41 lines
1.5 KiB
C
41 lines
1.5 KiB
C
/*
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* Copyright (c) 2023 Stephen Heumann
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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struct rc4_context {
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unsigned char i,j;
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unsigned char S[256];
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};
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/*
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* Initialize an RC4 context context with a specified key.
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* This must be called before calling rc4_process.
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*/
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void rc4_init(struct rc4_context *context,
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const unsigned char *key,
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unsigned keylength);
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/*
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* Process data using RC4. This either encrypts or decrypts data,
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* depending on whether in contains plaintext or ciphertext.
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*
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* To get the raw RC4 output stream, specify the input as all zeros.
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* The same buffer may be used for in and out.
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*/
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void rc4_process(struct rc4_context *context,
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const unsigned char *in,
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unsigned char *out,
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unsigned long length);
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