diff options
Diffstat (limited to 'certs/system_keyring.c')
| -rw-r--r-- | certs/system_keyring.c | 139 |
1 files changed, 113 insertions, 26 deletions
diff --git a/certs/system_keyring.c b/certs/system_keyring.c index f4180326c2e1..50979d6dcecd 100644 --- a/certs/system_keyring.c +++ b/certs/system_keyring.c @@ -18,29 +18,88 @@ #include <keys/system_keyring.h> #include <crypto/pkcs7.h> -struct key *system_trusted_keyring; -EXPORT_SYMBOL_GPL(system_trusted_keyring); +static struct key *builtin_trusted_keys; +#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING +static struct key *secondary_trusted_keys; +#endif extern __initconst const u8 system_certificate_list[]; extern __initconst const unsigned long system_certificate_list_size; +/** + * restrict_link_to_builtin_trusted - Restrict keyring addition by built in CA + * + * 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. + */ +int restrict_link_by_builtin_trusted(struct key *keyring, + const struct key_type *type, + const union key_payload *payload) +{ + return restrict_link_by_signature(builtin_trusted_keys, type, payload); +} + +#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING +/** + * restrict_link_by_builtin_and_secondary_trusted - Restrict keyring + * addition by both builtin and secondary keyrings + * + * 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. + */ +int restrict_link_by_builtin_and_secondary_trusted( + struct key *keyring, + const struct key_type *type, + const union key_payload *payload) +{ + /* 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 && + 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_signature(secondary_trusted_keys, type, payload); +} +#endif + /* - * Load the compiled-in keys + * Create the trusted keyrings */ static __init int system_trusted_keyring_init(void) { - pr_notice("Initialise system trusted keyring\n"); + pr_notice("Initialise system trusted keyrings\n"); - system_trusted_keyring = - keyring_alloc(".system_keyring", + builtin_trusted_keys = + keyring_alloc(".builtin_trusted_keys", KUIDT_INIT(0), KGIDT_INIT(0), current_cred(), ((KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH), - KEY_ALLOC_NOT_IN_QUOTA, NULL); - if (IS_ERR(system_trusted_keyring)) - panic("Can't allocate system trusted keyring\n"); + KEY_ALLOC_NOT_IN_QUOTA, + NULL, NULL); + if (IS_ERR(builtin_trusted_keys)) + panic("Can't allocate builtin trusted keyring\n"); + +#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING + secondary_trusted_keys = + keyring_alloc(".secondary_trusted_keys", + KUIDT_INIT(0), KGIDT_INIT(0), current_cred(), + ((KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH | + KEY_USR_WRITE), + KEY_ALLOC_NOT_IN_QUOTA, + restrict_link_by_builtin_and_secondary_trusted, + NULL); + if (IS_ERR(secondary_trusted_keys)) + panic("Can't allocate secondary trusted keyring\n"); + + if (key_link(secondary_trusted_keys, builtin_trusted_keys) < 0) + panic("Can't link trusted keyrings\n"); +#endif - set_bit(KEY_FLAG_TRUSTED_ONLY, &system_trusted_keyring->flags); return 0; } @@ -76,7 +135,7 @@ static __init int load_system_certificate_list(void) if (plen > end - p) goto dodgy_cert; - key = key_create_or_update(make_key_ref(system_trusted_keyring, 1), + key = key_create_or_update(make_key_ref(builtin_trusted_keys, 1), "asymmetric", NULL, p, @@ -84,8 +143,8 @@ static __init int load_system_certificate_list(void) ((KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ), KEY_ALLOC_NOT_IN_QUOTA | - KEY_ALLOC_TRUSTED | - KEY_ALLOC_BUILT_IN); + KEY_ALLOC_BUILT_IN | + KEY_ALLOC_BYPASS_RESTRICTION); if (IS_ERR(key)) { pr_err("Problem loading in-kernel X.509 certificate (%ld)\n", PTR_ERR(key)); @@ -108,19 +167,27 @@ late_initcall(load_system_certificate_list); #ifdef CONFIG_SYSTEM_DATA_VERIFICATION /** - * Verify a PKCS#7-based signature on system data. - * @data: The data to be verified. + * verify_pkcs7_signature - Verify a PKCS#7-based signature on system data. + * @data: The data to be verified (NULL if expecting internal data). * @len: Size of @data. * @raw_pkcs7: The PKCS#7 message that is the signature. * @pkcs7_len: The size of @raw_pkcs7. + * @trusted_keys: Trusted keys to use (NULL for builtin trusted keys only, + * (void *)1UL for all trusted keys). * @usage: The use to which the key is being put. + * @view_content: Callback to gain access to content. + * @ctx: Context for callback. */ -int system_verify_data(const void *data, unsigned long len, - const void *raw_pkcs7, size_t pkcs7_len, - enum key_being_used_for usage) +int verify_pkcs7_signature(const void *data, size_t len, + const void *raw_pkcs7, size_t pkcs7_len, + struct key *trusted_keys, + enum key_being_used_for usage, + int (*view_content)(void *ctx, + const void *data, size_t len, + size_t asn1hdrlen), + void *ctx) { struct pkcs7_message *pkcs7; - bool trusted; int ret; pkcs7 = pkcs7_parse_message(raw_pkcs7, pkcs7_len); @@ -128,7 +195,7 @@ int system_verify_data(const void *data, unsigned long len, return PTR_ERR(pkcs7); /* The data should be detached - so we need to supply it. */ - if (pkcs7_supply_detached_data(pkcs7, data, len) < 0) { + if (data && pkcs7_supply_detached_data(pkcs7, data, len) < 0) { pr_err("PKCS#7 signature with non-detached data\n"); ret = -EBADMSG; goto error; @@ -138,13 +205,33 @@ int system_verify_data(const void *data, unsigned long len, if (ret < 0) goto error; - ret = pkcs7_validate_trust(pkcs7, system_trusted_keyring, &trusted); - if (ret < 0) + if (!trusted_keys) { + trusted_keys = builtin_trusted_keys; + } else if (trusted_keys == (void *)1UL) { +#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING + trusted_keys = secondary_trusted_keys; +#else + trusted_keys = builtin_trusted_keys; +#endif + } + ret = pkcs7_validate_trust(pkcs7, trusted_keys); + if (ret < 0) { + if (ret == -ENOKEY) + pr_err("PKCS#7 signature not signed with a trusted key\n"); goto error; + } + + if (view_content) { + size_t asn1hdrlen; + + ret = pkcs7_get_content_data(pkcs7, &data, &len, &asn1hdrlen); + if (ret < 0) { + if (ret == -ENODATA) + pr_devel("PKCS#7 message does not contain data\n"); + goto error; + } - if (!trusted) { - pr_err("PKCS#7 signature not signed with a trusted key\n"); - ret = -ENOKEY; + ret = view_content(ctx, data, len, asn1hdrlen); } error: @@ -152,6 +239,6 @@ error: pr_devel("<==%s() = %d\n", __func__, ret); return ret; } -EXPORT_SYMBOL_GPL(system_verify_data); +EXPORT_SYMBOL_GPL(verify_pkcs7_signature); #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ |