From 514eb9ba987b05985e92e9e4eaa08d476cbf1081 Mon Sep 17 00:00:00 2001
From: Audric Ackermann <audric@loki.network>
Date: Thu, 17 Sep 2020 19:46:06 +1000
Subject: [PATCH] fix pubkey regex for mobile medium groups

---
 ts/receiver/contentMessage.ts                              | 2 +-
 .../outgoing/content/data/group/ClosedGroupMessage.ts      | 7 ++++++-
 ts/session/types/PubKey.ts                                 | 1 -
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/ts/receiver/contentMessage.ts b/ts/receiver/contentMessage.ts
index 646582bfb..77780f73a 100644
--- a/ts/receiver/contentMessage.ts
+++ b/ts/receiver/contentMessage.ts
@@ -80,7 +80,7 @@ async function decryptForMediumGroup(
     window.console.info(
       'Dropping message from ourself after decryptForMediumGroup'
     );
-    return;
+    return null;
   }
 
   const plaintext = await decryptWithSenderKey(
diff --git a/ts/session/messages/outgoing/content/data/group/ClosedGroupMessage.ts b/ts/session/messages/outgoing/content/data/group/ClosedGroupMessage.ts
index 9b6c80704..c17fdbe4f 100644
--- a/ts/session/messages/outgoing/content/data/group/ClosedGroupMessage.ts
+++ b/ts/session/messages/outgoing/content/data/group/ClosedGroupMessage.ts
@@ -32,7 +32,12 @@ export abstract class ClosedGroupMessage extends DataMessage {
   }
 
   protected groupContext(): SignalService.GroupContext {
-    const id = new Uint8Array(StringUtils.encode(this.groupId.key, 'utf8'));
+    let groupIdWithPrefix: string = this.groupId.key;
+    if (!this.groupId.key.startsWith(PubKey.PREFIX_GROUP_TEXTSECURE)) {
+      groupIdWithPrefix = PubKey.PREFIX_GROUP_TEXTSECURE + this.groupId.key;
+    }
+    const encoded = StringUtils.encode(groupIdWithPrefix, 'utf8');
+    const id = new Uint8Array(encoded);
 
     return new SignalService.GroupContext({ id });
   }
diff --git a/ts/session/types/PubKey.ts b/ts/session/types/PubKey.ts
index db333185d..7e63b32e9 100644
--- a/ts/session/types/PubKey.ts
+++ b/ts/session/types/PubKey.ts
@@ -8,7 +8,6 @@ export class PubKey {
   // tslint:disable: member-ordering
   public static readonly regexForPubkeys = `((05)?${PubKey.HEX}{64})`;
   public static readonly PREFIX_GROUP_TEXTSECURE = '__textsecure_group__!';
-
   // prettier-ignore
   private static readonly regex: RegExp = new RegExp(
     `^(${PubKey.PREFIX_GROUP_TEXTSECURE})?(05)?(${PubKey.HEX}{64}|${PubKey.HEX}{32})$`