...and the rest

app/src/main/java/org/thoughtcrime/securesms/backup/FullBackupImporter.kt

@@ -12,6 +12,7 @@ import org.session.libsession.messaging.sending_receiving.attachments.Attachment
 import org.session.libsession.utilities.Address
 import org.session.libsession.utilities.Conversions
 import org.session.libsession.utilities.Util
+import org.session.libsignal.crypto.CipherUtil.CIPHER_LOCK
 import org.session.libsignal.crypto.kdf.HKDFv3
 import org.session.libsignal.utilities.ByteUtil
 import org.session.libsignal.utilities.Log
@@ -243,7 +244,7 @@ object FullBackupImporter {
                 val split = ByteUtil.split(derived, 32, 32)
                 cipherKey = split[0]
                 macKey = split[1]
-                cipher = Cipher.getInstance("AES/CTR/NoPadding")
+                cipher = synchronized(CIPHER_LOCK) { Cipher.getInstance("AES/CTR/NoPadding") }
                 mac = Mac.getInstance("HmacSHA256")
                 mac.init(SecretKeySpec(macKey, "HmacSHA256"))
                 counter = Conversions.byteArrayToInt(iv)
@@ -269,7 +270,12 @@ object FullBackupImporter {
             var length = length
             try {
                 Conversions.intToByteArray(iv, 0, counter++)
-                cipher.init(Cipher.DECRYPT_MODE, SecretKeySpec(cipherKey, "AES"), IvParameterSpec(iv))
+                val plaintext = synchronized(CIPHER_LOCK) {
+                    cipher.init(
+                        Cipher.DECRYPT_MODE,
+                        SecretKeySpec(cipherKey, "AES"),
+                        IvParameterSpec(iv)
+                    )
                     mac.update(iv)
                     val buffer = ByteArray(8192)
                     while (length > 0) {
@@ -282,7 +288,8 @@ object FullBackupImporter {
                         }
                         length -= read
                     }
-                val plaintext = cipher.doFinal()
+                    cipher.doFinal()
+                }
                 if (plaintext != null) {
                     out.write(plaintext, 0, plaintext.size)
                 }
@@ -325,8 +332,10 @@ object FullBackupImporter {
                     throw IOException("Bad MAC")
                 }
                 Conversions.intToByteArray(iv, 0, counter++)
+                val plaintext = synchronized(CIPHER_LOCK) {
                     cipher.init(Cipher.DECRYPT_MODE, SecretKeySpec(cipherKey, "AES"), IvParameterSpec(iv))
-                val plaintext = cipher.doFinal(frame, 0, frame.size - 10)
+                    cipher.doFinal(frame, 0, frame.size - 10)
+                }
                 BackupFrame.parseFrom(plaintext)
             } catch (e: Exception) {
                 when (e) {

app/src/main/java/org/thoughtcrime/securesms/crypto/KeyStoreHelper.java

@@ -1,6 +1,8 @@
 package org.thoughtcrime.securesms.crypto;
 
 
+import static org.session.libsignal.crypto.CipherUtil.CIPHER_LOCK;
+
 import android.os.Build;
 import android.security.keystore.KeyGenParameterSpec;
 import android.security.keystore.KeyProperties;
@@ -45,11 +47,11 @@ public final class KeyStoreHelper {
   private static final String ANDROID_KEY_STORE = "AndroidKeyStore";
   private static final String KEY_ALIAS         = "SignalSecret";
 
-  @RequiresApi(Build.VERSION_CODES.M)
   public static SealedData seal(@NonNull byte[] input) {
     SecretKey secretKey = getOrCreateKeyStoreEntry();
 
     try {
+      synchronized (CIPHER_LOCK) {
         Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
         cipher.init(Cipher.ENCRYPT_MODE, secretKey);
 
@@ -57,32 +59,32 @@ public final class KeyStoreHelper {
         byte[] data = cipher.doFinal(input);
 
         return new SealedData(iv, data);
+      }
     } catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException | IllegalBlockSizeException | BadPaddingException e) {
       throw new AssertionError(e);
     }
   }
 
-  @RequiresApi(Build.VERSION_CODES.M)
   public static byte[] unseal(@NonNull SealedData sealedData) {
     SecretKey secretKey = getKeyStoreEntry();
 
     try {
+      synchronized (CIPHER_LOCK) {
         Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
         cipher.init(Cipher.DECRYPT_MODE, secretKey, new GCMParameterSpec(128, sealedData.iv));
 
         return cipher.doFinal(sealedData.data);
+      }
     } catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException | InvalidAlgorithmParameterException | IllegalBlockSizeException | BadPaddingException e) {
       throw new AssertionError(e);
     }
   }
 
-  @RequiresApi(Build.VERSION_CODES.M)
   private static SecretKey getOrCreateKeyStoreEntry() {
     if (hasKeyStoreEntry()) return getKeyStoreEntry();
     else                    return createKeyStoreEntry();
   }
 
