63 lines
2.0 KiB
C++
63 lines
2.0 KiB
C++
/* Copyright (C) 2021 William Welna (wwelna@occultusterra.com)
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "headers.hpp"
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RC4::RC4(char *seed, int len) {
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unsigned int x, y;
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for(x=0; x < 256; ++x)
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this->state[x] = x;
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for(x=0,y=0; y < 256; ++y)
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y = (y + this->state[x] + seed[x%len]) & 0xff;
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this->x = 0;
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this->y = 0;
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// Do an initial scramble
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for(x=0; x < 1024; ++x)
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this->rand8();
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}
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unsigned char RC4::rand8() {
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unsigned int t;
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this->x = (this->x + 1) & 0xff;
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this->y = (this->y + this->state[x]) & 0xff;
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t = this->x;
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this->x = this->y;
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this->y = t;
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return this->state[(this->state[this->x]+this->state[this->y]) & 0xff];
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}
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unsigned int RC4::rand() {
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return (this->rand8()<<8) + this->rand8();
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}
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char *init_rc4() {
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time_t t;
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int x;
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char *ret = (char *)calloc(SEEDSIZE, sizeof(char));
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srand((unsigned)time(&t));
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for(x=0; x < SEEDSIZE; ++x)
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*(ret+x) = (char)rand() & 0xff;
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return ret;
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}
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