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-rw-r--r--crypto/asymmetric_keys/pkcs7_trust.c10
-rw-r--r--crypto/asymmetric_keys/pkcs7_verify.c47
-rw-r--r--crypto/asymmetric_keys/x509_public_key.c84
-rw-r--r--include/crypto/public_key.h3
4 files changed, 103 insertions, 41 deletions
diff --git a/crypto/asymmetric_keys/pkcs7_trust.c b/crypto/asymmetric_keys/pkcs7_trust.c
index 0f6463b6692b..90d6d47965b0 100644
--- a/crypto/asymmetric_keys/pkcs7_trust.c
+++ b/crypto/asymmetric_keys/pkcs7_trust.c
@@ -54,7 +54,8 @@ 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,
+ key = x509_request_asymmetric_key(trust_keyring,
+ x509->id, x509->skid,
false);
if (!IS_ERR(key)) {
/* One of the X.509 certificates in the PKCS#7 message
@@ -85,8 +86,10 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
/* No match - see if the root certificate has a signer amongst the
* trusted keys.
*/
- if (last && last->akid_skid) {
- key = x509_request_asymmetric_key(trust_keyring, last->akid_skid,
+ if (last && (last->akid_id || last->akid_skid)) {
+ key = x509_request_asymmetric_key(trust_keyring,
+ last->akid_id,
+ last->akid_skid,
false);
if (!IS_ERR(key)) {
x509 = last;
@@ -103,6 +106,7 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
*/
key = x509_request_asymmetric_key(trust_keyring,
sinfo->signing_cert_id,
+ NULL,
false);
if (!IS_ERR(key)) {
pr_devel("sinfo %u: Direct signer is key %x\n",
diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c
index a4d083f7e9e1..42bfc9de0d79 100644
--- a/crypto/asymmetric_keys/pkcs7_verify.c
+++ b/crypto/asymmetric_keys/pkcs7_verify.c
@@ -170,6 +170,7 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
struct pkcs7_signed_info *sinfo)
{
struct x509_certificate *x509 = sinfo->signer, *p;
+ struct asymmetric_key_id *auth;
int ret;
kenter("");
@@ -187,11 +188,14 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
goto maybe_missing_crypto_in_x509;
pr_debug("- issuer %s\n", x509->issuer);
+ if (x509->akid_id)
+ pr_debug("- authkeyid.id %*phN\n",
+ x509->akid_id->len, x509->akid_id->data);
if (x509->akid_skid)
- pr_debug("- authkeyid %*phN\n",
+ pr_debug("- authkeyid.skid %*phN\n",
x509->akid_skid->len, x509->akid_skid->data);
- if (!x509->akid_skid ||
+ if ((!x509->akid_id && !x509->akid_skid) ||
strcmp(x509->subject, x509->issuer) == 0) {
/* If there's no authority certificate specified, then
* the certificate must be self-signed and is the root
@@ -215,21 +219,42 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
/* Look through the X.509 certificates in the PKCS#7 message's
* list to see if the next one is there.
*/
- pr_debug("- want %*phN\n",
- x509->akid_skid->len, x509->akid_skid->data);
- for (p = pkcs7->certs; p; p = p->next) {
- if (!p->skid)
- continue;
- pr_debug("- cmp [%u] %*phN\n",
- p->index, p->skid->len, p->skid->data);
- if (asymmetric_key_id_same(p->skid, x509->akid_skid))
- goto found_issuer;
+ auth = x509->akid_id;
+ if (auth) {
+ pr_debug("- want %*phN\n", auth->len, auth->data);
+ for (p = pkcs7->certs; p; p = p->next) {
+ pr_debug("- cmp [%u] %*phN\n",
+ p->index, p->id->len, p->id->data);
+ if (asymmetric_key_id_same(p->id, auth))
+ goto found_issuer_check_skid;
+ }
+ } else {
+ auth = x509->akid_skid;
+ pr_debug("- want %*phN\n", auth->len, auth->data);
+ for (p = pkcs7->certs; p; p = p->next) {
+ if (!p->skid)
+ continue;
+ pr_debug("- cmp [%u] %*phN\n",
+ p->index, p->skid->len, p->skid->data);
+ if (asymmetric_key_id_same(p->skid, auth))
+ goto found_issuer;
+ }
}
/* We didn't find the root of this chain */
pr_debug("- top\n");
return 0;
+ found_issuer_check_skid:
+ /* We matched issuer + serialNumber, but if there's an
+ * authKeyId.keyId, that must match the CA subjKeyId also.
+ */
+ if (x509->akid_skid &&
+ !asymmetric_key_id_same(p->skid, x509->akid_skid)) {
+ pr_warn("Sig %u: X.509 chain contains auth-skid nonmatch (%u->%u)\n",
+ sinfo->index, x509->index, p->index);
+ return -EKEYREJECTED;
+ }
found_issuer:
pr_debug("- subject %s\n", p->subject);
if (p->seen) {
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index bb55d6074d5f..6b060b290e77 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -65,23 +65,37 @@ __setup("ca_keys=", ca_keys_setup);
/**
* x509_request_asymmetric_key - Request a key by X.509 certificate params.
