Commit 903be6bb authored by Denis Kenzior's avatar Denis Kenzior Committed by James Morris
Browse files

KEYS: asym_tpm: add skeleton for asym_tpm [ver #2] 



This patch adds the basic skeleton for the asym_tpm asymmetric key
subtype.

Signed-off-by: default avatarDenis Kenzior <denkenz@gmail.com>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Tested-by: default avatarMarcel Holtmann <marcel@holtmann.org>
Reviewed-by: default avatarMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: default avatarJames Morris <james.morris@microsoft.com>
parent b3a8c8a5

crypto/asymmetric_keys/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -21,6 +21,17 @@ config ASYMMETRIC_PUBLIC_KEY_SUBTYPE 
	  appropriate hash algorithms (such as SHA-1) must be available.

	  ENOPKG will be reported if the requisite algorithm is unavailable.



config ASYMMETRIC_TPM_KEY_SUBTYPE

	tristate "Asymmetric TPM backed private key subtype"

	depends on TCG_TPM

	select CRYPTO_HMAC

	select CRYPTO_SHA1

	select CRYPTO_HASH_INFO

	help

	  This option provides support for TPM backed private key type handling.

	  Operations such as sign, verify, encrypt, decrypt are performed by

	  the TPM after the private key is loaded.



config X509_CERTIFICATE_PARSER

	tristate "X.509 certificate parser"

	depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE

crypto/asymmetric_keys/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ asymmetric_keys-y := \ 
	signature.o



obj-$(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE) += public_key.o

obj-$(CONFIG_ASYMMETRIC_TPM_KEY_SUBTYPE) += asym_tpm.o



#

# X.509 Certificate handling

crypto/asymmetric_keys/asym_tpm.c

0 → 100644
+90 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#define pr_fmt(fmt) "ASYM-TPM: "fmt

#include <linux/slab.h>

#include <linux/module.h>

#include <linux/export.h>

#include <linux/kernel.h>

#include <linux/seq_file.h>

#include <linux/scatterlist.h>

#include <linux/tpm.h>

#include <keys/asymmetric-subtype.h>

#include <crypto/asym_tpm_subtype.h>



/*

 * Provide a part of a description of the key for /proc/keys.

 */

static void asym_tpm_describe(const struct key *asymmetric_key,

			      struct seq_file *m)

{

	struct tpm_key *tk = asymmetric_key->payload.data[asym_crypto];



	if (!tk)

		return;



	seq_printf(m, "TPM1.2/Blob");

}



static void asym_tpm_destroy(void *payload0, void *payload3)

{

	struct tpm_key *tk = payload0;



	if (!tk)

		return;



	kfree(tk->blob);

	tk->blob_len = 0;



	kfree(tk);

}



/* Given the blob, parse it and load it into the TPM */

struct tpm_key *tpm_key_create(const void *blob, uint32_t blob_len)

{

	int r;

	struct tpm_key *tk;



	r = tpm_is_tpm2(NULL);

	if (r < 0)

		goto error;



	/* We don't support TPM2 yet */

	if (r > 0) {

		r = -ENODEV;

		goto error;

	}



	r = -ENOMEM;

	tk = kzalloc(sizeof(struct tpm_key), GFP_KERNEL);

	if (!tk)

		goto error;



	tk->blob = kmemdup(blob, blob_len, GFP_KERNEL);

	if (!tk->blob)

		goto error_memdup;



	tk->blob_len = blob_len;



	return tk;



error_memdup:

	kfree(tk);

error:

	return ERR_PTR(r);

}

EXPORT_SYMBOL_GPL(tpm_key_create);



/*

 * TPM-based asymmetric key subtype

 */

struct asymmetric_key_subtype asym_tpm_subtype = {

	.owner			= THIS_MODULE,

	.name			= "asym_tpm",

	.name_len		= sizeof("asym_tpm") - 1,

	.describe		= asym_tpm_describe,

	.destroy		= asym_tpm_destroy,

};

EXPORT_SYMBOL_GPL(asym_tpm_subtype);



MODULE_DESCRIPTION("TPM based asymmetric key subtype");

MODULE_AUTHOR("Intel Corporation");

MODULE_LICENSE("GPL v2");

include/crypto/asym_tpm_subtype.h

0 → 100644
+16 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#ifndef _LINUX_ASYM_TPM_SUBTYPE_H

#define _LINUX_ASYM_TPM_SUBTYPE_H



#include <linux/keyctl.h>



struct tpm_key {

	void *blob;

	u32 blob_len;

};



struct tpm_key *tpm_key_create(const void *blob, uint32_t blob_len);



extern struct asymmetric_key_subtype asym_tpm_subtype;



#endif /* _LINUX_ASYM_TPM_SUBTYPE_H */