diff options
Diffstat (limited to 'common/sysutils.c')
| -rw-r--r-- | common/sysutils.c | 152 |
1 files changed, 143 insertions, 9 deletions
diff --git a/common/sysutils.c b/common/sysutils.c index 858cb6500..397184583 100644 --- a/common/sysutils.c +++ b/common/sysutils.c @@ -1,7 +1,7 @@ /* sysutils.c - system helpers - * Copyright (C) 1998, 1999, 2000, 2001, 2003, 2004, - * 2007, 2008 Free Software Foundation, Inc. - * Copyright (C) 2013 Werner Koch + * Copyright (C) 1991-2001, 2003-2004, + * 2006-2008 Free Software Foundation, Inc. + * Copyright (C) 2013-2014 Werner Koch * * This file is part of GnuPG. * @@ -38,6 +38,7 @@ #include <stdio.h> #include <stdlib.h> +#include <stdint.h> #include <string.h> #include <unistd.h> #include <errno.h> @@ -617,6 +618,90 @@ gnupg_mkdir (const char *name, const char *modestr) } +/* 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) { @@ -625,23 +710,72 @@ gnupg_setenv (const char *name, const char *value, int overwrite) (void)value; (void)overwrite; return 0; -#else +#elif defined(HAVE_W32_SYSTEM) + if (!overwrite) + { + char tmpbuf[10]; + if (GetEnvironmentVariable (name, tmpbuf, sizeof tmpbuf)) + return 0; /* Exists but overwrite was not requested. */ + } + if (!SetEnvironmentVariable (name, value)) + { + gpg_err_set_errno (EINVAL); /* (Might also be ENOMEM.) */ + return -1; + } + return 0; +#elif defined(HAVE_SETENV) return setenv (name, value, overwrite); +#else + char *buf; + + (void)overwrite; + if (!name || !value) + { + gpg_err_set_errno (EINVAL); + return -1; + } + buf = xtrymalloc (strlen (name) + 1 + strlen (value) + 1); + if (!buf) + return -1; + strcpy (stpcpy (stpcpy (buf, name), "="), value); +#if __GNUC__ +# warning no setenv - using putenv but leaking memory. +#endif + return putenv (buf); #endif } + int gnupg_unsetenv (const char *name) { #ifdef HAVE_W32CE_SYSTEM (void)name; return 0; -#else -# ifdef HAVE_UNSETENV +#elif defined(HAVE_W32_SYSTEM) + if (!SetEnvironmentVariable (name, NULL)) + { + gpg_err_set_errno (EINVAL); /* (Might also be ENOMEM.) */ + return -1; + } + return 0; +#elif defined(HAVE_UNSETENV) return unsetenv (name); -# else - return putenv (name); -# endif +#else + 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 } |