/** @file
  AT authetication module for using AT DXE driver.
  This driver uses the AT protocol, HECI Protocol and AT Platform Policy to implement Theft Deterrence Technology AM module.

@copyright
  Copyright (c) 2004 - 2012 Intel Corporation. All rights reserved
  This software and associated documentation (if any) is furnished
  under a license and may only be used or copied in accordance
  with the terms of the license. Except as permitted by such
  license, no part of this software or documentation may be
  reproduced, stored in a retrieval system, or transmitted in any
  form or by any means without the express written consent of
  Intel Corporation.

  This file contains an 'Intel Peripheral Driver' and uniquely
  identified as "Intel Reference Module" and is
  licensed for Intel CPUs and chipsets under the terms of your
  license agreement with Intel or your vendor.  This file may
  be modified by the user, subject to additional terms of the
  license agreement

**/

//
// External include files do NOT need to be explicitly specified in real EDKII
// environment
//

#include "AtAmHelper.h"

const CHAR8  *PEMCodes   = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-!=";
const CHAR8  *LineBreak  = " \n\t";

/**
  Convert Hex values into Base32 values

  @param[in] encodedStr           Array of encoded BASE values.
  @param[in] encodedLen           Length of encoded values.
  @param[out] rawData             Array of Hex strings that needs to be encoded into BASE32.
  @param[out] rawDataLen          Length of Hex values.

  @retval EFI_BUFFER_TOO_SMALL   Buffer to store encoded string too small.
  @retval EFI_SUCCESS            Initialization complete.
**/
EFI_STATUS
Base32Encode (
  IN UINT8                        *encodedStr,
  IN UINTN                        *encodedLen,
  OUT UINT8                       *rawData,
  OUT UINTN                       rawDataLen
  )
{
  UINTN i;
  UINTN j;
  UINT8 value;
  INTN  shift;
  INTN  shifttable[] = { 3, -2, 1, -4, -1, 2, -3, 0 };

  if (encodedLen && *encodedLen < (rawDataLen * 8) / 5) {
    DEBUG ((EFI_D_ERROR, "ATAm::Base32Encode:  Buffer to store encoded string too small"));
    return EFI_BUFFER_TOO_SMALL;
  }

  for (i = 0, j = 0; i < rawDataLen; j++) {
    shift = shifttable[j % 8];
    if (shift > 0) {
      value = (UINT8) (rawData[i] >> shift);
    } else {
      value = (UINT8) (rawData[i] << (-shift));
      if (i++ < rawDataLen - 1) {
        value |= (rawData[i] >> (8 + shift));
      }
    }

    value &= 0x1f;
    if (25 >= value) {
      value += 'A';
    } else {
      value += '2' - 26;
    }

    if (encodedStr && encodedLen) {
      encodedStr[j] = value;
    }
  }

  if (encodedStr && encodedLen) {
    *encodedLen   = j;
    encodedStr[j] = L'\0';
  }

  return EFI_SUCCESS;
}

/**
  Convert Base32 values into Hex values.

  @param[in] encodedStr           Array of Decimal numbers.
  @param[out] decodedData         Converted Hex values.

  @retval   Length of the Hex Strings that expected.
**/
INTN
Base32Decode (
  IN UINT8                        *encodedStr,
  IN UINT8                        *decodedData
  )
{
  UINTN i;
  UINTN j;
  INTN  retVal;
  UINT8 value;
  UINTN decodedLen;
  INTN  shifttable[] = { 3, -2, 1, -4, -1, 2, -3, 0 };
  INTN  shift;
  UINTN encodedLen;

  retVal          = 1;
  encodedLen      = AsciiStrLen ((char *) encodedStr);

  decodedLen      = (encodedLen * 5) / 8;

