_PKEY_CTX_get_rsa_mgf1_md(pkctx, &mgf1md) <= 0)
 535         return NULL;
 536     if (!EVP_PKEY_CTX_get_rsa_pss_saltlen(pkctx, &saltlen))
 537         return NULL;
 538     if (saltlen == -1) {
 539         saltlen = EVP_MD_size(sigmd);
 540     } else if (saltlen == -2 || saltlen == -3) {
 541         saltlen = EVP_PKEY_size(pk) - EVP_MD_size(sigmd) - 2;
 542         if ((EVP_PKEY_bits(pk) & 0x7) == 1)
 543             saltlen--;
 544         if (saltlen < 0)
 545             return NULL;
 546     }
 547
 548     return rsa_pss_params_create(sigmd, mgf1md, saltlen);
 549 }
 550
 551 RSA_PSS_PARAMS *rsa_pss_params_create(const EVP_MD *sigmd,
 552                                       const EVP_MD *mgf1md, int saltlen)
 553 {
 554     RSA_PSS_PARAMS *pss = RSA_PSS_PARAMS_new();
 555
 556     if (pss == NULL)
 557         goto err;
 558     if (saltlen != 20) {
 559         pss->saltLength = ASN1_INTEGER_new();
 560         if (pss->saltLength == NULL)
 561             goto err;
 562         if (!ASN1_INTEGER_set(pss->saltLength, saltlen))
 563             goto err;
 564     }
 565     if (!x509_algor_new_from_md(&pss->hashAlgorithm, sigmd))
 566         goto err;
 567     if (mgf1md == NULL)
 568         mgf1md = sigmd;
 569     if (!x509_algor_md_to_mgf1(&pss->maskGenAlgorithm, mgf1md))
 570         goto err;
 571     if (!x509_algor_new_from_md(&pss->maskHash, mgf1md))
 572         goto err;
 573     return pss;
 574  err:
 575     RSA_PSS_PARAMS_free(pss);
 576     return NULL;
 577 }
 578
 579 ASN1_STRING *ossl_rsa_ctx_to_pss_string(EVP_PKEY_CTX *pkctx)
 580 {
 581     RSA_PSS_PARAMS *pss = rsa_ctx_to_pss(pkctx);
 582     ASN1_STRING *os;
 583
 584     if (pss == NULL)
 585         return NULL;
 586
 587     os = ASN1_item_pack(pss, ASN1_ITEM_rptr(RSA_PSS_PARAMS), NULL);
 588     RSA_PSS_PARAMS_free(pss);
 589     return os;
 590 }
 591
 592 /*
 593  * From PSS AlgorithmIdentifier set public key parameters. If pkey isn't NULL
 594  * then the EVP_MD_CTX is setup and initialised. If it is NULL parameters are
 595  * passed to pkctx instead.
 596  */
 597
 598 int ossl_rsa_pss_to_ctx(EVP_MD_CTX *ctx, EVP_PKEY_CTX *pkctx,
 599                         const X509_ALGOR *sigalg, EVP_PKEY *pkey)
 600 {
 601     int rv = -1;
 602     int saltlen;
 603     const EVP_MD *mgf1md = NULL, *md = NULL;
 604     RSA_PSS_PARAMS *pss;
 605
 606     /* Sanity check: make sure it is PSS */
 607     if (OBJ_obj2nid(sigalg->algorithm) != EVP_PKEY_RSA_PSS) {
 608         ERR_raise(ERR_LIB_RSA, RSA_R_UNSUPPORTED_SIGNATURE_TYPE);
 609         return -1;
 610     }
 611     /* Decode PSS parameters */
 612     pss = rsa_pss_decode(sigalg);
 613
 614     if (!rsa_pss_get_param(pss, &md, &mgf1md, &saltlen)) {
 615         ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_PSS_PARAMETERS);
 616         goto err;
 617     }
 618
 619     /* We have all parameters now set up context */
 620     if (pkey) {
 621         if (!EVP_DigestVerifyInit(ctx, &pkctx, md, NULL, pkey))
 622             goto err;
 623     } else {
 624         const EVP_MD *checkmd;
 625         if (EVP_PKEY_CTX_get_signature_md(pkctx, &checkmd) <= 0)
 626             goto err;
 627         if (EVP_MD_type(md) != EVP_MD_type(checkmd)) {
 628             ERR_raise(ERR_LIB_RSA, RSA_R_DIGEST_DOES_NOT_MATCH);
 629             goto err;
 630         }
 631     }
 632
 633     if (EVP_PKEY_CTX_set_rsa_padding(pkctx, RSA_PKCS1_PSS_PADDING) <= 0)
