| Message ID | 20190814202219.1870-5-mlevitsk@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | RFC: luks/encrypted qcow2 key management | expand |
On Wed, Aug 14, 2019 at 11:22:10PM +0300, Maxim Levitsky wrote: > Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> > --- > crypto/block-luks.c | 64 +++++++++++++++++++++++++++------------------ > 1 file changed, 38 insertions(+), 26 deletions(-) > > diff --git a/crypto/block-luks.c b/crypto/block-luks.c > index 6bb369f3b4..e1a4df94b7 100644 > --- a/crypto/block-luks.c > +++ b/crypto/block-luks.c > @@ -417,6 +417,33 @@ static int masterkeylen(QCryptoBlockLUKS *luks) > } > > > +/* > + * Returns number of sectors needed to store the key material > + * given number of anti forensic stripes > + */ > +static int splitkeylen_sectors(QCryptoBlockLUKS *luks, int stripes) Needs a qcrypto_block_luks_ prefix on method name. I'd also put 'static int' on a separate line from method name to reduce too long lines. > + > +{ > + /* > + * 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; Following line indent should only be 4 spaces > + > + size_t splitkeylen = masterkeylen(luks) * stripes; > + > + /* First align the key material size to block size*/ > + size_t splitkeylen_sectors = > + DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE); Again 4 space indent. > + > + /* 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 > */ > @@ -1169,7 +1196,7 @@ qcrypto_block_luks_create(QCryptoBlock *block, > QCryptoBlockCreateOptionsLUKS luks_opts; > Error *local_err = NULL; > uint8_t *masterkey = NULL; > - size_t splitkeylen = 0; > + size_t next_sector; > size_t i; > char *password; > const char *cipher_alg; > @@ -1388,23 +1415,16 @@ qcrypto_block_luks_create(QCryptoBlock *block, > goto error; > } > > + /* start with the sector that follows the header*/ > + next_sector = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / > + QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; I'd suggest 'post_header_sector' > > - /* Although LUKS has multiple key slots, we're just going > - * to use the first key slot */ > - splitkeylen = luks->header.key_bytes * 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; > - > - /* This calculation doesn't match that shown in the spec, > - * but instead follows the cryptsetup implementation. > - */ > - luks->header.key_slots[i].key_offset = > - (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); > + QCryptoBlockLUKSKeySlot *slot = &luks->header.key_slots[i]; > + slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; > + slot->key_offset = next_sector; > + slot->stripes = QCRYPTO_BLOCK_LUKS_STRIPES; > + next_sector += splitkeylen_sectors(luks, QCRYPTO_BLOCK_LUKS_STRIPES); I'm not a fan of the next_sector accumulator . I'd prefer to see the '* i' part done in splitkeylen_sectors, so that we have slot->key_offset = post_header_sector + splitkeylen_sectors(luks, QCRYPTO_BLOCK_LUKS_STRIPES, i); > @@ -1412,17 +1432,9 @@ qcrypto_block_luks_create(QCryptoBlock *block, > * 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 = > - (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 = next_sector; luks->header.payload_offset = post_header_sector + splitkeylen_sectors(luks, QCRYPTO_BLOCK_LUKS_STRIPES, QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); > block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; > - block->payload_offset = luks->header.payload_offset * > - block->sector_size; > + block->payload_offset = luks->header.payload_offset * block->sector_size; This is reverting a whitspace change done in previous method Regards, Daniel
On Thu, 2019-08-22 at 11:47 +0100, Daniel P. Berrangé wrote: > On Wed, Aug 14, 2019 at 11:22:10PM +0300, Maxim Levitsky wrote: > > Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> > > --- > > crypto/block-luks.c | 64 +++++++++++++++++++++++++++------------------ > > 1 file changed, 38 insertions(+), 26 deletions(-) > > > > diff --git a/crypto/block-luks.c b/crypto/block-luks.c > > index 6bb369f3b4..e1a4df94b7 100644 > > --- a/crypto/block-luks.c > > +++ b/crypto/block-luks.c > > @@ -417,6 +417,33 @@ static int masterkeylen(QCryptoBlockLUKS *luks) > > } > > > > > > +/* > > + * Returns number of sectors needed to store the key material > > + * given number of anti forensic stripes > > + */ > > +static int splitkeylen_sectors(QCryptoBlockLUKS *luks, int stripes) > > Needs a qcrypto_block_luks_ prefix on method name. Done. > > I'd also put 'static int' on a separate line from method name > to reduce too long lines. Done. > > > + > > +{ > > + /* > > + * 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; > > Following line indent should only be 4 spaces I didn't knew that. Fixed. > > > + > > + size_t splitkeylen = masterkeylen(luks) * stripes; > > + > > + /* First align the key material size to block size*/ > > + size_t splitkeylen_sectors = > > + DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE); > > Again 4 space indent. > > > + > > + /* 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 > > */ > > @@ -1169,7 +1196,7 @@ qcrypto_block_luks_create(QCryptoBlock *block, > > QCryptoBlockCreateOptionsLUKS luks_opts; > > Error *local_err = NULL; > > uint8_t *masterkey = NULL; > > - size_t splitkeylen = 0; > > + size_t next_sector; > > size_t i; > > char *password; > > const char *cipher_alg; > > @@ -1388,23 +1415,16 @@ qcrypto_block_luks_create(QCryptoBlock *block, > > goto error; > > } > > > > + /* start with the sector that follows the header*/ > > + next_sector = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / > > + QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; > > I'd suggest 'post_header_sector' I called it now header_sectors, and each split key, split_key_sectors. I hope that this is good enough. > > > > > - /* Although LUKS has multiple key slots, we're just going > > - * to use the first key slot */ > > - splitkeylen = luks->header.key_bytes * 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; > > - > > - /* This calculation doesn't match that shown in the spec, > > - * but instead follows the cryptsetup implementation. > > - */ > > - luks->header.key_slots[i].key_offset = > > - (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); > > + QCryptoBlockLUKSKeySlot *slot = &luks->header.key_slots[i]; > > + slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; > > + slot->key_offset = next_sector; > > + slot->stripes = QCRYPTO_BLOCK_LUKS_STRIPES; > > + next_sector += splitkeylen_sectors(luks, QCRYPTO_BLOCK_LUKS_STRIPES); > > I'm not a fan of the next_sector accumulator . I actually think that accumulator is cleaner here, but I won't argue about this. Fixed. > > I'd prefer to see the '* i' part done in splitkeylen_sectors, so that > we have > > slot->key_offset = post_header_sector + > splitkeylen_sectors(luks, QCRYPTO_BLOCK_LUKS_STRIPES, i); > > > @@ -1412,17 +1432,9 @@ qcrypto_block_luks_create(QCryptoBlock *block, > > * 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 = > > - (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 = next_sector; > > luks->header.payload_offset = post_header_sector + > splitkeylen_sectors(luks, QCRYPTO_BLOCK_LUKS_STRIPES, > QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); > > > > block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; > > - block->payload_offset = luks->header.payload_offset * > > - block->sector_size; > > + block->payload_offset = luks->header.payload_offset * block->sector_size; > > > This is reverting a whitspace change done in previous method True. Fixed. > > Regards, > Daniel Best regards, Maxim Levitsky
diff --git a/crypto/block-luks.c b/crypto/block-luks.c index 6bb369f3b4..e1a4df94b7 100644 --- a/crypto/block-luks.c +++ b/crypto/block-luks.c @@ -417,6 +417,33 @@ static int masterkeylen(QCryptoBlockLUKS *luks) } +/* + * Returns number of sectors needed to store the key material + * given number of anti forensic stripes + */ +static int splitkeylen_sectors(QCryptoBlockLUKS *luks, 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; + + size_t splitkeylen = masterkeylen(luks) * 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 */ @@ -1169,7 +1196,7 @@ qcrypto_block_luks_create(QCryptoBlock *block, QCryptoBlockCreateOptionsLUKS luks_opts; Error *local_err = NULL; uint8_t *masterkey = NULL; - size_t splitkeylen = 0; + size_t next_sector; size_t i; char *password; const char *cipher_alg; @@ -1388,23 +1415,16 @@ qcrypto_block_luks_create(QCryptoBlock *block, goto error; } + /* start with the sector that follows the header*/ + next_sector = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / + QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; - /* Although LUKS has multiple key slots, we're just going - * to use the first key slot */ - splitkeylen = luks->header.key_bytes * 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; - - /* This calculation doesn't match that shown in the spec, - * but instead follows the cryptsetup implementation. - */ - luks->header.key_slots[i].key_offset = - (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); + QCryptoBlockLUKSKeySlot *slot = &luks->header.key_slots[i]; + slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; + slot->key_offset = next_sector; + slot->stripes = QCRYPTO_BLOCK_LUKS_STRIPES; + next_sector += splitkeylen_sectors(luks, QCRYPTO_BLOCK_LUKS_STRIPES); } @@ -1412,17 +1432,9 @@ qcrypto_block_luks_create(QCryptoBlock *block, * 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 = - (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 = next_sector; block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; - block->payload_offset = luks->header.payload_offset * - block->sector_size; + block->payload_offset = luks->header.payload_offset * block->sector_size; /* Reserve header space to match payload offset */ initfunc(block, block->payload_offset, opaque, &local_err);
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> --- crypto/block-luks.c | 64 +++++++++++++++++++++++++++------------------ 1 file changed, 38 insertions(+), 26 deletions(-)