On Mon, Dec 25, 2023 at 01:45:07PM +0800, Hyman Huang wrote:
> Set the payload_offset_sector to a value that is nearly never reached
> in order to mark it as invalid and indicate that 0 should be the offset
> of the read/write operation on the 'file' protocol blockdev node.
>
> Signed-off-by: Hyman Huang <yong.hu...@smartx.com>
> ---
> crypto/block-luks.c | 41 +++++++++++++++++++++++++++++++----------
> 1 file changed, 31 insertions(+), 10 deletions(-)
>
> diff --git a/crypto/block-luks.c b/crypto/block-luks.c
> index fb01ec38bb..48443ffcae 100644
> --- a/crypto/block-luks.c
> +++ b/crypto/block-luks.c
> @@ -34,6 +34,8 @@
>
> #include "qemu/bitmap.h"
>
> +#define INVALID_SECTOR_OFFSET UINT32_MAX
> +
> /*
> * Reference for the LUKS format implemented here is
> *
> @@ -136,6 +138,13 @@ struct QCryptoBlockLUKS {
> };
>
>
> +static inline uint32_t
> +qcrypto_block_luks_payload_offset(uint32_t sector)
> +{
> + return sector == INVALID_SECTOR_OFFSET ? 0 :
> + sector * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
> +}
> +
> static int qcrypto_block_luks_cipher_name_lookup(const char *name,
> QCryptoCipherMode mode,
> uint32_t key_bytes,
> @@ -1255,8 +1264,8 @@ qcrypto_block_luks_open(QCryptoBlock *block,
> }
>
> block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
> - block->payload_offset = luks->header.payload_offset_sector *
> - block->sector_size;
> + block->payload_offset =
> +
> qcrypto_block_luks_payload_offset(luks->header.payload_offset_sector);
>
> return 0;
>
> @@ -1529,16 +1538,28 @@ qcrypto_block_luks_create(QCryptoBlock *block,
> slot->stripes = QCRYPTO_BLOCK_LUKS_STRIPES;
> }
>
> - /* The total size of the LUKS headers is the partition header + key
> - * slot headers, rounded up to the nearest sector, combined with
> - * the size of each master key material region, also rounded up
> - * to the nearest sector */
> - luks->header.payload_offset_sector = header_sectors +
> - QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS * split_key_sectors;
> + if (block->detached_header) {
> + /*
> + * Set the payload_offset_sector to a value that is nearly never
> + * reached in order to mark it as invalid and indicate that 0 should
> + * be the offset of the read/write operation on the 'file' protocol
> + * blockdev node. Here the UINT32_MAX is choosed
> + */
> + luks->header.payload_offset_sector = INVALID_SECTOR_OFFSET;
We should be setting payload offset to 0 when using a detached header
to match behaviour of 'cryptsetup' tools.
> + } else {
> + /*
> + * The total size of the LUKS headers is the partition header + key
> + * slot headers, rounded up to the nearest sector, combined with
> + * the size of each master key material region, also rounded up
> + * to the nearest sector
> + */
> + luks->header.payload_offset_sector = header_sectors +
> + QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS * split_key_sectors;
> + }
>
> block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
> - block->payload_offset = luks->header.payload_offset_sector *
> - block->sector_size;
> + block->payload_offset =
> +
> qcrypto_block_luks_payload_offset(luks->header.payload_offset_sector);
>
> /* Reserve header space to match payload offset */
> initfunc(block, block->payload_offset, opaque, &local_err);
> --
> 2.39.1
>
With regards,
Daniel
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