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/*
* Copyright (c) 2000 - 2001 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"
#ifndef O_BINARY
#define O_BINARY 0
#endif
RCSID("$Id: mkey.c,v 1.8 2001/01/30 01:20:57 assar Exp $");
struct hdb_master_key_data {
krb5_keytab_entry keytab;
krb5_crypto crypto;
struct hdb_master_key_data *next;
};
void
hdb_free_master_key(krb5_context context, hdb_master_key mkey)
{
struct hdb_master_key_data *ptr;
while(mkey) {
krb5_kt_free_entry(context, &mkey->keytab);
krb5_crypto_destroy(context, mkey->crypto);
ptr = mkey;
mkey = mkey->next;
free(ptr);
}
}
krb5_error_code
hdb_process_master_key(krb5_context context,
int kvno, krb5_keyblock *key, krb5_enctype etype,
hdb_master_key *mkey)
{
krb5_error_code ret;
*mkey = calloc(1, sizeof(**mkey));
if(*mkey == NULL)
return ENOMEM;
(*mkey)->keytab.vno = kvno;
ret = krb5_parse_name(context, "K/M", &(*mkey)->keytab.principal);
ret = krb5_copy_keyblock_contents(context, key, &(*mkey)->keytab.keyblock);
if(ret) {
free(*mkey);
*mkey = NULL;
return ret;
}
if(etype != 0)
(*mkey)->keytab.keyblock.keytype = etype;
(*mkey)->keytab.timestamp = time(NULL);
ret = krb5_crypto_init(context, key, etype, &(*mkey)->crypto);
if(ret) {
krb5_free_keyblock_contents(context, &(*mkey)->keytab.keyblock);
free(*mkey);
*mkey = NULL;
}
return ret;
}
krb5_error_code
hdb_add_master_key(krb5_context context, krb5_keyblock *key,
hdb_master_key *inout)
{
int vno = 0;
hdb_master_key p;
krb5_error_code ret;
for(p = *inout; p; p = p->next)
vno = max(vno, p->keytab.vno);
vno++;
ret = hdb_process_master_key(context, vno, key, 0, &p);
if(ret)
return ret;
p->next = *inout;
*inout = p;
return 0;
}
static krb5_error_code
read_master_keytab(krb5_context context, const char *filename,
hdb_master_key *mkey)
{
krb5_error_code ret;
krb5_keytab id;
krb5_kt_cursor cursor;
krb5_keytab_entry entry;
hdb_master_key p;
ret = krb5_kt_resolve(context, filename, &id);
if(ret)
return ret;
ret = krb5_kt_start_seq_get(context, id, &cursor);
if(ret)
goto out;
*mkey = NULL;
while(krb5_kt_next_entry(context, id, &entry, &cursor) == 0) {
p = calloc(1, sizeof(*p));
p->keytab = entry;
ret = krb5_crypto_init(context, &p->keytab.keyblock, 0, &p->crypto);
p->next = *mkey;
*mkey = p;
}
krb5_kt_end_seq_get(context, id, &cursor);
out:
krb5_kt_close(context, id);
return ret;
}
/* read a MIT master keyfile */
static krb5_error_code
read_master_mit(krb5_context context, const char *filename,
hdb_master_key *mkey)
{
int fd;
krb5_error_code ret;
krb5_storage *sp;
u_int16_t enctype;
krb5_keyblock key;
fd = open(filename, O_RDONLY | O_BINARY);
if(fd < 0)
return errno;
sp = krb5_storage_from_fd(fd);
if(sp == NULL) {
close(fd);
return errno;
}
krb5_storage_set_flags(sp, KRB5_STORAGE_HOST_BYTEORDER);
#if 0
/* could possibly use ret_keyblock here, but do it with more
checks for now */
ret = krb5_ret_keyblock(sp, &key);
#else
ret = krb5_ret_int16(sp, &enctype);
if((htons(enctype) & 0xff00) == 0x3000) {
ret = HEIM_ERR_BAD_MKEY;
