Bug 2193342

Summary:	LUKS devices created during installation in FIPS mode use argon2i derivation function
Product:	Red Hat Enterprise Linux 8	Reporter:	Jan Stodola <jstodola>
Component:	cryptsetup	Assignee:	Daniel Zaťovič <dzatovic>
Status:	VERIFIED ---	QA Contact:	guazhang <guazhang>
Severity:	medium	Docs Contact:
Priority:	high
Version:	8.8	CC:	agk, guazhang, jbrassow, okozina, prajnoha, ssorce
Target Milestone:	rc	Keywords:	Triaged
Target Release:	8.9
Hardware:	Unspecified
OS:	Unspecified
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Fixed In Version:	cryptsetup-2.3.7-7.el8	Doc Type:	If docs needed, set a value
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Last Closed:		Type:	Bug
Regression:	---	Mount Type:	---
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Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Jan Stodola 2023-05-05 10:18:23 UTC

Description of problem:
When installing a system in FIPS mode and creating LUKS devices, the installer creates LUKS devices having the argon2i key derivation function. pbkdf2 should be used instead in FIPS mode (see bug 1584710).

Version-Release number of selected component (if applicable):
cryptsetup-2.3.7-5.el8 from RHEL-8.8, but the same problem exists since RHEL-8.0 (cryptsetup-2.0.6-1.el8.x86_64.rpm)

How reproducible:
Always

Steps to Reproduce:
1. Start the installation in FIPS mode (with "fips=1" on the kernel cmdline)
2. Let anaconda create an encrypted partition
3. Check the created encrypted partition

Actual results:
[anaconda root@localhost ~]# cryptsetup luksDump /dev/vda2 
LUKS header information
Version:        2
Epoch:          3
Metadata area:  16384 [bytes]
Keyslots area:  16744448 [bytes]
UUID:           3f8d5702-92fd-4c85-80c2-341b292610c6
Label:          (no label)
Subsystem:      (no subsystem)
Flags:          (no flags)

Data segments:
  0: crypt
        offset: 16777216 [bytes]
        length: (whole device)
        cipher: aes-xts-plain64
        sector: 512 [bytes]

Keyslots:
  0: luks2
        Key:        512 bits
        Priority:   normal
        Cipher:     aes-xts-plain64
        Cipher key: 512 bits
        PBKDF:      argon2i
        Time cost:  4
        Memory:     1048576
        Threads:    2
...


Expected results:
PBKDF:   pbkdf2

Additional info:
* There is no /etc/system-fips in the installation environment in FIPS mode.
* Manually creating an empty /etc/system-fips file in the installation environment is a workaround for the installer to create LUKS devices with pbkdf2
* The same problem exists in the installation environment when running cryptsetup manually, like cryptsetup luksFormat $device.
* This is not a problem on the installed system, since /etc/system-fips exists there in FIPS mode.

Comment 4 Ondrej Kozina 2023-05-11 09:48:17 UTC

After the installation it can be fixed by running following command:

cryptsetup luksConvertKey -S<keyslot_id> /dev/vda2

The command above will change pbkdf parameters to appropriate default values (pbkdf2 function, targeting 2 seconds unlock time if system runs in FIPS mode) for keyslot identified by <keyslot_id>. The keyslot binary area is overwritten with new data containing same volume key but it will be protected by new KEK derived from passphrase using pbkdf2 function.