crypto/rsa/rsa_ameth.c

   1 /*
   2  * Copyright 2006-2023 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 /* Set any parameters associated with pkey */
  29 static int rsa_param_encode(const EVP_PKEY *pkey,
  30                             ASN1_STRING **pstr, int *pstrtype)
  31 {
  32     const RSA *rsa = pkey->pkey.rsa;
  33
  34     *pstr = NULL;
  35     /* If RSA it's just NULL type */
  36     if (RSA_test_flags(rsa, RSA_FLAG_TYPE_MASK) != RSA_FLAG_TYPE_RSASSAPSS) {
  37         *pstrtype = V_ASN1_NULL;
  38         return 1;
  39     }
  40     /* If no PSS parameters we omit parameters entirely */
  41     if (rsa->pss == NULL) {
  42         *pstrtype = V_ASN1_UNDEF;
  43         return 1;
  44     }
  45     /* Encode PSS parameters */
  46     if (ASN1_item_pack(rsa->pss, ASN1_ITEM_rptr(RSA_PSS_PARAMS), pstr) == NULL)
  47         return 0;
  48
  49     *pstrtype = V_ASN1_SEQUENCE;
  50     return 1;
  51 }
  52 /* Decode any parameters and set them in RSA structure */
  53 static int rsa_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
  54 {
  55     unsigned char *penc = NULL;
  56     int penclen;
  57     ASN1_STRING *str;
  58     int strtype;
  59
  60     if (!rsa_param_encode(pkey, &str, &strtype))
  61         return 0;
  62     penclen = i2d_RSAPublicKey(pkey->pkey.rsa, &penc);
  63     if (penclen <= 0)
  64         return 0;
  65     if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
  66                                strtype, str, penc, penclen))
  67         return 1;
  68
  69     OPENSSL_free(penc);
  70     return 0;
  71 }
  72
  73 static int rsa_pub_decode(EVP_PKEY *pkey, const X509_PUBKEY *pubkey)
  74 {
  75     const unsigned char *p;
  76     int pklen;
  77     X509_ALGOR *alg;
  78     RSA *rsa = NULL;
  79
  80     if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &alg, pubkey))
  81         return 0;
  82     if ((rsa = d2i_RSAPublicKey(NULL, &p, pklen)) == NULL)
  83         return 0;
  84     if (!ossl_rsa_param_decode(rsa, alg)) {
  85         RSA_free(rsa);
  86         return 0;
  87     }
  88
  89     RSA_clear_flags(rsa, RSA_FLAG_TYPE_MASK);
  90     switch (pkey->ameth->pkey_id) {
  91     case EVP_PKEY_RSA:
  92         RSA_set_flags(rsa, RSA_FLAG_TYPE_RSA);
  93         break;
  94     case EVP_PKEY_RSA_PSS:
  95         RSA_set_flags(rsa, RSA_FLAG_TYPE_RSASSAPSS);
  96         break;
  97     default:
  98         /* Leave the type bits zero */
  99         break;
 100     }
 101
 102     if (!EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, rsa)) {
 103         RSA_free(rsa);
 104         return 0;
 105     }
 106     return 1;
 107 }
 108
 109 static int rsa_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 110 {
 111     /*
 112      * Don't check the public/private key, this is mostly for smart
 113      * cards.
 114      */
 115     if (((RSA_flags(a->pkey.rsa) & RSA_METHOD_FLAG_NO_CHECK))
 116             || (RSA_flags(b->pkey.rsa) & RSA_METHOD_FLAG_NO_CHECK)) {
 117         return 1;
 118     }
 119
 120     if (BN_cmp(b->pkey.rsa->n, a->pkey.rsa->n) != 0
 121         || BN_cmp(b->pkey.rsa->e, a->pkey.rsa->e) != 0)
 122         return 0;
 123     return 1;
 124 }
 125
 126 static int old_rsa_priv_decode(EVP_PKEY *pkey,
 127                                const unsigned char **pder, int derlen)
 128 {
 129     RSA *rsa;
 130
 131     if ((rsa = d2i_RSAPrivateKey(NULL, pder, derlen)) == NULL)
 132         return 0;
 133     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, rsa);
 134     return 1;
 135 }
 136
 137 static int old_rsa_priv_encode(const EVP_PKEY *pkey, unsigned char **pder)
 138 {
 139     return i2d_RSAPrivateKey(pkey->pkey.rsa, pder);
 140 }
 141
 142 static int rsa_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 143 {
 144     unsigned char *rk = NULL;
 145     int rklen;
 146     ASN1_STRING *str;
 147     int strtype;
 148
 149     if (!rsa_param_encode(pkey, &str, &strtype))
 150         return 0;
 151     rklen = i2d_RSAPrivateKey(pkey->pkey.rsa, &rk);
 152
 153     if (rklen <= 0) {
 154         ERR_raise(ERR_LIB_RSA, ERR_R_ASN1_LIB);
 155         ASN1_STRING_free(str);
 156         return 0;
 157     }
 158
 159     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
 160                          strtype, str, rk, rklen)) {
 161         ERR_raise(ERR_LIB_RSA, ERR_R_ASN1_LIB);
 162         ASN1_STRING_free(str);
 163         OPENSSL_clear_free(rk, rklen);
 164         return 0;
 165     }
 166
 167     return 1;
 168 }
 169
