On Tue, Sep 06, 2022 at 09:41:38AM +0100, Daniel P. Berrangé wrote:
> Although the LUKS stripes are encoded in the keyslot header and so
> potentially configurable, in pratice the cryptsetup impl mandates
> this has the fixed value 4000. To avoid incompatibility apply the
> same enforcement in QEMU too. This also caps the memory usage for
> key material when QEMU tries to open a LUKS volume.
>
> Signed-off-by: Daniel P. Berrangé <berra...@redhat.com>
> ---
> crypto/block-luks.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/crypto/block-luks.c b/crypto/block-luks.c
> index 27d1b34c1d..81744e2a8e 100644
> --- a/crypto/block-luks.c
> +++ b/crypto/block-luks.c
> @@ -582,8 +582,9 @@ qcrypto_block_luks_check_header(const QCryptoBlockLUKS
> *luks, Error **errp)
> header_sectors,
> slot1->stripes);
>
> - if (slot1->stripes == 0) {
> - error_setg(errp, "Keyslot %zu is corrupted (stripes == 0)", i);
> + if (slot1->stripes != QCRYPTO_BLOCK_LUKS_STRIPES) {
> + error_setg(errp, "Keyslot %zu is corrupted (stripes %d != %d)",
> + i, slot1->stripes, QCRYPTO_BLOCK_LUKS_STRIPES);
> return -1;
> }
In nbdkit I decided to just check that this number < 10000, but I
agree that the only important implementation (the kernel) always fixes
this at 4000 (cryptsetup.git/lib/keymanage.c), so:
Reviewed-by: Richard W.M. Jones <rjo...@redhat.com>
Rich.
--
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