lib/krb5/crypto-des-common.c

   1 /*
   2  * Copyright (c) 1997 - 2008 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /* Functions which are used by both single and triple DES enctypes */
  35
  36 #include "krb5_locl.h"
  37
  38 /*
  39  * A = A xor B. A & B are 8 bytes.
  40  */
  41
  42 KRB5_LIB_FUNCTION void KRB5_LIB_CALL
  43 _krb5_xor8(unsigned char *a, const unsigned char *b)
  44 {
  45     a[0] ^= b[0];
  46     a[1] ^= b[1];
  47     a[2] ^= b[2];
  48     a[3] ^= b[3];
  49     a[4] ^= b[4];
  50     a[5] ^= b[5];
  51     a[6] ^= b[6];
  52     a[7] ^= b[7];
  53 }
  54
  55 #if defined(DES3_OLD_ENCTYPE) || defined(HEIM_WEAK_CRYPTO)
  56 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
  57 _krb5_des_checksum(krb5_context context,
  58                    const EVP_MD *evp_md,
  59                    struct _krb5_key_data *key,
  60                    const struct krb5_crypto_iov *iov,
  61                    int niov,
  62                    Checksum *cksum)
  63 {
  64     struct _krb5_evp_schedule *ctx = key->schedule->data;
  65     EVP_MD_CTX *m;
  66     DES_cblock ivec;
  67     int i;
  68     unsigned char *p = cksum->checksum.data;
  69
  70     krb5_generate_random_block(p, 8);
  71
  72     m = EVP_MD_CTX_create();
  73     if (m == NULL)
  74         return krb5_enomem(context);
  75
  76     EVP_DigestInit_ex(m, evp_md, NULL);
  77     EVP_DigestUpdate(m, p, 8);
  78     for (i = 0; i < niov; i++) {
  79         if (_krb5_crypto_iov_should_sign(&iov[i]))
  80             EVP_DigestUpdate(m, iov[i].data.data, iov[i].data.length);
  81     }
  82     EVP_DigestFinal_ex (m, p + 8, NULL);
  83     EVP_MD_CTX_destroy(m);
  84     memset_s(&ivec, sizeof(ivec), 0, sizeof(ivec));
  85     EVP_CipherInit_ex(&ctx->ectx, NULL, NULL, NULL, (void *)&ivec, -1);
  86     EVP_Cipher(&ctx->ectx, p, p, 24);
  87
  88     return 0;
  89 }
  90
  91 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
  92 _krb5_des_verify(krb5_context context,
  93                  const EVP_MD *evp_md,
  94                  struct _krb5_key_data *key,
  95                  const struct krb5_crypto_iov *iov,
  96                  int niov,
  97                  Checksum *C)
  98 {
  99     struct _krb5_evp_schedule *ctx = key->schedule->data;
 100     EVP_MD_CTX *m;
 101     unsigned char tmp[24];
 102     unsigned char res[16];
 103     DES_cblock ivec;
 104     krb5_error_code ret = 0;
 105     int i;
 106
 107     m = EVP_MD_CTX_create();
 108     if (m == NULL)
 109         return krb5_enomem(context);
 110
 111     memset_s(&ivec, sizeof(ivec), 0, sizeof(ivec));
 112     EVP_CipherInit_ex(&ctx->dctx, NULL, NULL, NULL, (void *)&ivec, -1);
 113     EVP_Cipher(&ctx->dctx, tmp, C->checksum.data, 24);
 114
 115     EVP_DigestInit_ex(m, evp_md, NULL);
 116     EVP_DigestUpdate(m, tmp, 8); /* confounder */
 117     for (i = 0; i < niov; i++) {
 118         if (_krb5_crypto_iov_should_sign(&iov[i]))
 119             EVP_DigestUpdate(m, iov[i].data.data, iov[i].data.length);
 120     }
 121     EVP_DigestFinal_ex (m, res, NULL);
 122     EVP_MD_CTX_destroy(m);
 123     if(ct_memcmp(res, tmp + 8, sizeof(res)) != 0) {
 124         krb5_clear_error_message (context);
 125         ret = KRB5KRB_AP_ERR_BAD_INTEGRITY;
 126     }
 127     memset_s(tmp, sizeof(tmp), 0, sizeof(tmp));
 128     memset_s(res, sizeof(res), 0, sizeof(res));
 129     return ret;
 130 }
 131
 132 #endif
 133
 134 static krb5_error_code
 135 RSA_MD5_checksum(krb5_context context,
 136                  krb5_crypto crypto,
 137                  struct _krb5_key_data *key,
 138                  unsigned usage,
 139                  const struct krb5_crypto_iov *iov,
 140                  int niov,
 141                  Checksum *C)
 142 {
 143     if (_krb5_evp_digest_iov(crypto, iov, niov, C->checksum.data,
 144                              NULL, EVP_md5(), NULL) != 1)
 145         krb5_abortx(context, "md5 checksum failed");
 146
 147     return 0;
 148 }
 149
 150 struct _krb5_checksum_type _krb5_checksum_rsa_md5 = {
 151     CKSUMTYPE_RSA_MD5,
 152     "rsa-md5",
 153     64,
 154     16,
 155     F_CPROOF,
 156     RSA_MD5_checksum,
 157     NULL
 158 };