Crypto++ 7.0 Free C++ class library of cryptographic schemes

mdc.h
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1 // mdc.h - originally written and placed in the public domain by Wei Dai
2
3 /// \file mdc.h
4 /// \brief Classes for the MDC message digest
5
6 #ifndef CRYPTOPP_MDC_H
7 #define CRYPTOPP_MDC_H
8
9 #include "seckey.h"
10 #include "secblock.h"
11 #include "misc.h"
12
13 // GCC cast warning
14 #define HashWordPtr(x) ((HashWordType*)(void*)(x))
15 #define ConstHashWordPtr(x) ((const HashWordType*)(const void*)(x))
16
17 NAMESPACE_BEGIN(CryptoPP)
18
19 /// \tparam B BlockCipher derived class
20 /// \brief MDC_Info cipher information
21 template <class B>
22 struct MDC_Info : public FixedBlockSize<B::DIGESTSIZE>, public FixedKeyLength<B::BLOCKSIZE>
23 {
24 static std::string StaticAlgorithmName() {return std::string("MDC/")+B::StaticAlgorithmName();}
25 };
26
27 /// \brief MDC cipher
28 /// \tparam H HashTransformation derived class
29 /// \details MDC() is a construction by Peter Gutmann to turn an iterated hash function into a PRF
30 /// \sa <a href="http://www.cryptopp.com/wiki/MDC">MDC</a>
31 template <class H>
32 class MDC : public MDC_Info<H>
33 {
34 /// \brief MDC cipher encryption operation
35 class CRYPTOPP_NO_VTABLE Enc : public BlockCipherImpl<MDC_Info<H> >
36 {
37 typedef typename H::HashWordType HashWordType;
38
39 public:
40 void UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs &params)
41 {
42 CRYPTOPP_UNUSED(params);
43 this->AssertValidKeyLength(length);
44 ConditionalByteReverse(BIG_ENDIAN_ORDER, Key(), ConstHashWordPtr(userKey), this->KEYLENGTH);
45 }
46
47 void ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
48 {
49 ConditionalByteReverse(BIG_ENDIAN_ORDER, Buffer(), ConstHashWordPtr(inBlock), this->BLOCKSIZE);
50 H::Transform(Buffer(), Key());
51
52 if (xorBlock)
53 {
54 ConditionalByteReverse(BIG_ENDIAN_ORDER, Buffer(), Buffer(), this->BLOCKSIZE);
55 xorbuf(outBlock, xorBlock, m_buffer, this->BLOCKSIZE);
56 }
57 else
58 {
59 ConditionalByteReverse(BIG_ENDIAN_ORDER, HashWordPtr(outBlock), Buffer(), this->BLOCKSIZE);
60 }
61 }
62
63 bool IsPermutation() const {return false;}
64
65 unsigned int OptimalDataAlignment() const {return sizeof(HashWordType);}
66
67 private:
68 HashWordType *Key() {return HashWordPtr(m_key.data());}
69 const HashWordType *Key() const {return ConstHashWordPtr(m_key.data());}
70 HashWordType *Buffer() const {return HashWordPtr(m_buffer.data());}
71
72 // VC60 workaround: bug triggered if using FixedSizeAllocatorWithCleanup
73 FixedSizeSecBlock<byte, MDC_Info<H>::KEYLENGTH, AllocatorWithCleanup<byte> > m_key;
74 mutable FixedSizeSecBlock<byte, MDC_Info<H>::BLOCKSIZE, AllocatorWithCleanup<byte> > m_buffer;
75 };
76
77 public:
78 // use BlockCipher interface
79 typedef BlockCipherFinal<ENCRYPTION, Enc> Encryption;
80 };
81
82 NAMESPACE_END
83
84 #endif
MDC_Info
MDC_Info cipher information.
Definition: mdc.h:22
FixedKeyLength
Inherited by keyed algorithms with fixed key length.
Definition: seckey.h:124
misc.h
Utility functions for the Crypto++ library.
FixedKeyLength< H ::BLOCKSIZE >::KEYLENGTH
static const int KEYLENGTH
The default key length used by the algorithm provided as a constant.
Definition: seckey.h:129
MDC
MDC cipher.
Definition: mdc.h:32
AllocatorWithCleanup< byte >
secblock.h
Classes and functions for secure memory allocations.
FixedBlockSize
Inherited by algorithms with fixed block size.
Definition: seckey.h:40
seckey.h
Classes and functions for implementing secret key algorithms.
ConditionalByteReverse
T ConditionalByteReverse(ByteOrder order, T value)
Reverses bytes in a value depending upon endianness.
Definition: misc.h:2047
BlockCipherFinal< ENCRYPTION, Enc >
FixedSizeSecBlock
Fixed size stack-based SecBlock.
Definition: secblock.h:1071
BIG_ENDIAN_ORDER
byte order is big-endian
Definition: cryptlib.h:147
xorbuf
void xorbuf(byte *buf, const byte *mask, size_t count)
Performs an XOR of a buffer with a mask.
Definition: misc.cpp:32
BlockCipherImpl
Provides a base implementation of Algorithm and SimpleKeyingInterface for block ciphers.
Definition: seckey.h:305
CryptoPP
Crypto++ library namespace.
FixedBlockSize< H ::DIGESTSIZE >::BLOCKSIZE
static const int BLOCKSIZE
The block size of the algorithm provided as a constant.
Definition: seckey.h:44
Name::Key
const char * Key()
ConstByteArrayParameter.
Definition: argnames.h:20
NameValuePairs
Interface for retrieving values given their names.
Definition: cryptlib.h:293