]> git.karo-electronics.de Git - linux-beck.git/commitdiff
Merge remote-tracking branch 'integrity/next-with-keys' into keys-next
authorDavid Howells <dhowells@redhat.com>
Tue, 22 Jul 2014 20:54:43 +0000 (21:54 +0100)
committerDavid Howells <dhowells@redhat.com>
Tue, 22 Jul 2014 20:54:43 +0000 (21:54 +0100)
Signed-off-by: David Howells <dhowells@redhat.com>
13 files changed:
Documentation/kernel-parameters.txt
crypto/asymmetric_keys/asymmetric_keys.h
crypto/asymmetric_keys/asymmetric_type.c
crypto/asymmetric_keys/x509_public_key.c
include/keys/system_keyring.h
include/linux/key.h
kernel/system_keyring.c
security/integrity/digsig.c
security/integrity/ima/Kconfig
security/integrity/ima/ima.h
security/integrity/ima/ima_main.c
security/integrity/integrity.h
security/keys/keyctl.c

index 8b2ab548b6e42ef9657a5bc7f004d04abfe5ad10..90c12c59116830cd67e7fecda515f0ee33a8a103 100644 (file)
@@ -566,6 +566,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        possible to determine what the correct size should be.
                        This option provides an override for these situations.
 
+       ca_keys=        [KEYS] This parameter identifies a specific key(s) on
+                       the system trusted keyring to be used for certificate
+                       trust validation.
+                       format: { id:<keyid> | builtin }
+
        ccw_timeout_log [S390]
                        See Documentation/s390/CommonIO for details.
 
index 515b634308121972f4a79bdcff917a49a6ba4ff8..a63c551c65570006ef2281ad2dc3ad6b70622482 100644 (file)
@@ -9,6 +9,8 @@
  * 2 of the Licence, or (at your option) any later version.
  */
 
+int asymmetric_keyid_match(const char *kid, const char *id);
+
 static inline const char *asymmetric_key_id(const struct key *key)
 {
        return key->type_data.p[1];
index 21960a4e74e8c193e8a69e07e0611c7139aaa82f..eb8cd46961a5aa5a6a7470c6d17008d1745bbdf6 100644 (file)
@@ -22,6 +22,35 @@ MODULE_LICENSE("GPL");
 static LIST_HEAD(asymmetric_key_parsers);
 static DECLARE_RWSEM(asymmetric_key_parsers_sem);
 
+/*
+ * Match asymmetric key id with partial match
+ * @id:                key id to match in a form "id:<id>"
+ */
+int asymmetric_keyid_match(const char *kid, const char *id)
+{
+       size_t idlen, kidlen;
+
+       if (!kid || !id)
+               return 0;
+
+       /* make it possible to use id as in the request: "id:<id>" */
+       if (strncmp(id, "id:", 3) == 0)
+               id += 3;
+
+       /* Anything after here requires a partial match on the ID string */
+       idlen = strlen(id);
+       kidlen = strlen(kid);
+       if (idlen > kidlen)
+               return 0;
+
+       kid += kidlen - idlen;
+       if (strcasecmp(id, kid) != 0)
+               return 0;
+
+       return 1;
+}
+EXPORT_SYMBOL_GPL(asymmetric_keyid_match);
+
 /*
  * Match asymmetric keys on (part of) their name
  * We have some shorthand methods for matching keys.  We allow:
@@ -34,9 +63,8 @@ static int asymmetric_key_match(const struct key *key, const void *description)
 {
        const struct asymmetric_key_subtype *subtype = asymmetric_key_subtype(key);
        const char *spec = description;
-       const char *id, *kid;
+       const char *id;
        ptrdiff_t speclen;
-       size_t idlen, kidlen;
 
        if (!subtype || !spec || !*spec)
                return 0;
@@ -55,23 +83,8 @@ static int asymmetric_key_match(const struct key *key, const void *description)
        speclen = id - spec;
        id++;
 
