freebsd-dev/crypto/heimdal/lib/krb5/keytab_keyfile.c
2008-05-07 13:39:42 +00:00

421 lines
9.6 KiB
C

/*
* Copyright (c) 1997 - 2007 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"
RCSID("$Id: keytab_keyfile.c 20695 2007-05-30 14:09:09Z lha $");
/* afs keyfile operations --------------------------------------- */
/*
* Minimum tools to handle the AFS KeyFile.
*
* Format of the KeyFile is:
* <int32_t numkeys> {[<int32_t kvno> <char[8] deskey>] * numkeys}
*
* It just adds to the end of the keyfile, deleting isn't implemented.
* Use your favorite text/hex editor to delete keys.
*
*/
#define AFS_SERVERTHISCELL "/usr/afs/etc/ThisCell"
#define AFS_SERVERMAGICKRBCONF "/usr/afs/etc/krb.conf"
struct akf_data {
int num_entries;
char *filename;
char *cell;
char *realm;
};
/*
* set `d->cell' and `d->realm'
*/
static int
get_cell_and_realm (krb5_context context, struct akf_data *d)
{
FILE *f;
char buf[BUFSIZ], *cp;
int ret;
f = fopen (AFS_SERVERTHISCELL, "r");
if (f == NULL) {
ret = errno;
krb5_set_error_string (context, "open %s: %s", AFS_SERVERTHISCELL,
strerror(ret));
return ret;
}
if (fgets (buf, sizeof(buf), f) == NULL) {
fclose (f);
krb5_set_error_string (context, "no cell in %s", AFS_SERVERTHISCELL);
return EINVAL;
}
buf[strcspn(buf, "\n")] = '\0';
fclose(f);
d->cell = strdup (buf);
if (d->cell == NULL) {
krb5_set_error_string (context, "malloc: out of memory");
return ENOMEM;
}
f = fopen (AFS_SERVERMAGICKRBCONF, "r");
if (f != NULL) {
if (fgets (buf, sizeof(buf), f) == NULL) {
free (d->cell);
d->cell = NULL;
fclose (f);
krb5_set_error_string (context, "no realm in %s",
AFS_SERVERMAGICKRBCONF);
return EINVAL;
}
buf[strcspn(buf, "\n")] = '\0';
fclose(f);
}
/* uppercase */
for (cp = buf; *cp != '\0'; cp++)
*cp = toupper((unsigned char)*cp);
d->realm = strdup (buf);
if (d->realm == NULL) {
free (d->cell);
d->cell = NULL;
krb5_set_error_string (context, "malloc: out of memory");
return ENOMEM;
}
return 0;
}
/*
* init and get filename
*/
static krb5_error_code
akf_resolve(krb5_context context, const char *name, krb5_keytab id)
{
int ret;
struct akf_data *d = malloc(sizeof (struct akf_data));
if (d == NULL) {
krb5_set_error_string (context, "malloc: out of memory");
return ENOMEM;
}
d->num_entries = 0;
ret = get_cell_and_realm (context, d);
if (ret) {
free (d);
return ret;
}
d->filename = strdup (name);
if (d->filename == NULL) {
free (d->cell);
free (d->realm);
free (d);
krb5_set_error_string (context, "malloc: out of memory");
return ENOMEM;
}
id->data = d;
return 0;
}
/*
* cleanup
*/
static krb5_error_code
akf_close(krb5_context context, krb5_keytab id)
{
struct akf_data *d = id->data;
free (d->filename);
free (d->cell);
free (d);
return 0;
}
/*
* Return filename
*/
static krb5_error_code
akf_get_name(krb5_context context,
krb5_keytab id,
char *name,
size_t name_sz)
{
struct akf_data *d = id->data;
strlcpy (name, d->filename, name_sz);
return 0;
}
/*
* Init
*/
static krb5_error_code
akf_start_seq_get(krb5_context context,
krb5_keytab id,
krb5_kt_cursor *c)
{
int32_t ret;
struct akf_data *d = id->data;
c->fd = open (d->filename, O_RDONLY|O_BINARY, 0600);
if (c->fd < 0) {
ret = errno;
krb5_set_error_string(context, "open(%s): %s", d->filename,
strerror(ret));
return ret;
}
c->sp = krb5_storage_from_fd(c->fd);
ret = krb5_ret_int32(c->sp, &d->num_entries);
if(ret) {
krb5_storage_free(c->sp);
close(c->fd);
krb5_clear_error_string (context);
if(ret == KRB5_KT_END)
return KRB5_KT_NOTFOUND;
return ret;
}
return 0;
}
static krb5_error_code
akf_next_entry(krb5_context context,
krb5_keytab id,
krb5_keytab_entry *entry,
krb5_kt_cursor *cursor)
{
struct akf_data *d = id->data;
int32_t kvno;
off_t pos;
