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 49 select CRYPTO_AES 50 select CRYPTO_GCM 51 help 52 This option provides support for holding large keys within the kernel 53 (for example Kerberos ticket caches). The data may be stored out to 54 swapspace by tmpfs. 55 56 If you are unsure as to whether this is required, answer N. 57 58config TRUSTED_KEYS 59 tristate "TRUSTED KEYS" 60 depends on KEYS && TCG_TPM 61 select CRYPTO 62 select CRYPTO_HMAC 63 select CRYPTO_SHA1 64 select CRYPTO_HASH_INFO 65 help 66 This option provides support for creating, sealing, and unsealing 67 keys in the kernel. Trusted keys are random number symmetric keys, 68 generated and RSA-sealed by the TPM. The TPM only unseals the keys, 69 if the boot PCRs and other criteria match. Userspace will only ever 70 see encrypted blobs. 71 72 If you are unsure as to whether this is required, answer N. 73 74config ENCRYPTED_KEYS 75 tristate "ENCRYPTED KEYS" 76 depends on KEYS 77 select CRYPTO 78 select CRYPTO_HMAC 79 select CRYPTO_AES 80 select CRYPTO_CBC 81 select CRYPTO_SHA256 82 select CRYPTO_RNG 83 help 84 This option provides support for create/encrypting/decrypting keys 85 in the kernel. Encrypted keys are kernel generated random numbers, 86 which are encrypted/decrypted with a 'master' symmetric key. The 87 'master' key can be either a trusted-key or user-key type. 88 Userspace only ever sees/stores encrypted blobs. 89 90 If you are unsure as to whether this is required, answer N. 91 92config KEY_DH_OPERATIONS 93 bool "Diffie-Hellman operations on retained keys" 94 depends on KEYS 95 select CRYPTO 96 select CRYPTO_HASH 97 select CRYPTO_DH 98 help 99 This option provides support for calculating Diffie-Hellman 100 public keys and shared secrets using values stored as keys 101 in the kernel. 102 103 If you are unsure as to whether this is required, answer N. 104