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
|
/*************************************************
* Diffie-Hellman Source File *
* (C) 1999-2007 Jack Lloyd *
*************************************************/
#include <botan/dh.h>
#include <botan/numthry.h>
#include <botan/libstate.h>
#include <botan/util.h>
namespace Botan {
/*************************************************
* DH_PublicKey Constructor *
*************************************************/
DH_PublicKey::DH_PublicKey(const DL_Group& grp, const BigInt& y1)
{
group = grp;
y = y1;
X509_load_hook(global_state().prng_reference());
}
/*************************************************
* Algorithm Specific X.509 Initialization Code *
*************************************************/
void DH_PublicKey::X509_load_hook(RandomNumberGenerator& rng)
{
load_check(rng);
}
/*************************************************
* Return the maximum input size in bits *
*************************************************/
u32bit DH_PublicKey::max_input_bits() const
{
return group_p().bits();
}
/*************************************************
* Return the public value for key agreement *
*************************************************/
MemoryVector<byte> DH_PublicKey::public_value() const
{
return BigInt::encode_1363(y, group_p().bytes());
}
/*************************************************
* Create a DH private key *
*************************************************/
DH_PrivateKey::DH_PrivateKey(const DL_Group& grp,
RandomNumberGenerator& rng)
{
group = grp;
const BigInt& p = group_p();
x.randomize(rng, 2 * dl_work_factor(p.bits()));
PKCS8_load_hook(rng, true);
}
/*************************************************
* DH_PrivateKey Constructor *
*************************************************/
DH_PrivateKey::DH_PrivateKey(const DL_Group& grp, const BigInt& x1,
const BigInt& y1)
{
group = grp;
y = y1;
x = x1;
PKCS8_load_hook(global_state().prng_reference());
}
/*************************************************
* Algorithm Specific PKCS #8 Initialization Code *
*************************************************/
void DH_PrivateKey::PKCS8_load_hook(RandomNumberGenerator& rng,
bool generated)
{
if(y == 0)
y = power_mod(group_g(), x, group_p());
core = DH_Core(rng, group, x);
if(generated)
gen_check(rng);
else
load_check(rng);
}
/*************************************************
* Return the public value for key agreement *
*************************************************/
MemoryVector<byte> DH_PrivateKey::public_value() const
{
return DH_PublicKey::public_value();
}
/*************************************************
* Derive a key *
*************************************************/
SecureVector<byte> DH_PrivateKey::derive_key(const byte w[],
u32bit w_len) const
{
return derive_key(BigInt::decode(w, w_len));
}
/*************************************************
* Derive a key *
*************************************************/
SecureVector<byte> DH_PrivateKey::derive_key(const DH_PublicKey& key) const
{
return derive_key(key.get_y());
}
/*************************************************
* Derive a key *
*************************************************/
SecureVector<byte> DH_PrivateKey::derive_key(const BigInt& w) const
{
const BigInt& p = group_p();
if(w <= 1 || w >= p-1)
throw Invalid_Argument(algo_name() + "::derive_key: Invalid key input");
return BigInt::encode_1363(core.agree(w), p.bytes());
}
}
|
