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
|
package org.spongycastle.cms.jcajce;
import java.security.GeneralSecurityException;
import java.security.InvalidAlgorithmParameterException;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.Provider;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.CertificateEncodingException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.List;
import javax.crypto.Cipher;
import javax.crypto.KeyAgreement;
import javax.crypto.SecretKey;
import org.spongycastle.asn1.ASN1Encodable;
import org.spongycastle.asn1.ASN1EncodableVector;
import org.spongycastle.asn1.ASN1ObjectIdentifier;
import org.spongycastle.asn1.ASN1OctetString;
import org.spongycastle.asn1.ASN1Sequence;
import org.spongycastle.asn1.DEROctetString;
import org.spongycastle.asn1.DERSequence;
import org.spongycastle.asn1.cms.KeyAgreeRecipientIdentifier;
import org.spongycastle.asn1.cms.RecipientEncryptedKey;
import org.spongycastle.asn1.cms.RecipientKeyIdentifier;
import org.spongycastle.asn1.cms.ecc.MQVuserKeyingMaterial;
import org.spongycastle.asn1.x509.AlgorithmIdentifier;
import org.spongycastle.asn1.x509.SubjectPublicKeyInfo;
import org.spongycastle.cms.CMSAlgorithm;
import org.spongycastle.cms.CMSEnvelopedGenerator;
import org.spongycastle.cms.CMSException;
import org.spongycastle.cms.KeyAgreeRecipientInfoGenerator;
import org.spongycastle.jce.interfaces.ECPublicKey;
import org.spongycastle.jce.spec.ECParameterSpec;
import org.spongycastle.jce.spec.MQVPrivateKeySpec;
import org.spongycastle.jce.spec.MQVPublicKeySpec;
import org.spongycastle.operator.GenericKey;
public class JceKeyAgreeRecipientInfoGenerator
extends KeyAgreeRecipientInfoGenerator
{
private List recipientIDs = new ArrayList();
private List recipientKeys = new ArrayList();
private PublicKey senderPublicKey;
private PrivateKey senderPrivateKey;
private EnvelopedDataHelper helper = new EnvelopedDataHelper(new DefaultJcaJceExtHelper());
private SecureRandom random;
private KeyPair ephemeralKP;
public JceKeyAgreeRecipientInfoGenerator(ASN1ObjectIdentifier keyAgreementOID, PrivateKey senderPrivateKey, PublicKey senderPublicKey, ASN1ObjectIdentifier keyEncryptionOID)
{
super(keyAgreementOID, SubjectPublicKeyInfo.getInstance(senderPublicKey.getEncoded()), keyEncryptionOID);
this.senderPublicKey = senderPublicKey;
this.senderPrivateKey = senderPrivateKey;
}
public JceKeyAgreeRecipientInfoGenerator setProvider(Provider provider)
{
this.helper = new EnvelopedDataHelper(new ProviderJcaJceExtHelper(provider));
return this;
}
public JceKeyAgreeRecipientInfoGenerator setProvider(String providerName)
{
this.helper = new EnvelopedDataHelper(new NamedJcaJceExtHelper(providerName));
return this;
}
public JceKeyAgreeRecipientInfoGenerator setSecureRandom(SecureRandom random)
{
this.random = random;
return this;
}
/**
* Add a recipient based on the passed in certificate's public key and its issuer and serial number.
*
* @param recipientCert recipient's certificate
* @return the current instance.
* @throws CertificateEncodingException if the necessary data cannot be extracted from the certificate.
*/
public JceKeyAgreeRecipientInfoGenerator addRecipient(X509Certificate recipientCert)
throws CertificateEncodingException
{
recipientIDs.add(new KeyAgreeRecipientIdentifier(CMSUtils.getIssuerAndSerialNumber(recipientCert)));
recipientKeys.add(recipientCert.getPublicKey());
return this;
}
/**
* Add a recipient identified by the passed in subjectKeyID and the for the passed in public key.
*
* @param subjectKeyID identifier actual recipient will use to match the private key.
* @param publicKey the public key for encrypting the secret key.
