Initial revision

git-svn-id: svn://svn.code.sf.net/p/cryptopp/code/trunk/c5@2 57ff6487-cd31-0410-9ec3-f628ee90f5f0

1 files changed, 99 insertions, 0 deletions

diff --git a/cbcmac.h b/cbcmac.h
new file mode 100644
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--- /dev/null
+++ b/cbcmac.h
@@ -0,0 +1,99 @@
+#ifndef CRYPTOPP_CBCMAC_H
+#define CRYPTOPP_CBCMAC_H
+
+#include "seckey.h"
+#include "secblock.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+template <class T>
+class CBC_MAC_Base : public SameKeyLengthAs<T>, public MessageAuthenticationCode
+{
+public:
+	static std::string StaticAlgorithmName() {return std::string("CBC-MAC(") + T::StaticAlgorithmName() + ")";}
+
+	CBC_MAC_Base() {}
+
+	void CheckedSetKey(void *, Empty empty, const byte *key, unsigned int length, const NameValuePairs &params);
+	void Update(const byte *input, unsigned int length);
+	void TruncatedFinal(byte *mac, unsigned int size);
+	unsigned int DigestSize() const {return m_cipher.BlockSize();}
+
+private:
+	void ProcessBuf();
+	typename T::Encryption m_cipher;
+	SecByteBlock m_reg;
+	unsigned int m_counter;
+};
+
+//! <a href="http://www.weidai.com/scan-mirror/mac.html#CBC-MAC">CBC-MAC</a>
+/*! Compatible with FIPS 113. T should be an encryption class.
+	Secure only for fixed length messages. For variable length
+	messages use DMAC.
+*/
+template <class T>
+class CBC_MAC : public MessageAuthenticationCodeTemplate<CBC_MAC_Base<T> >
+{
+public:
+	CBC_MAC() {}
+	CBC_MAC(const byte *key, unsigned int length=CBC_MAC_Base<T>::DEFAULT_KEYLENGTH)
+		{SetKey(key, length);}
+};
+
+template <class T>
+void CBC_MAC_Base<T>::CheckedSetKey(void *, Empty empty, const byte *key, unsigned int length, const NameValuePairs &params)
+{
+	m_cipher.SetKey(key, length, params);
+	m_reg.CleanNew(m_cipher.BlockSize());
+	m_counter = 0;
+}
+
+template <class T>
+void CBC_MAC_Base<T>::Update(const byte *input, unsigned int length)
+{
+	while (m_counter && length)
+	{
+		m_reg[m_counter++] ^= *input++;
+		if (m_counter == T::BLOCKSIZE)
+			ProcessBuf();
+		length--;
+	}
+
+	while (length >= T::BLOCKSIZE)
+	{
+		xorbuf(m_reg, input, T::BLOCKSIZE);
+		ProcessBuf();
+		input += T::BLOCKSIZE;
+		length -= T::BLOCKSIZE;
+	}
+
+	while (length--)
+	{
+		m_reg[m_counter++] ^= *input++;
+		if (m_counter == T::BLOCKSIZE)
+			ProcessBuf();
+	}
+}
+
+template <class T>
+void CBC_MAC_Base<T>::TruncatedFinal(byte *mac, unsigned int size)
+{
+	ThrowIfInvalidTruncatedSize(size);
+
+	if (m_counter)
+		ProcessBuf();
+
+	memcpy(mac, m_reg, size);
+	memset(m_reg, 0, T::BLOCKSIZE);
+}
+
+template <class T>
+void CBC_MAC_Base<T>::ProcessBuf()
+{
+	m_cipher.ProcessBlock(m_reg);
+	m_counter = 0;
+}
+
+NAMESPACE_END
+
+#endif