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
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
|
/*************************************************
* PKCS #5 Source File *
* (C) 1999-2007 Jack Lloyd *
*************************************************/
#include <botan/pkcs5.h>
#include <botan/lookup.h>
#include <botan/loadstor.h>
#include <botan/bit_ops.h>
#include <botan/hmac.h>
#include <algorithm>
#include <memory>
namespace Botan {
/*************************************************
* Return a PKCS#5 PBKDF1 derived key *
*************************************************/
OctetString PKCS5_PBKDF1::derive(u32bit key_len,
const std::string& passphrase,
const byte salt[], u32bit salt_size,
u32bit iterations) const
{
if(iterations == 0)
throw Invalid_Argument("PKCS#5 PBKDF1: Invalid iteration count");
std::auto_ptr<HashFunction> hash(get_hash(hash_name));
if(key_len > hash->OUTPUT_LENGTH)
throw Exception("PKCS#5 PBKDF1: Requested output length too long");
hash->update(passphrase);
hash->update(salt, salt_size);
SecureVector<byte> key = hash->final();
for(u32bit j = 1; j != iterations; ++j)
{
hash->update(key);
hash->final(key);
}
return OctetString(key, std::min(key_len, key.size()));
}
/*************************************************
* Return the name of this type *
*************************************************/
std::string PKCS5_PBKDF1::name() const
{
return "PBKDF1(" + hash_name + ")";
}
/*************************************************
* PKCS5_PBKDF1 Constructor *
*************************************************/
PKCS5_PBKDF1::PKCS5_PBKDF1(const std::string& h_name) : hash_name(h_name)
{
if(!have_hash(hash_name))
throw Algorithm_Not_Found(hash_name);
}
/*************************************************
* Return a PKCS#5 PBKDF2 derived key *
*************************************************/
OctetString PKCS5_PBKDF2::derive(u32bit key_len,
const std::string& passphrase,
const byte salt[], u32bit salt_size,
u32bit iterations) const
{
if(iterations == 0)
throw Invalid_Argument("PKCS#5 PBKDF2: Invalid iteration count");
if(passphrase.length() == 0)
throw Invalid_Argument("PKCS#5 PBKDF2: Empty passphrase is invalid");
HMAC hmac(hash_name);
hmac.set_key(reinterpret_cast<const byte*>(passphrase.data()),
passphrase.length());
SecureVector<byte> key(key_len);
byte* T = key.begin();
u32bit counter = 1;
while(key_len)
{
u32bit T_size = std::min(hmac.OUTPUT_LENGTH, key_len);
SecureVector<byte> U(hmac.OUTPUT_LENGTH);
hmac.update(salt, salt_size);
for(u32bit j = 0; j != 4; ++j)
hmac.update(get_byte(j, counter));
hmac.final(U);
xor_buf(T, U, T_size);
for(u32bit j = 1; j != iterations; ++j)
{
hmac.update(U);
hmac.final(U);
xor_buf(T, U, T_size);
}
key_len -= T_size;
T += T_size;
++counter;
}
return key;
}
/*************************************************
* Return the name of this type *
*************************************************/
std::string PKCS5_PBKDF2::name() const
{
return "PBKDF2(" + hash_name + ")";
}
/*************************************************
* PKCS5_PBKDF2 Constructor *
*************************************************/
PKCS5_PBKDF2::PKCS5_PBKDF2(const std::string& h_name) : hash_name(h_name)
{
if(!have_hash(hash_name))
throw Algorithm_Not_Found(hash_name);
}
}
|
