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 KEYS_COMPAT 24 def_bool y 25 depends on COMPAT && KEYS 26 27config PERSISTENT_KEYRINGS 28 bool "Enable register of persistent per-UID keyrings" 29 depends on KEYS 30 help 31 This option provides a register of persistent per-UID keyrings, 32 primarily aimed at Kerberos key storage. The keyrings are persistent 33 in the sense that they stay around after all processes of that UID 34 have exited, not that they survive the machine being rebooted. 35 36 A particular keyring may be accessed by either the user whose keyring 37 it is or by a process with administrative privileges. The active 38 LSMs gets to rule on which admin-level processes get to access the 39 cache. 40 41 Keyrings are created and added into the register upon demand and get 42 removed if they expire (a default timeout is set upon creation). 43 44config BIG_KEYS 45 bool "Large payload keys" 46 depends on KEYS 47 depends on TMPFS 48 select CRYPTO_AES 49 select CRYPTO_GCM 50 help 51 This option provides support for holding large keys within the kernel 52 (for example Kerberos ticket caches). The data may be stored out to 53 swapspace by tmpfs. 54 55 If you are unsure as to whether this is required, answer N. 56 57config TRUSTED_KEYS 58 tristate "TRUSTED KEYS" 59 depends on KEYS && TCG_TPM 60 select CRYPTO 61 select CRYPTO_HMAC 62 select CRYPTO_SHA1 63 select CRYPTO_HASH_INFO 64 help 65 This option provides support for creating, sealing, and unsealing 66 keys in the kernel. Trusted keys are random number symmetric keys, 67 generated and RSA-sealed by the TPM. The TPM only unseals the keys, 68 if the boot PCRs and other criteria match. Userspace will only ever 69 see encrypted blobs. 70 71 If you are unsure as to whether this is required, answer N. 72 73config ENCRYPTED_KEYS 74 tristate "ENCRYPTED KEYS" 75 depends on KEYS 76 select CRYPTO 77 select CRYPTO_HMAC 78 select CRYPTO_AES 79 select CRYPTO_CBC 80 select CRYPTO_SHA256 81 select CRYPTO_RNG 82 help 83 This option provides support for create/encrypting/decrypting keys 84 in the kernel. Encrypted keys are kernel generated random numbers, 85 which are encrypted/decrypted with a 'master' symmetric key. The 86 'master' key can be either a trusted-key or user-key type. 87 Userspace only ever sees/stores encrypted blobs. 88 89 If you are unsure as to whether this is required, answer N. 90 91config KEY_DH_OPERATIONS 92 bool "Diffie-Hellman operations on retained keys" 93 depends on KEYS 94 select CRYPTO 95 select CRYPTO_HASH 96 select CRYPTO_DH 97 help 98 This option provides support for calculating Diffie-Hellman 99 public keys and shared secrets using values stored as keys 100 in the kernel. 101 102 If you are unsure as to whether this is required, answer N. 103