 170 static int rsa_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
 171 {
 172     int ret = 0;
 173     RSA *rsa = ossl_rsa_key_from_pkcs8(p8, NULL, NULL);
 174
 175     if (rsa != NULL) {
 176         ret = 1;
 177         EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, rsa);
 178     }
 179     return ret;
 180 }
 181
 182 static int int_rsa_size(const EVP_PKEY *pkey)
 183 {
 184     return RSA_size(pkey->pkey.rsa);
 185 }
 186
 187 static int rsa_bits(const EVP_PKEY *pkey)
 188 {
 189     return BN_num_bits(pkey->pkey.rsa->n);
 190 }
 191
 192 static int rsa_security_bits(const EVP_PKEY *pkey)
 193 {
 194     return RSA_security_bits(pkey->pkey.rsa);
 195 }
 196
 197 static void int_rsa_free(EVP_PKEY *pkey)
 198 {
 199     RSA_free(pkey->pkey.rsa);
 200 }
 201
 202 static int rsa_pss_param_print(BIO *bp, int pss_key, RSA_PSS_PARAMS *pss,
 203                                int indent)
 204 {
 205     int rv = 0;
 206     X509_ALGOR *maskHash = NULL;
 207
 208     if (!BIO_indent(bp, indent, 128))
 209         goto err;
 210     if (pss_key) {
 211         if (pss == NULL) {
 212             if (BIO_puts(bp, "No PSS parameter restrictions\n") <= 0)
 213                 return 0;
 214             return 1;
 215         } else {
 216             if (BIO_puts(bp, "PSS parameter restrictions:") <= 0)
 217                 return 0;
 218         }
 219     } else if (pss == NULL) {
 220         if (BIO_puts(bp, "(INVALID PSS PARAMETERS)\n") <= 0)
 221             return 0;
 222         return 1;
 223     }
 224     if (BIO_puts(bp, "\n") <= 0)
 225         goto err;
 226     if (pss_key)
 227         indent += 2;
 228     if (!BIO_indent(bp, indent, 128))
 229         goto err;
 230     if (BIO_puts(bp, "Hash Algorithm: ") <= 0)
 231         goto err;
 232
 233     if (pss->hashAlgorithm) {
 234         if (i2a_ASN1_OBJECT(bp, pss->hashAlgorithm->algorithm) <= 0)
 235             goto err;
 236     } else if (BIO_puts(bp, "sha1 (default)") <= 0) {
 237         goto err;
 238     }
 239
 240     if (BIO_puts(bp, "\n") <= 0)
 241         goto err;
 242
 243     if (!BIO_indent(bp, indent, 128))
 244         goto err;
 245
 246     if (BIO_puts(bp, "Mask Algorithm: ") <= 0)
 247         goto err;
 248     if (pss->maskGenAlgorithm) {
 249         if (i2a_ASN1_OBJECT(bp, pss->maskGenAlgorithm->algorithm) <= 0)
 250             goto err;
 251         if (BIO_puts(bp, " with ") <= 0)
 252             goto err;
 253         maskHash = ossl_x509_algor_mgf1_decode(pss->maskGenAlgorithm);
 254         if (maskHash != NULL) {
 255             if (i2a_ASN1_OBJECT(bp, maskHash->algorithm) <= 0)
 256                 goto err;
 257         } else if (BIO_puts(bp, "INVALID") <= 0) {
 258             goto err;
 259         }
 260     } else if (BIO_puts(bp, "mgf1 with sha1 (default)") <= 0) {
 261         goto err;
 262     }
 263     BIO_puts(bp, "\n");
 264
 265     if (!BIO_indent(bp, indent, 128))
 266         goto err;
 267     if (BIO_printf(bp, "%s Salt Length: 0x", pss_key ? "Minimum" : "") <= 0)
 268         goto err;
 269     if (pss->saltLength) {
 270         if (i2a_ASN1_INTEGER(bp, pss->saltLength) <= 0)
 271             goto err;
 272     } else if (BIO_puts(bp, "14 (default)") <= 0) {
 273         goto err;
 274     }
 275     BIO_puts(bp, "\n");
 276
 277     if (!BIO_indent(bp, indent, 128))
 278         goto err;
 279     if (BIO_puts(bp, "Trailer Field: 0x") <= 0)
 280         goto err;
 281     if (pss->trailerField) {
 282         if (i2a_ASN1_INTEGER(bp, pss->trailerField) <= 0)
 283             goto err;
 284     } else if (BIO_puts(bp, "01 (default)") <= 0) {
 285         goto err;
 286     }
 287     BIO_puts(bp, "\n");
 288
 289     rv = 1;
 290
 291  err:
 292     X509_ALGOR_free(maskHash);
 293     return rv;
 294
 295 }
 296
 297 static int pkey_rsa_print(BIO *bp, const EVP_PKEY *pkey, int off, int priv)
 298 {
 299     const RSA *x = pkey->pkey.rsa;
 300     char *str;
 301     const char *s;
 302     int ret = 0, mod_len = 0, ex_primes;
 303
 304     if (x->n != NULL)
 305         mod_len = BN_num_bits(x->n);
 306     ex_primes = sk_RSA_PRIME_INFO_num(x->prime_infos);
 307
 308     if (!BIO_indent(bp, off, 128))
 309         goto err;
 310
 311     if (BIO_printf(bp, "%s ", pkey_is_pss(pkey) ?  "RSA-PSS" : "RSA") <= 0)
 312         goto err;
 313
 314     if (priv && x->d) {
 315         if (BIO_printf(bp, "Private-Key: (%d bit, %d primes)\n",
 316                        mod_len, ex_primes <= 0 ? 2 : ex_primes + 2) <= 0)
 317             goto err;
