optool is a tool which interfaces with MachO binaries in order to insert/remove load commands, strip code signatures, resign, and remove aslr. Below is its help.
optool v0.1 USAGE: install -c <command> -p <payload> -t <target> [-o=<output>] [-b] [--resign] In serts an LC_LOAD command into the target binary which points to the payload. T his may render some executables unusable. uninstall -p <payload> -t <target> [-o=<output>] [-b] [--resign] Removes any L C_LOAD commands which point to a given payload from the target binary. This ma y render some executables unusable. strip [-w] -t <target> Removes a code signature load command from the given bi nary. restore -t <target> Restores any backup made on the target by this tool. aslr -t <target> [-o=<output>] [-b] [--resign] Removes an ASLR flag from the m acho header if it exists. This may render some executables unusable OPTIONS: [-w --weak] Used with the STRIP command to weakly remove the signature. Withou t this, the code signature is replaced with null bytes on the binary and its L OAD command is removed. [--resign] Try to repair the code signature after any operations are done. Thi s may render some executables unusable. -t|--target <target> Required of all commands to specify the target executable to modify -p|--payload <payload> Required of the INSTALL and UNINSTALL commands to speci fy the path to a DYLIB to point the LOAD command to [-c --command] Specify which type of load command to use in INSTALL. Can be re export for LC_REEXPORT_DYLIB, weak for LC_LOAD_WEAK_DYLIB, upward for LC_LOAD_ UPWARD_DYLIB, or load for LC_LOAD_DYLIB [-b --backup] Backup the executable to a suffixed path (in the form of _backup .BUNDLEVERSION) [-h --help] Show this message (C) 2014 Alexander S. Zielenski. Licensed under BSD
optool is licensed under BSD. Below is the license reproduced in its entirety:
Copyright (c) 2014, Alex Zielenski All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.