/* $NetBSD: salt-des.c,v 1.2 2017/01/28 21:31:49 christos Exp $ */
/*
* 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.
*/
#include "krb5_locl.h"
#ifdef HEIM_WEAK_CRYPTO
#ifdef ENABLE_AFS_STRING_TO_KEY
/* This defines the Andrew string_to_key function. It accepts a password
* string as input and converts it via a one-way encryption algorithm to a DES
* encryption key. It is compatible with the original Andrew authentication
* service password database.
*/
/*
* Short passwords, i.e 8 characters or less.
*/
static void
krb5_DES_AFS3_CMU_string_to_key (krb5_data pw,
krb5_data cell,
DES_cblock *key)
{
char password[8+1]; /* crypt is limited to 8 chars anyway */
size_t i;
for(i = 0; i < 8; i++) {
char c = ((i < pw.length) ? ((char*)pw.data)[i] : 0) ^
((i < cell.length) ?
tolower(((unsigned char*)cell.data)[i]) : 0);
password[i] = c ? c : 'X';
}
password[8] = '\0';
memcpy(key, crypt(password, "p1") + 2, sizeof(DES_cblock));
/* parity is inserted into the LSB so left shift each byte up one
bit. This allows ascii characters with a zero MSB to retain as
much significance as possible. */
for (i = 0; i < sizeof(DES_cblock); i++)
((unsigned char*)key)[i] <<= 1;
DES_set_odd_parity (key);
}
/*
* Long passwords, i.e 9 characters or more.
*/
static void
krb5_DES_AFS3_Transarc_string_to_key (krb5_data pw,
krb5_data cell,
DES_cblock *key)
{
DES_key_schedule schedule;
DES_cblock temp_key;
DES_cblock ivec;
char password[512];
size_t passlen;
memcpy(password, pw.data, min(pw.length, sizeof(password)));
if(pw.length < sizeof(password)) {
int len = min(cell.length, sizeof(password) - pw.length);
size_t i;
memcpy(password + pw.length, cell.data, len);
for (i = pw.length; i < pw.length + len; ++i)
password[i] = tolower((unsigned char)password[i]);
}
passlen = min(sizeof(password), pw.length + cell.length);
memcpy(&ivec, "kerberos", 8);
memcpy(&temp_key, "kerberos", 8);
DES_set_odd_parity (&temp_key);
DES_set_key_unchecked (&temp_key, &schedule);
DES_cbc_cksum ((void*)password, &ivec, passlen, &schedule, &ivec);
memcpy(&temp_key, &ivec, 8);
DES_set_odd_parity (&temp_key);
DES_set_key_unchecked (&temp_key, &schedule);
DES_cbc_cksum ((void*)password, key, passlen, &schedule, &ivec);
memset(&schedule, 0, sizeof(schedule));
memset(&temp_key, 0, sizeof(temp_key));
memset(&ivec, 0, sizeof(ivec));
memset(password, 0, sizeof(password));
DES_set_odd_parity (key);
}
static krb5_error_code
DES_AFS3_string_to_key(krb5_context context,
krb5_enctype enctype,
krb5_data password,
krb5_salt salt,
krb5_data opaque,
krb5_keyblock *key)
{
DES_cblock tmp;
if(password.length > 8)
krb5_DES_AFS3_Transarc_string_to_key(password, salt.saltvalue, &tmp);
else
krb5_DES_AFS3_CMU_string_to_key(password, salt.saltvalue, &tmp);
key->keytype = enctype;
krb5_data_copy(&key->keyvalue, tmp, sizeof(tmp));
memset(&key, 0, sizeof(key));
return 0;
}
#endif /* ENABLE_AFS_STRING_TO_KEY */
static void
DES_string_to_key_int(unsigned char *data, size_t length, DES_cblock *key)
{
DES_key_schedule schedule;
size_t i;
int reverse = 0;
unsigned char *p;
unsigned char swap[] = { 0x0, 0x8, 0x4, 0xc, 0x2, 0xa, 0x6, 0xe,
0x1, 0x9, 0x5, 0xd, 0x3, 0xb, 0x7, 0xf };
memset(key, 0, 8);
p = (unsigned char*)key;
for (i = 0; i < length; i++) {
unsigned char tmp = data[i];
if (!reverse)
*p++ ^= (tmp << 1);
else
*--p ^= (swap[tmp & 0xf] << 4) | swap[(tmp & 0xf0) >> 4];
if((i % 8) == 7)
reverse = !reverse;
}
DES_set_odd_parity(key);
if(DES_is_weak_key(key))
(*key)[7] ^= 0xF0;
DES_set_key_unchecked(key, &schedule);
DES_cbc_cksum((void*)data, key, length, &schedule, key);
memset(&schedule, 0, sizeof(schedule));
DES_set_odd_parity(key);
if(DES_is_weak_key(key))
(*key)[7] ^= 0xF0;
}
static krb5_error_code
krb5_DES_string_to_key(krb5_context context,
krb5_enctype enctype,
krb5_data password,
krb5_salt salt,
krb5_data opaque,
krb5_keyblock *key)
{
unsigned char *s;
size_t len;
DES_cblock tmp;
#ifdef ENABLE_AFS_STRING_TO_KEY
if (opaque.length == 1) {
unsigned long v;
_krb5_get_int(opaque.data, &v, 1);
if (v == 1)
return DES_AFS3_string_to_key(context, enctype, password,
salt, opaque, key);
}
#endif
len = password.length + salt.saltvalue.length;
s = malloc(len);
if (len > 0 && s == NULL)
return krb5_enomem(context);
memcpy(s, password.data, password.length);
memcpy(s + password.length, salt.saltvalue.data, salt.saltvalue.length);
DES_string_to_key_int(s, len, &tmp);
key->keytype = enctype;
krb5_data_copy(&key->keyvalue, tmp, sizeof(tmp));
memset(&tmp, 0, sizeof(tmp));
memset(s, 0, len);
free(s);
return 0;
}
struct salt_type _krb5_des_salt[] = {
{
KRB5_PW_SALT,
"pw-salt",
krb5_DES_string_to_key
},
#ifdef ENABLE_AFS_STRING_TO_KEY
{
KRB5_AFS3_SALT,
"afs3-salt",
DES_AFS3_string_to_key
},
#endif
{ 0, NULL, NULL }
};
#endif