 634         goto err;
 635
 636     if (EVP_PKEY_CTX_set_rsa_pss_saltlen(pkctx, saltlen) <= 0)
 637         goto err;
 638
 639     if (EVP_PKEY_CTX_set_rsa_mgf1_md(pkctx, mgf1md) <= 0)
 640         goto err;
 641     /* Carry on */
 642     rv = 1;
 643
 644  err:
 645     RSA_PSS_PARAMS_free(pss);
 646     return rv;
 647 }
 648
 649 static int rsa_pss_verify_param(const EVP_MD **pmd, const EVP_MD **pmgf1md,
 650                                 int *psaltlen, int *ptrailerField)
 651 {
 652     if (psaltlen != NULL && *psaltlen < 0) {
 653         ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_SALT_LENGTH);
 654         return 0;
 655     }
 656     /*
 657      * low-level routines support only trailer field 0xbc (value 1) and
 658      * PKCS#1 says we should reject any other value anyway.
 659      */
 660     if (ptrailerField != NULL && *ptrailerField != 1) {
 661         ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_TRAILER);
 662         return 0;
 663     }
 664     return 1;
 665 }
 666
 667 static int rsa_pss_get_param_unverified(const RSA_PSS_PARAMS *pss,
 668                                         const EVP_MD **pmd,
 669                                         const EVP_MD **pmgf1md,
 670                                         int *psaltlen, int *ptrailerField)
 671 {
 672     RSA_PSS_PARAMS_30 pss_params;
 673
 674     /* Get the defaults from the ONE place */
 675     (void)ossl_rsa_pss_params_30_set_defaults(&pss_params);
 676
 677     if (pss == NULL)
 678         return 0;
 679     *pmd = x509_algor_get_md(pss->hashAlgorithm);
 680     if (*pmd == NULL)
 681         return 0;
 682     *pmgf1md = x509_algor_get_md(pss->maskHash);
 683     if (*pmgf1md == NULL)
 684         return 0;
 685     if (pss->saltLength)
 686         *psaltlen = ASN1_INTEGER_get(pss->saltLength);
 687     else
 688         *psaltlen = ossl_rsa_pss_params_30_saltlen(&pss_params);
 689     if (pss->trailerField)
 690         *ptrailerField = ASN1_INTEGER_get(pss->trailerField);
 691     else
 692         *ptrailerField = ossl_rsa_pss_params_30_trailerfield(&pss_params);;
 693
 694     return 1;
 695 }
 696
 697 int rsa_pss_get_param(const RSA_PSS_PARAMS *pss, const EVP_MD **pmd,
 698                       const EVP_MD **pmgf1md, int *psaltlen)
 699 {
 700     /*
 701      * Callers do not care about the trailer field, and yet, we must
 702      * pass it from get_param to verify_param, since the latter checks
 703      * its value.
 704      *
 705      * When callers start caring, it's a simple thing to add another
 706      * argument to this function.
 707      */
 708     int trailerField = 0;
 709
 710     return rsa_pss_get_param_unverified(pss, pmd, pmgf1md, psaltlen,
 711                                         &trailerField)
 712         && rsa_pss_verify_param(pmd, pmgf1md, psaltlen, &trailerField);
 713 }
 714
 715 static int rsa_sync_to_pss_params_30(RSA *rsa)
 716 {
 717     if (rsa != NULL && rsa->pss != NULL) {
 718         const EVP_MD *md = NULL, *mgf1md = NULL;
 719         int md_nid, mgf1md_nid, saltlen, trailerField;
 720         RSA_PSS_PARAMS_30 pss_params;
 721
 722         /*
 723          * We don't care about the validity of the fields here, we just
 724          * want to synchronise values.  Verifying here makes it impossible
 725          * to even read a key with invalid values, making it hard to test
 726          * a bad situation.
