/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* lib/krb5/keytab/kt_memory.c */
/*
* Copyright 2007 by Secure Endpoints Inc.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation files
* (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge,
* publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include "k5-int.h"
#include "kt-int.h"
#include <stdio.h>
#ifndef LEAN_CLIENT
#define HEIMDAL_COMPATIBLE
/*
* Information needed by internal routines of the file-based ticket
* cache implementation.
*/
/*
* Constants
*/
/*
* Types
*/
/* From krb5.h:
* typedef struct krb5_keytab_entry_st {
* krb5_magic magic;
* krb5_principal principal; principal of this key
* krb5_timestamp timestamp; time entry written to keytable
* krb5_kvno vno; key version number
* krb5_keyblock key; the secret key
*} krb5_keytab_entry;
*/
/* Individual key entries within a table, in a linked list */
typedef struct _krb5_mkt_link {
struct _krb5_mkt_link *next;
krb5_keytab_entry *entry;
} krb5_mkt_link, *krb5_mkt_cursor;
/* Per-keytab data header */
typedef struct _krb5_mkt_data {
char *name; /* Name of the keytab */
k5_mutex_t lock; /* Thread-safety - all but link */
krb5_int32 refcount;
krb5_mkt_cursor link;
} krb5_mkt_data;
/* List of memory key tables */
typedef struct _krb5_mkt_list_node {
struct _krb5_mkt_list_node *next;
krb5_keytab keytab;
} krb5_mkt_list_node;
/* Iterator over memory key tables */
typedef struct _krb5_mkt_ptcursor_data {
struct _krb5_mkt_list_node *cur;
} krb5_mkt_ptcursor_data;
/*
* Globals
*/
static krb5_mkt_list_node * krb5int_mkt_list = NULL;
static k5_mutex_t krb5int_mkt_mutex = K5_MUTEX_PARTIAL_INITIALIZER;
/*
* Macros
*/
#define KTLOCK(id) k5_mutex_lock(&(((krb5_mkt_data *)(id)->data)->lock))
#define KTUNLOCK(id) k5_mutex_unlock(&(((krb5_mkt_data *)(id)->data)->lock))
#define KTCHECKLOCK(id) k5_mutex_assert_locked(&(((krb5_mkt_data *)(id)->data)->lock))
#define KTGLOCK k5_mutex_lock(&krb5int_mkt_mutex)
#define KTGUNLOCK k5_mutex_unlock(&krb5int_mkt_mutex)
#define KTGCHECKLOCK k5_mutex_assert_locked(&krb5int_mkt_mutex)
#define KTLINK(id) (((krb5_mkt_data *)(id)->data)->link)
#define KTREFCNT(id) (((krb5_mkt_data *)(id)->data)->refcount)
#define KTNAME(id) (((krb5_mkt_data *)(id)->data)->name)
extern const struct _krb5_kt_ops krb5_mkt_ops;
krb5_error_code KRB5_CALLCONV
krb5_mkt_resolve(krb5_context, const char *, krb5_keytab *);
krb5_error_code KRB5_CALLCONV
krb5_mkt_get_name(krb5_context, krb5_keytab, char *, unsigned int);
krb5_error_code KRB5_CALLCONV
krb5_mkt_close(krb5_context, krb5_keytab);
krb5_error_code KRB5_CALLCONV
krb5_mkt_get_entry(krb5_context, krb5_keytab, krb5_const_principal, krb5_kvno,
krb5_enctype, krb5_keytab_entry *);
krb5_error_code KRB5_CALLCONV
krb5_mkt_start_seq_get(krb5_context, krb5_keytab, krb5_kt_cursor *);
krb5_error_code KRB5_CALLCONV
krb5_mkt_get_next(krb5_context, krb5_keytab, krb5_keytab_entry *,
krb5_kt_cursor *);
krb5_error_code KRB5_CALLCONV
krb5_mkt_end_get(krb5_context, krb5_keytab, krb5_kt_cursor *);
/* routines to be included on extended version (write routines) */
krb5_error_code KRB5_CALLCONV
krb5_mkt_add(krb5_context, krb5_keytab, krb5_keytab_entry *);
krb5_error_code KRB5_CALLCONV
krb5_mkt_remove(krb5_context, krb5_keytab, krb5_keytab_entry *);
int
krb5int_mkt_initialize(void)
{
return k5_mutex_finish_init(&krb5int_mkt_mutex);
}
void
krb5int_mkt_finalize(void)
{
krb5_mkt_list_node *node, *next_node;
krb5_mkt_cursor cursor, next_cursor;
k5_mutex_destroy(&krb5int_mkt_mutex);
for (node = krb5int_mkt_list; node; node = next_node) {
next_node = node->next;
