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Commit d00a1c72f7f4661212299e6cb132dfa58030bcdb

Authored by Mimi Zohar
Committed by James Morris
1 parent c749ba912e
Exists in master and in 20 other branches dlt-processor-sdk-linux-03.00.00.04, newt-ti-linux-3.12.y, processor-sdk-linux-01.00.00, processor-sdk-linux-02.00.01, smarc-ti-linux-3.12.10, smarc-ti-linux-3.12.y, smarc-ti-linux-3.14.y, smarc-ti-linux-3.15.y, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04, ti-linux-3.12.y, ti-linux-3.14.y, ti-linux-3.15.y, ti-lsk-linux-4.1.y

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 <safford@watson.ibm.com>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

Showing 7 changed files with 1505 additions and 0 deletions Side-by-side Diff

Documentation/keys-trusted-encrypted.txt
Diff comments   View file @ d00a1c7
  1 + Trusted and Encrypted Keys
  2 +
  3 +Trusted and Encrypted Keys are two new key types added to the existing kernel
  4 +key ring service. Both of these new types are variable length symmetic keys,
  5 +and in both cases all keys are created in the kernel, and user space sees,
  6 +stores, and loads only encrypted blobs. Trusted Keys require the availability
  7 +of a Trusted Platform Module (TPM) chip for greater security, while Encrypted
  8 +Keys can be used on any system. All user level blobs, are displayed and loaded
  9 +in hex ascii for convenience, and are integrity verified.
  10 +
  11 +Trusted Keys use a TPM both to generate and to seal the keys. Keys are sealed
  12 +under a 2048 bit RSA key in the TPM, and optionally sealed to specified PCR
  13 +(integrity measurement) values, and only unsealed by the TPM, if PCRs and blob
  14 +integrity verifications match. A loaded Trusted Key can be updated with new
  15 +(future) PCR values, so keys are easily migrated to new pcr values, such as
  16 +when the kernel and initramfs are updated. The same key can have many saved
  17 +blobs under different PCR values, so multiple boots are easily supported.
  18 +
  19 +By default, trusted keys are sealed under the SRK, which has the default
  20 +authorization value (20 zeros). This can be set at takeownership time with the
  21 +trouser's utility: "tpm_takeownership -u -z".
  22 +
  23 +Usage:
  24 + keyctl add trusted name "new keylen [options]" ring
  25 + keyctl add trusted name "load hex_blob [pcrlock=pcrnum]" ring
  26 + keyctl update key "update [options]"
  27 + keyctl print keyid
  28 +
  29 + options:
  30 + keyhandle= ascii hex value of sealing key default 0x40000000 (SRK)
  31 + keyauth= ascii hex auth for sealing key default 0x00...i
  32 + (40 ascii zeros)
  33 + blobauth= ascii hex auth for sealed data default 0x00...
  34 + (40 ascii zeros)
  35 + blobauth= ascii hex auth for sealed data default 0x00...
  36 + (40 ascii zeros)
  37 + pcrinfo= ascii hex of PCR_INFO or PCR_INFO_LONG (no default)
  38 + pcrlock= pcr number to be extended to "lock" blob
  39 + migratable= 0|1 indicating permission to reseal to new PCR values,
  40 + default 1 (resealing allowed)
  41 +
  42 +"keyctl print" returns an ascii hex copy of the sealed key, which is in standard
  43 +TPM_STORED_DATA format. The key length for new keys are always in bytes.
  44 +Trusted Keys can be 32 - 128 bytes (256 - 1024 bits), the upper limit is to fit
  45 +within the 2048 bit SRK (RSA) keylength, with all necessary structure/padding.
  46 +
  47 +Encrypted keys do not depend on a TPM, and are faster, as they use AES for
  48 +encryption/decryption. New keys are created from kernel generated random
  49 +numbers, and are encrypted/decrypted using a specified 'master' key. The
  50 +'master' key can either be a trusted-key or user-key type. The main
  51 +disadvantage of encrypted keys is that if they are not rooted in a trusted key,
  52 +they are only as secure as the user key encrypting them. The master user key
  53 +should therefore be loaded in as secure a way as possible, preferably early in
  54 +boot.
  55 +
  56 +Usage:
  57 + keyctl add encrypted name "new key-type:master-key-name keylen" ring
  58 + keyctl add encrypted name "load hex_blob" ring
  59 + keyctl update keyid "update key-type:master-key-name"
  60 +
  61 +where 'key-type' is either 'trusted' or 'user'.
  62 +
  63 +Examples of trusted and encrypted key usage:
  64 +
  65 +Create and save a trusted key named "kmk" of length 32 bytes:
  66 +
  67 + $ keyctl add trusted kmk "new 32" @u
  68 + 440502848
  69 +
  70 + $ keyctl show
  71 + Session Keyring
  72 + -3 --alswrv 500 500 keyring: _ses
  73 + 97833714 --alswrv 500 -1 \_ keyring: _uid.500
  74 + 440502848 --alswrv 500 500 \_ trusted: kmk
  75 +
  76 + $ keyctl print 440502848
  77 + 0101000000000000000001005d01b7e3f4a6be5709930f3b70a743cbb42e0cc95e18e915
  78 + 3f60da455bbf1144ad12e4f92b452f966929f6105fd29ca28e4d4d5a031d068478bacb0b
  79 + 27351119f822911b0a11ba3d3498ba6a32e50dac7f32894dd890eb9ad578e4e292c83722
  80 + a52e56a097e6a68b3f56f7a52ece0cdccba1eb62cad7d817f6dc58898b3ac15f36026fec
  81 + d568bd4a706cb60bb37be6d8f1240661199d640b66fb0fe3b079f97f450b9ef9c22c6d5d
  82 + dd379f0facd1cd020281dfa3c70ba21a3fa6fc2471dc6d13ecf8298b946f65345faa5ef0
  83 + f1f8fff03ad0acb083725535636addb08d73dedb9832da198081e5deae84bfaf0409c22b
  84 + e4a8aea2b607ec96931e6f4d4fe563ba
  85 +
  86 + $ keyctl pipe 440502848 > kmk.blob
  87 +
  88 +Load a trusted key from the saved blob:
  89 +
  90 + $ keyctl add trusted kmk "load `cat kmk.blob`" @u
  91 + 268728824
  92 +
  93 + $ keyctl print 268728824
  94 + 0101000000000000000001005d01b7e3f4a6be5709930f3b70a743cbb42e0cc95e18e915
  95 + 3f60da455bbf1144ad12e4f92b452f966929f6105fd29ca28e4d4d5a031d068478bacb0b
  96 + 27351119f822911b0a11ba3d3498ba6a32e50dac7f32894dd890eb9ad578e4e292c83722
  97 + a52e56a097e6a68b3f56f7a52ece0cdccba1eb62cad7d817f6dc58898b3ac15f36026fec
  98 + d568bd4a706cb60bb37be6d8f1240661199d640b66fb0fe3b079f97f450b9ef9c22c6d5d