 318         str = "modulus:";
 319         s = "publicExponent:";
 320     } else {
 321         if (BIO_printf(bp, "Public-Key: (%d bit)\n", mod_len) <= 0)
 322             goto err;
 323         str = "Modulus:";
 324         s = "Exponent:";
 325     }
 326     if (!ASN1_bn_print(bp, str, x->n, NULL, off))
 327         goto err;
 328     if (!ASN1_bn_print(bp, s, x->e, NULL, off))
 329         goto err;
 330     if (priv) {
 331         int i;
 332
 333         if (!ASN1_bn_print(bp, "privateExponent:", x->d, NULL, off))
 334             goto err;
 335         if (!ASN1_bn_print(bp, "prime1:", x->p, NULL, off))
 336             goto err;
 337         if (!ASN1_bn_print(bp, "prime2:", x->q, NULL, off))
 338             goto err;
 339         if (!ASN1_bn_print(bp, "exponent1:", x->dmp1, NULL, off))
 340             goto err;
 341         if (!ASN1_bn_print(bp, "exponent2:", x->dmq1, NULL, off))
 342             goto err;
 343         if (!ASN1_bn_print(bp, "coefficient:", x->iqmp, NULL, off))
 344             goto err;
 345         for (i = 0; i < sk_RSA_PRIME_INFO_num(x->prime_infos); i++) {
 346             /* print multi-prime info */
 347             BIGNUM *bn = NULL;
 348             RSA_PRIME_INFO *pinfo;
 349             int j;
 350
 351             pinfo = sk_RSA_PRIME_INFO_value(x->prime_infos, i);
 352             for (j = 0; j < 3; j++) {
 353                 if (!BIO_indent(bp, off, 128))
 354                     goto err;
 355                 switch (j) {
 356                 case 0:
 357                     if (BIO_printf(bp, "prime%d:", i + 3) <= 0)
 358                         goto err;
 359                     bn = pinfo->r;
 360                     break;
 361                 case 1:
 362                     if (BIO_printf(bp, "exponent%d:", i + 3) <= 0)
 363                         goto err;
 364                     bn = pinfo->d;
 365                     break;
 366                 case 2:
 367                     if (BIO_printf(bp, "coefficient%d:", i + 3) <= 0)
 368                         goto err;
 369                     bn = pinfo->t;
 370                     break;
 371                 default:
 372                     break;
 373                 }
 374                 if (!ASN1_bn_print(bp, "", bn, NULL, off))
 375                     goto err;
 376             }
 377         }
 378     }
 379     if (pkey_is_pss(pkey) && !rsa_pss_param_print(bp, 1, x->pss, off))
 380         goto err;
 381     ret = 1;
 382  err:
 383     return ret;
 384 }
 385
 386 static int rsa_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 387                          ASN1_PCTX *ctx)
 388 {
 389     return pkey_rsa_print(bp, pkey, indent, 0);
 390 }
 391
 392 static int rsa_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 393                           ASN1_PCTX *ctx)
 394 {
 395     return pkey_rsa_print(bp, pkey, indent, 1);
 396 }
 397
 398 static int rsa_sig_print(BIO *bp, const X509_ALGOR *sigalg,
 399                          const ASN1_STRING *sig, int indent, ASN1_PCTX *pctx)
 400 {
 401     if (OBJ_obj2nid(sigalg->algorithm) == EVP_PKEY_RSA_PSS) {
 402         int rv;
 403         RSA_PSS_PARAMS *pss = ossl_rsa_pss_decode(sigalg);
 404
 405         rv = rsa_pss_param_print(bp, 0, pss, indent);
 406         RSA_PSS_PARAMS_free(pss);
 407         if (!rv)
 408             return 0;
 409     } else if (BIO_puts(bp, "\n") <= 0) {
 410         return 0;
 411     }
 412     if (sig)
 413         return X509_signature_dump(bp, sig, indent);
 414     return 1;
 415 }
 416
 417 static int rsa_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 418 {
 419     const EVP_MD *md;
 420     const EVP_MD *mgf1md;
 421     int min_saltlen;
 422
 423     switch (op) {
 424     case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
 425         if (pkey->pkey.rsa->pss != NULL) {
 426             if (!ossl_rsa_pss_get_param(pkey->pkey.rsa->pss, &md, &mgf1md,
 427                                         &min_saltlen)) {
 428                 ERR_raise(ERR_LIB_RSA, ERR_R_INTERNAL_ERROR);
 429                 return 0;
 430             }
 431             *(int *)arg2 = EVP_MD_get_type(md);
 432             /* Return of 2 indicates this MD is mandatory */
 433             return 2;
 434         }
 435         *(int *)arg2 = NID_sha256;
 436         return 1;
 437
 438     default:
 439         return -2;
 440     }
 441 }
 442
 443 /*
 444  * Convert EVP_PKEY_CTX in PSS mode into corresponding algorithm parameter,
 445  * suitable for setting an AlgorithmIdentifier.
