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55 lines
2.0 KiB
C
55 lines
2.0 KiB
C
/* Look up an environment variable, returning NULL in insecure situations.
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Copyright 2013-2017 Free Software Foundation, Inc.
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This program is free software: you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published
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by the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include <config.h>
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#include <stdlib.h>
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#if !HAVE___SECURE_GETENV
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# if HAVE_ISSETUGID || (HAVE_GETUID && HAVE_GETEUID && HAVE_GETGID && HAVE_GETEGID)
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# include <unistd.h>
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# endif
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#endif
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char *
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secure_getenv (char const *name)
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{
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#if HAVE___SECURE_GETENV /* glibc */
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return __secure_getenv (name);
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#elif HAVE_ISSETUGID /* OS X, FreeBSD, NetBSD, OpenBSD */
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if (issetugid ())
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return NULL;
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return getenv (name);
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#elif HAVE_GETUID && HAVE_GETEUID && HAVE_GETGID && HAVE_GETEGID /* other Unix */
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if (geteuid () != getuid () || getegid () != getgid ())
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return NULL;
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return getenv (name);
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#elif (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ /* native Windows */
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/* On native Windows, there is no such concept as setuid or setgid binaries.
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- Programs launched as system services have high privileges, but they don't
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inherit environment variables from a user.
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- Programs launched by a user with "Run as Administrator" have high
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privileges and use the environment variables, but the user has been asked
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whether he agrees.
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- Programs launched by a user without "Run as Administrator" cannot gain
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high privileges, therefore there is no risk. */
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return getenv (name);
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#else
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return NULL;
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#endif
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}
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