 727          *
 728          * Other routines use rsa_pss_get_param(), so the values will be
 729          * checked, eventually.
 730          */
 731         if (!rsa_pss_get_param_unverified(rsa->pss, &md, &mgf1md,
 732                                           &saltlen, &trailerField))
 733             return 0;
 734         md_nid = EVP_MD_type(md);
 735         mgf1md_nid = EVP_MD_type(mgf1md);
 736         if (!ossl_rsa_pss_params_30_set_defaults(&pss_params)
 737             || !ossl_rsa_pss_params_30_set_hashalg(&pss_params, md_nid)
 738             || !ossl_rsa_pss_params_30_set_maskgenhashalg(&pss_params,
 739                                                           mgf1md_nid)
 740             || !ossl_rsa_pss_params_30_set_saltlen(&pss_params, saltlen)
 741             || !ossl_rsa_pss_params_30_set_trailerfield(&pss_params,
 742                                                         trailerField))
 743             return 0;
 744         rsa->pss_params = pss_params;
 745     }
 746     return 1;
 747 }
 748
 749 /*
 750  * Customised RSA item verification routine. This is called when a signature
 751  * is encountered requiring special handling. We currently only handle PSS.
 752  */
 753
 754 static int rsa_item_verify(EVP_MD_CTX *ctx, const ASN1_ITEM *it,
 755                            const void *asn, const X509_ALGOR *sigalg,
 756                            const ASN1_BIT_STRING *sig, EVP_PKEY *pkey)
 757 {
 758     /* Sanity check: make sure it is PSS */
 759     if (OBJ_obj2nid(sigalg->algorithm) != EVP_PKEY_RSA_PSS) {
 760         ERR_raise(ERR_LIB_RSA, RSA_R_UNSUPPORTED_SIGNATURE_TYPE);
 761         return -1;
 762     }
 763     if (ossl_rsa_pss_to_ctx(ctx, NULL, sigalg, pkey) > 0) {
 764         /* Carry on */
 765         return 2;
 766     }
 767     return -1;
 768 }
 769
 770 static int rsa_item_sign(EVP_MD_CTX *ctx, const ASN1_ITEM *it, const void *asn,
 771                          X509_ALGOR *alg1, X509_ALGOR *alg2,
 772                          ASN1_BIT_STRING *sig)
 773 {
 774     int pad_mode;
 775     EVP_PKEY_CTX *pkctx = EVP_MD_CTX_pkey_ctx(ctx);
 776
 777     if (EVP_PKEY_CTX_get_rsa_padding(pkctx, &pad_mode) <= 0)
 778         return 0;
 779     if (pad_mode == RSA_PKCS1_PADDING)
 780         return 2;
 781     if (pad_mode == RSA_PKCS1_PSS_PADDING) {
 782         ASN1_STRING *os1 = NULL;
 783         os1 = ossl_rsa_ctx_to_pss_string(pkctx);
 784         if (!os1)
 785             return 0;
 786         /* Duplicate parameters if we have to */
 787         if (alg2) {
 788             ASN1_STRING *os2 = ASN1_STRING_dup(os1);
 789             if (!os2) {
 790                 ASN1_STRING_free(os1);
 791                 return 0;
 792             }
 793             X509_ALGOR_set0(alg2, OBJ_nid2obj(EVP_PKEY_RSA_PSS),
 794                             V_ASN1_SEQUENCE, os2);
 795         }
 796         X509_ALGOR_set0(alg1, OBJ_nid2obj(EVP_PKEY_RSA_PSS),
 797                         V_ASN1_SEQUENCE, os1);
 798         return 3;
 799     }
 800     return 2;
 801 }
 802
 803 static int rsa_sig_info_set(X509_SIG_INFO *siginf, const X509_ALGOR *sigalg,
 804                             const ASN1_STRING *sig)
 805 {
 806     int rv = 0;
 807     int mdnid, saltlen;
 808     uint32_t flags;
 809     const EVP_MD *mgf1md = NULL, *md = NULL;
 810     RSA_PSS_PARAMS *pss;
 811     int secbits;
 812
 813     /* Sanity check: make sure it is PSS */
 814     if (OBJ_obj2nid(sigalg->algorithm) != EVP_PKEY_RSA_PSS)
 815         return 0;
 816     /* Decode PSS parameters */
 817     pss = rsa_pss_decode(sigalg);
 818     if (!rsa_pss_get_param(pss, &md, &mgf1md, &saltlen))
 819         goto err;
 820     mdnid = EVP_MD_type(md);
 821     /*
 822      * For TLS need SHA256, SHA384 or SHA512, digest and MGF1 digest must
 823      * match and salt length must equal digest size
 824      */
 825     if ((mdnid == NID_sha256 || mdnid == NID_sha384 || mdnid == NID_sha512)
 826             && mdnid == EVP_MD_type(mgf1md) && saltlen == EVP_MD_size(md))
 827         flags = X509_SIG_INFO_TLS;
 828     else
 829         flags = 0;
 830     /* Note: security bits half number of digest bits */
 831     secbits = EVP_MD_size(md) * 4;
 832     /*
 833      * SHA1 and MD5 are known to be broken. Reduce security bits so that
 834      * they're no longer accepted at security level 1. The real values don't
 835      * really matter as long as they're lower than 80, which is our security
 836      * level 1.
