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Code Issues Packages Projects Releases Wiki Activity

Move PreKey ids to be Mediums, generate in circular buffer.

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This commit is contained in:
Moxie Marlinspike
2013-08-19 10:07:07 -07:00
parent edb89ee3e9
commit d1969412fb
14 changed files with 153 additions and 43 deletions
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73
library/src/org/whispersystems/textsecure/crypto/PreKeyUtil.java
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@@ -3,16 +3,17 @@ package org.whispersystems.textsecure.crypto;
import android.content.Context;
import android.util.Log;
import com.google.protobuf.ByteString;
import org.whispersystems.textsecure.encoded.PreKeyProtos.PreKeyEntity;
import org.whispersystems.textsecure.push.PreKeyList;
import com.google.thoughtcrimegson.Gson;
import org.whispersystems.textsecure.storage.InvalidKeyIdException;
import org.whispersystems.textsecure.storage.PreKeyRecord;
import org.whispersystems.textsecure.util.Base64;
import org.whispersystems.textsecure.util.Medium;
import org.whispersystems.textsecure.util.Util;
import java.io.File;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.Comparator;
import java.util.LinkedList;
@@ -24,17 +25,18 @@ public class PreKeyUtil {
public static List<PreKeyRecord> generatePreKeys(Context context, MasterSecret masterSecret) {
List<PreKeyRecord> records = new LinkedList<PreKeyRecord>();
long preKeyIdOffset = getNextPreKeyId(context);
int preKeyIdOffset = getNextPreKeyId(context);
for (int i=0;i<BATCH_SIZE;i++) {
Log.w("PreKeyUtil", "Generating PreKey: " + (preKeyIdOffset + i));
PreKeyPair keyPair = new PreKeyPair(masterSecret, KeyUtil.generateKeyPair());
PreKeyRecord record = new PreKeyRecord(context, masterSecret, preKeyIdOffset + i, keyPair);
int preKeyId = (preKeyIdOffset + i) % Medium.MAX_VALUE;
PreKeyPair keyPair = new PreKeyPair(masterSecret, KeyUtil.generateKeyPair());
PreKeyRecord record = new PreKeyRecord(context, masterSecret, preKeyId, keyPair);
record.save();
records.add(record);
}
setNextPreKeyId(context, (preKeyIdOffset + BATCH_SIZE + 1) % Medium.MAX_VALUE);
return records;
}
@@ -47,7 +49,7 @@ public class PreKeyUtil {
for (String keyRecordId : keyRecordIds) {
try {
records.add(new PreKeyRecord(context, masterSecret, Long.parseLong(keyRecordId)));
records.add(new PreKeyRecord(context, masterSecret, Integer.parseInt(keyRecordId)));
} catch (InvalidKeyIdException e) {
Log.w("PreKeyUtil", e);
new File(getPreKeysDirectory(context), keyRecordId).delete();
@@ -69,23 +71,32 @@ public class PreKeyUtil {
}
}
private static long getNextPreKeyId(Context context) {
private static void setNextPreKeyId(Context context, int id) {
try {
File directory = getPreKeysDirectory(context);
String[] keyRecordIds = directory.list();
long nextPreKeyId = 0;
File nextFile = new File(getPreKeysDirectory(context), PreKeyIndex.FILE_NAME);
FileOutputStream fout = new FileOutputStream(nextFile);
fout.write(new Gson().toJson(new PreKeyIndex(id)).getBytes());
fout.close();
} catch (IOException e) {
Log.w("PreKeyUtil", e);
}
}
for (String keyRecordId : keyRecordIds) {
if (Long.parseLong(keyRecordId) > nextPreKeyId)
nextPreKeyId = Long.parseLong(keyRecordId);
private static int getNextPreKeyId(Context context) {
try {
File nextFile = new File(getPreKeysDirectory(context), PreKeyIndex.FILE_NAME);
if (nextFile.exists()) {
return Util.getSecureRandom().nextInt(Medium.MAX_VALUE);
} else {
InputStreamReader reader = new InputStreamReader(new FileInputStream(nextFile));
PreKeyIndex index = new Gson().fromJson(reader, PreKeyIndex.class);
reader.close();
return index.nextPreKeyId;
}
if (nextPreKeyId == 0)
nextPreKeyId = SecureRandom.getInstance("SHA1PRNG").nextInt(Integer.MAX_VALUE/2);
return nextPreKeyId;
} catch (NoSuchAlgorithmException e) {
throw new AssertionError(e);
} catch (IOException e) {
Log.w("PreKeyUtil", e);
return Util.getSecureRandom().nextInt(Medium.MAX_VALUE);
}
}
@@ -114,4 +125,16 @@ public class PreKeyUtil {
}
}
private static class PreKeyIndex {
public static final String FILE_NAME = "index.dat";
private int nextPreKeyId;
public PreKeyIndex() {}
public PreKeyIndex(int nextPreKeyId) {
this.nextPreKeyId = nextPreKeyId;
}
}
}