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         case NID_md2:
 149             break;
 150         default:
 151             goto legacy;
 152         }
 153     }
 154
 155     if (ctx->digest != NULL && ctx->digest->ctx_size > 0) {
 156         OPENSSL_clear_free(ctx->md_data, ctx->digest->ctx_size);
 157         ctx->md_data = NULL;
 158     }
 159
 160     /* TODO(3.0): Start of non-legacy code below */
 161
 162     if (type->prov == NULL) {
 163         provmd = EVP_MD_fetch(NULL, OBJ_nid2sn(type->type), "");
 164         if (provmd == NULL) {
 165             EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_INITIALIZATION_ERROR);
 166             return 0;
 167         }
 168         type = provmd;
 169         EVP_MD_meth_free(ctx->fetched_digest);
 170         ctx->fetched_digest = provmd;
 171     }
 172
 173     ctx->digest = type;
 174     if (ctx->provctx == NULL) {
 175         ctx->provctx = ctx->digest->newctx(ossl_provider_ctx(type->prov));
 176         if (ctx->provctx == NULL) {
 177             EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_INITIALIZATION_ERROR);
 178             return 0;
 179         }
 180     }
 181
 182     if (ctx->digest->dinit == NULL) {
 183         EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_INITIALIZATION_ERROR);
 184         return 0;
 185     }
 186
 187     return ctx->digest->dinit(ctx->provctx);
 188
 189     /* TODO(3.0): Remove legacy code below */
 190  legacy:
 191
 192 #ifndef OPENSSL_NO_ENGINE
 193     if (type) {
 194         /*
 195          * Ensure an ENGINE left lying around from last time is cleared (the
 196          * previous check attempted to avoid this if the same ENGINE and
 197          * EVP_MD could be used).
 198          */
 199         ENGINE_finish(ctx->engine);
 200         if (impl != NULL) {
 201             if (!ENGINE_init(impl)) {
 202                 EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_INITIALIZATION_ERROR);
 203                 return 0;
 204             }
 205         } else {
 206             /* Ask if an ENGINE is reserved for this job */
 207             impl = tmpimpl;
 208         }
 209         if (impl != NULL) {
 210             /* There's an ENGINE for this job ... (apparently) */
 211             const EVP_MD *d = ENGINE_get_digest(impl, type->type);
 212
 213             if (d == NULL) {
 214                 EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_INITIALIZATION_ERROR);
 215                 ENGINE_finish(impl);
 216                 return 0;
 217             }
 218             /* We'll use the ENGINE's private digest definition */
 219             type = d;
 220             /*
 221              * Store the ENGINE functional reference so we know 'type' came
 222              * from an ENGINE and we need to release it when done.
 223              */
 224             ctx->engine = impl;
 225         } else
 226             ctx->engine = NULL;
 227     } else {
 228         if (!ctx->digest) {
 229             EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_NO_DIGEST_SET);
 230             return 0;
 231         }
 232         type = ctx->digest;
 233     }
 234 #endif
 235     if (ctx->digest != type) {
 236         if (ctx->digest && ctx->digest->ctx_size) {
 237             OPENSSL_clear_free(ctx->md_data, ctx->digest->ctx_size);
 238             ctx->md_data = NULL;
 239         }
 240         ctx->digest = type;
 241         if (!(ctx->flags & EVP_MD_CTX_FLAG_NO_INIT) && type->ctx_size) {
 242             ctx->update = type->update;
 243             ctx->md_data = OPENSSL_zalloc(type->ctx_size);
 244             if (ctx->md_data == NULL) {
 245                 EVPerr(EVP_F_EVP_DIGESTINIT_EX, ERR_R_MALLOC_FAILURE);
 246                 return 0;
 247             }
 248         }
 249     }
 250 #ifndef OPENSSL_NO_ENGINE
 251  skip_to_init:
 252 #endif
 253     if (ctx->pctx) {
 254         int r;
 255         r = EVP_PKEY_CTX_ctrl(ctx->pctx, -1, EVP_PKEY_OP_TYPE_SIG,
 256                               EVP_PKEY_CTRL_DIGESTINIT, 0, ctx);
 257         if (r <= 0 && (r != -2))
 258             return 0;
 259     }
 260     if (ctx->flags & EVP_MD_CTX_FLAG_NO_INIT)
 261         return 1;
 262     return ctx->digest->init(ctx);
 263 }
 264
 265 int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *data, size_t count)
 266 {
 267     if (count == 0)
 268         return 1;
 269
 270     if (ctx->digest == NULL || ctx->digest->prov == NULL)
 271         goto legacy;
 272
 273     if (ctx->digest->dupdate == NULL) {
 274         EVPerr(EVP_F_EVP_DIGESTUPDATE, EVP_R_UPDATE_ERROR);
 275         return 0;
 276     }
 277     return ctx->digest->dupdate(ctx->provctx, data, count);
 278
 279     /* TODO(3.0): Remove legacy code below */
 280  legacy:
 281     return ctx->update(ctx, data, count);
 282 }
 283
 284 /* The caller can assume that this removes any secret data from the context */
 285 int EVP_DigestFinal(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *size)
 286 {
 287     int ret;
 288     ret = EVP_DigestFinal_ex(ctx, md, size);
 289     EVP_MD_CTX_reset(ctx);
 290     return ret;
 291 }
 292
 293 /* The caller can assume that this removes any secret data from the context */
 294 int EVP_DigestFinal_ex(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *isize)
 295 {
 296     int ret;
 297     size_t size = 0;
 298     size_t mdsize = EVP_MD_size(ctx->digest);
 299
 300     if (ctx->digest == NULL || ctx->digest->prov == NULL)
 301         goto legacy;
 302
 303     if (ctx->digest->dfinal == NULL) {
 304         EVPerr(EVP_F_EVP_DIGESTFINAL_EX, EVP_R_FINAL_ERROR);
 305         return 0;
 306     }
 307
 308     ret = ctx->digest->dfinal(ctx->provctx, md, &size, mdsize);
 309
 310     if (isize != NULL) {
 311         if (size <= UINT_MAX) {
 312             *isize = (int)size;
 313         } else {
 314             EVPerr(EVP_F_EVP_DIGESTFINAL_EX, EVP_R_FINAL_ERROR);
 315             ret = 0;
 316         }
 317     }
 318
 319     EVP_MD_CTX_reset(ctx);
 320
 321     return ret;
 322
 323     /* TODO(3.0): Remove legacy code below */
 324  legacy:
 325     OPENSSL_assert(mdsize <= EVP_MAX_MD_SIZE);
 326     ret = ctx->digest->final(ctx, md);
 327     if (isize != NULL)
 328         *isize = mdsize;
 329     if (ctx->digest->cleanup) {
 330         ctx->digest->cleanup(ctx);
 331         EVP_MD_CTX_set_flags(ctx, EVP_MD_CTX_FLAG_CLEANED);
 332     }
 333     OPENSSL_cleanse(ctx->md_data, ctx->digest->ctx_size);
 334     return ret;
 335 }
 336
 337 int EVP_DigestFinalXOF(EVP_MD_CTX *ctx, unsigned char *md, size_t size)
 338 {
 339     int ret = 0;
 340
 341     if (ctx->digest->flags & EVP_MD_FLAG_XOF
 342         && size <= INT_MAX
 343         && ctx->digest->md_ctrl(ctx, EVP_MD_CTRL_XOF_LEN, (int)size, NULL)) {
 344         ret = ctx->digest->final(ctx, md);
 345
 346         if (ctx->digest->cleanup != NULL) {
 347             ctx->digest->cleanup(ctx);
 348             EVP_MD_CTX_set_flags(ctx, EVP_MD_CTX_FLAG_CLEANED);
 349         }
 350         OPENSSL_cleanse(ctx->md_data, ctx->digest->ctx_size);
 351     } else {
 352         EVPerr(EVP_F_EVP_DIGESTFINALXOF, EVP_R_NOT_XOF_OR_INVALID_LENGTH);
 353     }
 354
 355     return ret;
 356 }
 357
 358 int EVP_MD_CTX_copy(EVP_MD_CTX *out, const EVP_MD_CTX *in)
 359 {
 360     EVP_MD_CTX_reset(out);
 361     return EVP_MD_CTX_copy_ex(out, in);
 362 }
 363
 364 int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in)
 365 {
 366     unsigned char *tmp_buf;
 367
 368     if (in == NULL || in->digest == NULL) {
 369         EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, EVP_R_INPUT_NOT_INITIALIZED);
 370         return 0;
 371     }
 372
 373     if (in->digest->prov == NULL)
