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gnupg/common/sysutils.c
Werner Koch 8ed85ef3de
agent: Keep some permissions of private-keys-v1.d. 
* common/sysutils.c (modestr_to_mode): Re-implement.
(gnupg_chmod): Support keeping of permissions.
--

GnuPG-bug-id: 2312
2020-09-09 20:34:59 +02:00

1458 lines
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/* sysutils.c - system helpers
* Copyright (C) 1991-2001, 2003-2004,
* 2006-2008 Free Software Foundation, Inc.
* Copyright (C) 2013-2016 Werner Koch
*
* This file is part of GnuPG.
*
* This file is free software; you can redistribute it and/or modify
* it under the terms of either
*
* - the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 3 of the License, or (at
* your option) any later version.
*
* or
*
* - the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* or both in parallel, as here.
*
* This file is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses/>.
*/
#include <config.h>
#ifdef WITHOUT_NPTH /* Give the Makefile a chance to build without Pth. */
# undef HAVE_NPTH
# undef USE_NPTH
#endif
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <limits.h>
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#ifdef HAVE_STAT
# include <sys/stat.h>
#endif
#if defined(__linux__) && defined(__alpha__) && __GLIBC__ < 2
# include <asm/sysinfo.h>
# include <asm/unistd.h>
#endif
#include <time.h>
#ifdef HAVE_SETRLIMIT
# include <sys/time.h>
# include <sys/resource.h>
#endif
#ifdef HAVE_PWD_H
# include <pwd.h>
# include <grp.h>
#endif /*HAVE_PWD_H*/
#ifdef HAVE_W32_SYSTEM
# if WINVER < 0x0500
# define WINVER 0x0500 /* Required for AllowSetForegroundWindow. */
# endif
# ifdef HAVE_WINSOCK2_H
# include <winsock2.h>
# endif
# include <windows.h>
#else /*!HAVE_W32_SYSTEM*/
# include <sys/socket.h>
# include <sys/un.h>
#endif
#ifdef HAVE_INOTIFY_INIT
# include <sys/inotify.h>
#endif /*HAVE_INOTIFY_INIT*/
#ifdef HAVE_NPTH
# include <npth.h>
#endif
#include <fcntl.h>
#include <assuan.h>
#include "util.h"
#include "i18n.h"
#include "sysutils.h"
#define tohex(n) ((n) < 10 ? ((n) + '0') : (((n) - 10) + 'A'))
/* Flag to tell whether special file names are enabled. See gpg.c for
* an explanation of these file names. */
static int allow_special_filenames;
#ifdef HAVE_W32_SYSTEM
/* State of gnupg_inhibit_set_foregound_window. */
static int inhibit_set_foregound_window;
#endif
static GPGRT_INLINE gpg_error_t
my_error_from_syserror (void)
{
return gpg_err_make (default_errsource, gpg_err_code_from_syserror ());
}
static GPGRT_INLINE gpg_error_t
my_error (int e)
{
return gpg_err_make (default_errsource, (e));
}
#if defined(__linux__) && defined(__alpha__) && __GLIBC__ < 2
#warning using trap_unaligned
static int
setsysinfo(unsigned long op, void *buffer, unsigned long size,
int *start, void *arg, unsigned long flag)
{
return syscall(__NR_osf_setsysinfo, op, buffer, size, start, arg, flag);
}
void
trap_unaligned(void)
{
unsigned int buf[2];
buf[0] = SSIN_UACPROC;
buf[1] = UAC_SIGBUS | UAC_NOPRINT;
setsysinfo(SSI_NVPAIRS, buf, 1, 0, 0, 0);
}
#else
void
trap_unaligned(void)
{ /* dummy */
}
#endif
int
disable_core_dumps (void)
{
#ifdef HAVE_DOSISH_SYSTEM
return 0;
#else
# ifdef HAVE_SETRLIMIT
struct rlimit limit;
/* We only set the current limit unless we were not able to
retrieve the old value. */
if (getrlimit (RLIMIT_CORE, &limit))
limit.rlim_max = 0;
limit.rlim_cur = 0;
if( !setrlimit (RLIMIT_CORE, &limit) )
return 0;
if( errno != EINVAL && errno != ENOSYS )
log_fatal (_("can't disable core dumps: %s\n"), strerror(errno) );
#endif
return 1;
#endif
}
int
enable_core_dumps (void)
{
#ifdef HAVE_DOSISH_SYSTEM
return 0;
#else
# ifdef HAVE_SETRLIMIT
struct rlimit limit;
if (getrlimit (RLIMIT_CORE, &limit))
return 1;
limit.rlim_cur = limit.rlim_max;
setrlimit (RLIMIT_CORE, &limit);
return 1; /* We always return true because this function is
merely a debugging aid. */
# endif
return 1;
#endif
}
/* Allow the use of special "-&nnn" style file names. */
void
enable_special_filenames (void)
{
allow_special_filenames = 1;
}
/* Return a string which is used as a kind of process ID. */
