keys: add new trusted key-type

Define a new kernel key-type called 'trusted'. Trusted keys are random
number symmetric keys, generated and RSA-sealed by the TPM. The TPM
only unseals the keys, if the boot PCRs and other criteria match.
Userspace can only ever see encrypted blobs.

Based on suggestions by Jason Gunthorpe, several new options have been
added to support additional usages.

The new options are:
migratable= designates that the key may/may not ever be updated
(resealed under a new key, new pcrinfo or new auth.)

pcrlock=n extends the designated PCR 'n' with a random value,
so that a key sealed to that PCR may not be unsealed
again until after a reboot.

keyhandle= specifies the sealing/unsealing key handle.

keyauth= specifies the sealing/unsealing key auth.

blobauth= specifies the sealed data auth.

Implementation of a kernel reserved locality for trusted keys will be
investigated for a possible future extension.

Changelog:
- Updated and added examples to Documentation/keys-trusted-encrypted.txt
- Moved generic TPM constants to include/linux/tpm_command.h
(David Howell's suggestion.)
- trusted_defined.c: replaced kzalloc with kmalloc, added pcrlock failure
error handling, added const qualifiers where appropriate.
- moved to late_initcall
- updated from hash to shash (suggestion by David Howells)
- reduced worst stack usage (tpm_seal) from 530 to 312 bytes
- moved documentation to Documentation directory (suggestion by David Howells)
- all the other code cleanups suggested by David Howells
- Add pcrlock CAP_SYS_ADMIN dependency (based on comment by Jason Gunthorpe)
- New options: migratable, pcrlock, keyhandle, keyauth, blobauth (based on
discussions with Jason Gunthorpe)
- Free payload on failure to create key(reported/fixed by Roberto Sassu)
- Updated Kconfig and other descriptions (based on Serge Hallyn's suggestion)
- Replaced kzalloc() with kmalloc() (reported by Serge Hallyn)

Signed-off-by: David Safford <[e-mail]>
Signed-off-by: Mimi Zohar <[e-mail]>
Signed-off-by: James Morris <[e-mail]>

Documentation/keys-trusted-encrypted.txt

···
+			Trusted and Encrypted Keys
+
+Trusted and Encrypted Keys are two new key types added to the existing kernel
+key ring service.  Both of these new types are variable length symmetic 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.
+
+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.
+
+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".
+
+Usage:
+    keyctl add trusted name "new keylen [options]" ring
+    keyctl add trusted name "load hex_blob [pcrlock=pcrnum]" ring
+    keyctl update key "update [options]"
+    keyctl print keyid
+
+    options:
+       keyhandle= ascii hex value of sealing key default 0x40000000 (SRK)
+       keyauth=	  ascii hex auth for sealing key default 0x00...i
+		  (40 ascii zeros)
+       blobauth=  ascii hex auth for sealed data default 0x00...
+		  (40 ascii zeros)
+       blobauth=  ascii hex auth for sealed data default 0x00...
+		  (40 ascii zeros)
+       pcrinfo=	  ascii hex of PCR_INFO or PCR_INFO_LONG (no default)
+       pcrlock=	  pcr number to be extended to "lock" blob
+       migratable= 0|1 indicating permission to reseal to new PCR values,
+                   default 1 (resealing allowed)
+
+"keyctl print" returns an ascii hex copy of the sealed key, which is in standard
+TPM_STORED_DATA format.  The key length for new keys are always in bytes.
+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.
+
+Usage:
+  keyctl add encrypted name "new key-type:master-key-name keylen" ring
+  keyctl add encrypted name "load hex_blob" ring
+  keyctl update keyid "update key-type:master-key-name"
+
+where 'key-type' is either 'trusted' or 'user'.
+
+Examples of trusted and encrypted key usage:
+
+Create and save a trusted key named "kmk" of length 32 bytes:
+
+    $ keyctl add trusted kmk "new 32" @u
+    440502848
+
+    $ keyctl show
+    Session Keyring
+           -3 --alswrv    500   500  keyring: _ses
+     97833714 --alswrv    500    -1   \_ keyring: _uid.500
+    440502848 --alswrv    500   500       \_ trusted: kmk
+
+    $ keyctl print 440502848
+    0101000000000000000001005d01b7e3f4a6be5709930f3b70a743cbb42e0cc95e18e915
+    3f60da455bbf1144ad12e4f92b452f966929f6105fd29ca28e4d4d5a031d068478bacb0b
+    27351119f822911b0a11ba3d3498ba6a32e50dac7f32894dd890eb9ad578e4e292c83722
+    a52e56a097e6a68b3f56f7a52ece0cdccba1eb62cad7d817f6dc58898b3ac15f36026fec
+    d568bd4a706cb60bb37be6d8f1240661199d640b66fb0fe3b079f97f450b9ef9c22c6d5d
+    dd379f0facd1cd020281dfa3c70ba21a3fa6fc2471dc6d13ecf8298b946f65345faa5ef0
+    f1f8fff03ad0acb083725535636addb08d73dedb9832da198081e5deae84bfaf0409c22b
+    e4a8aea2b607ec96931e6f4d4fe563ba
+
+    $ keyctl pipe 440502848 > kmk.blob
+
+Load a trusted key from the saved blob:
+
+    $ keyctl add trusted kmk "load `cat kmk.blob`" @u
+    268728824
+
+    $ keyctl print 268728824
+    0101000000000000000001005d01b7e3f4a6be5709930f3b70a743cbb42e0cc95e18e915
+    3f60da455bbf1144ad12e4f92b452f966929f6105fd29ca28e4d4d5a031d068478bacb0b
+    27351119f822911b0a11ba3d3498ba6a32e50dac7f32894dd890eb9ad578e4e292c83722
+    a52e56a097e6a68b3f56f7a52ece0cdccba1eb62cad7d817f6dc58898b3ac15f36026fec
+    d568bd4a706cb60bb37be6d8f1240661199d640b66fb0fe3b079f97f450b9ef9c22c6d5d
+    dd379f0facd1cd020281dfa3c70ba21a3fa6fc2471dc6d13ecf8298b946f65345faa5ef0
+    f1f8fff03ad0acb083725535636addb08d73dedb9832da198081e5deae84bfaf0409c22b
+    e4a8aea2b607ec96931e6f4d4fe563ba
+
+Reseal a trusted key under new pcr values:
+
+    $ keyctl update 268728824 "update pcrinfo=`cat pcr.blob`"
+    $ keyctl print 268728824
+    010100000000002c0002800093c35a09b70fff26e7a98ae786c641e678ec6ffb6b46d805
+    77c8a6377aed9d3219c6dfec4b23ffe3000001005d37d472ac8a44023fbb3d18583a4f73
+    d3a076c0858f6f1dcaa39ea0f119911ff03f5406df4f7f27f41da8d7194f45c9f4e00f2e
+    df449f266253aa3f52e55c53de147773e00f0f9aca86c64d94c95382265968c354c5eab4
+    9638c5ae99c89de1e0997242edfb0b501744e11ff9762dfd951cffd93227cc513384e7e6
+    e782c29435c7ec2edafaa2f4c1fe6e7a781b59549ff5296371b42133777dcc5b8b971610
+    94bc67ede19e43ddb9dc2baacad374a36feaf0314d700af0a65c164b7082401740e489c9
+    7ef6a24defe4846104209bf0c3eced7fa1a672ed5b125fc9d8cd88b476a658a4434644ef
+    df8ae9a178e9f83ba9f08d10fa47e4226b98b0702f06b3b8
+
+Create and save an encrypted key "evm" using the above trusted key "kmk":
+
+    $ keyctl add encrypted evm "new trusted:kmk 32" @u
+    159771175
+
+    $ keyctl print 159771175
+    trusted:kmk 32 2375725ad57798846a9bbd240de8906f006e66c03af53b1b382dbbc55
+    be2a44616e4959430436dc4f2a7a9659aa60bb4652aeb2120f149ed197c564e024717c64
+    5972dcb82ab2dde83376d82b2e3c09ffc
+
+    $ keyctl pipe 159771175 > evm.blob
+
+Load an encrypted key "evm" from saved blob:
+
+    $ keyctl add encrypted evm "load `cat evm.blob`" @u
+    831684262
+
+    $ keyctl print 831684262
+    trusted:kmk 32 2375725ad57798846a9bbd240de8906f006e66c03af53b1b382dbbc55
+    be2a44616e4959430436dc4f2a7a9659aa60bb4652aeb2120f149ed197c564e024717c64
+    5972dcb82ab2dde83376d82b2e3c09ffc
+
+
+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.  Other uses for trusted and
+encrypted keys, such as for disk and file encryption are anticipated.

