From 5d84bddc62e658c946fbba67265fe13d1e2705b2 Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Mon, 11 Aug 2025 10:58:24 +0300
Subject: [PATCH] crypto/attachments: hash correct data while decrypting

---
 crypto/attachment/attachments.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/crypto/attachment/attachments.go b/crypto/attachment/attachments.go
index 65c76f5a..155cca5c 100644
--- a/crypto/attachment/attachments.go
+++ b/crypto/attachment/attachments.go
@@ -207,8 +207,13 @@ func (r *encryptingReader) Read(dst []byte) (n int, err error) {
 		}
 	}
 	n, err = r.source.Read(dst)
+	if r.isDecrypting {
+		r.hash.Write(dst[:n])
+	}
 	r.stream.XORKeyStream(dst[:n], dst[:n])
-	r.hash.Write(dst[:n])
+	if !r.isDecrypting {
+		r.hash.Write(dst[:n])
+	}
 	return
 }