Re: [PATCH v9 1/4] KEYS: trusted: Add generic trusted keys framework

[Jarkko Sakkinen <jarkko@kernel.org>]

On Mon, Mar 01, 2021 at 06:41:24PM +0530, Sumit Garg wrote:
> Current trusted keys framework is tightly coupled to use TPM device as
> an underlying implementation which makes it difficult for implementations
> like Trusted Execution Environment (TEE) etc. to provide trusted keys
> support in case platform doesn't posses a TPM device.
> 
> Add a generic trusted keys framework where underlying implementations
> can be easily plugged in. Create struct trusted_key_ops to achieve this,
> which contains necessary functions of a backend.
> 
> Also, define a module parameter in order to select a particular trust
> source in case a platform support multiple trust sources. In case its
> not specified then implementation itetrates through trust sources list
> starting with TPM and assign the first trust source as a backend which
> has initiazed successfully during iteration.
> 
> Note that current implementation only supports a single trust source at
> runtime which is either selectable at compile time or during boot via
> aforementioned module parameter.
> 
> Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> Signed-off-by: Sumit Garg <sumit.garg@linaro.org>

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

/Jarkko

> ---
>  .../admin-guide/kernel-parameters.txt         |  12 +
>  include/keys/trusted-type.h                   |  53 +++
>  include/keys/trusted_tpm.h                    |  29 +-
>  security/keys/trusted-keys/Makefile           |   1 +
>  security/keys/trusted-keys/trusted_core.c     | 354 +++++++++++++++++
>  security/keys/trusted-keys/trusted_tpm1.c     | 366 ++++--------------
>  6 files changed, 497 insertions(+), 318 deletions(-)
>  create mode 100644 security/keys/trusted-keys/trusted_core.c
> 
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 0ac883777318..fbc828994b06 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -5459,6 +5459,18 @@
>  			See Documentation/admin-guide/mm/transhuge.rst
>  			for more details.
>  
> +	trusted.source=	[KEYS]
> +			Format: <string>
> +			This parameter identifies the trust source as a backend
> +			for trusted keys implementation. Supported trust
> +			sources:
> +			- "tpm"
> +			- "tee"
> +			If not specified then it defaults to iterating through
> +			the trust source list starting with TPM and assigns the
> +			first trust source as a backend which is initialized
> +			successfully during iteration.
> +
>  	tsc=		Disable clocksource stability checks for TSC.
>  			Format: <string>
>  			[x86] reliable: mark tsc clocksource as reliable, this
> diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h
> index a94c03a61d8f..24016898ca41 100644
> --- a/include/keys/trusted-type.h
> +++ b/include/keys/trusted-type.h
> @@ -11,6 +11,12 @@
>  #include <linux/rcupdate.h>
>  #include <linux/tpm.h>
>  
> +#ifdef pr_fmt
> +#undef pr_fmt
> +#endif
> +
> +#define pr_fmt(fmt) "trusted_key: " fmt
> +
>  #define MIN_KEY_SIZE			32
>  #define MAX_KEY_SIZE			128
>  #define MAX_BLOB_SIZE			512
> @@ -40,6 +46,53 @@ struct trusted_key_options {
>  	uint32_t policyhandle;
>  };
>  
> +struct trusted_key_ops {
> +	/*
> +	 * flag to indicate if trusted key implementation supports migration
> +	 * or not.
> +	 */
> +	unsigned char migratable;
> +
> +	/* Initialize key interface. */
> +	int (*init)(void);
> +
> +	/* Seal a key. */
> +	int (*seal)(struct trusted_key_payload *p, char *datablob);
> +
> +	/* Unseal a key. */
> +	int (*unseal)(struct trusted_key_payload *p, char *datablob);
> +
> +	/* Get a randomized key. */
> +	int (*get_random)(unsigned char *key, size_t key_len);
> +
> +	/* Exit key interface. */
> +	void (*exit)(void);
> +};
> +
> +struct trusted_key_source {
> +	char *name;
> +	struct trusted_key_ops *ops;
> +};
> +
>  extern struct key_type key_type_trusted;
>  
> +#define TRUSTED_DEBUG 0
> +
> +#if TRUSTED_DEBUG
> +static inline void dump_payload(struct trusted_key_payload *p)
> +{
> +	pr_info("key_len %d\n", p->key_len);
> +	print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE,
> +		       16, 1, p->key, p->key_len, 0);
> +	pr_info("bloblen %d\n", p->blob_len);
> +	print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE,
> +		       16, 1, p->blob, p->blob_len, 0);
> +	pr_info("migratable %d\n", p->migratable);
> +}
> +#else
> +static inline void dump_payload(struct trusted_key_payload *p)
> +{
> +}
> +#endif
> +
>  #endif /* _KEYS_TRUSTED_TYPE_H */
> diff --git a/include/keys/trusted_tpm.h b/include/keys/trusted_tpm.h
> index a56d8e1298f2..7769b726863a 100644
> --- a/include/keys/trusted_tpm.h
> +++ b/include/keys/trusted_tpm.h
> @@ -16,6 +16,8 @@
