cypher.cxx

mgcp协议源代码。支持多种编码：g711

}


void PMessageDigest5::Encode(const void * data, PINDEX len, Code & result)
{
  PMessageDigest5 stomach;
  stomach.Process(data, len);
  stomach.Complete(result);
}



///////////////////////////////////////////////////////////////////////////////
// PCypher

PCypher::PCypher(PINDEX blkSize, BlockChainMode mode)
  : blockSize(blkSize),
    chainMode(mode)
{
}


PCypher::PCypher(const void * keyData, PINDEX keyLength,
                 PINDEX blkSize, BlockChainMode mode)
  : key((const BYTE *)keyData, keyLength),
    blockSize(blkSize),
    chainMode(mode)
{
}


PString PCypher::Encode(const PString & str)
{
  return Encode((const char *)str, str.GetLength());
}


PString PCypher::Encode(const PBYTEArray & clear)
{
  return Encode((const BYTE *)clear, clear.GetSize());
}


PString PCypher::Encode(const void * data, PINDEX length)
{
  PBYTEArray coded;
  Encode(data, length, coded);
  return PBase64::Encode(coded);
}


void PCypher::Encode(const PBYTEArray & clear, PBYTEArray & coded)
{
  Encode((const BYTE *)clear, clear.GetSize(), coded);
}


void PCypher::Encode(const void * data, PINDEX length, PBYTEArray & coded)
{
  PAssert((blockSize%8) == 0, PUnsupportedFeature);

  Initialise(TRUE);

  const BYTE * in = (const BYTE *)data;
  BYTE * out = coded.GetPointer(
                      blockSize > 1 ? (length/blockSize+1)*blockSize : length);

  while (length >= blockSize) {
    EncodeBlock(in, out);
    in += blockSize;
    out += blockSize;
    length -= blockSize;
  }

  if (blockSize > 1) {
    PBYTEArray extra(blockSize);
    extra[blockSize-1] = (BYTE)length;
    for (PINDEX i = 0; i < length; i++)
      extra[i] = *in++;
    EncodeBlock(extra, out);
  }
}


PString PCypher::Decode(const PString & cypher)
{
  PString clear;
  if (Decode(cypher, clear))
    return clear;
  return PString();
}


BOOL PCypher::Decode(const PString & cypher, PString & clear)
{
  clear = PString();

  PBYTEArray clearText;
  if (!Decode(cypher, clearText))
    return FALSE;

  if (clearText.IsEmpty())
    return TRUE;

  PINDEX sz = clearText.GetSize();
  memcpy(clear.GetPointer(sz+1), (const BYTE *)clearText, sz);
  return TRUE;
}


BOOL PCypher::Decode(const PString & cypher, PBYTEArray & clear)
{
  PBYTEArray coded;
  if (!PBase64::Decode(cypher, coded))
    return FALSE;
  return Decode(coded, clear);
}


PINDEX PCypher::Decode(const PString & cypher, void * data, PINDEX length)
{
  PBYTEArray coded;
  PBase64::Decode(cypher, coded);
  PBYTEArray clear;
  if (!Decode(coded, clear))
    return 0;
  memcpy(data, clear, PMIN(length, clear.GetSize()));
  return clear.GetSize();
}


PINDEX PCypher::Decode(const PBYTEArray & coded, void * data, PINDEX length)
{
  PBYTEArray clear;
  if (!Decode(coded, clear))
    return 0;
  memcpy(data, coded, PMIN(length, clear.GetSize()));
  return clear.GetSize();
}


BOOL PCypher::Decode(const PBYTEArray & coded, PBYTEArray & clear)
{
  PAssert((blockSize%8) == 0, PUnsupportedFeature);
  if (coded.IsEmpty() || (coded.GetSize()%blockSize) != 0)
    return FALSE;

  Initialise(FALSE);

  const BYTE * in = coded;
  PINDEX length = coded.GetSize();
  BYTE * out = clear.GetPointer(length);

  for (PINDEX count = 0; count < length; count += blockSize) {
    DecodeBlock(in, out);
    in += blockSize;
    out += blockSize;
  }

  if (blockSize != 1) {
    if (*--out >= blockSize)
      return FALSE;
    clear.SetSize(length - blockSize + *out);
  }

  return TRUE;
}



///////////////////////////////////////////////////////////////////////////////
// PTEACypher

