lib/libcrypto/evp/bio_md.c

   1 /* $OpenBSD: bio_md.c,v 1.15 2018/05/02 15:51:41 tb Exp $ */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include <stdio.h>
  60 #include <errno.h>
  61
  62 #include <openssl/buffer.h>
  63 #include <openssl/evp.h>
  64
  65 /* BIO_put and BIO_get both add to the digest,
  66  * BIO_gets returns the digest */
  67
  68 static int md_write(BIO *h, char const *buf, int num);
  69 static int md_read(BIO *h, char *buf, int size);
  70 /*static int md_puts(BIO *h, const char *str); */
  71 static int md_gets(BIO *h, char *str, int size);
  72 static long md_ctrl(BIO *h, int cmd, long arg1, void *arg2);
  73 static int md_new(BIO *h);
  74 static int md_free(BIO *data);
  75 static long md_callback_ctrl(BIO *h, int cmd, bio_info_cb *fp);
  76
  77 static const BIO_METHOD methods_md = {
  78         .type = BIO_TYPE_MD,
  79         .name = "message digest",
  80         .bwrite = md_write,
  81         .bread = md_read,
  82         .bgets = md_gets,
  83         .ctrl = md_ctrl,
  84         .create = md_new,
  85         .destroy = md_free,
  86         .callback_ctrl = md_callback_ctrl
  87 };
  88
  89 const BIO_METHOD *
  90 BIO_f_md(void)
  91 {
  92         return (&methods_md);
  93 }
  94
  95 static int
  96 md_new(BIO *bi)
  97 {
  98         EVP_MD_CTX *ctx;
  99
 100         ctx = EVP_MD_CTX_create();
 101         if (ctx == NULL)
 102                 return (0);
 103
 104         bi->init = 0;
 105         bi->ptr = (char *)ctx;
 106         bi->flags = 0;
 107         return (1);
 108 }
 109
 110 static int
 111 md_free(BIO *a)
 112 {
 113         if (a == NULL)
 114                 return (0);
 115         EVP_MD_CTX_destroy(a->ptr);
 116         a->ptr = NULL;
 117         a->init = 0;
 118         a->flags = 0;
 119         return (1);
 120 }
 121
 122 static int
 123 md_read(BIO *b, char *out, int outl)
 124 {
 125         int ret = 0;
 126         EVP_MD_CTX *ctx;
 127
 128         if (out == NULL)
 129                 return (0);
 130         ctx = b->ptr;
 131
 132         if ((ctx == NULL) || (b->next_bio == NULL))
 133                 return (0);
 134
 135         ret = BIO_read(b->next_bio, out, outl);
 136         if (b->init) {
 137                 if (ret > 0) {
 138                         if (EVP_DigestUpdate(ctx, (unsigned char *)out,
 139                             (unsigned int)ret) <= 0)
 140                                 return (-1);
 141                 }
 142         }
 143         BIO_clear_retry_flags(b);
 144         BIO_copy_next_retry(b);
 145         return (ret);
 146 }
 147
 148 static int
 149 md_write(BIO *b, const char *in, int inl)
 150 {
 151         int ret = 0;
 152         EVP_MD_CTX *ctx;
 153
 154         if ((in == NULL) || (inl <= 0))
 155                 return (0);
 156         ctx = b->ptr;
 157
 158         if ((ctx != NULL) && (b->next_bio != NULL))
 159                 ret = BIO_write(b->next_bio, in, inl);
 160         if (b->init) {
 161                 if (ret > 0) {
 162                         if (!EVP_DigestUpdate(ctx, (const unsigned char *)in,
 163                             (unsigned int)ret)) {
 164                                 BIO_clear_retry_flags(b);
 165                                 return 0;
 166                         }
 167                 }
 168         }
 169         if (b->next_bio != NULL) {
 170                 BIO_clear_retry_flags(b);
 171                 BIO_copy_next_retry(b);
 172         }
 173         return (ret);
 174 }
 175
 176 static long
 177 md_ctrl(BIO *b, int cmd, long num, void *ptr)
 178 {
 179         EVP_MD_CTX *ctx, *dctx, **pctx;
 180         const EVP_MD **ppmd;
 181         EVP_MD *md;
 182         long ret = 1;
 183         BIO *dbio;
 184
 185         ctx = b->ptr;
 186
 187         switch (cmd) {
 188         case BIO_CTRL_RESET:
 189                 if (b->init)
 190                         ret = EVP_DigestInit_ex(ctx, ctx->digest, NULL);
 191                 else
 192                         ret = 0;
 193                 if (ret > 0)
 194                         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 195                 break;
 196         case BIO_C_GET_MD:
 197                 if (b->init) {
 198                         ppmd = ptr;
 199                         *ppmd = ctx->digest;
 200                 } else
 201                         ret = 0;
 202                 break;
 203         case BIO_C_GET_MD_CTX:
 204                 pctx = ptr;
 205                 *pctx = ctx;
 206                 b->init = 1;
 207                 break;
 208         case BIO_C_SET_MD_CTX:
 209                 if (b->init)
 210                         b->ptr = ptr;
 211                 else
 212                         ret = 0;
 213                 break;
 214         case BIO_C_DO_STATE_MACHINE:
 215                 BIO_clear_retry_flags(b);
 216                 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 217                 BIO_copy_next_retry(b);
 218                 break;
 219
 220         case BIO_C_SET_MD:
 221                 md = ptr;
 222                 ret = EVP_DigestInit_ex(ctx, md, NULL);
 223                 if (ret > 0)
 224                         b->init = 1;
 225                 break;
 226         case BIO_CTRL_DUP:
 227                 dbio = ptr;
 228                 dctx = dbio->ptr;
 229                 if (!EVP_MD_CTX_copy_ex(dctx, ctx))
 230                         return 0;
 231                 b->init = 1;
 232                 break;
 233         default:
 234                 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 235                 break;
 236         }
 237         return (ret);
 238 }
 239
 240 static long
 241 md_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
 242 {
 243         long ret = 1;
 244
 245         if (b->next_bio == NULL)
 246                 return (0);
 247         switch (cmd) {
 248         default:
 249                 ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
 250                 break;
 251         }
 252         return (ret);
 253 }
 254
 255 static int
 256 md_gets(BIO *bp, char *buf, int size)
 257 {
 258         EVP_MD_CTX *ctx;
 259         unsigned int ret;
 260
 261         ctx = bp->ptr;
 262         if (size < ctx->digest->md_size)
 263                 return (0);
 264         if (EVP_DigestFinal_ex(ctx, (unsigned char *)buf, &ret) <= 0)
 265                 return -1;
 266
 267         return ((int)ret);
 268 }
 269
 270 /*
 271 static int md_puts(bp,str)
 272 BIO *bp;
 273 char *str;
 274         {
 275         return(-1);
 276         }
 277 */