Merge tag 'tpmdd-next-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd

			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

key ring service.  Both of these new types are variable length symmetric keys,

and in both cases all keys are created in the kernel, and user space sees,

stores, and loads only encrypted blobs.  Trusted Keys require the availability

of a Trusted Platform Module (TPM) chip for greater security, while Encrypted

Keys can be used on any system.  All user level blobs, are displayed and loaded

in hex ascii for convenience, and are integrity verified.

of a Trust Source for greater security, while Encrypted Keys can be used on any

system. All user level blobs, are displayed and loaded in hex ASCII for

convenience, and are integrity verified.

Trusted Keys use a TPM both to generate and to seal the keys.  Keys are sealed

under a 2048 bit RSA key in the TPM, and optionally sealed to specified PCR

(integrity measurement) values, and only unsealed by the TPM, if PCRs and blob

integrity verifications match.  A loaded Trusted Key can be updated with new

(future) PCR values, so keys are easily migrated to new pcr values, such as

when the kernel and initramfs are updated.  The same key can have many saved

blobs under different PCR values, so multiple boots are easily supported.

TPM 1.2

-------

Trust Source

============

By default, trusted keys are sealed under the SRK, which has the default

authorization value (20 zeros).  This can be set at takeownership time with the

trouser's utility: "tpm_takeownership -u -z".

A trust source provides the source of security for Trusted Keys.  This

section lists currently supported trust sources, along with their security

considerations.  Whether or not a trust source is sufficiently safe depends

on the strength and correctness of its implementation, as well as the threat

environment for a specific use case.  Since the kernel doesn't know what the

environment is, and there is no metric of trust, it is dependent on the

consumer of the Trusted Keys to determine if the trust source is sufficiently

safe.

TPM 2.0

-------

  *  Root of trust for storage

The user must first create a storage key and make it persistent, so the key is

available after reboot. This can be done using the following commands.

     (1) TPM (Trusted Platform Module: hardware device)

         Rooted to Storage Root Key (SRK) which never leaves the TPM that

         provides crypto operation to establish root of trust for storage.

     (2) TEE (Trusted Execution Environment: OP-TEE based on Arm TrustZone)

         Rooted to Hardware Unique Key (HUK) which is generally burnt in on-chip

         fuses and is accessible to TEE only.

  *  Execution isolation

     (1) TPM

         Fixed set of operations running in isolated execution environment.

     (2) TEE

         Customizable set of operations running in isolated execution

         environment verified via Secure/Trusted boot process.

  * Optional binding to platform integrity state

     (1) TPM

         Keys can be optionally sealed to specified PCR (integrity measurement)

         values, and only unsealed by the TPM, if PCRs and blob integrity

         verifications match. A loaded Trusted Key can be updated with new

         (future) PCR values, so keys are easily migrated to new PCR values,

         such as when the kernel and initramfs are updated. The same key can

         have many saved blobs under different PCR values, so multiple boots are

         easily supported.

     (2) TEE

         Relies on Secure/Trusted boot process for platform integrity. It can

         be extended with TEE based measured boot process.

  *  Interfaces and APIs

     (1) TPM

         TPMs have well-documented, standardized interfaces and APIs.

     (2) TEE

         TEEs have well-documented, standardized client interface and APIs. For

         more details refer to ``Documentation/staging/tee.rst``.

  *  Threat model

     The strength and appropriateness of a particular TPM or TEE for a given

     purpose must be assessed when using them to protect security-relevant data.

Key Generation

==============

Trusted Keys

------------

New keys are created from random numbers generated in the trust source. They

are encrypted/decrypted using a child key in the storage key hierarchy.

Encryption and decryption of the child key must be protected by a strong

access control policy within the trust source.

  *  TPM (hardware device) based RNG

     Strength of random numbers may vary from one device manufacturer to

     another.

  *  TEE (OP-TEE based on Arm TrustZone) based RNG

     RNG is customizable as per platform needs. It can either be direct output

     from platform specific hardware RNG or a software based Fortuna CSPRNG

     which can be seeded via multiple entropy sources.

