diff options
Diffstat (limited to 'gl/secure_getenv.c')
| -rw-r--r-- | gl/secure_getenv.c | 33 |
1 files changed, 21 insertions, 12 deletions
diff --git a/gl/secure_getenv.c b/gl/secure_getenv.c index 029441ed06..167d50b807 100644 --- a/gl/secure_getenv.c +++ b/gl/secure_getenv.c @@ -1,4 +1,4 @@ -/* Look up an environment variable more securely. +/* Look up an environment variable, returning NULL in insecure situations. Copyright 2013-2016 Free Software Foundation, Inc. @@ -20,26 +20,35 @@ #include <stdlib.h> #if !HAVE___SECURE_GETENV -# if HAVE_ISSETUGID +# if HAVE_ISSETUGID || (HAVE_GETUID && HAVE_GETEUID && HAVE_GETGID && HAVE_GETEGID) # include <unistd.h> -# else -# undef issetugid -# ifdef _WIN32 -# define issetugid() 0 -# else -# define issetugid() 1 -# endif # endif #endif char * secure_getenv (char const *name) { -#if HAVE___SECURE_GETENV +#if HAVE___SECURE_GETENV /* glibc */ return __secure_getenv (name); -#else +#elif HAVE_ISSETUGID /* OS X, FreeBSD, NetBSD, OpenBSD */ if (issetugid ()) - return 0; + return NULL; + return getenv (name); +#elif HAVE_GETUID && HAVE_GETEUID && HAVE_GETGID && HAVE_GETEGID /* other Unix */ + if (geteuid () != getuid () || getegid () != getgid ()) + return NULL; return getenv (name); +#elif (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ /* native Windows */ + /* On native Windows, there is no such concept as setuid or setgid binaries. + - Programs launched as system services have high privileges, but they don't + inherit environment variables from a user. + - Programs launched by a user with "Run as Administrator" have high + privileges and use the environment variables, but the user has been asked + whether he agrees. + - Programs launched by a user without "Run as Administrator" cannot gain + high privileges, therefore there is no risk. */ + return getenv (name); +#else + return NULL; #endif } |