  99 + dd379f0facd1cd020281dfa3c70ba21a3fa6fc2471dc6d13ecf8298b946f65345faa5ef0
  100 + f1f8fff03ad0acb083725535636addb08d73dedb9832da198081e5deae84bfaf0409c22b
  101 + e4a8aea2b607ec96931e6f4d4fe563ba
  102 +
  103 +Reseal a trusted key under new pcr values:
  104 +
  105 + $ keyctl update 268728824 "update pcrinfo=`cat pcr.blob`"
  106 + $ keyctl print 268728824
  107 + 010100000000002c0002800093c35a09b70fff26e7a98ae786c641e678ec6ffb6b46d805
  108 + 77c8a6377aed9d3219c6dfec4b23ffe3000001005d37d472ac8a44023fbb3d18583a4f73
  109 + d3a076c0858f6f1dcaa39ea0f119911ff03f5406df4f7f27f41da8d7194f45c9f4e00f2e
  110 + df449f266253aa3f52e55c53de147773e00f0f9aca86c64d94c95382265968c354c5eab4
  111 + 9638c5ae99c89de1e0997242edfb0b501744e11ff9762dfd951cffd93227cc513384e7e6
  112 + e782c29435c7ec2edafaa2f4c1fe6e7a781b59549ff5296371b42133777dcc5b8b971610
  113 + 94bc67ede19e43ddb9dc2baacad374a36feaf0314d700af0a65c164b7082401740e489c9
  114 + 7ef6a24defe4846104209bf0c3eced7fa1a672ed5b125fc9d8cd88b476a658a4434644ef
  115 + df8ae9a178e9f83ba9f08d10fa47e4226b98b0702f06b3b8
  116 +
  117 +Create and save an encrypted key "evm" using the above trusted key "kmk":
  118 +
  119 + $ keyctl add encrypted evm "new trusted:kmk 32" @u
  120 + 159771175
  121 +
  122 + $ keyctl print 159771175
  123 + trusted:kmk 32 2375725ad57798846a9bbd240de8906f006e66c03af53b1b382dbbc55
  124 + be2a44616e4959430436dc4f2a7a9659aa60bb4652aeb2120f149ed197c564e024717c64
  125 + 5972dcb82ab2dde83376d82b2e3c09ffc
  126 +
  127 + $ keyctl pipe 159771175 > evm.blob
  128 +
  129 +Load an encrypted key "evm" from saved blob:
  130 +
  131 + $ keyctl add encrypted evm "load `cat evm.blob`" @u
  132 + 831684262
  133 +
  134 + $ keyctl print 831684262
  135 + trusted:kmk 32 2375725ad57798846a9bbd240de8906f006e66c03af53b1b382dbbc55
  136 + be2a44616e4959430436dc4f2a7a9659aa60bb4652aeb2120f149ed197c564e024717c64
  137 + 5972dcb82ab2dde83376d82b2e3c09ffc
  138 +
  139 +
  140 +The initial consumer of trusted keys is EVM, which at boot time needs a high
  141 +quality symmetric key for HMAC protection of file metadata. The use of a
  142 +trusted key provides strong guarantees that the EVM key has not been
  143 +compromised by a user level problem, and when sealed to specific boot PCR
  144 +values, protects against boot and offline attacks. Other uses for trusted and
  145 +encrypted keys, such as for disk and file encryption are anticipated.
include/keys/trusted-type.h
Diff comments   View file @ d00a1c7
  1 +/*
  2 + * Copyright (C) 2010 IBM Corporation
  3 + * Author: David Safford <safford@us.ibm.com>
  4 + *
  5 + * This program is free software; you can redistribute it and/or modify
  6 + * it under the terms of the GNU General Public License as published by
  7 + * the Free Software Foundation, version 2 of the License.
  8 + */
  9 +
  10 +#ifndef _KEYS_TRUSTED_TYPE_H
  11 +#define _KEYS_TRUSTED_TYPE_H
  12 +
  13 +#include <linux/key.h>
  14 +#include <linux/rcupdate.h>
  15 +
  16 +#define MIN_KEY_SIZE 32
  17 +#define MAX_KEY_SIZE 128
  18 +#define MAX_BLOB_SIZE 320
  19 +
  20 +struct trusted_key_payload {
  21 + struct rcu_head rcu;
  22 + unsigned int key_len;
  23 + unsigned int blob_len;
  24 + unsigned char migratable;
  25 + unsigned char key[MAX_KEY_SIZE + 1];
  26 + unsigned char blob[MAX_BLOB_SIZE];
  27 +};
  28 +
  29 +extern struct key_type key_type_trusted;
  30 +
  31 +#endif /* _KEYS_TRUSTED_TYPE_H */
include/linux/tpm_command.h
Diff comments   View file @ d00a1c7
  1 +#ifndef __LINUX_TPM_COMMAND_H__
  2 +#define __LINUX_TPM_COMMAND_H__
  3 +
  4 +/*
  5 + * TPM Command constants from specifications at
  6 + * http://www.trustedcomputinggroup.org
  7 + */
  8 +
  9 +/* Command TAGS */
  10 +#define TPM_TAG_RQU_COMMAND 193
  11 +#define TPM_TAG_RQU_AUTH1_COMMAND 194
  12 +#define TPM_TAG_RQU_AUTH2_COMMAND 195
  13 +#define TPM_TAG_RSP_COMMAND 196
  14 +#define TPM_TAG_RSP_AUTH1_COMMAND 197
  15 +#define TPM_TAG_RSP_AUTH2_COMMAND 198
  16 +
  17 +/* Command Ordinals */
  18 +#define TPM_ORD_GETRANDOM 70
  19 +#define TPM_ORD_OSAP 11
  20 +#define TPM_ORD_OIAP 10
  21 +#define TPM_ORD_SEAL 23
  22 +#define TPM_ORD_UNSEAL 24
  23 +
  24 +/* Other constants */
  25 +#define SRKHANDLE 0x40000000
  26 +#define TPM_NONCE_SIZE 20
  27 +
  28 +#endif
... ... @@ -21,6 +21,21 @@
21 21  
22 22 If you are unsure as to whether this is required, answer N.
23 23  
  24 +config TRUSTED_KEYS
  25 + tristate "TRUSTED KEYS"
  26 + depends on KEYS && TCG_TPM
  27 + select CRYPTO
  28 + select CRYPTO_HMAC
  29 + select CRYPTO_SHA1
  30 + help
  31 + This option provides support for creating, sealing, and unsealing
  32 + keys in the kernel. Trusted keys are random number symmetric keys,
  33 + generated and RSA-sealed by the TPM. The TPM only unseals the keys,
  34 + if the boot PCRs and other criteria match. Userspace will only ever
  35 + see encrypted blobs.
  36 +
  37 + If you are unsure as to whether this is required, answer N.
  38 +
24 39 config KEYS_DEBUG_PROC_KEYS
25 40 bool "Enable the /proc/keys file by which keys may be viewed"
26 41 depends on KEYS
security/keys/Makefile
Diff comments   View file @ d00a1c7
... ... @@ -13,6 +13,7 @@
13 13 request_key_auth.o \
14 14 user_defined.o
15 15  
  16 +obj-$(CONFIG_TRUSTED_KEYS) += trusted_defined.o
16 17 obj-$(CONFIG_KEYS_COMPAT) += compat.o
17 18 obj-$(CONFIG_PROC_FS) += proc.o
18 19 obj-$(CONFIG_SYSCTL) += sysctl.o
security/keys/trusted_defined.c
Diff comments   View file @ d00a1c7
Changes suppressed. Click to show
  1 +/*
  2 + * Copyright (C) 2010 IBM Corporation
  3 + *
  4 + * Author:
  5 + * David Safford <safford@us.ibm.com>
  6 + *
  7 + * This program is free software; you can redistribute it and/or modify
  8 + * it under the terms of the GNU General Public License as published by
  9 + * the Free Software Foundation, version 2 of the License.
