Crypto++ 8.0 Free C++ class library of cryptographic schemes

cbcmac.cpp
1 #include "pch.h"
2
3 #ifndef CRYPTOPP_IMPORTS
4
5 #include "cbcmac.h"
6
7 NAMESPACE_BEGIN(CryptoPP)
8
9 void CBC_MAC_Base::UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs &params)
10 {
11 AccessCipher().SetKey(key, length, params);
12 m_reg.CleanNew(AccessCipher().BlockSize());
13 m_counter = 0;
14 }
15
16 void CBC_MAC_Base::Update(const byte *input, size_t length)
17 {
18 unsigned int blockSize = AccessCipher().BlockSize();
19
20 while (m_counter && length)
21 {
22 m_reg[m_counter++] ^= *input++;
23 if (m_counter == blockSize)
24 ProcessBuf();
25 length--;
26 }
27
28 if (length >= blockSize)
29 {
30 size_t leftOver = AccessCipher().AdvancedProcessBlocks(m_reg, input, m_reg, length, BlockTransformation::BT_DontIncrementInOutPointers|BlockTransformation::BT_XorInput);
31 input += (length - leftOver);
32 length = leftOver;
33 }
34
35 while (length--)
36 {
37 m_reg[m_counter++] ^= *input++;
38 if (m_counter == blockSize)
39 ProcessBuf();
40 }
41 }
42
43 void CBC_MAC_Base::TruncatedFinal(byte *mac, size_t size)
44 {
45 ThrowIfInvalidTruncatedSize(size);
46
47 if (m_counter)
48 ProcessBuf();
49
50 memcpy(mac, m_reg, size);
51 memset(m_reg, 0, AccessCipher().BlockSize());
52 }
53
54 void CBC_MAC_Base::ProcessBuf()
55 {
56 AccessCipher().ProcessBlock(m_reg);
57 m_counter = 0;
58 }
59
60 NAMESPACE_END
61
62 #endif
HashTransformation::BlockSize
virtual unsigned int BlockSize() const
Provides the block size of the compression function.
Definition: cryptlib.h:1137
SimpleKeyingInterface::SetKey
virtual void SetKey(const byte *key, size_t length, const NameValuePairs &params=g_nullNameValuePairs)
Sets or reset the key of this object.
Definition: cryptlib.cpp:58
BlockTransformation::BT_DontIncrementInOutPointers
should not modify block pointers
Definition: cryptlib.h:891
cbcmac.h
Classes for CBC MAC.
CBC_MAC_Base
CBC-MAC base class.
Definition: cbcmac.h:17
CBC_MAC_Base::TruncatedFinal
void TruncatedFinal(byte *mac, size_t size)
Computes the hash of the current message.
Definition: cbcmac.cpp:43
BlockTransformation::BlockSize
virtual unsigned int BlockSize() const =0
Provides the block size of the cipher.
BlockTransformation::AdvancedProcessBlocks
virtual size_t AdvancedProcessBlocks(const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, size_t length, word32 flags) const
Encrypt and xor multiple blocks using additional flags.
Definition: cryptlib.cpp:141
pch.h
Precompiled header file.
BlockTransformation::ProcessBlock
void ProcessBlock(const byte *inBlock, byte *outBlock) const
Encrypt or decrypt a block.
Definition: cryptlib.h:851
Name::BlockSize
const char * BlockSize()
int, in bytes
Definition: argnames.h:27
CBC_MAC_Base::Update
void Update(const byte *input, size_t length)
Updates a hash with additional input.
Definition: cbcmac.cpp:16
BlockTransformation::BT_XorInput
Xor inputs before transformation.
Definition: cryptlib.h:893
CryptoPP
Crypto++ library namespace.
NameValuePairs
Interface for retrieving values given their names.
Definition: cryptlib.h:293