/*
 * Copyright 2006 Kai Blin
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 *
 * This file contains various helper functions needed for NTLM and maybe others
 */
#include <stdarg.h>
#include <stdio.h>
#include "windef.h"
#include "winbase.h"
#include "rpc.h"
#include "sspi.h"
#include "secur32_priv.h"
#include "wine/debug.h"

WINE_DEFAULT_DEBUG_CHANNEL(ntlm);

/* The CRC32 code is copyright (C) 1986 Gary S. Brown and was placed in the
 * public domain.
 * CRC polynomial 0xedb88320
 */
static const ULONG CRC_table[256] =
{
    0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
    0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
    0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
    0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
    0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
    0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
    0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
    0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
    0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
    0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
    0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
    0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
    0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
    0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
    0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
    0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
    0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
    0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
    0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
    0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
    0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
    0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
    0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
    0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
    0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
    0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
    0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
    0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
    0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
    0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
    0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
    0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
    0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
    0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
    0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
    0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
    0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
    0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
    0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
    0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
    0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
    0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
    0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
};

static const char client_to_server_sign_constant[] = "session key to client-to-server signing key magic constant";
static const char client_to_server_seal_constant[] = "session key to client-to-server sealing key magic constant";
static const char server_to_client_sign_constant[] = "session key to server-to-client signing key magic constant";
static const char server_to_client_seal_constant[] = "session key to server-to-client sealing key magic constant";

typedef struct
{
    unsigned int buf[4];
    unsigned int i[2];
    unsigned char in[64];
    unsigned char digest[16];
} MD4_CTX;

/* And now the same with a different memory layout. */
typedef struct
{
    unsigned int i[2];
    unsigned int buf[4];
    unsigned char in[64];
    unsigned char digest[16];
} MD5_CTX;

VOID WINAPI MD4Init( MD4_CTX *ctx );
VOID WINAPI MD4Update( MD4_CTX *ctx, const unsigned char *buf, unsigned int len );
VOID WINAPI MD4Final( MD4_CTX *ctx );
VOID WINAPI MD5Init( MD5_CTX *ctx );
VOID WINAPI MD5Update( MD5_CTX *ctx, const unsigned char *buf, unsigned int len );
VOID WINAPI MD5Final( MD5_CTX *ctx );

ULONG ComputeCrc32(const BYTE *pData, INT iLen, ULONG initial_crc)
{
  ULONG crc = ~initial_crc;

  while (iLen > 0)
  {
    crc = CRC_table[(crc ^ *pData) & 0xff] ^ (crc >> 8);
    pData++;
    iLen--;
  }
  return ~crc;
}

SECURITY_STATUS SECUR32_CreateNTLMv1SessionKey(PBYTE password, int len, PBYTE session_key)
{
    MD4_CTX ctx;
    BYTE ntlm_hash[16];

    TRACE("(%p, %p)\n", password, session_key);

    MD4Init(&ctx);
    MD4Update(&ctx, (const unsigned char*) password, len);
    MD4Final(&ctx);

    memcpy(ntlm_hash, ctx.digest, 0x10);

    MD4Init(&ctx);
    MD4Update(&ctx, ntlm_hash, 0x10u);
    MD4Final(&ctx);

    memcpy(session_key, ctx.digest, 0x10);

    return SEC_E_OK;
}

static void SECUR32_CalcNTLMv2Subkey(const BYTE *session_key, const char *magic, PBYTE subkey)
{
    MD5_CTX ctx;

    MD5Init(&ctx);
    MD5Update(&ctx, session_key, 16);
    MD5Update(&ctx, (const unsigned char*)magic, lstrlenA(magic)+1);
    MD5Final(&ctx);
    memcpy(subkey, ctx.digest, 16);
}

/* This assumes we do have a valid NTLM2 user session key */
SECURITY_STATUS SECUR32_CreateNTLMv2SubKeys(PNegoHelper helper)
{
    helper->crypt.ntlm2.send_sign_key = HeapAlloc(GetProcessHeap(), 0, 16);
    helper->crypt.ntlm2.send_seal_key = HeapAlloc(GetProcessHeap(), 0, 16);
    helper->crypt.ntlm2.recv_sign_key = HeapAlloc(GetProcessHeap(), 0, 16);
    helper->crypt.ntlm2.recv_seal_key = HeapAlloc(GetProcessHeap(), 0, 16);

    if(helper->mode == NTLM_CLIENT)
    {
        SECUR32_CalcNTLMv2Subkey(helper->session_key, client_to_server_sign_constant,
                helper->crypt.ntlm2.send_sign_key);
        SECUR32_CalcNTLMv2Subkey(helper->session_key, client_to_server_seal_constant,
                helper->crypt.ntlm2.send_seal_key);
        SECUR32_CalcNTLMv2Subkey(helper->session_key, server_to_client_sign_constant,
                helper->crypt.ntlm2.recv_sign_key);
        SECUR32_CalcNTLMv2Subkey(helper->session_key, server_to_client_seal_constant,
                helper->crypt.ntlm2.recv_seal_key);
    }
    else
    {
        SECUR32_CalcNTLMv2Subkey(helper->session_key, server_to_client_sign_constant,
                helper->crypt.ntlm2.send_sign_key);
        SECUR32_CalcNTLMv2Subkey(helper->session_key, server_to_client_seal_constant,
                helper->crypt.ntlm2.send_seal_key);
        SECUR32_CalcNTLMv2Subkey(helper->session_key, client_to_server_sign_constant,
                helper->crypt.ntlm2.recv_sign_key);
        SECUR32_CalcNTLMv2Subkey(helper->session_key, client_to_server_seal_constant,
                helper->crypt.ntlm2.recv_seal_key);
    }

    return SEC_E_OK;
}

arc4_info *SECUR32_arc4Alloc(void)
{
    arc4_info *a4i = HeapAlloc(GetProcessHeap(), 0, sizeof(arc4_info));
    return a4i;
}

/*
 * The arc4 code is based on dlls/advapi32/crypt_arc4.c by Mike McCormack,
 * which in turn is based on public domain code by Wei Dai
 */
void SECUR32_arc4Init(arc4_info *a4i, const BYTE *key, unsigned int keyLen)
{
    unsigned int keyIndex = 0, stateIndex = 0;
    unsigned int i, a;

    TRACE("(%p, %p, %d)\n", a4i, key, keyLen);

        a4i->x = a4i->y = 0;

    for (i=0; i<256; i++)
        a4i->state[i] = i;

    for (i=0; i<256; i++)
    {
        a = a4i->state[i];
        stateIndex += key[keyIndex] + a;
        stateIndex &= 0xff;
        a4i->state[i] = a4i->state[stateIndex];
        a4i->state[stateIndex] = a;
        if (++keyIndex >= keyLen)
            keyIndex = 0;
    }

}

void SECUR32_arc4Process(arc4_info *a4i, BYTE *inoutString, unsigned int length)
{
    BYTE *const s=a4i->state;
    unsigned int x = a4i->x;
    unsigned int y = a4i->y;
    unsigned int a, b;

    while(length--)
    {
        x = (x+1) & 0xff;
        a = s[x];
        y = (y+a) & 0xff;
        b = s[y];
        s[x] = b;
        s[y] = a;
        *inoutString++ ^= s[(a+b) & 0xff];
    }

    a4i->x = x;
    a4i->y = y;
}

void SECUR32_arc4Cleanup(arc4_info *a4i)
{
    HeapFree(GetProcessHeap(), 0, a4i);
}