const byte *
get_session_marker (size_t *rlen)
{
static byte marker[SIZEOF_UNSIGNED_LONG*2];
static int initialized;
if (!initialized)
{
gcry_create_nonce (marker, sizeof marker);
initialized = 1;
}
*rlen = sizeof (marker);
return marker;
}
/* Return a random number in an unsigned int. */
unsigned int
get_uint_nonce (void)
{
unsigned int value;
gcry_create_nonce (&value, sizeof value);
return value;
}
#if 0 /* not yet needed - Note that this will require inclusion of
cmacros.am in Makefile.am */
int
check_permissions(const char *path,int extension,int checkonly)
{
#if defined(HAVE_STAT) && !defined(HAVE_DOSISH_SYSTEM)
char *tmppath;
struct stat statbuf;
int ret=1;
int isdir=0;
if(opt.no_perm_warn)
return 0;
if(extension && path[0]!=DIRSEP_C)
{
if(strchr(path,DIRSEP_C))
tmppath=make_filename(path,NULL);
else
tmppath=make_filename(GNUPG_LIBDIR,path,NULL);
}
else
tmppath=m_strdup(path);
/* It's okay if the file doesn't exist */
if(stat(tmppath,&statbuf)!=0)
{
ret=0;
goto end;
}
isdir=S_ISDIR(statbuf.st_mode);
/* Per-user files must be owned by the user. Extensions must be
owned by the user or root. */
if((!extension && statbuf.st_uid != getuid()) ||
(extension && statbuf.st_uid!=0 && statbuf.st_uid!=getuid()))
{
if(!checkonly)
log_info(_("Warning: unsafe ownership on %s \"%s\"\n"),
isdir?"directory":extension?"extension":"file",path);
goto end;
}
/* This works for both directories and files - basically, we don't
care what the owner permissions are, so long as the group and
other permissions are 0 for per-user files, and non-writable for
extensions. */
if((extension && (statbuf.st_mode & (S_IWGRP|S_IWOTH)) !=0) ||
(!extension && (statbuf.st_mode & (S_IRWXG|S_IRWXO)) != 0))
{
char *dir;
/* However, if the directory the directory/file is in is owned
by the user and is 700, then this is not a problem.
Theoretically, we could walk this test up to the root
directory /, but for the sake of sanity, I'm stopping at one
level down. */
dir= make_dirname (tmppath);
if(stat(dir,&statbuf)==0 && statbuf.st_uid==getuid() &&
S_ISDIR(statbuf.st_mode) && (statbuf.st_mode & (S_IRWXG|S_IRWXO))==0)
{
xfree (dir);
ret=0;
goto end;
}
m_free(dir);
if(!checkonly)
log_info(_("Warning: unsafe permissions on %s \"%s\"\n"),
isdir?"directory":extension?"extension":"file",path);
goto end;
}
ret=0;
end:
m_free(tmppath);
return ret;
#endif /* HAVE_STAT && !HAVE_DOSISH_SYSTEM */
return 0;
}
#endif
/* Wrapper around the usual sleep function. This one won't wake up
before the sleep time has really elapsed. When build with Pth it
merely calls pth_sleep and thus suspends only the current
thread. */
void
gnupg_sleep (unsigned int seconds)
{
#ifdef USE_NPTH
npth_sleep (seconds);
#else
/* Fixme: make sure that a sleep won't wake up to early. */
# ifdef HAVE_W32_SYSTEM
Sleep (seconds*1000);
# else
sleep (seconds);
# endif
#endif
}
/* Wrapper around the platforms usleep function. This one won't wake
* up before the sleep time has really elapsed. When build with nPth
* it merely calls npth_usleep and thus suspends only the current
* thread. */
void
gnupg_usleep (unsigned int usecs)
{
#if defined(USE_NPTH)
npth_usleep (usecs);
#elif defined(HAVE_W32_SYSTEM)
Sleep ((usecs + 999) / 1000);
#elif defined(HAVE_NANOSLEEP)
if (usecs)
{
struct timespec req;
struct timespec rem;
req.tv_sec = usecs / 1000000;
req.tv_nsec = (usecs % 1000000) * 1000;
while (nanosleep (&req, &rem) < 0 && errno == EINTR)
req = rem;
}
#else /*Standard Unix*/
if (usecs)
{
struct timeval tv;
tv.tv_sec = usecs / 1000000;
tv.tv_usec = usecs % 1000000;
select (0, NULL, NULL, NULL, &tv);
}
#endif
}
/* This function is a NOP for POSIX systems but required under Windows
as the file handles as returned by OS calls (like CreateFile) are
different from the libc file descriptors (like open). This function
translates system file handles to libc file handles. FOR_WRITE
gives the direction of the handle. */
int
translate_sys2libc_fd (gnupg_fd_t fd, int for_write)
{
#if defined(HAVE_W32CE_SYSTEM)
(void)for_write;
return (int) fd;
#elif defined(HAVE_W32_SYSTEM)
int x;