  10 + *
  11 + * See Documentation/keys-trusted-encrypted.txt
  12 + */
  13 +
  14 +#include <linux/uaccess.h>
  15 +#include <linux/module.h>
  16 +#include <linux/init.h>
  17 +#include <linux/slab.h>
  18 +#include <linux/parser.h>
  19 +#include <linux/string.h>
  20 +#include <keys/user-type.h>
  21 +#include <keys/trusted-type.h>
  22 +#include <linux/key-type.h>
  23 +#include <linux/rcupdate.h>
  24 +#include <linux/crypto.h>
  25 +#include <crypto/hash.h>
  26 +#include <crypto/sha.h>
  27 +#include <linux/capability.h>
  28 +#include <linux/tpm.h>
  29 +#include <linux/tpm_command.h>
  30 +
  31 +#include "trusted_defined.h"
  32 +
  33 +static const char hmac_alg[] = "hmac(sha1)";
  34 +static const char hash_alg[] = "sha1";
  35 +
  36 +struct sdesc {
  37 + struct shash_desc shash;
  38 + char ctx[];
  39 +};
  40 +
  41 +static struct crypto_shash *hashalg;
  42 +static struct crypto_shash *hmacalg;
  43 +
  44 +static struct sdesc *init_sdesc(struct crypto_shash *alg)
  45 +{
  46 + struct sdesc *sdesc;
  47 + int size;
  48 +
  49 + size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
  50 + sdesc = kmalloc(size, GFP_KERNEL);
  51 + if (!sdesc)
  52 + return ERR_PTR(-ENOMEM);
  53 + sdesc->shash.tfm = alg;
  54 + sdesc->shash.flags = 0x0;
  55 + return sdesc;
  56 +}
  57 +
  58 +static int TSS_sha1(const unsigned char *data, const unsigned int datalen,
  59 + unsigned char *digest)
  60 +{
  61 + struct sdesc *sdesc;
  62 + int ret;
  63 +
  64 + sdesc = init_sdesc(hashalg);
  65 + if (IS_ERR(sdesc)) {
  66 + pr_info("trusted_key: can't alloc %s\n", hash_alg);
  67 + return PTR_ERR(sdesc);
  68 + }
  69 +
  70 + ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
  71 + kfree(sdesc);
  72 + return ret;
  73 +}
  74 +
  75 +static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
  76 + const unsigned int keylen, ...)
  77 +{
  78 + struct sdesc *sdesc;
  79 + va_list argp;
  80 + unsigned int dlen;
  81 + unsigned char *data;
  82 + int ret;
  83 +
  84 + sdesc = init_sdesc(hmacalg);
  85 + if (IS_ERR(sdesc)) {
  86 + pr_info("trusted_key: can't alloc %s\n", hmac_alg);
  87 + return PTR_ERR(sdesc);
  88 + }
  89 +
  90 + ret = crypto_shash_setkey(hmacalg, key, keylen);
  91 + if (ret < 0)
  92 + goto out;
  93 + ret = crypto_shash_init(&sdesc->shash);
  94 + if (ret < 0)
  95 + goto out;
  96 +
  97 + va_start(argp, keylen);
  98 + for (;;) {
  99 + dlen = va_arg(argp, unsigned int);
  100 + if (dlen == 0)
  101 + break;
  102 + data = va_arg(argp, unsigned char *);
  103 + if (data == NULL)
  104 + return -EINVAL;
  105 + ret = crypto_shash_update(&sdesc->shash, data, dlen);
  106 + if (ret < 0)
  107 + goto out;
  108 + }
  109 + va_end(argp);
  110 + ret = crypto_shash_final(&sdesc->shash, digest);
  111 +out:
  112 + kfree(sdesc);
  113 + return ret;
  114 +}
  115 +
  116 +/*
  117 + * calculate authorization info fields to send to TPM
  118 + */
  119 +static uint32_t TSS_authhmac(unsigned char *digest, const unsigned char *key,
  120 + const unsigned int keylen, unsigned char *h1,
  121 + unsigned char *h2, unsigned char h3, ...)
  122 +{
  123 + unsigned char paramdigest[SHA1_DIGEST_SIZE];
  124 + struct sdesc *sdesc;
  125 + unsigned int dlen;
  126 + unsigned char *data;
  127 + unsigned char c;
  128 + int ret;
  129 + va_list argp;
  130 +
  131 + sdesc = init_sdesc(hashalg);
  132 + if (IS_ERR(sdesc)) {
  133 + pr_info("trusted_key: can't alloc %s\n", hash_alg);
  134 + return PTR_ERR(sdesc);
  135 + }
  136 +
  137 + c = h3;
  138 + ret = crypto_shash_init(&sdesc->shash);
  139 + if (ret < 0)
  140 + goto out;
  141 + va_start(argp, h3);
  142 + for (;;) {
  143 + dlen = va_arg(argp, unsigned int);
  144 + if (dlen == 0)
  145 + break;
  146 + data = va_arg(argp, unsigned char *);
  147 + ret = crypto_shash_update(&sdesc->shash, data, dlen);
  148 + if (ret < 0)
  149 + goto out;
  150 + }
  151 + va_end(argp);
  152 + ret = crypto_shash_final(&sdesc->shash, paramdigest);
  153 + if (!ret)
  154 + TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE,
  155 + paramdigest, TPM_NONCE_SIZE, h1,
  156 + TPM_NONCE_SIZE, h2, 1, &c, 0, 0);
  157 +out:
  158 + kfree(sdesc);
  159 + return ret;
  160 +}
  161 +
  162 +/*
  163 + * verify the AUTH1_COMMAND (Seal) result from TPM
  164 + */
  165 +static uint32_t TSS_checkhmac1(unsigned char *buffer,
  166 + const uint32_t command,
  167 + const unsigned char *ononce,
  168 + const unsigned char *key,
  169 + const unsigned int keylen, ...)
  170 +{
  171 + uint32_t bufsize;
  172 + uint16_t tag;
  173 + uint32_t ordinal;
  174 + uint32_t result;
  175 + unsigned char *enonce;
  176 + unsigned char *continueflag;
  177 + unsigned char *authdata;
  178 + unsigned char testhmac[SHA1_DIGEST_SIZE];
  179 + unsigned char paramdigest[SHA1_DIGEST_SIZE];
  180 + struct sdesc *sdesc;
  181 + unsigned int dlen;
  182 + unsigned int dpos;
  183 + va_list argp;
  184 + int ret;
  185 +
  186 + bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
  187 + tag = LOAD16(buffer, 0);
  188 + ordinal = command;
  189 + result = LOAD32N(buffer, TPM_RETURN_OFFSET);
  190 + if (tag == TPM_TAG_RSP_COMMAND)
  191 + return 0;
  192 + if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
  193 + return -EINVAL;
  194 + authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
  195 + continueflag = authdata - 1;
  196 + enonce = continueflag - TPM_NONCE_SIZE;
  197 +
  198 + sdesc = init_sdesc(hashalg);
  199 + if (IS_ERR(sdesc)) {
  200 + pr_info("trusted_key: can't alloc %s\n", hash_alg);
  201 + return PTR_ERR(sdesc);
  202 + }
  203 + ret = crypto_shash_init(&sdesc->shash);
  204 + if (ret < 0)
  205 + goto out;
  206 + ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
  207 + sizeof result);
  208 + if (ret < 0)
  209 + goto out;
  210 + ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
  211 + sizeof ordinal);
  212 + if (ret < 0)
  213 + goto out;
  214 + va_start(argp, keylen);
  215 + for (;;) {
  216 + dlen = va_arg(argp, unsigned int);
  217 + if (dlen == 0)
  218 + break;
  219 + dpos = va_arg(argp, unsigned int);
  220 + ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
  221 + if (ret < 0)
  222 + goto out;
  223 + }
  224 + va_end(argp);
  225 + ret = crypto_shash_final(&sdesc->shash, paramdigest);
  226 + if (ret < 0)
  227 + goto out;
  228 + ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
  229 + TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
  230 + 1, continueflag, 0, 0);
  231 + if (ret < 0)
  232 + goto out;
  233 + if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
  234 + ret = -EINVAL;
  235 +out:
  236 + kfree(sdesc);
  237 + return ret;
  238 +}
  239 +
  240 +/*
  241 + * verify the AUTH2_COMMAND (unseal) result from TPM
  242 + */
  243 +static uint32_t TSS_checkhmac2(unsigned char *buffer,
  244 + const uint32_t command,
  245 + const unsigned char *ononce,
  246 + const unsigned char *key1,
  247 + const unsigned int keylen1,
  248 + const unsigned char *key2,
  249 + const unsigned int keylen2, ...)
