/* $NetBSD: expand_path.c,v 1.2 2017/01/28 21:31:49 christos Exp $ */
/***********************************************************************
* Copyright (c) 2009, Secure Endpoints Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - 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.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
* COPYRIGHT HOLDER 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"
#include <stdarg.h>
typedef int PTYPE;
#ifdef _WIN32
#include <shlobj.h>
#include <sddl.h>
/*
* Expand a %{TEMP} token
*
* The %{TEMP} token expands to the temporary path for the current
* user as returned by GetTempPath().
*
* @note: Since the GetTempPath() function relies on the TMP or TEMP
* environment variables, this function will failover to the system
* temporary directory until the user profile is loaded. In addition,
* the returned path may or may not exist.
*/
static krb5_error_code
_expand_temp_folder(krb5_context context, PTYPE param, const char *postfix, char **ret)
{
TCHAR tpath[MAX_PATH];
size_t len;
if (!GetTempPath(sizeof(tpath)/sizeof(tpath[0]), tpath)) {
if (context)
krb5_set_error_message(context, EINVAL,
"Failed to get temporary path (GLE=%d)",
GetLastError());
return EINVAL;
}
len = strlen(tpath);
if (len > 0 && tpath[len - 1] == '\\')
tpath[len - 1] = '\0';
*ret = strdup(tpath);
if (*ret == NULL)
return krb5_enomem(context);
return 0;
}
extern HINSTANCE _krb5_hInstance;
/*
* Expand a %{BINDIR} token
*
* This is also used to expand a few other tokens on Windows, since
* most of the executable binaries end up in the same directory. The
* "bin" directory is considered to be the directory in which the
* krb5.dll is located.
*/
static krb5_error_code
_expand_bin_dir(krb5_context context, PTYPE param, const char *postfix, char **ret)
{
TCHAR path[MAX_PATH];
TCHAR *lastSlash;
DWORD nc;
nc = GetModuleFileName(_krb5_hInstance, path, sizeof(path)/sizeof(path[0]));
if (nc == 0 ||
nc == sizeof(path)/sizeof(path[0])) {
return EINVAL;
}
lastSlash = strrchr(path, '\\');
if (lastSlash != NULL) {
TCHAR *fslash = strrchr(lastSlash, '/');
if (fslash != NULL)
lastSlash = fslash;
*lastSlash = '\0';
}
if (postfix) {
if (strlcat(path, postfix, sizeof(path)/sizeof(path[0])) >= sizeof(path)/sizeof(path[0]))
return EINVAL;
}
*ret = strdup(path);
if (*ret == NULL)
return krb5_enomem(context);
return 0;
}
/*
* Expand a %{USERID} token
*
* The %{USERID} token expands to the string representation of the
* user's SID. The user account that will be used is the account
* corresponding to the current thread's security token. This means
* that:
*
* - If the current thread token has the anonymous impersonation
* level, the call will fail.
*
* - If the current thread is impersonating a token at
* SecurityIdentification level the call will fail.