  decodedData[0]  = 0;
  for (i = 0, j = 0; i < encodedLen; i++) {
    if ('A' <= encodedStr[i] && 'Z' >= encodedStr[i]) {
      value = encodedStr[i] - 'A';
    } else if ('a' <= encodedStr[i] && 'z' >= encodedStr[i]) {
      value = encodedStr[i] - 'a';
    } else if ('2' <= encodedStr[i] && '7' >= encodedStr[i]) {
      value = encodedStr[i] - '2' + 26;
    } else {
      retVal = 0;
      break;
    }

    shift = shifttable[i % 8];
    if (shift > 0) {
      decodedData[j] |= (value << shift);
    } else {
      decodedData[j] |= (value >> (-shift));
      ///
      /// Pack the bits that are going to fall off due to right shift in next byte
      /// (left justfied) unless decoding the last character. In case of last
      /// character, the extra bits are just padding to make the length of input
      /// bits a multiple of 5 while encoding - so ignore them
      ///
      if (i != encodedLen - 1) {
        decodedData[++j] = (UINT8) (value << (8 + shift));
      }
    }
  }

  return retVal;
}

/**
  Decimal large (BASE10) into hex value.

  @param[in][out] decStr          Array of Decimal numbers.
  @param[out] u8Hex               Converted Hex values.
  @param[in] hexIndex             Length of the Hex Strings that expected

  @retval None
**/
VOID
DecimalToHexString (
  IN OUT CHAR8                    *decStr,
  OUT UINT8                       *u8Hex,
  IN UINTN                        hexIndex
  )
{

  UINTN i;
  UINTN j;
  UINTN Remainder;
  CHAR8 Quotient;
  UINTN num;
  UINTN len;
  UINTN leadingZero;

  leadingZero = 1;

  len         = AsciiStrLen ((CHAR8 *) decStr);
  Remainder   = decStr[0] - '0';

  if (len > 1) {
    Remainder = Remainder * 10 + decStr[1] - '0';
  }

  if (len < 3) {
    u8Hex[hexIndex] = (UINT8) Remainder;
    return;
  }

  i = 2;
  j = 0;
  while (i < len) {
    num       = Remainder * 10 + decStr[i] - '0';
    Quotient  = (CHAR8) (num / 256);
    if (!leadingZero || Quotient) {
      decStr[j++] = '0' + Quotient;
      leadingZero = 0;
    }

    Remainder = num % 256;
    i++;

  }

  decStr[j]         = L'\0';
  u8Hex[hexIndex--] = (UINT8) Remainder;

  if (decStr[0] != L'\0') {
    DecimalToHexString (decStr, u8Hex, hexIndex);
  }

  return;
}

/**
  Convert the CHAR8 ASCII into CHAR16 Unicode strings.

  @param[in] AsciiString          Ascii String.
  @param[out] UnicodeString Buffer for converted Unicode string.

  @retval None
**/
VOID
Uint8ToUnicode (
  IN  CHAR8                       *AsciiString,
  OUT CHAR16                      *UnicodeString
  )
{
  UINT8 Index;

  Index = 0;

  while (AsciiString[Index] != 0) {
    UnicodeString[Index] = (CHAR16) AsciiString[Index];
    Index++;
  }
}

/**
  Decode a PEM-encoded character.

  @param[in] pemChar              PEM-encoded character.

  @retval   Value orresponding to the character, or PEM_INVALID_CHARACTER if the input character could not be decoded.
**/
UINT8
DecodePEMChar (
  IN UINT8                        pemChar
  )
{
  if ((pemChar >= 'A') && (pemChar <= 'Z')) {
    return pemChar - 'A';
  }

  if ((pemChar >= 'a') && (pemChar <= 'z')) {
    return (pemChar - 'a') + 26;
  }

  if ((pemChar >= '0') && (pemChar <= '9')) {
    return (pemChar - '0') + 52;
  }

  if (pemChar == '-') {
    return 62;
  }

  if (pemChar == '!') {
    return 63;
  }

  if (pemChar == '=') {
    return PEM_PAD_CHAR;

