[RFC PATCH 05/12] KEYS: Generalise x509_request_asymmetric_key() [ver #3]

From: David Howells
Date: Wed Mar 09 2016 - 06:22:08 EST


Generalise x509_request_asymmetric_key(). It doesn't really have any
dependencies on X.509 features as it uses generalised IDs and the
public_key structs that contain data extracted from X.509.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

crypto/asymmetric_keys/asymmetric_keys.h | 2 +
crypto/asymmetric_keys/asymmetric_type.c | 42 +++++++++++++++---------------
crypto/asymmetric_keys/pkcs7_trust.c | 19 ++++++--------
crypto/asymmetric_keys/x509_public_key.c | 5 +---
include/keys/asymmetric-type.h | 8 +++---
5 files changed, 37 insertions(+), 39 deletions(-)

diff --git a/crypto/asymmetric_keys/asymmetric_keys.h b/crypto/asymmetric_keys/asymmetric_keys.h
index 1d450b580245..ca8e9ac34ce6 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.
*/

+#include <keys/asymmetric-type.h>
+
extern struct asymmetric_key_id *asymmetric_key_hex_to_key_id(const char *id);

extern int __asymmetric_key_hex_to_key_id(const char *id,
diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c
index c4d66cd82860..6600181d5d01 100644
--- a/crypto/asymmetric_keys/asymmetric_type.c
+++ b/crypto/asymmetric_keys/asymmetric_type.c
@@ -35,21 +35,20 @@ static LIST_HEAD(asymmetric_key_parsers);
static DECLARE_RWSEM(asymmetric_key_parsers_sem);

/**
- * x509_request_asymmetric_key - Request a key by X.509 certificate params.
+ * find_asymmetric_key - Find a key by ID.
* @keyring: The keys to search.
- * @id: The issuer & serialNumber to look for or NULL.
- * @skid: The subjectKeyIdentifier to look for or NULL.
+ * @id_0: The first ID to look for or NULL.
+ * @id_1: The second ID to look for or NULL.
* @partial: Use partial match if true, exact if false.
*
* Find a key in the given keyring by identifier. The preferred identifier is
- * the issuer + serialNumber and the fallback identifier is the
- * subjectKeyIdentifier. If both are given, the lookup is by the former, but
- * the latter must also match.
+ * the id_0 and the fallback identifier is the id_1. If both are given, the
+ * lookup is by the former, but the latter must also match.
*/
-struct key *x509_request_asymmetric_key(struct key *keyring,
- const struct asymmetric_key_id *id,
- const struct asymmetric_key_id *skid,
- bool partial)
+struct key *find_asymmetric_key(struct key *keyring,
+ const struct asymmetric_key_id *id_0,
+ const struct asymmetric_key_id *id_1,
+ bool partial)
{
struct key *key;
key_ref_t ref;
@@ -57,12 +56,12 @@ struct key *x509_request_asymmetric_key(struct key *keyring,
char *req, *p;
int len;

- if (id) {
- lookup = id->data;
- len = id->len;
+ if (id_0) {
+ lookup = id_0->data;
+ len = id_0->len;
} else {
- lookup = skid->data;
- len = skid->len;
+ lookup = id_1->data;
+ len = id_1->len;
}

/* Construct an identifier "id:<keyid>". */
@@ -102,14 +101,15 @@ struct key *x509_request_asymmetric_key(struct key *keyring,
}

key = key_ref_to_ptr(ref);
- if (id && skid) {
+ if (id_0 && id_1) {
const struct asymmetric_key_ids *kids = asymmetric_key_ids(key);
- if (!kids->id[1]) {
- pr_debug("issuer+serial match, but expected SKID missing\n");
+
+ if (!kids->id[0]) {
+ pr_debug("First ID matches, but second is missing\n");
goto reject;
}
- if (!asymmetric_key_id_same(skid, kids->id[1])) {
- pr_debug("issuer+serial match, but SKID does not\n");
+ if (!asymmetric_key_id_same(id_1, kids->id[1])) {
+ pr_debug("First ID matches, but second does not\n");
goto reject;
}
}
@@ -121,7 +121,7 @@ reject:
key_put(key);
return ERR_PTR(-EKEYREJECTED);
}
-EXPORT_SYMBOL_GPL(x509_request_asymmetric_key);
+EXPORT_SYMBOL_GPL(find_asymmetric_key);

/**
* asymmetric_key_generate_id: Construct an asymmetric key ID
diff --git a/crypto/asymmetric_keys/pkcs7_trust.c b/crypto/asymmetric_keys/pkcs7_trust.c
index 36e77cb07bd0..f6a009d88a33 100644
--- a/crypto/asymmetric_keys/pkcs7_trust.c
+++ b/crypto/asymmetric_keys/pkcs7_trust.c
@@ -51,9 +51,8 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
/* Look to see if this certificate is present in the trusted
* keys.
*/
- key = x509_request_asymmetric_key(trust_keyring,
- x509->id, x509->skid,
- false);
+ key = find_asymmetric_key(trust_keyring,
+ x509->id, x509->skid, false);
if (!IS_ERR(key)) {
/* One of the X.509 certificates in the PKCS#7 message
* is apparently the same as one we already trust.
@@ -84,10 +83,10 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
* trusted keys.
*/
if (last && (last->sig->auth_ids[0] || last->sig->auth_ids[1])) {
- key = x509_request_asymmetric_key(trust_keyring,
- last->sig->auth_ids[0],
- last->sig->auth_ids[1],
- false);
+ key = find_asymmetric_key(trust_keyring,
+ last->sig->auth_ids[0],
+ last->sig->auth_ids[1],
+ false);
if (!IS_ERR(key)) {
x509 = last;
pr_devel("sinfo %u: Root cert %u signer is key %x\n",
@@ -101,10 +100,8 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
/* As a last resort, see if we have a trusted public key that matches
* the signed info directly.
*/
- key = x509_request_asymmetric_key(trust_keyring,
- sinfo->sig->auth_ids[0],
- NULL,
- false);
+ key = find_asymmetric_key(trust_keyring,
+ sinfo->sig->auth_ids[0], NULL, false);
if (!IS_ERR(key)) {
pr_devel("sinfo %u: Direct signer is key %x\n",
sinfo->index, key_serial(key));
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 2fb594175cef..9c8483ef1cfe 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -213,9 +213,8 @@ static int x509_validate_trust(struct x509_certificate *cert,
if (cert->unsupported_sig)
return -ENOPKG;

- key = x509_request_asymmetric_key(trust_keyring,
- sig->auth_ids[0], sig->auth_ids[1],
- false);
+ key = find_asymmetric_key(trust_keyring,
+ sig->auth_ids[0], sig->auth_ids[1], false);
if (IS_ERR(key))
return PTR_ERR(key);

diff --git a/include/keys/asymmetric-type.h b/include/keys/asymmetric-type.h
index 735db697c4d2..b38240716d41 100644
--- a/include/keys/asymmetric-type.h
+++ b/include/keys/asymmetric-type.h
@@ -76,10 +76,10 @@ const struct asymmetric_key_ids *asymmetric_key_ids(const struct key *key)
return key->payload.data[asym_key_ids];
}

-extern struct key *x509_request_asymmetric_key(struct key *keyring,
- const struct asymmetric_key_id *id,
- const struct asymmetric_key_id *skid,
- bool partial);
+extern struct key *find_asymmetric_key(struct key *keyring,
+ const struct asymmetric_key_id *id_0,
+ const struct asymmetric_key_id *id_1,
+ bool partial);

/*
* The payload is at the discretion of the subtype.