include/keys/trusted-type.h

···
+/*
+ * Copyright (C) 2010 IBM Corporation
+ * Author: David Safford <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ */
+
+#ifndef _KEYS_TRUSTED_TYPE_H
+#define _KEYS_TRUSTED_TYPE_H
+
+#include <linux/key.h>
+#include <linux/rcupdate.h>
+
+#define MIN_KEY_SIZE			32
+#define MAX_KEY_SIZE			128
+#define MAX_BLOB_SIZE			320
+
+struct trusted_key_payload {
+	struct rcu_head rcu;
+	unsigned int key_len;
+	unsigned int blob_len;
+	unsigned char migratable;
+	unsigned char key[MAX_KEY_SIZE + 1];
+	unsigned char blob[MAX_BLOB_SIZE];
+};
+
+extern struct key_type key_type_trusted;
+
+#endif /* _KEYS_TRUSTED_TYPE_H */

include/linux/tpm_command.h

···
+#ifndef __LINUX_TPM_COMMAND_H__
+#define __LINUX_TPM_COMMAND_H__
+
+/*
+ * TPM Command constants from specifications at
+ * http://www.trustedcomputinggroup.org
+ */
+
+/* Command TAGS */
+#define TPM_TAG_RQU_COMMAND             193
+#define TPM_TAG_RQU_AUTH1_COMMAND       194
+#define TPM_TAG_RQU_AUTH2_COMMAND       195
+#define TPM_TAG_RSP_COMMAND             196
+#define TPM_TAG_RSP_AUTH1_COMMAND       197
+#define TPM_TAG_RSP_AUTH2_COMMAND       198
+
+/* Command Ordinals */
+#define TPM_ORD_GETRANDOM               70
+#define TPM_ORD_OSAP                    11
+#define TPM_ORD_OIAP                    10
+#define TPM_ORD_SEAL                    23
+#define TPM_ORD_UNSEAL                  24
+
+/* Other constants */
+#define SRKHANDLE                       0x40000000
+#define TPM_NONCE_SIZE                  20
+
+#endif

security/Kconfig

···
 
 	  If you are unsure as to whether this is required, answer N.
 