if (fd == GNUPG_INVALID_FD)
return -1;
/* Note that _open_osfhandle is currently defined to take and return
a long. */
x = _open_osfhandle ((intptr_t)fd, for_write ? 1 : 0);
if (x == -1)
log_error ("failed to translate osfhandle %p\n", (void *) fd);
return x;
#else /*!HAVE_W32_SYSTEM */
(void)for_write;
return fd;
#endif
}
/* This is the same as translate_sys2libc_fd but takes an integer
which is assumed to be such an system handle. On WindowsCE the
passed FD is a rendezvous ID and the function finishes the pipe
creation. */
int
translate_sys2libc_fd_int (int fd, int for_write)
{
#if HAVE_W32CE_SYSTEM
fd = (int) _assuan_w32ce_finish_pipe (fd, for_write);
return translate_sys2libc_fd ((void*)fd, for_write);
#elif HAVE_W32_SYSTEM
if (fd <= 2)
return fd; /* Do not do this for error, stdin, stdout, stderr. */
return translate_sys2libc_fd ((void*)fd, for_write);
#else
(void)for_write;
return fd;
#endif
}
/* Check whether FNAME has the form "-&nnnn", where N is a non-zero
* number. Returns this number or -1 if it is not the case. If the
* caller wants to use the file descriptor for writing FOR_WRITE shall
* be set to 1. If NOTRANSLATE is set the Windows specific mapping is
* not done. */
int
check_special_filename (const char *fname, int for_write, int notranslate)
{
if (allow_special_filenames
&& fname && *fname == '-' && fname[1] == '&')
{
int i;
fname += 2;
for (i=0; digitp (fname+i); i++ )
;
if (!fname[i])
return notranslate? atoi (fname)
/**/ : translate_sys2libc_fd_int (atoi (fname), for_write);
}
return -1;
}
/* Replacement for tmpfile(). This is required because the tmpfile
function of Windows' runtime library is broken, insecure, ignores
TMPDIR and so on. In addition we create a file with an inheritable
handle. */
FILE *
gnupg_tmpfile (void)
{
#ifdef HAVE_W32_SYSTEM
int attempts, n;
#ifdef HAVE_W32CE_SYSTEM
wchar_t buffer[MAX_PATH+7+12+1];
# define mystrlen(a) wcslen (a)
wchar_t *name, *p;
#else
char buffer[MAX_PATH+7+12+1];
# define mystrlen(a) strlen (a)
char *name, *p;
#endif
HANDLE file;
int pid = GetCurrentProcessId ();
unsigned int value;
int i;
SECURITY_ATTRIBUTES sec_attr;
memset (&sec_attr, 0, sizeof sec_attr );
sec_attr.nLength = sizeof sec_attr;
sec_attr.bInheritHandle = TRUE;
n = GetTempPath (MAX_PATH+1, buffer);
if (!n || n > MAX_PATH || mystrlen (buffer) > MAX_PATH)
{
gpg_err_set_errno (ENOENT);
return NULL;
}
p = buffer + mystrlen (buffer);
#ifdef HAVE_W32CE_SYSTEM
wcscpy (p, L"_gnupg");
p += 7;
#else
p = stpcpy (p, "_gnupg");
#endif
/* We try to create the directory but don't care about an error as
it may already exist and the CreateFile would throw an error
anyway. */
CreateDirectory (buffer, NULL);
*p++ = '\\';
name = p;
for (attempts=0; attempts < 10; attempts++)
{
p = name;
value = (GetTickCount () ^ ((pid<<16) & 0xffff0000));
for (i=0; i < 8; i++)
{
*p++ = tohex (((value >> 28) & 0x0f));
value <<= 4;
}
#ifdef HAVE_W32CE_SYSTEM
wcscpy (p, L".tmp");
#else
strcpy (p, ".tmp");
#endif
file = CreateFile (buffer,
GENERIC_READ | GENERIC_WRITE,
0,
&sec_attr,
CREATE_NEW,
FILE_ATTRIBUTE_TEMPORARY | FILE_FLAG_DELETE_ON_CLOSE,
NULL);
if (file != INVALID_HANDLE_VALUE)
{
FILE *fp;
#ifdef HAVE_W32CE_SYSTEM
int fd = (int)file;
fp = _wfdopen (fd, L"w+b");
#else
int fd = _open_osfhandle ((intptr_t)file, 0);
if (fd == -1)
{
CloseHandle (file);
return NULL;
}
fp = fdopen (fd, "w+b");
#endif
if (!fp)
{
int save = errno;
close (fd);
gpg_err_set_errno (save);
return NULL;
}
return fp;
}
Sleep (1); /* One ms as this is the granularity of GetTickCount. */
}
gpg_err_set_errno (ENOENT);
return NULL;
#undef mystrlen
#else /*!HAVE_W32_SYSTEM*/
return tmpfile ();
#endif /*!HAVE_W32_SYSTEM*/
}
/* Make sure that the standard file descriptors are opened. Obviously
some folks close them before an exec and the next file we open will
get one of them assigned and thus any output (i.e. diagnostics) end
up in that file (e.g. the trustdb). Not actually a gpg problem as
this will happen with almost all utilities when called in a wrong
way. However we try to minimize the damage here and raise
awareness of the problem.