  250 +{
  251 + uint32_t bufsize;
  252 + uint16_t tag;
  253 + uint32_t ordinal;
  254 + uint32_t result;
  255 + unsigned char *enonce1;
  256 + unsigned char *continueflag1;
  257 + unsigned char *authdata1;
  258 + unsigned char *enonce2;
  259 + unsigned char *continueflag2;
  260 + unsigned char *authdata2;
  261 + unsigned char testhmac1[SHA1_DIGEST_SIZE];
  262 + unsigned char testhmac2[SHA1_DIGEST_SIZE];
  263 + unsigned char paramdigest[SHA1_DIGEST_SIZE];
  264 + struct sdesc *sdesc;
  265 + unsigned int dlen;
  266 + unsigned int dpos;
  267 + va_list argp;
  268 + int ret;
  269 +
  270 + bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
  271 + tag = LOAD16(buffer, 0);
  272 + ordinal = command;
  273 + result = LOAD32N(buffer, TPM_RETURN_OFFSET);
  274 +
  275 + if (tag == TPM_TAG_RSP_COMMAND)
  276 + return 0;
  277 + if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
  278 + return -EINVAL;
  279 + authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1
  280 + + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE);
  281 + authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE);
  282 + continueflag1 = authdata1 - 1;
  283 + continueflag2 = authdata2 - 1;
  284 + enonce1 = continueflag1 - TPM_NONCE_SIZE;
  285 + enonce2 = continueflag2 - TPM_NONCE_SIZE;
  286 +
  287 + sdesc = init_sdesc(hashalg);
  288 + if (IS_ERR(sdesc)) {
  289 + pr_info("trusted_key: can't alloc %s\n", hash_alg);
  290 + return PTR_ERR(sdesc);
  291 + }
  292 + ret = crypto_shash_init(&sdesc->shash);
  293 + if (ret < 0)
  294 + goto out;
  295 + ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
  296 + sizeof result);
  297 + if (ret < 0)
  298 + goto out;
  299 + ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
  300 + sizeof ordinal);
  301 + if (ret < 0)
  302 + goto out;
  303 +
  304 + va_start(argp, keylen2);
  305 + for (;;) {
  306 + dlen = va_arg(argp, unsigned int);
  307 + if (dlen == 0)
  308 + break;
  309 + dpos = va_arg(argp, unsigned int);
  310 + ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
  311 + if (ret < 0)
  312 + goto out;
  313 + }
  314 + ret = crypto_shash_final(&sdesc->shash, paramdigest);
  315 + if (ret < 0)
  316 + goto out;
  317 +
  318 + ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE,
  319 + paramdigest, TPM_NONCE_SIZE, enonce1,
  320 + TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0);
  321 + if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) {
  322 + ret = -EINVAL;
  323 + goto out;
  324 + }
  325 + ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE,
  326 + paramdigest, TPM_NONCE_SIZE, enonce2,
  327 + TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0);
  328 + if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE))
  329 + ret = -EINVAL;
  330 +out:
  331 + kfree(sdesc);
  332 + return ret;
  333 +}
  334 +
  335 +/*
  336 + * For key specific tpm requests, we will generate and send our
  337 + * own TPM command packets using the drivers send function.
  338 + */
  339 +static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd,
  340 + size_t buflen)
  341 +{
  342 + int rc;
  343 +
  344 + dump_tpm_buf(cmd);
  345 + rc = tpm_send(chip_num, cmd, buflen);
  346 + dump_tpm_buf(cmd);
  347 + if (rc > 0)
  348 + /* Can't return positive return codes values to keyctl */
  349 + rc = -EPERM;
  350 + return rc;
  351 +}
  352 +
  353 +/*
  354 + * get a random value from TPM
  355 + */
  356 +static int tpm_get_random(struct tpm_buf *tb, unsigned char *buf, uint32_t len)
  357 +{
  358 + int ret;
  359 +
  360 + INIT_BUF(tb);
  361 + store16(tb, TPM_TAG_RQU_COMMAND);
  362 + store32(tb, TPM_GETRANDOM_SIZE);
  363 + store32(tb, TPM_ORD_GETRANDOM);
  364 + store32(tb, len);
  365 + ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, sizeof tb->data);
  366 + memcpy(buf, tb->data + TPM_GETRANDOM_SIZE, len);
  367 +
  368 + return ret;
  369 +}
  370 +
  371 +static int my_get_random(unsigned char *buf, int len)
  372 +{
  373 + struct tpm_buf *tb;
  374 + int ret;
  375 +
  376 + tb = kzalloc(sizeof *tb, GFP_KERNEL);
  377 + if (!tb)
  378 + return -ENOMEM;
  379 + ret = tpm_get_random(tb, buf, len);
  380 +
  381 + kfree(tb);
  382 + return ret;
  383 +}
  384 +
  385 +/*
  386 + * Lock a trusted key, by extending a selected PCR.
  387 + *
  388 + * Prevents a trusted key that is sealed to PCRs from being accessed.
  389 + * This uses the tpm driver's extend function.
  390 + */
  391 +static int pcrlock(const int pcrnum)
  392 +{
  393 + unsigned char hash[SHA1_DIGEST_SIZE];
  394 +
  395 + if (!capable(CAP_SYS_ADMIN))
  396 + return -EPERM;
  397 + my_get_random(hash, SHA1_DIGEST_SIZE);
  398 + return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0;
  399 +}
  400 +
  401 +/*
  402 + * Create an object specific authorisation protocol (OSAP) session
  403 + */
  404 +static int osap(struct tpm_buf *tb, struct osapsess *s,
  405 + const unsigned char *key, const uint16_t type,
  406 + const uint32_t handle)
  407 +{
  408 + unsigned char enonce[TPM_NONCE_SIZE];
  409 + unsigned char ononce[TPM_NONCE_SIZE];
  410 + int ret;
  411 +
  412 + ret = tpm_get_random(tb, ononce, TPM_NONCE_SIZE);
  413 + if (ret < 0)
  414 + return ret;
  415 +
  416 + INIT_BUF(tb);
  417 + store16(tb, TPM_TAG_RQU_COMMAND);
  418 + store32(tb, TPM_OSAP_SIZE);
  419 + store32(tb, TPM_ORD_OSAP);
  420 + store16(tb, type);
  421 + store32(tb, handle);
  422 + storebytes(tb, ononce, TPM_NONCE_SIZE);
  423 +
  424 + ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
  425 + if (ret < 0)
  426 + return ret;
  427 +
  428 + s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
  429 + memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
  430 + TPM_NONCE_SIZE);
  431 + memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
  432 + TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
  433 + ret = TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
  434 + enonce, TPM_NONCE_SIZE, ononce, 0, 0);
  435 + return ret;
  436 +}
  437 +
  438 +/*
  439 + * Create an object independent authorisation protocol (oiap) session
  440 + */
  441 +static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
  442 +{
  443 + int ret;
  444 +
  445 + INIT_BUF(tb);
  446 + store16(tb, TPM_TAG_RQU_COMMAND);
  447 + store32(tb, TPM_OIAP_SIZE);
  448 + store32(tb, TPM_ORD_OIAP);
  449 + ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
  450 + if (ret < 0)
  451 + return ret;
  452 +
  453 + *handle = LOAD32(tb->data, TPM_DATA_OFFSET);
  454 + memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
  455 + TPM_NONCE_SIZE);
  456 + return ret;
  457 +}
  458 +
  459 +struct tpm_digests {
  460 + unsigned char encauth[SHA1_DIGEST_SIZE];
  461 + unsigned char pubauth[SHA1_DIGEST_SIZE];
  462 + unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
  463 + unsigned char xorhash[SHA1_DIGEST_SIZE];