 446  */
 447
 448 static RSA_PSS_PARAMS *rsa_ctx_to_pss(EVP_PKEY_CTX *pkctx)
 449 {
 450     const EVP_MD *sigmd, *mgf1md;
 451     EVP_PKEY *pk = EVP_PKEY_CTX_get0_pkey(pkctx);
 452     int saltlen;
 453     int saltlenMax = -1;
 454
 455     if (EVP_PKEY_CTX_get_signature_md(pkctx, &sigmd) <= 0)
 456         return NULL;
 457     if (EVP_PKEY_CTX_get_rsa_mgf1_md(pkctx, &mgf1md) <= 0)
 458         return NULL;
 459     if (EVP_PKEY_CTX_get_rsa_pss_saltlen(pkctx, &saltlen) <= 0)
 460         return NULL;
 461     if (saltlen == RSA_PSS_SALTLEN_DIGEST) {
 462         saltlen = EVP_MD_get_size(sigmd);
 463     } else if (saltlen == RSA_PSS_SALTLEN_AUTO_DIGEST_MAX) {
 464         /* FIPS 186-4 section 5 "The RSA Digital Signature Algorithm",
 465          * subsection 5.5 "PKCS #1" says: "For RSASSA-PSS […] the length (in
 466          * bytes) of the salt (sLen) shall satisfy 0 <= sLen <= hLen, where
 467          * hLen is the length of the hash function output block (in bytes)."
 468          *
 469          * Provide a way to use at most the digest length, so that the default
 470          * does not violate FIPS 186-4. */
 471         saltlen = RSA_PSS_SALTLEN_MAX;
 472         saltlenMax = EVP_MD_get_size(sigmd);
 473     }
 474     if (saltlen == RSA_PSS_SALTLEN_MAX || saltlen == RSA_PSS_SALTLEN_AUTO) {
 475         saltlen = EVP_PKEY_get_size(pk) - EVP_MD_get_size(sigmd) - 2;
 476         if ((EVP_PKEY_get_bits(pk) & 0x7) == 1)
 477             saltlen--;
 478         if (saltlen < 0)
 479             return NULL;
 480         if (saltlenMax >= 0 && saltlen > saltlenMax)
 481             saltlen = saltlenMax;
 482     }
 483
 484     return ossl_rsa_pss_params_create(sigmd, mgf1md, saltlen);
 485 }
 486
 487 RSA_PSS_PARAMS *ossl_rsa_pss_params_create(const EVP_MD *sigmd,
 488                                            const EVP_MD *mgf1md, int saltlen)
 489 {
 490     RSA_PSS_PARAMS *pss = RSA_PSS_PARAMS_new();
 491
 492     if (pss == NULL)
 493         goto err;
 494     if (saltlen != 20) {
 495         pss->saltLength = ASN1_INTEGER_new();
 496         if (pss->saltLength == NULL)
 497             goto err;
 498         if (!ASN1_INTEGER_set(pss->saltLength, saltlen))
 499             goto err;
 500     }
 501     if (!ossl_x509_algor_new_from_md(&pss->hashAlgorithm, sigmd))
 502         goto err;
 503     if (mgf1md == NULL)
 504         mgf1md = sigmd;
 505     if (!ossl_x509_algor_md_to_mgf1(&pss->maskGenAlgorithm, mgf1md))
 506         goto err;
 507     if (!ossl_x509_algor_new_from_md(&pss->maskHash, mgf1md))
 508         goto err;
 509     return pss;
 510  err:
 511     RSA_PSS_PARAMS_free(pss);
 512     return NULL;
 513 }
 514
 515 ASN1_STRING *ossl_rsa_ctx_to_pss_string(EVP_PKEY_CTX *pkctx)
 516 {
 517     RSA_PSS_PARAMS *pss = rsa_ctx_to_pss(pkctx);
 518     ASN1_STRING *os;
 519
 520     if (pss == NULL)
 521         return NULL;
 522
 523     os = ASN1_item_pack(pss, ASN1_ITEM_rptr(RSA_PSS_PARAMS), NULL);
 524     RSA_PSS_PARAMS_free(pss);
 525     return os;
 526 }
 527
 528 /*
 529  * From PSS AlgorithmIdentifier set public key parameters. If pkey isn't NULL
 530  * then the EVP_MD_CTX is setup and initialised. If it is NULL parameters are
 531  * passed to pkctx instead.