*
*/
static krb5_error_code
_expand_userid(krb5_context context, PTYPE param, const char *postfix, char **ret)
{
int rv = EINVAL;
HANDLE hThread = NULL;
HANDLE hToken = NULL;
PTOKEN_OWNER pOwner = NULL;
DWORD len = 0;
LPTSTR strSid = NULL;
hThread = GetCurrentThread();
if (!OpenThreadToken(hThread, TOKEN_QUERY,
FALSE, /* Open the thread token as the
current thread user. */
&hToken)) {
DWORD le = GetLastError();
if (le == ERROR_NO_TOKEN) {
HANDLE hProcess = GetCurrentProcess();
le = 0;
if (!OpenProcessToken(hProcess, TOKEN_QUERY, &hToken))
le = GetLastError();
}
if (le != 0) {
if (context)
krb5_set_error_message(context, rv,
"Can't open thread token (GLE=%d)", le);
goto _exit;
}
}
if (!GetTokenInformation(hToken, TokenOwner, NULL, 0, &len)) {
if (GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
if (context)
krb5_set_error_message(context, rv,
"Unexpected error reading token information (GLE=%d)",
GetLastError());
goto _exit;
}
if (len == 0) {
if (context)
krb5_set_error_message(context, rv,
"GetTokenInformation() returned truncated buffer");
goto _exit;
}
pOwner = malloc(len);
if (pOwner == NULL) {
if (context)
krb5_set_error_message(context, rv, "Out of memory");
goto _exit;
}
} else {
if (context)
krb5_set_error_message(context, rv, "GetTokenInformation() returned truncated buffer");
goto _exit;
}
if (!GetTokenInformation(hToken, TokenOwner, pOwner, len, &len)) {
if (context)
krb5_set_error_message(context, rv, "GetTokenInformation() failed. GLE=%d", GetLastError());
goto _exit;
}
if (!ConvertSidToStringSid(pOwner->Owner, &strSid)) {
if (context)
krb5_set_error_message(context, rv, "Can't convert SID to string. GLE=%d", GetLastError());
goto _exit;
}
*ret = strdup(strSid);
if (*ret == NULL && context)
krb5_set_error_message(context, rv, "Out of memory");
rv = 0;
_exit:
if (hToken != NULL)
CloseHandle(hToken);
if (pOwner != NULL)
free (pOwner);
if (strSid != NULL)
LocalFree(strSid);
return rv;
}
/*
* Expand a folder identified by a CSIDL
*/
static krb5_error_code
_expand_csidl(krb5_context context, PTYPE folder, const char *postfix, char **ret)
{
TCHAR path[MAX_PATH];
size_t len;
if (SHGetFolderPath(NULL, folder, NULL, SHGFP_TYPE_CURRENT, path) != S_OK) {
if (context)
krb5_set_error_message(context, EINVAL, "Unable to determine folder path");
return EINVAL;
}
len = strlen(path);
if (len > 0 && path[len - 1] == '\\')
path[len - 1] = '\0';
if (postfix &&
strlcat(path, postfix, sizeof(path)/sizeof(path[0])) >= sizeof(path)/sizeof(path[0]))
return krb5_enomem(context);
*ret = strdup(path);
if (*ret == NULL)
return krb5_enomem(context);
return 0;
}
#else
static krb5_error_code
_expand_path(krb5_context context, PTYPE param, const char *postfix, char **ret)
{
*ret = strdup(postfix);
if (*ret == NULL)
return krb5_enomem(context);
return 0;
}
static krb5_error_code
_expand_temp_folder(krb5_context context, PTYPE param, const char *postfix, char **ret)
{
const char *p = NULL;
if (!issuid())
p = getenv("TEMP");
if (p)
*ret = strdup(p);
else
*ret = strdup("/tmp");
if (*ret == NULL)
return krb5_enomem(context);
return 0;
}
static krb5_error_code
_expand_userid(krb5_context context, PTYPE param, const char *postfix, char **str)
{
int ret = asprintf(str, "%ld", (unsigned long)getuid());
if (ret < 0 || *str == NULL)
return krb5_enomem(context);
return 0;
}
#endif /* _WIN32 */
/**
* Expand an extra token
*/
static krb5_error_code
_expand_extra_token(krb5_context context, const char *value, char **ret)
{
*ret = strdup(value);
if (*ret == NULL)
return krb5_enomem(context);
return 0;
}
/**
* Expand a %{null} token
*
* The expansion of a %{null} token is always the empty string.