  464 + unsigned char nonceodd[TPM_NONCE_SIZE];
  465 +};
  466 +
  467 +/*
  468 + * Have the TPM seal(encrypt) the trusted key, possibly based on
  469 + * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
  470 + */
  471 +static int tpm_seal(struct tpm_buf *tb, const uint16_t keytype,
  472 + const uint32_t keyhandle, const unsigned char *keyauth,
  473 + const unsigned char *data, const uint32_t datalen,
  474 + unsigned char *blob, uint32_t *bloblen,
  475 + const unsigned char *blobauth,
  476 + const unsigned char *pcrinfo, const uint32_t pcrinfosize)
  477 +{
  478 + struct osapsess sess;
  479 + struct tpm_digests *td;
  480 + unsigned char cont;
  481 + uint32_t ordinal;
  482 + uint32_t pcrsize;
  483 + uint32_t datsize;
  484 + int sealinfosize;
  485 + int encdatasize;
  486 + int storedsize;
  487 + int ret;
  488 + int i;
  489 +
  490 + /* alloc some work space for all the hashes */
  491 + td = kmalloc(sizeof *td, GFP_KERNEL);
  492 + if (!td)
  493 + return -ENOMEM;
  494 +
  495 + /* get session for sealing key */
  496 + ret = osap(tb, &sess, keyauth, keytype, keyhandle);
  497 + if (ret < 0)
  498 + return ret;
  499 + dump_sess(&sess);
  500 +
  501 + /* calculate encrypted authorization value */
  502 + memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
  503 + memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
  504 + ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
  505 + if (ret < 0)
  506 + return ret;
  507 +
  508 + ret = tpm_get_random(tb, td->nonceodd, TPM_NONCE_SIZE);
  509 + if (ret < 0)
  510 + return ret;
  511 + ordinal = htonl(TPM_ORD_SEAL);
  512 + datsize = htonl(datalen);
  513 + pcrsize = htonl(pcrinfosize);
  514 + cont = 0;
  515 +
  516 + /* encrypt data authorization key */
  517 + for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
  518 + td->encauth[i] = td->xorhash[i] ^ blobauth[i];
  519 +
  520 + /* calculate authorization HMAC value */
  521 + if (pcrinfosize == 0) {
  522 + /* no pcr info specified */
  523 + TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
  524 + sess.enonce, td->nonceodd, cont, sizeof(uint32_t),
  525 + &ordinal, SHA1_DIGEST_SIZE, td->encauth,
  526 + sizeof(uint32_t), &pcrsize, sizeof(uint32_t),
  527 + &datsize, datalen, data, 0, 0);
  528 + } else {
  529 + /* pcr info specified */
  530 + TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
  531 + sess.enonce, td->nonceodd, cont, sizeof(uint32_t),
  532 + &ordinal, SHA1_DIGEST_SIZE, td->encauth,
  533 + sizeof(uint32_t), &pcrsize, pcrinfosize,
  534 + pcrinfo, sizeof(uint32_t), &datsize, datalen,
  535 + data, 0, 0);
  536 + }
  537 +
  538 + /* build and send the TPM request packet */
  539 + INIT_BUF(tb);
  540 + store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
  541 + store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen);
  542 + store32(tb, TPM_ORD_SEAL);
  543 + store32(tb, keyhandle);
  544 + storebytes(tb, td->encauth, SHA1_DIGEST_SIZE);
  545 + store32(tb, pcrinfosize);
  546 + storebytes(tb, pcrinfo, pcrinfosize);
  547 + store32(tb, datalen);
  548 + storebytes(tb, data, datalen);
  549 + store32(tb, sess.handle);
  550 + storebytes(tb, td->nonceodd, TPM_NONCE_SIZE);
  551 + store8(tb, cont);
  552 + storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE);
  553 +
  554 + ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
  555 + if (ret < 0)
  556 + return ret;
  557 +
  558 + /* calculate the size of the returned Blob */
  559 + sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
  560 + encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
  561 + sizeof(uint32_t) + sealinfosize);
  562 + storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
  563 + sizeof(uint32_t) + encdatasize;
  564 +
  565 + /* check the HMAC in the response */
  566 + ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
  567 + SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
  568 + 0);
  569 +
  570 + /* copy the returned blob to caller */
  571 + memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
  572 + *bloblen = storedsize;
  573 + return ret;
  574 +}
  575 +
  576 +/*
  577 + * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
  578 + */
  579 +static int tpm_unseal(struct tpm_buf *tb,
  580 + const uint32_t keyhandle, const unsigned char *keyauth,
  581 + const unsigned char *blob, const int bloblen,
  582 + const unsigned char *blobauth,
  583 + unsigned char *data, unsigned int *datalen)
  584 +{
  585 + unsigned char nonceodd[TPM_NONCE_SIZE];
  586 + unsigned char enonce1[TPM_NONCE_SIZE];
  587 + unsigned char enonce2[TPM_NONCE_SIZE];
  588 + unsigned char authdata1[SHA1_DIGEST_SIZE];
  589 + unsigned char authdata2[SHA1_DIGEST_SIZE];
  590 + uint32_t authhandle1 = 0;
  591 + uint32_t authhandle2 = 0;
  592 + unsigned char cont = 0;
  593 + uint32_t ordinal;
  594 + uint32_t keyhndl;
  595 + int ret;
  596 +
  597 + /* sessions for unsealing key and data */
  598 + ret = oiap(tb, &authhandle1, enonce1);
  599 + if (ret < 0) {
  600 + pr_info("trusted_key: oiap failed (%d)\n", ret);
  601 + return ret;
  602 + }
  603 + ret = oiap(tb, &authhandle2, enonce2);
  604 + if (ret < 0) {
  605 + pr_info("trusted_key: oiap failed (%d)\n", ret);
  606 + return ret;
  607 + }
  608 +
  609 + ordinal = htonl(TPM_ORD_UNSEAL);
  610 + keyhndl = htonl(SRKHANDLE);
  611 + ret = tpm_get_random(tb, nonceodd, TPM_NONCE_SIZE);
  612 + if (ret < 0) {
  613 + pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
  614 + return ret;
  615 + }
  616 + TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
  617 + enonce1, nonceodd, cont, sizeof(uint32_t),
  618 + &ordinal, bloblen, blob, 0, 0);
  619 + TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
  620 + enonce2, nonceodd, cont, sizeof(uint32_t),
  621 + &ordinal, bloblen, blob, 0, 0);
  622 +
  623 + /* build and send TPM request packet */
  624 + INIT_BUF(tb);
  625 + store16(tb, TPM_TAG_RQU_AUTH2_COMMAND);
  626 + store32(tb, TPM_UNSEAL_SIZE + bloblen);
  627 + store32(tb, TPM_ORD_UNSEAL);
  628 + store32(tb, keyhandle);
  629 + storebytes(tb, blob, bloblen);
  630 + store32(tb, authhandle1);
  631 + storebytes(tb, nonceodd, TPM_NONCE_SIZE);
  632 + store8(tb, cont);
  633 + storebytes(tb, authdata1, SHA1_DIGEST_SIZE);
  634 + store32(tb, authhandle2);
  635 + storebytes(tb, nonceodd, TPM_NONCE_SIZE);
  636 + store8(tb, cont);
  637 + storebytes(tb, authdata2, SHA1_DIGEST_SIZE);
  638 +
  639 + ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
  640 + if (ret < 0) {
  641 + pr_info("trusted_key: authhmac failed (%d)\n", ret);
  642 + return ret;
  643 + }
  644 +
  645 + *datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
  646 + ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
  647 + keyauth, SHA1_DIGEST_SIZE,
  648 + blobauth, SHA1_DIGEST_SIZE,
  649 + sizeof(uint32_t), TPM_DATA_OFFSET,
