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
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
|
package org.sufficientlysecure.keychain.pgp;
import org.spongycastle.bcpg.HashAlgorithmTags;
import org.spongycastle.bcpg.S2K;
import org.spongycastle.openpgp.PGPException;
import org.spongycastle.openpgp.PGPPrivateKey;
import org.spongycastle.openpgp.PGPPublicKey;
import org.spongycastle.openpgp.PGPPublicKeyRing;
import org.spongycastle.openpgp.PGPSecretKey;
import org.spongycastle.openpgp.PGPSignature;
import org.spongycastle.openpgp.PGPSignatureGenerator;
import org.spongycastle.openpgp.PGPSignatureSubpacketGenerator;
import org.spongycastle.openpgp.PGPSignatureSubpacketVector;
import org.spongycastle.openpgp.PGPUtil;
import org.spongycastle.openpgp.PGPV3SignatureGenerator;
import org.spongycastle.openpgp.operator.PBESecretKeyDecryptor;
import org.spongycastle.openpgp.operator.PGPContentSignerBuilder;
import org.spongycastle.openpgp.operator.PublicKeyDataDecryptorFactory;
import org.spongycastle.openpgp.operator.jcajce.JcaPGPContentSignerBuilder;
import org.spongycastle.openpgp.operator.jcajce.JcePBESecretKeyDecryptorBuilder;
import org.spongycastle.openpgp.operator.jcajce.JcePublicKeyDataDecryptorFactoryBuilder;
import org.spongycastle.openpgp.operator.jcajce.NfcSyncPGPContentSignerBuilder;
import org.sufficientlysecure.keychain.Constants;
import org.sufficientlysecure.keychain.pgp.exception.PgpGeneralException;
import org.sufficientlysecure.keychain.pgp.exception.PgpGeneralMsgIdException;
import org.sufficientlysecure.keychain.util.IterableIterator;
import org.sufficientlysecure.keychain.util.Log;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.SignatureException;
import java.util.Date;
import java.util.LinkedList;
import java.util.List;
/** Wrapper for a PGPSecretKey.
*
* This object can only be obtained from a WrappedSecretKeyRing, and stores a
* back reference to its parent.
*
* This class represents known secret keys which are stored in the database.
* All "crypto operations using a known secret key" should be implemented in
* this class, to ensure on type level that these operations are performed on
* properly imported secret keys only.
*
*/
public class WrappedSecretKey extends WrappedPublicKey {
private final PGPSecretKey mSecretKey;
private PGPPrivateKey mPrivateKey = null;
private int mPrivateKeyState = PRIVATE_KEY_STATE_LOCKED;
private static int PRIVATE_KEY_STATE_LOCKED = 0;
private static int PRIVATE_KEY_STATE_UNLOCKED = 1;
private static int PRIVATE_KEY_STATE_DIVERT_TO_CARD = 2;
WrappedSecretKey(WrappedSecretKeyRing ring, PGPSecretKey key) {
super(ring, key.getPublicKey());
mSecretKey = key;
}
public WrappedSecretKeyRing getRing() {
return (WrappedSecretKeyRing) mRing;
}
/** Returns the wrapped PGPSecretKeyRing.