*/
static krb5_error_code
_expand_null(krb5_context context, PTYPE param, const char *postfix, char **ret)
{
*ret = strdup("");
if (*ret == NULL)
return krb5_enomem(context);
return 0;
}
static const struct {
const char * tok;
int ftype;
#define FTYPE_CSIDL 0
#define FTYPE_SPECIAL 1
PTYPE param;
const char * postfix;
int (*exp_func)(krb5_context, PTYPE, const char *, char **);
#define SPECIALP(f, P) FTYPE_SPECIAL, 0, P, f
#define SPECIAL(f) SPECIALP(f, NULL)
} tokens[] = {
#ifdef _WIN32
#define CSIDLP(C,P) FTYPE_CSIDL, C, P, _expand_csidl
#define CSIDL(C) CSIDLP(C, NULL)
{"APPDATA", CSIDL(CSIDL_APPDATA)}, /* Roaming application data (for current user) */
{"COMMON_APPDATA", CSIDL(CSIDL_COMMON_APPDATA)}, /* Application data (all users) */
{"LOCAL_APPDATA", CSIDL(CSIDL_LOCAL_APPDATA)}, /* Local application data (for current user) */
{"SYSTEM", CSIDL(CSIDL_SYSTEM)}, /* Windows System folder (e.g. %WINDIR%\System32) */
{"WINDOWS", CSIDL(CSIDL_WINDOWS)}, /* Windows folder */
{"USERCONFIG", CSIDLP(CSIDL_APPDATA, "\\" PACKAGE)}, /* Per user Heimdal configuration file path */
{"COMMONCONFIG", CSIDLP(CSIDL_COMMON_APPDATA, "\\" PACKAGE)}, /* Common Heimdal configuration file path */
{"LIBDIR", SPECIAL(_expand_bin_dir)},
{"BINDIR", SPECIAL(_expand_bin_dir)},
{"LIBEXEC", SPECIAL(_expand_bin_dir)},
{"SBINDIR", SPECIAL(_expand_bin_dir)},
#else
{"LIBDIR", FTYPE_SPECIAL, 0, LIBDIR, _expand_path},
{"BINDIR", FTYPE_SPECIAL, 0, BINDIR, _expand_path},
{"LIBEXEC", FTYPE_SPECIAL, 0, LIBEXECDIR, _expand_path},
{"SBINDIR", FTYPE_SPECIAL, 0, SBINDIR, _expand_path},
#endif
{"TEMP", SPECIAL(_expand_temp_folder)},
{"USERID", SPECIAL(_expand_userid)},
{"uid", SPECIAL(_expand_userid)},
{"null", SPECIAL(_expand_null)}
};
static krb5_error_code
_expand_token(krb5_context context,
const char *token,
const char *token_end,
char **extra_tokens,
char **ret)
{
size_t i;
char **p;
*ret = NULL;
if (token[0] != '%' || token[1] != '{' || token_end[0] != '}' ||
token_end - token <= 2) {
if (context)
krb5_set_error_message(context, EINVAL,"Invalid token.");
return EINVAL;
}
for (p = extra_tokens; p && p[0]; p += 2) {
if (strncmp(token+2, p[0], (token_end - token) - 2) == 0)
return _expand_extra_token(context, p[1], ret);
}
for (i = 0; i < sizeof(tokens)/sizeof(tokens[0]); i++) {
if (!strncmp(token+2, tokens[i].tok, (token_end - token) - 2))
return tokens[i].exp_func(context, tokens[i].param,
tokens[i].postfix, ret);
}
if (context)
krb5_set_error_message(context, EINVAL, "Invalid token.");
return EINVAL;
}
/**
* Internal function to expand tokens in paths.
*
* Inputs:
*
* @context A krb5_context
* @path_in The path to expand tokens from
*
* Outputs:
*
* @ppath_out Path with expanded tokens (caller must free() this)
*/
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
_krb5_expand_path_tokens(krb5_context context,
const char *path_in,
int filepath,
char **ppath_out)
{
return _krb5_expand_path_tokensv(context, path_in, filepath, ppath_out, NULL);
}
static void
free_extra_tokens(char **extra_tokens)
{
char **p;
for (p = extra_tokens; p && *p; p++)
free(*p);
free(extra_tokens);
}
/**
* Internal function to expand tokens in paths.
