From 491b0c7c15e5a343cadabdf9cb7560956c9bb077 Mon Sep 17 00:00:00 2001
From: Vitaly Chikunov <vt@altlinux.org>
Date: Sun, 10 May 2020 01:20:40 +0300
Subject: [PATCH] gost_crypt: Fix Magma CBC in-place decryption

Simplest fix not concerned with performance, still should not impact it
too much.
---
 gost_crypt.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gost_crypt.c b/gost_crypt.c
index ffb577d..33dc668 100644
--- a/gost_crypt.c
+++ b/gost_crypt.c
@@ -774,10 +774,11 @@ int magma_cipher_do_cbc(EVP_CIPHER_CTX *ctx, unsigned char *out,
                 d[7 - i] = in_ptr[i];
             }
             gostdecrypt(&(c->cctx), d, b);
+            memcpy(d, in_ptr, 8);
             for (i = 0; i < 8; i++) {
                 out_ptr[i] = iv[i] ^ b[7 - i];
             }
-            memcpy(iv, in_ptr, 8);
+            memcpy(iv, d, 8);
             out_ptr += 8;
             in_ptr += 8;
             inl -= 8;
-- 
2.39.2