# # Key management configuration # config KEYS bool "Enable access key retention support" select ASSOCIATIVE_ARRAY 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 KEYS_COMPAT def_bool y depends on COMPAT && KEYS config PERSISTENT_KEYRINGS bool "Enable register of persistent per-UID keyrings" depends on KEYS 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. A 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 BIG_KEYS bool "Large payload keys" depends on KEYS depends on TMPFS select CRYPTO select CRYPTO_AES select CRYPTO_GCM 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 TRUSTED_KEYS tristate "TRUSTED KEYS" depends on KEYS && TCG_TPM select CRYPTO select CRYPTO_HMAC select CRYPTO_SHA1 select CRYPTO_HASH_INFO 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 ENCRYPTED_KEYS tristate "ENCRYPTED KEYS" depends on KEYS select CRYPTO select CRYPTO_HMAC select CRYPTO_AES select CRYPTO_CBC select CRYPTO_SHA256 select CRYPTO_RNG 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 KEY_DH_OPERATIONS bool "Diffie-Hellman operations on retained keys" depends on KEYS select CRYPTO select CRYPTO_HASH select CRYPTO_DH 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.