/* destroy the contents of node->keytab */
free(KTNAME(node->keytab));
/* free the keytab entries */
for (cursor = KTLINK(node->keytab); cursor; cursor = next_cursor) {
next_cursor = cursor->next;
/* the call to krb5_kt_free_entry uses a NULL in place of the
* krb5_context since we know that the context isn't used by
* krb5_kt_free_entry or krb5_free_principal. */
krb5_kt_free_entry(NULL, cursor->entry);
free(cursor->entry);
free(cursor);
}
/* destroy the lock */
k5_mutex_destroy(&(((krb5_mkt_data *)node->keytab->data)->lock));
/* free the private data */
free(node->keytab->data);
/* and the keytab */
free(node->keytab);
/* and finally the node */
free(node);
}
}
static krb5_error_code
create_list_node(const char *name, krb5_mkt_list_node **listp)
{
krb5_mkt_list_node *list;
krb5_mkt_data *data = NULL;
krb5_error_code err;
*listp = NULL;
list = calloc(1, sizeof(krb5_mkt_list_node));
if (list == NULL) {
err = ENOMEM;
goto cleanup;
}
list->keytab = calloc(1, sizeof(struct _krb5_kt));
if (list->keytab == NULL) {
err = ENOMEM;
goto cleanup;
}
list->keytab->ops = &krb5_mkt_ops;
data = calloc(1, sizeof(krb5_mkt_data));
if (data == NULL) {
err = ENOMEM;
goto cleanup;
}
data->link = NULL;
data->refcount = 0;
data->name = strdup(name);
if (data->name == NULL) {
err = ENOMEM;
goto cleanup;
}
err = k5_mutex_init(&data->lock);
if (err)
goto cleanup;
list->keytab->data = data;
list->keytab->magic = KV5M_KEYTAB;
list->next = NULL;
*listp = list;
return 0;
cleanup:
/* data->lock was initialized last, so no need to destroy. */
if (data)
free(data->name);
free(data);
if (list)
free(list->keytab);
free(list);
return err;
}
/*
* This is an implementation specific resolver. It returns a keytab
* initialized with memory keytab routines.
*/
krb5_error_code KRB5_CALLCONV
krb5_mkt_resolve(krb5_context context, const char *name, krb5_keytab *id)
{
krb5_mkt_list_node *list;
krb5_error_code err = 0;
*id = NULL;
/* First determine if a memory keytab of this name already exists */
KTGLOCK;
for (list = krb5int_mkt_list; list; list = list->next) {
if (strcmp(name,KTNAME(list->keytab)) == 0)
break;
}
if (!list) {
/* We will now create the new key table with the specified name.
* We do not drop the global lock, therefore the name will indeed
* be unique when we add it.
*/
err = create_list_node(name, &list);
if (err)
goto done;
list->next = krb5int_mkt_list;
krb5int_mkt_list = list;
}
/* Increment the reference count on the keytab we found or created. */
KTLOCK(list->keytab);
KTREFCNT(list->keytab)++;
KTUNLOCK(list->keytab);
*id = list->keytab;
done:
KTGUNLOCK;
return err;
}
/*
* "Close" a memory-based keytab. This is effectively a no-op.
* We check to see if the keytab exists and that is about it.
* Closing a file keytab does not destroy the contents. Closing
* a memory keytab shouldn't either.
*/
krb5_error_code KRB5_CALLCONV
krb5_mkt_close(krb5_context context, krb5_keytab id)
{
krb5_mkt_list_node **listp;
#ifdef HEIMDAL_COMPATIBLE
krb5_mkt_list_node *node;
krb5_mkt_data * data;
#endif
krb5_error_code err = 0;
/* First determine if a memory keytab of this name already exists */
KTGLOCK;
for (listp = &krb5int_mkt_list; *listp; listp = &((*listp)->next))
{
if (id == (*listp)->keytab) {
/* Found */
break;
}
}
if (*listp == NULL) {
/* The specified keytab could not be found */
err = KRB5_KT_NOTFOUND;
goto done;
}
/* reduce the refcount and return */
KTLOCK(id);
KTREFCNT(id)--;
KTUNLOCK(id);
#ifdef HEIMDAL_COMPATIBLE
/* In Heimdal if the refcount hits 0, the MEMORY keytab is
* destroyed since there is no krb5_kt_destroy function.