+config TRUSTED_KEYS
+	tristate "TRUSTED KEYS"
+	depends on KEYS && TCG_TPM
+	select CRYPTO
+	select CRYPTO_HMAC
+	select CRYPTO_SHA1
+	help
+	  This option provides support for creating, sealing, and unsealing
+	  keys in the kernel. Trusted keys are random number symmetric keys,
+	  generated and RSA-sealed by the TPM. The TPM only unseals the keys,
+	  if the boot PCRs and other criteria match.  Userspace will only ever
+	  see encrypted blobs.
+
+	  If you are unsure as to whether this is required, answer N.
+
 config KEYS_DEBUG_PROC_KEYS
 	bool "Enable the /proc/keys file by which keys may be viewed"
 	depends on KEYS

security/keys/Makefile

···
 	request_key_auth.o \
 	user_defined.o
 
+obj-$(CONFIG_TRUSTED_KEYS) += trusted_defined.o
 obj-$(CONFIG_KEYS_COMPAT) += compat.o
 obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_SYSCTL) += sysctl.o

security/keys/trusted_defined.c

···
+/*
+ * Copyright (C) 2010 IBM Corporation
+ *
+ * Author:
+ * David Safford <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * See Documentation/keys-trusted-encrypted.txt
+ */
+
+#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 <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/sha.h>
+#include <linux/capability.h>
+#include <linux/tpm.h>
+#include <linux/tpm_command.h>
+
+#include "trusted_defined.h"
+
+static const char hmac_alg[] = "hmac(sha1)";
+static const char hash_alg[] = "sha1";
+
+struct sdesc {
+	struct shash_desc shash;
+	char ctx[];
+};
+
+static struct crypto_shash *hashalg;
+static struct crypto_shash *hmacalg;
+
+static struct sdesc *init_sdesc(struct crypto_shash *alg)
+{
+	struct sdesc *sdesc;
+	int size;
+
+	size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
+	sdesc = kmalloc(size, GFP_KERNEL);
+	if (!sdesc)
+		return ERR_PTR(-ENOMEM);
+	sdesc->shash.tfm = alg;
+	sdesc->shash.flags = 0x0;
+	return sdesc;
+}
+
+static int TSS_sha1(const unsigned char *data, const unsigned int datalen,
+		    unsigned char *digest)
+{
+	struct sdesc *sdesc;
+	int ret;
+
+	sdesc = init_sdesc(hashalg);
+	if (IS_ERR(sdesc)) {
+		pr_info("trusted_key: can't alloc %s\n", hash_alg);
+		return PTR_ERR(sdesc);
+	}
+
+	ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
+	kfree(sdesc);
+	return ret;
+}
+
+static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
+		       const unsigned int keylen, ...)
+{
+	struct sdesc *sdesc;
+	va_list argp;
+	unsigned int dlen;
+	unsigned char *data;
+	int ret;
+
+	sdesc = init_sdesc(hmacalg);
+	if (IS_ERR(sdesc)) {
+		pr_info("trusted_key: can't alloc %s\n", hmac_alg);
+		return PTR_ERR(sdesc);
+	}
+
+	ret = crypto_shash_setkey(hmacalg, key, keylen);
+	if (ret < 0)
+		goto out;
+	ret = crypto_shash_init(&sdesc->shash);
+	if (ret < 0)
+		goto out;
+
+	va_start(argp, keylen);
+	for (;;) {
+		dlen = va_arg(argp, unsigned int);
+		if (dlen == 0)
+			break;
+		data = va_arg(argp, unsigned char *);
+		if (data == NULL)
+			return -EINVAL;
+		ret = crypto_shash_update(&sdesc->shash, data, dlen);
+		if (ret < 0)
+			goto out;
+	}
+	va_end(argp);
+	ret = crypto_shash_final(&sdesc->shash, digest);
+out:
+	kfree(sdesc);
+	return ret;
+}
+
+/*
+ * calculate authorization info fields to send to TPM
+ */
+static uint32_t TSS_authhmac(unsigned char *digest, const unsigned char *key,
+			     const unsigned int keylen, unsigned char *h1,
+			     unsigned char *h2, unsigned char h3, ...)
+{
+	unsigned char paramdigest[SHA1_DIGEST_SIZE];
+	struct sdesc *sdesc;
+	unsigned int dlen;
+	unsigned char *data;
+	unsigned char c;
+	int ret;
+	va_list argp;
+
+	sdesc = init_sdesc(hashalg);
+	if (IS_ERR(sdesc)) {
+		pr_info("trusted_key: can't alloc %s\n", hash_alg);
+		return PTR_ERR(sdesc);
+	}
+
+	c = h3;
+	ret = crypto_shash_init(&sdesc->shash);
+	if (ret < 0)
+		goto out;
+	va_start(argp, h3);
+	for (;;) {
+		dlen = va_arg(argp, unsigned int);
+		if (dlen == 0)
+			break;
+		data = va_arg(argp, unsigned char *);
+		ret = crypto_shash_update(&sdesc->shash, data, dlen);
+		if (ret < 0)
+			goto out;
+	}
+	va_end(argp);
+	ret = crypto_shash_final(&sdesc->shash, paramdigest);
+	if (!ret)
+		TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE,
+			    paramdigest, TPM_NONCE_SIZE, h1,
+			    TPM_NONCE_SIZE, h2, 1, &c, 0, 0);
+out:
+	kfree(sdesc);
+	return ret;
+}
+
+/*
+ * verify the AUTH1_COMMAND (Seal) result from TPM
+ */
+static uint32_t TSS_checkhmac1(unsigned char *buffer,
+			       const uint32_t command,
+			       const unsigned char *ononce,
+			       const unsigned char *key,
+			       const unsigned int keylen, ...)
+{
+	uint32_t bufsize;
+	uint16_t tag;
+	uint32_t ordinal;
+	uint32_t result;
+	unsigned char *enonce;
+	unsigned char *continueflag;
+	unsigned char *authdata;
+	unsigned char testhmac[SHA1_DIGEST_SIZE];
+	unsigned char paramdigest[SHA1_DIGEST_SIZE];
+	struct sdesc *sdesc;
+	unsigned int dlen;
+	unsigned int dpos;
+	va_list argp;
+	int ret;
+
+	bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
+	tag = LOAD16(buffer, 0);
+	ordinal = command;
+	result = LOAD32N(buffer, TPM_RETURN_OFFSET);
+	if (tag == TPM_TAG_RSP_COMMAND)
+		return 0;
+	if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
+		return -EINVAL;
+	authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
+	continueflag = authdata - 1;
+	enonce = continueflag - TPM_NONCE_SIZE;
+
+	sdesc = init_sdesc(hashalg);
+	if (IS_ERR(sdesc)) {