* @return the current instance.
* @throws CertificateEncodingException
*/
public JceKeyAgreeRecipientInfoGenerator addRecipient(byte[] subjectKeyID, PublicKey publicKey)
throws CertificateEncodingException
{
recipientIDs.add(new KeyAgreeRecipientIdentifier(new RecipientKeyIdentifier(subjectKeyID)));
recipientKeys.add(publicKey);
return this;
}
public ASN1Sequence generateRecipientEncryptedKeys(AlgorithmIdentifier keyAgreeAlgorithm, AlgorithmIdentifier keyEncryptionAlgorithm, GenericKey contentEncryptionKey)
throws CMSException
{
init(keyAgreeAlgorithm.getAlgorithm());
PrivateKey senderPrivateKey = this.senderPrivateKey;
ASN1ObjectIdentifier keyAgreementOID = keyAgreeAlgorithm.getAlgorithm();
if (keyAgreementOID.getId().equals(CMSEnvelopedGenerator.ECMQV_SHA1KDF))
{
senderPrivateKey = new MQVPrivateKeySpec(
senderPrivateKey, ephemeralKP.getPrivate(), ephemeralKP.getPublic());
}
ASN1EncodableVector recipientEncryptedKeys = new ASN1EncodableVector();
for (int i = 0; i != recipientIDs.size(); i++)
{
PublicKey recipientPublicKey = (PublicKey)recipientKeys.get(i);
KeyAgreeRecipientIdentifier karId = (KeyAgreeRecipientIdentifier)recipientIDs.get(i);
if (keyAgreementOID.getId().equals(CMSEnvelopedGenerator.ECMQV_SHA1KDF))
{
recipientPublicKey = new MQVPublicKeySpec(recipientPublicKey, recipientPublicKey);
}
try
{
// Use key agreement to choose a wrap key for this recipient
KeyAgreement keyAgreement = helper.createKeyAgreement(keyAgreementOID);
keyAgreement.init(senderPrivateKey, random);
keyAgreement.doPhase(recipientPublicKey, true);
SecretKey keyEncryptionKey = keyAgreement.generateSecret(keyEncryptionAlgorithm.getAlgorithm().getId());
// Wrap the content encryption key with the agreement key
Cipher keyEncryptionCipher = helper.createCipher(keyEncryptionAlgorithm.getAlgorithm());
keyEncryptionCipher.init(Cipher.WRAP_MODE, keyEncryptionKey, random);
byte[] encryptedKeyBytes = keyEncryptionCipher.wrap(helper.getJceKey(contentEncryptionKey));
ASN1OctetString encryptedKey = new DEROctetString(encryptedKeyBytes);
recipientEncryptedKeys.add(new RecipientEncryptedKey(karId, encryptedKey));
}
catch (NoSuchAlgorithmException e)
{
throw new CMSException("cannot perform agreement step: " + e.getMessage(), e);
}
catch (InvalidKeyException e)
{
throw new CMSException("cannot perform agreement step: " + e.getMessage(), e);
}
catch (GeneralSecurityException e)
{
throw new CMSException("cannot perform agreement step: " + e.getMessage(), e);
}
}
return new DERSequence(recipientEncryptedKeys);
}
protected ASN1Encodable getUserKeyingMaterial(AlgorithmIdentifier keyAgreeAlg)
throws CMSException
{
init(keyAgreeAlg.getAlgorithm());
if (ephemeralKP != null)
{
return new MQVuserKeyingMaterial(
createOriginatorPublicKey(SubjectPublicKeyInfo.getInstance(ephemeralKP.getPublic().getEncoded())), null);
}
return null;
}
private void init(ASN1ObjectIdentifier keyAgreementOID)
throws CMSException
{
if (random == null)
{
random = new SecureRandom();
}
if (keyAgreementOID.equals(CMSAlgorithm.ECMQV_SHA1KDF))
{
if (ephemeralKP == null)
{
throw new CMSException(
"cannot determine MQV ephemeral key pair parameters from public key");
}
}
}
}
|