-       /* Anything after here requires a partial match on the ID string */
-       kid = asymmetric_key_id(key);
-       if (!kid)
-               return 0;
-
-       idlen = strlen(id);
-       kidlen = strlen(kid);
-       if (idlen > kidlen)
-               return 0;
-
-       kid += kidlen - idlen;
-       if (strcasecmp(id, kid) != 0)
-               return 0;
-
-       if (speclen == 2 &&
-           memcmp(spec, "id", 2) == 0)
-               return 1;
+       if (speclen == 2 && memcmp(spec, "id", 2) == 0)
+               return asymmetric_keyid_match(asymmetric_key_id(key), id);
 
        if (speclen == subtype->name_len &&
            memcmp(spec, subtype->name, speclen) == 0)
index 3fc8a0634ed7daa5eabd40a25f79e02374e67fbb..a0f7cd196c9b031f1448f1c3b9c2795a56301b48 100644 (file)
 #include <linux/asn1_decoder.h>
 #include <keys/asymmetric-subtype.h>
 #include <keys/asymmetric-parser.h>
+#include <keys/system_keyring.h>
 #include <crypto/hash.h>
 #include "asymmetric_keys.h"
 #include "public_key.h"
 #include "x509_parser.h"
 
+static bool use_builtin_keys;
+static char *ca_keyid;
+
+#ifndef MODULE
+static int __init ca_keys_setup(char *str)
+{
+       if (!str)               /* default system keyring */
+               return 1;
+
+       if (strncmp(str, "id:", 3) == 0)
+               ca_keyid = str; /* owner key 'id:xxxxxx' */
+       else if (strcmp(str, "builtin") == 0)
+               use_builtin_keys = true;
+
+       return 1;
+}
+__setup("ca_keys=", ca_keys_setup);
+#endif
+
+/*
+ * Find a key in the given keyring by issuer and authority.
+ */
+static struct key *x509_request_asymmetric_key(struct key *keyring,
+                                              const char *signer,
+                                              size_t signer_len,
+                                              const char *authority,
+                                              size_t auth_len)
+{
+       key_ref_t key;
+       char *id;
+
+       /* Construct an identifier. */
+       id = kmalloc(signer_len + 2 + auth_len + 1, GFP_KERNEL);
+       if (!id)
+               return ERR_PTR(-ENOMEM);
+
+       memcpy(id, signer, signer_len);
+       id[signer_len + 0] = ':';
+       id[signer_len + 1] = ' ';
+       memcpy(id + signer_len + 2, authority, auth_len);
+       id[signer_len + 2 + auth_len] = 0;
+
+       pr_debug("Look up: \"%s\"\n", id);
+
+       key = keyring_search(make_key_ref(keyring, 1),
+                            &key_type_asymmetric, id);
+       if (IS_ERR(key))
+               pr_debug("Request for module key '%s' err %ld\n",
+                        id, PTR_ERR(key));
+       kfree(id);
+
+       if (IS_ERR(key)) {
+               switch (PTR_ERR(key)) {
+                       /* Hide some search errors */
+               case -EACCES:
+               case -ENOTDIR:
+               case -EAGAIN:
+                       return ERR_PTR(-ENOKEY);
+               default:
+                       return ERR_CAST(key);
+               }
+       }
+
+       pr_devel("<==%s() = 0 [%x]\n", __func__,
+                key_serial(key_ref_to_ptr(key)));
+       return key_ref_to_ptr(key);
+}
+
 /*
  * Set up the signature parameters in an X.509 certificate.  This involves
  * digesting the signed data and extracting the signature.
@@ -102,6 +171,40 @@ int x509_check_signature(const struct public_key *pub,
 }
 EXPORT_SYMBOL_GPL(x509_check_signature);
 
