OpenBSD-4.6/kerberosV/src/lib/krb5/fcache.c
/*
* Copyright (c) 1997 - 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 "krb5_locl.h"
RCSID("$KTH: fcache.c,v 1.48 2005/05/31 22:06:15 lha Exp $");
typedef struct krb5_fcache{
char *filename;
int version;
}krb5_fcache;
struct fcc_cursor {
int fd;
krb5_storage *sp;
};
#define KRB5_FCC_FVNO_1 1
#define KRB5_FCC_FVNO_2 2
#define KRB5_FCC_FVNO_3 3
#define KRB5_FCC_FVNO_4 4
#define FCC_TAG_DELTATIME 1
#define FCACHE(X) ((krb5_fcache*)(X)->data.data)
#define FILENAME(X) (FCACHE(X)->filename)
#define FCC_CURSOR(C) ((struct fcc_cursor*)(C))
static const char*
fcc_get_name(krb5_context context,
krb5_ccache id)
{
return FILENAME(id);
}
int
_krb5_xlock(krb5_context context, int fd, krb5_boolean exclusive,
const char *filename)
{
int ret;
#ifdef HAVE_FCNTL
struct flock l;
l.l_start = 0;
l.l_len = 0;
l.l_type = exclusive ? F_WRLCK : F_RDLCK;
l.l_whence = SEEK_SET;
ret = fcntl(fd, F_SETLKW, &l);
#else
ret = flock(fd, exclusive ? LOCK_EX : LOCK_SH);
#endif
if(ret < 0)
ret = errno;
if(ret == EACCES) /* fcntl can return EACCES instead of EAGAIN */
ret = EAGAIN;
switch (ret) {
case 0:
break;
case EINVAL: /* filesystem doesn't support locking, let the user have it */
ret = 0;
break;
case EAGAIN:
krb5_set_error_string(context, "timed out locking cache file %s",
filename);
break;
default:
krb5_set_error_string(context, "error locking cache file %s: %s",
filename, strerror(ret));
break;
}
return ret;
}
int
_krb5_xunlock(krb5_context context, int fd)
{
int ret;
#ifdef HAVE_FCNTL_LOCK
struct flock l;
l.l_start = 0;
l.l_len = 0;
l.l_type = F_UNLCK;
l.l_whence = SEEK_SET;
ret = fcntl(fd, F_SETLKW, &l);
#else
ret = flock(fd, LOCK_UN);
#endif
if (ret < 0)
ret = errno;
switch (ret) {
case 0:
break;
case EINVAL: /* filesystem doesn't support locking, let the user have it */
ret = 0;
break;
default:
krb5_set_error_string(context,
"Failed to unlock file: %s", strerror(ret));
break;
}
return ret;
}
static krb5_error_code
fcc_lock(krb5_context context, krb5_ccache id,
int fd, krb5_boolean exclusive)
{
return _krb5_xlock(context, fd, exclusive, fcc_get_name(context, id));
}
static krb5_error_code
fcc_unlock(krb5_context context, int fd)
{
return _krb5_xunlock(context, fd);
}
static krb5_error_code
fcc_resolve(krb5_context context, krb5_ccache *id, const char *res)
{
krb5_fcache *f;
f = malloc(sizeof(*f));
if(f == NULL) {
krb5_set_error_string(context, "malloc: out of memory");
return KRB5_CC_NOMEM;
}
f->filename = strdup(res);
if(f->filename == NULL){
free(f);
krb5_set_error_string(context, "malloc: out of memory");
return KRB5_CC_NOMEM;
}
f->version = 0;
(*id)->data.data = f;
(*id)->data.length = sizeof(*f);
return 0;
}
/*
* Try to scrub the contents of `filename' safely.