Must be called before we open any files! */
void
gnupg_reopen_std (const char *pgmname)
{
#ifdef F_GETFD
int did_stdin = 0;
int did_stdout = 0;
int did_stderr = 0;
FILE *complain;
if (fcntl (STDIN_FILENO, F_GETFD) == -1 && errno ==EBADF)
{
if (open ("/dev/null",O_RDONLY) == STDIN_FILENO)
did_stdin = 1;
else
did_stdin = 2;
}
if (fcntl (STDOUT_FILENO, F_GETFD) == -1 && errno == EBADF)
{
if (open ("/dev/null",O_WRONLY) == STDOUT_FILENO)
did_stdout = 1;
else
did_stdout = 2;
}
if (fcntl (STDERR_FILENO, F_GETFD)==-1 && errno==EBADF)
{
if (open ("/dev/null", O_WRONLY) == STDERR_FILENO)
did_stderr = 1;
else
did_stderr = 2;
}
/* It's hard to log this sort of thing since the filehandle we would
complain to may be closed... */
if (!did_stderr)
complain = stderr;
else if (!did_stdout)
complain = stdout;
else
complain = NULL;
if (complain)
{
if (did_stdin == 1)
fprintf (complain, "%s: WARNING: standard input reopened\n", pgmname);
if (did_stdout == 1)
fprintf (complain, "%s: WARNING: standard output reopened\n", pgmname);
if (did_stderr == 1)
fprintf (complain, "%s: WARNING: standard error reopened\n", pgmname);
if (did_stdin == 2 || did_stdout == 2 || did_stderr == 2)
fprintf(complain,"%s: fatal: unable to reopen standard input,"
" output, or error\n", pgmname);
}
if (did_stdin == 2 || did_stdout == 2 || did_stderr == 2)
exit (3);
#else /* !F_GETFD */
(void)pgmname;
#endif
}
/* Inhibit calls to AllowSetForegroundWindow on Windows. Calling this
* with YES set to true calls to gnupg_allow_set_foregound_window are
* shunted. */
void
gnupg_inhibit_set_foregound_window (int yes)
{
#ifdef HAVE_W32_SYSTEM
inhibit_set_foregound_window = yes;
#else
(void)yes;
#endif
}
/* Hack required for Windows. */
void
gnupg_allow_set_foregound_window (pid_t pid)
{
if (!pid)
log_info ("%s called with invalid pid %lu\n",
"gnupg_allow_set_foregound_window", (unsigned long)pid);
#if defined(HAVE_W32_SYSTEM) && !defined(HAVE_W32CE_SYSTEM)
else if (inhibit_set_foregound_window)
;
else if (!AllowSetForegroundWindow ((pid_t)pid == (pid_t)(-1)?ASFW_ANY:pid))
log_info ("AllowSetForegroundWindow(%lu) failed: %s\n",
(unsigned long)pid, w32_strerror (-1));
#endif
}
int
gnupg_remove (const char *fname)
{
#ifdef HAVE_W32CE_SYSTEM
int rc;
wchar_t *wfname;
wfname = utf8_to_wchar (fname);
if (!wfname)
rc = 0;
else
{
rc = DeleteFile (wfname);
xfree (wfname);
}
if (!rc)
return -1; /* ERRNO is automagically provided by gpg-error.h. */
return 0;
#else
return remove (fname);
#endif
}
/* Wrapper for rename(2) to handle Windows peculiarities. If
* BLOCK_SIGNALS is not NULL and points to a variable set to true, all
* signals will be blocked by calling gnupg_block_all_signals; the
* caller needs to call gnupg_unblock_all_signals if that variable is
* still set to true on return. */
gpg_error_t
gnupg_rename_file (const char *oldname, const char *newname, int *block_signals)
{
gpg_error_t err = 0;
if (block_signals && *block_signals)
gnupg_block_all_signals ();
#ifdef HAVE_DOSISH_SYSTEM
{
int wtime = 0;
gnupg_remove (newname);
again:
if (rename (oldname, newname))
{
if (GetLastError () == ERROR_SHARING_VIOLATION)
{
/* Another process has the file open. We do not use a
* lock for read but instead we wait until the other
* process has closed the file. This may take long but
* that would also be the case with a dotlock approach for
* read and write. Note that we don't need this on Unix
* due to the inode concept.