>  #define LOAD32N(buffer, offset)	(*(uint32_t *)&buffer[offset])
>  #define LOAD16(buffer, offset)	(ntohs(*(uint16_t *)&buffer[offset]))
>  
> +extern struct trusted_key_ops trusted_key_tpm_ops;
> +
>  struct osapsess {
>  	uint32_t handle;
>  	unsigned char secret[SHA1_DIGEST_SIZE];
> @@ -52,30 +54,19 @@ int tpm2_unseal_trusted(struct tpm_chip *chip,
>  #if TPM_DEBUG
>  static inline void dump_options(struct trusted_key_options *o)
>  {
> -	pr_info("trusted_key: sealing key type %d\n", o->keytype);
> -	pr_info("trusted_key: sealing key handle %0X\n", o->keyhandle);
> -	pr_info("trusted_key: pcrlock %d\n", o->pcrlock);
> -	pr_info("trusted_key: pcrinfo %d\n", o->pcrinfo_len);
> +	pr_info("sealing key type %d\n", o->keytype);
> +	pr_info("sealing key handle %0X\n", o->keyhandle);
> +	pr_info("pcrlock %d\n", o->pcrlock);
> +	pr_info("pcrinfo %d\n", o->pcrinfo_len);
>  	print_hex_dump(KERN_INFO, "pcrinfo ", DUMP_PREFIX_NONE,
>  		       16, 1, o->pcrinfo, o->pcrinfo_len, 0);
>  }
>  
> -static inline void dump_payload(struct trusted_key_payload *p)
> -{
> -	pr_info("trusted_key: key_len %d\n", p->key_len);
> -	print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE,
> -		       16, 1, p->key, p->key_len, 0);
> -	pr_info("trusted_key: bloblen %d\n", p->blob_len);
> -	print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE,
> -		       16, 1, p->blob, p->blob_len, 0);
> -	pr_info("trusted_key: migratable %d\n", p->migratable);
> -}
> -
>  static inline void dump_sess(struct osapsess *s)
>  {
>  	print_hex_dump(KERN_INFO, "trusted-key: handle ", DUMP_PREFIX_NONE,
>  		       16, 1, &s->handle, 4, 0);
> -	pr_info("trusted-key: secret:\n");
> +	pr_info("secret:\n");
>  	print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE,
>  		       16, 1, &s->secret, SHA1_DIGEST_SIZE, 0);
>  	pr_info("trusted-key: enonce:\n");
> @@ -87,7 +78,7 @@ static inline void dump_tpm_buf(unsigned char *buf)
>  {
>  	int len;
>  
> -	pr_info("\ntrusted-key: tpm buffer\n");
> +	pr_info("\ntpm buffer\n");
>  	len = LOAD32(buf, TPM_SIZE_OFFSET);
>  	print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, 16, 1, buf, len, 0);
>  }
> @@ -96,10 +87,6 @@ static inline void dump_options(struct trusted_key_options *o)
>  {
>  }
>  
> -static inline void dump_payload(struct trusted_key_payload *p)
> -{
> -}
> -
>  static inline void dump_sess(struct osapsess *s)
>  {
>  }
> diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile
> index 7b73cebbb378..49e3bcfe704f 100644
> --- a/security/keys/trusted-keys/Makefile
> +++ b/security/keys/trusted-keys/Makefile
> @@ -4,5 +4,6 @@
>  #
>  
>  obj-$(CONFIG_TRUSTED_KEYS) += trusted.o
> +trusted-y += trusted_core.o
>  trusted-y += trusted_tpm1.o
>  trusted-y += trusted_tpm2.o
> diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c
> new file mode 100644
> index 000000000000..0db86b44605d
> --- /dev/null
> +++ b/security/keys/trusted-keys/trusted_core.c
> @@ -0,0 +1,354 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2010 IBM Corporation
> + * Copyright (c) 2019-2021, Linaro Limited
> + *
> + * See Documentation/security/keys/trusted-encrypted.rst
> + */
> +
> +#include <keys/user-type.h>
> +#include <keys/trusted-type.h>
> +#include <keys/trusted_tpm.h>
> +#include <linux/capability.h>
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/key-type.h>
> +#include <linux/module.h>
> +#include <linux/parser.h>
> +#include <linux/rcupdate.h>
> +#include <linux/slab.h>
> +#include <linux/static_call.h>
> +#include <linux/string.h>
> +#include <linux/uaccess.h>
> +
> +static char *trusted_key_source;
> +module_param_named(source, trusted_key_source, charp, 0);
> +MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)");
> +
> +static const struct trusted_key_source trusted_key_sources[] = {
> +#if defined(CONFIG_TCG_TPM)
> +	{ "tpm", &trusted_key_tpm_ops },
> +#endif
> +};
> +
> +DEFINE_STATIC_CALL_NULL(trusted_key_init, *trusted_key_sources[0].ops->init);
> +DEFINE_STATIC_CALL_NULL(trusted_key_seal, *trusted_key_sources[0].ops->seal);
> +DEFINE_STATIC_CALL_NULL(trusted_key_unseal,
> +			*trusted_key_sources[0].ops->unseal);
> +DEFINE_STATIC_CALL_NULL(trusted_key_get_random,
> +			*trusted_key_sources[0].ops->get_random);
> +DEFINE_STATIC_CALL_NULL(trusted_key_exit, *trusted_key_sources[0].ops->exit);
> +static unsigned char migratable;
> +
> +enum {
> +	Opt_err,
> +	Opt_new, Opt_load, Opt_update,
> +};
> +
> +static const match_table_t key_tokens = {
> +	{Opt_new, "new"},
> +	{Opt_load, "load"},
> +	{Opt_update, "update"},
> +	{Opt_err, NULL}
> +};
> +
> +/*
> + * datablob_parse - parse the keyctl data and fill in the
> + *                  payload structure
> + *
> + * On success returns 0, otherwise -EINVAL.
