diff --git a/certs/system_keyring.c b/certs/system_keyring.c index a7a49b17ceb1..b348e0898d34 100644 --- a/certs/system_keyring.c +++ b/certs/system_keyring.c @@ -51,6 +51,26 @@ int restrict_link_by_builtin_trusted(struct key *dest_keyring, builtin_trusted_keys); } +/** + * restrict_link_by_digsig_builtin - Restrict digitalSignature key additions by the built-in keyring + * @dest_keyring: Keyring being linked to. + * @type: The type of key being added. + * @payload: The payload of the new key. + * @restriction_key: A ring of keys that can be used to vouch for the new cert. + * + * Restrict the addition of keys into a keyring based on the key-to-be-added + * being vouched for by a key in the built in system keyring. The new key + * must have the digitalSignature usage field set. + */ +int restrict_link_by_digsig_builtin(struct key *dest_keyring, + const struct key_type *type, + const union key_payload *payload, + struct key *restriction_key) +{ + return restrict_link_by_digsig(dest_keyring, type, payload, + builtin_trusted_keys); +} + #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING /** * restrict_link_by_builtin_and_secondary_trusted - Restrict keyring @@ -83,6 +103,35 @@ int restrict_link_by_builtin_and_secondary_trusted( secondary_trusted_keys); } +/** + * restrict_link_by_digsig_builtin_and_secondary - Restrict by digitalSignature. + * @dest_keyring: Keyring being linked to. + * @type: The type of key being added. + * @payload: The payload of the new key. + * @restrict_key: A ring of keys that can be used to vouch for the new cert. + * + * Restrict the addition of keys into a keyring based on the key-to-be-added + * being vouched for by a key in either the built-in or the secondary system + * keyrings. The new key must have the digitalSignature usage field set. + */ +int restrict_link_by_digsig_builtin_and_secondary(struct key *dest_keyring, + const struct key_type *type, + const union key_payload *payload, + struct key *restrict_key) +{ + /* If we have a secondary trusted keyring, then that contains a link + * through to the builtin keyring and the search will follow that link. + */ + if (type == &key_type_keyring && + dest_keyring == secondary_trusted_keys && + payload == &builtin_trusted_keys->payload) + /* Allow the builtin keyring to be added to the secondary */ + return 0; + + return restrict_link_by_digsig(dest_keyring, type, payload, + secondary_trusted_keys); +} + /* * Allocate a struct key_restriction for the "builtin and secondary trust" * keyring. Only for use in system_trusted_keyring_init(). diff --git a/crypto/asymmetric_keys/restrict.c b/crypto/asymmetric_keys/restrict.c index 276bdb627498..6b69ea40da23 100644 --- a/crypto/asymmetric_keys/restrict.c +++ b/crypto/asymmetric_keys/restrict.c @@ -148,6 +148,50 @@ int restrict_link_by_ca(struct key *dest_keyring, return 0; } +/** + * restrict_link_by_digsig - Restrict additions to a ring of digsig keys + * @dest_keyring: Keyring being linked to. + * @type: The type of key being added. + * @payload: The payload of the new key. + * @trust_keyring: A ring of keys that can be used to vouch for the new cert. + * + * Check if the new certificate has digitalSignature usage set. If it is, + * then mark the new certificate as being ok to link. Afterwards verify + * the new certificate against the ones in the trust_keyring. + * + * Returns 0 if the new certificate was accepted, -ENOKEY if the + * certificate is not a digsig. -ENOPKG if the signature uses unsupported + * crypto, or some other error if there is a matching certificate but + * the signature check cannot be performed. + */ +int restrict_link_by_digsig(struct key *dest_keyring, + const struct key_type *type, + const union key_payload *payload, + struct key *trust_keyring) +{ + const struct public_key *pkey; + + if (type != &key_type_asymmetric) + return -EOPNOTSUPP; + + pkey = payload->data[asym_crypto]; + + if (!pkey) + return -ENOPKG; + + if (!test_bit(KEY_EFLAG_DIGITALSIG, &pkey->key_eflags)) + return -ENOKEY; + + if (test_bit(KEY_EFLAG_CA, &pkey->key_eflags)) + return -ENOKEY; + + if (test_bit(KEY_EFLAG_KEYCERTSIGN, &pkey->key_eflags)) + return -ENOKEY; + + return restrict_link_by_signature(dest_keyring, type, payload, + trust_keyring); +} + static bool match_either_id(const struct asymmetric_key_id **pair, const struct asymmetric_key_id *single) { diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h index 8fadd561c50e..462f8a34cdf8 100644 --- a/include/crypto/public_key.h +++ b/include/crypto/public_key.h @@ -78,6 +78,10 @@ extern int restrict_link_by_ca(struct key *dest_keyring, const struct key_type *type, const union key_payload *payload, struct key *trust_keyring); +int restrict_link_by_digsig(struct key *dest_keyring, + const struct key_type *type, + const union key_payload *payload, + struct key *trust_keyring); #else static inline int restrict_link_by_ca(struct key *dest_keyring, const struct key_type *type, @@ -86,6 +90,14 @@ static inline int restrict_link_by_ca(struct key *dest_keyring, { return 0; } + +static inline int restrict_link_by_digsig(struct key *dest_keyring, + const struct key_type *type, + const union key_payload *payload, + struct key *trust_keyring) +{ + return 0; +} #endif extern int query_asymmetric_key(const struct kernel_pkey_params *, diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h index 91e080efb918..7e2583208820 100644 --- a/include/keys/system_keyring.h +++ b/include/keys/system_keyring.h @@ -23,10 +23,15 @@ extern int restrict_link_by_builtin_trusted(struct key *keyring, const struct key_type *type, const union key_payload *payload, struct key *restriction_key); +int restrict_link_by_digsig_builtin(struct key *dest_keyring, + const struct key_type *type, + const union key_payload *payload, + struct key *restriction_key); extern __init int load_module_cert(struct key *keyring); #else #define restrict_link_by_builtin_trusted restrict_link_reject +#define restrict_link_by_digsig_builtin restrict_link_reject static inline __init int load_module_cert(struct key *keyring) { @@ -41,8 +46,13 @@ extern int restrict_link_by_builtin_and_secondary_trusted( const struct key_type *type, const union key_payload *payload, struct key *restriction_key); +int restrict_link_by_digsig_builtin_and_secondary(struct key *keyring, + const struct key_type *type, + const union key_payload *payload, + struct key *restriction_key); #else #define restrict_link_by_builtin_and_secondary_trusted restrict_link_by_builtin_trusted +#define restrict_link_by_digsig_builtin_and_secondary restrict_link_by_digsig_builtin #endif #ifdef CONFIG_INTEGRITY_MACHINE_KEYRING