PTEACypher::PTEACypher(BlockChainMode chainMode)
  : PCypher(8, chainMode)
{
  GenerateKey(*(Key*)key.GetPointer(sizeof(Key)));
}


PTEACypher::PTEACypher(const Key & keyData, BlockChainMode chainMode)
  : PCypher(&keyData, sizeof(Key), 8, chainMode)
{
}


void PTEACypher::SetKey(const Key & newKey)
{
  memcpy(key.GetPointer(sizeof(Key)), &newKey, sizeof(Key));
}


void PTEACypher::GetKey(Key & newKey) const
{
  memcpy(&newKey, key, sizeof(Key));
}


void PTEACypher::GenerateKey(Key & newKey)
{
  static PRandom rand; //=1 // Explicitly set seed if need known random sequence
  for (PINDEX i = 0; i < sizeof(Key); i++)
    newKey.value[i] = (BYTE)rand;
}


static const DWORD TEADelta = 0x9e3779b9;    // Magic number for key schedule

void PTEACypher::Initialise(BOOL)
{
  k0 = ((const PUInt32l *)(const BYTE *)key)[0];
  k1 = ((const PUInt32l *)(const BYTE *)key)[1];
  k2 = ((const PUInt32l *)(const BYTE *)key)[2];
  k3 = ((const PUInt32l *)(const BYTE *)key)[3];
}


void PTEACypher::EncodeBlock(const void * in, void * out)
{
  DWORD y = ((PUInt32b*)in)[0];
  DWORD z = ((PUInt32b*)in)[1];
  DWORD sum = 0;
  for (PINDEX count = 32; count > 0; count--) {
    sum += TEADelta;    // Magic number for key schedule
    y += (z<<4)+k0 ^ z+sum ^ (z>>5)+k1;
    z += (y<<4)+k2 ^ y+sum ^ (y>>5)+k3;   /* end cycle */
  }
  ((PUInt32b*)out)[0] = y;
  ((PUInt32b*)out)[1] = z;
}


void PTEACypher::DecodeBlock(const void * in, void * out)
{
  DWORD y = ((PUInt32b*)in)[0];
  DWORD z = ((PUInt32b*)in)[1];
  DWORD sum = TEADelta<<5;
  for (PINDEX count = 32; count > 0; count--) {
    z -= (y<<4)+k2 ^ y+sum ^ (y>>5)+k3; 
    y -= (z<<4)+k0 ^ z+sum ^ (z>>5)+k1;
    sum -= TEADelta;    // Magic number for key schedule
  }
  ((PUInt32b*)out)[0] = y;
  ((PUInt32b*)out)[1] = z;
}


///////////////////////////////////////////////////////////////////////////////
// PSecureConfig

static const char DefaultSecuredOptions[] = "Secured Options";
static const char DefaultSecurityKey[] = "Validation";
static const char DefaultExpiryDateKey[] = "Expiry Date";
static const char DefaultOptionBitsKey[] = "Option Bits";
static const char DefaultPendingPrefix[] = "Pending:";

PSecureConfig::PSecureConfig(const PTEACypher::Key & prodKey,
                             const PStringArray & secKeys,
                             Source src)
  : PConfig(DefaultSecuredOptions, src),
    securedKeys(secKeys),
    securityKey(DefaultSecurityKey),
    expiryDateKey(DefaultExpiryDateKey),
    optionBitsKey(DefaultOptionBitsKey),
    pendingPrefix(DefaultPendingPrefix)
{
  productKey = prodKey;
}


PSecureConfig::PSecureConfig(const PTEACypher::Key & prodKey,
                             const char * const * secKeys,
                             PINDEX count,
                             Source src)
  : PConfig(DefaultSecuredOptions, src),
    securedKeys(count, secKeys),
    securityKey(DefaultSecurityKey),
    expiryDateKey(DefaultExpiryDateKey),
    optionBitsKey(DefaultOptionBitsKey),
    pendingPrefix(DefaultPendingPrefix)
{
  productKey = prodKey;
}


void PSecureConfig::GetProductKey(PTEACypher::Key & prodKey) const
{
  prodKey = productKey;
}