> + */
> +static int datablob_parse(char *datablob, struct trusted_key_payload *p)
> +{
> +	substring_t args[MAX_OPT_ARGS];
> +	long keylen;
> +	int ret = -EINVAL;
> +	int key_cmd;
> +	char *c;
> +
> +	/* main command */
> +	c = strsep(&datablob, " \t");
> +	if (!c)
> +		return -EINVAL;
> +	key_cmd = match_token(c, key_tokens, args);
> +	switch (key_cmd) {
> +	case Opt_new:
> +		/* first argument is key size */
> +		c = strsep(&datablob, " \t");
> +		if (!c)
> +			return -EINVAL;
> +		ret = kstrtol(c, 10, &keylen);
> +		if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
> +			return -EINVAL;
> +		p->key_len = keylen;
> +		ret = Opt_new;
> +		break;
> +	case Opt_load:
> +		/* first argument is sealed blob */
> +		c = strsep(&datablob, " \t");
> +		if (!c)
> +			return -EINVAL;
> +		p->blob_len = strlen(c) / 2;
> +		if (p->blob_len > MAX_BLOB_SIZE)
> +			return -EINVAL;
> +		ret = hex2bin(p->blob, c, p->blob_len);
> +		if (ret < 0)
> +			return -EINVAL;
> +		ret = Opt_load;
> +		break;
> +	case Opt_update:
> +		ret = Opt_update;
> +		break;
> +	case Opt_err:
> +		return -EINVAL;
> +	}
> +	return ret;
> +}
> +
> +static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
> +{
> +	struct trusted_key_payload *p = NULL;
> +	int ret;
> +
> +	ret = key_payload_reserve(key, sizeof(*p));
> +	if (ret < 0)
> +		return p;
> +	p = kzalloc(sizeof(*p), GFP_KERNEL);
> +
> +	p->migratable = migratable;
> +
> +	return p;
> +}
> +
> +/*
> + * trusted_instantiate - create a new trusted key
> + *
> + * Unseal an existing trusted blob or, for a new key, get a
> + * random key, then seal and create a trusted key-type key,
> + * adding it to the specified keyring.
> + *
> + * On success, return 0. Otherwise return errno.
> + */
> +static int trusted_instantiate(struct key *key,
> +			       struct key_preparsed_payload *prep)
> +{
> +	struct trusted_key_payload *payload = NULL;
> +	size_t datalen = prep->datalen;
> +	char *datablob;
> +	int ret = 0;
> +	int key_cmd;
> +	size_t key_len;
> +
> +	if (datalen <= 0 || datalen > 32767 || !prep->data)
> +		return -EINVAL;
> +
> +	datablob = kmalloc(datalen + 1, GFP_KERNEL);
> +	if (!datablob)
> +		return -ENOMEM;
> +	memcpy(datablob, prep->data, datalen);
> +	datablob[datalen] = '\0';
> +
> +	payload = trusted_payload_alloc(key);
> +	if (!payload) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	key_cmd = datablob_parse(datablob, payload);
> +	if (key_cmd < 0) {
> +		ret = key_cmd;
> +		goto out;
> +	}
> +
> +	dump_payload(payload);
> +
> +	switch (key_cmd) {
> +	case Opt_load:
> +		ret = static_call(trusted_key_unseal)(payload, datablob);
> +		dump_payload(payload);
> +		if (ret < 0)
> +			pr_info("key_unseal failed (%d)\n", ret);
> +		break;
> +	case Opt_new:
> +		key_len = payload->key_len;
> +		ret = static_call(trusted_key_get_random)(payload->key,
> +							  key_len);
> +		if (ret < 0)
> +			goto out;
> +
> +		if (ret != key_len) {
> +			pr_info("key_create failed (%d)\n", ret);
> +			ret = -EIO;
> +			goto out;
> +		}
> +
> +		ret = static_call(trusted_key_seal)(payload, datablob);
> +		if (ret < 0)
> +			pr_info("key_seal failed (%d)\n", ret);
> +		break;
> +	default:
> +		ret = -EINVAL;
> +	}
> +out:
> +	kfree_sensitive(datablob);
> +	if (!ret)
> +		rcu_assign_keypointer(key, payload);
> +	else
> +		kfree_sensitive(payload);
> +	return ret;
> +}
> +
> +static void trusted_rcu_free(struct rcu_head *rcu)
> +{
> +	struct trusted_key_payload *p;
> +
> +	p = container_of(rcu, struct trusted_key_payload, rcu);
> +	kfree_sensitive(p);
