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
|
package org.bouncycastle.crypto.tls;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.math.BigInteger;
import java.util.Vector;
import org.bouncycastle.asn1.x509.KeyUsage;
import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
import org.bouncycastle.crypto.params.DHParameters;
import org.bouncycastle.crypto.params.DHPrivateKeyParameters;
import org.bouncycastle.crypto.params.DHPublicKeyParameters;
import org.bouncycastle.crypto.util.PublicKeyFactory;
/**
* (D)TLS DH key exchange.
*/
public class TlsDHKeyExchange
extends AbstractTlsKeyExchange
{
protected TlsSigner tlsSigner;
protected DHParameters dhParameters;
protected AsymmetricKeyParameter serverPublicKey;
protected TlsAgreementCredentials agreementCredentials;
protected DHPrivateKeyParameters dhAgreePrivateKey;
protected DHPublicKeyParameters dhAgreePublicKey;
public TlsDHKeyExchange(int keyExchange, Vector supportedSignatureAlgorithms, DHParameters dhParameters)
{
super(keyExchange, supportedSignatureAlgorithms);
switch (keyExchange)
{
case KeyExchangeAlgorithm.DH_RSA:
case KeyExchangeAlgorithm.DH_DSS:
this.tlsSigner = null;
break;
case KeyExchangeAlgorithm.DHE_RSA:
this.tlsSigner = new TlsRSASigner();
break;
case KeyExchangeAlgorithm.DHE_DSS:
this.tlsSigner = new TlsDSSSigner();
break;
default:
throw new IllegalArgumentException("unsupported key exchange algorithm");
}
this.dhParameters = dhParameters;
}
public void init(TlsContext context)
{
super.init(context);
if (this.tlsSigner != null)
{
this.tlsSigner.init(context);
}
}
public void skipServerCredentials()
throws IOException
{
throw new TlsFatalAlert(AlertDescription.unexpected_message);
}
public void processServerCertificate(Certificate serverCertificate)
throws IOException
{
if (serverCertificate.isEmpty())
{
throw new TlsFatalAlert(AlertDescription.bad_certificate);
}
org.bouncycastle.asn1.x509.Certificate x509Cert = serverCertificate.getCertificateAt(0);
SubjectPublicKeyInfo keyInfo = x509Cert.getSubjectPublicKeyInfo();
try
{
this.serverPublicKey = PublicKeyFactory.createKey(keyInfo);
}
catch (RuntimeException e)
{
throw new TlsFatalAlert(AlertDescription.unsupported_certificate, e);
}
if (tlsSigner == null)
{
try
{
this.dhAgreePublicKey = TlsDHUtils.validateDHPublicKey((DHPublicKeyParameters)this.serverPublicKey);
}
catch (ClassCastException e)
{
throw new TlsFatalAlert(AlertDescription.certificate_unknown, e);
}
TlsUtils.validateKeyUsage(x509Cert, KeyUsage.keyAgreement);
}
else
{
if (!tlsSigner.isValidPublicKey(this.serverPublicKey))
{
throw new TlsFatalAlert(AlertDescription.certificate_unknown);
}
TlsUtils.validateKeyUsage(x509Cert, KeyUsage.digitalSignature);
}
super.processServerCertificate(serverCertificate);
}
public boolean requiresServerKeyExchange()
{
switch (keyExchange)
{
case KeyExchangeAlgorithm.DHE_DSS:
case KeyExchangeAlgorithm.DHE_RSA:
case KeyExchangeAlgorithm.DH_anon:
return true;
default:
return false;
}
}
public void validateCertificateRequest(CertificateRequest certificateRequest)
throws IOException
{
short[] types = certificateRequest.getCertificateTypes();
for (int i = 0; i < types.length; ++i)
{
switch (types[i])
{
case ClientCertificateType.rsa_sign:
case ClientCertificateType.dss_sign:
case ClientCertificateType.rsa_fixed_dh:
case ClientCertificateType.dss_fixed_dh:
case ClientCertificateType.ecdsa_sign:
break;
default:
throw new TlsFatalAlert(AlertDescription.illegal_parameter);
}
}
}
public void processClientCredentials(TlsCredentials clientCredentials)
throws IOException
{
if (clientCredentials instanceof TlsAgreementCredentials)
{
// TODO Validate client cert has matching parameters (see 'areCompatibleParameters')?
this.agreementCredentials = (TlsAgreementCredentials)clientCredentials;
}
else if (clientCredentials instanceof TlsSignerCredentials)
{
// OK
}
else
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
}
public void generateClientKeyExchange(OutputStream output)
throws IOException
{
/*
* RFC 2246 7.4.7.2 If the client certificate already contains a suitable Diffie-Hellman
* key, then Yc is implicit and does not need to be sent again. In this case, the Client Key
* Exchange message will be sent, but will be empty.
*/
if (agreementCredentials == null)
{
this.dhAgreePrivateKey = TlsDHUtils.generateEphemeralClientKeyExchange(context.getSecureRandom(),
dhParameters, output);
}
}
public void processClientCertificate(Certificate clientCertificate) throws IOException
{
// TODO Extract the public key
// TODO If the certificate is 'fixed', take the public key as dhAgreeClientPublicKey
}
public void processClientKeyExchange(InputStream input) throws IOException
{
if (dhAgreePublicKey != null)
{
// For dss_fixed_dh and rsa_fixed_dh, the key arrived in the client certificate
return;
}
BigInteger Yc = TlsDHUtils.readDHParameter(input);
this.dhAgreePublicKey = TlsDHUtils.validateDHPublicKey(new DHPublicKeyParameters(Yc, dhParameters));
}
public byte[] generatePremasterSecret()
throws IOException
{
if (agreementCredentials != null)
{
return agreementCredentials.generateAgreement(dhAgreePublicKey);
}
if (dhAgreePrivateKey != null)
{
return TlsDHUtils.calculateDHBasicAgreement(dhAgreePublicKey, dhAgreePrivateKey);
}
throw new TlsFatalAlert(AlertDescription.internal_error);
}
}
|
