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
|
/*
* ECC Key implemenation
* (C) 2007 Manuel Hartl, FlexSecure GmbH
* Falko Strenzke, FlexSecure GmbH
* 2008-2010 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/ecc_key.h>
#include <botan/x509_key.h>
#include <botan/numthry.h>
#include <botan/der_enc.h>
#include <botan/ber_dec.h>
#include <botan/secmem.h>
#include <botan/point_gfp.h>
namespace Botan {
size_t EC_PublicKey::estimated_strength() const
{
return domain().get_curve().get_p().bits() / 2;
}
EC_PublicKey::EC_PublicKey(const EC_Group& dom_par,
const PointGFp& pub_point) :
domain_params(dom_par), public_key(pub_point),
domain_encoding(EC_DOMPAR_ENC_EXPLICIT)
{
if(domain().get_curve() != public_point().get_curve())
throw Invalid_Argument("EC_PublicKey: curve mismatch in constructor");
}
EC_PublicKey::EC_PublicKey(const AlgorithmIdentifier& alg_id,
const secure_vector<byte>& key_bits)
{
domain_params = EC_Group(alg_id.parameters);
domain_encoding = EC_DOMPAR_ENC_EXPLICIT;
public_key = OS2ECP(key_bits, domain().get_curve());
}
bool EC_PublicKey::check_key(RandomNumberGenerator&,
bool) const
{
return public_point().on_the_curve();
}
AlgorithmIdentifier EC_PublicKey::algorithm_identifier() const
{
return AlgorithmIdentifier(get_oid(), DER_domain());
}
std::vector<byte> EC_PublicKey::x509_subject_public_key() const
{
return unlock(EC2OSP(public_point(), PointGFp::COMPRESSED));
}
void EC_PublicKey::set_parameter_encoding(EC_Group_Encoding form)
{
if(form != EC_DOMPAR_ENC_EXPLICIT &&
form != EC_DOMPAR_ENC_IMPLICITCA &&
form != EC_DOMPAR_ENC_OID)
throw Invalid_Argument("Invalid encoding form for EC-key object specified");
if((form == EC_DOMPAR_ENC_OID) && (domain_params.get_oid() == ""))
throw Invalid_Argument("Invalid encoding form OID specified for "
"EC-key object whose corresponding domain "
"parameters are without oid");
domain_encoding = form;
}
const BigInt& EC_PrivateKey::private_value() const
{
if(private_key == 0)
throw Invalid_State("EC_PrivateKey::private_value - uninitialized");
return private_key;
}
/**
* EC_PrivateKey constructor
*/
EC_PrivateKey::EC_PrivateKey(RandomNumberGenerator& rng,
const EC_Group& ec_group,
const BigInt& x)
{
domain_params = ec_group;
domain_encoding = EC_DOMPAR_ENC_EXPLICIT;
if(x == 0)
private_key = BigInt::random_integer(rng, 1, domain().get_order());
else
private_key = x;
public_key = domain().get_base_point() * private_key;
BOTAN_ASSERT(public_key.on_the_curve(),
"Generated public key point was on the curve");
}
secure_vector<byte> EC_PrivateKey::pkcs8_private_key() const
{
return DER_Encoder()
.start_cons(SEQUENCE)
.encode(static_cast<size_t>(1))
.encode(BigInt::encode_1363(private_key, private_key.bytes()),
OCTET_STRING)
.end_cons()
.get_contents();
}
EC_PrivateKey::EC_PrivateKey(const AlgorithmIdentifier& alg_id,
const secure_vector<byte>& key_bits)
{
domain_params = EC_Group(alg_id.parameters);
domain_encoding = EC_DOMPAR_ENC_EXPLICIT;
OID key_parameters;
secure_vector<byte> public_key_bits;
BER_Decoder(key_bits)
.start_cons(SEQUENCE)
.decode_and_check<size_t>(1, "Unknown version code for ECC key")
.decode_octet_string_bigint(private_key)
.decode_optional(key_parameters, ASN1_Tag(0), PRIVATE)
.decode_optional_string(public_key_bits, BIT_STRING, 1, PRIVATE)
.end_cons();
if(!key_parameters.empty() && key_parameters != alg_id.oid)
throw Decoding_Error("EC_PrivateKey - inner and outer OIDs did not match");
if(public_key_bits.empty())
{
public_key = domain().get_base_point() * private_key;
BOTAN_ASSERT(public_key.on_the_curve(),
"Public point derived from loaded key was on the curve");
}
else
{
public_key = OS2ECP(public_key_bits, domain().get_curve());
// OS2ECP verifies that the point is on the curve
}
}
}
|
