Crypto++
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