Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
[cascardo/linux.git] / certs / system_keyring.c
index a83bffe..50979d6 100644 (file)
 #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));
@@ -113,7 +172,8 @@ late_initcall(load_system_certificate_list);
  * @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 system_trusted_keyring).
+ * @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.
@@ -121,7 +181,6 @@ late_initcall(load_system_certificate_list);
 int verify_pkcs7_signature(const void *data, size_t len,
                           const void *raw_pkcs7, size_t pkcs7_len,
                           struct key *trusted_keys,
-                          int untrusted_error,
                           enum key_being_used_for usage,
                           int (*view_content)(void *ctx,
                                               const void *data, size_t len,
@@ -129,7 +188,6 @@ int verify_pkcs7_signature(const void *data, size_t len,
                           void *ctx)
 {
        struct pkcs7_message *pkcs7;
-       bool trusted;
        int ret;
 
        pkcs7 = pkcs7_parse_message(raw_pkcs7, pkcs7_len);
@@ -147,15 +205,19 @@ int verify_pkcs7_signature(const void *data, size_t len,
        if (ret < 0)
                goto error;
 
-       if (!trusted_keys)
-               trusted_keys = system_trusted_keyring;
-       ret = pkcs7_validate_trust(pkcs7, trusted_keys, &trusted);
-       if (ret < 0)
-               goto error;
-
-       if (!trusted && untrusted_error) {
-               pr_err("PKCS#7 signature not signed with a trusted key\n");
-               ret = untrusted_error;
+       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;
        }