NAME

       hardening-check - check binaries for security hardening features

SYNOPSIS

       hardening-check [options] [ELF ...]

       Examine a given set of ELF binaries and check for several security hardening features, failing if they
       are not all found.

DESCRIPTION

       This utility checks a given list of ELF binaries for several security hardening features that can be
       compiled into an executable. These features are:

       Position Independent Executable
               This indicates that the executable was built in such a way (PIE) that the "text" section of the
               program can be relocated in memory. To take full advantage of this feature, the executing kernel
               must support text Address Space Layout Randomization (ASLR).

       Stack Protected
               This indicates that there is evidence that the ELF was compiled with the gcc(1) option
               -fstack-protector (e.g. uses __stack_chk_fail). The program will be resistant to having its stack
               overflowed.

               When an executable was built without any character arrays being allocated on the stack, this
               check will lead to false alarms (since there is no use of __stack_chk_fail), even though it was
               compiled with the correct options.

       Fortify Source functions
               This indicates that the executable was compiled with -D_FORTIFY_SOURCE=2 and -O1 or higher. This
               causes certain unsafe glibc functions with their safer counterparts (e.g. strncpy instead of
               strcpy), or replaces calls that are verifiable at runtime with the runtime-check version (e.g.
               __memcpy_chk insteade of memcpy).

               When an executable was built such that the fortified versions of the glibc functions are not
               useful (e.g. use is verified as safe at compile time, or use cannot be verified at runtime), this
               check will lead to false alarms.  In an effort to mitigate this, the check will pass if any
               fortified function is found, and will fail if only unfortified functions are found. Uncheckable
               conditions also pass (e.g. no functions that could be fortified are found, or not linked against
               glibc).

       Read-only relocations
               This indicates that the executable was build with -Wl,-z,relro to have ELF markings (RELRO) that
               ask the runtime linker to mark any regions of the relocation table as "read-only" if they were
               resolved before execution begins. This reduces the possible areas of memory in a program that can
               be used by an attacker that performs a successful memory corruption exploit.

       Immediate binding
               This indicates that the executable was built with -Wl,-z,now to have ELF markings (BIND_NOW) that
               ask the runtime linker to resolve all relocations before starting program execution. When
               combined with RELRO above, this further reduces the regions of memory available to memory
               corruption attacks.

OPTIONS

       --nopie, -p
               No not require that the checked binaries be built as PIE.

       --nostackprotector, -s
               No not require that the checked binaries be built with the stack protector.

       --nofortify, -f
               No not require that the checked binaries be built with Fority Source.

       --norelro, -r
               No not require that the checked binaries be built with RELRO.

       --nobindnow, -b
               No not require that the checked binaries be built with BIND_NOW.

       --quiet, -q
               Only report failures.

       --verbose, -v
               Report verbosely on failures.

       --report-functions, -R
               After the report, display all external functions needed by the ELF.

       --find-libc-functions, -F
               Instead of the regular report, locate the libc for the first ELF on the command line and report
               all the known "fortified" functions exported by libc.

       --color, -c
               Enable colorized status output.

       --lintian, -l
               Switch reporting to lintian-check-parsable output.

       --debug Report some debugging during processing.

       --help, -h, -?
               Print a brief help message and exit.

       --man, -H
               Print the manual page and exit.

RETURN VALUE

       When all checked binaries have all checkable hardening features detected, this program will finish with
       an exit code of 0. If any check fails, the exit code with be 1. Individual checks can be disabled via
       command line options.

AUTHOR

       Kees Cook <kees@debian.org>

COPYRIGHT AND LICENSE

       Copyright 2009-2013 Kees Cook <kees@debian.org>.

       This program is free software; you can redistribute it and/or modify it under the terms of the GNU
       General Public License as published by the Free Software Foundation; version 2 or later.

SEE ALSO

       gcc(1), hardening-wrapper(1)