#include "asymmetric_keys.h"
#include "x509_parser.h"
-static bool use_builtin_keys;
-static struct asymmetric_key_id *ca_keyid;
-
-#ifndef MODULE
-static struct {
- struct asymmetric_key_id id;
- unsigned char data[10];
-} cakey;
-
-static int __init ca_keys_setup(char *str)
-{
- if (!str) /* default system keyring */
- return 1;
-
- if (strncmp(str, "id:", 3) == 0) {
- struct asymmetric_key_id *p = &cakey.id;
- size_t hexlen = (strlen(str) - 3) / 2;
- int ret;
-
- if (hexlen == 0 || hexlen > sizeof(cakey.data)) {
- pr_err("Missing or invalid ca_keys id\n");
- return 1;
- }
-
- ret = __asymmetric_key_hex_to_key_id(str + 3, p, hexlen);
- if (ret < 0)
- pr_err("Unparsable ca_keys id hex string\n");
- else
- ca_keyid = p; /* owner key 'id:xxxxxx' */
- } else if (strcmp(str, "builtin") == 0) {
- use_builtin_keys = true;
- }
-
- return 1;
-}
-__setup("ca_keys=", ca_keys_setup);
-#endif
-
-/**
- * x509_request_asymmetric_key - Request a key by X.509 certificate params.
- * @keyring: The keys to search.
- * @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 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 *id,
- const struct asymmetric_key_id *skid,
- bool partial)
-{
- 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 = req = kmalloc(2 + 1 + len * 2 + 1, GFP_KERNEL);
- if (!req)
- return ERR_PTR(-ENOMEM);
-
- if (partial) {
- *p++ = 'i';
- *p++ = 'd';
- } else {
- *p++ = 'e';
- *p++ = 'x';
- }
- *p++ = ':';
- p = bin2hex(p, lookup, len);
- *p = 0;
-
- pr_debug("Look up: \"%s\"\n", req);
-
- 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(ref)) {
- switch (PTR_ERR(ref)) {
- /* Hide some search errors */
- case -EACCES:
- case -ENOTDIR:
- case -EAGAIN:
- return ERR_PTR(-ENOKEY);
- default:
- 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;
-
-reject:
- key_put(key);
- return ERR_PTR(-EKEYREJECTED);
-}
-EXPORT_SYMBOL_GPL(x509_request_asymmetric_key);
-
/*
* Set up the signature parameters in an X.509 certificate. This involves
* digesting the signed data and extracting the signature.
*/
int x509_get_sig_params(struct x509_certificate *cert)
{
+ struct public_key_signature *sig = cert->sig;
struct crypto_shash *tfm;
struct shash_desc *desc;
- size_t digest_size, desc_size;
- void *digest;
+ size_t desc_size;
int ret;
pr_devel("==>%s()\n", __func__);
- if (cert->unsupported_crypto)
- return -ENOPKG;
- if (cert->sig.s)
+ if (!cert->pub->pkey_algo)
+ cert->unsupported_key = true;
+
+ if (!sig->pkey_algo)
+ cert->unsupported_sig = true;
+
+ /* We check the hash if we can - even if we can't then verify it */
+ if (!sig->hash_algo) {
+ cert->unsupported_sig = true;
return 0;
+ }
- cert->sig.s = kmemdup(cert->raw_sig, cert->raw_sig_size,
- GFP_KERNEL);
- if (!cert->sig.s)
+ sig->s = kmemdup(cert->raw_sig, cert->raw_sig_size, GFP_KERNEL);
+ if (!sig->s)
return -ENOMEM;
- cert->sig.s_size = cert->raw_sig_size;
+ sig->s_size = cert->raw_sig_size;
/* Allocate the hashing algorithm we're going to need and find out how
* big the hash operational data will be.
*/
- tfm = crypto_alloc_shash(cert->sig.hash_algo, 0, 0);
+ tfm = crypto_alloc_shash(sig->hash_algo, 0, 0);
if (IS_ERR(tfm)) {
if (PTR_ERR(tfm) == -ENOENT) {
- cert->unsupported_crypto = true;
- return -ENOPKG;
+ cert->unsupported_sig = true;
+ return 0;
}
return PTR_ERR(tfm);
}
desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
- digest_size = crypto_shash_digestsize(tfm);
+ sig->digest_size = crypto_shash_digestsize(tfm);
- /* We allocate the hash operational data storage on the end of the
- * digest storage space.
- */
ret = -ENOMEM;
- digest = kzalloc(ALIGN(digest_size, __alignof__(*desc)) + desc_size,
- GFP_KERNEL);
- if (!digest)
+ sig->digest = kmalloc(sig->digest_size, GFP_KERNEL);
+ if (!sig->digest)
goto error;
- cert->sig.digest = digest;
- cert->sig.digest_size = digest_size;
+ desc = kzalloc(desc_size, GFP_KERNEL);
+ if (!desc)
+ goto error;
- desc = PTR_ALIGN(digest + digest_size, __alignof__(*desc));
desc->tfm = tfm;
desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
ret = crypto_shash_init(desc);
if (ret < 0)
- goto error;
+ goto error_2;
might_sleep();
- ret = crypto_shash_finup(desc, cert->tbs, cert->tbs_size, digest);
+ ret = crypto_shash_finup(desc, cert->tbs, cert->tbs_size, sig->digest);
+
+error_2:
+ kfree(desc);
error:
crypto_free_shash(tfm);
pr_devel("<==%s() = %d\n", __func__, ret);
return ret;
}
-EXPORT_SYMBOL_GPL(x509_get_sig_params);
/*
- * Check the signature on a certificate using the provided public key
+ * Check for self-signedness in an X.509 cert and if found, check the signature
+ * immediately if we can.
