diff options
Diffstat (limited to 'crypto/asymmetric_keys')
| -rw-r--r-- | crypto/asymmetric_keys/asymmetric_type.c | 31 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/restrict.c | 158 |
2 files changed, 144 insertions, 45 deletions
diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c index 72700ed81594..e4b0ed386bc8 100644 --- a/crypto/asymmetric_keys/asymmetric_type.c +++ b/crypto/asymmetric_keys/asymmetric_type.c @@ -496,20 +496,37 @@ static struct key_restriction *asymmetric_lookup_restriction( restrict_method = strsep(&next, ":"); if ((strcmp(restrict_method, "key_or_keyring") == 0) && next) { + char *key_text; key_serial_t serial; struct key *key; + key_restrict_link_func_t link_fn = + restrict_link_by_key_or_keyring; + bool allow_null_key = false; - if (kstrtos32(next, 0, &serial) < 0) - goto out; + key_text = strsep(&next, ":"); + + if (next) { + if (strcmp(next, "chain") != 0) + goto out; + + link_fn = restrict_link_by_key_or_keyring_chain; + allow_null_key = true; + } - key = key_lookup(serial); - if (IS_ERR(key)) { - ret = ERR_CAST(key); + if (kstrtos32(key_text, 0, &serial) < 0) goto out; + + if ((serial == 0) && allow_null_key) { + key = NULL; + } else { + key = key_lookup(serial); + if (IS_ERR(key)) { + ret = ERR_CAST(key); + goto out; + } } - ret = asymmetric_restriction_alloc( - restrict_link_by_key_or_keyring, key); + ret = asymmetric_restriction_alloc(link_fn, key); if (IS_ERR(ret)) key_put(key); } diff --git a/crypto/asymmetric_keys/restrict.c b/crypto/asymmetric_keys/restrict.c index 183cb642580e..86fb68508952 100644 --- a/crypto/asymmetric_keys/restrict.c +++ b/crypto/asymmetric_keys/restrict.c @@ -109,31 +109,20 @@ int restrict_link_by_signature(struct key *dest_keyring, return ret; } -/** - * restrict_link_by_key_or_keyring - Restrict additions to a ring of public - * keys using the restrict_key information stored in the ring. - * @dest_keyring: Keyring being linked to. - * @type: The type of key being added. - * @payload: The payload of the new key. - * @trusted: A key or ring of keys that can be used to vouch for the new cert. - * - * Check the new certificate only against the key or keys passed in the data - * parameter. If one of those is the signing key and validates the new - * certificate, then mark the new certificate as being ok to link. - * - * Returns 0 if the new certificate was accepted, -ENOKEY if we - * couldn't find a matching parent certificate in the trusted list, - * -EKEYREJECTED if the signature check fails, and some other error if - * there is a matching certificate but the signature check cannot be - * performed. - */ -int restrict_link_by_key_or_keyring(struct key *dest_keyring, - const struct key_type *type, - const union key_payload *payload, - struct key *trusted) +static bool match_either_id(const struct asymmetric_key_ids *pair, + const struct asymmetric_key_id *single) +{ + return (asymmetric_key_id_same(pair->id[0], single) || + asymmetric_key_id_same(pair->id[1], single)); +} + +static int key_or_keyring_common(struct key *dest_keyring, + const struct key_type *type, + const union key_payload *payload, + struct key *trusted, bool check_dest) { const struct public_key_signature *sig; - struct key *key; + struct key *key = NULL; int ret; pr_devel("==>%s()\n", __func__); @@ -143,7 +132,7 @@ int restrict_link_by_key_or_keyring(struct key *dest_keyring, else if (dest_keyring->type != &key_type_keyring) return -EOPNOTSUPP; - if (!trusted) + if (!trusted && !check_dest) return -ENOKEY; if (type != &key_type_asymmetric) @@ -153,25 +142,64 @@ int restrict_link_by_key_or_keyring(struct key *dest_keyring, if (!sig->auth_ids[0] && !sig->auth_ids[1]) return -ENOKEY; - if (trusted->type == &key_type_keyring) { - /* See if we have a key that signed this one. */ - key = find_asymmetric_key(trusted, sig->auth_ids[0], - sig->auth_ids[1], false); - if (IS_ERR(key)) - return -ENOKEY; - } else if (trusted->type == &key_type_asymmetric) { - const struct asymmetric_key_ids *kids; + if (trusted) { + if (trusted->type == &key_type_keyring) { + /* See if we have a key that signed this