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
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
|
/*
* X.509 Certificate Authority
* (C) 1999-2010 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/x509_ca.h>
#include <botan/pubkey.h>
#include <botan/der_enc.h>
#include <botan/ber_dec.h>
#include <botan/bigint.h>
#include <botan/parsing.h>
#include <botan/oids.h>
#include <botan/hash.h>
#include <botan/key_constraint.h>
#include <algorithm>
#include <typeinfo>
#include <iterator>
#include <set>
namespace Botan {
/*
* Load the certificate and private key
*/
X509_CA::X509_CA(const X509_Certificate& c,
const Private_Key& key,
const std::string& hash_fn) : cert(c)
{
if(!cert.is_CA_cert())
throw Invalid_Argument("X509_CA: This certificate is not for a CA");
signer = choose_sig_format(key, hash_fn, ca_sig_algo);
}
/*
* X509_CA Destructor
*/
X509_CA::~X509_CA()
{
delete signer;
}
/*
* Sign a PKCS #10 certificate request
*/
X509_Certificate X509_CA::sign_request(const PKCS10_Request& req,
RandomNumberGenerator& rng,
const X509_Time& not_before,
const X509_Time& not_after)
{
Key_Constraints constraints;
if(req.is_CA())
constraints = Key_Constraints(KEY_CERT_SIGN | CRL_SIGN);
else
{
std::unique_ptr<Public_Key> key(req.subject_public_key());
constraints = find_constraints(*key, req.constraints());
}
Extensions extensions;
extensions.add(
new Cert_Extension::Basic_Constraints(req.is_CA(), req.path_limit()),
true);
extensions.add(new Cert_Extension::Key_Usage(constraints), true);
extensions.add(new Cert_Extension::Authority_Key_ID(cert.subject_key_id()));
extensions.add(new Cert_Extension::Subject_Key_ID(req.raw_public_key()));
extensions.add(
new Cert_Extension::Subject_Alternative_Name(req.subject_alt_name()));
extensions.add(
new Cert_Extension::Extended_Key_Usage(req.ex_constraints()));
return make_cert(signer, rng, ca_sig_algo,
req.raw_public_key(),
not_before, not_after,
cert.subject_dn(), req.subject_dn(),
extensions);
}
/*
* Create a new certificate
*/
X509_Certificate X509_CA::make_cert(PK_Signer* signer,
RandomNumberGenerator& rng,
const AlgorithmIdentifier& sig_algo,
const std::vector<byte>& pub_key,
const X509_Time& not_before,
const X509_Time& not_after,
const X509_DN& issuer_dn,
const X509_DN& subject_dn,
const Extensions& extensions)
{
const size_t X509_CERT_VERSION = 3;
const size_t SERIAL_BITS = 128;
BigInt serial_no(rng, SERIAL_BITS);
// clang-format off
return X509_Certificate(X509_Object::make_signed(
signer, rng, sig_algo,
DER_Encoder().start_cons(SEQUENCE)
.start_explicit(0)
.encode(X509_CERT_VERSION-1)
.end_explicit()
.encode(serial_no)
.encode(sig_algo)
.encode(issuer_dn)
.start_cons(SEQUENCE)
.encode(not_before)
.encode(not_after)
.end_cons()
.encode(subject_dn)
.raw_bytes(pub_key)
.start_explicit(3)
.start_cons(SEQUENCE)
.encode(extensions)
.end_cons()
.end_explicit()
.end_cons()
.get_contents()
));;
// clang-format on
}
/*
* Create a new, empty CRL
*/
X509_CRL X509_CA::new_crl(RandomNumberGenerator& rng,
u32bit next_update) const
{
std::vector<CRL_Entry> empty;
return make_crl(empty, 1, next_update, rng);
}
/*
* Update a CRL with new entries
*/
X509_CRL X509_CA::update_crl(const X509_CRL& crl,
const std::vector<CRL_Entry>& new_revoked,
RandomNumberGenerator& rng,
u32bit next_update) const
{
std::vector<CRL_Entry> revoked = crl.get_revoked();
std::copy(new_revoked.begin(), new_revoked.end(),
std::back_inserter(revoked));
return make_crl(revoked, crl.crl_number() + 1, next_update, rng);
}
/*
* Create a CRL
*/
X509_CRL X509_CA::make_crl(const std::vector<CRL_Entry>& revoked,
u32bit crl_number, u32bit next_update,
RandomNumberGenerator& rng) const
{
const size_t X509_CRL_VERSION = 2;
if(next_update == 0)
next_update = timespec_to_u32bit("7d");
// Totally stupid: ties encoding logic to the return of std::time!!
auto current_time = std::chrono::system_clock::now();
auto expire_time = current_time + std::chrono::seconds(next_update);
Extensions extensions;
extensions.add(
new Cert_Extension::Authority_Key_ID(cert.subject_key_id()));
extensions.add(new Cert_Extension::CRL_Number(crl_number));
// clang-format off
const std::vector<byte> crl = X509_Object::make_signed(
signer, rng, ca_sig_algo,
DER_Encoder().start_cons(SEQUENCE)
.encode(X509_CRL_VERSION-1)
.encode(ca_sig_algo)
.encode(cert.issuer_dn())
.encode(X509_Time(current_time))
.encode(X509_Time(expire_time))
.encode_if(revoked.size() > 0,
DER_Encoder()
.start_cons(SEQUENCE)
.encode_list(revoked)
.end_cons()
)
.start_explicit(0)
.start_cons(SEQUENCE)
.encode(extensions)
.end_cons()
.end_explicit()
.end_cons()
.get_contents());
// clang-format on
return X509_CRL(crl);
}
/*
* Return the CA's certificate
*/
X509_Certificate X509_CA::ca_certificate() const
{
return cert;
}
/*
* Choose a signing format for the key
*/
PK_Signer* choose_sig_format(const Private_Key& key,
const std::string& hash_fn,
AlgorithmIdentifier& sig_algo)
{
const std::string algo_name = key.algo_name();
std::unique_ptr<HashFunction> hash(HashFunction::create(hash_fn));
if(!hash)
throw Algorithm_Not_Found(hash_fn);
if(key.max_input_bits() < hash->output_length() * 8)
throw Invalid_Argument("Key is too small for chosen hash function");
std::string padding;
if(algo_name == "RSA")
padding = "EMSA3";
else if(algo_name == "DSA")
padding = "EMSA1";
else if(algo_name == "ECDSA")
padding = "EMSA1_BSI";
else
throw Invalid_Argument("Unknown X.509 signing key type: " + algo_name);
const Signature_Format format = (key.message_parts() > 1) ? DER_SEQUENCE : IEEE_1363;
padding = padding + "(" + hash->name() + ")";
sig_algo.oid = OIDS::lookup(algo_name + "/" + padding);
sig_algo.parameters = key.algorithm_identifier().parameters;
return new PK_Signer(key, padding, format);
}
}
|
