initial

external/crypto++-5.61/ccm.cpp

@@ -0,0 +1,140 @@
+// ccm.cpp - written and placed in the public domain by Wei Dai
+
+#include "pch.h"
+
+#ifndef CRYPTOPP_IMPORTS
+
+#include "ccm.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+void CCM_Base::SetKeyWithoutResync(const byte *userKey, size_t keylength, const NameValuePairs &params)
+{
+	BlockCipher &blockCipher = AccessBlockCipher();
+
+	blockCipher.SetKey(userKey, keylength, params);
+
+	if (blockCipher.BlockSize() != REQUIRED_BLOCKSIZE)
+		throw InvalidArgument(AlgorithmName() + ": block size of underlying block cipher is not 16");
+
+	m_digestSize = params.GetIntValueWithDefault(Name::DigestSize(), DefaultDigestSize());
+	if (m_digestSize % 2 > 0 || m_digestSize < 4 || m_digestSize > 16)
+		throw InvalidArgument(AlgorithmName() + ": DigestSize must be 4, 6, 8, 10, 12, 14, or 16");
+
+	m_buffer.Grow(2*REQUIRED_BLOCKSIZE);
+	m_L = 8;
+}
+
+void CCM_Base::Resync(const byte *iv, size_t len)
+{
+	BlockCipher &cipher = AccessBlockCipher();
+
+	m_L = REQUIRED_BLOCKSIZE-1-(int)len;
+	assert(m_L >= 2);
+	if (m_L > 8)
+		m_L = 8;
+
+	m_buffer[0] = byte(m_L-1);	// flag
+	memcpy(m_buffer+1, iv, len);
+	memset(m_buffer+1+len, 0, REQUIRED_BLOCKSIZE-1-len);
+
+	if (m_state >= State_IVSet)
+		m_ctr.Resynchronize(m_buffer, REQUIRED_BLOCKSIZE);
+	else
+		m_ctr.SetCipherWithIV(cipher, m_buffer);
+
+	m_ctr.Seek(REQUIRED_BLOCKSIZE);
+	m_aadLength = 0; 
+	m_messageLength = 0;
+}
+
+void CCM_Base::UncheckedSpecifyDataLengths(lword headerLength, lword messageLength, lword footerLength)
+{
+	if (m_state != State_IVSet)
+		throw BadState(AlgorithmName(), "SpecifyDataLengths", "or after State_IVSet");
+
+	m_aadLength = headerLength; 
+	m_messageLength = messageLength;
+
+	byte *cbcBuffer = CBC_Buffer();
+	const BlockCipher &cipher = GetBlockCipher();
+
+	cbcBuffer[0] = byte(64*(headerLength>0) + 8*((m_digestSize-2)/2) + (m_L-1));	// flag
+	PutWord<word64>(true, BIG_ENDIAN_ORDER, cbcBuffer+REQUIRED_BLOCKSIZE-8, m_messageLength);
+	memcpy(cbcBuffer+1, m_buffer+1, REQUIRED_BLOCKSIZE-1-m_L);
+	cipher.ProcessBlock(cbcBuffer);
+
+	if (headerLength>0)
+	{
+		assert(m_bufferedDataLength == 0);
+
+		if (headerLength < ((1<<16) - (1<<8)))
+		{
+			PutWord<word16>(true, BIG_ENDIAN_ORDER, m_buffer, (word16)headerLength);
+			m_bufferedDataLength = 2;
+		}
+		else if (headerLength < (W64LIT(1)<<32))
+		{
+			m_buffer[0] = 0xff;
+			m_buffer[1] = 0xfe;
+			PutWord<word32>(false, BIG_ENDIAN_ORDER, m_buffer+2, (word32)headerLength);
+			m_bufferedDataLength = 6;
+		}
+		else
+		{
+			m_buffer[0] = 0xff;
+			m_buffer[1] = 0xff;
+			PutWord<word64>(false, BIG_ENDIAN_ORDER, m_buffer+2, headerLength);
+			m_bufferedDataLength = 10;
+		}
+	}
+}
+
+size_t CCM_Base::AuthenticateBlocks(const byte *data, size_t len)
+{
+	byte *cbcBuffer = CBC_Buffer();
+	const BlockCipher &cipher = GetBlockCipher();
+	return cipher.AdvancedProcessBlocks(cbcBuffer, data, cbcBuffer, len, BlockTransformation::BT_DontIncrementInOutPointers|BlockTransformation::BT_XorInput);
+}
+
+void CCM_Base::AuthenticateLastHeaderBlock()
+{
+	byte *cbcBuffer = CBC_Buffer();
+	const BlockCipher &cipher = GetBlockCipher();
+
+	if (m_aadLength != m_totalHeaderLength)
+		throw InvalidArgument(AlgorithmName() + ": header length doesn't match that given in SpecifyDataLengths");
+
+	if (m_bufferedDataLength > 0)
+	{
+		xorbuf(cbcBuffer, m_buffer, m_bufferedDataLength);
+		cipher.ProcessBlock(cbcBuffer);
+		m_bufferedDataLength = 0;
+	}
+}
+
+void CCM_Base::AuthenticateLastConfidentialBlock()
+{
+	byte *cbcBuffer = CBC_Buffer();
+	const BlockCipher &cipher = GetBlockCipher();
+
+	if (m_messageLength != m_totalMessageLength)
+		throw InvalidArgument(AlgorithmName() + ": message length doesn't match that given in SpecifyDataLengths");
+
+	if (m_bufferedDataLength > 0)
+	{
+		xorbuf(cbcBuffer, m_buffer, m_bufferedDataLength);
+		cipher.ProcessBlock(cbcBuffer);
+		m_bufferedDataLength = 0;
+	}
+}
+
+void CCM_Base::AuthenticateLastFooterBlock(byte *mac, size_t macSize)
+{
+	m_ctr.Seek(0);
+	m_ctr.ProcessData(mac, CBC_Buffer(), macSize);
+}
+
+NAMESPACE_END
+
+#endif