int ret;
pos = krb5_storage_seek(cursor->sp, 0, SEEK_CUR);
if ((pos - 4) / (4 + 8) >= d->num_entries)
return KRB5_KT_END;
ret = krb5_make_principal (context, &entry->principal,
d->realm, "afs", d->cell, NULL);
if (ret)
goto out;
ret = krb5_ret_int32(cursor->sp, &kvno);
if (ret) {
krb5_free_principal (context, entry->principal);
goto out;
}
entry->vno = kvno;
entry->keyblock.keytype = ETYPE_DES_CBC_MD5;
entry->keyblock.keyvalue.length = 8;
entry->keyblock.keyvalue.data = malloc (8);
if (entry->keyblock.keyvalue.data == NULL) {
krb5_free_principal (context, entry->principal);
krb5_set_error_string (context, "malloc: out of memory");
ret = ENOMEM;
goto out;
}
ret = krb5_storage_read(cursor->sp, entry->keyblock.keyvalue.data, 8);
if(ret != 8)
ret = (ret < 0) ? errno : KRB5_KT_END;
else
ret = 0;
entry->timestamp = time(NULL);
out:
krb5_storage_seek(cursor->sp, pos + 4 + 8, SEEK_SET);
return ret;
}
static krb5_error_code
akf_end_seq_get(krb5_context context,
krb5_keytab id,
krb5_kt_cursor *cursor)
{
krb5_storage_free(cursor->sp);
close(cursor->fd);
return 0;
}
static krb5_error_code
akf_add_entry(krb5_context context,
krb5_keytab id,
krb5_keytab_entry *entry)
{
struct akf_data *d = id->data;
int fd, created = 0;
krb5_error_code ret;
int32_t len;
krb5_storage *sp;
if (entry->keyblock.keyvalue.length != 8)
return 0;
switch(entry->keyblock.keytype) {
case ETYPE_DES_CBC_CRC:
case ETYPE_DES_CBC_MD4:
case ETYPE_DES_CBC_MD5:
break;
default:
return 0;
}
fd = open (d->filename, O_RDWR | O_BINARY);
if (fd < 0) {
fd = open (d->filename,
O_RDWR | O_BINARY | O_CREAT | O_EXCL, 0600);
if (fd < 0) {
ret = errno;
krb5_set_error_string(context, "open(%s): %s", d->filename,
strerror(ret));
return ret;
}
created = 1;
}
sp = krb5_storage_from_fd(fd);
if(sp == NULL) {
close(fd);
krb5_set_error_string (context, "malloc: out of memory");
return ENOMEM;
}
if (created)
len = 0;
else {
if(krb5_storage_seek(sp, 0, SEEK_SET) < 0) {
ret = errno;
krb5_storage_free(sp);
close(fd);
krb5_set_error_string (context, "seek: %s", strerror(ret));
return ret;
}
ret = krb5_ret_int32(sp, &len);
if(ret) {
krb5_storage_free(sp);
close(fd);
return ret;
}
}
/*
* Make sure we don't add the entry twice, assumes the DES
* encryption types are all the same key.
*/
if (len > 0) {
int32_t kvno;
int i;
for (i = 0; i < len; i++) {
ret = krb5_ret_int32(sp, &kvno);
if (ret) {
krb5_set_error_string (context, "Failed to get kvno ");
goto out;
}
if(krb5_storage_seek(sp, 8, SEEK_CUR) < 0) {
krb5_set_error_string (context, "seek: %s", strerror(ret));
goto out;
}
if (kvno == entry->vno) {
ret = 0;
goto out;
}
}
}
len++;
if(krb5_storage_seek(sp, 0, SEEK_SET) < 0) {
ret = errno;
krb5_set_error_string (context, "seek: %s", strerror(ret));
goto out;
}
ret = krb5_store_int32(sp, len);
if(ret) {
krb5_set_error_string(context, "keytab keyfile failed new length");
return ret;
}
if(krb5_storage_seek(sp, (len - 1) * (8 + 4), SEEK_CUR) < 0) {
ret = errno;
krb5_set_error_string (context, "seek to end: %s", strerror(ret));
goto out;
}
ret = krb5_store_int32(sp, entry->vno);
if(ret) {
krb5_set_error_string(context, "keytab keyfile failed store kvno");
goto out;
}
ret = krb5_storage_write(sp, entry->keyblock.keyvalue.data,
entry->keyblock.keyvalue.length);
if(ret != entry->keyblock.keyvalue.length) {
if (ret < 0)
ret = errno;
else
ret = ENOTTY;
krb5_set_error_string(context, "keytab keyfile failed to add key");
goto out;
}
ret = 0;
out:
krb5_storage_free(sp);
close (fd);
return ret;
}
const krb5_kt_ops krb5_akf_ops = {
"AFSKEYFILE",
akf_resolve,
akf_get_name,
akf_close,
NULL, /* get */
akf_start_seq_get,
akf_next_entry,
akf_end_seq_get,
akf_add_entry,
NULL /* remove */
};