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     OPENSSL_cleanse(ctx, 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 &&
  72         (type == NULL || (type->type == ctx->digest->type)))
  73         goto skip_to_init;
  74     if (type) {
  75         /*
  76          * Ensure an ENGINE left lying around from last time is cleared (the
  77          * previous check attempted to avoid this if the same ENGINE and
  78          * EVP_MD could be used).
  79          */
  80         ENGINE_finish(ctx->engine);
  81         if (impl != NULL) {
  82             if (!ENGINE_init(impl)) {
  83                 EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_INITIALIZATION_ERROR);
  84                 return 0;
  85             }
  86         } else {
  87             /* Ask if an ENGINE is reserved for this job */
  88             impl = ENGINE_get_digest_engine(type->type);
  89         }
  90         if (impl != NULL) {
  91             /* There's an ENGINE for this job ... (apparently) */
  92             const EVP_MD *d = ENGINE_get_digest(impl, type->type);
  93
  94             if (d == NULL) {
  95                 EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_INITIALIZATION_ERROR);
  96                 ENGINE_finish(impl);
  97                 return 0;
  98             }
  99             /* We'll use the ENGINE's private digest definition */
 100             type = d;
 101             /*
 102              * Store the ENGINE functional reference so we know 'type' came
 103              * from an ENGINE and we need to release it when done.
 104              */
 105             ctx->engine = impl;
 106         } else
 107             ctx->engine = NULL;
 108     } else {
 109         if (!ctx->digest) {
 110             EVPerr(EVP_F_EVP_DIGESTINIT_EX, EVP_R_NO_DIGEST_SET);
 111             return 0;
 112         }
 113         type = ctx->digest;
 114     }
 115 #endif
 116     if (ctx->digest != type) {
 117         if (ctx->digest && ctx->digest->ctx_size) {
 118             OPENSSL_clear_free(ctx->md_data, ctx->digest->ctx_size);
 119             ctx->md_data = NULL;
 120         }
 121         ctx->digest = type;
 122         if (!(ctx->flags & EVP_MD_CTX_FLAG_NO_INIT) && type->ctx_size) {
 123             ctx->update = type->update;
 124             ctx->md_data = OPENSSL_zalloc(type->ctx_size);
 125             if (ctx->md_data == NULL) {
 126                 EVPerr(EVP_F_EVP_DIGESTINIT_EX, ERR_R_MALLOC_FAILURE);
 127                 return 0;
 128             }
 129         }
 130     }
 131 #ifndef OPENSSL_NO_ENGINE
 132  skip_to_init:
 133 #endif
 134     if (ctx->pctx) {
 135         int r;
 136         r = EVP_PKEY_CTX_ctrl(ctx->pctx, -1, EVP_PKEY_OP_TYPE_SIG,
 137                               EVP_PKEY_CTRL_DIGESTINIT, 0, ctx);
 138         if (r <= 0 && (r != -2))
 139             return 0;
 140     }
 141     if (ctx->flags & EVP_MD_CTX_FLAG_NO_INIT)
 142         return 1;
 143     return ctx->digest->init(ctx);
 144 }
 145
 146 int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *data, size_t count)
 147 {
 148     return ctx->update(ctx, data, count);
 149 }
 150
 151 /* The caller can assume that this removes any secret data from the context */
 152 int EVP_DigestFinal(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *size)
 153 {
 154     int ret;
 155     ret = EVP_DigestFinal_ex(ctx, md, size);
 156     EVP_MD_CTX_reset(ctx);
 157     return ret;
 158 }
 159
 160 /* The caller can assume that this removes any secret data from the context */
 161 int EVP_DigestFinal_ex(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *size)
 162 {
 163     int ret;
 164
 165     OPENSSL_assert(ctx->digest->md_size <= EVP_MAX_MD_SIZE);
 166     ret = ctx->digest->final(ctx, md);
 167     if (size != NULL)
 168         *size = ctx->digest->md_size;
 169     if (ctx->digest->cleanup) {
 170         ctx->digest->cleanup(ctx);
