1 files changed, 82 insertions, 215 deletions

diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 733c046..fb73229 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -20,256 +20,133 @@
 #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;
 }
 
 /*
@@ -291,34 +168,22 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
 	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 */
@@ -353,6 +218,7 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
 	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;
 
@@ -360,6 +226,7 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
 	cert->pub = NULL;
 	cert->id = NULL;
 	cert->skid = NULL;
+	cert->sig = NULL;
 	desc = NULL;
 	ret = 0;