+		pr_info("trusted_key: can't alloc %s\n", hash_alg);
+		return PTR_ERR(sdesc);
+	}
+	ret = crypto_shash_init(&sdesc->shash);
+	if (ret < 0)
+		goto out;
+	ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
+				  sizeof result);
+	if (ret < 0)
+		goto out;
+	ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
+				  sizeof ordinal);
+	if (ret < 0)
+		goto out;
+	va_start(argp, keylen);
+	for (;;) {
+		dlen = va_arg(argp, unsigned int);
+		if (dlen == 0)
+			break;
+		dpos = va_arg(argp, unsigned int);
+		ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
+		if (ret < 0)
+			goto out;
+	}
+	va_end(argp);
+	ret = crypto_shash_final(&sdesc->shash, paramdigest);
+	if (ret < 0)
+		goto out;
+	ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
+			  TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
+			  1, continueflag, 0, 0);
+	if (ret < 0)
+		goto out;
+	if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
+		ret = -EINVAL;
+out:
+	kfree(sdesc);
+	return ret;
+}
+
+/*
+ * verify the AUTH2_COMMAND (unseal) result from TPM
+ */
+static uint32_t TSS_checkhmac2(unsigned char *buffer,
+			       const uint32_t command,
+			       const unsigned char *ononce,
+			       const unsigned char *key1,
+			       const unsigned int keylen1,
+			       const unsigned char *key2,
+			       const unsigned int keylen2, ...)
+{
+	uint32_t bufsize;
+	uint16_t tag;
+	uint32_t ordinal;
+	uint32_t result;
+	unsigned char *enonce1;
+	unsigned char *continueflag1;
+	unsigned char *authdata1;
+	unsigned char *enonce2;
+	unsigned char *continueflag2;
+	unsigned char *authdata2;
+	unsigned char testhmac1[SHA1_DIGEST_SIZE];
+	unsigned char testhmac2[SHA1_DIGEST_SIZE];
+	unsigned char paramdigest[SHA1_DIGEST_SIZE];
+	struct sdesc *sdesc;
+	unsigned int dlen;
+	unsigned int dpos;
+	va_list argp;
+	int ret;
+
+	bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
+	tag = LOAD16(buffer, 0);
+	ordinal = command;
+	result = LOAD32N(buffer, TPM_RETURN_OFFSET);
+
+	if (tag == TPM_TAG_RSP_COMMAND)
+		return 0;
+	if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
+		return -EINVAL;
+	authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1
+			+ SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE);
+	authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE);
+	continueflag1 = authdata1 - 1;
+	continueflag2 = authdata2 - 1;
+	enonce1 = continueflag1 - TPM_NONCE_SIZE;
+	enonce2 = continueflag2 - TPM_NONCE_SIZE;
+
+	sdesc = init_sdesc(hashalg);
+	if (IS_ERR(sdesc)) {
+		pr_info("trusted_key: can't alloc %s\n", hash_alg);
+		return PTR_ERR(sdesc);
+	}
+	ret = crypto_shash_init(&sdesc->shash);
+	if (ret < 0)
+		goto out;
+	ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
+				  sizeof result);
+	if (ret < 0)
+		goto out;
+	ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
+				  sizeof ordinal);
+	if (ret < 0)
+		goto out;
+
+	va_start(argp, keylen2);
+	for (;;) {
+		dlen = va_arg(argp, unsigned int);
+		if (dlen == 0)
+			break;
+		dpos = va_arg(argp, unsigned int);
+		ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
+		if (ret < 0)
+			goto out;
+	}
+	ret = crypto_shash_final(&sdesc->shash, paramdigest);
+	if (ret < 0)
+		goto out;
+
+	ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE,
+			  paramdigest, TPM_NONCE_SIZE, enonce1,
+			  TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0);
+	if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) {
+		ret = -EINVAL;
+		goto out;
+	}
+	ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE,
+			  paramdigest, TPM_NONCE_SIZE, enonce2,
+			  TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0);
+	if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE))
+		ret = -EINVAL;
+out:
+	kfree(sdesc);
+	return ret;
+}
+
+/*
+ * For key specific tpm requests, we will generate and send our
+ * own TPM command packets using the drivers send function.
+ */
+static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd,
+			    size_t buflen)
+{
+	int rc;
+
+	dump_tpm_buf(cmd);
+	rc = tpm_send(chip_num, cmd, buflen);
+	dump_tpm_buf(cmd);
+	if (rc > 0)
+		/* Can't return positive return codes values to keyctl */
+		rc = -EPERM;
+	return rc;
+}
+
+/*
+ * get a random value from TPM
+ */
+static int tpm_get_random(struct tpm_buf *tb, unsigned char *buf, uint32_t len)
+{
+	int ret;
+
+	INIT_BUF(tb);
+	store16(tb, TPM_TAG_RQU_COMMAND);
+	store32(tb, TPM_GETRANDOM_SIZE);
+	store32(tb, TPM_ORD_GETRANDOM);
+	store32(tb, len);
+	ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, sizeof tb->data);
+	memcpy(buf, tb->data + TPM_GETRANDOM_SIZE, len);
+
+	return ret;
+}
+
+static int my_get_random(unsigned char *buf, int len)
+{
+	struct tpm_buf *tb;
+	int ret;
+
+	tb = kzalloc(sizeof *tb, GFP_KERNEL);
+	if (!tb)
+		return -ENOMEM;
+	ret = tpm_get_random(tb, buf, len);
+
+	kfree(tb);
+	return ret;
+}
+
+/*
+ * Lock a trusted key, by extending a selected PCR.
+ *
+ * Prevents a trusted key that is sealed to PCRs from being accessed.
+ * This uses the tpm driver's extend function.
+ */
+static int pcrlock(const int pcrnum)
+{
+	unsigned char hash[SHA1_DIGEST_SIZE];
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	my_get_random(hash, SHA1_DIGEST_SIZE);
+	return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0;
+}
+
+/*
+ * Create an object specific authorisation protocol (OSAP) session
+ */
