providers/implementations/asymciphers/rsa_enc.c

   1 /*
   2  * Copyright 2019 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 <openssl/crypto.h>
  11 #include <openssl/evp.h>
  12 #include <openssl/core_numbers.h>
  13 #include <openssl/core_names.h>
  14 #include <openssl/rsa.h>
  15 #include <openssl/params.h>
  16 #include <openssl/err.h>
  17 /* Just for SSL_MAX_MASTER_KEY_LENGTH */
  18 #include <openssl/ssl.h>
  19 #include "internal/constant_time.h"
  20 #include "internal/sizes.h"
  21 #include "crypto/rsa.h"
  22 #include "prov/providercommonerr.h"
  23 #include "prov/provider_ctx.h"
  24 #include "prov/implementations.h"
  25
  26 #include <stdlib.h>
  27
  28 static OSSL_OP_asym_cipher_newctx_fn rsa_newctx;
  29 static OSSL_OP_asym_cipher_encrypt_init_fn rsa_init;
  30 static OSSL_OP_asym_cipher_encrypt_fn rsa_encrypt;
  31 static OSSL_OP_asym_cipher_decrypt_init_fn rsa_init;
  32 static OSSL_OP_asym_cipher_decrypt_fn rsa_decrypt;
  33 static OSSL_OP_asym_cipher_freectx_fn rsa_freectx;
  34 static OSSL_OP_asym_cipher_dupctx_fn rsa_dupctx;
  35 static OSSL_OP_asym_cipher_get_ctx_params_fn rsa_get_ctx_params;
  36 static OSSL_OP_asym_cipher_gettable_ctx_params_fn rsa_gettable_ctx_params;
  37 static OSSL_OP_asym_cipher_set_ctx_params_fn rsa_set_ctx_params;
  38 static OSSL_OP_asym_cipher_settable_ctx_params_fn rsa_settable_ctx_params;
  39
  40
  41 /*
  42  * What's passed as an actual key is defined by the KEYMGMT interface.
  43  * We happen to know that our KEYMGMT simply passes RSA structures, so
  44  * we use that here too.
  45  */
  46
  47 typedef struct {
  48     OPENSSL_CTX *libctx;
  49     RSA *rsa;
  50     int pad_mode;
  51     /* OAEP message digest */
  52     EVP_MD *oaep_md;
  53     /* message digest for MGF1 */
  54     EVP_MD *mgf1_md;
  55     /* OAEP label */
  56     unsigned char *oaep_label;
  57     size_t oaep_labellen;
  58     /* TLS padding */
  59     unsigned int client_version;
  60     unsigned int alt_version;
  61 } PROV_RSA_CTX;
  62
  63 static void *rsa_newctx(void *provctx)
  64 {
  65     PROV_RSA_CTX *prsactx =  OPENSSL_zalloc(sizeof(PROV_RSA_CTX));
  66
  67     if (prsactx == NULL)
  68         return NULL;
  69     prsactx->libctx = PROV_LIBRARY_CONTEXT_OF(provctx);
  70
  71     return prsactx;
  72 }
  73
  74 static int rsa_init(void *vprsactx, void *vrsa)
  75 {
  76     PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
  77
  78     if (prsactx == NULL || vrsa == NULL || !RSA_up_ref(vrsa))
  79         return 0;
  80     RSA_free(prsactx->rsa);
  81     prsactx->rsa = vrsa;
  82     prsactx->pad_mode = RSA_PKCS1_PADDING;
  83     return 1;
  84 }
  85
  86 static int rsa_encrypt(void *vprsactx, unsigned char *out, size_t *outlen,
  87                        size_t outsize, const unsigned char *in, size_t inlen)
  88 {
  89     PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
  90     int ret;
  91
  92     if (out == NULL) {
  93         size_t len = RSA_size(prsactx->rsa);
  94
  95         if (len == 0) {
  96             ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY);
  97             return 0;
  98         }
  99         *outlen = len;
 100         return 1;
 101     }
 102
 103     if (prsactx->pad_mode == RSA_PKCS1_OAEP_PADDING) {
 104         int rsasize = RSA_size(prsactx->rsa);
 105         unsigned char *tbuf;
 106
 107         if ((tbuf = OPENSSL_malloc(rsasize)) == NULL) {
 108             PROVerr(0, ERR_R_MALLOC_FAILURE);
 109             return 0;
 110         }
 111         ret = RSA_padding_add_PKCS1_OAEP_mgf1(tbuf, rsasize, in, inlen,
 112                                               prsactx->oaep_label,
 113                                               prsactx->oaep_labellen,
 114                                               prsactx->oaep_md,
 115                                               prsactx->mgf1_md);
 116
 117         if (!ret) {
 118             OPENSSL_free(tbuf);
 119             return 0;
 120         }
 121         ret = RSA_public_encrypt(rsasize, tbuf, out, prsactx->rsa,
 122                                  RSA_NO_PADDING);
 123         OPENSSL_free(tbuf);
 124     } else {
 125         ret = RSA_public_encrypt(inlen, in, out, prsactx->rsa,
 126                                  prsactx->pad_mode);
 127     }
 128     /* A ret value of 0 is not an error */
 129     if (ret < 0)
 130         return ret;
 131     *outlen = ret;
