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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 /crypto
parent6204e0025566ad3992ce649d4f44b7e8cdde2293 (diff)
parent7d2ce2320e8efdc4a6dcbae7b329ed3f0d1cd778 (diff)
downloadlinux-stericsson-64724cfc6eea920dbaada14f0fb978b1dd31192d.tar.gz
Merge remote-tracking branch 'integrity/next-with-keys' into keys-next
Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'crypto')
-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
3 files changed, 142 insertions, 20 deletions
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 */