*/
static int
scrub_file (int fd)
{
off_t pos;
char buf[128];
pos = lseek(fd, 0, SEEK_END);
if (pos < 0)
return errno;
if (lseek(fd, 0, SEEK_SET) < 0)
return errno;
memset(buf, 0, sizeof(buf));
while(pos > 0) {
ssize_t tmp = write(fd, buf, min(sizeof(buf), pos));
if (tmp < 0)
return errno;
pos -= tmp;
}
fsync (fd);
return 0;
}
/*
* Erase `filename' if it exists, trying to remove the contents if
* it's `safe'. We always try to remove the file, it it exists. It's
* only overwritten if it's a regular file (not a symlink and not a
* hardlink)
*/
static krb5_error_code
erase_file(const char *filename)
{
int fd;
struct stat sb1, sb2;
int ret;
ret = lstat (filename, &sb1);
if (ret < 0)
return errno;
fd = open(filename, O_RDWR | O_BINARY);
if(fd < 0) {
if(errno == ENOENT)
return 0;
else
return errno;
}
if (unlink(filename) < 0) {
close (fd);
return errno;
}
ret = fstat (fd, &sb2);
if (ret < 0) {
close (fd);
return errno;
}
/* check if someone was playing with symlinks */
if (sb1.st_dev != sb2.st_dev || sb1.st_ino != sb2.st_ino) {
close (fd);
return EPERM;
}
/* there are still hard links to this file */
if (sb2.st_nlink != 0) {
close (fd);
return 0;
}
ret = scrub_file (fd);
close (fd);
return ret;
}
static krb5_error_code
fcc_gen_new(krb5_context context, krb5_ccache *id)
{
krb5_fcache *f;
int fd;
char *file;
f = malloc(sizeof(*f));
if(f == NULL) {
krb5_set_error_string(context, "malloc: out of memory");
return KRB5_CC_NOMEM;
}
asprintf (&file, "%sXXXXXXXXXX", KRB5_DEFAULT_CCFILE_ROOT);
if(file == NULL) {
free(f);
krb5_set_error_string(context, "malloc: out of memory");
return KRB5_CC_NOMEM;
}
fd = mkstemp(file);
if(fd < 0) {
free(f);
free(file);
krb5_set_error_string(context, "mkstemp %s", file);
return errno;
}
close(fd);
f->filename = file;
f->version = 0;
(*id)->data.data = f;
(*id)->data.length = sizeof(*f);
return 0;
}
static void
storage_set_flags(krb5_context context, krb5_storage *sp, int vno)
{
int flags = 0;
switch(vno) {
case KRB5_FCC_FVNO_1:
flags |= KRB5_STORAGE_PRINCIPAL_WRONG_NUM_COMPONENTS;
flags |= KRB5_STORAGE_PRINCIPAL_NO_NAME_TYPE;
flags |= KRB5_STORAGE_HOST_BYTEORDER;
break;
case KRB5_FCC_FVNO_2:
flags |= KRB5_STORAGE_HOST_BYTEORDER;
break;
case KRB5_FCC_FVNO_3:
flags |= KRB5_STORAGE_KEYBLOCK_KEYTYPE_TWICE;
break;
case KRB5_FCC_FVNO_4:
break;
default:
krb5_abortx(context,
"storage_set_flags called with bad vno (%x)", vno);
}
krb5_storage_set_flags(sp, flags);
}
static krb5_error_code
fcc_open(krb5_context context,
krb5_ccache id,
int *fd_ret,
int flags,
mode_t mode)
{
krb5_boolean exclusive = ((flags | O_WRONLY) == flags ||
(flags | O_RDWR) == flags);
krb5_error_code ret;
const char *filename = FILENAME(id);
int fd;
fd = open(filename, flags, mode);
if(fd < 0) {
ret = errno;
krb5_set_error_string(context, "open(%s): %s", filename,
strerror(ret));
return ret;
}
if((ret = fcc_lock(context, id, fd, exclusive)) != 0) {
close(fd);
return ret;
}
*fd_ret = fd;
return 0;
}
static krb5_error_code
fcc_initialize(krb5_context context,
krb5_ccache id,
krb5_principal primary_principal)
{
krb5_fcache *f = FCACHE(id);
int ret = 0;
int fd;
char *filename = f->filename;
unlink (filename);
ret = fcc_open(context, id, &fd, O_RDWR | O_CREAT | O_EXCL | O_BINARY, 0600);
if(ret)
return ret;
{
krb5_storage *sp;
sp = krb5_storage_from_fd(fd);
krb5_storage_set_eof_code(sp, KRB5_CC_END);
if(context->fcache_vno != 0)
f->version = context->fcache_vno;
else
f->version = KRB5_FCC_FVNO_4;
