OpenBSD-4.6/kerberosV/src/lib/hdb/keys.c
/*
* Copyright (c) 1997 - 2001, 2003 - 2004 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 "hdb_locl.h"
RCSID("$KTH: keys.c,v 1.3 2005/03/17 00:42:05 lha Exp $");
/*
* free all the memory used by (len, keys)
*/
void
hdb_free_keys (krb5_context context, int len, Key *keys)
{
int i;
for (i = 0; i < len; i++) {
free(keys[i].mkvno);
keys[i].mkvno = NULL;
if (keys[i].salt != NULL) {
free_Salt(keys[i].salt);
free(keys[i].salt);
keys[i].salt = NULL;
}
krb5_free_keyblock_contents(context, &keys[i].key);
}
free (keys);
}
/*
* for each entry in `default_keys' try to parse it as a sequence
* of etype:salttype:salt, syntax of this if something like:
* [(des|des3|etype):](pw-salt|afs3)[:string], if etype is omitted it
* means all etypes, and if string is omitted is means the default
* string (for that principal). Additional special values:
* v5 == pw-salt, and
* v4 == des:pw-salt:
* afs or afs3 == des:afs3-salt
*/
/* the 3 DES types must be first */
static const krb5_enctype all_etypes[] = {
ETYPE_DES_CBC_MD5,
ETYPE_DES_CBC_MD4,
ETYPE_DES_CBC_CRC,
ETYPE_AES256_CTS_HMAC_SHA1_96,
ETYPE_ARCFOUR_HMAC_MD5,
ETYPE_DES3_CBC_SHA1
};
static krb5_error_code
parse_key_set(krb5_context context, const char *key,
krb5_enctype **ret_enctypes, size_t *ret_num_enctypes,
krb5_salt *salt, krb5_principal principal)
{
const char *p;
char buf[3][256];
int num_buf = 0;
int i, num_enctypes = 0;
krb5_enctype e;
const krb5_enctype *enctypes = NULL;
krb5_error_code ret;
p = key;
*ret_enctypes = NULL;
*ret_num_enctypes = 0;
/* split p in a list of :-separated strings */
for(num_buf = 0; num_buf < 3; num_buf++)
if(strsep_copy(&p, ":", buf[num_buf], sizeof(buf[num_buf])) == -1)
break;
salt->saltvalue.data = NULL;
salt->saltvalue.length = 0;
for(i = 0; i < num_buf; i++) {
if(enctypes == NULL) {
/* this might be a etype specifier */
/* XXX there should be a string_to_etypes handling
special cases like `des' and `all' */
if(strcmp(buf[i], "des") == 0) {
enctypes = all_etypes;
num_enctypes = 3;
continue;
} else if(strcmp(buf[i], "des3") == 0) {
e = ETYPE_DES3_CBC_SHA1;
enctypes = &e;
num_enctypes = 1;
continue;
} else {
ret = krb5_string_to_enctype(context, buf[i], &e);
if (ret == 0) {
enctypes = &e;
num_enctypes = 1;
continue;
}
}
}
if(salt->salttype == 0) {
/* interpret string as a salt specifier, if no etype
is set, this sets default values */
/* XXX should perhaps use string_to_salttype, but that
interface sucks */
if(strcmp(buf[i], "pw-salt") == 0) {
if(enctypes == NULL) {
enctypes = all_etypes;
num_enctypes = sizeof(all_etypes)/sizeof(all_etypes[0]);
}
salt->salttype = KRB5_PW_SALT;
} else if(strcmp(buf[i], "afs3-salt") == 0) {
if(enctypes == NULL) {
enctypes = all_etypes;
num_enctypes = 3;
}
salt->salttype = KRB5_AFS3_SALT;
}
} else {
/* if there is a final string, use it as the string to
salt with, this is mostly useful with null salt for
v4 compat, and a cell name for afs compat */
salt->saltvalue.data = strdup(buf[i]);
if (salt->saltvalue.data == NULL) {
krb5_set_error_string(context, "malloc out of memory");
return ENOMEM;
}
salt->saltvalue.length = strlen(buf[i]);
}
}
if(enctypes == NULL || salt->salttype == 0) {
krb5_set_error_string(context, "bad value for default_keys `%s'", key);
return EINVAL;
}
/* if no salt was specified make up default salt */
if(salt->saltvalue.data == NULL) {
if(salt->salttype == KRB5_PW_SALT)
ret = krb5_get_pw_salt(context, principal, salt);
else if(salt->salttype == KRB5_AFS3_SALT) {
krb5_realm *realm = krb5_princ_realm(context, principal);
salt->saltvalue.data = strdup(*realm);
if(salt->saltvalue.data == NULL) {
krb5_set_error_string(context, "out of memory while "
"parsing salt specifiers");
return ENOMEM;
}
strlwr(salt->saltvalue.data);
salt->saltvalue.length = strlen(*realm);
}
}
*ret_enctypes = malloc(sizeof(enctypes[0]) * num_enctypes);
if (*ret_enctypes == NULL) {
krb5_free_salt(context, *salt);
krb5_set_error_string(context, "out of memory");
return ENOMEM;
}
memcpy(*ret_enctypes, enctypes, sizeof(enctypes[0]) * num_enctypes);
*ret_num_enctypes = num_enctypes;
return 0;
}
static krb5_error_code
add_enctype_to_key_set(Key **key_set, size_t *nkeyset,
krb5_enctype enctype, krb5_salt *salt)
{
krb5_error_code ret;
Key key, *tmp;
memset(&key, 0, sizeof(key));
tmp = realloc(*key_set, (*nkeyset + 1) * sizeof((*key_set)[0]));
if (tmp == NULL)
return ENOMEM;
*key_set = tmp;
key.key.keytype = enctype;
key.key.keyvalue.length = 0;
key.key.keyvalue.data = NULL;
if (salt) {
key.salt = malloc(sizeof(*key.salt));
if (key.salt == NULL) {
free_Key(&key);
return ENOMEM;
}
key.salt->type = salt->salttype;
krb5_data_zero (&key.salt->salt);
ret = krb5_data_copy(&key.salt->salt,
salt->saltvalue.data,
salt->saltvalue.length);
if (ret) {
free_Key(&key);
return ret;
}
} else
key.salt = NULL;
(*key_set)[*nkeyset] = key;
*nkeyset += 1;
return 0;
}
/*
* Generate the `key_set' from the [kadmin]default_keys statement. If
* `no_salt' is set, salt is not important (and will not be set) since
* its random keys that is going to be created.
