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authorDavid Howells <dhowells@redhat.com>2014-07-22 21:54:43 +0100
committerDavid Howells <dhowells@redhat.com>2014-07-22 21:54:43 +0100
commit64724cfc6eea920dbaada14f0fb978b1dd31192d (patch)
treed2f491be07a05e2d96b5c8b8e5a0a878f285eb22
parent6204e0025566ad3992ce649d4f44b7e8cdde2293 (diff)
parent7d2ce2320e8efdc4a6dcbae7b329ed3f0d1cd778 (diff)
Merge remote-tracking branch 'integrity/next-with-keys' into keys-next
Signed-off-by: David Howells <dhowells@redhat.com>
-rw-r--r--Documentation/kernel-parameters.txt5
-rw-r--r--crypto/asymmetric_keys/asymmetric_keys.h2
-rw-r--r--crypto/asymmetric_keys/asymmetric_type.c51
-rw-r--r--crypto/asymmetric_keys/x509_public_key.c109
-rw-r--r--include/keys/system_keyring.h10
-rw-r--r--include/linux/key.h1
-rw-r--r--kernel/system_keyring.c1
-rw-r--r--security/integrity/digsig.c28
-rw-r--r--security/integrity/ima/Kconfig10
-rw-r--r--security/integrity/ima/ima.h12
-rw-r--r--security/integrity/ima/ima_main.c10
-rw-r--r--security/integrity/integrity.h5
-rw-r--r--security/keys/keyctl.c6
13 files changed, 225 insertions, 25 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 8b2ab548b6e4..90c12c591168 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -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.
diff --git a/crypto/asymmetric_keys/asymmetric_keys.h b/crypto/asymmetric_keys/asymmetric_keys.h
index 515b63430812..a63c551c6557 100644
--- a/crypto/asymmetric_keys/asymmetric_keys.h
+++ b/crypto/asymmetric_keys/asymmetric_keys.h
@@ -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];
diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c
index 21960a4e74e8..eb8cd46961a5 100644
--- a/crypto/asymmetric_keys/asymmetric_type.c
+++ b/crypto/asymmetric_keys/asymmetric_type.c
@@ -23,6 +23,35 @@ 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)
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 3fc8a0634ed7..a0f7cd196c9b 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -18,11 +18,80 @@
#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.
@@ -103,6 +172,40 @@ 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.
*/
static int x509_key_preparse(struct key_preparsed_payload *prep)
@@ -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 */
diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h
index 8dabc399bd1d..72665eb80692 100644
--- a/include/keys/system_keyring.h
+++ b/include/keys/system_keyring.h
@@ -17,7 +17,15 @@
#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 */
diff --git a/include/linux/key.h b/include/linux/key.h
index 017b0826642f..65316f7ae794 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -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
diff --git a/kernel/system_keyring.c b/kernel/system_keyring.c
index 52ebc70263f4..875f64e8935b 100644
--- a/kernel/system_keyring.c
+++ b/kernel/system_keyring.c
@@ -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);
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index b4af4ebc5be2..8d4fbff8b87c 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -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;
+}
diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig
index 81a27971d884..08758fbd496f 100644
--- a/security/integrity/ima/Kconfig
+++ b/security/integrity/ima/Kconfig
@@ -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.
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index f79fa8be203c..c42056edfc97 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -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
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index f474c608fa11..0d696431209c 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -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;
}
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 33c0a70f6b15..09c440d9aaee 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -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
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index cd5bd0cef25d..8a8c23357291 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -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;
}
}

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