crypto/evp/digest.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 "internal/cryptlib.h"
  12 #include <openssl/objects.h>
  13 #include <openssl/evp.h>
  14 #include <openssl/engine.h>
  15 #include "internal/evp_int.h"
  16 #include "internal/provider.h"
  17 #include "evp_locl.h"
  18
  19 /* This call frees resources associated with the context */
  20 int EVP_MD_CTX_reset(EVP_MD_CTX *ctx)
  21 {
  22     if (ctx == NULL)
  23         return 1;
  24
  25     if (ctx->digest == NULL || ctx->digest->prov == NULL)
  26         goto legacy;
  27
  28     if (ctx->provctx != NULL) {
  29         if (ctx->digest->freectx != NULL)
  30             ctx->digest->freectx(ctx->provctx);
  31         ctx->provctx = NULL;
  32         EVP_MD_CTX_set_flags(ctx, EVP_MD_CTX_FLAG_CLEANED);
  33     }
  34
  35     if (ctx->pctx != NULL)
  36         goto legacy;
  37
  38     return 1;
  39
  40     /* TODO(3.0): Remove legacy code below */
  41  legacy:
  42
  43     /*
  44      * Don't assume ctx->md_data was cleaned in EVP_Digest_Final, because
  45      * sometimes only copies of the context are ever finalised.
  46      */
  47     if (ctx->digest && ctx->digest->cleanup
  48         && !EVP_MD_CTX_test_flags(ctx, EVP_MD_CTX_FLAG_CLEANED))
  49         ctx->digest->cleanup(ctx);
  50     if (ctx->digest && ctx->digest->ctx_size && ctx->md_data
  51         && !EVP_MD_CTX_test_flags(ctx, EVP_MD_CTX_FLAG_REUSE)) {
  52         OPENSSL_clear_free(ctx->md_data, ctx->digest->ctx_size);
  53     }
  54     /*
  55      * pctx should be freed by the user of EVP_MD_CTX
  56      * if EVP_MD_CTX_FLAG_KEEP_PKEY_CTX is set
  57      */
  58     if (!EVP_MD_CTX_test_flags(ctx, EVP_MD_CTX_FLAG_KEEP_PKEY_CTX))
  59         EVP_PKEY_CTX_free(ctx->pctx);
  60 #ifndef OPENSSL_NO_ENGINE
  61     ENGINE_finish(ctx->engine);
  62 #endif
  63     OPENSSL_cleanse(ctx, sizeof(*ctx));
  64
  65     return 1;
  66 }
  67
  68 EVP_MD_CTX *EVP_MD_CTX_new(void)
  69 {
  70     return OPENSSL_zalloc(sizeof(EVP_MD_CTX));
  71 }
  72
  73 void EVP_MD_CTX_free(EVP_MD_CTX *ctx)
  74 {
  75     if (ctx == NULL)
  76         return;
  77
  78     if (ctx->digest == NULL || ctx->digest->prov == NULL)
  79         goto legacy;
  80
  81     EVP_MD_CTX_reset(ctx);
  82
  83     EVP_MD_meth_free(ctx->fetched_digest);
  84     ctx->fetched_digest = NULL;
  85     ctx->digest = NULL;
  86     ctx->reqdigest = NULL;
  87
  88     OPENSSL_free(ctx);
  89     return;
  90
  91     /* TODO(3.0): Remove legacy code below */
  92  legacy:
  93     EVP_MD_CTX_reset(ctx);
  94     OPENSSL_free(ctx);
  95 }
  96
  97 int EVP_DigestInit(EVP_MD_CTX *ctx, const EVP_MD *type)
  98 {
  99     EVP_MD_CTX_reset(ctx);
 100     return EVP_DigestInit_ex(ctx, type, NULL);
 101 }
 102
 103 int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl)
 104 {
 105     EVP_MD *provmd;
 106     ENGINE *tmpimpl = NULL;
 107
 108     EVP_MD_CTX_clear_flags(ctx, EVP_MD_CTX_FLAG_CLEANED);
 109
 110     if (type != NULL)
 111         ctx->reqdigest = type;
 112
 113     /* TODO(3.0): Legacy work around code below. Remove this */
 114 #ifndef OPENSSL_NO_ENGINE
 115     /*
 116      * Whether it's nice or not, "Inits" can be used on "Final"'d contexts so
 117      * this context may already have an ENGINE! Try to avoid releasing the
 118      * previous handle, re-querying for an ENGINE, and having a
 119      * reinitialisation, when it may all be unnecessary.