  }

  DEBUG ((EFI_D_ERROR, "DecodePEMChar: Invalid  character %d\n", pemChar));
  return PEM_INVALID_CHAR;
}

/**
  Decode character in ASCII to hexadecimal

  @param[in] base16char           Character in ASCII

  @retval Value in hexadecimal.
**/
UINT8
DecodeBase16Char (
  IN UINT8                        base16char
  )
{
  if (base16char >= '0' && base16char <= '9') {
    return base16char - '0';
  } else if (base16char >= 'A' && base16char <= 'F') {
    return base16char - 'A' + 0xA;
  } else if (base16char >= 'a' && base16char <= 'f') {
    return base16char - 'a' + 0xA;
  }

  return 0;
}

/**
  Decode ASCII string to hexadecimal string

  @param[in] pString              Pointer of ASCII string
  @param[in] stringLen            Size of the ASCII string
  @param[out] pDecodedData        Pointer of hexadecimal string
  @param[out] pBufLength          Pointer to buffer length returned

  @retval FALSE                   Failed to decode the string by invalid length or buffer size
  @retval TRUE                    The hexadecimal string returned
**/
BOOLEAN
Base16Decode (
  IN UINT8                        *pString,
  IN UINT32                       stringLen,
  OUT UINT8                       *pDecodedData,
  OUT UINT32                      *pBufLength
  )
{
  UINT32 i;
  if (stringLen % 2 != 0) {
    DEBUG ((EFI_D_ERROR, "Cannot decode hexadecimal string -- invalid length\n"));
  } else if (*pBufLength < stringLen / 2) {
    DEBUG ((EFI_D_ERROR, "Base16 decode - output buffer too small\n"));
  } else {
    for (i = 0; i < (UINT32) stringLen / 2; i++) {
      pDecodedData[i] = DecodeBase16Char (pString[2 * i]) << 4;
      pDecodedData[i] |= DecodeBase16Char (pString[2 * i + 1]);
    }

    *pBufLength = i;
    return TRUE;
  }

  return FALSE;
}

/**
  Encode string to ASCII code

  @param[in] pData                Pointer of string to be encoded
  @param[in] dataLength           Size of the string to be
  @param[out] pEncodedData        Pointer of encoded string
  @param[out] pBufLength          Pointer to buffer length returned

  @retval FALSE                   Failed to encode the string by invalid length or buffer size
  @retval TRUE                    The encoded string returned
**/
BOOLEAN
Base16Encode (
  IN UINT8                        *pData,
  IN UINT32                       dataLength,
  OUT UINT8                       *pEncodedData,
  OUT UINT32                      *pBufLength
  )
{
  UINT32  i;
  if (*pBufLength < 2 * dataLength) {
    DEBUG ((EFI_D_ERROR, "Cannot encode data -- output buffer too small\n"));
    return FALSE;
  }

  DEBUG ((EFI_D_ERROR, "Base16Encode dataLength : %d\n", dataLength));

  for (i = 0; i < dataLength; i++) {
    AsciiSPrint ((CHAR8 *) &pEncodedData[2 * i], 3 * sizeof (UINT8), "%02x", pData[i] & 0xFF);
  }

  DEBUG ((EFI_D_ERROR, "Base16Encode AsciiSPrint : %s\n", (char *) pEncodedData));
  DEBUG ((EFI_D_ERROR, "Base16Encode Sprint : %s\n", (char *) pEncodedData));

  *pBufLength = 2 * dataLength;

  return TRUE;
}

/**
  Decode PEM-Encoded data

  @param[in] pPEMString           Pointer to PEM-Encoded buffer
  @param[in] lineLength           Length in bytes
  @param[in] pDecodedData         Pointer to buffer to receive decoded bytes
  @param[in] pBufLength           Pointer to the size of the output buffer. Upon return this will
                                  contain the length of the decoded data

