Read support for 12-byte IVs in addition to 16-byte IVs

1 files changed, 7 insertions, 0 deletions

diff --git a/src/main/java/de/pixart/messenger/entities/DownloadableFile.java b/src/main/java/de/pixart/messenger/entities/DownloadableFile.java
index 94fae97a4..6993b6b38 100644
--- a/src/main/java/de/pixart/messenger/entities/DownloadableFile.java
+++ b/src/main/java/de/pixart/messenger/entities/DownloadableFile.java
@@ -50,11 +50,18 @@ public class DownloadableFile extends File {
     }
 
     public void setKeyAndIv(byte[] keyIvCombo) {
+        // originally, we used a 16 byte IV, then found for aes-gcm a 12 byte IV is ideal
+        // this code supports reading either length, with sending 12 byte IV to be done in future
         if (keyIvCombo.length == 48) {
             this.aeskey = new byte[32];
             this.iv = new byte[16];
             System.arraycopy(keyIvCombo, 0, this.iv, 0, 16);
             System.arraycopy(keyIvCombo, 16, this.aeskey, 0, 32);
+        } else if (keyIvCombo.length == 44) {
+            this.aeskey = new byte[32];
+            this.iv = new byte[12];
+            System.arraycopy(keyIvCombo, 0, this.iv, 0, 12);
+            System.arraycopy(keyIvCombo, 12, this.aeskey, 0, 32);
         } else if (keyIvCombo.length >= 32) {
             this.aeskey = new byte[32];
             System.arraycopy(keyIvCombo, 0, aeskey, 0, 32);