one. */ + key = find_asymmetric_key(trusted, sig->auth_ids[0], + sig->auth_ids[1], false); + if (IS_ERR(key)) + key = NULL; + } else if (trusted->type == &key_type_asymmetric) { + const struct asymmetric_key_ids *signer_ids; - kids = asymmetric_key_ids(trusted); + signer_ids = asymmetric_key_ids(trusted); - if (!asymmetric_key_id_same(kids->id[1], sig->auth_ids[0])) - return -ENOKEY; + /* + * The auth_ids come from the candidate key (the + * one that is being considered for addition to + * dest_keyring) and identify the key that was + * used to sign. + * + * The signer_ids are identifiers for the + * signing key specified for dest_keyring. + * + * The first auth_id is the preferred id, and + * the second is the fallback. If only one + * auth_id is present, it may match against + * either signer_id. If two auth_ids are + * present, the first auth_id must match one + * signer_id and the second auth_id must match + * the second signer_id. + */ + if (!sig->auth_ids[0] || !sig->auth_ids[1]) { + const struct asymmetric_key_id *auth_id; - key = __key_get(trusted); - } else { - return -EOPNOTSUPP; + auth_id = sig->auth_ids[0] ?: sig->auth_ids[1]; + if (match_either_id(signer_ids, auth_id)) + key = __key_get(trusted); + + } else if (asymmetric_key_id_same(signer_ids->id[1], + sig->auth_ids[1]) && + match_either_id(signer_ids, + sig->auth_ids[0])) { + key = __key_get(trusted); + } + } else { + return -EOPNOTSUPP; + } } + if (check_dest && !key) { + /* See if the destination has a key that signed this one. */ + key = find_asymmetric_key(dest_keyring, sig->auth_ids[0], + sig->auth_ids[1], false); + if (IS_ERR(key)) + key = NULL; + } + + if (!key) + return -ENOKEY; + ret = key_validate(key); if (ret == 0) ret = verify_signature(key, sig); @@ -179,3 +207,57 @@ int restrict_link_by_key_or_keyring(struct key *dest_keyring, key_put(key); return ret; } + +/** + * restrict_link_by_key_or_keyring - Restrict additions to a ring of public + * keys using the restrict_key information stored in the ring. + * @dest_keyring: Keyring being linked to. + * @type: The type of key being added. + * @payload: The payload of the new key. + * @trusted: A key or ring of keys that can be used to vouch for the new cert. + * + * Check the new certificate only against the key or keys passed in the data + * parameter. If one of those is the signing key and validates the new + * certificate, then mark the new certificate as being ok to link. + * + * Returns 0 if the new certificate was accepted, -ENOKEY if we + * couldn't find a matching parent certificate in the trusted list, + * -EKEYREJECTED if the signature check fails, and some other error if + * there is a matching certificate but the signature check cannot be + * performed. + */ +int restrict_link_by_key_or_keyring(struct key *dest_keyring, + const struct key_type *type, + const union key_payload *payload, + struct key *trusted) +{ + return key_or_keyring_common(dest_keyring, type, payload, trusted, + false); +} + +/** + * restrict_link_by_key_or_keyring_chain - Restrict additions to a ring of + * public keys using the restrict_key information stored in the ring. + * @dest_keyring: Keyring being linked to. + * @type: The type of key being added. + * @payload: The payload of the new key. + * @trusted: A key or ring of keys that can be used to vouch for the new cert. + * + * Check the new certificate only against the key or keys passed in the data + * parameter. If one of those is the signing key and validates the new + * certificate, then mark the new certificate as being ok to link. + * + * Returns 0 if the new certificate was accepted, -ENOKEY if we + * couldn't find a matching parent certificate in the trusted list, + * -EKEYREJECTED if the signature check fails, and some other error if + * there is a matching certificate but the signature check cannot be + * performed. + */ +int restrict_link_by_key_or_keyring_chain(struct key *dest_keyring, + const struct key_type *type, + const union key_payload *payload, + struct key *trusted) +{ + return key_or_keyring_common(dest_keyring, type, payload, trusted, + true); +} |