 171         EVP_MD_CTX_set_flags(ctx, EVP_MD_CTX_FLAG_CLEANED);
 172     }
 173     OPENSSL_cleanse(ctx->md_data, ctx->digest->ctx_size);
 174     return ret;
 175 }
 176
 177 int EVP_DigestFinalXOF(EVP_MD_CTX *ctx, unsigned char *md, size_t size)
 178 {
 179     int ret = 0;
 180
 181     if (ctx->digest->flags & EVP_MD_FLAG_XOF
 182         && size <= INT_MAX
 183         && ctx->digest->md_ctrl(ctx, EVP_MD_CTRL_XOF_LEN, (int)size, NULL)) {
 184         ret = ctx->digest->final(ctx, md);
 185
 186         if (ctx->digest->cleanup != NULL) {
 187             ctx->digest->cleanup(ctx);
 188             EVP_MD_CTX_set_flags(ctx, EVP_MD_CTX_FLAG_CLEANED);
 189         }
 190         OPENSSL_cleanse(ctx->md_data, ctx->digest->ctx_size);
 191     } else {
 192         EVPerr(EVP_F_EVP_DIGESTFINALXOF, EVP_R_NOT_XOF_OR_INVALID_LENGTH);
 193     }
 194
 195     return ret;
 196 }
 197
 198 int EVP_MD_CTX_copy(EVP_MD_CTX *out, const EVP_MD_CTX *in)
 199 {
 200     EVP_MD_CTX_reset(out);
 201     return EVP_MD_CTX_copy_ex(out, in);
 202 }
 203
 204 int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in)
 205 {
 206     unsigned char *tmp_buf;
 207     if ((in == NULL) || (in->digest == NULL)) {
 208         EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, EVP_R_INPUT_NOT_INITIALIZED);
 209         return 0;
 210     }
 211 #ifndef OPENSSL_NO_ENGINE
 212     /* Make sure it's safe to copy a digest context using an ENGINE */
 213     if (in->engine && !ENGINE_init(in->engine)) {
 214         EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, ERR_R_ENGINE_LIB);
 215         return 0;
 216     }
 217 #endif
 218
 219     if (out->digest == in->digest) {
 220         tmp_buf = out->md_data;
 221         EVP_MD_CTX_set_flags(out, EVP_MD_CTX_FLAG_REUSE);
 222     } else
 223         tmp_buf = NULL;
 224     EVP_MD_CTX_reset(out);
 225     memcpy(out, in, sizeof(*out));
 226
 227     /* Null these variables, since they are getting fixed up
 228      * properly below.  Anything else may cause a memleak and/or
 229      * double free if any of the memory allocations below fail
 230      */
 231     out->md_data = NULL;
 232     out->pctx = NULL;
 233
 234     if (in->md_data && out->digest->ctx_size) {
 235         if (tmp_buf)
 236             out->md_data = tmp_buf;
 237         else {
 238             out->md_data = OPENSSL_malloc(out->digest->ctx_size);
 239             if (out->md_data == NULL) {
 240                 EVPerr(EVP_F_EVP_MD_CTX_COPY_EX, ERR_R_MALLOC_FAILURE);
 241                 return 0;
 242             }
 243         }
 244         memcpy(out->md_data, in->md_data, out->digest->ctx_size);
 245     }
 246
 247     out->update = in->update;
 248
 249     if (in->pctx) {
 250         out->pctx = EVP_PKEY_CTX_dup(in->pctx);
 251         if (!out->pctx) {
 252             EVP_MD_CTX_reset(out);
 253             return 0;
 254         }
 255     }
 256
 257     if (out->digest->copy)
 258         return out->digest->copy(out, in);
 259
 260     return 1;
 261 }
 262
 263 int EVP_Digest(const void *data, size_t count,
 264                unsigned char *md, unsigned int *size, const EVP_MD *type,
 265                ENGINE *impl)
 266 {
 267     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 268     int ret;
 269
 270     if (ctx == NULL)
 271         return 0;
 272     EVP_MD_CTX_set_flags(ctx, EVP_MD_CTX_FLAG_ONESHOT);
 273     ret = EVP_DigestInit_ex(ctx, type, impl)
 274         && EVP_DigestUpdate(ctx, data, count)
 275         && EVP_DigestFinal_ex(ctx, md, size);
 276     EVP_MD_CTX_free(ctx);
 277
 278     return ret;
 279 }
 280
 281 int EVP_MD_CTX_ctrl(EVP_MD_CTX *ctx, int cmd, int p1, void *p2)
 282 {
 283     if (ctx->digest && ctx->digest->md_ctrl) {
 284         int ret = ctx->digest->md_ctrl(ctx, cmd, p1, p2);
 285         if (ret <= 0)
 286             return 0;
 287         return 1;
 288     }
 289     return 0;
 290 }