diff options
Diffstat (limited to 'src/main/java/eu/siacs/conversations/crypto/axolotl/XmppAxolotlMessage.java')
| -rw-r--r-- | src/main/java/eu/siacs/conversations/crypto/axolotl/XmppAxolotlMessage.java | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/src/main/java/eu/siacs/conversations/crypto/axolotl/XmppAxolotlMessage.java b/src/main/java/eu/siacs/conversations/crypto/axolotl/XmppAxolotlMessage.java index 981b93ec..3fcd0fcf 100644 --- a/src/main/java/eu/siacs/conversations/crypto/axolotl/XmppAxolotlMessage.java +++ b/src/main/java/eu/siacs/conversations/crypto/axolotl/XmppAxolotlMessage.java @@ -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 |