diff options
Diffstat (limited to 'Documentation/admin-guide/device-mapper/dm-integrity.rst')
| -rw-r--r-- | Documentation/admin-guide/device-mapper/dm-integrity.rst | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/Documentation/admin-guide/device-mapper/dm-integrity.rst b/Documentation/admin-guide/device-mapper/dm-integrity.rst index 2cc5488acbd9..8db172efa272 100644 --- a/Documentation/admin-guide/device-mapper/dm-integrity.rst +++ b/Documentation/admin-guide/device-mapper/dm-integrity.rst @@ -143,8 +143,8 @@ recalculate journal_crypt:algorithm(:key) (the key is optional) Encrypt the journal using given algorithm to make sure that the attacker can't read the journal. You can use a block cipher here - (such as "cbc(aes)") or a stream cipher (for example "chacha20", - "salsa20" or "ctr(aes)"). + (such as "cbc(aes)") or a stream cipher (for example "chacha20" + or "ctr(aes)"). The journal contains history of last writes to the block device, an attacker reading the journal could see the last sector numbers @@ -186,6 +186,17 @@ fix_padding space-efficient. If this option is not present, large padding is used - that is for compatibility with older kernels. +fix_hmac + Improve security of internal_hash and journal_mac: + + - the section number is mixed to the mac, so that an attacker can't + copy sectors from one journal section to another journal section + - the superblock is protected by journal_mac + - a 16-byte salt stored in the superblock is mixed to the mac, so + that the attacker can't detect that two disks have the same hmac + key and also to disallow the attacker to move sectors from one + disk to another + legacy_recalculate Allow recalculating of volumes with HMAC keys. This is disabled by default for security reasons - an attacker could modify the volume, |