* There is no need to lock the entry while performing
* these operations as the refcount will be 0 and we are
* holding the global lock.
*/
data = (krb5_mkt_data *)id->data;
if (data->refcount == 0) {
krb5_mkt_cursor cursor, next_cursor;
node = *listp;
*listp = node->next;
/* destroy the contents of node->keytab (aka id) */
free(data->name);
/* free the keytab entries */
for (cursor = KTLINK(node->keytab); cursor; cursor = next_cursor) {
next_cursor = cursor->next;
krb5_kt_free_entry(context, cursor->entry);
free(cursor->entry);
free(cursor);
}
/* destroy the lock */
k5_mutex_destroy(&(data->lock));
/* free the private data */
free(data);
/* and the keytab */
free(node->keytab);
/* and finally the node */
free(node);
}
#endif /* HEIMDAL_COMPATIBLE */
done:
KTGUNLOCK;
return(err);
}
/*
* This is the get_entry routine for the memory based keytab implementation.
* It either retrieves the entry or returns an error.
*/
krb5_error_code KRB5_CALLCONV
krb5_mkt_get_entry(krb5_context context, krb5_keytab id,
krb5_const_principal principal, krb5_kvno kvno,
krb5_enctype enctype, krb5_keytab_entry *out_entry)
{
krb5_mkt_cursor cursor;
krb5_keytab_entry *entry, *match = NULL;
krb5_error_code err = 0;
int found_wrong_kvno = 0;
krb5_boolean similar = 0;
KTLOCK(id);
for (cursor = KTLINK(id); cursor && cursor->entry; cursor = cursor->next) {
entry = cursor->entry;
/* if the principal isn't the one requested, continue to the next. */
if (!krb5_principal_compare(context, principal, entry->principal))
continue;
/* if the enctype is not ignored and doesn't match,
and continue to the next */
if (enctype != IGNORE_ENCTYPE) {
if ((err = krb5_c_enctype_compare(context, enctype,
entry->key.enctype,
&similar))) {
/* we can't determine the enctype of the entry */
continue;
}
if (!similar)
continue;
}
if (kvno == IGNORE_VNO || entry->vno == IGNORE_VNO) {
if (match == NULL)
match = entry;
else if (entry->vno > match->vno)
match = entry;
} else {
if (entry->vno == kvno) {
match = entry;
break;
} else {
found_wrong_kvno++;
}
}
}
/* if we found an entry that matches, ... */
if (match) {
out_entry->magic = match->magic;
out_entry->timestamp = match->timestamp;
out_entry->vno = match->vno;
out_entry->key = match->key;
err = krb5_copy_keyblock_contents(context, &(match->key),
&(out_entry->key));
/*
* Coerce the enctype of the output keyblock in case we
* got an inexact match on the enctype.
*/
if(enctype != IGNORE_ENCTYPE)
out_entry->key.enctype = enctype;
if(!err) {
err = krb5_copy_principal(context,
match->principal,
&(out_entry->principal));
}
} else {
if (!err)
err = found_wrong_kvno ? KRB5_KT_KVNONOTFOUND : KRB5_KT_NOTFOUND;
}
KTUNLOCK(id);
return(err);
}
/*
* Get the name of the memory-based keytab.