> +}
> +
> +/*
> + * trusted_update - reseal an existing key with new PCR values
> + */
> +static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
> +{
> +	struct trusted_key_payload *p;
> +	struct trusted_key_payload *new_p;
> +	size_t datalen = prep->datalen;
> +	char *datablob;
> +	int ret = 0;
> +
> +	if (key_is_negative(key))
> +		return -ENOKEY;
> +	p = key->payload.data[0];
> +	if (!p->migratable)
> +		return -EPERM;
> +	if (datalen <= 0 || datalen > 32767 || !prep->data)
> +		return -EINVAL;
> +
> +	datablob = kmalloc(datalen + 1, GFP_KERNEL);
> +	if (!datablob)
> +		return -ENOMEM;
> +
> +	new_p = trusted_payload_alloc(key);
> +	if (!new_p) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	memcpy(datablob, prep->data, datalen);
> +	datablob[datalen] = '\0';
> +	ret = datablob_parse(datablob, new_p);
> +	if (ret != Opt_update) {
> +		ret = -EINVAL;
> +		kfree_sensitive(new_p);
> +		goto out;
> +	}
> +
> +	/* copy old key values, and reseal with new pcrs */
> +	new_p->migratable = p->migratable;
> +	new_p->key_len = p->key_len;
> +	memcpy(new_p->key, p->key, p->key_len);
> +	dump_payload(p);
> +	dump_payload(new_p);
> +
> +	ret = static_call(trusted_key_seal)(new_p, datablob);
> +	if (ret < 0) {
> +		pr_info("key_seal failed (%d)\n", ret);
> +		kfree_sensitive(new_p);
> +		goto out;
> +	}
> +
> +	rcu_assign_keypointer(key, new_p);
> +	call_rcu(&p->rcu, trusted_rcu_free);
> +out:
> +	kfree_sensitive(datablob);
> +	return ret;
> +}
> +
> +/*
> + * trusted_read - copy the sealed blob data to userspace in hex.
> + * On success, return to userspace the trusted key datablob size.
> + */
> +static long trusted_read(const struct key *key, char *buffer,
> +			 size_t buflen)
> +{
> +	const struct trusted_key_payload *p;
> +	char *bufp;
> +	int i;
> +
> +	p = dereference_key_locked(key);
> +	if (!p)
> +		return -EINVAL;
> +
> +	if (buffer && buflen >= 2 * p->blob_len) {
> +		bufp = buffer;
> +		for (i = 0; i < p->blob_len; i++)
> +			bufp = hex_byte_pack(bufp, p->blob[i]);
> +	}
> +	return 2 * p->blob_len;
> +}
> +
> +/*
> + * trusted_destroy - clear and free the key's payload
> + */
> +static void trusted_destroy(struct key *key)
> +{
> +	kfree_sensitive(key->payload.data[0]);
> +}
> +
> +struct key_type key_type_trusted = {
> +	.name = "trusted",
> +	.instantiate = trusted_instantiate,
> +	.update = trusted_update,
> +	.destroy = trusted_destroy,
> +	.describe = user_describe,
> +	.read = trusted_read,
> +};
> +EXPORT_SYMBOL_GPL(key_type_trusted);
> +
> +static int __init init_trusted(void)
> +{
> +	int i, ret = 0;
> +
> +	for (i = 0; i < ARRAY_SIZE(trusted_key_sources); i++) {
> +		if (trusted_key_source &&
> +		    strncmp(trusted_key_source, trusted_key_sources[i].name,
> +			    strlen(trusted_key_sources[i].name)))
> +			continue;
> +
> +		static_call_update(trusted_key_init,
> +				   trusted_key_sources[i].ops->init);
> +		static_call_update(trusted_key_seal,
> +				   trusted_key_sources[i].ops->seal);
> +		static_call_update(trusted_key_unseal,
> +				   trusted_key_sources[i].ops->unseal);
> +		static_call_update(trusted_key_get_random,
> +				   trusted_key_sources[i].ops->get_random);
> +		static_call_update(trusted_key_exit,
> +				   trusted_key_sources[i].ops->exit);
> +		migratable = trusted_key_sources[i].ops->migratable;
> +
> +		ret = static_call(trusted_key_init)();
> +		if (!ret)
> +			break;
> +	}
> +
> +	/*
> +	 * encrypted_keys.ko depends on successful load of this module even if
> +	 * trusted key implementation is not found.
