crypto/evp/digest.c

   1 /*
   2  * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (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 "evp_locl.h"
  17
  18 /* This call frees resources associated with the context */
  19 int EVP_MD_CTX_reset(EVP_MD_CTX *ctx)
  20 {
  21     if (ctx == NULL)
  22         return 1;
  23
  24     /*
  25      * Don't assume ctx->md_data was cleaned in EVP_Digest_Final, because
  26      * sometimes only copies of the context are ever finalised.
  27      */
  28     if (ctx->digest && ctx->digest->cleanup
  29         && !EVP_MD_CTX_test_flags(ctx, EVP_MD_CTX_FLAG_CLEANED))
  30         ctx->digest->cleanup(ctx);
  31     if (ctx->digest && ctx->digest->ctx_size && ctx->md_data
  32         && !EVP_MD_CTX_test_flags(ctx, EVP_MD_CTX_FLAG_REUSE)) {
  33         OPENSSL_clear_free(ctx->md_data, ctx->digest->ctx_size);
  34     }
  35     EVP_PKEY_CTX_free(ctx->pctx);
  36 #ifndef OPENSSL_NO_ENGINE
  37     ENGINE_finish(ctx->engine);
  38 #endif
  39     memset(ctx, 0, sizeof(*ctx));
  40
  41     return 1;
  42 }
  43
  44 EVP_MD_CTX *EVP_MD_CTX_new(void)
  45 {
  46     return OPENSSL_zalloc(sizeof(EVP_MD_CTX));
  47 }
  48
  49 void EVP_MD_CTX_free(EVP_MD_CTX *ctx)
  50 {
  51     EVP_MD_CTX_reset(ctx);
  52     OPENSSL_free(ctx);
  53 }
  54
  55 int EVP_DigestInit(EVP_MD_CTX *ctx, const EVP_MD *type)
  56 {
  57     EVP_MD_CTX_reset(ctx);
  58     return EVP_DigestInit_ex(ctx, type, NULL);
  59 }
  60
  61 int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl)
  62 {
  63     EVP_MD_CTX_clear_flags(ctx, EVP_MD_CTX_FLAG_CLEANED);
  64 #ifndef OPENSSL_NO_ENGINE
  65     /*
  66      * Whether it's nice or not, "Inits" can be used on "Final"'d contexts so
  67      * this context may already have an ENGINE! Try to avoid releasing the
  68      * previous handle, re-querying for an ENGINE, and having a
  69      * reinitialisation, when it may all be unnecessary.
  70      */
  71     if (ctx->engine && ctx->digest && (!type ||
  72                                        (type
  73                                         && (type->type ==
  74                                             ctx->digest->type))))
  75         goto skip_to_init;
  76     if (type) {
  77         /*
  78          * Ensure an ENGINE left lying around from last time is cleared (the
  79          * previous check attempted to avoid this if the same ENGINE and
  80          * EVP_MD could be used).
  81          */
  82         ENGINE_finish(ctx->engine);
  83         if (impl != NULL) {
  84             if (!ENGINE_init(impl)) {
  85                 EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_INITIALIZATION_ERROR);
  86                 return 0;
  87             }
  88         } else {
  89             /* Ask if an ENGINE is reserved for this job */
  90             impl = ENGINE_get_digest_engine(type->type);
  91         }
  92         if (impl != NULL) {
  93             /* There's an ENGINE for this job ... (apparently) */
  94             const EVP_MD *d = ENGINE_get_digest(impl, type->type);
  95
  96             if (d == NULL) {
  97                 EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_INITIALIZATION_ERROR);
  98                 ENGINE_finish(impl);
  99                 return 0;
 100             }
 101             /* We'll use the ENGINE's private digest definition */
 102             type = d;
 103             /*
 104              * Store the ENGINE functional reference so we know 'type' came
 105              * from an ENGINE and we need to release it when done.
