/*
 * Copyright 1995-2026 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

/*
 * RC2 low level APIs are deprecated for public use, but still ok for internal
 * use.
 */
#include "internal/deprecated.h"

#include <openssl/rc2.h>
#include "rc2_local.h"

static const unsigned char key_table[256] = {
    0xd9, 0x78, 0xf9, 0xc4, 0x19, 0xdd, 0xb5, 0xed, 0x28, 0xe9,
    0xfd, 0x79, 0x4a, 0xa0, 0xd8, 0x9d, 0xc6, 0x7e, 0x37, 0x83,
    0x2b, 0x76, 0x53, 0x8e, 0x62, 0x4c, 0x64, 0x88, 0x44, 0x8b,
    0xfb, 0xa2, 0x17, 0x9a, 0x59, 0xf5, 0x87, 0xb3, 0x4f, 0x13,
    0x61, 0x45, 0x6d, 0x8d, 0x09, 0x81, 0x7d, 0x32, 0xbd, 0x8f,
    0x40, 0xeb, 0x86, 0xb7, 0x7b, 0x0b, 0xf0, 0x95, 0x21, 0x22,
    0x5c, 0x6b, 0x4e, 0x82, 0x54, 0xd6, 0x65, 0x93, 0xce, 0x60,
    0xb2, 0x1c, 0x73, 0x56, 0xc0, 0x14, 0xa7, 0x8c, 0xf1, 0xdc,
    0x12, 0x75, 0xca, 0x1f, 0x3b, 0xbe, 0xe4, 0xd1, 0x42, 0x3d,
    0xd4, 0x30, 0xa3, 0x3c, 0xb6, 0x26, 0x6f, 0xbf, 0x0e, 0xda,
    0x46, 0x69, 0x07, 0x57, 0x27, 0xf2, 0x1d, 0x9b, 0xbc, 0x94,
    0x43, 0x03, 0xf8, 0x11, 0xc7, 0xf6, 0x90, 0xef, 0x3e, 0xe7,
    0x06, 0xc3, 0xd5, 0x2f, 0xc8, 0x66, 0x1e, 0xd7, 0x08, 0xe8,
    0xea, 0xde, 0x80, 0x52, 0xee, 0xf7, 0x84, 0xaa, 0x72, 0xac,
    0x35, 0x4d, 0x6a, 0x2a, 0x96, 0x1a, 0xd2, 0x71, 0x5a, 0x15,
    0x49, 0x74, 0x4b, 0x9f, 0xd0, 0x5e, 0x04, 0x18, 0xa4, 0xec,
    0xc2, 0xe0, 0x41, 0x6e, 0x0f, 0x51, 0xcb, 0xcc, 0x24, 0x91,
    0xaf, 0x50, 0xa1, 0xf4, 0x70, 0x39, 0x99, 0x7c, 0x3a, 0x85,
    0x23, 0xb8, 0xb4, 0x7a, 0xfc, 0x02, 0x36, 0x5b, 0x25, 0x55,
    0x97, 0x31, 0x2d, 0x5d, 0xfa, 0x98, 0xe3, 0x8a, 0x92, 0xae,
    0x05, 0xdf, 0x29, 0x10, 0x67, 0x6c, 0xba, 0xc9, 0xd3, 0x00,
    0xe6, 0xcf, 0xe1, 0x9e, 0xa8, 0x2c, 0x63, 0x16, 0x01, 0x3f,
    0x58, 0xe2, 0x89, 0xa9, 0x0d, 0x38, 0x34, 0x1b, 0xab, 0x33,
    0xff, 0xb0, 0xbb, 0x48, 0x0c, 0x5f, 0xb9, 0xb1, 0xcd, 0x2e,
    0xc5, 0xf3, 0xdb, 0x47, 0xe5, 0xa5, 0x9c, 0x77, 0x0a, 0xa6,
    0x20, 0x68, 0xfe, 0x7f, 0xc1, 0xad
};

#if defined(_MSC_VER) && defined(_ARM_)
#pragma optimize("g", off)
#endif

/*
 * It has come to my attention that there are 2 versions of the RC2 key
 * schedule.  One which is normal, and another which has a hook to use a
 * reduced key length. BSAFE uses the latter version.  What I previously
 * shipped is the same as specifying 1024 for the 'bits' parameter.  Bsafe
 * uses a version where the bits parameter is the same as len*8
 */
void RC2_set_key(RC2_KEY *key, int len, const unsigned char *data, int bits)
{
    int i, j;
    unsigned char *k;
    RC2_INT *ki;
    unsigned int c, d;

    k = (unsigned char *)&(key->data[0]);
    *k = 0; /* for if there is a zero length key */

    if (len > 128)
        len = 128;
    if (bits <= 0)
        bits = 1024;
    if (bits > 1024)
        bits = 1024;

    for (i = 0; i < len; i++)
        k[i] = data[i];

    /* expand table */
    d = k[len - 1];
    j = 0;
    for (i = len; i < 128; i++, j++) {
        d = key_table[(k[j] + d) & 0xff];
        k[i] = d;
    }

    /* hmm.... key reduction to 'bits' bits */

    j = (bits + 7) >> 3;
    i = 128 - j;
    c = (0xff >> (-bits & 0x07));

    d = key_table[k[i] & c];
    k[i] = d;
    while (i--) {
        d = key_table[k[i + j] ^ d];
        k[i] = d;
    }

    /* copy from bytes into RC2_INT's */
    ki = &(key->data[63]);
    for (i = 127; i >= 0; i -= 2)
        *(ki--) = ((k[i] << 8) | k[i - 1]) & 0xffff;
}

#if defined(_MSC_VER)
#pragma optimize("", on)
#endif