* @keyring: The keys to search.
- * @kid: The key ID.
+ * @id: The issuer & serialNumber to look for or NULL.
+ * @skid: The subjectKeyIdentifier to look for or NULL.
* @partial: Use partial match if true, exact if false.
*
- * Find a key in the given keyring by subject name and key ID. These might,
- * for instance, be the issuer name and the authority key ID of an X.509
- * certificate that needs to be verified.
+ * 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.
*/
struct key *x509_request_asymmetric_key(struct key *keyring,
- const struct asymmetric_key_id *kid,
+ const struct asymmetric_key_id *id,
+ const struct asymmetric_key_id *skid,
bool partial)
{
- key_ref_t key;
- char *id, *p;
-
+ struct key *key;
+ key_ref_t ref;
+ const char *lookup;
+ char *req, *p;
+ int len;
+
+ if (id) {
+ lookup = id->data;
+ len = id->len;
+ } else {
+ lookup = skid->data;
+ len = skid->len;
+ }
+
/* Construct an identifier "id:<keyid>". */
- p = id = kmalloc(2 + 1 + kid->len * 2 + 1, GFP_KERNEL);
- if (!id)
+ p = req = kmalloc(2 + 1 + len * 2 + 1, GFP_KERNEL);
+ if (!req)
return ERR_PTR(-ENOMEM);
if (partial) {
@@ -92,32 +106,48 @@ struct key *x509_request_asymmetric_key(struct key *keyring,
*p++ = 'x';
}
*p++ = ':';
- p = bin2hex(p, kid->data, kid->len);
+ p = bin2hex(p, lookup, len);
*p = 0;
- pr_debug("Look up: \"%s\"\n", id);
+ pr_debug("Look up: \"%s\"\n", req);
- key = keyring_search(make_key_ref(keyring, 1),
- &key_type_asymmetric, id);
- if (IS_ERR(key))
- pr_debug("Request for key '%s' err %ld\n", id, PTR_ERR(key));
- kfree(id);
+ ref = keyring_search(make_key_ref(keyring, 1),
+ &key_type_asymmetric, req);
+ if (IS_ERR(ref))
+ pr_debug("Request for key '%s' err %ld\n", req, PTR_ERR(ref));
+ kfree(req);
- if (IS_ERR(key)) {
- switch (PTR_ERR(key)) {
+ if (IS_ERR(ref)) {
+ switch (PTR_ERR(ref)) {
/* Hide some search errors */
case -EACCES:
case -ENOTDIR:
case -EAGAIN:
return ERR_PTR(-ENOKEY);
default:
- return ERR_CAST(key);
+ return ERR_CAST(ref);
+ }
+ }
+
+ key = key_ref_to_ptr(ref);
+ if (id && skid) {
+ const struct asymmetric_key_ids *kids = asymmetric_key_ids(key);
+ if (!kids->id[1]) {
+ pr_debug("issuer+serial match, but expected SKID missing\n");
+ goto reject;
+ }
+ if (!asymmetric_key_id_same(skid, kids->id[1])) {
+ pr_debug("issuer+serial match, but SKID does not\n");
+ goto reject;
}
}
+
+ pr_devel("<==%s() = 0 [%x]\n", __func__, key_serial(key));
+ return key;
- pr_devel("<==%s() = 0 [%x]\n", __func__,
- key_serial(key_ref_to_ptr(key)));
- return key_ref_to_ptr(key);
+reject:
+ key_put(key);
+ return ERR_PTR(-EKEYREJECTED);
}
EXPORT_SYMBOL_GPL(x509_request_asymmetric_key);
@@ -230,7 +260,8 @@ static int x509_validate_trust(struct x509_certificate *cert,
if (ca_keyid && !asymmetric_key_id_partial(cert->akid_skid, ca_keyid))
return -EPERM;
- key = x509_request_asymmetric_key(trust_keyring, cert->akid_skid,
+ key = x509_request_asymmetric_key(trust_keyring,
+ cert->akid_id, cert->akid_skid,
false);
if (!IS_ERR(key)) {
if (!use_builtin_keys
@@ -287,8 +318,9 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
cert->pub->id_type = PKEY_ID_X509;
/* Check the signature on the key if it appears to be self-signed */
- if (!cert->akid_skid ||
- asymmetric_key_id_same(cert->skid, cert->akid_skid)) {
+ if ((!cert->akid_skid && !cert->akid_id) ||
+ asymmetric_key_id_same(cert->skid, cert->akid_skid) ||
+ asymmetric_key_id_same(cert->id, cert->akid_id)) {
ret = x509_check_signature(cert->pub, cert); /* self-signed */
if (ret < 0)
goto error_free_cert;
diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index 54add2069901..b6f27a240856 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -101,7 +101,8 @@ extern int verify_signature(const struct key *key,
struct asymmetric_key_id;
extern struct key *x509_request_asymmetric_key(struct key *keyring,
- const struct asymmetric_key_id *kid,
+ const struct asymmetric_key_id *id,
+ const struct asymmetric_key_id *skid,
bool partial);
#endif /* _LINUX_PUBLIC_KEY_H */
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.