# SPDX-License-Identifier: GPL-2.0-only
#
# Key management configuration
#
config [31mCONFIG_KEYS[0m
bool "Enable access key retention support"
select [31mCONFIG_ASSOCIATIVE_ARRAY[0m
help
This option provides support for retaining authentication tokens and
access keys in the kernel.
It also includes provision of methods by which such keys might be
associated with a process so that network filesystems, encryption
support and the like can find them.
Furthermore, a special type of key is available that acts as keyring:
a searchable sequence of keys. Each process is equipped with access
to five standard keyrings: UID-specific, GID-specific, session,
process and thread.
If you are unsure as to whether this is required, answer N.
config [31mCONFIG_KEYS_COMPAT[0m
def_bool y
depends on [31mCONFIG_COMPAT[0m && [31mCONFIG_KEYS[0m
config [31mCONFIG_KEYS_REQUEST_CACHE[0m
bool "Enable temporary caching of the last request_key() result"
depends on [31mCONFIG_KEYS[0m
help
This option causes the result of the last successful request_key()
call that didn't upcall to the kernel to be cached temporarily in the
task_struct. The cache is cleared by exit and just prior to the
resumption of userspace.
This allows the key used for multiple step processes where each step
wants to request a key that is likely the same as the one requested
by the last step to save on the searching.
An example of such a process is a pathwalk through a network
filesystem in which each method needs to request an authentication
key. Pathwalk will call multiple methods for each dentry traversed
(permission, d_revalidate, lookup, getxattr, getacl, ...).
config [31mCONFIG_PERSISTENT_KEYRINGS[0m
bool "Enable register of persistent per-UID keyrings"
depends on [31mCONFIG_KEYS[0m
help
This option provides a register of persistent per-UID keyrings,
primarily aimed at Kerberos key storage. The keyrings are persistent
in the sense that they stay around after all processes of that UID
have exited, not that they survive the machine being rebooted.
[31mCONFIG_A[0m particular keyring may be accessed by either the user whose keyring
it is or by a process with administrative privileges. The active
LSMs gets to rule on which admin-level processes get to access the
cache.
Keyrings are created and added into the register upon demand and get
removed if they expire (a default timeout is set upon creation).
config [31mCONFIG_BIG_KEYS[0m
bool "Large payload keys"
depends on [31mCONFIG_KEYS[0m
depends on [31mCONFIG_TMPFS[0m
select [31mCONFIG_CRYPTO[0m
select [31mCONFIG_CRYPTO_AES[0m
select [31mCONFIG_CRYPTO_GCM[0m
help
This option provides support for holding large keys within the kernel
(for example Kerberos ticket caches). The data may be stored out to
swapspace by tmpfs.
If you are unsure as to whether this is required, answer N.
config [31mCONFIG_TRUSTED_KEYS[0m
tristate "TRUSTED KEYS"
depends on [31mCONFIG_KEYS[0m && [31mCONFIG_TCG_TPM[0m
select [31mCONFIG_CRYPTO[0m
select [31mCONFIG_CRYPTO_HMAC[0m
select [31mCONFIG_CRYPTO_SHA1[0m
select [31mCONFIG_CRYPTO_HASH_INFO[0m
help
This option provides support for creating, sealing, and unsealing
keys in the kernel. Trusted keys are random number symmetric keys,
generated and RSA-sealed by the TPM. The TPM only unseals the keys,
if the boot PCRs and other criteria match. Userspace will only ever
see encrypted blobs.
If you are unsure as to whether this is required, answer N.
config [31mCONFIG_ENCRYPTED_KEYS[0m
tristate "ENCRYPTED KEYS"
depends on [31mCONFIG_KEYS[0m
select [31mCONFIG_CRYPTO[0m
select [31mCONFIG_CRYPTO_HMAC[0m
select [31mCONFIG_CRYPTO_AES[0m
select [31mCONFIG_CRYPTO_CBC[0m
select [31mCONFIG_CRYPTO_SHA256[0m
select [31mCONFIG_CRYPTO_RNG[0m
help
This option provides support for create/encrypting/decrypting keys
in the kernel. Encrypted keys are kernel generated random numbers,
which are encrypted/decrypted with a 'master' symmetric key. The
'master' key can be either a trusted-key or user-key type.
Userspace only ever sees/stores encrypted blobs.
If you are unsure as to whether this is required, answer N.
config [31mCONFIG_KEY_DH_OPERATIONS[0m
bool "Diffie-Hellman operations on retained keys"
depends on [31mCONFIG_KEYS[0m
select [31mCONFIG_CRYPTO[0m
select [31mCONFIG_CRYPTO_HASH[0m
select [31mCONFIG_CRYPTO_DH[0m
help
This option provides support for calculating Diffie-Hellman
public keys and shared secrets using values stored as keys
in the kernel.
If you are unsure as to whether this is required, answer N.