Not only that, but there is no way to export the changes that
youmay have made within IDA back out to the original binary file. This is why assembly
and hex editing skills are essential for anyone who expects to do any binary patching.
Once a patched binary has been successfully created and tested, the problem of distributing
the binary remains. Any number of reasons exist that may preclude distribution
of the entire patched binary, ranging from prohibitive size to legal restrictions. One
tool for generating and applying binary patches is named Xdelta. Xdelta combines the
functionality of diff and patch into a single tool capable of being used on binary files.
Xdelta can generate the difference between any two files regardless of the type of those
files. When Xdelta is used, only the binary difference file (the ???delta???) needs to be distributed.
Recipients utilize Xdelta to update their binaries by applying the delta file to
their affected binary.
Limitations
File formats for executable files are very rigid in their structure. One of the toughest
problems to overcome when patching a binary is finding space to insert new code.
Unlike simple text files, you cannot simply turn on insert mode and paste in a sequence
of assembly language.
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