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https://github.com/radareorg/radare2.git
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f2563a7509
- Handled by 'S' command * Added dummy 'z' command to handle zignaturez - Added more dummy 'az' commands - RCore now depends on RSign * Some refactoring and speedup in _update method of RSearch - Added support for distance search (maybe buggy and incomplete atm) - Fix binary mask for keywords after previous commit * Added 'r_str_rwx*' helper functions in r_util
32 lines
781 B
C
32 lines
781 B
C
/*
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* This code was done
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* by an anonymous gnome
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* ------------------------
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* That's pure mathematics, so no sense to adding license shit here.
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*/
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#include <stdlib.h>
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#include <math.h>
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#include "r_types.h"
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static double get_px(ut8 x, const ut8 *data, ut64 size) {
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ut32 i, count = 0;
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for (i = 0; i < size; i++)
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if (data[i] == x)
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count++;
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return (double)count/size;
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}
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R_API double r_hash_entropy(const ut8 *data, ut64 size) {
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double h = 0, px, log2;
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unsigned char x;
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log2 = logf ((double)2);
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for (x = 0; x < 255; x++) {
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px = get_px (x, data, size);
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if (px > 0)
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h += -px * (log (px)/log2);
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}
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return h;
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}
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