 132     return 1;
 133 }
 134
 135 static int rsa_decrypt(void *vprsactx, unsigned char *out, size_t *outlen,
 136                        size_t outsize, const unsigned char *in, size_t inlen)
 137 {
 138     PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
 139     int ret;
 140     size_t len = RSA_size(prsactx->rsa);
 141
 142     if (prsactx->pad_mode == RSA_PKCS1_WITH_TLS_PADDING) {
 143         if (out == NULL) {
 144             *outlen = SSL_MAX_MASTER_KEY_LENGTH;
 145             return 1;
 146         }
 147         if (outsize < SSL_MAX_MASTER_KEY_LENGTH) {
 148             ERR_raise(ERR_LIB_PROV, PROV_R_BAD_LENGTH);
 149             return 0;
 150         }
 151     } else {
 152         if (out == NULL) {
 153             if (len == 0) {
 154                 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY);
 155                 return 0;
 156             }
 157             *outlen = len;
 158             return 1;
 159         }
 160
 161         if (outsize < len) {
 162             ERR_raise(ERR_LIB_PROV, PROV_R_BAD_LENGTH);
 163             return 0;
 164         }
 165     }
 166
 167     if (prsactx->pad_mode == RSA_PKCS1_OAEP_PADDING
 168             || prsactx->pad_mode == RSA_PKCS1_WITH_TLS_PADDING) {
 169         unsigned char *tbuf;
 170
 171         if ((tbuf = OPENSSL_malloc(len)) == NULL) {
 172             PROVerr(0, ERR_R_MALLOC_FAILURE);
 173             return 0;
 174         }
 175         ret = RSA_private_decrypt(inlen, in, tbuf, prsactx->rsa,
 176                                   RSA_NO_PADDING);
 177         /*
 178          * With no padding then, on success ret should be len, otherwise an
 179          * error occurred (non-constant time)
 180          */
 181         if (ret != (int)len) {
 182             OPENSSL_free(tbuf);
 183             ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_DECRYPT);
 184             return 0;
 185         }
 186         if (prsactx->pad_mode == RSA_PKCS1_OAEP_PADDING) {
 187             ret = RSA_padding_check_PKCS1_OAEP_mgf1(out, outsize, tbuf,
 188                                                     len, len,
 189                                                     prsactx->oaep_label,
 190                                                     prsactx->oaep_labellen,
 191                                                     prsactx->oaep_md,
 192                                                     prsactx->mgf1_md);
 193         } else {
 194             /* RSA_PKCS1_WITH_TLS_PADDING */
 195             if (prsactx->client_version <= 0) {
 196                 ERR_raise(ERR_LIB_PROV, PROV_R_BAD_TLS_CLIENT_VERSION);
 197                 return 0;
 198             }
 199             ret = rsa_padding_check_PKCS1_type_2_TLS(out, outsize,
 200                                                      tbuf, len,
 201                                                      prsactx->client_version,
 202                                                      prsactx->alt_version);
 203         }
 204         OPENSSL_free(tbuf);
 205     } else {
 206         ret = RSA_private_decrypt(inlen, in, out, prsactx->rsa,
 207                                   prsactx->pad_mode);
 208     }
 209     *outlen = constant_time_select_s(constant_time_msb_s(ret), *outlen, ret);
 210     ret = constant_time_select_int(constant_time_msb(ret), 0, 1);
 211     return ret;
 212 }
 213
 214 static void rsa_freectx(void *vprsactx)
 215 {
 216     PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
 217
 218     RSA_free(prsactx->rsa);
 219
 220     EVP_MD_free(prsactx->oaep_md);
 221     EVP_MD_free(prsactx->mgf1_md);
 222
 223     OPENSSL_free(prsactx);
 224 }
 225
 226 static void *rsa_dupctx(void *vprsactx)
 227 {
 228     PROV_RSA_CTX *srcctx = (PROV_RSA_CTX *)vprsactx;
 229     PROV_RSA_CTX *dstctx;
 230
 231     dstctx = OPENSSL_zalloc(sizeof(*srcctx));
 232     if (dstctx == NULL)
 233         return NULL;
 234
 235     *dstctx = *srcctx;
 236     if (dstctx->rsa != NULL && !RSA_up_ref(dstctx->rsa)) {
 237         OPENSSL_free(dstctx);
 238         return NULL;
 239     }
 240
 241     if (dstctx->oaep_md != NULL && !EVP_MD_up_ref(dstctx->oaep_md)) {
 242         RSA_free(dstctx->rsa);
 243         OPENSSL_free(dstctx);
 244         return NULL;
 245     }
 246
 247     if (dstctx->mgf1_md != NULL && !EVP_MD_up_ref(dstctx->mgf1_md)) {
 248         RSA_free(dstctx->rsa);
 249         EVP_MD_free(dstctx->oaep_md);
