aboutsummaryrefslogtreecommitdiffstats
path: root/src/pubkey/ecdsa/ecdsa.cpp
blob: aba571eb6678807fb35d11069366398f3a836857 (plain)
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
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
/*
* ECDSA implemenation
* (C) 2007 Manuel Hartl, FlexSecure GmbH
*     2007 Falko Strenzke, FlexSecure GmbH
*     2008 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/

#include <botan/ecdsa.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 {

ECDSA_PrivateKey::ECDSA_PrivateKey(RandomNumberGenerator& rng,
                                   const EC_Domain_Params& dom_pars)
   {
   mp_dom_pars = std::unique_ptr<EC_Domain_Params>(new EC_Domain_Params(dom_pars));
   generate_private_key(rng);

   try
      {
      mp_public_point->check_invariants();
      }
   catch(Illegal_Point& e)
      {
      throw Invalid_State("ECDSA key generation failed");
      }

   m_ecdsa_core = ECDSA_Core(*mp_dom_pars, m_private_value, *mp_public_point);
   }

ECDSA_PrivateKey::ECDSA_PrivateKey(const EC_Domain_Params& domain,
                                   const BigInt& x)
   {
   mp_dom_pars = std::auto_ptr<EC_Domain_Params>(new EC_Domain_Params(domain));

   m_private_value = x;
   mp_public_point = std::auto_ptr<PointGFp>(new PointGFp (mp_dom_pars->get_base_point()));
   mp_public_point->mult_this_secure(m_private_value,
                                     mp_dom_pars->get_order(),
                                     mp_dom_pars->get_order()-1);

   try
      {
      mp_public_point->check_invariants();
      }
   catch(Illegal_Point& e)
      {
      throw Invalid_State("ECDSA key generation failed");
      }

   m_ecdsa_core = ECDSA_Core(*mp_dom_pars, m_private_value, *mp_public_point);
   }

/*
* ECDSA_PublicKey
*/
void ECDSA_PublicKey::affirm_init() const // virtual
   {
   EC_PublicKey::affirm_init();
   }

void ECDSA_PublicKey::set_domain_parameters(const EC_Domain_Params& dom_pars)
   {
   if(mp_dom_pars.get())
      {
      // they are already set, we must ensure that they are equal to the arg
      if(dom_pars != *mp_dom_pars.get())
         throw Invalid_Argument("EC_PublicKey::set_domain_parameters - cannot reset to a new value");

      return;
      }

   if(m_enc_public_point.size() == 0)
      throw Invalid_State("EC_PublicKey::set_domain_parameters(): encoded public point isn't set");

   // now try to decode the public key ...
   PointGFp tmp_pp(OS2ECP(m_enc_public_point, dom_pars.get_curve()));
   try
      {
      tmp_pp.check_invariants();
      }
   catch(Illegal_Point e)
      {
      throw Invalid_State("EC_PublicKey::set_domain_parameters(): point does not lie on provided curve");
      }

   mp_dom_pars.reset(new EC_Domain_Params(dom_pars));
   ECDSA_Core tmp_ecdsa_core(*mp_dom_pars, BigInt(0), tmp_pp);
   mp_public_point.reset(new PointGFp(tmp_pp));
   m_ecdsa_core = tmp_ecdsa_core;
   }

void ECDSA_PublicKey::set_all_values(const ECDSA_PublicKey& other)
   {
   m_param_enc = other.m_param_enc;
   m_ecdsa_core = other.m_ecdsa_core;
   m_enc_public_point = other.m_enc_public_point;
   if(other.mp_dom_pars.get())
      mp_dom_pars.reset(new EC_Domain_Params(other.domain_parameters()));

   if(other.mp_public_point.get())
      mp_public_point.reset(new PointGFp(other.public_point()));
   }

ECDSA_PublicKey::ECDSA_PublicKey(const ECDSA_PublicKey& other)
   : Public_Key(),
     EC_PublicKey(),
     PK_Verifying_wo_MR_Key()
   {
   set_all_values(other);
   }

const ECDSA_PublicKey& ECDSA_PublicKey::operator=(const ECDSA_PublicKey& rhs)
   {
   set_all_values(rhs);
   return *this;
   }

bool ECDSA_PublicKey::verify(const byte msg[], u32bit msg_len,
                             const byte sig[], u32bit sig_len) const
   {
   affirm_init();

   return m_ecdsa_core.verify(msg, msg_len, sig, sig_len);
   }

ECDSA_PublicKey::ECDSA_PublicKey(const EC_Domain_Params& dom_par,
                                 const PointGFp& public_point)
   {
   mp_dom_pars = std::unique_ptr<EC_Domain_Params>(new EC_Domain_Params(dom_par));
   mp_public_point = std::unique_ptr<PointGFp>(new PointGFp(public_point));
   m_param_enc = ENC_EXPLICIT;
   m_ecdsa_core = ECDSA_Core(*mp_dom_pars, BigInt(0), *mp_public_point);
   }

void ECDSA_PublicKey::X509_load_hook()
   {
   EC_PublicKey::X509_load_hook();
   EC_PublicKey::affirm_init();
   m_ecdsa_core = ECDSA_Core ( *mp_dom_pars, BigInt ( 0 ), *mp_public_point );
   }

u32bit ECDSA_PublicKey::max_input_bits() const
   {
   if(!mp_dom_pars.get())
      {
      throw Invalid_State("ECDSA_PublicKey::max_input_bits(): domain parameters not set");
      }
   return mp_dom_pars->get_order().bits();
   }

/*************************
* ECDSA_PrivateKey
*************************/
void ECDSA_PrivateKey::affirm_init() const // virtual
   {
   EC_PrivateKey::affirm_init();
   }

void ECDSA_PrivateKey::PKCS8_load_hook(bool generated)
   {
   EC_PrivateKey::PKCS8_load_hook(generated);
   EC_PrivateKey::affirm_init();
   m_ecdsa_core = ECDSA_Core(*mp_dom_pars, m_private_value, *mp_public_point);
   }

void ECDSA_PrivateKey::set_all_values(const ECDSA_PrivateKey& other)
   {
   m_private_value = other.m_private_value;
   m_param_enc = other.m_param_enc;
   m_ecdsa_core = other.m_ecdsa_core;
   m_enc_public_point = other.m_enc_public_point;

   if(other.mp_dom_pars.get())
      mp_dom_pars.reset(new EC_Domain_Params(other.domain_parameters()));

   if(other.mp_public_point.get())
      mp_public_point.reset(new PointGFp(other.public_point()));
   }

ECDSA_PrivateKey::ECDSA_PrivateKey(ECDSA_PrivateKey const& other)
   : Public_Key(),
     EC_PublicKey(),
     Private_Key(),
     ECDSA_PublicKey(),
     EC_PrivateKey(),
     PK_Signing_Key()
   {
   set_all_values(other);
   }

const ECDSA_PrivateKey& ECDSA_PrivateKey::operator=(const ECDSA_PrivateKey& rhs)
   {
   set_all_values(rhs);
   return *this;
   }

SecureVector<byte> ECDSA_PrivateKey::sign(const byte msg[],
                                          u32bit msg_len,
                                          RandomNumberGenerator& rng) const
   {
   affirm_init();

   const BigInt& n = mp_dom_pars->get_order();

   BigInt k;
   do
      k.randomize(rng, n.bits()-1);
   while(k >= n);

   return m_ecdsa_core.sign(msg, msg_len, k);
   }

}