  @retval Returns status code indicating outcome of operation
**/
BOOLEAN
PEMSMSDecode (
  IN UINT8                        *pPEMString,
  IN UINT32                       lineLength,
  OUT UINT8                       *pDecodedData,
  OUT UINT32                      *pBufLength
  )
{
  UINT8   *pStr;
  UINT32  curOutLen;
  UINT8   *pOut;
  UINT32  i;
  UINT32  padBytes;
  UINT8   val1;
  UINT8   val2;
  UINT8   decodedValue[4];
  UINT32  ii;
  UINT32  unitCount;
  UINT32  decodedBytes;

  pStr      = pPEMString;
  curOutLen = *pBufLength;
  pOut      = pDecodedData;
  padBytes  = 0;

  if (pStr != NULL) {
    if ((lineLength % 4) != 0) {
      DEBUG ((EFI_D_ERROR, "Cannot decode PEM string -- invalid length -1\n"));
      return FALSE;
    }

    unitCount = lineLength / 4;

    for (i = 0; (i < unitCount) && (padBytes == 0); i++) {
      val1  = DecodePEMChar (*pStr++);
      val2  = DecodePEMChar (*pStr++);

      if ((val1 == PEM_INVALID_CHAR) || (val2 == PEM_INVALID_CHAR)) {
        DEBUG ((EFI_D_ERROR, "Cannot decode PEM string -- invalid character -2\n"));
        return FALSE;
      }

      decodedValue[0] = ((val1 << 2) | (val2 >> 4));
      val1            = DecodePEMChar (*pStr++);
      if (val1 == PEM_INVALID_CHAR) {
        DEBUG ((EFI_D_ERROR, "Cannot decode PEM string -- invalid character -3\n"));
        return FALSE;
      }

      if (val1 != PEM_PAD_CHAR) {
        decodedValue[1] = ((val2 << 4) | (val1 >> 2));
        val2            = DecodePEMChar (*pStr++);
        if (val2 == PEM_INVALID_CHAR) {
          DEBUG ((EFI_D_ERROR, "Cannot decode PEM string -- invalid character -4\n"));
          return FALSE;
        }

        if (val2 == PEM_PAD_CHAR) {
          padBytes = 1;
        } else {
          decodedValue[2] = ((val1 << 6) | val2);
        }
      } else {
        val2 = DecodePEMChar (*pStr++);
        if (val2 != PEM_PAD_CHAR) {
          DEBUG ((EFI_D_ERROR, "Cannot decode PEM string -- invalid encoding -4\n"));
          return FALSE;
        }

        padBytes = 2;
      }

      decodedBytes = (3 - padBytes);
      if (curOutLen < decodedBytes) {
        DEBUG ((EFI_D_ERROR, "Cannot decode PEM string -- out buffer too small-5\n"));
        return FALSE;
      }

      for (ii = 0; ii < decodedBytes; ii++) {
        pOut[ii] = decodedValue[ii];

      }

      curOutLen -= decodedBytes;
      pOut += decodedBytes;
    }
  }

  *pBufLength = *pBufLength - curOutLen;
  return TRUE;
}

/**
  Encoded data

  @param[in] pData                Pointer to buffer
  @param[in] dataLength           Length in bytes
  @param[out] pPEMString          Pointer to buffer to receive encoded bytes
  @param[out] pBufLength          Pointer to the size of the output buffer. Upon return this will
                                  contain the length of the encoded data