 374         goto legacy;
 375
 376     if (in->digest->dupctx == NULL) {
 377         EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, EVP_R_NOT_ABLE_TO_COPY_CTX);
 378         return 0;
 379     }
 380
 381     EVP_MD_CTX_reset(out);
 382     if (out->fetched_digest != NULL)
 383         EVP_MD_meth_free(out->fetched_digest);
 384     *out = *in;
 385     /* NULL out pointers in case of error */
 386     out->pctx = NULL;
 387     out->provctx = NULL;
 388
 389     if (in->fetched_digest != NULL)
 390         EVP_MD_upref(in->fetched_digest);
 391
 392     out->provctx = in->digest->dupctx(in->provctx);
 393     if (out->provctx == NULL) {
 394         EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, EVP_R_NOT_ABLE_TO_COPY_CTX);
 395         return 0;
 396     }
 397
 398     /* copied EVP_MD_CTX should free the copied EVP_PKEY_CTX */
 399     EVP_MD_CTX_clear_flags(out, EVP_MD_CTX_FLAG_KEEP_PKEY_CTX);
 400     if (in->pctx != NULL) {
 401         out->pctx = EVP_PKEY_CTX_dup(in->pctx);
 402         if (out->pctx == NULL) {
 403             EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, EVP_R_NOT_ABLE_TO_COPY_CTX);
 404             EVP_MD_CTX_reset(out);
 405             return 0;
 406         }
 407     }
 408
 409     return 1;
 410
 411     /* TODO(3.0): Remove legacy code below */
 412  legacy:
 413 #ifndef OPENSSL_NO_ENGINE
 414     /* Make sure it's safe to copy a digest context using an ENGINE */
 415     if (in->engine && !ENGINE_init(in->engine)) {
 416         EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, ERR_R_ENGINE_LIB);
 417         return 0;
 418     }
 419 #endif
 420
 421     if (out->digest == in->digest) {
 422         tmp_buf = out->md_data;
 423         EVP_MD_CTX_set_flags(out, EVP_MD_CTX_FLAG_REUSE);
 424     } else
 425         tmp_buf = NULL;
 426     EVP_MD_CTX_reset(out);
 427     memcpy(out, in, sizeof(*out));
 428
 429     /* copied EVP_MD_CTX should free the copied EVP_PKEY_CTX */
 430     EVP_MD_CTX_clear_flags(out, EVP_MD_CTX_FLAG_KEEP_PKEY_CTX);
 431
 432     /* Null these variables, since they are getting fixed up
 433      * properly below.  Anything else may cause a memleak and/or
 434      * double free if any of the memory allocations below fail
 435      */
 436     out->md_data = NULL;
 437     out->pctx = NULL;
 438
 439     if (in->md_data && out->digest->ctx_size) {
 440         if (tmp_buf)
 441             out->md_data = tmp_buf;
 442         else {
 443             out->md_data = OPENSSL_malloc(out->digest->ctx_size);
 444             if (out->md_data == NULL) {
 445                 EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, ERR_R_MALLOC_FAILURE);
 446                 return 0;
 447             }
 448         }
 449         memcpy(out->md_data, in->md_data, out->digest->ctx_size);
 450     }
 451
 452     out->update = in->update;
 453
 454     if (in->pctx) {
 455         out->pctx = EVP_PKEY_CTX_dup(in->pctx);
 456         if (!out->pctx) {
 457             EVP_MD_CTX_reset(out);
 458             return 0;
 459         }
 460     }
 461
 462     if (out->digest->copy)
 463         return out->digest->copy(out, in);
 464
 465     return 1;
 466 }
 467
 468 int EVP_Digest(const void *data, size_t count,
 469                unsigned char *md, unsigned int *size, const EVP_MD *type,
 470                ENGINE *impl)
 471 {
 472     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 473     int ret;
 474
 475     if (ctx == NULL)
 476         return 0;
 477     EVP_MD_CTX_set_flags(ctx, EVP_MD_CTX_FLAG_ONESHOT);
 478     ret = EVP_DigestInit_ex(ctx, type, impl)
 479         && EVP_DigestUpdate(ctx, data, count)
 480         && EVP_DigestFinal_ex(ctx, md, size);
 481     EVP_MD_CTX_free(ctx);
 482
 483     return ret;
 484 }
 485
 486 int EVP_MD_CTX_ctrl(EVP_MD_CTX *ctx, int cmd, int p1, void *p2)
 487 {
 488     if (ctx->digest && ctx->digest->md_ctrl) {