*
* Inputs:
*
* @context A krb5_context
* @path_in The path to expand tokens from
* @ppath_out The expanded path
* @... Variable number of pairs of strings, the first of each
* being a token (e.g., "luser") and the second a string to
* replace it with. The list is terminated by a NULL.
*
* Outputs:
*
* @ppath_out Path with expanded tokens (caller must free() this)
*/
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
_krb5_expand_path_tokensv(krb5_context context,
const char *path_in,
int filepath,
char **ppath_out, ...)
{
char *tok_begin, *tok_end, *append;
char **extra_tokens = NULL;
const char *path_left;
size_t nargs = 0;
size_t len = 0;
va_list ap;
if (path_in == NULL || *path_in == '\0') {
*ppath_out = strdup("");
return 0;
}
*ppath_out = NULL;
va_start(ap, ppath_out);
while (va_arg(ap, const char *)) {
nargs++;
va_arg(ap, const char *);
}
va_end(ap);
nargs *= 2;
/* Get extra tokens */
if (nargs) {
size_t i;
extra_tokens = calloc(nargs + 1, sizeof (*extra_tokens));
if (extra_tokens == NULL)
return krb5_enomem(context);
va_start(ap, ppath_out);
for (i = 0; i < nargs; i++) {
const char *s = va_arg(ap, const char *); /* token key */
if (s == NULL)
break;
extra_tokens[i] = strdup(s);
if (extra_tokens[i++] == NULL) {
va_end(ap);
free_extra_tokens(extra_tokens);
return krb5_enomem(context);
}
s = va_arg(ap, const char *); /* token value */
if (s == NULL)
s = "";
extra_tokens[i] = strdup(s);
if (extra_tokens[i] == NULL) {
va_end(ap);
free_extra_tokens(extra_tokens);
return krb5_enomem(context);
}
}
va_end(ap);
}
for (path_left = path_in; path_left && *path_left; ) {
tok_begin = strstr(path_left, "%{");
if (tok_begin && tok_begin != path_left) {
append = malloc((tok_begin - path_left) + 1);
if (append) {
memcpy(append, path_left, tok_begin - path_left);
append[tok_begin - path_left] = '\0';
}
path_left = tok_begin;
} else if (tok_begin) {
tok_end = strchr(tok_begin, '}');
if (tok_end == NULL) {
free_extra_tokens(extra_tokens);
if (*ppath_out)
free(*ppath_out);
*ppath_out = NULL;
if (context)
krb5_set_error_message(context, EINVAL, "variable missing }");
return EINVAL;
}
if (_expand_token(context, tok_begin, tok_end, extra_tokens,
&append)) {
free_extra_tokens(extra_tokens);
if (*ppath_out)
free(*ppath_out);
*ppath_out = NULL;
return EINVAL;
}
path_left = tok_end + 1;
} else {
append = strdup(path_left);
path_left = NULL;
}
if (append == NULL) {
free_extra_tokens(extra_tokens);
if (*ppath_out)
free(*ppath_out);
*ppath_out = NULL;
return krb5_enomem(context);
}
{
size_t append_len = strlen(append);
char * new_str = realloc(*ppath_out, len + append_len + 1);
if (new_str == NULL) {
free_extra_tokens(extra_tokens);
free(append);
if (*ppath_out)
free(*ppath_out);
*ppath_out = NULL;
return krb5_enomem(context);
}
*ppath_out = new_str;
memcpy(*ppath_out + len, append, append_len + 1);
len = len + append_len;
free(append);
}
}
#ifdef _WIN32
/* Also deal with slashes */
if (filepath && *ppath_out) {
char * c;
for (c = *ppath_out; *c; c++)
if (*c == '/')
*c = '\\';
}
#endif
free_extra_tokens(extra_tokens);
return 0;
}