* This function is for compatibility only, should not be used anymore and will be removed
*/
@Deprecated
public PGPSecretKey getKeyExternal() {
return mSecretKey;
}
/**
* Returns true on right passphrase
*/
public boolean unlock(String passphrase) throws PgpGeneralException {
// handle keys on OpenPGP cards like they were unlocked
if (mSecretKey.getS2K().getType() == S2K.GNU_DUMMY_S2K
&& mSecretKey.getS2K().getProtectionMode() == S2K.GNU_PROTECTION_MODE_DIVERT_TO_CARD) {
mPrivateKeyState = PRIVATE_KEY_STATE_DIVERT_TO_CARD;
return true;
}
// try to extract keys using the passphrase
try {
PBESecretKeyDecryptor keyDecryptor = new JcePBESecretKeyDecryptorBuilder().setProvider(
Constants.BOUNCY_CASTLE_PROVIDER_NAME).build(passphrase.toCharArray());
mPrivateKey = mSecretKey.extractPrivateKey(keyDecryptor);
mPrivateKeyState = PRIVATE_KEY_STATE_UNLOCKED;
} catch (PGPException e) {
return false;
}
if(mPrivateKey == null) {
throw new PgpGeneralException("error extracting key");
}
return true;
}
// TODO: just a hack currently
public LinkedList<Integer> getSupportedHashAlgorithms() {
LinkedList<Integer> supported = new LinkedList<Integer>();
if (mPrivateKeyState == PRIVATE_KEY_STATE_DIVERT_TO_CARD) {
// TODO: only works with SHA256 ?!
supported.add(HashAlgorithmTags.SHA256);
} else {
supported.add(HashAlgorithmTags.MD5);
supported.add(HashAlgorithmTags.RIPEMD160);
supported.add(HashAlgorithmTags.SHA1);
supported.add(HashAlgorithmTags.SHA224);
supported.add(HashAlgorithmTags.SHA256);
supported.add(HashAlgorithmTags.SHA384);
supported.add(HashAlgorithmTags.SHA512); // preferred is latest
}
return supported;
}
public PGPSignatureGenerator getSignatureGenerator(int hashAlgo, boolean cleartext,
byte[] nfcSignedHash, Date nfcCreationTimestamp)
throws PgpGeneralException {
if (mPrivateKeyState == PRIVATE_KEY_STATE_LOCKED) {
throw new PrivateKeyNotUnlockedException();
}
PGPContentSignerBuilder contentSignerBuilder;
if (mPrivateKeyState == PRIVATE_KEY_STATE_DIVERT_TO_CARD) {
// to sign using nfc PgpSignEncrypt is executed two times.
// the first time it stops to return the PendingIntent for nfc connection and signing the hash
// the second time the signed hash is used.
// to get the same hash we cache the timestamp for the second round!
if (nfcCreationTimestamp == null) {
nfcCreationTimestamp = new Date();
}
// use synchronous "NFC based" SignerBuilder
contentSignerBuilder = new NfcSyncPGPContentSignerBuilder(
mSecretKey.getPublicKey().getAlgorithm(), hashAlgo,
mSecretKey.getKeyID(), nfcSignedHash, nfcCreationTimestamp)
.setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME);
Log.d(Constants.TAG, "mSecretKey.getKeyID() "+ PgpKeyHelper.convertKeyIdToHex(mSecretKey.getKeyID()));
} else {
// content signer based on signing key algorithm and chosen hash algorithm
contentSignerBuilder = new JcaPGPContentSignerBuilder(
mSecretKey.getPublicKey().getAlgorithm(), hashAlgo)
.setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME);
}
int signatureType;
if (cleartext) {
// for sign-only ascii text
signatureType = PGPSignature.CANONICAL_TEXT_DOCUMENT;
} else {
signatureType = PGPSignature.BINARY_DOCUMENT;
}
try {
PGPSignatureGenerator signatureGenerator = new PGPSignatureGenerator(contentSignerBuilder);
signatureGenerator.init(signatureType, mPrivateKey);
PGPSignatureSubpacketGenerator spGen = new PGPSignatureSubpacketGenerator();
spGen.setSignerUserID(false, mRing.getPrimaryUserIdWithFallback());
if (nfcCreationTimestamp != null) {
spGen.setSignatureCreationTime(false, nfcCreationTimestamp);
Log.d(Constants.TAG, "For NFC: set sig creation time to " + nfcCreationTimestamp);
}
signatureGenerator.setHashedSubpackets(spGen.generate());
return signatureGenerator;
} catch(PGPException e) {
// TODO: simply throw PGPException!
