Crypto++  5.6.3
Free C++ class library of cryptographic schemes
md2.cpp
1 // md2.cpp - modified by Wei Dai from Andrew M. Kuchling's md2.c
2 // The original code and all modifications are in the public domain.
3 
4 // This is the original introductory comment:
5 
6 /*
7  * md2.c : MD2 hash algorithm.
8  *
9  * Part of the Python Cryptography Toolkit, version 1.1
10  *
11  * Distribute and use freely; there are no restrictions on further
12  * dissemination and usage except those imposed by the laws of your
13  * country of residence.
14  *
15  */
16 
17 #include "pch.h"
18 #define CRYPTOPP_ENABLE_NAMESPACE_WEAK 1
19 #include "md2.h"
20 
21 NAMESPACE_BEGIN(CryptoPP)
22 namespace Weak1 {
23 
24 MD2::MD2()
25  : m_X(48), m_C(16), m_buf(16)
26 {
27  Init();
28 }
29 
30 void MD2::Init()
31 {
32  memset(m_X, 0, 48);
33  memset(m_C, 0, 16);
34  memset(m_buf, 0, 16);
35  m_count = 0;
36 }
37 
38 void MD2::Update(const byte *buf, size_t len)
39 {
40  static const byte S[256] = {
41  41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
42  19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
43  76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
44  138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
45  245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
46  148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
47  39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
48  181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
49  150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
50  112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
51  96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
52  85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
53  234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
54  129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
55  8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
56  203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
57  166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
58  31, 26, 219, 153, 141, 51, 159, 17, 131, 20
59  };
60 
61  while (len)
62  {
63  unsigned int L = UnsignedMin(16U-m_count, len);
64  memcpy(m_buf+m_count, buf, L);
65  m_count+=L;
66  buf+=L;
67  len-=L;
68  if (m_count==16)
69  {
70  byte t;
71  int i,j;
72 
73  m_count=0;
74  memcpy(m_X+16, m_buf, 16);
75  t=m_C[15];
76  for(i=0; i<16; i++)
77  {
78  m_X[32+i]=m_X[16+i]^m_X[i];
79  t=m_C[i]^=S[m_buf[i]^t];
80  }
81 
82  t=0;
83  for(i=0; i<18; i++)
84  {
85  for(j=0; j<48; j+=8)
86  {
87  t=m_X[j+0]^=S[t];
88  t=m_X[j+1]^=S[t];
89  t=m_X[j+2]^=S[t];
90  t=m_X[j+3]^=S[t];
91  t=m_X[j+4]^=S[t];
92  t=m_X[j+5]^=S[t];
93  t=m_X[j+6]^=S[t];
94  t=m_X[j+7]^=S[t];
95  }
96  t = byte((t+i) & 0xFF);
97  }
98  }
99  }
100 }
101 
102 void MD2::TruncatedFinal(byte *hash, size_t size)
103 {
104  ThrowIfInvalidTruncatedSize(size);
105 
106  byte padding[16];
107  word32 padlen;
108  unsigned int i;
109 
110  padlen= 16-m_count;
111  for(i=0; i<padlen; i++) padding[i]=(byte)padlen;
112  Update(padding, padlen);
113  Update(m_C, 16);
114  memcpy(hash, m_X, size);
115 
116  Init();
117 }
118 
119 }
120 NAMESPACE_END
const T1 UnsignedMin(const T1 &a, const T2 &b)
Safe comparison of values that could be neagtive and incorrectly promoted.
Definition: misc.h:486
Crypto++ library namespace.