*
* So let's wait until the rename has worked. The retry
* intervals are 50, 100, 200, 400, 800, 50ms, ... */
if (!wtime || wtime >= 800)
wtime = 50;
else
wtime *= 2;
if (wtime >= 800)
log_info (_("waiting for file '%s' to become accessible ...\n"),
oldname);
Sleep (wtime);
goto again;
}
err = my_error_from_syserror ();
}
}
#else /* Unix */
{
#ifdef __riscos__
gnupg_remove (newname);
#endif
if (rename (oldname, newname) )
err = my_error_from_syserror ();
}
#endif /* Unix */
if (block_signals && *block_signals && err)
{
gnupg_unblock_all_signals ();
*block_signals = 0;
}
if (err)
log_error (_("renaming '%s' to '%s' failed: %s\n"),
oldname, newname, gpg_strerror (err));
return err;
}
#ifndef HAVE_W32_SYSTEM
static mode_t
modestr_to_mode (const char *modestr, mode_t oldmode)
{
static struct {
char letter;
mode_t value;
} table[] = { { '-', 0 },
{ 'r', S_IRUSR }, { 'w', S_IWUSR }, { 'x', S_IXUSR },
{ 'r', S_IRGRP }, { 'w', S_IWGRP }, { 'x', S_IXGRP },
{ 'r', S_IROTH }, { 'w', S_IWOTH }, { 'x', S_IXOTH } };
int idx;
mode_t mode = 0;
/* For now we only support a string as used by ls(1) and no octal
* numbers. The first character must be a dash. */
for (idx=0; idx < 10 && *modestr; idx++, modestr++)
{
if (*modestr == table[idx].letter)
mode |= table[idx].value;
else if (*modestr == '.')
{
if (!idx)
; /* Skip the dummy. */
else if ((oldmode & table[idx].value))
mode |= (oldmode & table[idx].value);
else
mode &= ~(oldmode & table[idx].value);
}
else if (*modestr != '-')
break;
}
return mode;
}
#endif
/* A wrapper around mkdir which takes a string for the mode argument.
This makes it easier to handle the mode argument which is not
defined on all systems. The format of the modestring is
"-rwxrwxrwx"
'-' is a don't care or not set. 'r', 'w', 'x' are read allowed,
write allowed, execution allowed with the first group for the user,
the second for the group and the third for all others. If the
string is shorter than above the missing mode characters are meant
to be not set. */
int
gnupg_mkdir (const char *name, const char *modestr)
{
/* Note that gpgrt_mkdir also sets ERRNO in addition to returing an
* gpg-error style error code. */
return gpgrt_mkdir (name, modestr);
}
/* A simple wrapper around chdir. NAME is expected to be utf8
* encoded. */
int
gnupg_chdir (const char *name)
{
/* Note that gpgrt_chdir also sets ERRNO in addition to returing an
* gpg-error style error code. */
return gpgrt_chdir (name);
}
/* A wrapper around chmod which takes a string for the mode argument.
This makes it easier to handle the mode argument which is not
defined on all systems. The format of the modestring is the same
as for gnupg_mkdir with extra feature that a '.' keeps the original
mode bit. */
int
gnupg_chmod (const char *name, const char *modestr)
{
#ifdef HAVE_W32_SYSTEM
(void)name;
(void)modestr;
return 0;
#else
mode_t oldmode;
if (strchr (modestr, '.'))
{
/* Get the old mode so that a '.' can copy that bit. */
struct stat st;
if (stat (name, &st))
return -1;
oldmode = st.st_mode;
}
else
oldmode = 0;
return chmod (name, modestr_to_mode (modestr, oldmode));
#endif
}
/* Our version of mkdtemp. The API is identical to POSIX.1-2008
version. We do not use a system provided mkdtemp because we have a
good RNG instantly available and this way we don't have diverging
versions. */
char *
gnupg_mkdtemp (char *tmpl)
{
/* A lower bound on the number of temporary files to attempt to
generate. The maximum total number of temporary file names that
can exist for a given template is 62**6 (5*36**3 for Windows).
It should never be necessary to try all these combinations.
Instead if a reasonable number of names is tried (we define
reasonable as 62**3 or 5*36**3) fail to give the system
administrator the chance to remove the problems. */
#ifdef HAVE_W32_SYSTEM
static const char letters[] =
"abcdefghijklmnopqrstuvwxyz0123456789";
# define NUMBER_OF_LETTERS 36
# define ATTEMPTS_MIN (5 * 36 * 36 * 36)
#else
static const char letters[] =
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
# define NUMBER_OF_LETTERS 62
# define ATTEMPTS_MIN (62 * 62 * 62)
#endif
int len;
char *XXXXXX;
uint64_t value;
unsigned int count;
int save_errno = errno;
/* The number of times to attempt to generate a temporary file. To
conform to POSIX, this must be no smaller than TMP_MAX. */
#if ATTEMPTS_MIN < TMP_MAX
unsigned int attempts = TMP_MAX;
#else
unsigned int attempts = ATTEMPTS_MIN;
#endif
len = strlen (tmpl);
if (len < 6 || strcmp (&tmpl[len - 6], "XXXXXX"))
{
gpg_err_set_errno (EINVAL);
return NULL;
}
/* This is where the Xs start. */
XXXXXX = &tmpl[len - 6];
/* Get a random start value. */
gcry_create_nonce (&value, sizeof value);
/* Loop until a directory was created. */
for (count = 0; count < attempts; value += 7777, ++count)
{
uint64_t v = value;
/* Fill in the random bits. */
XXXXXX[0] = letters[v % NUMBER_OF_LETTERS];
v /= NUMBER_OF_LETTERS;
XXXXXX[1] = letters[v % NUMBER_OF_LETTERS];
v /= NUMBER_OF_LETTERS;
XXXXXX[2] = letters[v % NUMBER_OF_LETTERS];
v /= NUMBER_OF_LETTERS;
XXXXXX[3] = letters[v % NUMBER_OF_LETTERS];
v /= NUMBER_OF_LETTERS;
XXXXXX[4] = letters[v % NUMBER_OF_LETTERS];
v /= NUMBER_OF_LETTERS;
XXXXXX[5] = letters[v % NUMBER_OF_LETTERS];
if (!gnupg_mkdir (tmpl, "-rwx"))
{
gpg_err_set_errno (save_errno);
return tmpl;
}
if (errno != EEXIST)
return NULL;
}
/* We got out of the loop because we ran out of combinations to try. */
gpg_err_set_errno (EEXIST);
return NULL;
}
int
gnupg_setenv (const char *name, const char *value, int overwrite)
{
#ifdef HAVE_W32CE_SYSTEM
(void)name;
(void)value;
(void)overwrite;
return 0;
#else /*!W32CE*/
# ifdef HAVE_W32_SYSTEM
/* Windows maintains (at least) two sets of environment variables.