-  @RequiresApi(Build.VERSION_CODES.M)
   private static SecretKey createKeyStoreEntry() {
     try {
       KeyGenerator keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, ANDROID_KEY_STORE);
@@ -99,7 +101,6 @@ public final class KeyStoreHelper {
     }
   }
 
-  @RequiresApi(Build.VERSION_CODES.M)
   private static SecretKey getKeyStoreEntry() {
     KeyStore keyStore = getKeyStore();
 
@@ -137,7 +138,6 @@ public final class KeyStoreHelper {
     }
   }
 
-  @RequiresApi(Build.VERSION_CODES.M)
   private static boolean hasKeyStoreEntry() {
     try {
       KeyStore ks = KeyStore.getInstance(ANDROID_KEY_STORE);
@@ -202,7 +202,5 @@ public final class KeyStoreHelper {
         return Base64.decode(p.getValueAsString(), Base64.NO_WRAP | Base64.NO_PADDING);
       }
     }
-
   }
-
 }

app/src/main/java/org/thoughtcrime/securesms/logging/LogFile.java

@@ -1,5 +1,7 @@
 package org.thoughtcrime.securesms.logging;
 
+import static org.session.libsignal.crypto.CipherUtil.CIPHER_LOCK;
+
 import androidx.annotation.NonNull;
 
 import org.session.libsession.utilities.Conversions;
@@ -66,6 +68,7 @@ class LogFile {
 
       byte[] plaintext = entry.getBytes();
       try {
+        synchronized (CIPHER_LOCK) {
           cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(secret, "AES"), new IvParameterSpec(ivBuffer));
 
           int cipherLength = cipher.getOutputSize(plaintext.length);
@@ -75,6 +78,7 @@ class LogFile {
           outputStream.write(ivBuffer);
           outputStream.write(Conversions.intToByteArray(cipherLength));
           outputStream.write(ciphertext, 0, cipherLength);
+        }
 
         outputStream.flush();
       } catch (ShortBufferException | InvalidAlgorithmParameterException | InvalidKeyException | BadPaddingException | IllegalBlockSizeException e) {
@@ -134,10 +138,11 @@ class LogFile {
         Util.readFully(inputStream, ciphertext, length);
 
         try {
+          synchronized (CIPHER_LOCK) {
             cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(secret, "AES"), new IvParameterSpec(ivBuffer));
             byte[] plaintext = cipher.doFinal(ciphertext, 0, length);
-
             return new String(plaintext);
+          }
         } catch (InvalidKeyException | InvalidAlgorithmParameterException | IllegalBlockSizeException | BadPaddingException e) {
           throw new AssertionError(e);
         }

libsignal/src/main/java/org/session/libsignal/streams/AttachmentCipherInputStream.java

@@ -6,6 +6,8 @@
 
 package org.session.libsignal.streams;
 
+import static org.session.libsignal.crypto.CipherUtil.CIPHER_LOCK;
+
 import org.session.libsignal.exceptions.InvalidMacException;
 import org.session.libsignal.exceptions.InvalidMessageException;
 import org.session.libsignal.utilities.Util;
@@ -92,19 +94,15 @@ public class AttachmentCipherInputStream extends FilterInputStream {
       byte[] iv = new byte[BLOCK_SIZE];
       readFully(iv);
 
+      synchronized (CIPHER_LOCK) {
         this.cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
         this.cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(cipherKey, "AES"), new IvParameterSpec(iv));
+      }
 
       this.done          = false;
       this.totalRead     = 0;
       this.totalDataSize = totalDataSize;
-    } catch (NoSuchAlgorithmException e) {
+    } catch (NoSuchAlgorithmException | InvalidKeyException | NoSuchPaddingException | InvalidAlgorithmParameterException e) {
-      throw new AssertionError(e);
-    } catch (InvalidKeyException e) {
-      throw new AssertionError(e);
-    } catch (NoSuchPaddingException e) {
-      throw new AssertionError(e);
-    } catch (InvalidAlgorithmParameterException e) {
       throw new AssertionError(e);
     }
   }
@@ -141,15 +139,12 @@ public class AttachmentCipherInputStream extends FilterInputStream {
 
   private int readFinal(byte[] buffer, int offset, int length) throws IOException {
     try {
+      synchronized (CIPHER_LOCK) {
         int flourish = cipher.doFinal(buffer, offset);
-
         done = true;
         return flourish;
-    } catch (IllegalBlockSizeException e) {
+      }
-      throw new IOException(e);
+    } catch (IllegalBlockSizeException | ShortBufferException | BadPaddingException e) {
-    } catch (BadPaddingException e) {
-      throw new IOException(e);
-    } catch (ShortBufferException e) {
       throw new IOException(e);
     }
   }
@@ -234,9 +229,7 @@ public class AttachmentCipherInputStream extends FilterInputStream {
         throw new InvalidMacException("Digest doesn't match!");
       }
 
-    } catch (IOException e) {
+    } catch (IOException | ArithmeticException e) {
-      throw new InvalidMacException(e);
-    } catch (ArithmeticException e) {
       throw new InvalidMacException(e);
     } catch (NoSuchAlgorithmException e) {
       throw new AssertionError(e);