> +	 */
> +	if (ret == -ENODEV)
> +		return 0;
> +
> +	return ret;
> +}
> +
> +static void __exit cleanup_trusted(void)
> +{
> +	static_call(trusted_key_exit)();
> +}
> +
> +late_initcall(init_trusted);
> +module_exit(cleanup_trusted);
> +
> +MODULE_LICENSE("GPL");
> diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c
> index 493eb91ed017..99172af30d27 100644
> --- a/security/keys/trusted-keys/trusted_tpm1.c
> +++ b/security/keys/trusted-keys/trusted_tpm1.c
> @@ -1,29 +1,22 @@
>  // SPDX-License-Identifier: GPL-2.0-only
>  /*
>   * Copyright (C) 2010 IBM Corporation
> - *
> - * Author:
> - * David Safford <safford@us.ibm.com>
> + * Copyright (c) 2019-2021, Linaro Limited
>   *
>   * See Documentation/security/keys/trusted-encrypted.rst
>   */
>  
>  #include <crypto/hash_info.h>
> -#include <linux/uaccess.h>
> -#include <linux/module.h>
>  #include <linux/init.h>
>  #include <linux/slab.h>
>  #include <linux/parser.h>
>  #include <linux/string.h>
>  #include <linux/err.h>
> -#include <keys/user-type.h>
>  #include <keys/trusted-type.h>
>  #include <linux/key-type.h>
> -#include <linux/rcupdate.h>
>  #include <linux/crypto.h>
>  #include <crypto/hash.h>
>  #include <crypto/sha1.h>
> -#include <linux/capability.h>
>  #include <linux/tpm.h>
>  #include <linux/tpm_command.h>
>  
> @@ -63,7 +56,7 @@ static int TSS_sha1(const unsigned char *data, unsigned int datalen,
>  
>  	sdesc = init_sdesc(hashalg);
>  	if (IS_ERR(sdesc)) {
> -		pr_info("trusted_key: can't alloc %s\n", hash_alg);
> +		pr_info("can't alloc %s\n", hash_alg);
>  		return PTR_ERR(sdesc);
>  	}
>  
> @@ -83,7 +76,7 @@ static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
>  
>  	sdesc = init_sdesc(hmacalg);
>  	if (IS_ERR(sdesc)) {
> -		pr_info("trusted_key: can't alloc %s\n", hmac_alg);
> +		pr_info("can't alloc %s\n", hmac_alg);
>  		return PTR_ERR(sdesc);
>  	}
>  
> @@ -136,7 +129,7 @@ int TSS_authhmac(unsigned char *digest, const unsigned char *key,
>  
>  	sdesc = init_sdesc(hashalg);
>  	if (IS_ERR(sdesc)) {
> -		pr_info("trusted_key: can't alloc %s\n", hash_alg);
> +		pr_info("can't alloc %s\n", hash_alg);
>  		return PTR_ERR(sdesc);
>  	}
>  
> @@ -212,7 +205,7 @@ int TSS_checkhmac1(unsigned char *buffer,
>  
>  	sdesc = init_sdesc(hashalg);
>  	if (IS_ERR(sdesc)) {
> -		pr_info("trusted_key: can't alloc %s\n", hash_alg);
> +		pr_info("can't alloc %s\n", hash_alg);
>  		return PTR_ERR(sdesc);
>  	}
>  	ret = crypto_shash_init(&sdesc->shash);
> @@ -305,7 +298,7 @@ static int TSS_checkhmac2(unsigned char *buffer,
>  
>  	sdesc = init_sdesc(hashalg);
>  	if (IS_ERR(sdesc)) {
> -		pr_info("trusted_key: can't alloc %s\n", hash_alg);
> +		pr_info("can't alloc %s\n", hash_alg);
>  		return PTR_ERR(sdesc);
>  	}
>  	ret = crypto_shash_init(&sdesc->shash);
> @@ -597,12 +590,12 @@ static int tpm_unseal(struct tpm_buf *tb,
>  	/* sessions for unsealing key and data */
>  	ret = oiap(tb, &authhandle1, enonce1);
>  	if (ret < 0) {
> -		pr_info("trusted_key: oiap failed (%d)\n", ret);
> +		pr_info("oiap failed (%d)\n", ret);
>  		return ret;
>  	}
>  	ret = oiap(tb, &authhandle2, enonce2);
>  	if (ret < 0) {
> -		pr_info("trusted_key: oiap failed (%d)\n", ret);
> +		pr_info("oiap failed (%d)\n", ret);
>  		return ret;
>  	}
>  
> @@ -612,7 +605,7 @@ static int tpm_unseal(struct tpm_buf *tb,
>  		return ret;
>  
>  	if (ret != TPM_NONCE_SIZE) {
> -		pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
> +		pr_info("tpm_get_random failed (%d)\n", ret);
>  		return -EIO;
>  	}
>  	ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
> @@ -641,7 +634,7 @@ static int tpm_unseal(struct tpm_buf *tb,
>  
>  	ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
>  	if (ret < 0) {
> -		pr_info("trusted_key: authhmac failed (%d)\n", ret);
> +		pr_info("authhmac failed (%d)\n", ret);
>  		return ret;
>  	}
>  
> @@ -653,7 +646,7 @@ static int tpm_unseal(struct tpm_buf *tb,
>  			     *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
>  			     0);
>  	if (ret < 0) {
> -		pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret);
> +		pr_info("TSS_checkhmac2 failed (%d)\n", ret);
>  		return ret;
>  	}
>  	memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
> @@ -680,7 +673,7 @@ static int key_seal(struct trusted_key_payload *p,
>  		       p->key, p->key_len + 1, p->blob, &p->blob_len,
>  		       o->blobauth, o->pcrinfo, o->pcrinfo_len);
>  	if (ret < 0)
> -		pr_info("trusted_key: srkseal failed (%d)\n", ret);
> +		pr_info("srkseal failed (%d)\n", ret);
>  
>  	tpm_buf_destroy(&tb);
>  	return ret;
> @@ -702,7 +695,7 @@ static int key_unseal(struct trusted_key_payload *p,
>  	ret = tpm_unseal(&tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
>  			 o->blobauth, p->key, &p->key_len);
>  	if (ret < 0)
> -		pr_info("trusted_key: srkunseal failed (%d)\n", ret);
> +		pr_info("srkunseal failed (%d)\n", ret);
>  	else
>  		/* pull migratable flag out of sealed key */
>  		p->migratable = p->key[--p->key_len];
> @@ -713,7 +706,6 @@ static int key_unseal(struct trusted_key_payload *p,
>  
>  enum {
>  	Opt_err,
> -	Opt_new, Opt_load, Opt_update,
>  	Opt_keyhandle, Opt_keyauth, Opt_blobauth,
>  	Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
>  	Opt_hash,
> @@ -722,9 +714,6 @@ enum {
>  };
>  
>  static const match_table_t key_tokens = {
> -	{Opt_new, "new"},
> -	{Opt_load, "load"},
> -	{Opt_update, "update"},
>  	{Opt_keyhandle, "keyhandle=%s"},
>  	{Opt_keyauth, "keyauth=%s"},
>  	{Opt_blobauth, "blobauth=%s"},
> @@ -822,7 +811,7 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
>  			if (i == HASH_ALGO__LAST)
>  				return -EINVAL;
>  			if  (!tpm2 && i != HASH_ALGO_SHA1) {
> -				pr_info("trusted_key: TPM 1.x only supports SHA-1.\n");
> +				pr_info("TPM 1.x only supports SHA-1.\n");
>  				return -EINVAL;
>  			}
>  			break;
> @@ -851,71 +840,6 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
>  	return 0;
>  }
>  
> -/*
> - * datablob_parse - parse the keyctl data and fill in the
> - * 		    payload and options structures
> - *
> - * On success returns 0, otherwise -EINVAL.
