63 lines
1.5 KiB
C++
63 lines
1.5 KiB
C++
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#include "stdafx.h"
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#include "qRC4.h"
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#include <QByteArray>
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void
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rc4_swap(unsigned char &a, unsigned char &b)
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{
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unsigned char c = a;
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a = b;
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b = c;
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}
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void
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rc4_init(rc4_sbox_t *rc4_sbox, const unsigned char *key_ptr, unsigned int key_len)
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{
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rc4_sbox->x = 0;
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rc4_sbox->y = 0;
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// Initialisation of the permutation
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unsigned int i;
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for (i = 0; i < 256; i++)
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rc4_sbox->state[i] = (char)i;
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// Mixing permutation
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unsigned int j = 0;
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unsigned int k;
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for (i = 0; i < 256; i++)
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{
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k = i % key_len;
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j = (key_ptr[k] + rc4_sbox->state[i] + j) & 0xff;
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rc4_swap(rc4_sbox->state[i], rc4_sbox->state[j]);
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}
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}
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void
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rc4_transform(rc4_sbox_t *rc4_sbox, unsigned char *buffer_ptr, unsigned int buffer_len)
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{
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unsigned int i;
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for (i = 0; i < buffer_len; i++)
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{
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// The pseudo-random generation algorithm
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rc4_sbox->x = (rc4_sbox->x + 1) & 0xff;
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rc4_sbox->y = (rc4_sbox->y + rc4_sbox->state[rc4_sbox->x]) & 0xff;
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rc4_swap(rc4_sbox->state[rc4_sbox->x], rc4_sbox->state[rc4_sbox->y]);
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unsigned char keyChar = rc4_sbox->state[(rc4_sbox->state[rc4_sbox->x] + rc4_sbox->state[rc4_sbox->y]) & 0xff];
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if (buffer_ptr) // NULL when seeking
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buffer_ptr[i] ^= keyChar;
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}
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}
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void MISCHELPERS_EXPORT rc4_init(rc4_sbox_t *rc4_sbox, const QByteArray& Key)
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{
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rc4_init(rc4_sbox, (unsigned char*)Key.data(), Key.size());
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}
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QByteArray MISCHELPERS_EXPORT rc4_transform(rc4_sbox_t *rc4_sbox, const QByteArray& Data)
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{
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QByteArray Temp = Data;
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rc4_transform(rc4_sbox, (unsigned char*)Temp.data(), Temp.size());
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return Temp;
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}
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