ret |= krb5_store_int8(sp, 5);
ret |= krb5_store_int8(sp, f->version);
storage_set_flags(context, sp, f->version);
if(f->version == KRB5_FCC_FVNO_4 && ret == 0) {
/* V4 stuff */
if (context->kdc_sec_offset) {
ret |= krb5_store_int16 (sp, 12); /* length */
ret |= krb5_store_int16 (sp, FCC_TAG_DELTATIME); /* Tag */
ret |= krb5_store_int16 (sp, 8); /* length of data */
ret |= krb5_store_int32 (sp, context->kdc_sec_offset);
ret |= krb5_store_int32 (sp, context->kdc_usec_offset);
} else {
ret |= krb5_store_int16 (sp, 0);
}
}
ret |= krb5_store_principal(sp, primary_principal);
krb5_storage_free(sp);
}
fcc_unlock(context, fd);
if (close(fd) < 0)
if (ret == 0) {
ret = errno;
krb5_set_error_string (context, "close %s: %s",
FILENAME(id), strerror(ret));
}
return ret;
}
static krb5_error_code
fcc_close(krb5_context context,
krb5_ccache id)
{
free (FILENAME(id));
krb5_data_free(&id->data);
return 0;
}
static krb5_error_code
fcc_destroy(krb5_context context,
krb5_ccache id)
{
erase_file(FILENAME(id));
return 0;
}
static krb5_error_code
fcc_store_cred(krb5_context context,
krb5_ccache id,
krb5_creds *creds)
{
int ret;
int fd;
ret = fcc_open(context, id, &fd, O_WRONLY | O_APPEND | O_BINARY, 0);
if(ret)
return ret;
{
krb5_storage *sp;
sp = krb5_storage_from_fd(fd);
krb5_storage_set_eof_code(sp, KRB5_CC_END);
storage_set_flags(context, sp, FCACHE(id)->version);
if (!krb5_config_get_bool_default(context, NULL, TRUE,
"libdefaults",
"fcc-mit-ticketflags",
NULL))
krb5_storage_set_flags(sp, KRB5_STORAGE_CREDS_FLAGS_WRONG_BITORDER);
ret = krb5_store_creds(sp, creds);
krb5_storage_free(sp);
}
fcc_unlock(context, fd);
if (close(fd) < 0)
if (ret == 0) {
ret = errno;
krb5_set_error_string (context, "close %s: %s",
FILENAME(id), strerror(ret));
}
return ret;
}
static krb5_error_code
init_fcc (krb5_context context,
krb5_ccache id,
krb5_storage **ret_sp,
int *ret_fd)
{
int fd;
int8_t pvno, tag;
krb5_storage *sp;
krb5_error_code ret;
ret = fcc_open(context, id, &fd, O_RDONLY | O_BINARY, 0);
if(ret)
return ret;
sp = krb5_storage_from_fd(fd);
if(sp == NULL) {
krb5_clear_error_string(context);
ret = ENOMEM;
goto out;
}
krb5_storage_set_eof_code(sp, KRB5_CC_END);
ret = krb5_ret_int8(sp, &pvno);
if(ret != 0) {
if(ret == KRB5_CC_END)
ret = ENOENT; /* empty file */
krb5_clear_error_string(context);
goto out;
}
if(pvno != 5) {
krb5_set_error_string(context, "Bad version number in credential "
"cache file: %s", FILENAME(id));
ret = KRB5_CCACHE_BADVNO;
goto out;
}
ret = krb5_ret_int8(sp, &tag); /* should not be host byte order */
if(ret != 0) {
krb5_clear_error_string(context);
ret = KRB5_CC_FORMAT;
goto out;
}
FCACHE(id)->version = tag;
storage_set_flags(context, sp, FCACHE(id)->version);
switch (tag) {
case KRB5_FCC_FVNO_4: {
int16_t length;
ret = krb5_ret_int16 (sp, &length);
if(ret) {
ret = KRB5_CC_FORMAT;
krb5_clear_error_string(context);
goto out;
}
while(length > 0) {
int16_t tag, data_len;
int i;
int8_t dummy;
ret = krb5_ret_int16 (sp, &tag);
if(ret) {
krb5_clear_error_string(context);
ret = KRB5_CC_FORMAT;
goto out;
}
ret = krb5_ret_int16 (sp, &data_len);
if(ret) {
krb5_clear_error_string(context);
ret = KRB5_CC_FORMAT;
goto out;
}
switch (tag) {
case FCC_TAG_DELTATIME :
ret = krb5_ret_int32 (sp, &context->kdc_sec_offset);
if(ret) {
krb5_clear_error_string(context);
ret = KRB5_CC_FORMAT;
goto out;
}
ret = krb5_ret_int32 (sp, &context->kdc_usec_offset);
if(ret) {
krb5_clear_error_string(context);
ret = KRB5_CC_FORMAT;
goto out;
