diff options
Diffstat (limited to 'CryptoPP/ccm.cpp')
| -rw-r--r-- | CryptoPP/ccm.cpp | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/CryptoPP/ccm.cpp b/CryptoPP/ccm.cpp new file mode 100644 index 000000000..036878719 --- /dev/null +++ b/CryptoPP/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 ¶ms)
+{
+ 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
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