  650 + *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
  651 + 0);
  652 + if (ret < 0)
  653 + pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret);
  654 + memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
  655 + return ret;
  656 +}
  657 +
  658 +/*
  659 + * Have the TPM seal(encrypt) the symmetric key
  660 + */
  661 +static int key_seal(struct trusted_key_payload *p,
  662 + struct trusted_key_options *o)
  663 +{
  664 + struct tpm_buf *tb;
  665 + int ret;
  666 +
  667 + tb = kzalloc(sizeof *tb, GFP_KERNEL);
  668 + if (!tb)
  669 + return -ENOMEM;
  670 +
  671 + /* include migratable flag at end of sealed key */
  672 + p->key[p->key_len] = p->migratable;
  673 +
  674 + ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth,
  675 + p->key, p->key_len + 1, p->blob, &p->blob_len,
  676 + o->blobauth, o->pcrinfo, o->pcrinfo_len);
  677 + if (ret < 0)
  678 + pr_info("trusted_key: srkseal failed (%d)\n", ret);
  679 +
  680 + kfree(tb);
  681 + return ret;
  682 +}
  683 +
  684 +/*
  685 + * Have the TPM unseal(decrypt) the symmetric key
  686 + */
  687 +static int key_unseal(struct trusted_key_payload *p,
  688 + struct trusted_key_options *o)
  689 +{
  690 + struct tpm_buf *tb;
  691 + int ret;
  692 +
  693 + tb = kzalloc(sizeof *tb, GFP_KERNEL);
  694 + if (!tb)
  695 + return -ENOMEM;
  696 +
  697 + ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
  698 + o->blobauth, p->key, &p->key_len);
  699 + /* pull migratable flag out of sealed key */
  700 + p->migratable = p->key[--p->key_len];
  701 +
  702 + if (ret < 0)
  703 + pr_info("trusted_key: srkunseal failed (%d)\n", ret);
  704 +
  705 + kfree(tb);
  706 + return ret;
  707 +}
  708 +
  709 +enum {
  710 + Opt_err = -1,
  711 + Opt_new, Opt_load, Opt_update,
  712 + Opt_keyhandle, Opt_keyauth, Opt_blobauth,
  713 + Opt_pcrinfo, Opt_pcrlock, Opt_migratable
  714 +};
  715 +
  716 +static const match_table_t key_tokens = {
  717 + {Opt_new, "new"},
  718 + {Opt_load, "load"},
  719 + {Opt_update, "update"},
  720 + {Opt_keyhandle, "keyhandle=%s"},
  721 + {Opt_keyauth, "keyauth=%s"},
  722 + {Opt_blobauth, "blobauth=%s"},
  723 + {Opt_pcrinfo, "pcrinfo=%s"},
  724 + {Opt_pcrlock, "pcrlock=%s"},
  725 + {Opt_migratable, "migratable=%s"},
  726 + {Opt_err, NULL}
  727 +};
  728 +
  729 +/* can have zero or more token= options */
  730 +static int getoptions(char *c, struct trusted_key_payload *pay,
  731 + struct trusted_key_options *opt)
  732 +{
  733 + substring_t args[MAX_OPT_ARGS];
  734 + char *p = c;
  735 + int token;
  736 + int res;
  737 + unsigned long handle;
  738 + unsigned long lock;
  739 +
  740 + while ((p = strsep(&c, " \t"))) {
  741 + if (*p == '\0' || *p == ' ' || *p == '\t')
  742 + continue;
  743 + token = match_token(p, key_tokens, args);
  744 +
  745 + switch (token) {
  746 + case Opt_pcrinfo:
  747 + opt->pcrinfo_len = strlen(args[0].from) / 2;
  748 + if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
  749 + return -EINVAL;
  750 + hex2bin(opt->pcrinfo, args[0].from, opt->pcrinfo_len);
  751 + break;
  752 + case Opt_keyhandle:
  753 + res = strict_strtoul(args[0].from, 16, &handle);
  754 + if (res < 0)
  755 + return -EINVAL;
  756 + opt->keytype = SEAL_keytype;
  757 + opt->keyhandle = handle;
  758 + break;
  759 + case Opt_keyauth:
  760 + if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
  761 + return -EINVAL;
  762 + hex2bin(opt->keyauth, args[0].from, SHA1_DIGEST_SIZE);
  763 + break;
  764 + case Opt_blobauth:
  765 + if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
  766 + return -EINVAL;
  767 + hex2bin(opt->blobauth, args[0].from, SHA1_DIGEST_SIZE);
  768 + break;
  769 + case Opt_migratable:
  770 + if (*args[0].from == '0')
  771 + pay->migratable = 0;
  772 + else
  773 + return -EINVAL;
  774 + break;
  775 + case Opt_pcrlock:
  776 + res = strict_strtoul(args[0].from, 10, &lock);
  777 + if (res < 0)
  778 + return -EINVAL;
  779 + opt->pcrlock = lock;
  780 + break;
  781 + default:
  782 + return -EINVAL;
  783 + }
  784 + }
  785 + return 0;
  786 +}
  787 +
  788 +/*
  789 + * datablob_parse - parse the keyctl data and fill in the
  790 + * payload and options structures
  791 + *
  792 + * On success returns 0, otherwise -EINVAL.
  793 + */
  794 +static int datablob_parse(char *datablob, struct trusted_key_payload *p,
  795 + struct trusted_key_options *o)
  796 +{
  797 + substring_t args[MAX_OPT_ARGS];
  798 + long keylen;
  799 + int ret = -EINVAL;
  800 + int key_cmd;
  801 + char *c;
  802 +
  803 + /* main command */
  804 + c = strsep(&datablob, " \t");
  805 + if (!c)
  806 + return -EINVAL;
  807 + key_cmd = match_token(c, key_tokens, args);
  808 + switch (key_cmd) {
  809 + case Opt_new:
  810 + /* first argument is key size */
  811 + c = strsep(&datablob, " \t");
  812 + if (!c)
  813 + return -EINVAL;
  814 + ret = strict_strtol(c, 10, &keylen);
  815 + if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
  816 + return -EINVAL;
  817 + p->key_len = keylen;
  818 + ret = getoptions(datablob, p, o);
  819 + if (ret < 0)
  820 + return ret;
  821 + ret = Opt_new;
  822 + break;
  823 + case Opt_load:
  824 + /* first argument is sealed blob */
  825 + c = strsep(&datablob, " \t");
  826 + if (!c)
  827 + return -EINVAL;
  828 + p->blob_len = strlen(c) / 2;
  829 + if (p->blob_len > MAX_BLOB_SIZE)
  830 + return -EINVAL;
  831 + hex2bin(p->blob, c, p->blob_len);
  832 + ret = getoptions(datablob, p, o);
  833 + if (ret < 0)
  834 + return ret;
  835 + ret = Opt_load;
  836 + break;
  837 + case Opt_update:
  838 + /* all arguments are options */
  839 + ret = getoptions(datablob, p, o);
  840 + if (ret < 0)
  841 + return ret;
  842 + ret = Opt_update;
  843 + break;
  844 + case Opt_err:
  845 + return -EINVAL;
  846 + break;
  847 + }
  848 + return ret;
  849 +}
  850 +
  851 +static struct trusted_key_options *trusted_options_alloc(void)
  852 +{
  853 + struct trusted_key_options *options;
  854 +
  855 + options = kzalloc(sizeof *options, GFP_KERNEL);
  856 + if (!options)
  857 + return options;
  858 +
  859 + /* set any non-zero defaults */
  860 + options->keytype = SRK_keytype;
  861 + options->keyhandle = SRKHANDLE;
  862 + return options;
  863 +}
  864 +
  865 +static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
  866 +{
  867 + struct trusted_key_payload *p = NULL;
  868 + int ret;
  869 +
  870 + ret = key_payload_reserve(key, sizeof *p);
  871 + if (ret < 0)
  872 + return p;
  873 + p = kzalloc(sizeof *p, GFP_KERNEL);
  874 +
  875 + /* migratable by default */
  876 + p->migratable = 1;
  877 + return p;
  878 +}
  879 +
  880 +/*
  881 + * trusted_instantiate - create a new trusted key
  882 + *
  883 + * Unseal an existing trusted blob or, for a new key, get a
  884 + * random key, then seal and create a trusted key-type key,
  885 + * adding it to the specified keyring.