 120      */
 121     if (ctx->engine && ctx->digest &&
 122         (type == NULL || (type->type == ctx->digest->type)))
 123         goto skip_to_init;
 124
 125     if (type != NULL && impl == NULL)
 126         tmpimpl = ENGINE_get_digest_engine(type->type);
 127 #endif
 128
 129     /*
 130      * If there are engines involved or if we're being used as part of
 131      * EVP_DigestSignInit then we should use legacy handling for now.
 132      */
 133     if (ctx->engine != NULL
 134             || impl != NULL
 135             || tmpimpl != NULL
 136             || ctx->pctx != NULL
 137             || (ctx->flags & EVP_MD_CTX_FLAG_NO_INIT) != 0) {
 138         if (ctx->digest == ctx->fetched_digest)
 139             ctx->digest = NULL;
 140         EVP_MD_meth_free(ctx->fetched_digest);
 141         ctx->fetched_digest = NULL;
 142         goto legacy;
 143     }
 144
 145     if (type->prov == NULL) {
 146         switch(type->type) {
 147         case NID_sha256:
 148             break;
 149         default:
 150             goto legacy;
 151         }
 152     }
 153
 154     if (ctx->digest != NULL && ctx->digest->ctx_size > 0) {
 155         OPENSSL_clear_free(ctx->md_data, ctx->digest->ctx_size);
 156         ctx->md_data = NULL;
 157     }
 158
 159     /* TODO(3.0): Start of non-legacy code below */
 160
 161     if (type->prov == NULL) {
 162         provmd = EVP_MD_fetch(NULL, OBJ_nid2sn(type->type), "");
 163         if (provmd == NULL) {
 164             EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_INITIALIZATION_ERROR);
 165             return 0;
 166         }
 167         type = provmd;
 168         EVP_MD_meth_free(ctx->fetched_digest);
 169         ctx->fetched_digest = provmd;
 170     }
 171
 172     ctx->digest = type;
 173     if (ctx->provctx == NULL) {
 174         ctx->provctx = ctx->digest->newctx();
 175         if (ctx->provctx == NULL) {
 176             EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_INITIALIZATION_ERROR);
 177             return 0;
 178         }
 179     }
 180
 181     if (ctx->digest->dinit == NULL) {
 182         EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_INITIALIZATION_ERROR);
 183         return 0;
 184     }
 185
 186     return ctx->digest->dinit(ctx->provctx);
 187
 188     /* TODO(3.0): Remove legacy code below */
 189  legacy:
 190
 191 #ifndef OPENSSL_NO_ENGINE
 192     if (type) {
 193         /*
 194          * Ensure an ENGINE left lying around from last time is cleared (the
 195          * previous check attempted to avoid this if the same ENGINE and
 196          * EVP_MD could be used).
 197          */
 198         ENGINE_finish(ctx->engine);
 199         if (impl != NULL) {
 200             if (!ENGINE_init(impl)) {
 201                 EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_INITIALIZATION_ERROR);
 202                 return 0;
 203             }
 204         } else {
 205             /* Ask if an ENGINE is reserved for this job */
 206             impl = tmpimpl;
 207         }
 208         if (impl != NULL) {
 209             /* There's an ENGINE for this job ... (apparently) */
 210             const EVP_MD *d = ENGINE_get_digest(impl, type->type);
 211
 212             if (d == NULL) {
 213                 EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_INITIALIZATION_ERROR);
 214                 ENGINE_finish(impl);
 215                 return 0;
 216             }
 217             /* We'll use the ENGINE's private digest definition */
 218             type = d;
 219             /*
 220              * Store the ENGINE functional reference so we know 'type' came
 221              * from an ENGINE and we need to release it when done.
