After the 8-byte size header, there are two one-byte headers
and two bytes of padding before the crypt_header field.
Our QCOW1_HDR_CRYPT constant did not skip the padding.
http://git.qemu.org/?p=qemu.git;a=blob;f=block/qcow.c;h=
ece22697#l41
https://bugzilla.redhat.com/show_bug.cgi?id=
1185165
#define QCOWX_HDR_BACKING_FILE_SIZE (QCOWX_HDR_BACKING_FILE_OFFSET+8)
#define QCOWX_HDR_IMAGE_SIZE (QCOWX_HDR_BACKING_FILE_SIZE+4+4)
-#define QCOW1_HDR_CRYPT (QCOWX_HDR_IMAGE_SIZE+8+1+1)
+#define QCOW1_HDR_CRYPT (QCOWX_HDR_IMAGE_SIZE+8+1+1+2)
#define QCOW2_HDR_CRYPT (QCOWX_HDR_IMAGE_SIZE+8)
#define QCOW1_HDR_TOTAL_SIZE (QCOW1_HDR_CRYPT+4+8)