+/*
+ * Check the new certificate against the ones in the trust keyring.  If one of
+ * those is the signing key and validates the new certificate, then mark the
+ * new certificate as being trusted.
+ *
+ * Return 0 if the new certificate was successfully validated, 1 if we couldn't
+ * find a matching parent certificate in the trusted list and an error if there
+ * is a matching certificate but the signature check fails.
+ */
+static int x509_validate_trust(struct x509_certificate *cert,
+                              struct key *trust_keyring)
+{
+       struct key *key;
+       int ret = 1;
+
+       if (!trust_keyring)
+               return -EOPNOTSUPP;
+
+       if (ca_keyid && !asymmetric_keyid_match(cert->authority, ca_keyid))
+               return -EPERM;
+
+       key = x509_request_asymmetric_key(trust_keyring,
+                                         cert->issuer, strlen(cert->issuer),
+                                         cert->authority,
+                                         strlen(cert->authority));
+       if (!IS_ERR(key))  {
+               if (!use_builtin_keys
+                   || test_bit(KEY_FLAG_BUILTIN, &key->flags))
+                       ret = x509_check_signature(key->payload.data, cert);
+               key_put(key);
+       }
+       return ret;
+}
+
 /*
  * Attempt to parse a data blob for a key as an X509 certificate.
  */
@@ -155,9 +258,13 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
        /* Check the signature on the key if it appears to be self-signed */
        if (!cert->authority ||
            strcmp(cert->fingerprint, cert->authority) == 0) {
-               ret = x509_check_signature(cert->pub, cert);
+               ret = x509_check_signature(cert->pub, cert); /* self-signed */
                if (ret < 0)
                        goto error_free_cert;
+       } else if (!prep->trusted) {
+               ret = x509_validate_trust(cert, get_system_trusted_keyring());
+               if (!ret)
+                       prep->trusted = 1;
        }
 
        /* Propose a description */
index 8dabc399bd1d156d9ced4d371ba8b8136deea5f4..72665eb8069269f4e1b6726c8cd2d04374405ab8 100644 (file)
 #include <linux/key.h>
 
 extern struct key *system_trusted_keyring;
-
+static inline struct key *get_system_trusted_keyring(void)
+{
+       return system_trusted_keyring;
+}
+#else
+static inline struct key *get_system_trusted_keyring(void)
+{
+       return NULL;
+}
 #endif
 
 #endif /* _KEYS_SYSTEM_KEYRING_H */
index 017b0826642f04c070137114ee98958737677cd6..65316f7ae79437a8bfedcb0ed2a3338dafab3b7e 100644 (file)
@@ -170,6 +170,7 @@ struct key {
 #define KEY_FLAG_INVALIDATED   7       /* set if key has been invalidated */
 #define KEY_FLAG_TRUSTED       8       /* set if key is trusted */
 #define KEY_FLAG_TRUSTED_ONLY  9       /* set if keyring only accepts links to trusted keys */
+#define KEY_FLAG_BUILTIN       10      /* set if key is builtin */
 
        /* the key type and key description string
         * - the desc is used to match a key against search criteria
index 52ebc70263f4d8e806dc436fd55e6000cf818915..875f64e8935bbf1f27320a42ae467f170b09e3d9 100644 (file)
@@ -89,6 +89,7 @@ static __init int load_system_certificate_list(void)
                        pr_err("Problem loading in-kernel X.509 certificate (%ld)\n",
                               PTR_ERR(key));
                } else {
+                       set_bit(KEY_FLAG_BUILTIN, &key_ref_to_ptr(key)->flags);
                        pr_notice("Loaded X.509 cert '%s'\n",
                                  key_ref_to_ptr(key)->description);
                        key_ref_put(key);
index b4af4ebc5be284d7f2665a5266be6a5bf267a683..8d4fbff8b87ca80460c9192610c01add6a150aa0 100644 (file)
@@ -13,7 +13,9 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/err.h>
+#include <linux/sched.h>
 #include <linux/rbtree.h>
+#include <linux/cred.h>
 #include <linux/key-type.h>
 #include <linux/digsig.h>
 
@@ -24,7 +26,11 @@ static struct key *keyring[INTEGRITY_KEYRING_MAX];
 static const char *keyring_name[INTEGRITY_KEYRING_MAX] = {
        "_evm",
        "_module",
+#ifndef CONFIG_IMA_TRUSTED_KEYRING
        "_ima",
+#else
+       ".ima",
+#endif
 };
 
