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crypto: split off helpers for converting LUKS header endianess

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The unit test suite is shortly going to want to convert header
endianness separately from the main I/O functions.

Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This commit is contained in:
Daniel P. Berrangé 2022-05-10 15:40:55 +01:00
parent 36445acebd
commit 98c72dfb71
2 changed files with 53 additions and 32 deletions
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6
crypto/block-luks-priv.h
View file

@ -135,3 +135,9 @@ struct QCryptoBlockLUKSHeader {
/* key slots */
QCryptoBlockLUKSKeySlot key_slots[QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS];
};
void
qcrypto_block_luks_to_disk_endian(QCryptoBlockLUKSHeader *hdr);
void
qcrypto_block_luks_from_disk_endian(QCryptoBlockLUKSHeader *hdr);

79
crypto/block-luks.c
View file

@ -348,6 +348,51 @@ qcrypto_block_luks_splitkeylen_sectors(const QCryptoBlockLUKS *luks,
return ROUND_UP(splitkeylen_sectors, header_sectors);
}
void
qcrypto_block_luks_to_disk_endian(QCryptoBlockLUKSHeader *hdr)
{
size_t i;
/*
* Everything on disk uses Big Endian (tm), so flip header fields
* before writing them
*/
cpu_to_be16s(&hdr->version);
cpu_to_be32s(&hdr->payload_offset_sector);
cpu_to_be32s(&hdr->master_key_len);
cpu_to_be32s(&hdr->master_key_iterations);
for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
cpu_to_be32s(&hdr->key_slots[i].active);
cpu_to_be32s(&hdr->key_slots[i].iterations);
cpu_to_be32s(&hdr->key_slots[i].key_offset_sector);
cpu_to_be32s(&hdr->key_slots[i].stripes);
}
}
void
qcrypto_block_luks_from_disk_endian(QCryptoBlockLUKSHeader *hdr)
{
size_t i;
/*
* The header is always stored in big-endian format, so
* convert everything to native
*/
be16_to_cpus(&hdr->version);
be32_to_cpus(&hdr->payload_offset_sector);
be32_to_cpus(&hdr->master_key_len);
be32_to_cpus(&hdr->master_key_iterations);
for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
be32_to_cpus(&hdr->key_slots[i].active);
be32_to_cpus(&hdr->key_slots[i].iterations);
be32_to_cpus(&hdr->key_slots[i].key_offset_sector);
be32_to_cpus(&hdr->key_slots[i].stripes);
}
}
/*
* Stores the main LUKS header, taking care of endianess
*/
@ -359,28 +404,13 @@ qcrypto_block_luks_store_header(QCryptoBlock *block,
{
const QCryptoBlockLUKS *luks = block->opaque;
Error *local_err = NULL;
size_t i;
g_autofree QCryptoBlockLUKSHeader *hdr_copy = NULL;
/* Create a copy of the header */
hdr_copy = g_new0(QCryptoBlockLUKSHeader, 1);
memcpy(hdr_copy, &luks->header, sizeof(QCryptoBlockLUKSHeader));
/*
* Everything on disk uses Big Endian (tm), so flip header fields
* before writing them
*/
cpu_to_be16s(&hdr_copy->version);
cpu_to_be32s(&hdr_copy->payload_offset_sector);
cpu_to_be32s(&hdr_copy->master_key_len);
cpu_to_be32s(&hdr_copy->master_key_iterations);
for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
cpu_to_be32s(&hdr_copy->key_slots[i].active);
cpu_to_be32s(&hdr_copy->key_slots[i].iterations);
cpu_to_be32s(&hdr_copy->key_slots[i].key_offset_sector);
cpu_to_be32s(&hdr_copy->key_slots[i].stripes);
}
qcrypto_block_luks_to_disk_endian(hdr_copy);
/* Write out the partition header and key slot headers */
writefunc(block, 0, (const uint8_t *)hdr_copy, sizeof(*hdr_copy),
@ -404,7 +434,6 @@ qcrypto_block_luks_load_header(QCryptoBlock *block,
Error **errp)
{
int rv;
size_t i;
QCryptoBlockLUKS *luks = block->opaque;
/*
@ -420,21 +449,7 @@ qcrypto_block_luks_load_header(QCryptoBlock *block,
return rv;
}
/*
* The header is always stored in big-endian format, so
* convert everything to native
*/
be16_to_cpus(&luks->header.version);
be32_to_cpus(&luks->header.payload_offset_sector);
be32_to_cpus(&luks->header.master_key_len);
be32_to_cpus(&luks->header.master_key_iterations);
for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
be32_to_cpus(&luks->header.key_slots[i].active);
be32_to_cpus(&luks->header.key_slots[i].iterations);
be32_to_cpus(&luks->header.key_slots[i].key_offset_sector);
be32_to_cpus(&luks->header.key_slots[i].stripes);
}
qcrypto_block_luks_from_disk_endian(&luks->header);
return 0;
}