// SPDX-License-Identifier: GPL-2.0-only/* * Copyright (C) 2011 Intel Corporation * * Author: * Dmitry Kasatkin <dmitry.kasatkin@intel.com> */ #include <linux/err.h>#include <linux/sched.h>#include <linux/slab.h>#include <linux/cred.h>#include <linux/kernel_read_file.h>#include <linux/key-type.h>#include <linux/digsig.h>#include <linux/vmalloc.h>#include <crypto/public_key.h>#include <keys/system_keyring.h> #include "integrity.h" static struct key *keyring[INTEGRITY_KEYRING_MAX]; static const char * const keyring_name[INTEGRITY_KEYRING_MAX] = {#ifndef CONFIG_INTEGRITY_TRUSTED_KEYRING	"_evm",	"_ima",#else	".evm",	".ima",#endif	".platform",	".machine",}; #ifdef CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY#define restrict_link_to_ima restrict_link_by_digsig_builtin_and_secondary#else#define restrict_link_to_ima restrict_link_by_digsig_builtin#endif static struct key *integrity_keyring_from_id(const unsigned int id){	if (id >= INTEGRITY_KEYRING_MAX)		return ERR_PTR(-EINVAL); 	if (!keyring[id]) {		keyring[id] =			request_key(&key_type_keyring, keyring_name[id], NULL);		if (IS_ERR(keyring[id])) {			int err = PTR_ERR(keyring[id]);			pr_err("no %s keyring: %d\n", keyring_name[id], err);			keyring[id] = NULL;			return ERR_PTR(err);		}	} 	return keyring[id];} int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,			    const char *digest, int digestlen, u8 algo){	struct key *keyring; 	if (siglen < 2)		return -EINVAL; 	keyring = integrity_keyring_from_id(id);	if (IS_ERR(keyring))		return PTR_ERR(keyring); 	switch (sig[1]) {	case 1:		/* v1 API expect signature without xattr type */		return digsig_verify(keyring, sig + 1, siglen - 1, digest,				     digestlen);	case 2: /* regular file data hash based signature */		return asymmetric_verify(keyring, sig, siglen, digest,					    digestlen);	case 3: /* struct ima_file_id data based signature */		return asymmetric_verify_v3(keyring, sig, siglen, digest,					    digestlen, algo);	} 	return -EOPNOTSUPP;} int integrity_modsig_verify(const unsigned int id, const struct modsig *modsig){	struct key *keyring; 	keyring = integrity_keyring_from_id(id);	if (IS_ERR(keyring))		return PTR_ERR(keyring); 	return ima_modsig_verify(keyring, modsig);} static int __init __integrity_init_keyring(const unsigned int id,					   key_perm_t perm,					   struct key_restriction *restriction){	const struct cred *cred = current_cred();	int err = 0; 	keyring[id] = keyring_alloc(keyring_name[id], KUIDT_INIT(0),				    KGIDT_INIT(0), cred, perm,				    KEY_ALLOC_NOT_IN_QUOTA, restriction, NULL);	if (IS_ERR(keyring[id])) {		err = PTR_ERR(keyring[id]);		pr_info("Can't allocate %s keyring (%d)\n",			keyring_name[id], err);		keyring[id] = NULL;	} else {		if (id == INTEGRITY_KEYRING_PLATFORM)			set_platform_trusted_keys(keyring[id]);		if (id == INTEGRITY_KEYRING_MACHINE && imputed_trust_enabled())			set_machine_trusted_keys(keyring[id]);		if (id == INTEGRITY_KEYRING_IMA)			load_module_cert(keyring[id]);	} 	return err;} int __init integrity_init_keyring(const unsigned int id){	struct key_restriction *restriction;	key_perm_t perm;	int ret; 	perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW		| KEY_USR_READ | KEY_USR_SEARCH; 	if (id == INTEGRITY_KEYRING_PLATFORM ||	    (id == INTEGRITY_KEYRING_MACHINE &&	    !IS_ENABLED(CONFIG_INTEGRITY_CA_MACHINE_KEYRING))) {		restriction = NULL;		goto out;	} 	if (!IS_ENABLED(CONFIG_INTEGRITY_TRUSTED_KEYRING))		return 0; 	restriction = kzalloc_obj(struct key_restriction);	if (!restriction)		return -ENOMEM; 	if (id == INTEGRITY_KEYRING_MACHINE)		restriction->check = restrict_link_by_ca;	else		restriction->check = restrict_link_to_ima; 	/*	 * MOK keys can only be added through a read-only runtime services	 * UEFI variable during boot. No additional keys shall be allowed to	 * load into the machine keyring following init from userspace.	 */	if (id != INTEGRITY_KEYRING_MACHINE)		perm |= KEY_USR_WRITE; out:	ret = __integrity_init_keyring(id, perm, restriction);	if (ret)		kfree(restriction);	return ret;} static int __init integrity_add_key(const unsigned int id, const void *data,				    off_t size, key_perm_t perm){	key_ref_t key;	int rc = 0; 	if (!keyring[id])		return -EINVAL; 	key = key_create_or_update(make_key_ref(keyring[id], 1), "asymmetric",				   NULL, data, size, perm,				   KEY_ALLOC_NOT_IN_QUOTA);	if (IS_ERR(key)) {		rc = PTR_ERR(key);		if (id != INTEGRITY_KEYRING_MACHINE)			pr_err("Problem loading X.509 certificate %d\n", rc);	} else {		pr_notice("Loaded X.509 cert '%s'\n",			  key_ref_to_ptr(key)->description);		key_ref_put(key);	} 	return rc; } int __init integrity_load_x509(const unsigned int id, const char *path){	void *data = NULL;	size_t size;	int rc;	key_perm_t perm; 	rc = kernel_read_file_from_path(path, 0, &data, INT_MAX, NULL,					READING_X509_CERTIFICATE);	if (rc < 0) {		pr_err("Unable to open file: %s (%d)", path, rc);		return rc;	}	size = rc; 	perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ; 	pr_info("Loading X.509 certificate: %s\n", path);	rc = integrity_add_key(id, (const void *)data, size, perm); 	vfree(data);	return rc;} int __init integrity_load_cert(const unsigned int id, const char *source,			       const void *data, size_t len, key_perm_t perm){	if (!data)		return -EINVAL; 	pr_info("Loading X.509 certificate: %s\n", source);	return integrity_add_key(id, data, len, perm);}