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added omemo padding but disabled by Config.java flag

This commit is contained in:
Daniel Gultsch 2016-12-20 16:12:12 +01:00
parent fbbf1a37b4
commit e5fff42b10
2 changed files with 19 additions and 2 deletions
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1
src/main/java/eu/siacs/conversations/Config.java
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@ -82,6 +82,7 @@ public final class Config {
public static final long OMEMO_AUTO_EXPIRY = 7 * MILLISECONDS_IN_DAY;
public static final boolean REMOVE_BROKEN_DEVICES = false;
public static final boolean OMEMO_PADDING = false;
public static final boolean DISABLE_PROXY_LOOKUP = false; //useful to debug ibb

20
src/main/java/eu/siacs/conversations/crypto/axolotl/XmppAxolotlMessage.java
View File

@ -162,7 +162,7 @@ public class XmppAxolotlMessage {
IvParameterSpec ivSpec = new IvParameterSpec(iv);
Cipher cipher = Cipher.getInstance(CIPHERMODE, PROVIDER);
cipher.init(Cipher.ENCRYPT_MODE, secretKey, ivSpec);
this.ciphertext = cipher.doFinal(plaintext.getBytes());
this.ciphertext = cipher.doFinal(Config.OMEMO_PADDING ? getPaddedBytes(plaintext) : plaintext.getBytes());
} catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException
| IllegalBlockSizeException | BadPaddingException | NoSuchProviderException
| InvalidAlgorithmParameterException e) {
@ -170,6 +170,22 @@ public class XmppAxolotlMessage {
}
}
private static byte[] getPaddedBytes(String plaintext) {
int plainLength = plaintext.getBytes().length;
int pad = Math.max(64,(plainLength / 32 + 1) * 32) - plainLength;
SecureRandom random = new SecureRandom();
int left = random.nextInt(pad);
int right = pad - left;
StringBuilder builder = new StringBuilder(plaintext);
for(int i = 0; i < left; ++i) {
builder.insert(0,random.nextBoolean() ? "\t" : " ");
}
for(int i = 0; i < right; ++i) {
builder.append(random.nextBoolean() ? "\t" : " ");
}
return builder.toString().getBytes();
}
public Jid getFrom() {
return this.from;
}
@ -239,7 +255,7 @@ public class XmppAxolotlMessage {
cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec);
String plaintext = new String(cipher.doFinal(ciphertext));
plaintextMessage = new XmppAxolotlPlaintextMessage(plaintext, session.getFingerprint());
plaintextMessage = new XmppAxolotlPlaintextMessage(Config.OMEMO_PADDING ? plaintext.trim() : plaintext, session.getFingerprint());
} catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException
| InvalidAlgorithmParameterException | IllegalBlockSizeException