> - */
> -static int datablob_parse(char *datablob, struct trusted_key_payload *p,
> -			  struct trusted_key_options *o)
> -{
> -	substring_t args[MAX_OPT_ARGS];
> -	long keylen;
> -	int ret = -EINVAL;
> -	int key_cmd;
> -	char *c;
> -
> -	/* main command */
> -	c = strsep(&datablob, " \t");
> -	if (!c)
> -		return -EINVAL;
> -	key_cmd = match_token(c, key_tokens, args);
> -	switch (key_cmd) {
> -	case Opt_new:
> -		/* first argument is key size */
> -		c = strsep(&datablob, " \t");
> -		if (!c)
> -			return -EINVAL;
> -		ret = kstrtol(c, 10, &keylen);
> -		if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
> -			return -EINVAL;
> -		p->key_len = keylen;
> -		ret = getoptions(datablob, p, o);
> -		if (ret < 0)
> -			return ret;
> -		ret = Opt_new;
> -		break;
> -	case Opt_load:
> -		/* first argument is sealed blob */
> -		c = strsep(&datablob, " \t");
> -		if (!c)
> -			return -EINVAL;
> -		p->blob_len = strlen(c) / 2;
> -		if (p->blob_len > MAX_BLOB_SIZE)
> -			return -EINVAL;
> -		ret = hex2bin(p->blob, c, p->blob_len);
> -		if (ret < 0)
> -			return -EINVAL;
> -		ret = getoptions(datablob, p, o);
> -		if (ret < 0)
> -			return ret;
> -		ret = Opt_load;
> -		break;
> -	case Opt_update:
> -		/* all arguments are options */
> -		ret = getoptions(datablob, p, o);
> -		if (ret < 0)
> -			return ret;
> -		ret = Opt_update;
> -		break;
> -	case Opt_err:
> -		return -EINVAL;
> -		break;
> -	}
> -	return ret;
> -}
> -
>  static struct trusted_key_options *trusted_options_alloc(void)
>  {
>  	struct trusted_key_options *options;
> @@ -936,252 +860,99 @@ static struct trusted_key_options *trusted_options_alloc(void)
>  	return options;
>  }
>  
> -static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
> +static int trusted_tpm_seal(struct trusted_key_payload *p, char *datablob)
>  {
> -	struct trusted_key_payload *p = NULL;
> -	int ret;
> -
> -	ret = key_payload_reserve(key, sizeof *p);
> -	if (ret < 0)
> -		return p;
> -	p = kzalloc(sizeof *p, GFP_KERNEL);
> -	if (p)
> -		p->migratable = 1; /* migratable by default */
> -	return p;
> -}
> -
> -/*
> - * trusted_instantiate - create a new trusted key
> - *
> - * Unseal an existing trusted blob or, for a new key, get a
> - * random key, then seal and create a trusted key-type key,
> - * adding it to the specified keyring.
> - *
> - * On success, return 0. Otherwise return errno.
