1# 2# Key management configuration 3# 4 5config KEYS 6 bool "Enable access key retention support" 7 select ASSOCIATIVE_ARRAY 8 help 9 This option provides support for retaining authentication tokens and 10 access keys in the kernel. 11 12 It also includes provision of methods by which such keys might be 13 associated with a process so that network filesystems, encryption 14 support and the like can find them. 15 16 Furthermore, a special type of key is available that acts as keyring: 17 a searchable sequence of keys. Each process is equipped with access 18 to five standard keyrings: UID-specific, GID-specific, session, 19 process and thread. 20 21 If you are unsure as to whether this is required, answer N. 22 23config PERSISTENT_KEYRINGS 24 bool "Enable register of persistent per-UID keyrings" 25 depends on KEYS 26 help 27 This option provides a register of persistent per-UID keyrings, 28 primarily aimed at Kerberos key storage. The keyrings are persistent 29 in the sense that they stay around after all processes of that UID 30 have exited, not that they survive the machine being rebooted. 31 32 A particular keyring may be accessed by either the user whose keyring 33 it is or by a process with administrative privileges. The active 34 LSMs gets to rule on which admin-level processes get to access the 35 cache. 36 37 Keyrings are created and added into the register upon demand and get 38 removed if they expire (a default timeout is set upon creation). 39 40config BIG_KEYS 41 bool "Large payload keys" 42 depends on KEYS 43 depends on TMPFS 44 help 45 This option provides support for holding large keys within the kernel 46 (for example Kerberos ticket caches). The data may be stored out to 47 swapspace by tmpfs. 48 49 If you are unsure as to whether this is required, answer N. 50 51config TRUSTED_KEYS 52 tristate "TRUSTED KEYS" 53 depends on KEYS && TCG_TPM 54 select CRYPTO 55 select CRYPTO_HMAC 56 select CRYPTO_SHA1 57 select CRYPTO_HASH_INFO 58 help 59 This option provides support for creating, sealing, and unsealing 60 keys in the kernel. Trusted keys are random number symmetric keys, 61 generated and RSA-sealed by the TPM. The TPM only unseals the keys, 62 if the boot PCRs and other criteria match. Userspace will only ever 63 see encrypted blobs. 64 65 If you are unsure as to whether this is required, answer N. 66 67config ENCRYPTED_KEYS 68 tristate "ENCRYPTED KEYS" 69 depends on KEYS 70 select CRYPTO 71 select CRYPTO_HMAC 72 select CRYPTO_AES 73 select CRYPTO_CBC 74 select CRYPTO_SHA256 75 select CRYPTO_RNG 76 help 77 This option provides support for create/encrypting/decrypting keys 78 in the kernel. Encrypted keys are kernel generated random numbers, 79 which are encrypted/decrypted with a 'master' symmetric key. The 80 'master' key can be either a trusted-key or user-key type. 81 Userspace only ever sees/stores encrypted blobs. 82 83 If you are unsure as to whether this is required, answer N. 84