 532  */
 533
 534 int ossl_rsa_pss_to_ctx(EVP_MD_CTX *ctx, EVP_PKEY_CTX *pkctx,
 535                         const X509_ALGOR *sigalg, EVP_PKEY *pkey)
 536 {
 537     int rv = -1;
 538     int saltlen;
 539     const EVP_MD *mgf1md = NULL, *md = NULL;
 540     RSA_PSS_PARAMS *pss;
 541
 542     /* Sanity check: make sure it is PSS */
 543     if (OBJ_obj2nid(sigalg->algorithm) != EVP_PKEY_RSA_PSS) {
 544         ERR_raise(ERR_LIB_RSA, RSA_R_UNSUPPORTED_SIGNATURE_TYPE);
 545         return -1;
 546     }
 547     /* Decode PSS parameters */
 548     pss = ossl_rsa_pss_decode(sigalg);
 549
 550     if (!ossl_rsa_pss_get_param(pss, &md, &mgf1md, &saltlen)) {
 551         ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_PSS_PARAMETERS);
 552         goto err;
 553     }
 554
 555     /* We have all parameters now set up context */
 556     if (pkey) {
 557         if (!EVP_DigestVerifyInit(ctx, &pkctx, md, NULL, pkey))
 558             goto err;
 559     } else {
 560         const EVP_MD *checkmd;
 561         if (EVP_PKEY_CTX_get_signature_md(pkctx, &checkmd) <= 0)
 562             goto err;
 563         if (EVP_MD_get_type(md) != EVP_MD_get_type(checkmd)) {
 564             ERR_raise(ERR_LIB_RSA, RSA_R_DIGEST_DOES_NOT_MATCH);
 565             goto err;
 566         }
 567     }
 568
 569     if (EVP_PKEY_CTX_set_rsa_padding(pkctx, RSA_PKCS1_PSS_PADDING) <= 0)
 570         goto err;
 571
 572     if (EVP_PKEY_CTX_set_rsa_pss_saltlen(pkctx, saltlen) <= 0)
 573         goto err;
 574
 575     if (EVP_PKEY_CTX_set_rsa_mgf1_md(pkctx, mgf1md) <= 0)
 576         goto err;
 577     /* Carry on */
 578     rv = 1;
 579
 580  err:
 581     RSA_PSS_PARAMS_free(pss);
 582     return rv;
 583 }
 584
 585 static int rsa_pss_verify_param(const EVP_MD **pmd, const EVP_MD **pmgf1md,
 586                                 int *psaltlen, int *ptrailerField)
 587 {
 588     if (psaltlen != NULL && *psaltlen < 0) {
 589         ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_SALT_LENGTH);
 590         return 0;
 591     }
 592     /*
 593      * low-level routines support only trailer field 0xbc (value 1) and
 594      * PKCS#1 says we should reject any other value anyway.
 595      */
 596     if (ptrailerField != NULL && *ptrailerField != 1) {
 597         ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_TRAILER);
 598         return 0;
 599     }
 600     return 1;
 601 }
 602
 603 int ossl_rsa_pss_get_param(const RSA_PSS_PARAMS *pss, const EVP_MD **pmd,
 604                            const EVP_MD **pmgf1md, int *psaltlen)
 605 {
 606     /*
 607      * Callers do not care about the trailer field, and yet, we must
 608      * pass it from get_param to verify_param, since the latter checks
 609      * its value.
 610      *
 611      * When callers start caring, it's a simple thing to add another
 612      * argument to this function.
 613      */
 614     int trailerField = 0;
 615
 616     return ossl_rsa_pss_get_param_unverified(pss, pmd, pmgf1md, psaltlen,
 617                                              &trailerField)
 618         && rsa_pss_verify_param(pmd, pmgf1md, psaltlen, &trailerField);
 619 }
 620
 621 /*
 622  * Customised RSA item verification routine. This is called when a signature
 623  * is encountered requiring special handling. We currently only handle PSS.
 624  */
 625
 626 static int rsa_item_verify(EVP_MD_CTX *ctx, const ASN1_ITEM *it,
 627                            const void *asn, const X509_ALGOR *sigalg,
 628                            const ASN1_BIT_STRING *sig, EVP_PKEY *pkey)
 629 {
 630     /* Sanity check: make sure it is PSS */
 631     if (OBJ_obj2nid(sigalg->algorithm) != EVP_PKEY_RSA_PSS) {
 632         ERR_raise(ERR_LIB_RSA, RSA_R_UNSUPPORTED_SIGNATURE_TYPE);
 633         return -1;
 634     }
 635     if (ossl_rsa_pss_to_ctx(ctx, NULL, sigalg, pkey) > 0) {
 636         /* Carry on */
 637         return 2;
 638     }
 639     return -1;
 640 }
 641
 642 static int rsa_item_sign(EVP_MD_CTX *ctx, const ASN1_ITEM *it, const void *asn,
 643                          X509_ALGOR *alg1, X509_ALGOR *alg2,
 644                          ASN1_BIT_STRING *sig)
 645 {
 646     int pad_mode;
 647     EVP_PKEY_CTX *pkctx = EVP_MD_CTX_get_pkey_ctx(ctx);
 648
 649     if (EVP_PKEY_CTX_get_rsa_padding(pkctx, &pad_mode) <= 0)
 650         return 0;
 651     if (pad_mode == RSA_PKCS1_PADDING)
 652         return 2;
 653     if (pad_mode == RSA_PKCS1_PSS_PADDING) {
 654         unsigned char aid[128];
 655         size_t aid_len = 0;
 656         OSSL_PARAM params[2];
 657