  886 + *
  887 + * On success, return 0. Otherwise return errno.
  888 + */
  889 +static int trusted_instantiate(struct key *key, const void *data,
  890 + const size_t datalen)
  891 +{
  892 + struct trusted_key_payload *payload = NULL;
  893 + struct trusted_key_options *options = NULL;
  894 + char *datablob;
  895 + int ret = 0;
  896 + int key_cmd;
  897 +
  898 + if (datalen <= 0 || datalen > 32767 || !data)
  899 + return -EINVAL;
  900 +
  901 + datablob = kmalloc(datalen + 1, GFP_KERNEL);
  902 + if (!datablob)
  903 + return -ENOMEM;
  904 + memcpy(datablob, data, datalen);
  905 + datablob[datalen] = '\0';
  906 +
  907 + options = trusted_options_alloc();
  908 + if (!options) {
  909 + ret = -ENOMEM;
  910 + goto out;
  911 + }
  912 + payload = trusted_payload_alloc(key);
  913 + if (!payload) {
  914 + ret = -ENOMEM;
  915 + goto out;
  916 + }
  917 +
  918 + key_cmd = datablob_parse(datablob, payload, options);
  919 + if (key_cmd < 0) {
  920 + ret = key_cmd;
  921 + goto out;
  922 + }
  923 +
  924 + dump_payload(payload);
  925 + dump_options(options);
  926 +
  927 + switch (key_cmd) {
  928 + case Opt_load:
  929 + ret = key_unseal(payload, options);
  930 + dump_payload(payload);
  931 + dump_options(options);
  932 + if (ret < 0)
  933 + pr_info("trusted_key: key_unseal failed (%d)\n", ret);
  934 + break;
  935 + case Opt_new:
  936 + ret = my_get_random(payload->key, payload->key_len);
  937 + if (ret < 0) {
  938 + pr_info("trusted_key: key_create failed (%d)\n", ret);
  939 + goto out;
  940 + }
  941 + ret = key_seal(payload, options);
  942 + if (ret < 0)
  943 + pr_info("trusted_key: key_seal failed (%d)\n", ret);
  944 + break;
  945 + default:
  946 + ret = -EINVAL;
  947 + goto out;
  948 + }
  949 + if (!ret && options->pcrlock)
  950 + ret = pcrlock(options->pcrlock);
  951 +out:
  952 + kfree(datablob);
  953 + kfree(options);
  954 + if (!ret)
  955 + rcu_assign_pointer(key->payload.data, payload);
  956 + else
  957 + kfree(payload);
  958 + return ret;
  959 +}
  960 +
  961 +static void trusted_rcu_free(struct rcu_head *rcu)
  962 +{
  963 + struct trusted_key_payload *p;
  964 +
  965 + p = container_of(rcu, struct trusted_key_payload, rcu);
  966 + memset(p->key, 0, p->key_len);
  967 + kfree(p);
  968 +}
  969 +
  970 +/*
  971 + * trusted_update - reseal an existing key with new PCR values
  972 + */
  973 +static int trusted_update(struct key *key, const void *data,
  974 + const size_t datalen)
  975 +{
  976 + struct trusted_key_payload *p = key->payload.data;
  977 + struct trusted_key_payload *new_p;
  978 + struct trusted_key_options *new_o;
  979 + char *datablob;
  980 + int ret = 0;
  981 +
  982 + if (!p->migratable)
  983 + return -EPERM;
  984 + if (datalen <= 0 || datalen > 32767 || !data)
  985 + return -EINVAL;
  986 +
  987 + datablob = kmalloc(datalen + 1, GFP_KERNEL);
  988 + if (!datablob)
  989 + return -ENOMEM;
  990 + new_o = trusted_options_alloc();
  991 + if (!new_o) {
  992 + ret = -ENOMEM;
  993 + goto out;
  994 + }
  995 + new_p = trusted_payload_alloc(key);
  996 + if (!new_p) {
  997 + ret = -ENOMEM;
  998 + goto out;
  999 + }
  1000 +
  1001 + memcpy(datablob, data, datalen);
  1002 + datablob[datalen] = '\0';
  1003 + ret = datablob_parse(datablob, new_p, new_o);
  1004 + if (ret != Opt_update) {
  1005 + ret = -EINVAL;
  1006 + goto out;
  1007 + }
  1008 + /* copy old key values, and reseal with new pcrs */
  1009 + new_p->migratable = p->migratable;
  1010 + new_p->key_len = p->key_len;
  1011 + memcpy(new_p->key, p->key, p->key_len);
  1012 + dump_payload(p);
  1013 + dump_payload(new_p);
  1014 +
  1015 + ret = key_seal(new_p, new_o);
  1016 + if (ret < 0) {
  1017 + pr_info("trusted_key: key_seal failed (%d)\n", ret);
  1018 + kfree(new_p);
  1019 + goto out;
  1020 + }
  1021 + if (new_o->pcrlock) {
  1022 + ret = pcrlock(new_o->pcrlock);
  1023 + if (ret < 0) {
  1024 + pr_info("trusted_key: pcrlock failed (%d)\n", ret);
  1025 + kfree(new_p);
  1026 + goto out;
  1027 + }
  1028 + }
  1029 + rcu_assign_pointer(key->payload.data, new_p);
  1030 + call_rcu(&p->rcu, trusted_rcu_free);
  1031 +out:
  1032 + kfree(datablob);
  1033 + kfree(new_o);
  1034 + return ret;
  1035 +}
  1036 +
  1037 +/*
  1038 + * trusted_read - copy the sealed blob data to userspace in hex.
  1039 + * On success, return to userspace the trusted key datablob size.