 837      * https://eprint.iacr.org/2020/014 puts a chosen-prefix attack for SHA1 at
 838      * 2^63.4
 839      * https://documents.epfl.ch/users/l/le/lenstra/public/papers/lat.pdf
 840      * puts a chosen-prefix attack for MD5 at 2^39.
 841      */
 842     if (mdnid == NID_sha1)
 843         secbits = 64;
 844     else if (mdnid == NID_md5_sha1)
 845         secbits = 68;
 846     else if (mdnid == NID_md5)
 847         secbits = 39;
 848     X509_SIG_INFO_set(siginf, mdnid, EVP_PKEY_RSA_PSS, secbits,
 849                       flags);
 850     rv = 1;
 851     err:
 852     RSA_PSS_PARAMS_free(pss);
 853     return rv;
 854 }
 855
 856 static int rsa_pkey_check(const EVP_PKEY *pkey)
 857 {
 858     return RSA_check_key_ex(pkey->pkey.rsa, NULL);
 859 }
 860
 861 static size_t rsa_pkey_dirty_cnt(const EVP_PKEY *pkey)
 862 {
 863     return pkey->pkey.rsa->dirty_cnt;
 864 }
 865
 866 /*
 867  * For the moment, we trust the call path, where keys going through
 868  * rsa_pkey_export_to() match a KEYMGMT for the "RSA" keytype, while
 869  * keys going through rsa_pss_pkey_export_to() match a KEYMGMT for the
 870  * "RSA-PSS" keytype.
 871  * TODO(3.0) Investigate whether we should simply continue to trust the
 872  * call path, or if we should strengthen this function by checking that
 873  * |rsa_type| matches the RSA key subtype.  The latter requires ensuring
 874  * that the type flag for the RSA key is properly set by other functions
 875  * in this file.
 876  */
 877 static int rsa_int_export_to(const EVP_PKEY *from, int rsa_type,
 878                              void *to_keydata, EVP_KEYMGMT *to_keymgmt,
 879                              OSSL_LIB_CTX *libctx, const char *propq)
 880 {
 881     RSA *rsa = from->pkey.rsa;
 882     OSSL_PARAM_BLD *tmpl = OSSL_PARAM_BLD_new();
 883     OSSL_PARAM *params = NULL;
 884     int selection = 0;
 885     int rv = 0;
 886
 887     if (tmpl == NULL)
 888         return 0;
 889     /*
 890      * If the RSA method is foreign, then we can't be sure of anything, and
 891      * can therefore not export or pretend to export.