*/
krb5_error_code
hdb_generate_key_set(krb5_context context, krb5_principal principal,
Key **ret_key_set, size_t *nkeyset, int no_salt)
{
char **ktypes, **kp;
krb5_error_code ret;
Key *k, *key_set;
int i, j;
char *default_keytypes[] = {
"des:pw-salt",
"aes256-cts-hmac-sha1-96:pw-salt",
"des3-cbc-sha1:pw-salt",
"arcfour-hmac-md5:pw-salt",
NULL
};
ktypes = krb5_config_get_strings(context, NULL, "kadmin",
"default_keys", NULL);
if (ktypes == NULL)
ktypes = default_keytypes;
if (ktypes == NULL)
abort();
*ret_key_set = key_set = NULL;
*nkeyset = 0;
ret = 0;
for(kp = ktypes; kp && *kp; kp++) {
const char *p;
krb5_salt salt;
krb5_enctype *enctypes;
size_t num_enctypes;
p = *kp;
/* check alias */
if(strcmp(p, "v5") == 0)
p = "pw-salt";
else if(strcmp(p, "v4") == 0)
p = "des:pw-salt:";
else if(strcmp(p, "afs") == 0 || strcmp(p, "afs3") == 0)
p = "des:afs3-salt";
else if (strcmp(p, "arcfour-hmac-md5") == 0)
p = "arcfour-hmac-md5:pw-salt";
memset(&salt, 0, sizeof(salt));
ret = parse_key_set(context, p,
&enctypes, &num_enctypes, &salt, principal);
if (ret) {
krb5_warnx(context, "bad value for default_keys `%s'", *kp);
continue;
}
for (i = 0; i < num_enctypes; i++) {
/* find duplicates */
for (j = 0; j < *nkeyset; j++) {
k = &key_set[j];
if (k->key.keytype == enctypes[i]) {
if (no_salt)
break;
if (k->salt == NULL && salt.salttype == KRB5_PW_SALT)
break;
if (k->salt->type == salt.salttype &&
k->salt->salt.length == salt.saltvalue.length &&
memcmp(k->salt->salt.data, salt.saltvalue.data,
salt.saltvalue.length) == 0)
break;
}
}
/* not a duplicate, lets add it */
if (j == *nkeyset) {
ret = add_enctype_to_key_set(&key_set, nkeyset, enctypes[i],
no_salt ? NULL : &salt);
if (ret) {
free(enctypes);
krb5_free_salt(context, salt);
goto out;
}
}
}
free(enctypes);
krb5_free_salt(context, salt);
}
out:
if (ret) {
krb5_warn(context, ret,
"failed to parse the [kadmin]default_keys values");
for (i = 0; i < *nkeyset; i++)
free_Key(&key_set[i]);
free(key_set);
} else if (*nkeyset == 0) {
krb5_warnx(context,
"failed to parse any of the [kadmin]default_keys values");
ret = EINVAL; /* XXX */
}
*ret_key_set = key_set;
return ret;
}
krb5_error_code
hdb_generate_key_set_password(krb5_context context,
krb5_principal principal,
const char *password,
Key **keys, size_t *num_keys)
{
krb5_error_code ret;
int i;
ret = hdb_generate_key_set(context, principal,
keys, num_keys, 0);
if (ret)
return ret;
for (i = 0; i < (*num_keys); i++) {
krb5_salt salt;
salt.salttype = (*keys)[i].salt->type;
salt.saltvalue.length = (*keys)[i].salt->salt.length;
salt.saltvalue.data = (*keys)[i].salt->salt.data;
ret = krb5_string_to_key_salt (context,
(*keys)[i].key.keytype,
password,
salt,
&(*keys)[i].key);
if(ret)
break;
}
if(ret) {
hdb_free_keys (context, *num_keys, *keys);
return ret;
}
return ret;
}