49 lines
1010 B
C
49 lines
1010 B
C
// Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) All rights reserved.
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// SPDX-License-Identifier: Apache-2.0
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#include <openssl/rc4.h>
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const char *RC4_options(void) {
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return "rc4(ptr,int)";
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}
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void RC4(RC4_KEY *key, size_t len, const uint8_t *in, uint8_t *out) {
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uint32_t x = key->x;
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uint32_t y = key->y;
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uint32_t *d = key->data;
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for (size_t i = 0; i < len; i++) {
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x = (x + 1) & 0xff;
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uint32_t tx = d[x];
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y = (tx + y) & 0xff;
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uint32_t ty = d[y];
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d[x] = ty;
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d[y] = tx;
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out[i] = d[(tx + ty) & 0xff] ^ in[i];
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}
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key->x = x;
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key->y = y;
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}
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void RC4_set_key(RC4_KEY *rc4key, unsigned len, const uint8_t *key) {
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uint32_t *d = &rc4key->data[0];
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rc4key->x = 0;
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rc4key->y = 0;
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for (unsigned i = 0; i < 256; i++) {
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d[i] = i;
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}
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unsigned id1 = 0, id2 = 0;
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for (unsigned i = 0; i < 256; i++) {
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uint32_t tmp = d[i];
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id2 = (key[id1] + tmp + id2) & 0xff;
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if (++id1 == len) {
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id1 = 0;
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}
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d[i] = d[id2];
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d[id2] = tmp;
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}
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}
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