 892      */
 893     if (RSA_get_method(rsa) != RSA_PKCS1_OpenSSL())
 894         goto err;
 895
 896     /* Public parameters must always be present */
 897     if (RSA_get0_n(rsa) == NULL || RSA_get0_e(rsa) == NULL)
 898         goto err;
 899
 900     if (!ossl_rsa_todata(rsa, tmpl, NULL))
 901         goto err;
 902
 903     selection |= OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
 904     if (RSA_get0_d(rsa) != NULL)
 905         selection |= OSSL_KEYMGMT_SELECT_PRIVATE_KEY;
 906
 907     if (rsa->pss != NULL) {
 908         const EVP_MD *md = NULL, *mgf1md = NULL;
 909         int md_nid, mgf1md_nid, saltlen, trailerfield;
 910         RSA_PSS_PARAMS_30 pss_params;
 911
 912         if (!rsa_pss_get_param_unverified(rsa->pss, &md, &mgf1md,
 913                                           &saltlen, &trailerfield))
 914             goto err;
 915         md_nid = EVP_MD_type(md);
 916         mgf1md_nid = EVP_MD_type(mgf1md);
 917         if (!ossl_rsa_pss_params_30_set_defaults(&pss_params)
 918             || !ossl_rsa_pss_params_30_set_hashalg(&pss_params, md_nid)
 919             || !ossl_rsa_pss_params_30_set_maskgenhashalg(&pss_params,
 920                                                           mgf1md_nid)
 921             || !ossl_rsa_pss_params_30_set_saltlen(&pss_params, saltlen)
 922             || !ossl_rsa_pss_params_30_todata(&pss_params, tmpl, NULL))
 923             goto err;
 924         selection |= OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS;
 925     }
 926
 927     if ((params = OSSL_PARAM_BLD_to_param(tmpl)) == NULL)
 928         goto err;
 929
 930     /* We export, the provider imports */
 931     rv = evp_keymgmt_import(to_keymgmt, to_keydata, selection, params);
 932
 933  err:
 934     OSSL_PARAM_BLD_free_params(params);
 935     OSSL_PARAM_BLD_free(tmpl);
 936     return rv;
 937 }
 938
 939 static int rsa_int_import_from(const OSSL_PARAM params[], void *vpctx,
 940                                int rsa_type)
 941 {
 942     EVP_PKEY_CTX *pctx = vpctx;
 943     EVP_PKEY *pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 944     RSA *rsa = ossl_rsa_new_with_ctx(pctx->libctx);
 945     RSA_PSS_PARAMS_30 rsa_pss_params = { 0, };
 946     int ok = 0;
 947
 948     if (rsa == NULL) {
 949         ERR_raise(ERR_LIB_DH, ERR_R_MALLOC_FAILURE);
 950         return 0;
 951     }
 952
 953     RSA_clear_flags(rsa, RSA_FLAG_TYPE_MASK);
 954     RSA_set_flags(rsa, rsa_type);
 955
 956     if (!ossl_rsa_pss_params_30_fromdata(&rsa_pss_params, params, pctx->libctx))
 957         goto err;
 958
 959     switch (rsa_type) {
 960     case RSA_FLAG_TYPE_RSA:
 961         /*
 962          * Were PSS parameters filled in?
 963          * In that case, something's wrong
 964          */
 965         if (!ossl_rsa_pss_params_30_is_unrestricted(&rsa_pss_params))
 966             goto err;
 967         break;
 968     case RSA_FLAG_TYPE_RSASSAPSS:
 969         /*
 970          * Were PSS parameters filled in?  In that case, create the old
 971          * RSA_PSS_PARAMS structure.  Otherwise, this is an unrestricted key.