*/
krb5_error_code KRB5_CALLCONV
krb5_mkt_get_name(krb5_context context, krb5_keytab id, char *name, unsigned int len)
{
int result;
memset(name, 0, len);
result = snprintf(name, len, "%s:%s", id->ops->prefix, KTNAME(id));
if (SNPRINTF_OVERFLOW(result, len))
return(KRB5_KT_NAME_TOOLONG);
return(0);
}
/*
* krb5_mkt_start_seq_get()
*/
krb5_error_code KRB5_CALLCONV
krb5_mkt_start_seq_get(krb5_context context, krb5_keytab id, krb5_kt_cursor *cursorp)
{
KTLOCK(id);
*cursorp = (krb5_kt_cursor)KTLINK(id);
KTUNLOCK(id);
return(0);
}
/*
* krb5_mkt_get_next()
*/
krb5_error_code KRB5_CALLCONV
krb5_mkt_get_next(krb5_context context, krb5_keytab id, krb5_keytab_entry *entry, krb5_kt_cursor *cursor)
{
krb5_mkt_cursor mkt_cursor = (krb5_mkt_cursor)*cursor;
krb5_error_code err = 0;
KTLOCK(id);
if (mkt_cursor == NULL) {
KTUNLOCK(id);
return KRB5_KT_END;
}
entry->magic = mkt_cursor->entry->magic;
entry->timestamp = mkt_cursor->entry->timestamp;
entry->vno = mkt_cursor->entry->vno;
entry->key = mkt_cursor->entry->key;
err = krb5_copy_keyblock_contents(context, &(mkt_cursor->entry->key),
&(entry->key));
if (!err)
err = krb5_copy_principal(context, mkt_cursor->entry->principal,
&(entry->principal));
if (!err)
*cursor = (krb5_kt_cursor *)mkt_cursor->next;
KTUNLOCK(id);
return(err);
}
/*
* krb5_mkt_end_get()
*/
krb5_error_code KRB5_CALLCONV
krb5_mkt_end_get(krb5_context context, krb5_keytab id, krb5_kt_cursor *cursor)
{
*cursor = NULL;
return(0);
}
/*
* krb5_mkt_add()
*/
krb5_error_code KRB5_CALLCONV
krb5_mkt_add(krb5_context context, krb5_keytab id, krb5_keytab_entry *entry)
{
krb5_error_code err = 0;
krb5_mkt_cursor cursor;
KTLOCK(id);
cursor = (krb5_mkt_cursor)malloc(sizeof(krb5_mkt_link));
if (cursor == NULL) {
err = ENOMEM;
goto done;
}
cursor->entry = (krb5_keytab_entry *)malloc(sizeof(krb5_keytab_entry));
if (cursor->entry == NULL) {
free(cursor);
err = ENOMEM;
goto done;
}
cursor->entry->magic = entry->magic;
cursor->entry->timestamp = entry->timestamp;
cursor->entry->vno = entry->vno;
err = krb5_copy_keyblock_contents(context, &(entry->key),
&(cursor->entry->key));
if (err) {
free(cursor->entry);
free(cursor);
goto done;
}
err = krb5_copy_principal(context, entry->principal, &(cursor->entry->principal));
if (err) {
krb5_free_keyblock_contents(context, &(cursor->entry->key));
free(cursor->entry);
free(cursor);
goto done;
}
if (KTLINK(id) == NULL) {
cursor->next = NULL;
KTLINK(id) = cursor;
} else {
cursor->next = KTLINK(id);
KTLINK(id) = cursor;
}
done:
KTUNLOCK(id);
return err;
}
/*
* krb5_mkt_remove()
*/
krb5_error_code KRB5_CALLCONV
krb5_mkt_remove(krb5_context context, krb5_keytab id, krb5_keytab_entry *entry)
{
krb5_mkt_cursor *pcursor, next;
krb5_error_code err = 0;
KTLOCK(id);
if ( KTLINK(id) == NULL ) {
err = KRB5_KT_NOTFOUND;
goto done;
}
for ( pcursor = &KTLINK(id); *pcursor; pcursor = &(*pcursor)->next ) {
if ( (*pcursor)->entry->vno == entry->vno &&
(*pcursor)->entry->key.enctype == entry->key.enctype &&
krb5_principal_compare(context, (*pcursor)->entry->principal, entry->principal))
break;
}
if (!*pcursor) {
err = KRB5_KT_NOTFOUND;
goto done;
}
krb5_kt_free_entry(context, (*pcursor)->entry);
free((*pcursor)->entry);
next = (*pcursor)->next;
free(*pcursor);
(*pcursor) = next;
done:
KTUNLOCK(id);
return err;
}
/*
* krb5_mkt_ops
*/
const struct _krb5_kt_ops krb5_mkt_ops = {
0,
"MEMORY", /* Prefix -- this string should not appear anywhere else! */
krb5_mkt_resolve,
krb5_mkt_get_name,
krb5_mkt_close,
krb5_mkt_get_entry,
krb5_mkt_start_seq_get,
krb5_mkt_get_next,
krb5_mkt_end_get,
krb5_mkt_add,
krb5_mkt_remove,
NULL
};
#endif /* LEAN_CLIENT */
