/* md2.c
 *
 * Copyright (C) 2006-2015 wolfSSL Inc.
 *
 * This file is part of wolfSSL. (formerly known as CyaSSL)
 *
 * wolfSSL is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * wolfSSL is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 */


#ifdef HAVE_CONFIG_H
    #include <config.h>
#endif

#include <wolfssl/wolfcrypt/settings.h>

#ifdef WOLFSSL_MD2

#include <wolfssl/wolfcrypt/md2.h>
#include <wolfssl/wolfcrypt/error-crypt.h>

#ifdef NO_INLINE
    #include <wolfssl/wolfcrypt/misc.h>
#else
    #include <wolfcrypt/src/misc.c>
#endif


void wc_InitMd2(Md2* md2)
{
    XMEMSET(md2->X, 0, MD2_X_SIZE);
    XMEMSET(md2->C, 0, MD2_BLOCK_SIZE);
    XMEMSET(md2->buffer, 0, MD2_BLOCK_SIZE);
    md2->count = 0;
}


void wc_Md2Update(Md2* md2, const byte* data, word32 len)
{
    static const byte S[256] = 
    {
        41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
        19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
        76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
        138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
        245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
        148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
        39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
        181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
        150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
        112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
        96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
        85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
        234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
        129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
        8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
        203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
        166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
        31, 26, 219, 153, 141, 51, 159, 17, 131, 20
    };

    while (len) {
        word32 L = (MD2_PAD_SIZE - md2->count) < len ?
                   (MD2_PAD_SIZE - md2->count) : len;
        XMEMCPY(md2->buffer + md2->count, data, L);
        md2->count += L;
        data += L;
        len  -= L;

        if (md2->count == MD2_PAD_SIZE) {
            int  i;
            byte t;

            md2->count = 0;
            XMEMCPY(md2->X + MD2_PAD_SIZE, md2->buffer, MD2_PAD_SIZE);
            t = md2->C[15];

            for(i = 0; i < MD2_PAD_SIZE; i++) {
                md2->X[32 + i] = md2->X[MD2_PAD_SIZE + i] ^ md2->X[i];
                t = md2->C[i] ^= S[md2->buffer[i] ^ t];
            }

            t=0;
            for(i = 0; i < 18; i++) {
                int j;
                for(j = 0; j < MD2_X_SIZE; j += 8) {
                    t = md2->X[j+0] ^= S[t];
                    t = md2->X[j+1] ^= S[t];
                    t = md2->X[j+2] ^= S[t];
                    t = md2->X[j+3] ^= S[t];
                    t = md2->X[j+4] ^= S[t];
                    t = md2->X[j+5] ^= S[t];
                    t = md2->X[j+6] ^= S[t];
                    t = md2->X[j+7] ^= S[t];
                }
                t = (t + i) & 0xFF;
            }
        }
    }
}


void wc_Md2Final(Md2* md2, byte* hash)
{
    byte   padding[MD2_BLOCK_SIZE];
    word32 padLen = MD2_PAD_SIZE - md2->count;
    word32 i;

    for (i = 0; i < padLen; i++)
        padding[i] = (byte)padLen;

    wc_Md2Update(md2, padding, padLen);
    wc_Md2Update(md2, md2->C, MD2_BLOCK_SIZE);

    XMEMCPY(hash, md2->X, MD2_DIGEST_SIZE);

    wc_InitMd2(md2);
}


int wc_Md2Hash(const byte* data, word32 len, byte* hash)
{
#ifdef WOLFSSL_SMALL_STACK
    Md2* md2;
#else
    Md2 md2[1];
#endif

#ifdef WOLFSSL_SMALL_STACK
    md2 = (Md2*)XMALLOC(sizeof(Md2), NULL, DYNAMIC_TYPE_TMP_BUFFER);
    if (md2 == NULL)
        return MEMORY_E;
#endif

    wc_InitMd2(md2);
    wc_Md2Update(md2, data, len);
    wc_Md2Final(md2, hash);

#ifdef WOLFSSL_SMALL_STACK
    XFREE(md2, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif

    return 0;
}


#endif /* WOLFSSL_MD2 */