 489         int ret = ctx->digest->md_ctrl(ctx, cmd, p1, p2);
 490         if (ret <= 0)
 491             return 0;
 492         return 1;
 493     }
 494     return 0;
 495 }
 496
 497 static void *evp_md_from_dispatch(int mdtype, const OSSL_DISPATCH *fns,
 498                                     OSSL_PROVIDER *prov)
 499 {
 500     EVP_MD *md = NULL;
 501     int fncnt = 0;
 502
 503     if ((md = EVP_MD_meth_new(mdtype, NID_undef)) == NULL)
 504         return NULL;
 505
 506     for (; fns->function_id != 0; fns++) {
 507         switch (fns->function_id) {
 508         case OSSL_FUNC_DIGEST_NEWCTX:
 509             if (md->newctx != NULL)
 510                 break;
 511             md->newctx = OSSL_get_OP_digest_newctx(fns);
 512             fncnt++;
 513             break;
 514         case OSSL_FUNC_DIGEST_INIT:
 515             if (md->dinit != NULL)
 516                 break;
 517             md->dinit = OSSL_get_OP_digest_init(fns);
 518             fncnt++;
 519             break;
 520         case OSSL_FUNC_DIGEST_UPDATE:
 521             if (md->dupdate != NULL)
 522                 break;
 523             md->dupdate = OSSL_get_OP_digest_update(fns);
 524             fncnt++;
 525             break;
 526         case OSSL_FUNC_DIGEST_FINAL:
 527             if (md->dfinal != NULL)
 528                 break;
 529             md->dfinal = OSSL_get_OP_digest_final(fns);
 530             fncnt++;
 531             break;
 532         case OSSL_FUNC_DIGEST_DIGEST:
 533             if (md->digest != NULL)
 534                 break;
 535             md->digest = OSSL_get_OP_digest_digest(fns);
 536             /* We don't increment fnct for this as it is stand alone */
 537             break;
 538         case OSSL_FUNC_DIGEST_FREECTX:
 539             if (md->freectx != NULL)
 540                 break;
 541             md->freectx = OSSL_get_OP_digest_freectx(fns);
 542             fncnt++;
 543             break;
 544         case OSSL_FUNC_DIGEST_DUPCTX:
 545             if (md->dupctx != NULL)
 546                 break;
 547             md->dupctx = OSSL_get_OP_digest_dupctx(fns);
 548             break;
 549         case OSSL_FUNC_DIGEST_SIZE:
 550             if (md->size != NULL)
 551                 break;
 552             md->size = OSSL_get_OP_digest_size(fns);
 553             break;
 554         case OSSL_FUNC_DIGEST_BLOCK_SIZE:
 555             if (md->dblock_size != NULL)
 556                 break;
 557             md->dblock_size = OSSL_get_OP_digest_block_size(fns);
 558             break;
 559         }
 560     }
 561     if ((fncnt != 0 && fncnt != 5)
 562         || (fncnt == 0 && md->digest == NULL)
 563         || md->size == NULL) {
 564         /*
 565          * In order to be a consistent set of functions we either need the
 566          * whole set of init/update/final etc functions or none of them.
 567          * The "digest" function can standalone. We at least need one way to
 568          * generate digests.
 569          */
 570         EVP_MD_meth_free(md);
 571         return NULL;
 572     }
 573     md->prov = prov;
 574     if (prov != NULL)
 575         ossl_provider_upref(prov);
 576
 577     return md;
 578 }
 579
 580 static int evp_md_upref(void *md)
 581 {
 582     return EVP_MD_upref(md);
 583 }
 584
 585 static void evp_md_free(void *md)
 586 {
 587     EVP_MD_meth_free(md);
 588 }
 589
 590 static int evp_md_nid(void *vmd)
 591 {
 592     EVP_MD *md = vmd;
 593
 594     return md->type;
 595 }
 596
 597 EVP_MD *EVP_MD_fetch(OPENSSL_CTX *ctx, const char *algorithm,
 598                      const char *properties)
 599 {
 600     return evp_generic_fetch(ctx, OSSL_OP_DIGEST, algorithm, properties,
 601                              evp_md_from_dispatch, evp_md_upref,
 602                              evp_md_free, evp_md_nid);
 603 }