}
break;
default :
for (i = 0; i < data_len; ++i) {
ret = krb5_ret_int8 (sp, &dummy);
if(ret) {
krb5_clear_error_string(context);
ret = KRB5_CC_FORMAT;
goto out;
}
}
break;
}
length -= 4 + data_len;
}
break;
}
case KRB5_FCC_FVNO_3:
case KRB5_FCC_FVNO_2:
case KRB5_FCC_FVNO_1:
break;
default :
ret = KRB5_CCACHE_BADVNO;
krb5_set_error_string(context, "Unknown version number (%d) in "
"credential cache file: %s",
(int)tag, FILENAME(id));
goto out;
}
*ret_sp = sp;
*ret_fd = fd;
return 0;
out:
if(sp != NULL)
krb5_storage_free(sp);
fcc_unlock(context, fd);
close(fd);
return ret;
}
static krb5_error_code
fcc_get_principal(krb5_context context,
krb5_ccache id,
krb5_principal *principal)
{
krb5_error_code ret;
int fd;
krb5_storage *sp;
ret = init_fcc (context, id, &sp, &fd);
if (ret)
return ret;
ret = krb5_ret_principal(sp, principal);
if (ret)
krb5_clear_error_string(context);
krb5_storage_free(sp);
fcc_unlock(context, fd);
close(fd);
return ret;
}
static krb5_error_code
fcc_end_get (krb5_context context,
krb5_ccache id,
krb5_cc_cursor *cursor);
static krb5_error_code
fcc_get_first (krb5_context context,
krb5_ccache id,
krb5_cc_cursor *cursor)
{
krb5_error_code ret;
krb5_principal principal;
*cursor = malloc(sizeof(struct fcc_cursor));
if (*cursor == NULL) {
krb5_set_error_string (context, "malloc: out of memory");
return ENOMEM;
}
memset(*cursor, 0, sizeof(struct fcc_cursor));
ret = init_fcc (context, id, &FCC_CURSOR(*cursor)->sp,
&FCC_CURSOR(*cursor)->fd);
if (ret) {
free(*cursor);
*cursor = NULL;
return ret;
}
ret = krb5_ret_principal (FCC_CURSOR(*cursor)->sp, &principal);
if(ret) {
krb5_clear_error_string(context);
fcc_end_get(context, id, cursor);
return ret;
}
krb5_free_principal (context, principal);
fcc_unlock(context, FCC_CURSOR(*cursor)->fd);
return 0;
}
static krb5_error_code
fcc_get_next (krb5_context context,
krb5_ccache id,
krb5_cc_cursor *cursor,
krb5_creds *creds)
{
krb5_error_code ret;
if((ret = fcc_lock(context, id, FCC_CURSOR(*cursor)->fd, FALSE)) != 0)
return ret;
ret = krb5_ret_creds(FCC_CURSOR(*cursor)->sp, creds);
if (ret)
krb5_clear_error_string(context);
fcc_unlock(context, FCC_CURSOR(*cursor)->fd);
return ret;
}
static krb5_error_code
fcc_end_get (krb5_context context,
krb5_ccache id,
krb5_cc_cursor *cursor)
{
krb5_storage_free(FCC_CURSOR(*cursor)->sp);
close (FCC_CURSOR(*cursor)->fd);
free(*cursor);
*cursor = NULL;
return 0;
}
static krb5_error_code
fcc_remove_cred(krb5_context context,
krb5_ccache id,
krb5_flags which,
krb5_creds *cred)
{
krb5_error_code ret;
krb5_ccache copy;
ret = krb5_cc_gen_new(context, &krb5_mcc_ops, ©);
if (ret)
return ret;
ret = krb5_cc_copy_cache(context, id, copy);
if (ret) {
krb5_cc_destroy(context, copy);
return ret;
}
ret = krb5_cc_remove_cred(context, copy, which, cred);
if (ret) {
krb5_cc_destroy(context, copy);
return ret;
}
fcc_destroy(context, id);
ret = krb5_cc_copy_cache(context, copy, id);
krb5_cc_destroy(context, copy);
return ret;
}
static krb5_error_code
fcc_set_flags(krb5_context context,
krb5_ccache id,
krb5_flags flags)
{
return 0; /* XXX */
}
static krb5_error_code
fcc_get_version(krb5_context context,
krb5_ccache id)
{
return FCACHE(id)->version;
}
const krb5_cc_ops krb5_fcc_ops = {
"FILE",
fcc_get_name,
fcc_resolve,
fcc_gen_new,
fcc_initialize,
fcc_destroy,
fcc_close,
fcc_store_cred,
NULL, /* fcc_retrieve */
fcc_get_principal,
fcc_get_first,
fcc_get_next,
fcc_end_get,
fcc_remove_cred,
fcc_set_flags,
fcc_get_version
};