 658         if (evp_pkey_ctx_is_legacy(pkctx)) {
 659             /* No provider -> we cannot query it for algorithm ID. */
 660             ASN1_STRING *os1 = NULL;
 661
 662             os1 = ossl_rsa_ctx_to_pss_string(pkctx);
 663             if (os1 == NULL)
 664                 return 0;
 665             /* Duplicate parameters if we have to */
 666             if (alg2 != NULL) {
 667                 ASN1_STRING *os2 = ASN1_STRING_dup(os1);
 668
 669                 if (os2 == NULL) {
 670                     ASN1_STRING_free(os1);
 671                     return 0;
 672                 }
 673                 if (!X509_ALGOR_set0(alg2, OBJ_nid2obj(EVP_PKEY_RSA_PSS),
 674                                      V_ASN1_SEQUENCE, os2)) {
 675                     ASN1_STRING_free(os1);
 676                     ASN1_STRING_free(os2);
 677                     return 0;
 678                 }
 679             }
 680             if (!X509_ALGOR_set0(alg1, OBJ_nid2obj(EVP_PKEY_RSA_PSS),
 681                                  V_ASN1_SEQUENCE, os1)) {
 682                     ASN1_STRING_free(os1);
 683                     return 0;
 684             }
 685             return 3;
 686         }
 687
 688         params[0] = OSSL_PARAM_construct_octet_string(
 689             OSSL_SIGNATURE_PARAM_ALGORITHM_ID, aid, sizeof(aid));
 690         params[1] = OSSL_PARAM_construct_end();
 691
 692         if (EVP_PKEY_CTX_get_params(pkctx, params) <= 0)
 693             return 0;
 694         if ((aid_len = params[0].return_size) == 0)
 695             return 0;
 696
 697         if (alg1 != NULL) {
 698             const unsigned char *pp = aid;
 699
 700             if (d2i_X509_ALGOR(&alg1, &pp, aid_len) == NULL)
 701                 return 0;
 702         }
 703         if (alg2 != NULL) {
 704             const unsigned char *pp = aid;
 705
 706             if (d2i_X509_ALGOR(&alg2, &pp, aid_len) == NULL)
 707                 return 0;
 708         }
 709
 710         return 3;
 711     }
 712     return 2;
 713 }
 714
 715 static int rsa_sig_info_set(X509_SIG_INFO *siginf, const X509_ALGOR *sigalg,
 716                             const ASN1_STRING *sig)
 717 {
 718     int rv = 0;
 719     int mdnid, saltlen;
 720     uint32_t flags;
 721     const EVP_MD *mgf1md = NULL, *md = NULL;
 722     RSA_PSS_PARAMS *pss;
 723     int secbits;
 724
 725     /* Sanity check: make sure it is PSS */
 726     if (OBJ_obj2nid(sigalg->algorithm) != EVP_PKEY_RSA_PSS)
 727         return 0;
 728     /* Decode PSS parameters */
 729     pss = ossl_rsa_pss_decode(sigalg);
 730     if (!ossl_rsa_pss_get_param(pss, &md, &mgf1md, &saltlen))
 731         goto err;
 732     mdnid = EVP_MD_get_type(md);
 733     /*
 734      * For TLS need SHA256, SHA384 or SHA512, digest and MGF1 digest must
 735      * match and salt length must equal digest size
 736      */
 737     if ((mdnid == NID_sha256 || mdnid == NID_sha384 || mdnid == NID_sha512)
 738             && mdnid == EVP_MD_get_type(mgf1md)
 739             && saltlen == EVP_MD_get_size(md))
 740         flags = X509_SIG_INFO_TLS;
 741     else
 742         flags = 0;
 743     /* Note: security bits half number of digest bits */
 744     secbits = EVP_MD_get_size(md) * 4;
 745     /*
 746      * SHA1 and MD5 are known to be broken. Reduce security bits so that
 747      * they're no longer accepted at security level 1. The real values don't
 748      * really matter as long as they're lower than 80, which is our security
 749      * level 1.
 750      * https://eprint.iacr.org/2020/014 puts a chosen-prefix attack for SHA1 at
 751      * 2^63.4
 752      * https://documents.epfl.ch/users/l/le/lenstra/public/papers/lat.pdf
 753      * puts a chosen-prefix attack for MD5 at 2^39.
 754      */
 755     if (mdnid == NID_sha1)
 756         secbits = 64;
 757     else if (mdnid == NID_md5_sha1)
 758         secbits = 68;
 759     else if (mdnid == NID_md5)
 760         secbits = 39;
 761     X509_SIG_INFO_set(siginf, mdnid, EVP_PKEY_RSA_PSS, secbits,
 762                       flags);
 763     rv = 1;
 764     err:
 765     RSA_PSS_PARAMS_free(pss);
 766     return rv;
 767 }
 768
 769 static int rsa_pkey_check(const EVP_PKEY *pkey)
 770 {
 771     return RSA_check_key_ex(pkey->pkey.rsa, NULL);
 772 }
 773
 774 static size_t rsa_pkey_dirty_cnt(const EVP_PKEY *pkey)
 775 {
 776     return pkey->pkey.rsa->dirty_cnt;
 777 }
 778
 779 /*
 780  * There is no need to do RSA_test_flags(rsa, RSA_FLAG_TYPE_RSASSAPSS)
 781  * checks in this method since the caller tests EVP_KEYMGMT_is_a() first.