Encrypted Keys

--------------

Encrypted keys do not depend on a trust source, and are faster, as they use AES

for encryption/decryption. New keys are created from kernel-generated random

numbers, and are encrypted/decrypted using a specified ‘master’ key. The

‘master’ key can either be a trusted-key or user-key type. The main disadvantage

of encrypted keys is that if they are not rooted in a trusted key, they are only

as secure as the user key encrypting them. The master user key should therefore

be loaded in as secure a way as possible, preferably early in boot.

Usage

=====

Trusted Keys usage: TPM

-----------------------

TPM 1.2: By default, trusted keys are sealed under the SRK, which has the

default authorization value (20 bytes of 0s).  This can be set at takeownership

time with the TrouSerS utility: "tpm_takeownership -u -z".

TPM 2.0: The user must first create a storage key and make it persistent, so the

key is available after reboot. This can be done using the following commands.

With the IBM TSS 2 stack::

Trusted Keys can be 32 - 128 bytes (256 - 1024 bits), the upper limit is to fit

within the 2048 bit SRK (RSA) keylength, with all necessary structure/padding.

Encrypted keys do not depend on a TPM, and are faster, as they use AES for

encryption/decryption.  New keys are created from kernel generated random

numbers, and are encrypted/decrypted using a specified 'master' key.  The

'master' key can either be a trusted-key or user-key type.  The main

disadvantage of encrypted keys is that if they are not rooted in a trusted key,

they are only as secure as the user key encrypting them.  The master user key

should therefore be loaded in as secure a way as possible, preferably early in

boot.

Trusted Keys usage: TEE

-----------------------

Usage::

    keyctl add trusted name "new keylen" ring

    keyctl add trusted name "load hex_blob" ring

    keyctl print keyid

"keyctl print" returns an ASCII hex copy of the sealed key, which is in format

specific to TEE device implementation.  The key length for new keys is always

in bytes. Trusted Keys can be 32 - 128 bytes (256 - 1024 bits).

Encrypted Keys usage

--------------------

The decrypted portion of encrypted keys can contain either a simple symmetric

key or a more complex structure. The format of the more complex structure is

	format:= 'default | ecryptfs | enc32'

	key-type:= 'trusted' | 'user'

Examples of trusted and encrypted key usage:

Examples of trusted and encrypted key usage

-------------------------------------------

Create and save a trusted key named "kmk" of length 32 bytes.

    f1f8fff03ad0acb083725535636addb08d73dedb9832da198081e5deae84bfaf0409c22b

    e4a8aea2b607ec96931e6f4d4fe563ba

Reseal a trusted key under new pcr values::

Reseal (TPM specific) a trusted key under new PCR values::

    $ keyctl update 268728824 "update pcrinfo=`cat pcr.blob`"

    $ keyctl print 268728824

    7ef6a24defe4846104209bf0c3eced7fa1a672ed5b125fc9d8cd88b476a658a4434644ef

    df8ae9a178e9f83ba9f08d10fa47e4226b98b0702f06b3b8

The initial consumer of trusted keys is EVM, which at boot time needs a high

quality symmetric key for HMAC protection of file metadata. The use of a

trusted key provides strong guarantees that the EVM key has not been

compromised by a user level problem, and when sealed to specific boot PCR

values, protects against boot and offline attacks.  Create and save an

compromised by a user level problem, and when sealed to a platform integrity

state, protects against boot and offline attacks. Create and save an

encrypted key "evm" using the above trusted key "kmk":

option 1: omitting 'format'::

Another new format 'enc32' has been defined in order to support encrypted keys

with payload size of 32 bytes. This will initially be used for nvdimm security

but may expand to other usages that require 32 bytes payload.

TPM 2.0 ASN.1 Key Format

------------------------

The TPM 2.0 ASN.1 key format is designed to be easily recognisable,

even in binary form (fixing a problem we had with the TPM 1.2 ASN.1

format) and to be extensible for additions like importable keys and

policy::

    TPMKey ::= SEQUENCE {

        type		OBJECT IDENTIFIER

        emptyAuth	[0] EXPLICIT BOOLEAN OPTIONAL

        parent		INTEGER

        pubkey		OCTET STRING

        privkey		OCTET STRING

    }

type is what distinguishes the key even in binary form since the OID

is provided by the TCG to be unique and thus forms a recognizable

binary pattern at offset 3 in the key.  The OIDs currently made

available are::

    2.23.133.10.1.3 TPM Loadable key.  This is an asymmetric key (Usually

                    RSA2048 or Elliptic Curve) which can be imported by a

                    TPM2_Load() operation.

