What were you trying to do that didn't work?

Customer is asking that GCM be allowed as a key-cipher to encrypt the LUKS master key such that Red Hat Enterprise Linux with Full Disk Encryption is fully "Common Criteria" compliant.

REFERENCE: "Common Criteria Full Disk Encryption - Protection Profile:

https://www.commoncriteriaportal.org/files/ppfiles/CPP_FDE_EE_V2.0E.pdf

EXAMPLE: luks header information showing XTS is being used for key encryption, we need to be able

cryptsetup luksDump /dev/sda4

LUKS header information
Version: 2
Epoch: 6
Metadata area: 16384 [bytes]
Keyslots area: 16744448 [bytes]
UUID: 76a0701f-3ee5-45bc-8438-dc48d934051b
Label: (no label)
Subsystem: (no subsystem)
Flags: (no flags)

Data segments:
0: crypt
offset: 16777216 [bytes]
length: (whole device)
cipher: aes-xts-plain64 <-----------------AES in XTS mode for data, OK
sector: 512 [bytes]

Keyslots:
0: luks2
Key: 512 bits
Priority: normal
Cipher: aes-xts-plain64 <---------------- AES in XTS mode for key wrap, NOT OK
Cipher key: 512 bits
PBKDF: pbkdf2
Hash: sha256

Please provide the package NVR for which bug is seen:

cryptsetup

How reproducible:

Always. Encrypting a block device using GCM fails with:

Steps to reproduce

1. Create a new disk
2. Attempt to encrypt with:
   cryptsetup luksFormat --debug --cipher aes-xts-essiv:sha256 --keyslot-cipher=aes-gcm-essiv:sha256 --keyslot-key-size 256 -v -q vaultfile.img keyfile

Expected results

Expect we should be able to encrypt the LUKS master key with GCM.

Actual results

Command failed with code -1 (wrong or missing parameters).
um:e95f4658c88a41c8876d72c18af414ff3c5f04a616cd47f598a43dcefe85764d (in-memory)
Trying to read secondary LUKS2 header at offset 0x4000.
Reusing open ro fd on device vaultfile.img
LUKS2 header version 2 of size 16384 bytes, checksum
sha256.Checksum:ec02992e6358a6f138749bb42c8f7675b660b54462401b1b5edfd1e0a0 d9058b
e(on-disk)Checksum:ec02992e6358a6f138749bb42c8f7675b660b54462401b1b5edfd1e0a0d9058b
(in-memory)
Device size 31457280, offset 16777216.
Device vaultfile.img READ lock released.
Existing 'crypto_LUKS' superblock signature on device vaultfile.img will be wiped.
Existing 'crypto_LUKS' superblock signature on device vaultfile.img will be wiped.
Releasing crypt device vaultfile.img context.
Releasing device-mapper backend.
Closing read only fd for vaultfile.img.
Closing read write fd for vaultfile.img.
Unlocking memory.
Command failed with code -1 (wrong or missing parameters).