47 lines
1.3 KiB
Plaintext
47 lines
1.3 KiB
Plaintext
What is it?
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===========
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This is a standalone implementation of fortify source[0]. It is libc-agnostic
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and simply overlays the system headers by using the #include_next extension found
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in GCC and clang. It was initially designed to be used on musl[1] based Linux
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distributions.
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Features
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========
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- It is portable, works on *BSD and Linux systems.
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- It will only trap non-conformant programs. This means that fortify
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level 2 is treated in the same way as level 1.
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- Avoids making function calls when UB has already been invoked. This
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is handled by using __builtin_trap().
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- Check functions for out-of-bounds read interfaces, such as send(),
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write(), fwrite() etc.
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- No ABI is enforced. All of the check functions are inlined into the
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resulting binary.
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Sample usage
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============
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A plan for integrating fortify into a system is still in planning stages.
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If you want to quickly test it, you can try something like the following:
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cat > fgets.c <<EOF
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#include <stdio.h>
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int
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main(void)
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{
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char buf[BUFSIZ];
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fgets(buf, sizeof(buf) + 1, stdin);
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return 0;
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}
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EOF
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cc -I<path-to-fortify-include-dir> -D_FORTIFY_SOURCE=1 -O1 fgets.c
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./a.out
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At this point, the program will crash.
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[0] http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html
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[1] http://www.musl-libc.org/
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