/* Microsoft Reference Implementation for TPM 2.0
 *
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 *  included below. This software may be subject to other third party and
 *  contributor rights, including patent rights, and no such rights are granted
 *  under this license.
 *
 *  Copyright (c) Microsoft Corporation
 *
 *  All rights reserved.
 *
 *  BSD License
 *
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 *  are permitted provided that the following conditions are met:
 *
 *  Redistributions of source code must retain the above copyright notice, this list
 *  of conditions and the following disclaimer.
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 *  Redistributions in binary form must reproduce the above copyright notice, this
 *  list of conditions and the following disclaimer in the documentation and/or
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 */
//** Introduction
//
// This file contains the extra functions required for TDES.

//** Includes, Defines, and Typedefs
#include "Tpm.h"

#if ALG_TDES

#  define DES_NUM_WEAK 64
const UINT64 DesWeakKeys[DES_NUM_WEAK] =
    {0x0101010101010101ULL, 0xFEFEFEFEFEFEFEFEULL, 0xE0E0E0E0F1F1F1F1ULL,
     0x1F1F1F1F0E0E0E0EULL, 0x011F011F010E010EULL, 0x1F011F010E010E01ULL,
     0x01E001E001F101F1ULL, 0xE001E001F101F101ULL, 0x01FE01FE01FE01FEULL,
     0xFE01FE01FE01FE01ULL, 0x1FE01FE00EF10EF1ULL, 0xE01FE01FF10EF10EULL,
     0x1FFE1FFE0EFE0EFEULL, 0xFE1FFE1FFE0EFE0EULL, 0xE0FEE0FEF1FEF1FEULL,
     0xFEE0FEE0FEF1FEF1ULL, 0x01011F1F01010E0EULL, 0x1F1F01010E0E0101ULL,
     0xE0E01F1FF1F10E0EULL, 0x0101E0E00101F1F1ULL, 0x1F1FE0E00E0EF1F1ULL,
     0xE0E0FEFEF1F1FEFEULL, 0x0101FEFE0101FEFEULL, 0x1F1FFEFE0E0EFEFEULL,
     0xE0FE011FF1FE010EULL, 0x011F1F01010E0E01ULL, 0x1FE001FE0EF101FEULL,
     0xE0FE1F01F1FE0E01ULL, 0x011FE0FE010EF1FEULL, 0x1FE0E01F0EF1F10EULL,
     0xE0FEFEE0F1FEFEF1ULL, 0x011FFEE0010EFEF1ULL, 0x1FE0FE010EF1FE01ULL,
     0xFE0101FEFE0101FEULL, 0x01E01FFE01F10EFEULL, 0x1FFE01E00EFE01F1ULL,
     0xFE011FE0FE010EF1ULL, 0xFE01E01FFE01F10EULL, 0x1FFEE0010EFEF101ULL,
     0xFE1F01E0FE0E01F1ULL, 0x01E0E00101F1F101ULL, 0x1FFEFE1F0EFEFE0EULL,
     0xFE1FE001FE0EF101ULL, 0x01E0FE1F01F1FE0EULL, 0xE00101E0F10101F1ULL,
     0xFE1F1FFEFE0E0EFEULL, 0x01FE1FE001FE0EF1ULL, 0xE0011FFEF1010EFEULL,
     0xFEE0011FFEF1010EULL, 0x01FEE01F01FEF10EULL, 0xE001FE1FF101FE0EULL,
     0xFEE01F01FEF10E01ULL, 0x01FEFE0101FEFE01ULL, 0xE01F01FEF10E01FEULL,
     0xFEE0E0FEFEF1F1FEULL, 0x1F01011F0E01010EULL, 0xE01F1FE0F10E0EF1ULL,
     0xFEFE0101FEFE0101ULL, 0x1F01E0FE0E01F1FEULL, 0xE01FFE01F10EFE01ULL,
     0xFEFE1F1FFEFE0E0EULL, 0x1F01FEE00E01FEF1ULL, 0xE0E00101F1F10101ULL,
     0xFEFEE0E0FEFEF1F1ULL};