> - */
> -static int trusted_instantiate(struct key *key,
> -			       struct key_preparsed_payload *prep)
> -{
> -	struct trusted_key_payload *payload = NULL;
>  	struct trusted_key_options *options = NULL;
> -	size_t datalen = prep->datalen;
> -	char *datablob;
>  	int ret = 0;
> -	int key_cmd;
> -	size_t key_len;
>  	int tpm2;
>  
>  	tpm2 = tpm_is_tpm2(chip);
>  	if (tpm2 < 0)
>  		return tpm2;
>  
> -	if (datalen <= 0 || datalen > 32767 || !prep->data)
> -		return -EINVAL;
> -
> -	datablob = kmalloc(datalen + 1, GFP_KERNEL);
> -	if (!datablob)
> -		return -ENOMEM;
> -	memcpy(datablob, prep->data, datalen);
> -	datablob[datalen] = '\0';
> -
>  	options = trusted_options_alloc();
> -	if (!options) {
> -		ret = -ENOMEM;
> -		goto out;
> -	}
> -	payload = trusted_payload_alloc(key);
> -	if (!payload) {
> -		ret = -ENOMEM;
> -		goto out;
> -	}
> +	if (!options)
> +		return -ENOMEM;
>  
> -	key_cmd = datablob_parse(datablob, payload, options);
> -	if (key_cmd < 0) {
> -		ret = key_cmd;
> +	ret = getoptions(datablob, p, options);
> +	if (ret < 0)
>  		goto out;
> -	}
> +	dump_options(options);
>  
>  	if (!options->keyhandle) {
>  		ret = -EINVAL;
>  		goto out;
>  	}
>  
> -	dump_payload(payload);
> -	dump_options(options);
> -
> -	switch (key_cmd) {
> -	case Opt_load:
> -		if (tpm2)
> -			ret = tpm2_unseal_trusted(chip, payload, options);
> -		else
> -			ret = key_unseal(payload, options);
> -		dump_payload(payload);
> -		dump_options(options);
> -		if (ret < 0)
> -			pr_info("trusted_key: key_unseal failed (%d)\n", ret);
> -		break;
> -	case Opt_new:
> -		key_len = payload->key_len;
> -		ret = tpm_get_random(chip, payload->key, key_len);
> -		if (ret < 0)
> -			goto out;
> +	if (tpm2)
> +		ret = tpm2_seal_trusted(chip, p, options);
> +	else
> +		ret = key_seal(p, options);
> +	if (ret < 0) {
> +		pr_info("key_seal failed (%d)\n", ret);
> +		goto out;
> +	}
>  
> -		if (ret != key_len) {
> -			pr_info("trusted_key: key_create failed (%d)\n", ret);
> -			ret = -EIO;
> +	if (options->pcrlock) {
> +		ret = pcrlock(options->pcrlock);
> +		if (ret < 0) {
> +			pr_info("pcrlock failed (%d)\n", ret);
>  			goto out;
>  		}
> -		if (tpm2)
> -			ret = tpm2_seal_trusted(chip, payload, options);
> -		else
> -			ret = key_seal(payload, options);
> -		if (ret < 0)
> -			pr_info("trusted_key: key_seal failed (%d)\n", ret);
> -		break;
> -	default:
> -		ret = -EINVAL;
> -		goto out;
>  	}
> -	if (!ret && options->pcrlock)
> -		ret = pcrlock(options->pcrlock);
>  out:
> -	kfree_sensitive(datablob);
>  	kfree_sensitive(options);
> -	if (!ret)
> -		rcu_assign_keypointer(key, payload);
> -	else
> -		kfree_sensitive(payload);
>  	return ret;
>  }
>  
> -static void trusted_rcu_free(struct rcu_head *rcu)
> -{
> -	struct trusted_key_payload *p;
> -
> -	p = container_of(rcu, struct trusted_key_payload, rcu);
> -	kfree_sensitive(p);
> -}
> -
> -/*
> - * trusted_update - reseal an existing key with new PCR values
> - */
> -static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
> +static int trusted_tpm_unseal(struct trusted_key_payload *p, char *datablob)
>  {
> -	struct trusted_key_payload *p;
> -	struct trusted_key_payload *new_p;
> -	struct trusted_key_options *new_o;
> -	size_t datalen = prep->datalen;
> -	char *datablob;
> +	struct trusted_key_options *options = NULL;
>  	int ret = 0;
> +	int tpm2;
>  
> -	if (key_is_negative(key))
> -		return -ENOKEY;
> -	p = key->payload.data[0];
> -	if (!p->migratable)
> -		return -EPERM;
> -	if (datalen <= 0 || datalen > 32767 || !prep->data)
> -		return -EINVAL;
> +	tpm2 = tpm_is_tpm2(chip);
> +	if (tpm2 < 0)
> +		return tpm2;
>  
> -	datablob = kmalloc(datalen + 1, GFP_KERNEL);
> -	if (!datablob)
> +	options = trusted_options_alloc();
> +	if (!options)
>  		return -ENOMEM;
> -	new_o = trusted_options_alloc();
> -	if (!new_o) {
> -		ret = -ENOMEM;
> -		goto out;
> -	}
> -	new_p = trusted_payload_alloc(key);
> -	if (!new_p) {
> -		ret = -ENOMEM;
> -		goto out;
> -	}
>  
> -	memcpy(datablob, prep->data, datalen);
> -	datablob[datalen] = '\0';
> -	ret = datablob_parse(datablob, new_p, new_o);
> -	if (ret != Opt_update) {
> -		ret = -EINVAL;
> -		kfree_sensitive(new_p);
> +	ret = getoptions(datablob, p, options);
> +	if (ret < 0)
>  		goto out;
> -	}
> +	dump_options(options);
>  
> -	if (!new_o->keyhandle) {
> +	if (!options->keyhandle) {
>  		ret = -EINVAL;
> -		kfree_sensitive(new_p);
>  		goto out;
>  	}
>  
> -	/* copy old key values, and reseal with new pcrs */
> -	new_p->migratable = p->migratable;
> -	new_p->key_len = p->key_len;
> -	memcpy(new_p->key, p->key, p->key_len);
> -	dump_payload(p);
> -	dump_payload(new_p);
> +	if (tpm2)
> +		ret = tpm2_unseal_trusted(chip, p, options);
> +	else
> +		ret = key_unseal(p, options);
> +	if (ret < 0)
> +		pr_info("key_unseal failed (%d)\n", ret);
>  
> -	ret = key_seal(new_p, new_o);
> -	if (ret < 0) {
> -		pr_info("trusted_key: key_seal failed (%d)\n", ret);
> -		kfree_sensitive(new_p);
> -		goto out;
> -	}
> -	if (new_o->pcrlock) {
> -		ret = pcrlock(new_o->pcrlock);
> +	if (options->pcrlock) {
> +		ret = pcrlock(options->pcrlock);
>  		if (ret < 0) {
> -			pr_info("trusted_key: pcrlock failed (%d)\n", ret);
> -			kfree_sensitive(new_p);
> +			pr_info("pcrlock failed (%d)\n", ret);
>  			goto out;
>  		}
>  	}
> -	rcu_assign_keypointer(key, new_p);
> -	call_rcu(&p->rcu, trusted_rcu_free);
>  out:
> -	kfree_sensitive(datablob);
> -	kfree_sensitive(new_o);
> +	kfree_sensitive(options);
>  	return ret;
>  }
>  
> -/*
> - * trusted_read - copy the sealed blob data to userspace in hex.
