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
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
|
/*
* Nyberg-Rueppel
* (C) 1999-2010 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/nr.h>
#include <botan/numthry.h>
#include <botan/keypair.h>
#include <botan/look_pk.h>
namespace Botan {
NR_PublicKey::NR_PublicKey(const AlgorithmIdentifier& alg_id,
const MemoryRegion<byte>& key_bits) :
DL_Scheme_PublicKey(alg_id, key_bits, DL_Group::ANSI_X9_57)
{
core = NR_Core(group, y);
}
/*
* NR_PublicKey Constructor
*/
NR_PublicKey::NR_PublicKey(const DL_Group& grp, const BigInt& y1)
{
group = grp;
y = y1;
core = NR_Core(group, y);
}
/*
* Nyberg-Rueppel Verification Function
*/
SecureVector<byte> NR_PublicKey::verify(const byte sig[], u32bit sig_len) const
{
return core.verify(sig, sig_len);
}
/*
* Create a NR private key
*/
NR_PrivateKey::NR_PrivateKey(RandomNumberGenerator& rng,
const DL_Group& grp,
const BigInt& x_arg)
{
group = grp;
x = x_arg;
if(x == 0)
x = BigInt::random_integer(rng, 2, group_q() - 1);
y = power_mod(group_g(), x, group_p());
core = NR_Core(group, y, x);
if(x_arg == 0)
gen_check(rng);
else
load_check(rng);
}
NR_PrivateKey::NR_PrivateKey(const AlgorithmIdentifier& alg_id,
const MemoryRegion<byte>& key_bits,
RandomNumberGenerator& rng) :
DL_Scheme_PrivateKey(alg_id, key_bits, DL_Group::ANSI_X9_57)
{
y = power_mod(group_g(), x, group_p());
core = NR_Core(group, y, x);
load_check(rng);
}
/*
* Nyberg-Rueppel Signature Operation
*/
SecureVector<byte> NR_PrivateKey::sign(const byte in[], u32bit length,
RandomNumberGenerator& rng) const
{
const BigInt& q = group_q();
BigInt k;
do
k.randomize(rng, q.bits());
while(k >= q);
return core.sign(in, length, k);
}
/*
* Check Private Nyberg-Rueppel Parameters
*/
bool NR_PrivateKey::check_key(RandomNumberGenerator& rng, bool strong) const
{
if(!DL_Scheme_PrivateKey::check_key(rng, strong) || x >= group_q())
return false;
if(!strong)
return true;
try
{
KeyPair::check_key(rng,
get_pk_signer(*this, "EMSA1(SHA-1)"),
get_pk_verifier(*this, "EMSA1(SHA-1)")
);
}
catch(Self_Test_Failure)
{
return false;
}
return true;
}
NR_Signature_Operation::NR_Signature_Operation(const NR_PrivateKey& nr) :
q(nr.group_q()),
x(nr.get_x()),
powermod_g_p(nr.group_g(), nr.group_p()),
mod_q(nr.group_q())
{
}
SecureVector<byte> NR_Signature_Operation::sign(const byte msg[],
u32bit msg_len,
RandomNumberGenerator& rng)
{
rng.add_entropy(msg, msg_len);
BigInt k;
do
k.randomize(rng, q.bits());
while(k >= q);
BigInt f(msg, msg_len);
if(f >= q)
throw Invalid_Argument("NR_Signature_Operation: Input is out of range");
BigInt c = mod_q.reduce(powermod_g_p(k) + f);
if(c.is_zero())
throw Internal_Error("Default_NR_Op::sign: c was zero");
BigInt d = mod_q.reduce(k - x * c);
SecureVector<byte> output(2*q.bytes());
c.binary_encode(output + (output.size() / 2 - c.bytes()));
d.binary_encode(output + (output.size() - d.bytes()));
return output;
}
}
|
