Crypto++ 8.2 Free C++ class library of cryptographic schemes

blowfish.cpp
1 // blowfish.cpp - originally written and placed in the public domain by Wei Dai
2
3 #include "pch.h"
4 #include "blowfish.h"
5 #include "misc.h"
6
7 NAMESPACE_BEGIN(CryptoPP)
8
9 void Blowfish::Base::UncheckedSetKey(const byte *key_string, unsigned int keylength, const NameValuePairs &)
10 {
11 AssertValidKeyLength(keylength);
12
13 unsigned i, j=0, k;
14 word32 data, dspace[2] = {0, 0};
15
16 memcpy(pbox, p_init, sizeof(p_init));
17 memcpy(sbox, s_init, sizeof(s_init));
18
19 // Xor key string into encryption key vector
20 for (i=0 ; i<ROUNDS+2 ; ++i)
21 {
22 data = 0 ;
23 for (k=0 ; k<4 ; ++k )
24 data = (data << 8) | key_string[j++ % keylength];
25 pbox[i] ^= data;
26 }
27
28 crypt_block(dspace, pbox);
29
30 for (i=0; i<ROUNDS; i+=2)
31 crypt_block(pbox+i, pbox+i+2);
32
33 crypt_block(pbox+ROUNDS, sbox);
34
35 for (i=0; i<4*256-2; i+=2)
36 crypt_block(sbox+i, sbox+i+2);
37
38 if (!IsForwardTransformation())
39 for (i=0; i<(ROUNDS+2)/2; i++)
40 std::swap(pbox[i], pbox[ROUNDS+1-i]);
41 }
42
43 // this version is only used to make pbox and sbox
44 void Blowfish::Base::crypt_block(const word32 in[2], word32 out[2]) const
45 {
46 word32 left = in[0];
47 word32 right = in[1];
48
49 const word32 *const s=sbox;
50 const word32 *p=pbox;
51
52 left ^= p[0];
53
54 for (unsigned i=0; i<ROUNDS/2; i++)
55 {
56 right ^= (((s[GETBYTE(left,3)] + s[256+GETBYTE(left,2)])
57 ^ s[2*256+GETBYTE(left,1)]) + s[3*256+GETBYTE(left,0)])
58 ^ p[2*i+1];
59
60 left ^= (((s[GETBYTE(right,3)] + s[256+GETBYTE(right,2)])
61 ^ s[2*256+GETBYTE(right,1)]) + s[3*256+GETBYTE(right,0)])
62 ^ p[2*i+2];
63 }
64
65 right ^= p[ROUNDS+1];
66
67 out[0] = right;
68 out[1] = left;
69 }
70
71 void Blowfish::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
72 {
73 typedef BlockGetAndPut<word32, BigEndian> Block;
74
75 word32 left, right;
76 Block::Get(inBlock)(left)(right);
77
78 const word32 *const s=sbox;
79 const word32 *p=pbox;
80
81 left ^= p[0];
82
83 for (unsigned i=0; i<ROUNDS/2; i++)
84 {
85 right ^= (((s[GETBYTE(left,3)] + s[256+GETBYTE(left,2)])
86 ^ s[2*256+GETBYTE(left,1)]) + s[3*256+GETBYTE(left,0)])
87 ^ p[2*i+1];
88
89 left ^= (((s[GETBYTE(right,3)] + s[256+GETBYTE(right,2)])
90 ^ s[2*256+GETBYTE(right,1)]) + s[3*256+GETBYTE(right,0)])
91 ^ p[2*i+2];
92 }
93
94 right ^= p[ROUNDS+1];
95
96 Block::Put(xorBlock, outBlock)(right)(left);
97 }
98
99 NAMESPACE_END
misc.h
Utility functions for the Crypto++ library.
BlockGetAndPut
Access a block of memory.
Definition: misc.h:2587
blowfish.h
Classes for the Blowfish block cipher.
pch.h
Precompiled header file.
PutBlock
Access a block of memory.
Definition: misc.h:2550
CryptoPP
Crypto++ library namespace.
swap
void swap(::SecBlock< T, A > &a, ::SecBlock< T, A > &b)
Swap two SecBlocks.
Definition: secblock.h:1159
NameValuePairs
Interface for retrieving values given their names.
Definition: cryptlib.h:321