  @retval Returns status code indicating outcome of operation
**/
BOOLEAN
PEMSMSEncode (
  IN UINT8                        *pData,
  IN UINT32                       dataLength,
  OUT UINT8                       *pPEMString,
  OUT UINT32                      *pBufLength
  )
{
  UINT32  encodeUnits;
  UINT32  paddedInputLength;
  UINT32  padBytes;
  UINT32  outLength;
  UINT8   encodeBuf[3];
  UINT32  i;
  UINT8   *pOctet;
  UINT32  ipos;
  UINT32  opos;
  UINT32  index;

  encodeUnits       = (dataLength + 2) / 3;
  paddedInputLength = encodeUnits * 3;
  padBytes          = paddedInputLength - dataLength;
  outLength         = encodeUnits * 4;
  pOctet            = pData;
  ipos              = 0;
  opos              = 0;

  outLength         = encodeUnits * 4;
  if (outLength % 64) {
    outLength += ((outLength / 64) + 1);
  } else {
    outLength += (outLength / 64);

  }

  outLength++;
  DEBUG ((EFI_D_ERROR, "ATAM: Pbuflength: %d OutLength: %d \n", *pBufLength, outLength));
  if (*pBufLength < outLength) {
    DEBUG ((EFI_D_ERROR, "ATAM: Failed \n"));
    return FALSE;
  }

  for (i = 0; i < encodeUnits; i++) {
    if ((i == encodeUnits - 1) && (padBytes > 0)) {
      //
      // Encode last piece, with padding
      //
      encodeBuf[0]  = *pOctet++;
      encodeBuf[1]                                  = (padBytes == 1) ? encodeBuf[1] = *pOctet++ : 0;
      encodeBuf[2] = 0;
      ipos += (3 - padBytes);

      index               = encodeBuf[0] >> 2;
      pPEMString[opos++]  = PEMCodes[index];
      index               = ((encodeBuf[0] & 0x03) << 4) | (encodeBuf[1] >> 4);
      pPEMString[opos++]  = PEMCodes[index];

      if (padBytes == 1) {
        index               = ((encodeBuf[1] & 0x0f) << 2) | (encodeBuf[2] >> 6);
        pPEMString[opos++]  = PEMCodes[index];
        pPEMString[opos++]  = '=';
      } else {
        pPEMString[opos++]  = '=';
        pPEMString[opos++]  = '=';
      }
    } else {
      //
      // Encode next 3 bytes
      //
      encodeBuf[0]  = *pOctet++;
      encodeBuf[1]  = *pOctet++;
      encodeBuf[2]  = *pOctet++;
      ipos += 3;
      index               = encodeBuf[0] >> 2;
      pPEMString[opos++]  = PEMCodes[index];
      index               = ((encodeBuf[0] & 0x03) << 4) | (encodeBuf[1] >> 4);
      pPEMString[opos++]  = PEMCodes[index];
      index               = ((encodeBuf[1] & 0x0f) << 2) | (encodeBuf[2] >> 6);
      pPEMString[opos++]  = PEMCodes[index];
      index               = encodeBuf[2] & 0x3f;
      pPEMString[opos++]  = PEMCodes[index];
    }
  }

  pPEMString[opos]  = 0;
  *pBufLength       = opos;

  return TRUE;
}

#ifdef EFI_DEBUG

/**
  This routine displays the debug message in ASCII

  @param[in] Message              Message to be displayed
  @param[in] Length               Length of the message

  @retval None
**/
VOID
ShowBuffer (
  IN UINT8                        *Message,
  IN UINT32                       Length
  )
{
  UINT32  LineBreak;
  UINT32  Index;
  LineBreak = 0;
  Index     = 0;

  while (Length-- > 0) {
    if (LineBreak == 0) {
      DEBUG ((EFI_D_ERROR, "%02x: ", (Index & 0xF0)));
    }

    DEBUG ((EFI_D_ERROR, "%02x ", Message[Index++]));
    LineBreak++;
    if (LineBreak == 16) {
      DEBUG ((EFI_D_ERROR, "\n"));
      LineBreak = 0;
    }

    if (LineBreak == 8) {
      DEBUG ((EFI_D_ERROR, "- "));
    }
  }

  DEBUG ((EFI_D_ERROR, "\n"));
  return ;
}

#endif // End Of EFI_DEBUG