 222              */
 223             ctx->engine = impl;
 224         } else
 225             ctx->engine = NULL;
 226     } else {
 227         if (!ctx->digest) {
 228             EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_NO_DIGEST_SET);
 229             return 0;
 230         }
 231         type = ctx->digest;
 232     }
 233 #endif
 234     if (ctx->digest != type) {
 235         if (ctx->digest && ctx->digest->ctx_size) {
 236             OPENSSL_clear_free(ctx->md_data, ctx->digest->ctx_size);
 237             ctx->md_data = NULL;
 238         }
 239         ctx->digest = type;
 240         if (!(ctx->flags & EVP_MD_CTX_FLAG_NO_INIT) && type->ctx_size) {
 241             ctx->update = type->update;
 242             ctx->md_data = OPENSSL_zalloc(type->ctx_size);
 243             if (ctx->md_data == NULL) {
 244                 EVPerr(EVP_F_EVP_DIGESTINIT_EX, ERR_R_MALLOC_FAILURE);
 245                 return 0;
 246             }
 247         }
 248     }
 249 #ifndef OPENSSL_NO_ENGINE
 250  skip_to_init:
 251 #endif
 252     if (ctx->pctx) {
 253         int r;
 254         r = EVP_PKEY_CTX_ctrl(ctx->pctx, -1, EVP_PKEY_OP_TYPE_SIG,
 255                               EVP_PKEY_CTRL_DIGESTINIT, 0, ctx);
 256         if (r <= 0 && (r != -2))
 257             return 0;
 258     }
 259     if (ctx->flags & EVP_MD_CTX_FLAG_NO_INIT)
 260         return 1;
 261     return ctx->digest->init(ctx);
 262 }
 263
 264 int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *data, size_t count)
 265 {
 266     if (count == 0)
 267         return 1;
 268
 269     if (ctx->digest == NULL || ctx->digest->prov == NULL)
 270         goto legacy;
 271
 272     if (ctx->digest->dupdate == NULL) {
 273         EVPerr(EVP_F_EVP_DIGESTUPDATE, EVP_R_UPDATE_ERROR);
 274         return 0;
 275     }
 276     return ctx->digest->dupdate(ctx->provctx, data, count);
 277
 278     /* TODO(3.0): Remove legacy code below */
 279  legacy:
 280     return ctx->update(ctx, data, count);
 281 }
 282
 283 /* The caller can assume that this removes any secret data from the context */
 284 int EVP_DigestFinal(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *size)
 285 {
 286     int ret;
 287     ret = EVP_DigestFinal_ex(ctx, md, size);
 288     EVP_MD_CTX_reset(ctx);
 289     return ret;
 290 }
 291
 292 /* The caller can assume that this removes any secret data from the context */
 293 int EVP_DigestFinal_ex(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *isize)
 294 {
 295     int ret;
 296     size_t size = 0;
 297
 298     if (ctx->digest == NULL || ctx->digest->prov == NULL)
 299         goto legacy;
 300
 301     if (ctx->digest->dfinal == NULL) {
 302         EVPerr(EVP_F_EVP_DIGESTFINAL_EX, EVP_R_FINAL_ERROR);
 303         return 0;
 304     }
 305
 306     ret = ctx->digest->dfinal(ctx->provctx, md, &size);
 307
 308     if (isize != NULL) {
 309         if (size <= UINT_MAX) {
 310             *isize = (int)size;
 311         } else {
 312             EVPerr(EVP_F_EVP_DIGESTFINAL_EX, EVP_R_FINAL_ERROR);
 313             ret = 0;
 314         }
 315     }
 316
 317     EVP_MD_CTX_reset(ctx);
 318
 319     return ret;
 320
 321     /* TODO(3.0): Remove legacy code below */
 322  legacy:
 323     OPENSSL_assert(ctx->digest->md_size <= EVP_MAX_MD_SIZE);
 324     ret = ctx->digest->final(ctx, md);
 325     if (isize != NULL)
 326         *isize = ctx->digest->md_size;
 327     if (ctx->digest->cleanup) {
 328         ctx->digest->cleanup(ctx);
 329         EVP_MD_CTX_set_flags(ctx, EVP_MD_CTX_FLAG_CLEANED);
 330     }
 331     OPENSSL_cleanse(ctx->md_data, ctx->digest->ctx_size);
 332     return ret;
 333 }
 334
 335 int EVP_DigestFinalXOF(EVP_MD_CTX *ctx, unsigned char *md, size_t size)
 336 {
 337     int ret = 0;
 338
 339     if (ctx->digest->flags & EVP_MD_FLAG_XOF
 340         && size <= INT_MAX
 341         && ctx->digest->md_ctrl(ctx, EVP_MD_CTRL_XOF_LEN, (int)size, NULL)) {
 342         ret = ctx->digest->final(ctx, md);
 343
 344         if (ctx->digest->cleanup != NULL) {
 345             ctx->digest->cleanup(ctx);
 346             EVP_MD_CTX_set_flags(ctx, EVP_MD_CTX_FLAG_CLEANED);
 347         }