+static int osap(struct tpm_buf *tb, struct osapsess *s,
+		const unsigned char *key, const uint16_t type,
+		const uint32_t handle)
+{
+	unsigned char enonce[TPM_NONCE_SIZE];
+	unsigned char ononce[TPM_NONCE_SIZE];
+	int ret;
+
+	ret = tpm_get_random(tb, ononce, TPM_NONCE_SIZE);
+	if (ret < 0)
+		return ret;
+
+	INIT_BUF(tb);
+	store16(tb, TPM_TAG_RQU_COMMAND);
+	store32(tb, TPM_OSAP_SIZE);
+	store32(tb, TPM_ORD_OSAP);
+	store16(tb, type);
+	store32(tb, handle);
+	storebytes(tb, ononce, TPM_NONCE_SIZE);
+
+	ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
+	if (ret < 0)
+		return ret;
+
+	s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
+	memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
+	       TPM_NONCE_SIZE);
+	memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
+				  TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
+	ret = TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
+			  enonce, TPM_NONCE_SIZE, ononce, 0, 0);
+	return ret;
+}
+
+/*
+ * Create an object independent authorisation protocol (oiap) session
+ */
+static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
+{
+	int ret;
+
+	INIT_BUF(tb);
+	store16(tb, TPM_TAG_RQU_COMMAND);
+	store32(tb, TPM_OIAP_SIZE);
+	store32(tb, TPM_ORD_OIAP);
+	ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
+	if (ret < 0)
+		return ret;
+
+	*handle = LOAD32(tb->data, TPM_DATA_OFFSET);
+	memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
+	       TPM_NONCE_SIZE);
+	return ret;
+}
+
+struct tpm_digests {
+	unsigned char encauth[SHA1_DIGEST_SIZE];
+	unsigned char pubauth[SHA1_DIGEST_SIZE];
+	unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
+	unsigned char xorhash[SHA1_DIGEST_SIZE];
+	unsigned char nonceodd[TPM_NONCE_SIZE];
+};
+
+/*
+ * Have the TPM seal(encrypt) the trusted key, possibly based on
+ * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
+ */
+static int tpm_seal(struct tpm_buf *tb, const uint16_t keytype,
+		    const uint32_t keyhandle, const unsigned char *keyauth,
+		    const unsigned char *data, const uint32_t datalen,
+		    unsigned char *blob, uint32_t *bloblen,
+		    const unsigned char *blobauth,
+		    const unsigned char *pcrinfo, const uint32_t pcrinfosize)
+{
+	struct osapsess sess;
+	struct tpm_digests *td;
+	unsigned char cont;
+	uint32_t ordinal;
+	uint32_t pcrsize;
+	uint32_t datsize;
+	int sealinfosize;
+	int encdatasize;
+	int storedsize;
+	int ret;
+	int i;
+
+	/* alloc some work space for all the hashes */
+	td = kmalloc(sizeof *td, GFP_KERNEL);
+	if (!td)
+		return -ENOMEM;
+
+	/* get session for sealing key */
+	ret = osap(tb, &sess, keyauth, keytype, keyhandle);
+	if (ret < 0)
+		return ret;
+	dump_sess(&sess);
+
+	/* calculate encrypted authorization value */
+	memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
+	memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
+	ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
+	if (ret < 0)
+		return ret;
+
+	ret = tpm_get_random(tb, td->nonceodd, TPM_NONCE_SIZE);
+	if (ret < 0)
+		return ret;
+	ordinal = htonl(TPM_ORD_SEAL);
+	datsize = htonl(datalen);
+	pcrsize = htonl(pcrinfosize);
+	cont = 0;
+
+	/* encrypt data authorization key */
+	for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
+		td->encauth[i] = td->xorhash[i] ^ blobauth[i];
+
+	/* calculate authorization HMAC value */
+	if (pcrinfosize == 0) {
+		/* no pcr info specified */
+		TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
+			     sess.enonce, td->nonceodd, cont, sizeof(uint32_t),
+			     &ordinal, SHA1_DIGEST_SIZE, td->encauth,
+			     sizeof(uint32_t), &pcrsize, sizeof(uint32_t),
+			     &datsize, datalen, data, 0, 0);
+	} else {
+		/* pcr info specified */
+		TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
+			     sess.enonce, td->nonceodd, cont, sizeof(uint32_t),
+			     &ordinal, SHA1_DIGEST_SIZE, td->encauth,
+			     sizeof(uint32_t), &pcrsize, pcrinfosize,
+			     pcrinfo, sizeof(uint32_t), &datsize, datalen,
+			     data, 0, 0);
+	}
+
+	/* build and send the TPM request packet */
+	INIT_BUF(tb);
+	store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
+	store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen);
+	store32(tb, TPM_ORD_SEAL);
+	store32(tb, keyhandle);
+	storebytes(tb, td->encauth, SHA1_DIGEST_SIZE);
+	store32(tb, pcrinfosize);
+	storebytes(tb, pcrinfo, pcrinfosize);
+	store32(tb, datalen);
+	storebytes(tb, data, datalen);
+	store32(tb, sess.handle);
+	storebytes(tb, td->nonceodd, TPM_NONCE_SIZE);
+	store8(tb, cont);
+	storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE);
+
+	ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
+	if (ret < 0)
+		return ret;
+
+	/* calculate the size of the returned Blob */
+	sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
+	encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
+			     sizeof(uint32_t) + sealinfosize);
+	storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
+	    sizeof(uint32_t) + encdatasize;
+
+	/* check the HMAC in the response */
+	ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
+			     SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
+			     0);
+
+	/* copy the returned blob to caller */
+	memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
+	*bloblen = storedsize;
+	return ret;
+}
+
+/*
+ * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
+ */
