blowfish: Fix CBC decryption with dst==src

Signed-off-by: Martin Storsjö <martin@martin.st>

diff --git a/libavutil/blowfish.c b/libavutil/blowfish.c
index 35c546a898fc5cd8c428da438ce1aa5db5698168..604c0be8214d82b6b5d90e679d3650c8cdc4f0aa 100644 (file)
--- a/libavutil/blowfish.c
+++ b/libavutil/blowfish.c
@@ -388,15 +388,15 @@ void av_blowfish_crypt(AVBlowfish *ctx, uint8_t *dst, const uint8_t *src,
 
             av_blowfish_crypt_ecb(ctx, &v0, &v1, decrypt);
 
-            AV_WB32(dst, v0);
-            AV_WB32(dst + 4, v1);
-
             if (iv) {
-                for (i = 0; i < 8; i++)
-                    dst[i] = dst[i] ^ iv[i];
+                v0 ^= AV_RB32(iv);
+                v1 ^= AV_RB32(iv + 4);
                 memcpy(iv, src, 8);
             }
 
+            AV_WB32(dst, v0);
+            AV_WB32(dst + 4, v1);
+
             src   += 8;
             dst   += 8;
         }