On Fri, 2019-09-06 at 14:17 +0100, Daniel P. Berrangé wrote:
> On Mon, Aug 26, 2019 at 04:51:01PM +0300, Maxim Levitsky wrote:
> > Signed-off-by: Maxim Levitsky <mlevi...@redhat.com>
> > ---
> > crypto/block-luks.c | 64 +++++++++++++++++++++++++++++----------------
> > 1 file changed, 41 insertions(+), 23 deletions(-)
> >
> > diff --git a/crypto/block-luks.c b/crypto/block-luks.c
> > index d713125925..6a43d97ce5 100644
> > --- a/crypto/block-luks.c
> > +++ b/crypto/block-luks.c
> > @@ -409,6 +409,32 @@ qcrypto_block_luks_essiv_cipher(QCryptoCipherAlgorithm
> > cipher,
> > }
> > }
> >
> > +/*
> > + * Returns number of sectors needed to store the key material
> > + * given number of anti forensic stripes
> > + */
> > +static int
> > +qcrypto_block_luks_splitkeylen_sectors(const QCryptoBlockLUKS *luks,
> > + unsigned int stripes)
> > +{
> > + /*
> > + * This calculation doesn't match that shown in the spec,
> > + * but instead follows the cryptsetup implementation.
> > + */
> > +
> > + size_t header_sectors = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
> > + QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
>
> The caller already calculated that so just pass it in
All right, no problem.
>
> > +
> > + size_t splitkeylen = luks->header.master_key_len * stripes;
> > +
> > + /* First align the key material size to block size*/
> > + size_t splitkeylen_sectors =
> > + DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE);
> > +
> > + /* Then also align the key material size to the size of the header */
> > + return ROUND_UP(splitkeylen_sectors, header_sectors);
> > +}
> > +
> > /*
> > * Stores the main LUKS header, taking care of endianess
> > */
> > @@ -1151,7 +1177,8 @@ qcrypto_block_luks_create(QCryptoBlock *block,
> > QCryptoBlockCreateOptionsLUKS luks_opts;
> > Error *local_err = NULL;
> > g_autofree uint8_t *masterkey = NULL;
> > - size_t splitkeylen = 0;
> > + size_t header_sectors;
> > + size_t split_key_sectors;
> > size_t i;
> > g_autofree char *password;
> > const char *cipher_alg;
> > @@ -1370,37 +1397,28 @@ qcrypto_block_luks_create(QCryptoBlock *block,
> > goto error;
> > }
> >
> > + /* start with the sector that follows the header*/
> > + header_sectors = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
> > + QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
> > +
> > + split_key_sectors =
> > + qcrypto_block_luks_splitkeylen_sectors(luks,
> > + QCRYPTO_BLOCK_LUKS_STRIPES);
> >
> > - /* Although LUKS has multiple key slots, we're just going
> > - * to use the first key slot */
> > - splitkeylen = luks->header.master_key_len * QCRYPTO_BLOCK_LUKS_STRIPES;
> > for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
> > - luks->header.key_slots[i].active =
> > QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED;
> > - luks->header.key_slots[i].stripes = QCRYPTO_BLOCK_LUKS_STRIPES;
> > + QCryptoBlockLUKSKeySlot *slot = &luks->header.key_slots[i];
> > + slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED;
> >
> > - /* This calculation doesn't match that shown in the spec,
> > - * but instead follows the cryptsetup implementation.
> > - */
> > - luks->header.key_slots[i].key_offset_sector =
> > - (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
> > - QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) +
> > - (ROUND_UP(DIV_ROUND_UP(splitkeylen,
> > QCRYPTO_BLOCK_LUKS_SECTOR_SIZE),
> > - (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
> > - QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * i);
> > + slot->key_offset_sector = header_sectors + i * split_key_sectors;
> > + 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 =
> > - (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
> > - QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) +
> > - (ROUND_UP(DIV_ROUND_UP(splitkeylen,
> > QCRYPTO_BLOCK_LUKS_SECTOR_SIZE),
> > - (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
> > - QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) *
> > - QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
> > + 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 *
>
> Reviewed-by: Daniel P. Berrangé <berra...@redhat.com>
>
> Regards,
> Daniel
Best regards,
Maxim Levitsky