> - * On success, return to userspace the trusted key datablob size.
> - */
> -static long trusted_read(const struct key *key, char *buffer,
> -			 size_t buflen)
> +static int trusted_tpm_get_random(unsigned char *key, size_t key_len)
>  {
> -	const struct trusted_key_payload *p;
> -	char *bufp;
> -	int i;
> -
> -	p = dereference_key_locked(key);
> -	if (!p)
> -		return -EINVAL;
> -
> -	if (buffer && buflen >= 2 * p->blob_len) {
> -		bufp = buffer;
> -		for (i = 0; i < p->blob_len; i++)
> -			bufp = hex_byte_pack(bufp, p->blob[i]);
> -	}
> -	return 2 * p->blob_len;
> +	return tpm_get_random(chip, key, key_len);
>  }
>  
> -/*
> - * trusted_destroy - clear and free the key's payload
> - */
> -static void trusted_destroy(struct key *key)
> -{
> -	kfree_sensitive(key->payload.data[0]);
> -}
> -
> -struct key_type key_type_trusted = {
> -	.name = "trusted",
> -	.instantiate = trusted_instantiate,
> -	.update = trusted_update,
> -	.destroy = trusted_destroy,
> -	.describe = user_describe,
> -	.read = trusted_read,
> -};
> -
> -EXPORT_SYMBOL_GPL(key_type_trusted);
> -
>  static void trusted_shash_release(void)
>  {
>  	if (hashalg)
> @@ -1196,14 +967,14 @@ static int __init trusted_shash_alloc(void)
>  
>  	hmacalg = crypto_alloc_shash(hmac_alg, 0, 0);
>  	if (IS_ERR(hmacalg)) {
> -		pr_info("trusted_key: could not allocate crypto %s\n",
> +		pr_info("could not allocate crypto %s\n",
>  			hmac_alg);
>  		return PTR_ERR(hmacalg);
>  	}
>  
>  	hashalg = crypto_alloc_shash(hash_alg, 0, 0);
>  	if (IS_ERR(hashalg)) {
> -		pr_info("trusted_key: could not allocate crypto %s\n",
> +		pr_info("could not allocate crypto %s\n",
>  			hash_alg);
>  		ret = PTR_ERR(hashalg);
>  		goto hashalg_fail;
> @@ -1231,16 +1002,13 @@ static int __init init_digests(void)
>  	return 0;
>  }
>  
> -static int __init init_trusted(void)
> +static int trusted_tpm_init(void)
>  {
>  	int ret;
>  
> -	/* encrypted_keys.ko depends on successful load of this module even if
> -	 * TPM is not used.
> -	 */
>  	chip = tpm_default_chip();
>  	if (!chip)
> -		return 0;
> +		return -ENODEV;
>  
>  	ret = init_digests();
>  	if (ret < 0)
> @@ -1261,7 +1029,7 @@ static int __init init_trusted(void)
>  	return ret;
>  }
>  
> -static void __exit cleanup_trusted(void)
> +static void trusted_tpm_exit(void)
>  {
>  	if (chip) {
>  		put_device(&chip->dev);
> @@ -1271,7 +1039,11 @@ static void __exit cleanup_trusted(void)
>  	}
>  }
>  
> -late_initcall(init_trusted);
> -module_exit(cleanup_trusted);
> -
> -MODULE_LICENSE("GPL");
> +struct trusted_key_ops trusted_key_tpm_ops = {
> +	.migratable = 1, /* migratable by default */
> +	.init = trusted_tpm_init,
> +	.seal = trusted_tpm_seal,
> +	.unseal = trusted_tpm_unseal,
> +	.get_random = trusted_tpm_get_random,
> +	.exit = trusted_tpm_exit,
> +};
> -- 
> 2.25.1
> 
>