 106              */
 107             ctx->engine = impl;
 108         } else
 109             ctx->engine = NULL;
 110     } else {
 111         if (!ctx->digest) {
 112             EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_NO_DIGEST_SET);
 113             return 0;
 114         }
 115         type = ctx->digest;
 116     }
 117 #endif
 118     if (ctx->digest != type) {
 119         if (ctx->digest && ctx->digest->ctx_size) {
 120             OPENSSL_free(ctx->md_data);
 121             ctx->md_data = NULL;
 122         }
 123         ctx->digest = type;
 124         if (!(ctx->flags & EVP_MD_CTX_FLAG_NO_INIT) && type->ctx_size) {
 125             ctx->update = type->update;
 126             ctx->md_data = OPENSSL_zalloc(type->ctx_size);
 127             if (ctx->md_data == NULL) {
 128                 EVPerr(EVP_F_EVP_DIGESTINIT_EX, ERR_R_MALLOC_FAILURE);
 129                 return 0;
 130             }
 131         }
 132     }
 133 #ifndef OPENSSL_NO_ENGINE
 134  skip_to_init:
 135 #endif
 136     if (ctx->pctx) {
 137         int r;
 138         r = EVP_PKEY_CTX_ctrl(ctx->pctx, -1, EVP_PKEY_OP_TYPE_SIG,
 139                               EVP_PKEY_CTRL_DIGESTINIT, 0, ctx);
 140         if (r <= 0 && (r != -2))
 141             return 0;
 142     }
 143     if (ctx->flags & EVP_MD_CTX_FLAG_NO_INIT)
 144         return 1;
 145     return ctx->digest->init(ctx);
 146 }
 147
 148 int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *data, size_t count)
 149 {
 150     return ctx->update(ctx, data, count);
 151 }
 152
 153 /* The caller can assume that this removes any secret data from the context */
 154 int EVP_DigestFinal(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *size)
 155 {
 156     int ret;
 157     ret = EVP_DigestFinal_ex(ctx, md, size);
 158     EVP_MD_CTX_reset(ctx);
 159     return ret;
 160 }
 161
 162 /* The caller can assume that this removes any secret data from the context */
 163 int EVP_DigestFinal_ex(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *size)
 164 {
 165     int ret;
 166
 167     OPENSSL_assert(ctx->digest->md_size <= EVP_MAX_MD_SIZE);
 168     ret = ctx->digest->final(ctx, md);
 169     if (size != NULL)
 170         *size = ctx->digest->md_size;
 171     if (ctx->digest->cleanup) {
 172         ctx->digest->cleanup(ctx);
 173         EVP_MD_CTX_set_flags(ctx, EVP_MD_CTX_FLAG_CLEANED);
 174     }
 175     memset(ctx->md_data, 0, ctx->digest->ctx_size);
 176     return ret;
 177 }
 178
 179 int EVP_MD_CTX_copy(EVP_MD_CTX *out, const EVP_MD_CTX *in)
 180 {
 181     EVP_MD_CTX_reset(out);
 182     return EVP_MD_CTX_copy_ex(out, in);
 183 }
 184
 185 int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in)
 186 {
 187     unsigned char *tmp_buf;
 188     if ((in == NULL) || (in->digest == NULL)) {
 189         EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, EVP_R_INPUT_NOT_INITIALIZED);
 190         return 0;
 191     }
 192 #ifndef OPENSSL_NO_ENGINE
 193     /* Make sure it's safe to copy a digest context using an ENGINE */
 194     if (in->engine && !ENGINE_init(in->engine)) {
 195         EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, ERR_R_ENGINE_LIB);
 196         return 0;
 197     }
 198 #endif
 199
 200     if (out->digest == in->digest) {
 201         tmp_buf = out->md_data;
 202         EVP_MD_CTX_set_flags(out, EVP_MD_CTX_FLAG_REUSE);
 203     } else
 204         tmp_buf = NULL;
 205     EVP_MD_CTX_reset(out);
 206     memcpy(out, in, sizeof(*out));
 207
 208     /* Null these variables, since they are getting fixed up
 209      * properly below.  Anything else may cause a memleak and/or
 210      * double free if any of the memory allocations below fail
 211      */
 212     out->md_data = NULL;
 213     out->pctx = NULL;
 214
 215     if (in->md_data && out->digest->ctx_size) {
 216         if (tmp_buf)
 217             out->md_data = tmp_buf;
 218         else {
 219             out->md_data = OPENSSL_malloc(out->digest->ctx_size);
 220             if (out->md_data == NULL) {
 221                 EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, ERR_R_MALLOC_FAILURE);
 222                 return 0;
 223             }
 224         }
 225         memcpy(out->md_data, in->md_data, out->digest->ctx_size);
 226     }
 227
 228     out->update = in->update;
 229
 230     if (in->pctx) {
 231         out->pctx = EVP_PKEY_CTX_dup(in->pctx);
 232         if (!out->pctx) {
 233             EVP_MD_CTX_reset(out);
 234             return 0;
 235         }
 236     }
 237
 238     if (out->digest->copy)
 239         return out->digest->copy(out, in);
 240
 241     return 1;
 242 }
 243
 244 int EVP_Digest(const void *data, size_t count,
 245                unsigned char *md, unsigned int *size, const EVP_MD *type,
 246                ENGINE *impl)
 247 {
 248     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 249     int ret;
 250
 251     if (ctx == NULL)
 252         return 0;
 253     EVP_MD_CTX_set_flags(ctx, EVP_MD_CTX_FLAG_ONESHOT);
 254     ret = EVP_DigestInit_ex(ctx, type, impl)
 255         && EVP_DigestUpdate(ctx, data, count)
 256         && EVP_DigestFinal_ex(ctx, md, size);
 257     EVP_MD_CTX_free(ctx);
 258
 259     return ret;
 260 }
 261
 262 int EVP_MD_CTX_ctrl(EVP_MD_CTX *ctx, int cmd, int p1, void *p2)
 263 {
 264     if (ctx->digest && ctx->digest->md_ctrl) {
 265         int ret = ctx->digest->md_ctrl(ctx, cmd, p1, p2);
 266         if (ret <= 0)
 267             return 0;
 268         return 1;
 269     }
 270     return 0;
 271 }