1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
|
#ifndef BU_CIPHER_H
#define BU_CIPHER_H
#include "bu/filter.h"
#include "bu/util.h"
namespace Bu
{
template<int iBlockSize>
class Cipher : public Bu::Filter
{
public:
Cipher( Bu::Stream &rNext ) :
Bu::Filter( rNext ),
iReadBufFill( 0 ),
iReadBufPos( 0 ),
iWriteBufFill( 0 )
{
}
virtual ~Cipher()
{
}
virtual void start()
{
}
virtual Bu::size stop()
{
return 0;
}
virtual Bu::size read( void *pBuf, Bu::size iBytes )
{
Bu::size iRead = 0;
while( iRead < iBytes )
{
if( iReadBufFill < iBlockSize )
{
int iR = rNext.read(
aReadBuf+iReadBufFill,
iBlockSize-iReadBufFill
);
if( iR == 0 )
return iRead;
iReadBufFill += iR;
if( iReadBufFill == iBlockSize )
decipher( aReadBuf );
}
if( iReadBufFill == iBlockSize )
{
int iCpy = Bu::min( (int)(iBytes-iRead), iBlockSize-iReadBufPos );
memcpy( ((char *)pBuf)+iRead, aReadBuf+iReadBufPos, iCpy );
iRead += iCpy;
iReadBufPos += iCpy;
if( iReadBufPos == iBlockSize )
{
iReadBufPos = iReadBufFill = 0;
}
}
}
return iRead;
}
virtual Bu::size write( const void *pBuf, Bu::size iBytes )
{
Bu::size iPos = 0;
while( iPos < iBytes )
{
int iLeft = Bu::min((int)(iBytes-iPos),iBlockSize-iReadBufFill);
memcpy( aReadBuf+iReadBufFill, (char *)pBuf+iPos, iLeft );
iPos += iLeft;
iReadBufFill += iLeft;
if( iReadBufFill == iBlockSize )
{
encipher( aReadBuf );
rNext.write( aReadBuf, iBlockSize );
iReadBufFill = 0;
}
}
return iPos;
}
using Bu::Stream::read;
using Bu::Stream::write;
protected:
virtual void encipher( void *pData )=0;
virtual void decipher( void *pData )=0;
private:
char aReadBuf[iBlockSize];
char aWriteBuf[iBlockSize];
int iReadBufFill;
int iReadBufPos;
int iWriteBufFill;
};
};
#endif
|