One set can be accessed by GetEnvironmentVariable and
SetEnvironmentVariable. This set is inherited by the children.
The other set is maintained in the C runtime, and is accessed
using getenv and putenv. We try to keep them in sync by
modifying both sets. */
{
int exists;
char tmpbuf[10];
exists = GetEnvironmentVariable (name, tmpbuf, sizeof tmpbuf);
if ((! exists || overwrite) && !SetEnvironmentVariable (name, value))
{
gpg_err_set_errno (EINVAL); /* (Might also be ENOMEM.) */
return -1;
}
}
# endif /*W32*/
# ifdef HAVE_SETENV
return setenv (name, value, overwrite);
# else /*!HAVE_SETENV*/
if (! getenv (name) || overwrite)
{
char *buf;
(void)overwrite;
if (!name || !value)
{
gpg_err_set_errno (EINVAL);
return -1;
}
buf = strconcat (name, "=", value, NULL);
if (!buf)
return -1;
# if __GNUC__
# warning no setenv - using putenv but leaking memory.
# endif
return putenv (buf);
}
return 0;
# endif /*!HAVE_SETENV*/
#endif /*!W32CE*/
}
int
gnupg_unsetenv (const char *name)
{
#ifdef HAVE_W32CE_SYSTEM
(void)name;
return 0;
#else /*!W32CE*/
# ifdef HAVE_W32_SYSTEM
/* Windows maintains (at least) two sets of environment variables.
One set can be accessed by GetEnvironmentVariable and
SetEnvironmentVariable. This set is inherited by the children.
The other set is maintained in the C runtime, and is accessed
using getenv and putenv. We try to keep them in sync by
modifying both sets. */
if (!SetEnvironmentVariable (name, NULL))
{
gpg_err_set_errno (EINVAL); /* (Might also be ENOMEM.) */
return -1;
}
# endif /*W32*/
# ifdef HAVE_UNSETENV
return unsetenv (name);
# else /*!HAVE_UNSETENV*/
{
char *buf;
if (!name)
{
gpg_err_set_errno (EINVAL);
return -1;
}
buf = xtrystrdup (name);
if (!buf)
return -1;
# if __GNUC__
# warning no unsetenv - trying putenv but leaking memory.
# endif
return putenv (buf);
}
# endif /*!HAVE_UNSETENV*/
#endif /*!W32CE*/
}
/* Return the current working directory as a malloced string. Return
NULL and sets ERRNo on error. */
char *
gnupg_getcwd (void)
{
char *buffer;
size_t size = 100;
for (;;)
{
buffer = xtrymalloc (size+1);
if (!buffer)
return NULL;
#ifdef HAVE_W32CE_SYSTEM
strcpy (buffer, "/"); /* Always "/". */
return buffer;
#else
if (getcwd (buffer, size) == buffer)
return buffer;
xfree (buffer);
if (errno != ERANGE)
return NULL;
size *= 2;
#endif
}
}
/* Try to set an envvar. Print only a notice on error. */
static void
try_set_envvar (const char *name, const char *value, int silent)
{
if (gnupg_setenv (name, value, 1))
if (!silent)
log_info ("error setting envvar %s to '%s': %s\n", name, value,
gpg_strerror (my_error_from_syserror ()));
}
/* Switch to USER which is either a name or an UID. This is a nop
* under Windows. Note that in general it is only possible to switch
* to another user id if the process is running under root. if silent
* is set no diagnostics are printed. */
gpg_error_t
gnupg_chuid (const char *user, int silent)
{
#ifdef HAVE_W32_SYSTEM
(void)user; /* Not implemented for Windows - ignore. */
(void)silent;
return 0;
#elif HAVE_PWD_H /* A proper Unix */
unsigned long ul;
struct passwd *pw;
struct stat st;
char *endp;
gpg_error_t err;
gpg_err_set_errno (0);
ul = strtoul (user, &endp, 10);
if (errno || endp == user || *endp)
pw = getpwnam (user); /* Not a number; assume USER is a name. */
else
pw = getpwuid ((uid_t)ul);
if (!pw)
{
if (!silent)
log_error ("user '%s' not found\n", user);
return my_error (GPG_ERR_NOT_FOUND);
}
/* Try to set some envvars even if we are already that user. */
if (!stat (pw->pw_dir, &st))
try_set_envvar ("HOME", pw->pw_dir, silent);
try_set_envvar ("USER", pw->pw_name, silent);
try_set_envvar ("LOGNAME", pw->pw_name, silent);
#ifdef _AIX