+static int tpm_unseal(struct tpm_buf *tb,
+		      const uint32_t keyhandle, const unsigned char *keyauth,
+		      const unsigned char *blob, const int bloblen,
+		      const unsigned char *blobauth,
+		      unsigned char *data, unsigned int *datalen)
+{
+	unsigned char nonceodd[TPM_NONCE_SIZE];
+	unsigned char enonce1[TPM_NONCE_SIZE];
+	unsigned char enonce2[TPM_NONCE_SIZE];
+	unsigned char authdata1[SHA1_DIGEST_SIZE];
+	unsigned char authdata2[SHA1_DIGEST_SIZE];
+	uint32_t authhandle1 = 0;
+	uint32_t authhandle2 = 0;
+	unsigned char cont = 0;
+	uint32_t ordinal;
+	uint32_t keyhndl;
+	int ret;
+
+	/* sessions for unsealing key and data */
+	ret = oiap(tb, &authhandle1, enonce1);
+	if (ret < 0) {
+		pr_info("trusted_key: oiap failed (%d)\n", ret);
+		return ret;
+	}
+	ret = oiap(tb, &authhandle2, enonce2);
+	if (ret < 0) {
+		pr_info("trusted_key: oiap failed (%d)\n", ret);
+		return ret;
+	}
+
+	ordinal = htonl(TPM_ORD_UNSEAL);
+	keyhndl = htonl(SRKHANDLE);
+	ret = tpm_get_random(tb, nonceodd, TPM_NONCE_SIZE);
+	if (ret < 0) {
+		pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
+		return ret;
+	}
+	TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
+		     enonce1, nonceodd, cont, sizeof(uint32_t),
+		     &ordinal, bloblen, blob, 0, 0);
+	TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
+		     enonce2, nonceodd, cont, sizeof(uint32_t),
+		     &ordinal, bloblen, blob, 0, 0);
+
+	/* build and send TPM request packet */
+	INIT_BUF(tb);
+	store16(tb, TPM_TAG_RQU_AUTH2_COMMAND);
+	store32(tb, TPM_UNSEAL_SIZE + bloblen);
+	store32(tb, TPM_ORD_UNSEAL);
+	store32(tb, keyhandle);
+	storebytes(tb, blob, bloblen);
+	store32(tb, authhandle1);
+	storebytes(tb, nonceodd, TPM_NONCE_SIZE);
+	store8(tb, cont);
+	storebytes(tb, authdata1, SHA1_DIGEST_SIZE);
+	store32(tb, authhandle2);
+	storebytes(tb, nonceodd, TPM_NONCE_SIZE);
+	store8(tb, cont);
+	storebytes(tb, authdata2, SHA1_DIGEST_SIZE);
+
+	ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
+	if (ret < 0) {
+		pr_info("trusted_key: authhmac failed (%d)\n", ret);
+		return ret;
+	}
+
+	*datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
+	ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
+			     keyauth, SHA1_DIGEST_SIZE,
+			     blobauth, SHA1_DIGEST_SIZE,
+			     sizeof(uint32_t), TPM_DATA_OFFSET,
+			     *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
+			     0);
+	if (ret < 0)
+		pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret);
+	memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
+	return ret;
+}
+
+/*
+ * Have the TPM seal(encrypt) the symmetric key
+ */
+static int key_seal(struct trusted_key_payload *p,
+		    struct trusted_key_options *o)
+{
+	struct tpm_buf *tb;
+	int ret;
+
+	tb = kzalloc(sizeof *tb, GFP_KERNEL);
+	if (!tb)
+		return -ENOMEM;
+
+	/* include migratable flag at end of sealed key */
+	p->key[p->key_len] = p->migratable;
+
+	ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth,
+		       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);
+
+	kfree(tb);
+	return ret;
+}
+
+/*
+ * Have the TPM unseal(decrypt) the symmetric key
+ */
+static int key_unseal(struct trusted_key_payload *p,
+		      struct trusted_key_options *o)
+{
+	struct tpm_buf *tb;
+	int ret;
+
+	tb = kzalloc(sizeof *tb, GFP_KERNEL);
+	if (!tb)
+		return -ENOMEM;
+
+	ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
+			 o->blobauth, p->key, &p->key_len);
+	/* pull migratable flag out of sealed key */
+	p->migratable = p->key[--p->key_len];
+
+	if (ret < 0)
+		pr_info("trusted_key: srkunseal failed (%d)\n", ret);
+
+	kfree(tb);
+	return ret;
+}
+
+enum {
+	Opt_err = -1,
+	Opt_new, Opt_load, Opt_update,
+	Opt_keyhandle, Opt_keyauth, Opt_blobauth,
+	Opt_pcrinfo, Opt_pcrlock, Opt_migratable
+};
+
+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"},
+	{Opt_pcrinfo, "pcrinfo=%s"},
+	{Opt_pcrlock, "pcrlock=%s"},
+	{Opt_migratable, "migratable=%s"},
+	{Opt_err, NULL}
+};
+
+/* can have zero or more token= options */
+static int getoptions(char *c, struct trusted_key_payload *pay,
+		      struct trusted_key_options *opt)
+{
+	substring_t args[MAX_OPT_ARGS];
+	char *p = c;
+	int token;
+	int res;
+	unsigned long handle;
+	unsigned long lock;
+
+	while ((p = strsep(&c, " \t"))) {
+		if (*p == '\0' || *p == ' ' || *p == '\t')
+			continue;
+		token = match_token(p, key_tokens, args);
+
+		switch (token) {
+		case Opt_pcrinfo:
+			opt->pcrinfo_len = strlen(args[0].from) / 2;
+			if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
+				return -EINVAL;
+			hex2bin(opt->pcrinfo, args[0].from, opt->pcrinfo_len);
+			break;
+		case Opt_keyhandle:
+			res = strict_strtoul(args[0].from, 16, &handle);
+			if (res < 0)
+				return -EINVAL;
+			opt->keytype = SEAL_keytype;
+			opt->keyhandle = handle;
+			break;
+		case Opt_keyauth:
+			if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
+				return -EINVAL;
+			hex2bin(opt->keyauth, args[0].from, SHA1_DIGEST_SIZE);
+			break;
+		case Opt_blobauth:
+			if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
+				return -EINVAL;
+			hex2bin(opt->blobauth, args[0].from, SHA1_DIGEST_SIZE);
+			break;
+		case Opt_migratable:
+			if (*args[0].from == '0')
+				pay->migratable = 0;
+			else
+				return -EINVAL;
+			break;
+		case Opt_pcrlock:
+			res = strict_strtoul(args[0].from, 10, &lock);
+			if (res < 0)