 250         OPENSSL_free(dstctx);
 251         return NULL;
 252     }
 253
 254     return dstctx;
 255 }
 256
 257 static int rsa_get_ctx_params(void *vprsactx, OSSL_PARAM *params)
 258 {
 259     PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
 260     OSSL_PARAM *p;
 261
 262     if (prsactx == NULL || params == NULL)
 263         return 0;
 264
 265     p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_PAD_MODE);
 266     if (p != NULL && !OSSL_PARAM_set_int(p, prsactx->pad_mode))
 267         return 0;
 268
 269     p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST);
 270     if (p != NULL && !OSSL_PARAM_set_utf8_string(p, prsactx->oaep_md == NULL
 271                                                     ? ""
 272                                                     : EVP_MD_name(prsactx->oaep_md)))
 273         return 0;
 274
 275     p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST);
 276     if (p != NULL) {
 277         EVP_MD *mgf1_md = prsactx->mgf1_md == NULL ? prsactx->oaep_md
 278                                                    : prsactx->mgf1_md;
 279
 280         if (!OSSL_PARAM_set_utf8_string(p, mgf1_md == NULL
 281                                            ? ""
 282                                            : EVP_MD_name(mgf1_md)))
 283         return 0;
 284     }
 285
 286     p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL);
 287     if (p != NULL && !OSSL_PARAM_set_octet_ptr(p, prsactx->oaep_label, 0))
 288         return 0;
 289
 290     p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL_LEN);
 291     if (p != NULL && !OSSL_PARAM_set_size_t(p, prsactx->oaep_labellen))
 292         return 0;
 293
 294     p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION);
 295     if (p != NULL && !OSSL_PARAM_set_uint(p, prsactx->client_version))
 296         return 0;
 297
 298     p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION);
 299     if (p != NULL && !OSSL_PARAM_set_uint(p, prsactx->alt_version))
 300         return 0;
 301
 302     return 1;
 303 }
 304
 305 static const OSSL_PARAM known_gettable_ctx_params[] = {
 306     OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST, NULL, 0),
 307     OSSL_PARAM_int(OSSL_ASYM_CIPHER_PARAM_PAD_MODE, NULL),
 308     OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST, NULL, 0),
 309     OSSL_PARAM_DEFN(OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL, OSSL_PARAM_OCTET_PTR,
 310                     NULL, 0),
 311     OSSL_PARAM_size_t(OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL_LEN, NULL),
 312     OSSL_PARAM_uint(OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION, NULL),
 313     OSSL_PARAM_uint(OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION, NULL),
 314     OSSL_PARAM_END
 315 };
 316
 317 static const OSSL_PARAM *rsa_gettable_ctx_params(void)
 318 {
 319     return known_gettable_ctx_params;
 320 }
 321
 322 static int rsa_set_ctx_params(void *vprsactx, const OSSL_PARAM params[])
 323 {
 324     PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
 325     const OSSL_PARAM *p;
 326     char mdname[OSSL_MAX_NAME_SIZE];
 327     char mdprops[OSSL_MAX_PROPQUERY_SIZE] = { '\0' };
 328     char *str = mdname;
 329     int pad_mode;
 330
 331     if (prsactx == NULL || params == NULL)
 332         return 0;
 333
 334     p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST);
 335     if (p != NULL) {
 336         if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(mdname)))
 337             return 0;
 338
 339         str = mdprops;
 340         p = OSSL_PARAM_locate_const(params,
 341                                     OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST_PROPS);
 342         if (p != NULL) {
 343             if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(mdprops)))
 344                 return 0;
 345         }
 346
 347         EVP_MD_free(prsactx->oaep_md);
 348         prsactx->oaep_md = EVP_MD_fetch(prsactx->libctx, mdname, mdprops);
 349
 350         if (prsactx->oaep_md == NULL)
 351             return 0;
 352     }
 353
 354     p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_PAD_MODE);
 355     if (p != NULL) {
 356         if (!OSSL_PARAM_get_int(p, &pad_mode))
 357             return 0;
 358         /*
 359          * PSS padding is for signatures only so is not compatible with
 360          * asymmetric cipher use.