  1040 + */
  1041 +static long trusted_read(const struct key *key, char __user *buffer,
  1042 + size_t buflen)
  1043 +{
  1044 + struct trusted_key_payload *p;
  1045 + char *ascii_buf;
  1046 + char *bufp;
  1047 + int i;
  1048 +
  1049 + p = rcu_dereference_protected(key->payload.data,
  1050 + rwsem_is_locked(&((struct key *)key)->sem));
  1051 + if (!p)
  1052 + return -EINVAL;
  1053 + if (!buffer || buflen <= 0)
  1054 + return 2 * p->blob_len;
  1055 + ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL);
  1056 + if (!ascii_buf)
  1057 + return -ENOMEM;
  1058 +
  1059 + bufp = ascii_buf;
  1060 + for (i = 0; i < p->blob_len; i++)
  1061 + bufp = pack_hex_byte(bufp, p->blob[i]);
  1062 + if ((copy_to_user(buffer, ascii_buf, 2 * p->blob_len)) != 0) {
  1063 + kfree(ascii_buf);
  1064 + return -EFAULT;
  1065 + }
  1066 + kfree(ascii_buf);
  1067 + return 2 * p->blob_len;
  1068 +}
  1069 +
  1070 +/*
  1071 + * trusted_destroy - before freeing the key, clear the decrypted data
  1072 + */
  1073 +static void trusted_destroy(struct key *key)
  1074 +{
  1075 + struct trusted_key_payload *p = key->payload.data;
  1076 +
  1077 + if (!p)
  1078 + return;
  1079 + memset(p->key, 0, p->key_len);
  1080 + kfree(key->payload.data);
  1081 +}
  1082 +
  1083 +struct key_type key_type_trusted = {
  1084 + .name = "trusted",
  1085 + .instantiate = trusted_instantiate,
  1086 + .update = trusted_update,
  1087 + .match = user_match,
  1088 + .destroy = trusted_destroy,
  1089 + .describe = user_describe,
  1090 + .read = trusted_read,
  1091 +};
  1092 +
  1093 +EXPORT_SYMBOL_GPL(key_type_trusted);
  1094 +
  1095 +static void trusted_shash_release(void)
  1096 +{
  1097 + if (hashalg)
  1098 + crypto_free_shash(hashalg);
  1099 + if (hmacalg)
  1100 + crypto_free_shash(hmacalg);
  1101 +}
  1102 +
  1103 +static int __init trusted_shash_alloc(void)
  1104 +{
  1105 + int ret;
  1106 +
  1107 + hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC);
  1108 + if (IS_ERR(hmacalg)) {
  1109 + pr_info("trusted_key: could not allocate crypto %s\n",
  1110 + hmac_alg);
  1111 + return PTR_ERR(hmacalg);
  1112 + }
  1113 +
  1114 + hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC);
  1115 + if (IS_ERR(hashalg)) {
  1116 + pr_info("trusted_key: could not allocate crypto %s\n",
  1117 + hash_alg);
  1118 + ret = PTR_ERR(hashalg);
  1119 + goto hashalg_fail;
  1120 + }
  1121 +
  1122 + return 0;
  1123 +
  1124 +hashalg_fail:
  1125 + crypto_free_shash(hmacalg);
  1126 + return ret;
  1127 +}
  1128 +
  1129 +static int __init init_trusted(void)
  1130 +{
  1131 + int ret;
  1132 +
  1133 + ret = trusted_shash_alloc();
  1134 + if (ret < 0)
  1135 + return ret;
  1136 + ret = register_key_type(&key_type_trusted);
  1137 + if (ret < 0)
  1138 + trusted_shash_release();
  1139 + return ret;
  1140 +}
  1141 +
  1142 +static void __exit cleanup_trusted(void)
  1143 +{
  1144 + trusted_shash_release();
  1145 + unregister_key_type(&key_type_trusted);
  1146 +}
  1147 +
  1148 +late_initcall(init_trusted);
  1149 +module_exit(cleanup_trusted);
  1150 +
  1151 +MODULE_LICENSE("GPL");
security/keys/trusted_defined.h
Diff comments   View file @ d00a1c7
  1 +#ifndef __TRUSTED_KEY_H
  2 +#define __TRUSTED_KEY_H
  3 +
  4 +/* implementation specific TPM constants */
  5 +#define MAX_PCRINFO_SIZE 64
  6 +#define MAX_BUF_SIZE 512
  7 +#define TPM_GETRANDOM_SIZE 14
  8 +#define TPM_OSAP_SIZE 36
  9 +#define TPM_OIAP_SIZE 10
  10 +#define TPM_SEAL_SIZE 87
  11 +#define TPM_UNSEAL_SIZE 104
  12 +#define TPM_SIZE_OFFSET 2
  13 +#define TPM_RETURN_OFFSET 6
  14 +#define TPM_DATA_OFFSET 10
  15 +
  16 +#define LOAD32(buffer, offset) (ntohl(*(uint32_t *)&buffer[offset]))
  17 +#define LOAD32N(buffer, offset) (*(uint32_t *)&buffer[offset])
  18 +#define LOAD16(buffer, offset) (ntohs(*(uint16_t *)&buffer[offset]))
  19 +
  20 +struct tpm_buf {
  21 + int len;
  22 + unsigned char data[MAX_BUF_SIZE];
  23 +};
  24 +
  25 +#define INIT_BUF(tb) (tb->len = 0)
  26 +
  27 +struct osapsess {
  28 + uint32_t handle;
  29 + unsigned char secret[SHA1_DIGEST_SIZE];
  30 + unsigned char enonce[TPM_NONCE_SIZE];
  31 +};
  32 +
  33 +/* discrete values, but have to store in uint16_t for TPM use */
  34 +enum {
  35 + SEAL_keytype = 1,
  36 + SRK_keytype = 4
  37 +};
  38 +
  39 +struct trusted_key_options {
  40 + uint16_t keytype;
  41 + uint32_t keyhandle;
  42 + unsigned char keyauth[SHA1_DIGEST_SIZE];
  43 + unsigned char blobauth[SHA1_DIGEST_SIZE];
  44 + uint32_t pcrinfo_len;
  45 + unsigned char pcrinfo[MAX_PCRINFO_SIZE];
  46 + int pcrlock;
  47 +};
  48 +
  49 +#define TPM_DEBUG 0
  50 +
  51 +#if TPM_DEBUG
  52 +static inline void dump_options(struct trusted_key_options *o)
  53 +{
  54 + pr_info("trusted_key: sealing key type %d\n", o->keytype);
  55 + pr_info("trusted_key: sealing key handle %0X\n", o->keyhandle);
  56 + pr_info("trusted_key: pcrlock %d\n", o->pcrlock);
  57 + pr_info("trusted_key: pcrinfo %d\n", o->pcrinfo_len);
  58 + print_hex_dump(KERN_INFO, "pcrinfo ", DUMP_PREFIX_NONE,
  59 + 16, 1, o->pcrinfo, o->pcrinfo_len, 0);
  60 +}
  61 +
  62 +static inline void dump_payload(struct trusted_key_payload *p)
  63 +{
  64 + pr_info("trusted_key: key_len %d\n", p->key_len);
  65 + print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE,
  66 + 16, 1, p->key, p->key_len, 0);
  67 + pr_info("trusted_key: bloblen %d\n", p->blob_len);
  68 + print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE,
  69 + 16, 1, p->blob, p->blob_len, 0);
  70 + pr_info("trusted_key: migratable %d\n", p->migratable);
  71 +}
  72 +
  73 +static inline void dump_sess(struct osapsess *s)
  74 +{
  75 + print_hex_dump(KERN_INFO, "trusted-key: handle ", DUMP_PREFIX_NONE,
  76 + 16, 1, &s->handle, 4, 0);
  77 + pr_info("trusted-key: secret:\n");
  78 + print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE,
  79 + 16, 1, &s->secret, SHA1_DIGEST_SIZE, 0);
  80 + pr_info("trusted-key: enonce:\n");
  81 + print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE,
  82 + 16, 1, &s->enonce, SHA1_DIGEST_SIZE, 0);
  83 +}
  84 +
  85 +static inline void dump_tpm_buf(unsigned char *buf)
  86 +{
  87 + int len;
  88 +
  89 + pr_info("\ntrusted-key: tpm buffer\n");
  90 + len = LOAD32(buf, TPM_SIZE_OFFSET);
  91 + print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, 16, 1, buf, len, 0);
  92 +}
  93 +#else
  94 +static inline void dump_options(struct trusted_key_options *o)
  95 +{
  96 +}
  97 +
  98 +static inline void dump_payload(struct trusted_key_payload *p)
  99 +{
  100 +}
  101 +
  102 +static inline void dump_sess(struct osapsess *s)
  103 +{
  104 +}
  105 +
  106 +static inline void dump_tpm_buf(unsigned char *buf)
  107 +{
  108 +}
  109 +#endif
  110 +
  111 +static inline void store8(struct tpm_buf *buf, const unsigned char value)
  112 +{
  113 + buf->data[buf->len++] = value;
  114 +}
  115 +
  116 +static inline void store16(struct tpm_buf *buf, const uint16_t value)
  117 +{
  118 + *(uint16_t *) & buf->data[buf->len] = htons(value);
  119 + buf->len += sizeof value;
  120 +}
  121 +
  122 +static inline void store32(struct tpm_buf *buf, const uint32_t value)
  123 +{
  124 + *(uint32_t *) & buf->data[buf->len] = htonl(value);
  125 + buf->len += sizeof value;
  126 +}
  127 +
  128 +static inline void storebytes(struct tpm_buf *buf, const unsigned char *in,
  129 + const int len)
  130 +{
  131 + memcpy(buf->data + buf->len, in, len);
  132 + buf->len += len;
  133 +}
  134 +#endif