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https://github.com/libretro/x86-assembly-cheat.git
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Julian Squires
1ef175a682
According to the Intel instruction set reference manual, we need to check the carry flag after calling rdrand, and loop if it's not set.
29 lines
679 B
NASM
29 lines
679 B
NASM
; # RDRAND
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; True random number generator!
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; This Intel engineer says its based on quantum effects:
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; http://stackoverflow.com/a/18004959/895245
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; Generated some polemic when kernel devs wanted to use it as part of `/dev/random`,
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; because it could be used as a cryptographic backdoor by Intel since it is a black box.
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; rdrand sets the carry flag when data is ready; one must loop if
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; the carry flag isn't set, but unlike in this example, one should
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; bound the number of attempts.
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%include "lib/asm_io.inc"
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ENTRY
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.loop0:
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rdrand eax
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jnc .loop0
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call print_int
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.loop1:
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rdrand eax
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jnc .loop1
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call print_int
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EXIT
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