throw new PgpGeneralException("Error initializing signature!", e);
}
}
public PGPV3SignatureGenerator getV3SignatureGenerator(int hashAlgo, boolean cleartext)
throws PgpGeneralException {
// TODO: divert to card missing
if (mPrivateKeyState != PRIVATE_KEY_STATE_UNLOCKED) {
throw new PrivateKeyNotUnlockedException();
}
// content signer based on signing key algorithm and chosen hash algorithm
JcaPGPContentSignerBuilder contentSignerBuilder = new JcaPGPContentSignerBuilder(
mSecretKey.getPublicKey().getAlgorithm(), hashAlgo)
.setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME);
int signatureType;
if (cleartext) {
// for sign-only ascii text
signatureType = PGPSignature.CANONICAL_TEXT_DOCUMENT;
} else {
signatureType = PGPSignature.BINARY_DOCUMENT;
}
try {
PGPV3SignatureGenerator signatureV3Generator = new PGPV3SignatureGenerator(contentSignerBuilder);
signatureV3Generator.init(signatureType, mPrivateKey);
return signatureV3Generator;
} catch(PGPException e) {
throw new PgpGeneralException("Error initializing signature!", e);
}
}
public PublicKeyDataDecryptorFactory getDecryptorFactory() {
// TODO: divert to card missing
if (mPrivateKeyState != PRIVATE_KEY_STATE_UNLOCKED) {
throw new PrivateKeyNotUnlockedException();
}
return new JcePublicKeyDataDecryptorFactoryBuilder()
.setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME).build(mPrivateKey);
}
/**
* Certify the given pubkeyid with the given masterkeyid.
*
* @param publicKeyRing Keyring to add certification to.
* @param userIds User IDs to certify, must not be null or empty
* @return A keyring with added certifications
*/
public UncachedKeyRing certifyUserIds(WrappedPublicKeyRing publicKeyRing, List<String> userIds)
throws PgpGeneralMsgIdException, NoSuchAlgorithmException, NoSuchProviderException,
PGPException, SignatureException {
// TODO: divert to card missing
if (mPrivateKeyState != PRIVATE_KEY_STATE_UNLOCKED) {
throw new PrivateKeyNotUnlockedException();
}
// create a signatureGenerator from the supplied masterKeyId and passphrase
PGPSignatureGenerator signatureGenerator;
{
// TODO: SHA256 fixed?
JcaPGPContentSignerBuilder contentSignerBuilder = new JcaPGPContentSignerBuilder(
mSecretKey.getPublicKey().getAlgorithm(), PGPUtil.SHA256)
.setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME);
signatureGenerator = new PGPSignatureGenerator(contentSignerBuilder);
signatureGenerator.init(PGPSignature.DEFAULT_CERTIFICATION, mPrivateKey);
}
{ // supply signatureGenerator with a SubpacketVector
PGPSignatureSubpacketGenerator spGen = new PGPSignatureSubpacketGenerator();
PGPSignatureSubpacketVector packetVector = spGen.generate();
signatureGenerator.setHashedSubpackets(packetVector);
}
// get the master subkey (which we certify for)
PGPPublicKey publicKey = publicKeyRing.getPublicKey().getPublicKey();
// fetch public key ring, add the certification and return it
for (String userId : new IterableIterator<String>(userIds.iterator())) {
PGPSignature sig = signatureGenerator.generateCertification(userId, publicKey);
publicKey = PGPPublicKey.addCertification(publicKey, userId, sig);
}
PGPPublicKeyRing ring = PGPPublicKeyRing.insertPublicKey(publicKeyRing.getRing(), publicKey);
return new UncachedKeyRing(ring);
}
static class PrivateKeyNotUnlockedException extends RuntimeException {
// this exception is a programming error which happens when an operation which requires
// the private key is called without a previous call to unlock()
}
public UncachedSecretKey getUncached() {
return new UncachedSecretKey(mSecretKey);
}
// HACK
public PGPSecretKey getSecretKey() {
return mSecretKey;
}
}
|