goto out;
}
key.keytype = enctype;
ret = krb5_ret_data(sp, &key.keyvalue);
if(ret)
goto out;
#endif
ret = hdb_process_master_key(context, 0, &key, 0, mkey);
krb5_free_keyblock_contents(context, &key);
out:
krb5_storage_free(sp);
close(fd);
return ret;
}
/* read an old master key file */
static krb5_error_code
read_master_encryptionkey(krb5_context context, const char *filename,
hdb_master_key *mkey)
{
int fd;
krb5_keyblock key;
krb5_error_code ret;
unsigned char buf[256];
ssize_t len;
fd = open(filename, O_RDONLY | O_BINARY);
if(fd < 0)
return errno;
len = read(fd, buf, sizeof(buf));
close(fd);
if(len < 0)
return errno;
ret = decode_EncryptionKey(buf, len, &key, &len);
memset(buf, 0, sizeof(buf));
if(ret)
return ret;
/* Originally, the keytype was just that, and later it got changed
to des-cbc-md5, but we always used des in cfb64 mode. This
should cover all cases, but will break if someone has hacked
this code to really use des-cbc-md5 -- but then that's not my
problem. */
if(key.keytype == KEYTYPE_DES || key.keytype == ETYPE_DES_CBC_MD5)
key.keytype = ETYPE_DES_CFB64_NONE;
ret = hdb_process_master_key(context, 0, &key, 0, mkey);
krb5_free_keyblock_contents(context, &key);
return ret;
}
/* read a krb4 /.k style file */
static krb5_error_code
read_master_krb4(krb5_context context, const char *filename,
hdb_master_key *mkey)
{
int fd;
krb5_keyblock key;
krb5_error_code ret;
unsigned char buf[256];
ssize_t len;
fd = open(filename, O_RDONLY | O_BINARY);
if(fd < 0)
return errno;
len = read(fd, buf, sizeof(buf));
close(fd);
if(len < 0)
return errno;
memset(&key, 0, sizeof(key));
key.keytype = ETYPE_DES_PCBC_NONE;
ret = krb5_data_copy(&key.keyvalue, buf, len);
memset(buf, 0, sizeof(buf));
if(ret)
return ret;
ret = hdb_process_master_key(context, 0, &key, 0, mkey);
krb5_free_keyblock_contents(context, &key);
return ret;
}
krb5_error_code
hdb_read_master_key(krb5_context context, const char *filename,
hdb_master_key *mkey)
{
FILE *f;
unsigned char buf[16];
krb5_error_code ret;
off_t len;
*mkey = NULL;
if(filename == NULL)
filename = HDB_DB_DIR "/m-key";
f = fopen(filename, "r");
if(f == NULL)
return errno;
if(fread(buf, 1, 2, f) != 2) {
fclose(f);
return HEIM_ERR_EOF;
}
fseek(f, 0, SEEK_END);
len = ftell(f);
if(fclose(f) != 0)
return errno;
if(len < 0)
return errno;
if(len == 8) {
ret = read_master_krb4(context, filename, mkey);
} else if(buf[0] == 0x30 && len <= 127 && buf[1] == len - 2) {
ret = read_master_encryptionkey(context, filename, mkey);
} else if(buf[0] == 5 && buf[1] >= 1 && buf[1] <= 2) {
ret = read_master_keytab(context, filename, mkey);
} else {
ret = read_master_mit(context, filename, mkey);
}
return ret;
}
krb5_error_code
hdb_write_master_key(krb5_context context, const char *filename,
hdb_master_key mkey)
{
krb5_error_code ret;
hdb_master_key p;
krb5_keytab kt;
if(filename == NULL)
filename = HDB_DB_DIR "/m-key";
ret = krb5_kt_resolve(context, filename, &kt);
if(ret)
return ret;
for(p = mkey; p; p = p->next) {