+				return -EINVAL;
+			opt->pcrlock = lock;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+	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 = strict_strtol(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;
+		hex2bin(p->blob, c, p->blob_len);
+		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;
+
+	options = kzalloc(sizeof *options, GFP_KERNEL);
+	if (!options)
+		return options;
+
+	/* set any non-zero defaults */
+	options->keytype = SRK_keytype;
+	options->keyhandle = SRKHANDLE;
+	return options;
+}
+
+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);
+
+	/* migratable by default */
+	p->migratable = 1;
+	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, const void *data,
+			       const size_t datalen)
+{
+	struct trusted_key_payload *payload = NULL;
+	struct trusted_key_options *options = NULL;
+	char *datablob;
+	int ret = 0;
+	int key_cmd;
+
+	if (datalen <= 0 || datalen > 32767 || !data)
+		return -EINVAL;
+
+	datablob = kmalloc(datalen + 1, GFP_KERNEL);
+	if (!datablob)
+		return -ENOMEM;
+	memcpy(datablob, 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;
+	}
+
+	key_cmd = datablob_parse(datablob, payload, options);
+	if (key_cmd < 0) {
+		ret = key_cmd;
+		goto out;
+	}
+
+	dump_payload(payload);
+	dump_options(options);
+
+	switch (key_cmd) {
+	case Opt_load:
+		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:
+		ret = my_get_random(payload->key, payload->key_len);
+		if (ret < 0) {
+			pr_info("trusted_key: key_create failed (%d)\n", ret);
+			goto out;
+		}
+		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(datablob);
+	kfree(options);
+	if (!ret)
+		rcu_assign_pointer(key->payload.data, payload);
+	else
+		kfree(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);
+	memset(p->key, 0, p->key_len);
+	kfree(p);
+}
+
+/*
+ * trusted_update - reseal an existing key with new PCR values
+ */
+static int trusted_update(struct key *key, const void *data,
+			  const size_t datalen)
+{
+	struct trusted_key_payload *p = key->payload.data;
+	struct trusted_key_payload *new_p;
+	struct trusted_key_options *new_o;
+	char *datablob;
+	int ret = 0;
+
+	if (!p->migratable)
+		return -EPERM;
+	if (datalen <= 0 || datalen > 32767 || !data)
+		return -EINVAL;
+
+	datablob = kmalloc(datalen + 1, GFP_KERNEL);
+	if (!datablob)
+		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, data, datalen);
+	datablob[datalen] = '\0';
+	ret = datablob_parse(datablob, new_p, new_o);
+	if (ret != Opt_update) {
+		ret = -EINVAL;
+		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 = key_seal(new_p, new_o);
+	if (ret < 0) {
+		pr_info("trusted_key: key_seal failed (%d)\n", ret);
+		kfree(new_p);
+		goto out;
+	}
+	if (new_o->pcrlock) {
+		ret = pcrlock(new_o->pcrlock);
+		if (ret < 0) {
+			pr_info("trusted_key: pcrlock failed (%d)\n", ret);
+			kfree(new_p);
+			goto out;
+		}
+	}
+	rcu_assign_pointer(key->payload.data, new_p);
+	call_rcu(&p->rcu, trusted_rcu_free);
+out:
+	kfree(datablob);
+	kfree(new_o);
+	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 __user *buffer,
+			 size_t buflen)
+{
+	struct trusted_key_payload *p;
+	char *ascii_buf;
+	char *bufp;
+	int i;
+
+	p = rcu_dereference_protected(key->payload.data,
+			rwsem_is_locked(&((struct key *)key)->sem));
+	if (!p)
+		return -EINVAL;
+	if (!buffer || buflen <= 0)
+		return 2 * p->blob_len;
+	ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL);
+	if (!ascii_buf)
+		return -ENOMEM;
+
+	bufp = ascii_buf;
+	for (i = 0; i < p->blob_len; i++)
+		bufp = pack_hex_byte(bufp, p->blob[i]);
+	if ((copy_to_user(buffer, ascii_buf, 2 * p->blob_len)) != 0) {
+		kfree(ascii_buf);
+		return -EFAULT;
+	}
+	kfree(ascii_buf);
+	return 2 * p->blob_len;
+}
+
+/*
+ * trusted_destroy - before freeing the key, clear the decrypted data
+ */
+static void trusted_destroy(struct key *key)
+{
+	struct trusted_key_payload *p = key->payload.data;
+
+	if (!p)
+		return;
+	memset(p->key, 0, p->key_len);
+	kfree(key->payload.data);
+}
+
+struct key_type key_type_trusted = {
+	.name = "trusted",
+	.instantiate = trusted_instantiate,
+	.update = trusted_update,
+	.match = user_match,
+	.destroy = trusted_destroy,
+	.describe = user_describe,
+	.read = trusted_read,
+};
+
+EXPORT_SYMBOL_GPL(key_type_trusted);
+
+static void trusted_shash_release(void)
+{
+	if (hashalg)
+		crypto_free_shash(hashalg);
+	if (hmacalg)
+		crypto_free_shash(hmacalg);
+}
+
+static int __init trusted_shash_alloc(void)
+{
+	int ret;
+
+	hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(hmacalg)) {
+		pr_info("trusted_key: could not allocate crypto %s\n",
+			hmac_alg);
+		return PTR_ERR(hmacalg);
+	}
+
+	hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(hashalg)) {
+		pr_info("trusted_key: could not allocate crypto %s\n",
+			hash_alg);
+		ret = PTR_ERR(hashalg);
+		goto hashalg_fail;
+	}
+
+	return 0;
+
+hashalg_fail:
+	crypto_free_shash(hmacalg);
+	return ret;
+}
+
+static int __init init_trusted(void)
+{
+	int ret;
+
+	ret = trusted_shash_alloc();
+	if (ret < 0)
+		return ret;
+	ret = register_key_type(&key_type_trusted);
+	if (ret < 0)
+		trusted_shash_release();
+	return ret;
+}
+
+static void __exit cleanup_trusted(void)
+{
+	trusted_shash_release();
+	unregister_key_type(&key_type_trusted);
+}
+
+late_initcall(init_trusted);
+module_exit(cleanup_trusted);
+
+MODULE_LICENSE("GPL");

