crypto/evp/bio_md.c

   1 /*
   2  * Copyright 1995-2016 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 <errno.h>
  12 #include <openssl/buffer.h>
  13 #include <openssl/evp.h>
  14 #include "internal/bio.h"
  15
  16 /*
  17  * BIO_put and BIO_get both add to the digest, BIO_gets returns the digest
  18  */
  19
  20 static int md_write(BIO *h, char const *buf, int num);
  21 static int md_read(BIO *h, char *buf, int size);
  22 static int md_gets(BIO *h, char *str, int size);
  23 static long md_ctrl(BIO *h, int cmd, long arg1, void *arg2);
  24 static int md_new(BIO *h);
  25 static int md_free(BIO *data);
  26 static long md_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
  27
  28 static const BIO_METHOD methods_md = {
  29     BIO_TYPE_MD,
  30     "message digest",
  31     /* TODO: Convert to new style write function */
  32     bwrite_conv,
  33     md_write,
  34     /* TODO: Convert to new style read function */
  35     bread_conv,
  36     md_read,
  37     NULL,                       /* md_puts, */
  38     md_gets,
  39     md_ctrl,
  40     md_new,
  41     md_free,
  42     md_callback_ctrl,
  43 };
  44
  45 const BIO_METHOD *BIO_f_md(void)
  46 {
  47     return &methods_md;
  48 }
  49
  50 static int md_new(BIO *bi)
  51 {
  52     EVP_MD_CTX *ctx;
  53
  54     ctx = EVP_MD_CTX_new();
  55     if (ctx == NULL)
  56         return 0;
  57
  58     BIO_set_init(bi, 1);
  59     BIO_set_data(bi, ctx);
  60
  61     return 1;
  62 }
  63
  64 static int md_free(BIO *a)
  65 {
  66     if (a == NULL)
  67         return 0;
  68     EVP_MD_CTX_free(BIO_get_data(a));
  69     BIO_set_data(a, NULL);
  70     BIO_set_init(a, 0);
  71
  72     return 1;
  73 }
  74
  75 static int md_read(BIO *b, char *out, int outl)
  76 {
  77     int ret = 0;
  78     EVP_MD_CTX *ctx;
  79     BIO *next;
  80
  81     if (out == NULL)
  82         return 0;
  83
  84     ctx = BIO_get_data(b);
  85     next = BIO_next(b);
  86
  87     if ((ctx == NULL) || (next == NULL))
  88         return 0;
  89
  90     ret = BIO_read(next, out, outl);
  91     if (BIO_get_init(b)) {
  92         if (ret > 0) {
  93             if (EVP_DigestUpdate(ctx, (unsigned char *)out,
  94                                  (unsigned int)ret) <= 0)
  95                 return -1;
  96         }
  97     }
  98     BIO_clear_retry_flags(b);
  99     BIO_copy_next_retry(b);
 100     return ret;
 101 }
 102
 103 static int md_write(BIO *b, const char *in, int inl)
 104 {
 105     int ret = 0;
 106     EVP_MD_CTX *ctx;
 107     BIO *next;
 108
 109     if ((in == NULL) || (inl <= 0))
 110         return 0;
 111
 112     ctx = BIO_get_data(b);
 113     next = BIO_next(b);
 114     if ((ctx != NULL) && (next != NULL))
 115         ret = BIO_write(next, in, inl);
 116
 117     if (BIO_get_init(b)) {
 118         if (ret > 0) {
 119             if (!EVP_DigestUpdate(ctx, (const unsigned char *)in,
 120                                   (unsigned int)ret)) {
 121                 BIO_clear_retry_flags(b);
 122                 return 0;
 123             }
 124         }
 125     }
 126     if (next != NULL) {
 127         BIO_clear_retry_flags(b);
 128         BIO_copy_next_retry(b);
 129     }
 130     return ret;
 131 }
 132
 133 static long md_ctrl(BIO *b, int cmd, long num, void *ptr)
 134 {
 135     EVP_MD_CTX *ctx, *dctx, **pctx;
 136     const EVP_MD **ppmd;
 137     EVP_MD *md;
 138     long ret = 1;
 139     BIO *dbio, *next;
 140
 141
 142     ctx = BIO_get_data(b);
 143     next = BIO_next(b);
 144
 145     switch (cmd) {
 146     case BIO_CTRL_RESET:
 147         if (BIO_get_init(b))
 148             ret = EVP_DigestInit_ex(ctx, EVP_MD_CTX_md(ctx), NULL);
 149         else
 150             ret = 0;
 151         if (ret > 0)
 152             ret = BIO_ctrl(next, cmd, num, ptr);
 153         break;
 154     case BIO_C_GET_MD:
 155         if (BIO_get_init(b)) {
 156             ppmd = ptr;
 157             *ppmd = EVP_MD_CTX_md(ctx);
 158         } else
 159             ret = 0;
 160         break;
 161     case BIO_C_GET_MD_CTX:
 162         pctx = ptr;
 163         *pctx = ctx;
 164         BIO_set_init(b, 1);
 165         break;
 166     case BIO_C_SET_MD_CTX:
 167         if (BIO_get_init(b))
 168             BIO_set_data(b, ptr);
 169         else
 170             ret = 0;
 171         break;
 172     case BIO_C_DO_STATE_MACHINE:
 173         BIO_clear_retry_flags(b);
 174         ret = BIO_ctrl(next, cmd, num, ptr);
 175         BIO_copy_next_retry(b);
 176         break;
 177
 178     case BIO_C_SET_MD:
 179         md = ptr;
 180         ret = EVP_DigestInit_ex(ctx, md, NULL);
 181         if (ret > 0)
 182             BIO_set_init(b, 1);
 183         break;
 184     case BIO_CTRL_DUP:
 185         dbio = ptr;
 186         dctx = BIO_get_data(dbio);
 187         if (!EVP_MD_CTX_copy_ex(dctx, ctx))
 188             return 0;
 189         BIO_set_init(b, 1);
 190         break;
 191     default:
 192         ret = BIO_ctrl(next, cmd, num, ptr);
 193         break;
 194     }
 195     return ret;
 196 }
 197
 198 static long md_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
 199 {
 200     BIO *next;
 201
 202     next = BIO_next(b);
 203
 204     if (next == NULL)
 205         return 0;
 206
 207     return BIO_callback_ctrl(next, cmd, fp);
 208 }
 209
 210 static int md_gets(BIO *bp, char *buf, int size)
 211 {
 212     EVP_MD_CTX *ctx;
 213     unsigned int ret;
 214
 215     ctx = BIO_get_data(bp);
 216
 217     if (size < EVP_MD_CTX_size(ctx))
 218         return 0;
 219
 220     if (EVP_DigestFinal_ex(ctx, (unsigned char *)buf, &ret) <= 0)
 221         return -1;
 222
 223     return (int)ret;
 224 }