 361          */
 362         if (pad_mode == RSA_PKCS1_PSS_PADDING)
 363             return 0;
 364         if (pad_mode == RSA_PKCS1_OAEP_PADDING && prsactx->oaep_md == NULL) {
 365             prsactx->oaep_md = EVP_MD_fetch(prsactx->libctx, "SHA1", mdprops);
 366             if (prsactx->oaep_md == NULL)
 367                 return 0;
 368         }
 369         prsactx->pad_mode = pad_mode;
 370     }
 371
 372     p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST);
 373     if (p != NULL) {
 374         if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(mdname)))
 375             return 0;
 376
 377         str = mdprops;
 378         p = OSSL_PARAM_locate_const(params,
 379                                     OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST_PROPS);
 380         if (p != NULL) {
 381             if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(mdprops)))
 382                 return 0;
 383         } else {
 384             str = NULL;
 385         }
 386
 387         EVP_MD_free(prsactx->mgf1_md);
 388         prsactx->mgf1_md = EVP_MD_fetch(prsactx->libctx, mdname, str);
 389
 390         if (prsactx->mgf1_md == NULL)
 391             return 0;
 392     }
 393
 394     p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL);
 395     if (p != NULL) {
 396         void *tmp_label = NULL;
 397         size_t tmp_labellen;
 398
 399         if (!OSSL_PARAM_get_octet_string(p, &tmp_label, 0, &tmp_labellen))
 400             return 0;
 401         OPENSSL_free(prsactx->oaep_label);
 402         prsactx->oaep_label = (unsigned char *)tmp_label;
 403         prsactx->oaep_labellen = tmp_labellen;
 404     }
 405
 406     p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION);
 407     if (p != NULL) {
 408         unsigned int client_version;
 409
 410         if (!OSSL_PARAM_get_uint(p, &client_version))
 411             return 0;
 412         prsactx->client_version = client_version;
 413     }
 414
 415     p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION);
 416     if (p != NULL) {
 417         unsigned int alt_version;
 418
 419         if (!OSSL_PARAM_get_uint(p, &alt_version))
 420             return 0;
 421         prsactx->alt_version = alt_version;
 422     }
 423
 424     return 1;
 425 }
 426
 427 static const OSSL_PARAM known_settable_ctx_params[] = {
 428     OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST, NULL, 0),
 429     OSSL_PARAM_int(OSSL_ASYM_CIPHER_PARAM_PAD_MODE, NULL),
 430     OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST, NULL, 0),
 431     OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST_PROPS, NULL, 0),
 432     OSSL_PARAM_octet_string(OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL, NULL, 0),
 433     OSSL_PARAM_uint(OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION, NULL),
 434     OSSL_PARAM_uint(OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION, NULL),
 435     OSSL_PARAM_END
 436 };
 437
 438 static const OSSL_PARAM *rsa_settable_ctx_params(void)
 439 {
 440     return known_settable_ctx_params;
 441 }
 442
 443 const OSSL_DISPATCH rsa_asym_cipher_functions[] = {
 444     { OSSL_FUNC_ASYM_CIPHER_NEWCTX, (void (*)(void))rsa_newctx },
 445     { OSSL_FUNC_ASYM_CIPHER_ENCRYPT_INIT, (void (*)(void))rsa_init },
 446     { OSSL_FUNC_ASYM_CIPHER_ENCRYPT, (void (*)(void))rsa_encrypt },
 447     { OSSL_FUNC_ASYM_CIPHER_DECRYPT_INIT, (void (*)(void))rsa_init },
 448     { OSSL_FUNC_ASYM_CIPHER_DECRYPT, (void (*)(void))rsa_decrypt },
 449     { OSSL_FUNC_ASYM_CIPHER_FREECTX, (void (*)(void))rsa_freectx },
 450     { OSSL_FUNC_ASYM_CIPHER_DUPCTX, (void (*)(void))rsa_dupctx },
 451     { OSSL_FUNC_ASYM_CIPHER_GET_CTX_PARAMS,
 452       (void (*)(void))rsa_get_ctx_params },
 453     { OSSL_FUNC_ASYM_CIPHER_GETTABLE_CTX_PARAMS,
 454       (void (*)(void))rsa_gettable_ctx_params },
 455     { OSSL_FUNC_ASYM_CIPHER_SET_CTX_PARAMS,
 456       (void (*)(void))rsa_set_ctx_params },
 457     { OSSL_FUNC_ASYM_CIPHER_SETTABLE_CTX_PARAMS,
 458       (void (*)(void))rsa_settable_ctx_params },
 459     { 0, NULL }
 460 };