Method UncheckedSetKey

src/cryptopp/vmac.cpp:55–112

#endif

void VMAC_Base::UncheckedSetKey(const byte *userKey, unsigned int keylength, const NameValuePairs &params)
{
	int digestLength = params.GetIntValueWithDefault(Name::DigestSize(), DefaultDigestSize());
	if (digestLength != 8 && digestLength != 16)
		throw InvalidArgument("VMAC: DigestSize must be 8 or 16");
	m_is128 = digestLength == 16;

	m_L1KeyLength = params.GetIntValueWithDefault(Name::L1KeyLength(), 128);
	if (m_L1KeyLength <= 0 || m_L1KeyLength % 128 != 0)
		throw InvalidArgument("VMAC: L1KeyLength must be a positive multiple of 128");

	AllocateBlocks();

	BlockCipher &cipher = AccessCipher();
	cipher.SetKey(userKey, keylength, params);
	const unsigned int blockSize = cipher.BlockSize();
	const unsigned int blockSizeInWords = blockSize / sizeof(word64);
	SecBlock<word64> out(blockSizeInWords);
	SecByteBlock in;
	in.CleanNew(blockSize);
	size_t i;

	/* Fill nh key */
	in[0] = 0x80;
	cipher.AdvancedProcessBlocks(in, NULL, (byte *)m_nhKey(), m_nhKeySize()*sizeof(word64), cipher.BT_InBlockIsCounter);
	ConditionalByteReverse<word64>(BIG_ENDIAN_ORDER, m_nhKey(), m_nhKey(), m_nhKeySize()*sizeof(word64));

	/* Fill poly key */
	in[0] = 0xC0;
	in[15] = 0;
	for (i = 0; i <= (size_t)m_is128; i++)
	{
		cipher.ProcessBlock(in, out.BytePtr());
		m_polyState()[i*4+2] = GetWord<word64>(true, BIG_ENDIAN_ORDER, out.BytePtr()) & mpoly;
		m_polyState()[i*4+3]  = GetWord<word64>(true, BIG_ENDIAN_ORDER, out.BytePtr()+8) & mpoly;
		in[15]++;
	}

	/* Fill ip key */
	in[0] = 0xE0;
	in[15] = 0;
	word64 *l3Key = m_l3Key();
	CRYPTOPP_ASSERT(IsAlignedOn(l3Key,GetAlignmentOf<word64>()));

	for (i = 0; i <= (size_t)m_is128; i++)
		do
		{
			cipher.ProcessBlock(in, out.BytePtr());
			l3Key[i*2+0] = GetWord<word64>(true, BIG_ENDIAN_ORDER, out.BytePtr());
			l3Key[i*2+1] = GetWord<word64>(true, BIG_ENDIAN_ORDER, out.BytePtr()+8);
			in[15]++;
		} while ((l3Key[i*2+0] >= p64) || (l3Key[i*2+1] >= p64));

	m_padCached = false;
	size_t nonceLength;
	const byte *nonce = GetIVAndThrowIfInvalid(params, nonceLength);
	Resynchronize(nonce, (int)nonceLength);
}