 348         OPENSSL_cleanse(ctx->md_data, ctx->digest->ctx_size);
 349     } else {
 350         EVPerr(EVP_F_EVP_DIGESTFINALXOF, EVP_R_NOT_XOF_OR_INVALID_LENGTH);
 351     }
 352
 353     return ret;
 354 }
 355
 356 int EVP_MD_CTX_copy(EVP_MD_CTX *out, const EVP_MD_CTX *in)
 357 {
 358     EVP_MD_CTX_reset(out);
 359     return EVP_MD_CTX_copy_ex(out, in);
 360 }
 361
 362 int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in)
 363 {
 364     unsigned char *tmp_buf;
 365
 366     if (in == NULL || in->digest == NULL) {
 367         EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, EVP_R_INPUT_NOT_INITIALIZED);
 368         return 0;
 369     }
 370
 371     if (in->digest->prov == NULL)
 372         goto legacy;
 373
 374     if (in->digest->dupctx == NULL) {
 375         EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, EVP_R_NOT_ABLE_TO_COPY_CTX);
 376         return 0;
 377     }
 378
 379     EVP_MD_CTX_reset(out);
 380     if (out->fetched_digest != NULL)
 381         EVP_MD_meth_free(out->fetched_digest);
 382     *out = *in;
 383     /* NULL out pointers in case of error */
 384     out->pctx = NULL;
 385     out->provctx = NULL;
 386
 387     if (in->fetched_digest != NULL)
 388         EVP_MD_upref(in->fetched_digest);
 389
 390     out->provctx = in->digest->dupctx(in->provctx);
 391     if (out->provctx == NULL) {
 392         EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, EVP_R_NOT_ABLE_TO_COPY_CTX);
 393         return 0;
 394     }
 395
 396     /* copied EVP_MD_CTX should free the copied EVP_PKEY_CTX */
 397     EVP_MD_CTX_clear_flags(out, EVP_MD_CTX_FLAG_KEEP_PKEY_CTX);
 398     if (in->pctx != NULL) {
 399         out->pctx = EVP_PKEY_CTX_dup(in->pctx);
 400         if (out->pctx == NULL) {
 401             EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, EVP_R_NOT_ABLE_TO_COPY_CTX);
 402             EVP_MD_CTX_reset(out);
 403             return 0;
 404         }
 405     }
 406
 407     return 1;
 408
 409     /* TODO(3.0): Remove legacy code below */
 410  legacy:
 411 #ifndef OPENSSL_NO_ENGINE
 412     /* Make sure it's safe to copy a digest context using an ENGINE */
 413     if (in->engine && !ENGINE_init(in->engine)) {
 414         EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, ERR_R_ENGINE_LIB);
 415         return 0;
 416     }
 417 #endif
 418
 419     if (out->digest == in->digest) {
 420         tmp_buf = out->md_data;
 421         EVP_MD_CTX_set_flags(out, EVP_MD_CTX_FLAG_REUSE);
 422     } else
 423         tmp_buf = NULL;
 424     EVP_MD_CTX_reset(out);
 425     memcpy(out, in, sizeof(*out));
 426
 427     /* copied EVP_MD_CTX should free the copied EVP_PKEY_CTX */
 428     EVP_MD_CTX_clear_flags(out, EVP_MD_CTX_FLAG_KEEP_PKEY_CTX);
 429
 430     /* Null these variables, since they are getting fixed up
 431      * properly below.  Anything else may cause a memleak and/or
 432      * double free if any of the memory allocations below fail
 433      */
 434     out->md_data = NULL;
 435     out->pctx = NULL;
 436
 437     if (in->md_data && out->digest->ctx_size) {
 438         if (tmp_buf)
 439             out->md_data = tmp_buf;
 440         else {
 441             out->md_data = OPENSSL_malloc(out->digest->ctx_size);
 442             if (out->md_data == NULL) {
 443                 EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, ERR_R_MALLOC_FAILURE);
 444                 return 0;
 445             }
 446         }
 447         memcpy(out->md_data, in->md_data, out->digest->ctx_size);
 448     }
 449
 450     out->update = in->update;
 451
 452     if (in->pctx) {
 453         out->pctx = EVP_PKEY_CTX_dup(in->pctx);
 454         if (!out->pctx) {
 455             EVP_MD_CTX_reset(out);
 456             return 0;
 457         }
 458     }
 459
 460     if (out->digest->copy)
 461         return out->digest->copy(out, in);
 462
 463     return 1;
 464 }
 465
 466 int EVP_Digest(const void *data, size_t count,
 467                unsigned char *md, unsigned int *size, const EVP_MD *type,
 468                ENGINE *impl)
 469 {
 470     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 471     int ret;
 472