ret = krb5_kt_add_entry(context, kt, &p->keytab);
}
krb5_kt_close(context, kt);
return ret;
}
static hdb_master_key
find_master_key(Key *key, hdb_master_key mkey)
{
hdb_master_key ret = NULL;
while(mkey) {
if(ret == NULL && mkey->keytab.vno == 0)
ret = mkey;
if(key->mkvno == NULL) {
if(ret == NULL || mkey->keytab.vno > ret->keytab.vno)
ret = mkey;
} else if(mkey->keytab.vno == *key->mkvno)
return mkey;
mkey = mkey->next;
}
return ret;
}
krb5_error_code
hdb_unseal_keys_mkey(krb5_context context, hdb_entry *ent, hdb_master_key mkey)
{
int i;
krb5_error_code ret;
krb5_data res;
Key *k;
for(i = 0; i < ent->keys.len; i++){
hdb_master_key key;
k = &ent->keys.val[i];
if(k->mkvno == NULL)
continue;
key = find_master_key(&ent->keys.val[i], mkey);
if (key == NULL)
return HDB_ERR_NO_MKEY;
ret = krb5_decrypt(context, key->crypto, HDB_KU_MKEY,
k->key.keyvalue.data,
k->key.keyvalue.length,
&res);
if (ret)
return ret;
memset(k->key.keyvalue.data, 0, k->key.keyvalue.length);
free(k->key.keyvalue.data);
k->key.keyvalue = res;
free(k->mkvno);
k->mkvno = NULL;
}
return 0;
}
krb5_error_code
hdb_unseal_keys(krb5_context context, HDB *db, hdb_entry *ent)
{
if (db->master_key_set == 0)
return 0;
return hdb_unseal_keys_mkey(context, ent, db->master_key);
}
krb5_error_code
hdb_seal_keys_mkey(krb5_context context, hdb_entry *ent, hdb_master_key mkey)
{
int i;
krb5_error_code ret;
krb5_data res;
for(i = 0; i < ent->keys.len; i++){
Key *k = &ent->keys.val[i];
hdb_master_key key;
if(k->mkvno != NULL)
continue;
key = find_master_key(k, mkey);
if (key == NULL)
return HDB_ERR_NO_MKEY;
ret = krb5_encrypt(context, key->crypto, HDB_KU_MKEY,
k->key.keyvalue.data,
k->key.keyvalue.length,
&res);
if (ret)
return ret;
memset(k->key.keyvalue.data, 0, k->key.keyvalue.length);
free(k->key.keyvalue.data);
k->key.keyvalue = res;
k->mkvno = malloc(sizeof(*k->mkvno));
if (k->mkvno == NULL)
return ENOMEM;
*k->mkvno = key->keytab.vno;
}
return 0;
}
krb5_error_code
hdb_seal_keys(krb5_context context, HDB *db, hdb_entry *ent)
{
if (db->master_key_set == 0)
return 0;
return hdb_seal_keys_mkey(context, ent, db->master_key);
}
krb5_error_code
hdb_set_master_key (krb5_context context,
HDB *db,
krb5_keyblock *key)
{
krb5_error_code ret;
hdb_master_key mkey;
ret = hdb_process_master_key(context, 0, key, 0, &mkey);
if (ret)
return ret;
db->master_key = mkey;
#if 0 /* XXX - why? */
des_set_random_generator_seed(key.keyvalue.data);
#endif
db->master_key_set = 1;
return 0;
}
krb5_error_code
hdb_set_master_keyfile (krb5_context context,
HDB *db,
const char *keyfile)
{
hdb_master_key key;
krb5_error_code ret;
ret = hdb_read_master_key(context, keyfile, &key);
if (ret) {
if (ret != ENOENT)
return ret;
return 0;
}
db->master_key = key;
db->master_key_set = 1;
return ret;
}
krb5_error_code
hdb_clear_master_key (krb5_context context,
HDB *db)
{
if (db->master_key_set) {
hdb_free_master_key(context, db->master_key);
db->master_key_set = 0;
}
return 0;
}
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