 782  */
 783 static int rsa_int_export_to(const EVP_PKEY *from, int rsa_type,
 784                              void *to_keydata,
 785                              OSSL_FUNC_keymgmt_import_fn *importer,
 786                              OSSL_LIB_CTX *libctx, const char *propq)
 787 {
 788     RSA *rsa = from->pkey.rsa;
 789     OSSL_PARAM_BLD *tmpl = OSSL_PARAM_BLD_new();
 790     OSSL_PARAM *params = NULL;
 791     int selection = 0;
 792     int rv = 0;
 793
 794     if (tmpl == NULL)
 795         return 0;
 796     /* Public parameters must always be present */
 797     if (RSA_get0_n(rsa) == NULL || RSA_get0_e(rsa) == NULL)
 798         goto err;
 799
 800     if (!ossl_rsa_todata(rsa, tmpl, NULL, 1))
 801         goto err;
 802
 803     selection |= OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
 804     if (RSA_get0_d(rsa) != NULL)
 805         selection |= OSSL_KEYMGMT_SELECT_PRIVATE_KEY;
 806
 807     if (rsa->pss != NULL) {
 808         const EVP_MD *md = NULL, *mgf1md = NULL;
 809         int md_nid, mgf1md_nid, saltlen, trailerfield;
 810         RSA_PSS_PARAMS_30 pss_params;
 811
 812         if (!ossl_rsa_pss_get_param_unverified(rsa->pss, &md, &mgf1md,
 813                                                &saltlen, &trailerfield))
 814             goto err;
 815         md_nid = EVP_MD_get_type(md);
 816         mgf1md_nid = EVP_MD_get_type(mgf1md);
 817         if (!ossl_rsa_pss_params_30_set_defaults(&pss_params)
 818             || !ossl_rsa_pss_params_30_set_hashalg(&pss_params, md_nid)
 819             || !ossl_rsa_pss_params_30_set_maskgenhashalg(&pss_params,
 820                                                           mgf1md_nid)
 821             || !ossl_rsa_pss_params_30_set_saltlen(&pss_params, saltlen)
 822             || !ossl_rsa_pss_params_30_todata(&pss_params, tmpl, NULL))
 823             goto err;
 824         selection |= OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS;
 825     }
 826
 827     if ((params = OSSL_PARAM_BLD_to_param(tmpl)) == NULL)
 828         goto err;
 829
 830     /* We export, the provider imports */
 831     rv = importer(to_keydata, selection, params);
 832
 833  err:
 834     OSSL_PARAM_free(params);
 835     OSSL_PARAM_BLD_free(tmpl);
 836     return rv;
 837 }
 838
 839 static int rsa_int_import_from(const OSSL_PARAM params[], void *vpctx,
 840                                int rsa_type)
 841 {
 842     EVP_PKEY_CTX *pctx = vpctx;
 843     EVP_PKEY *pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 844     RSA *rsa = ossl_rsa_new_with_ctx(pctx->libctx);
 845     RSA_PSS_PARAMS_30 rsa_pss_params = { 0, };
 846     int pss_defaults_set = 0;
 847     int ok = 0;
 848
 849     if (rsa == NULL) {
 850         ERR_raise(ERR_LIB_DH, ERR_R_RSA_LIB);
 851         return 0;
 852     }
 853
 854     RSA_clear_flags(rsa, RSA_FLAG_TYPE_MASK);
 855     RSA_set_flags(rsa, rsa_type);
 856
 857     if (!ossl_rsa_pss_params_30_fromdata(&rsa_pss_params, &pss_defaults_set,
 858                                          params, pctx->libctx))
 859         goto err;
 860
 861     switch (rsa_type) {
 862     case RSA_FLAG_TYPE_RSA:
 863         /*
 864          * Were PSS parameters filled in?
 865          * In that case, something's wrong
 866          */
 867         if (!ossl_rsa_pss_params_30_is_unrestricted(&rsa_pss_params))
 868             goto err;
 869         break;
 870     case RSA_FLAG_TYPE_RSASSAPSS:
 871         /*
 872          * Were PSS parameters filled in?  In that case, create the old
 873          * RSA_PSS_PARAMS structure.  Otherwise, this is an unrestricted key.