 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
@@ -56,3 +62,25 @@ int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
 
        return -EOPNOTSUPP;
 }
+
+int integrity_init_keyring(const unsigned int id)
+{
+       const struct cred *cred = current_cred();
+       int err = 0;
+
+       keyring[id] = keyring_alloc(keyring_name[id], KUIDT_INIT(0),
+                                   KGIDT_INIT(0), cred,
+                                   ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
+                                    KEY_USR_VIEW | KEY_USR_READ |
+                                    KEY_USR_WRITE | KEY_USR_SEARCH),
+                                   KEY_ALLOC_NOT_IN_QUOTA, NULL);
+       if (!IS_ERR(keyring[id]))
+               set_bit(KEY_FLAG_TRUSTED_ONLY, &keyring[id]->flags);
+       else {
+               err = PTR_ERR(keyring[id]);
+               pr_info("Can't allocate %s keyring (%d)\n",
+                       keyring_name[id], err);
+               keyring[id] = NULL;
+       }
+       return err;
+}
index 81a27971d884215bc20e71d756f6778893ae1d67..08758fbd496f90c9176a726d3f48b7d91bb3e82a 100644 (file)
@@ -123,3 +123,13 @@ config IMA_APPRAISE
          For more information on integrity appraisal refer to:
          <http://linux-ima.sourceforge.net>
          If unsure, say N.
+
+config IMA_TRUSTED_KEYRING
+       bool "Require all keys on the .ima keyring be signed"
+       depends on IMA_APPRAISE && SYSTEM_TRUSTED_KEYRING
+       depends on INTEGRITY_ASYMMETRIC_KEYS
+       select KEYS_DEBUG_PROC_KEYS
+       default y
+       help
+          This option requires that all keys added to the .ima
+          keyring be signed by a key on the system trusted keyring.
index f79fa8be203cd3703ad1a7fedddfe7037f602cdd..c42056edfc97699a7e85d7c1826614ef3686981f 100644 (file)
@@ -249,4 +249,16 @@ static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
        return -EINVAL;
 }
 #endif /* CONFIG_IMA_LSM_RULES */
+
+#ifdef CONFIG_IMA_TRUSTED_KEYRING
+static inline int ima_init_keyring(const unsigned int id)
+{
+       return integrity_init_keyring(id);
+}
+#else
+static inline int ima_init_keyring(const unsigned int id)
+{
+       return 0;
+}
+#endif /* CONFIG_IMA_TRUSTED_KEYRING */
 #endif
index f474c608fa1194ebde04e21f2bdabc5be64c5d4a..0d696431209c09e1ac3f1c55145544648dbfa3be 100644 (file)
@@ -325,8 +325,14 @@ static int __init init_ima(void)
 
        hash_setup(CONFIG_IMA_DEFAULT_HASH);
        error = ima_init();
-       if (!error)
-               ima_initialized = 1;
+       if (error)
+               goto out;
+
+       error = ima_init_keyring(INTEGRITY_KEYRING_IMA);
+       if (error)
+               goto out;
+       ima_initialized = 1;
+out:
        return error;
 }
 
index 33c0a70f6b15a66a7b024aa8fbb534d72c76c898..09c440d9aaee5b3c1624a93c7cebd45f3cf0d1c6 100644 (file)
@@ -124,6 +124,7 @@ struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
                            const char *digest, int digestlen);
 
+int integrity_init_keyring(const unsigned int id);
 #else
 
 static inline int integrity_digsig_verify(const unsigned int id,
@@ -133,6 +134,10 @@ static inline int integrity_digsig_verify(const unsigned int id,
        return -EOPNOTSUPP;
 }
 
+static inline int integrity_init_keyring(const unsigned int id)
+{
+       return 0;
+}
 #endif /* CONFIG_INTEGRITY_SIGNATURE */
 
 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
index cd5bd0cef25df3fce5801e938567e156d47f275f..8a8c23357291471a35a201ebfcde9f08c2e9b893 100644 (file)
@@ -37,8 +37,6 @@ static int key_get_type_from_user(char *type,
                return ret;
        if (ret == 0 || ret >= len)
                return -EINVAL;
-       if (type[0] == '.')
-               return -EPERM;
        type[len - 1] = '\0';
        return 0;
 }
@@ -86,6 +84,10 @@ SYSCALL_DEFINE5(add_key, const char __user *, _type,
                if (!*description) {
                        kfree(description);
                        description = NULL;
+               } else if ((description[0] == '.') &&
+                          (strncmp(type, "keyring", 7) == 0)) {
+                       ret = -EPERM;
+                       goto error2;
                }
        }