*/
-int x509_check_signature(const struct public_key *pub,
- struct x509_certificate *cert)
+int x509_check_for_self_signed(struct x509_certificate *cert)
{
- int ret;
+ int ret = 0;
pr_devel("==>%s()\n", __func__);
- ret = x509_get_sig_params(cert);
- if (ret < 0)
- return ret;
+ if (cert->raw_subject_size != cert->raw_issuer_size ||
+ memcmp(cert->raw_subject, cert->raw_issuer,
+ cert->raw_issuer_size) != 0)
+ goto not_self_signed;
+
+ if (cert->sig->auth_ids[0] || cert->sig->auth_ids[1]) {
+ /* If the AKID is present it may have one or two parts. If
+ * both are supplied, both must match.
+ */
+ bool a = asymmetric_key_id_same(cert->skid, cert->sig->auth_ids[1]);
+ bool b = asymmetric_key_id_same(cert->id, cert->sig->auth_ids[0]);
+
+ if (!a && !b)
+ goto not_self_signed;
+
+ ret = -EKEYREJECTED;
+ if (((a && !b) || (b && !a)) &&
+ cert->sig->auth_ids[0] && cert->sig->auth_ids[1])
+ goto out;
+ }
- ret = public_key_verify_signature(pub, &cert->sig);
- if (ret == -ENOPKG)
- cert->unsupported_crypto = true;
- pr_debug("Cert Verification: %d\n", ret);
- return ret;
-}
-EXPORT_SYMBOL_GPL(x509_check_signature);
+ ret = -EKEYREJECTED;
+ if (cert->pub->pkey_algo != cert->sig->pkey_algo)
+ goto out;
-/*
- * 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_key_id_partial(cert->akid_skid, ca_keyid))
- return -EPERM;
-
- key = x509_request_asymmetric_key(trust_keyring,
- cert->akid_id, cert->akid_skid,
- false);
- if (!IS_ERR(key)) {
- if (!use_builtin_keys
- || test_bit(KEY_FLAG_BUILTIN, &key->flags))
- ret = x509_check_signature(key->payload.data[asym_crypto],
- cert);
- key_put(key);
+ ret = public_key_verify_signature(cert->pub, cert->sig);
+ if (ret < 0) {
+ if (ret == -ENOPKG) {
+ cert->unsupported_sig = true;
+ ret = 0;
+ }
+ goto out;
}
+
+ pr_devel("Cert Self-signature verified");
+ cert->self_signed = true;
+
+out:
+ pr_devel("<==%s() = %d\n", __func__, ret);
return ret;
+
+not_self_signed:
+ pr_devel("<==%s() = 0 [not]\n", __func__);
+ return 0;
}
/*
pr_devel("Cert Issuer: %s\n", cert->issuer);
pr_devel("Cert Subject: %s\n", cert->subject);
- if (!cert->pub->pkey_algo ||
- !cert->sig.pkey_algo ||
- !cert->sig.hash_algo) {
+ if (cert->unsupported_key) {
ret = -ENOPKG;
goto error_free_cert;
}
pr_devel("Cert Key Algo: %s\n", cert->pub->pkey_algo);
pr_devel("Cert Valid period: %lld-%lld\n", cert->valid_from, cert->valid_to);
- pr_devel("Cert Signature: %s + %s\n",
- cert->sig.pkey_algo,
- cert->sig.hash_algo);
cert->pub->id_type = "X509";
- /* Check the signature on the key if it appears to be self-signed */
- 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;
- } else if (!prep->trusted) {
- ret = x509_validate_trust(cert, get_system_trusted_keyring());
- if (ret)
- ret = x509_validate_trust(cert, get_ima_mok_keyring());
- if (!ret)
- prep->trusted = 1;
+ if (cert->unsupported_sig) {
+ public_key_signature_free(cert->sig);
+ cert->sig = NULL;
+ } else {
+ pr_devel("Cert Signature: %s + %s\n",
+ cert->sig->pkey_algo, cert->sig->hash_algo);
}
/* Propose a description */
prep->payload.data[asym_subtype] = &public_key_subtype;
prep->payload.data[asym_key_ids] = kids;
prep->payload.data[asym_crypto] = cert->pub;
+ prep->payload.data[asym_auth] = cert->sig;
prep->description = desc;
prep->quotalen = 100;
cert->pub = NULL;
cert->id = NULL;
cert->skid = NULL;
+ cert->sig = NULL;
desc = NULL;
ret = 0;
projects / cascardo / linux.git / blobdiff