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
|
/*
* OpenSSL ARC4
* (C) 1999-2007 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/eng_ossl.h>
#include <botan/parsing.h>
#include <openssl/rc4.h>
namespace Botan {
namespace {
/**
* ARC4 as implemented by OpenSSL
*/
class ARC4_OpenSSL : public StreamCipher
{
public:
void clear() { std::memset(&state, 0, sizeof(state)); }
std::string name() const;
StreamCipher* clone() const { return new ARC4_OpenSSL(SKIP); }
ARC4_OpenSSL(u32bit s = 0) : StreamCipher(1, 32), SKIP(s) { clear(); }
~ARC4_OpenSSL() { clear(); }
private:
void cipher(const byte[], byte[], u32bit);
void key_schedule(const byte[], u32bit);
const u32bit SKIP;
RC4_KEY state;
};
/*
* Return the name of this type
*/
std::string ARC4_OpenSSL::name() const
{
if(SKIP == 0) return "ARC4";
if(SKIP == 256) return "MARK-4";
else return "RC4_skip(" + to_string(SKIP) + ")";
}
/*
* ARC4 Key Schedule
*/
void ARC4_OpenSSL::key_schedule(const byte key[], u32bit length)
{
RC4_set_key(&state, length, key);
byte dummy = 0;
for(u32bit j = 0; j != SKIP; j++)
RC4(&state, 1, &dummy, &dummy);
}
/*
* ARC4 Encryption
*/
void ARC4_OpenSSL::cipher(const byte in[], byte out[], u32bit length)
{
RC4(&state, length, in, out);
}
}
/**
* Look for an OpenSSL-suported stream cipher (ARC4)
*/
StreamCipher*
OpenSSL_Engine::find_stream_cipher(const SCAN_Name& request,
Algorithm_Factory&) const
{
if(request.algo_name() == "ARC4")
return new ARC4_OpenSSL(request.arg_as_u32bit(0, 0));
if(request.algo_name() == "RC4_drop")
return new ARC4_OpenSSL(768);
return 0;
}
}
|
