/*

 * Copyright (c) 1997 - 2008 Kungliga Tekniska Högskolan

 * (Royal Institute of Technology, Stockholm, Sweden).

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 *

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * 3. Neither the name of the Institute nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 */

/* Functions which are used by both single and triple DES enctypes */

#include "krb5_locl.h"

/*

 * A = A xor B. A & B are 8 bytes.

 */

KRB5_LIB_FUNCTION void KRB5_LIB_CALL

_krb5_xor8(unsigned char *a, const unsigned char *b)

{

    a[0] ^= b[0];

    a[1] ^= b[1];

    a[2] ^= b[2];

    a[3] ^= b[3];

    a[4] ^= b[4];

    a[5] ^= b[5];

    a[6] ^= b[6];

    a[7] ^= b[7];

}

#if defined(DES3_OLD_ENCTYPE) || defined(HEIM_WEAK_CRYPTO)

KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL

_krb5_des_checksum(krb5_context context,

       const EVP_MD *evp_md,

       struct _krb5_key_data *key,

       const struct krb5_crypto_iov *iov,

       int niov,

       Checksum *cksum)

{

    struct _krb5_evp_schedule *ctx = key->schedule->data;

    EVP_MD_CTX *m;

    DES_cblock ivec;

    int i;

    unsigned char *p = cksum->checksum.data;

    krb5_generate_random_block(p, 8);

    m = EVP_MD_CTX_create();

    if (m == NULL)

  return krb5_enomem(context);

    EVP_DigestInit_ex(m, evp_md, NULL);

    EVP_DigestUpdate(m, p, 8);

    for (i = 0; i < niov; i++) {

  if (_krb5_crypto_iov_should_sign(&iov[i]))

      EVP_DigestUpdate(m, iov[i].data.data, iov[i].data.length);

    }

    EVP_DigestFinal_ex (m, p + 8, NULL);

    EVP_MD_CTX_destroy(m);

    memset_s(&ivec, sizeof(ivec), 0, sizeof(ivec));

    EVP_CipherInit_ex(&ctx->ectx, NULL, NULL, NULL, (void *)&ivec, -1);

    EVP_Cipher(&ctx->ectx, p, p, 24);

    return 0;

}

KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL

_krb5_des_verify(krb5_context context,

     const EVP_MD *evp_md,

     struct _krb5_key_data *key,

     const struct krb5_crypto_iov *iov,

     int niov,

     Checksum *C)

{

    struct _krb5_evp_schedule *ctx = key->schedule->data;

    EVP_MD_CTX *m;

    unsigned char tmp[24];

    unsigned char res[16];

    DES_cblock ivec;

    krb5_error_code ret = 0;

    int i;

    m = EVP_MD_CTX_create();

    if (m == NULL)

  return krb5_enomem(context);

    memset_s(&ivec, sizeof(ivec), 0, sizeof(ivec));

    EVP_CipherInit_ex(&ctx->dctx, NULL, NULL, NULL, (void *)&ivec, -1);

    EVP_Cipher(&ctx->dctx, tmp, C->checksum.data, 24);

    EVP_DigestInit_ex(m, evp_md, NULL);

    EVP_DigestUpdate(m, tmp, 8); /* confounder */

    for (i = 0; i < niov; i++) {

  if (_krb5_crypto_iov_should_sign(&iov[i]))

      EVP_DigestUpdate(m, iov[i].data.data, iov[i].data.length);

    }

    EVP_DigestFinal_ex (m, res, NULL);

    EVP_MD_CTX_destroy(m);

    if(ct_memcmp(res, tmp + 8, sizeof(res)) != 0) {

  krb5_clear_error_message (context);

  ret = KRB5KRB_AP_ERR_BAD_INTEGRITY;

    }

    memset_s(tmp, sizeof(tmp), 0, sizeof(tmp));

    memset_s(res, sizeof(res), 0, sizeof(res));

    return ret;

}

#endif

static krb5_error_code

RSA_MD5_checksum(krb5_context context,

     krb5_crypto crypto,

     struct _krb5_key_data *key,

     unsigned usage,

     const struct krb5_crypto_iov *iov,

     int niov,

     Checksum *C)

{

    if (_krb5_evp_digest_iov(crypto, iov, niov, C->checksum.data,

           NULL, EVP_md5(), NULL) != 1)

  krb5_abortx(context, "md5 checksum failed");

    return 0;

}

struct _krb5_checksum_type _krb5_checksum_rsa_md5 = {

    CKSUMTYPE_RSA_MD5,

    "rsa-md5",

    64,

    16,

    F_CPROOF,

    RSA_MD5_checksum,

    NULL

};