try_set_envvar ("LOGIN", pw->pw_name, silent);
#endif
if (getuid () == pw->pw_uid)
return 0; /* We are already this user. */
/* If we need to switch set PATH to a standard value and make sure
* GNUPGHOME is not set. */
try_set_envvar ("PATH", "/usr/local/bin:/usr/bin:/bin", silent);
if (gnupg_unsetenv ("GNUPGHOME"))
if (!silent)
log_info ("error unsetting envvar %s: %s\n", "GNUPGHOME",
gpg_strerror (gpg_error_from_syserror ()));
if (initgroups (pw->pw_name, pw->pw_gid))
{
err = my_error_from_syserror ();
if (!silent)
log_error ("error setting supplementary groups for '%s': %s\n",
pw->pw_name, gpg_strerror (err));
return err;
}
if (setuid (pw->pw_uid))
{
err = my_error_from_syserror ();
log_error ("error switching to user '%s': %s\n",
pw->pw_name, gpg_strerror (err));
return err;
}
return 0;
#else /*!HAVE_PWD_H */
if (!silent)
log_info ("system is missing passwd querying functions\n");
return my_error (GPG_ERR_NOT_IMPLEMENTED);
#endif
}
#ifdef HAVE_W32CE_SYSTEM
/* There is a isatty function declaration in cegcc but it does not
make sense, thus we redefine it. */
int
_gnupg_isatty (int fd)
{
(void)fd;
return 0;
}
#endif
#ifdef HAVE_W32CE_SYSTEM
/* Replacement for getenv which takes care of the our use of getenv.
The code is not thread safe but we expect it to work in all cases
because it is called for the first time early enough. */
char *
_gnupg_getenv (const char *name)
{
static int initialized;
static char *assuan_debug;
if (!initialized)
{
assuan_debug = read_w32_registry_string (NULL,
"\\Software\\GNU\\libassuan",
"debug");
initialized = 1;
}
if (!strcmp (name, "ASSUAN_DEBUG"))
return assuan_debug;
else
return NULL;
}
#endif /*HAVE_W32CE_SYSTEM*/
#ifdef HAVE_W32_SYSTEM
/* Return the user's security identifier from the current process. */
PSID
w32_get_user_sid (void)
{
int okay = 0;
HANDLE proc = NULL;
HANDLE token = NULL;
TOKEN_USER *user = NULL;
PSID sid = NULL;
DWORD tokenlen, sidlen;
proc = OpenProcess (PROCESS_QUERY_INFORMATION, FALSE, GetCurrentProcessId());
if (!proc)
goto leave;
if (!OpenProcessToken (proc, TOKEN_QUERY, &token))
goto leave;
if (!GetTokenInformation (token, TokenUser, NULL, 0, &tokenlen)
&& GetLastError() != ERROR_INSUFFICIENT_BUFFER)
goto leave;
user = xtrymalloc (tokenlen);
if (!user)
goto leave;
if (!GetTokenInformation (token, TokenUser, user, tokenlen, &tokenlen))
goto leave;
if (!IsValidSid (user->User.Sid))
goto leave;
sidlen = GetLengthSid (user->User.Sid);
sid = xtrymalloc (sidlen);
if (!sid)
goto leave;
if (!CopySid (sidlen, sid, user->User.Sid))
goto leave;
okay = 1;
leave:
xfree (user);
if (token)
CloseHandle (token);
if (proc)
CloseHandle (proc);
if (!okay)
{
xfree (sid);
sid = NULL;
}
return sid;
}
#endif /*HAVE_W32_SYSTEM*/
/* Support for inotify under Linux. */
/* Store a new inotify file handle for FNAME at R_FD or return an
* error code. This file descriptor watch the removal of FNAME. */
gpg_error_t
gnupg_inotify_watch_delete_self (int *r_fd, const char *fname)
{
#if HAVE_INOTIFY_INIT
gpg_error_t err;
int fd;
*r_fd = -1;
if (!fname)
return my_error (GPG_ERR_INV_VALUE);
fd = inotify_init ();
if (fd == -1)
return my_error_from_syserror ();
if (inotify_add_watch (fd, fname, IN_DELETE_SELF) == -1)
{
err = my_error_from_syserror ();
close (fd);
return err;
}
*r_fd = fd;
return 0;
#else /*!HAVE_INOTIFY_INIT*/
(void)fname;
*r_fd = -1;
return my_error (GPG_ERR_NOT_SUPPORTED);
#endif /*!HAVE_INOTIFY_INIT*/
}
/* Store a new inotify file handle for SOCKET_NAME at R_FD or return
* an error code. */
gpg_error_t
gnupg_inotify_watch_socket (int *r_fd, const char *socket_name)
{
#if HAVE_INOTIFY_INIT
gpg_error_t err;
char *fname;
int fd;
char *p;
*r_fd = -1;