PSecureConfig::ValidationState PSecureConfig::GetValidation() const
{
  PString str;
  BOOL allEmpty = TRUE;
  PMessageDigest5 digestor;
  for (PINDEX i = 0; i < securedKeys.GetSize(); i++) {
    str = GetString(securedKeys[i]);
    if (!str.IsEmpty()) {
      digestor.Process(str.Trim());
      allEmpty = FALSE;
    }
  }
  str = GetString(expiryDateKey);
  if (!str.IsEmpty()) {
    digestor.Process(str);
    allEmpty = FALSE;
  }
  str = GetString(optionBitsKey);
  if (!str.IsEmpty()) {
    digestor.Process(str);
    allEmpty = FALSE;
  }

  PString vkey = GetString(securityKey);
  if (allEmpty)
    return (!vkey || GetBoolean(pendingPrefix + securityKey)) ? Pending : Defaults;

  PMessageDigest5::Code code;
  digestor.Complete(code);

  if (vkey.IsEmpty())
    return Invalid;

  BYTE info[sizeof(code)+1+sizeof(DWORD)];
  PTEACypher crypt(productKey);
  if (crypt.Decode(vkey, info, sizeof(info)) != sizeof(info))
    return Invalid;

  if (memcmp(info, &code, sizeof(code)) != 0)
    return Invalid;

  PTime now;
  if (now > GetTime(expiryDateKey))
    return Expired;

  return IsValid;
}


BOOL PSecureConfig::ValidatePending()
{
  if (GetValidation() != Pending)
    return FALSE;

  PString vkey = GetString(securityKey);
  if (vkey.IsEmpty())
    return TRUE;

  PMessageDigest5::Code code;
  BYTE info[sizeof(code)+1+sizeof(DWORD)];
  PTEACypher crypt(productKey);
  if (crypt.Decode(vkey, info, sizeof(info)) != sizeof(info))
    return FALSE;

  PTime expiryDate(0, 0, 0,
            1, info[sizeof(code)]&15, (info[sizeof(code)]>>4)+1996, PTime::GMT);
  PString expiry = expiryDate.AsString("d MMME yyyy", PTime::GMT);

  // This is for alignment problems on processors that care about such things
  PUInt32b opt;
  void * dst = &opt;
  void * src = &info[sizeof(code)+1];
  memcpy(dst, src, sizeof(opt));
  PString options(PString::Unsigned, (DWORD)opt);

  PMessageDigest5 digestor;
  PINDEX i;
  for (i = 0; i < securedKeys.GetSize(); i++)
    digestor.Process(GetString(pendingPrefix + securedKeys[i]).Trim());
  digestor.Process(expiry);
  digestor.Process(options);
  digestor.Complete(code);

  if (memcmp(info, &code, sizeof(code)) != 0)
    return FALSE;

  SetString(expiryDateKey, expiry);
  SetString(optionBitsKey, options);

  for (i = 0; i < securedKeys.GetSize(); i++) {
    PString str = GetString(pendingPrefix + securedKeys[i]);
    if (!str.IsEmpty())
      SetString(securedKeys[i], str);
    DeleteKey(pendingPrefix + securedKeys[i]);
  }
  DeleteKey(pendingPrefix + securityKey);

  return TRUE;
}


void PSecureConfig::ResetPending()
{
  if (GetBoolean(pendingPrefix + securityKey)) {
    for (PINDEX i = 0; i < securedKeys.GetSize(); i++)
      DeleteKey(securedKeys[i]);
  }
  else {
    SetBoolean(pendingPrefix + securityKey, TRUE);

    for (PINDEX i = 0; i < securedKeys.GetSize(); i++) {
      PString str = GetString(securedKeys[i]);
      if (!str.IsEmpty())
        SetString(pendingPrefix + securedKeys[i], str);
      DeleteKey(securedKeys[i]);
    }
  }
  DeleteKey(expiryDateKey);
  DeleteKey(optionBitsKey);
}


///////////////////////////////////////////////////////////////////////////////