 473     if (ctx == NULL)
 474         return 0;
 475     EVP_MD_CTX_set_flags(ctx, EVP_MD_CTX_FLAG_ONESHOT);
 476     ret = EVP_DigestInit_ex(ctx, type, impl)
 477         && EVP_DigestUpdate(ctx, data, count)
 478         && EVP_DigestFinal_ex(ctx, md, size);
 479     EVP_MD_CTX_free(ctx);
 480
 481     return ret;
 482 }
 483
 484 int EVP_MD_CTX_ctrl(EVP_MD_CTX *ctx, int cmd, int p1, void *p2)
 485 {
 486     if (ctx->digest && ctx->digest->md_ctrl) {
 487         int ret = ctx->digest->md_ctrl(ctx, cmd, p1, p2);
 488         if (ret <= 0)
 489             return 0;
 490         return 1;
 491     }
 492     return 0;
 493 }
 494
 495 static void *evp_md_from_dispatch(int mdtype, const OSSL_DISPATCH *fns,
 496                                     OSSL_PROVIDER *prov)
 497 {
 498     EVP_MD *md = NULL;
 499     int fncnt = 0;
 500
 501     if ((md = EVP_MD_meth_new(mdtype, NID_undef)) == NULL)
 502         return NULL;
 503
 504     for (; fns->function_id != 0; fns++) {
 505         switch (fns->function_id) {
 506         case OSSL_FUNC_DIGEST_NEWCTX:
 507             if (md->newctx != NULL)
 508                 break;
 509             md->newctx = OSSL_get_OP_digest_newctx(fns);
 510             fncnt++;
 511             break;
 512         case OSSL_FUNC_DIGEST_INIT:
 513             if (md->dinit != NULL)
 514                 break;
 515             md->dinit = OSSL_get_OP_digest_init(fns);
 516             fncnt++;
 517             break;
 518         case OSSL_FUNC_DIGEST_UPDDATE:
 519             if (md->dupdate != NULL)
 520                 break;
 521             md->dupdate = OSSL_get_OP_digest_update(fns);
 522             fncnt++;
 523             break;
 524         case OSSL_FUNC_DIGEST_FINAL:
 525             if (md->dfinal != NULL)
 526                 break;
 527             md->dfinal = OSSL_get_OP_digest_final(fns);
 528             fncnt++;
 529             break;
 530         case OSSL_FUNC_DIGEST_DIGEST:
 531             if (md->digest != NULL)
 532                 break;
 533             md->digest = OSSL_get_OP_digest_digest(fns);
 534             /* We don't increment fnct for this as it is stand alone */
 535             break;
 536         case OSSL_FUNC_DIGEST_FREECTX:
 537             if (md->freectx != NULL)
 538                 break;
 539             md->freectx = OSSL_get_OP_digest_freectx(fns);
 540             fncnt++;
 541             break;
 542         case OSSL_FUNC_DIGEST_DUPCTX:
 543             if (md->dupctx != NULL)
 544                 break;
 545             md->dupctx = OSSL_get_OP_digest_dupctx(fns);
 546             break;
 547         case OSSL_FUNC_DIGEST_SIZE:
 548             if (md->size != NULL)
 549                 break;
 550             md->size = OSSL_get_OP_digest_size(fns);
 551             break;
 552         case OSSL_FUNC_DIGEST_BLOCK_SIZE:
 553             if (md->dblock_size != NULL)
 554                 break;
 555             md->dblock_size = OSSL_get_OP_digest_block_size(fns);
 556             break;
 557         }
 558     }
 559     if ((fncnt != 0 && fncnt != 5)
 560         || (fncnt == 0 && md->digest == NULL)
 561         || md->size == NULL) {
 562         /*
 563          * In order to be a consistent set of functions we either need the
 564          * whole set of init/update/final etc functions or none of them.
 565          * The "digest" function can standalone. We at least need one way to
 566          * generate digests.
 567          */
 568         EVP_MD_meth_free(md);
 569         return NULL;
 570     }
 571     md->prov = prov;
 572     if (prov != NULL)
 573         ossl_provider_upref(prov);
 574
 575     return md;
 576 }
 577
 578 static int evp_md_upref(void *md)
 579 {
 580     return EVP_MD_upref(md);
 581 }
 582
 583 static void evp_md_free(void *md)
 584 {
 585     EVP_MD_meth_free(md);
 586 }
 587
 588 EVP_MD *EVP_MD_fetch(OPENSSL_CTX *ctx, const char *algorithm,
 589                      const char *properties)
 590 {
 591     return evp_generic_fetch(ctx, OSSL_OP_DIGEST, algorithm, properties,
 592                              evp_md_from_dispatch, evp_md_upref,
 593                              evp_md_free);
 594 }