    2.23.133.10.1.4 TPM Importable Key.  This is an asymmetric key (Usually

                    RSA2048 or Elliptic Curve) which can be imported by a

                    TPM2_Import() operation.

    2.23.133.10.1.5 TPM Sealed Data.  This is a set of data (up to 128

                    bytes) which is sealed by the TPM.  It usually

                    represents a symmetric key and must be unsealed before

                    use.

The trusted key code only uses the TPM Sealed Data OID.

emptyAuth is true if the key has well known authorization "".  If it

is false or not present, the key requires an explicit authorization

phrase.  This is used by most user space consumers to decide whether

to prompt for a password.

parent represents the parent key handle, either in the 0x81 MSO space,

like 0x81000001 for the RSA primary storage key.  Userspace programmes

also support specifying the primary handle in the 0x40 MSO space.  If

this happens the Elliptic Curve variant of the primary key using the

TCG defined template will be generated on the fly into a volatile

object and used as the parent.  The current kernel code only supports

the 0x81 MSO form.

pubkey is the binary representation of TPM2B_PRIVATE excluding the

initial TPM2B header, which can be reconstructed from the ASN.1 octet

string length.

privkey is the binary representation of TPM2B_PUBLIC excluding the

initial TPM2B header which can be reconstructed from the ASN.1 octed

string length.

F:	include/keys/trusted_tpm.h

F:	security/keys/trusted-keys/

KEYS-TRUSTED-TEE

M:	Sumit Garg <sumit.garg@linaro.org>

L:	linux-integrity@vger.kernel.org

L:	keyrings@vger.kernel.org

S:	Supported

F:	include/keys/trusted_tee.h

F:	security/keys/trusted-keys/trusted_tee.c

KEYS/KEYRINGS

M:	David Howells <dhowells@redhat.com>

M:	Jarkko Sakkinen <jarkko@kernel.org>

	};

};

/* Check that the given log is indeed a TPM2 log. */

static bool tpm_is_tpm2_log(void *bios_event_log, u64 len)

{

	struct tcg_efi_specid_event_head *efispecid;

	struct tcg_pcr_event *event_header;

	int n;

	if (len < sizeof(*event_header))

		return false;

	len -= sizeof(*event_header);

	event_header = bios_event_log;

	if (len < sizeof(*efispecid))

		return false;

	efispecid = (struct tcg_efi_specid_event_head *)event_header->event;

	n = memcmp(efispecid->signature, TCG_SPECID_SIG,

		   sizeof(TCG_SPECID_SIG));

	return n == 0;

}

/* read binary bios log */

int tpm_read_log_acpi(struct tpm_chip *chip)

{

	struct acpi_table_tpm2 *tbl;

	struct acpi_tpm2_phy *tpm2_phy;

	int format;

	int ret;

	log = &chip->log;

	log->bios_event_log_end = log->bios_event_log + len;

	ret = -EIO;

	virt = acpi_os_map_iomem(start, len);

	if (!virt)

		goto err;

	memcpy_fromio(log->bios_event_log, virt, len);

	acpi_os_unmap_iomem(virt, len);

	if (chip->flags & TPM_CHIP_FLAG_TPM2 &&

	    !tpm_is_tpm2_log(log->bios_event_log, len)) {

		/* try EFI log next */

		ret = -ENODEV;

		goto err;

	}

	return format;

err:

	kfree(log->bios_event_log);

	log->bios_event_log = NULL;

	return -EIO;

	return ret;

}

	int log_version;

	int rc = 0;

	if (chip->flags & TPM_CHIP_FLAG_VIRTUAL)

		return;

	rc = tpm_read_log(chip);

	if (rc < 0)

		return;