Ensure cloud sync IV is 12 bytes

4 months ago · e63ebe1594
parent 9ffa60c05b
commit e63ebe1594
1 changed files with 3 additions and 2 deletions
--- a/app/src/main/java/eu/faircode/email/CloudSync.java
+++ b/app/src/main/java/eu/faircode/email/CloudSync.java
@ -777,7 +777,8 @@ public class CloudSync {

    private static byte[] getIv(long revision) {
        byte[] iv = ByteBuffer.allocate(12)
-                .putLong(revision)
+                .putLong(revision) // 8 bytes
+                .putInt(0) // 4 bytes
                .array();
        return iv;
    }
@ -785,7 +786,7 @@ public class CloudSync {
    private static byte[] getAd(String key, long revision) throws NoSuchAlgorithmException {
        byte[] k = MessageDigest.getInstance("SHA256").digest(key.getBytes());
        byte[] ad = ByteBuffer.allocate(8 + 8)
-                .putLong(revision)
+                .putLong(revision) // 8 bytes
                .put(Arrays.copyOfRange(k, 0, 8))
                .array();
        return ad;