security/keys/trusted_defined.h

···
+#ifndef __TRUSTED_KEY_H
+#define __TRUSTED_KEY_H
+
+/* implementation specific TPM constants */
+#define MAX_PCRINFO_SIZE		64
+#define MAX_BUF_SIZE			512
+#define TPM_GETRANDOM_SIZE		14
+#define TPM_OSAP_SIZE			36
+#define TPM_OIAP_SIZE			10
+#define TPM_SEAL_SIZE			87
+#define TPM_UNSEAL_SIZE			104
+#define TPM_SIZE_OFFSET			2
+#define TPM_RETURN_OFFSET		6
+#define TPM_DATA_OFFSET			10
+
+#define LOAD32(buffer, offset)	(ntohl(*(uint32_t *)&buffer[offset]))
+#define LOAD32N(buffer, offset)	(*(uint32_t *)&buffer[offset])
+#define LOAD16(buffer, offset)	(ntohs(*(uint16_t *)&buffer[offset]))
+
+struct tpm_buf {
+	int len;
+	unsigned char data[MAX_BUF_SIZE];
+};
+
+#define INIT_BUF(tb) (tb->len = 0)
+
+struct osapsess {
+	uint32_t handle;
+	unsigned char secret[SHA1_DIGEST_SIZE];
+	unsigned char enonce[TPM_NONCE_SIZE];
+};
+
+/* discrete values, but have to store in uint16_t for TPM use */
+enum {
+	SEAL_keytype = 1,
+	SRK_keytype = 4
+};
+
+struct trusted_key_options {
+	uint16_t keytype;
+	uint32_t keyhandle;
+	unsigned char keyauth[SHA1_DIGEST_SIZE];
+	unsigned char blobauth[SHA1_DIGEST_SIZE];
+	uint32_t pcrinfo_len;
+	unsigned char pcrinfo[MAX_PCRINFO_SIZE];
+	int pcrlock;
+};
+
+#define TPM_DEBUG 0
+
+#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);
+	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");
+	print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE,
+		       16, 1, &s->secret, SHA1_DIGEST_SIZE, 0);
+	pr_info("trusted-key: enonce:\n");
+	print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE,
+		       16, 1, &s->enonce, SHA1_DIGEST_SIZE, 0);
+}
+
+static inline void dump_tpm_buf(unsigned char *buf)
+{
+	int len;
+
+	pr_info("\ntrusted-key: tpm buffer\n");
+	len = LOAD32(buf, TPM_SIZE_OFFSET);
+	print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, 16, 1, buf, len, 0);
+}
+#else
+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)
+{
+}
+
+static inline void dump_tpm_buf(unsigned char *buf)
+{
+}
+#endif
+
+static inline void store8(struct tpm_buf *buf, const unsigned char value)
+{
+	buf->data[buf->len++] = value;
+}
+
+static inline void store16(struct tpm_buf *buf, const uint16_t value)
+{
+	*(uint16_t *) & buf->data[buf->len] = htons(value);
+	buf->len += sizeof value;
+}
+
+static inline void store32(struct tpm_buf *buf, const uint32_t value)
+{
+	*(uint32_t *) & buf->data[buf->len] = htonl(value);
+	buf->len += sizeof value;
+}
+
+static inline void storebytes(struct tpm_buf *buf, const unsigned char *in,
+			      const int len)
+{
+	memcpy(buf->data + buf->len, in, len);
+	buf->len += len;
+}
+#endif