if (!socket_name)
return my_error (GPG_ERR_INV_VALUE);
fname = xtrystrdup (socket_name);
if (!fname)
return my_error_from_syserror ();
fd = inotify_init ();
if (fd == -1)
{
err = my_error_from_syserror ();
xfree (fname);
return err;
}
/* We need to watch the directory for the file because there won't
* be an IN_DELETE_SELF for a socket file. To handle a removal of
* the directory we also watch the directory itself. */
p = strrchr (fname, '/');
if (p)
*p = 0;
if (inotify_add_watch (fd, fname,
(IN_DELETE|IN_DELETE_SELF|IN_EXCL_UNLINK)) == -1)
{
err = my_error_from_syserror ();
close (fd);
xfree (fname);
return err;
}
xfree (fname);
*r_fd = fd;
return 0;
#else /*!HAVE_INOTIFY_INIT*/
(void)socket_name;
*r_fd = -1;
return my_error (GPG_ERR_NOT_SUPPORTED);
#endif /*!HAVE_INOTIFY_INIT*/
}
/* Read an inotify event and return true if it matches NAME or if it
* sees an IN_DELETE_SELF event for the directory of NAME. */
int
gnupg_inotify_has_name (int fd, const char *name)
{
#if USE_NPTH && HAVE_INOTIFY_INIT
#define BUFSIZE_FOR_INOTIFY (sizeof (struct inotify_event) + 255 + 1)
union {
struct inotify_event ev;
char _buf[sizeof (struct inotify_event) + 255 + 1];
} buf;
struct inotify_event *evp;
int n;
n = npth_read (fd, &buf, sizeof buf);
/* log_debug ("notify read: n=%d\n", n); */
evp = &buf.ev;
while (n >= sizeof (struct inotify_event))
{
/* log_debug (" mask=%x len=%u name=(%s)\n", */
/* evp->mask, (unsigned int)evp->len, evp->len? evp->name:""); */
if ((evp->mask & IN_UNMOUNT))
{
/* log_debug (" found (dir unmounted)\n"); */
return 3; /* Directory was unmounted. */
}
if ((evp->mask & IN_DELETE_SELF))
{
/* log_debug (" found (dir removed)\n"); */
return 2; /* Directory was removed. */
}
if ((evp->mask & IN_DELETE))
{
if (evp->len >= strlen (name) && !strcmp (evp->name, name))
{
/* log_debug (" found (file removed)\n"); */
return 1; /* File was removed. */
}
}
n -= sizeof (*evp) + evp->len;
evp = (struct inotify_event *)(void *)
((char *)evp + sizeof (*evp) + evp->len);
}
#else /*!(USE_NPTH && HAVE_INOTIFY_INIT)*/
(void)fd;
(void)name;
#endif /*!(USE_NPTH && HAVE_INOTIFY_INIT)*/
return 0; /* Not found. */
}
/* Return a malloc'ed string that is the path to the passed
* unix-domain socket (or return NULL if this is not a valid
* unix-domain socket). We use a plain int here because it is only
* used on Linux.
*
* FIXME: This function needs to be moved to libassuan. */
#ifndef HAVE_W32_SYSTEM
char *
gnupg_get_socket_name (int fd)
{
struct sockaddr_un un;
socklen_t len = sizeof(un);
char *name = NULL;
if (getsockname (fd, (struct sockaddr*)&un, &len) != 0)
log_error ("could not getsockname(%d): %s\n", fd,
gpg_strerror (my_error_from_syserror ()));
else if (un.sun_family != AF_UNIX)
log_error ("file descriptor %d is not a unix-domain socket\n", fd);
else if (len <= offsetof (struct sockaddr_un, sun_path))
log_error ("socket name not present for file descriptor %d\n", fd);
else if (len > sizeof(un))
log_error ("socket name for file descriptor %d was truncated "
"(passed %zu bytes, wanted %u)\n", fd, sizeof(un), len);
else
{
size_t namelen = len - offsetof (struct sockaddr_un, sun_path);
/* log_debug ("file descriptor %d has path %s (%zu octets)\n", fd, */
/* un.sun_path, namelen); */
name = xtrymalloc (namelen + 1);
if (!name)
log_error ("failed to allocate memory for name of fd %d: %s\n",
fd, gpg_strerror (my_error_from_syserror ()));
else
{
memcpy (name, un.sun_path, namelen);
name[namelen] = 0;
}
}
return name;
}
#endif /*!HAVE_W32_SYSTEM*/
/* Check whether FD is valid. */
int
gnupg_fd_valid (int fd)
{
int d = dup (fd);
if (d < 0)
return 0;
close (d);
return 1;
}
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