 874          */
 875         if (!ossl_rsa_pss_params_30_is_unrestricted(&rsa_pss_params)) {
 876             /* Create the older RSA_PSS_PARAMS from RSA_PSS_PARAMS_30 data */
 877             int mdnid = ossl_rsa_pss_params_30_hashalg(&rsa_pss_params);
 878             int mgf1mdnid = ossl_rsa_pss_params_30_maskgenhashalg(&rsa_pss_params);
 879             int saltlen = ossl_rsa_pss_params_30_saltlen(&rsa_pss_params);
 880             const EVP_MD *md = EVP_get_digestbynid(mdnid);
 881             const EVP_MD *mgf1md = EVP_get_digestbynid(mgf1mdnid);
 882
 883             if ((rsa->pss = ossl_rsa_pss_params_create(md, mgf1md,
 884                                                        saltlen)) == NULL)
 885                 goto err;
 886         }
 887         break;
 888     default:
 889         /* RSA key sub-types we don't know how to handle yet */
 890         goto err;
 891     }
 892
 893     if (!ossl_rsa_fromdata(rsa, params, 1))
 894         goto err;
 895
 896     switch (rsa_type) {
 897     case RSA_FLAG_TYPE_RSA:
 898         ok = EVP_PKEY_assign_RSA(pkey, rsa);
 899         break;
 900     case RSA_FLAG_TYPE_RSASSAPSS:
 901         ok = EVP_PKEY_assign(pkey, EVP_PKEY_RSA_PSS, rsa);
 902         break;
 903     }
 904
 905  err:
 906     if (!ok)
 907         RSA_free(rsa);
 908     return ok;
 909 }
 910
 911 static int rsa_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
 912                               OSSL_FUNC_keymgmt_import_fn *importer,
 913                               OSSL_LIB_CTX *libctx, const char *propq)
 914 {
 915     return rsa_int_export_to(from, RSA_FLAG_TYPE_RSA, to_keydata,
 916                              importer, libctx, propq);
 917 }
 918
 919 static int rsa_pss_pkey_export_to(const EVP_PKEY *from, void *to_keydata,
 920                                   OSSL_FUNC_keymgmt_import_fn *importer,
 921                                   OSSL_LIB_CTX *libctx, const char *propq)
 922 {
 923     return rsa_int_export_to(from, RSA_FLAG_TYPE_RSASSAPSS, to_keydata,
 924                              importer, libctx, propq);
 925 }
 926
 927 static int rsa_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
 928 {
 929     return rsa_int_import_from(params, vpctx, RSA_FLAG_TYPE_RSA);
 930 }
 931
 932 static int rsa_pss_pkey_import_from(const OSSL_PARAM params[], void *vpctx)
 933 {
 934     return rsa_int_import_from(params, vpctx, RSA_FLAG_TYPE_RSASSAPSS);
 935 }
 936
 937 static int rsa_pkey_copy(EVP_PKEY *to, EVP_PKEY *from)
 938 {
 939     RSA *rsa = from->pkey.rsa;
 940     RSA *dupkey = NULL;
 941     int ret;
 942
 943     if (rsa != NULL) {
 944         dupkey = ossl_rsa_dup(rsa, OSSL_KEYMGMT_SELECT_ALL);
 945         if (dupkey == NULL)
 946             return 0;
 947     }
 948
 949     ret = EVP_PKEY_assign(to, from->type, dupkey);
 950     if (!ret)
 951         RSA_free(dupkey);
 952     return ret;
 953 }
 954
 955 const EVP_PKEY_ASN1_METHOD ossl_rsa_asn1_meths[2] = {
 956     {
 957      EVP_PKEY_RSA,
 958      EVP_PKEY_RSA,
 959      ASN1_PKEY_SIGPARAM_NULL,
 960
 961      "RSA",
 962      "OpenSSL RSA method",
 963
 964      rsa_pub_decode,
 965      rsa_pub_encode,
 966      rsa_pub_cmp,
 967      rsa_pub_print,
 968
 969      rsa_priv_decode,
 970      rsa_priv_encode,
 971      rsa_priv_print,
 972
 973      int_rsa_size,
 974      rsa_bits,
 975      rsa_security_bits,
 976
 977      0, 0, 0, 0, 0, 0,
 978
 979      rsa_sig_print,
 980      int_rsa_free,
 981      rsa_pkey_ctrl,
 982      old_rsa_priv_decode,
 983      old_rsa_priv_encode,
 984      rsa_item_verify,
 985      rsa_item_sign,
 986      rsa_sig_info_set,
 987      rsa_pkey_check,
 988
 989      0, 0,
 990      0, 0, 0, 0,
 991
 992      rsa_pkey_dirty_cnt,
 993      rsa_pkey_export_to,
 994      rsa_pkey_import_from,
 995      rsa_pkey_copy
 996     },
 997
 998     {
 999      EVP_PKEY_RSA2,
1000      EVP_PKEY_RSA,
1001      ASN1_PKEY_ALIAS}
1002 };
1003
1004 const EVP_PKEY_ASN1_METHOD ossl_rsa_pss_asn1_meth = {
1005      EVP_PKEY_RSA_PSS,
1006      EVP_PKEY_RSA_PSS,
1007      ASN1_PKEY_SIGPARAM_NULL,
1008
1009      "RSA-PSS",
1010      "OpenSSL RSA-PSS method",
1011
1012      rsa_pub_decode,
1013      rsa_pub_encode,
1014      rsa_pub_cmp,
1015      rsa_pub_print,
1016
1017      rsa_priv_decode,
1018      rsa_priv_encode,
1019      rsa_priv_print,
1020
1021      int_rsa_size,
1022      rsa_bits,
1023      rsa_security_bits,
1024
1025      0, 0, 0, 0, 0, 0,
1026
1027      rsa_sig_print,
1028      int_rsa_free,
1029      rsa_pkey_ctrl,
1030      0, 0,
1031      rsa_item_verify,
1032      rsa_item_sign,
1033      rsa_sig_info_set,
1034      rsa_pkey_check,
1035
1036      0, 0,
1037      0, 0, 0, 0,
1038
1039      rsa_pkey_dirty_cnt,
1040      rsa_pss_pkey_export_to,
1041      rsa_pss_pkey_import_from,
1042      rsa_pkey_copy
1043 };