 972          */
 973         if (!ossl_rsa_pss_params_30_is_unrestricted(&rsa_pss_params)) {
 974             /* Create the older RSA_PSS_PARAMS from RSA_PSS_PARAMS_30 data */
 975             int mdnid = ossl_rsa_pss_params_30_hashalg(&rsa_pss_params);
 976             int mgf1mdnid = ossl_rsa_pss_params_30_maskgenhashalg(&rsa_pss_params);
 977             int saltlen = ossl_rsa_pss_params_30_saltlen(&rsa_pss_params);
 978             const EVP_MD *md = EVP_get_digestbynid(mdnid);
 979             const EVP_MD *mgf1md = EVP_get_digestbynid(mgf1mdnid);
 980
 981             if ((rsa->pss = rsa_pss_params_create(md, mgf1md, saltlen)) == NULL)
 982                 goto err;
 983         }
 984         break;
 985     default:
 986         /* RSA key sub-types we don't know how to handle yet */
 987         goto err;
 988     }
 989
 990     if (!ossl_rsa_fromdata(rsa, params))
 991         goto err;
 992
 993     switch (rsa_type) {
 994     case RSA_FLAG_TYPE_RSA:
 995         ok = EVP_PKEY_assign_RSA(pkey, rsa);
 996         break;
 997     case RSA_FLAG_TYPE_RSASSAPSS:
 998         ok = EVP_PKEY_assign(pkey, EVP_PKEY_RSA_PSS, rsa);
 999         break;
1000     }
1001
1002  err:
1003     if (!ok)
1004         RSA_free(rsa);
1005     return ok;
1006 }
1007
1008 static int rsa_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
1009                               EVP_KEYMGMT *to_keymgmt, OSSL_LIB_CTX *libctx,
1010                               const char *propq)
1011 {
1012     return rsa_int_export_to(from, RSA_FLAG_TYPE_RSA, to_keydata,
1013                              to_keymgmt, libctx, propq);
1014 }
1015
1016 static int rsa_pss_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
1017                                   EVP_KEYMGMT *to_keymgmt, OSSL_LIB_CTX *libctx,
1018                                   const char *propq)
1019 {
1020     return rsa_int_export_to(from, RSA_FLAG_TYPE_RSASSAPSS, to_keydata,
1021                              to_keymgmt, libctx, propq);
1022 }
1023
1024 static int rsa_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
1025 {
1026     return rsa_int_import_from(params, vpctx, RSA_FLAG_TYPE_RSA);
1027 }
1028
1029 static int rsa_pss_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
1030 {
1031     return rsa_int_import_from(params, vpctx, RSA_FLAG_TYPE_RSASSAPSS);
1032 }
1033
1034 const EVP_PKEY_ASN1_METHOD rsa_asn1_meths[2] = {
1035     {
1036      EVP_PKEY_RSA,
1037      EVP_PKEY_RSA,
1038      ASN1_PKEY_SIGPARAM_NULL,
1039
1040      "RSA",
1041      "OpenSSL RSA method",
1042
1043      rsa_pub_decode,
1044      rsa_pub_encode,
1045      rsa_pub_cmp,
1046      rsa_pub_print,
1047
1048      rsa_priv_decode,
1049      rsa_priv_encode,
1050      rsa_priv_print,
1051
1052      int_rsa_size,
1053      rsa_bits,
1054      rsa_security_bits,
1055
1056      0, 0, 0, 0, 0, 0,
1057
1058      rsa_sig_print,
1059      int_rsa_free,
1060      rsa_pkey_ctrl,
1061      old_rsa_priv_decode,
1062      old_rsa_priv_encode,
1063      rsa_item_verify,
1064      rsa_item_sign,
1065      rsa_sig_info_set,
1066      rsa_pkey_check,
1067
1068      0, 0,
1069      0, 0, 0, 0,
1070
1071      rsa_pkey_dirty_cnt,
1072      rsa_pkey_export_to,
1073      rsa_pkey_import_from
1074     },
1075
1076     {
1077      EVP_PKEY_RSA2,
1078      EVP_PKEY_RSA,
1079      ASN1_PKEY_ALIAS}
1080 };
1081
1082 const EVP_PKEY_ASN1_METHOD rsa_pss_asn1_meth = {
1083      EVP_PKEY_RSA_PSS,
1084      EVP_PKEY_RSA_PSS,
1085      ASN1_PKEY_SIGPARAM_NULL,
1086
1087      "RSA-PSS",
1088      "OpenSSL RSA-PSS method",
1089
1090      rsa_pub_decode,
1091      rsa_pub_encode,
1092      rsa_pub_cmp,
1093      rsa_pub_print,
1094
1095      rsa_priv_decode,
1096      rsa_priv_encode,
1097      rsa_priv_print,
1098
1099      int_rsa_size,
1100      rsa_bits,
1101      rsa_security_bits,
1102
1103      0, 0, 0, 0, 0, 0,
1104
1105      rsa_sig_print,
1106      int_rsa_free,
1107      rsa_pkey_ctrl,
1108      0, 0,
1109      rsa_item_verify,
1110      rsa_item_sign,
1111      rsa_sig_info_set,
1112      rsa_pkey_check,
1113
1114      0, 0,
1115      0, 0, 0, 0,
1116
1117      rsa_pkey_dirty_cnt,
1118      rsa_pss_pkey_export_to,
1119      rsa_pss_pkey_import_from
1120 };