//*** CryptSetOddByteParity()
// This function sets the per byte parity of a 64-bit value. The least-significant
// bit is of each byte is replaced with the odd parity of the other 7 bits in the
// byte. With odd parity, no byte will ever be 0x00.
UINT64
CryptSetOddByteParity(UINT64 k)
{
#  define PMASK 0x0101010101010101ULL
    UINT64 out;
    k |= PMASK;  // set the parity bit
    out = k;
    k ^= k >> 4;
    k ^= k >> 2;
    k ^= k >> 1;
    k &= PMASK;    // odd parity extracted
    out ^= k;      // out is now even parity because parity bit was already set
    out ^= PMASK;  // out is now even parity
    return out;
}

//*** CryptDesIsWeakKey()
// Check to see if a DES key is on the list of weak, semi-weak, or possibly weak
// keys.
//  Return Type: BOOL
//      TRUE(1)         DES key is weak
//      FALSE(0)        DES key is not weak
static BOOL CryptDesIsWeakKey(UINT64 k)
{
    int i;
    //
    for(i = 0; i < DES_NUM_WEAK; i++)
    {
        if(k == DesWeakKeys[i])
            return TRUE;
    }
    return FALSE;
}

//*** CryptDesValidateKey()
// Function to check to see if the input key is a valid DES key where the definition
// of valid is that none of the elements are on the list of weak, semi-weak, or
// possibly weak keys; and that for two keys, K1!=K2, and for three keys that
// K1!=K2 and K2!=K3.
BOOL CryptDesValidateKey(TPM2B_SYM_KEY* desKey  // IN: key to validate
)
{
    UINT64 k[3];
    int    i;
    int    keys = (desKey->t.size + 7) / 8;
    BYTE*  pk   = desKey->t.buffer;
    BOOL   ok;
    //
    // Note: 'keys' is the number of keys, not the maximum index for 'k'
    ok = ((keys == 2) || (keys == 3)) && ((desKey->t.size % 8) == 0);
    for(i = 0; ok && i < keys; pk += 8, i++)
    {
        k[i] = CryptSetOddByteParity(BYTE_ARRAY_TO_UINT64(pk));
        ok   = !CryptDesIsWeakKey(k[i]);
    }
    ok = ok && k[0] != k[1];
    if(keys == 3)
        ok = ok && k[1] != k[2];
    return ok;
}

//*** CryptGenerateKeyDes()
// This function is used to create a DES key of the appropriate size. The key will
// have odd parity in the bytes.
TPM_RC
CryptGenerateKeyDes(TPMT_PUBLIC* publicArea,    // IN/OUT: The public area template
                                                //     for the new key.
                    TPMT_SENSITIVE* sensitive,  // OUT: sensitive area
                    RAND_STATE*     rand        // IN: the "entropy" source for
)
{
    // Assume that the publicArea key size has been validated and is a supported
    // number of bits.
    sensitive->sensitive.sym.t.size =
        BITS_TO_BYTES(publicArea->parameters.symDetail.sym.keyBits.sym);

    // Because we use BYTE_ARRAY_TO_UINT64 below, require the requested DES key
    // to be a multiple of 8 bytes in size.
    if((sensitive->sensitive.sym.t.size % 8) != 0)
    {
        return TPM_RC_SYMMETRIC;
    }

    do
    {
        BYTE* pK = sensitive->sensitive.sym.t.buffer;
        int   i  = (sensitive->sensitive.sym.t.size + 7) / 8;
        // Use the random number generator to generate the required number of bits
        if(DRBG_Generate(rand, pK, sensitive->sensitive.sym.t.size) == 0)
            return TPM_RC_NO_RESULT;
        for(; i > 0; pK += 8, i--)
        {
            UINT64 k = BYTE_ARRAY_TO_UINT64(pK);
            k        = CryptSetOddByteParity(k);
            UINT64_TO_BYTE_ARRAY(k, pK);
        }
    } while(!CryptDesValidateKey(&sensitive->sensitive.sym));
    return TPM_RC_SUCCESS;
}

#endif
//***
