aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorMimi Zohar <zohar@linux.vnet.ibm.com>2010-11-23 17:50:34 -0500
committerJames Morris <jmorris@namei.org>2010-11-28 16:55:25 -0500
commitd00a1c72f7f4661212299e6cb132dfa58030bcdb (patch)
tree2c873e461f42bbf3aea03b7b2e59cea8f941d841
parentc749ba912e87ccebd674ae24b97462176c63732e (diff)
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>
Diffstat
-rw-r--r--Documentation/keys-trusted-encrypted.txt145
-rw-r--r--include/keys/trusted-type.h31
-rw-r--r--include/linux/tpm_command.h28
-rw-r--r--security/Kconfig15
-rw-r--r--security/keys/Makefile1
-rw-r--r--security/keys/trusted_defined.c1151
-rw-r--r--security/keys/trusted_defined.h134
7 files changed, 1505 insertions, 0 deletions
diff --git a/Documentation/keys-trusted-encrypted.txt b/Documentation/keys-trusted-encrypted.txt
new file mode 100644
index 000000000000..8fb79bc1ac4b
--- /dev/null
+++ b/Documentation/keys-trusted-encrypted.txt
@@ -0,0 +1,145 @@
1 Trusted and Encrypted Keys
2
3Trusted and Encrypted Keys are two new key types added to the existing kernel
4key ring service. Both of these new types are variable length symmetic keys,
5and in both cases all keys are created in the kernel, and user space sees,
6stores, and loads only encrypted blobs. Trusted Keys require the availability
7of a Trusted Platform Module (TPM) chip for greater security, while Encrypted
8Keys can be used on any system. All user level blobs, are displayed and loaded
9in hex ascii for convenience, and are integrity verified.
10
11Trusted Keys use a TPM both to generate and to seal the keys. Keys are sealed
12under 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
14integrity 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
16when the kernel and initramfs are updated. The same key can have many saved
17blobs under different PCR values, so multiple boots are easily supported.
18
19By default, trusted keys are sealed under the SRK, which has the default
20authorization value (20 zeros). This can be set at takeownership time with the
21trouser's utility: "tpm_takeownership -u -z".
22
23Usage:
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
43TPM_STORED_DATA format. The key length for new keys are always in bytes.
44Trusted Keys can be 32 - 128 bytes (256 - 1024 bits), the upper limit is to fit
45within the 2048 bit SRK (RSA) keylength, with all necessary structure/padding.
46
47Encrypted keys do not depend on a TPM, and are faster, as they use AES for
48encryption/decryption. New keys are created from kernel generated random
49numbers, 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
51disadvantage of encrypted keys is that if they are not rooted in a trusted key,
52they are only as secure as the user key encrypting them. The master user key
53should therefore be loaded in as secure a way as possible, preferably early in
54boot.
55
56Usage:
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
61where 'key-type' is either 'trusted' or 'user'.
62
63Examples of trusted and encrypted key usage:
64
65Create 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
88Load 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
103Reseal 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
117Create 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
129Load 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
140The initial consumer of trusted keys is EVM, which at boot time needs a high
141quality symmetric key for HMAC protection of file metadata. The use of a
142trusted key provides strong guarantees that the EVM key has not been
143compromised by a user level problem, and when sealed to specific boot PCR
144values, protects against boot and offline attacks. Other uses for trusted and
145encrypted keys, such as for disk and file encryption are anticipated.
diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h
new file mode 100644
index 000000000000..56f82e5c9975
--- /dev/null
+++ b/include/keys/trusted-type.h
@@ -0,0 +1,31 @@
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
20struct 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
29extern struct key_type key_type_trusted;
30
31#endif /* _KEYS_TRUSTED_TYPE_H */
diff --git a/include/linux/tpm_command.h b/include/linux/tpm_command.h
new file mode 100644
index 000000000000..727512e249b5
--- /dev/null
+++ b/include/linux/tpm_command.h
@@ -0,0 +1,28 @@
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
diff --git a/security/Kconfig b/security/Kconfig
index e80da955e687..24b8f9b491b8 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -21,6 +21,21 @@ config KEYS
21 21
22 If you are unsure as to whether this is required, answer N. 22 If you are unsure as to whether this is required, answer N.
23 23
24config 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
24config KEYS_DEBUG_PROC_KEYS 39config KEYS_DEBUG_PROC_KEYS
25 bool "Enable the /proc/keys file by which keys may be viewed" 40 bool "Enable the /proc/keys file by which keys may be viewed"
26 depends on KEYS 41 depends on KEYS
diff --git a/security/keys/Makefile b/security/keys/Makefile
index 74d5447d7df7..fcb107020b4a 100644
--- a/security/keys/Makefile
+++ b/security/keys/Makefile
@@ -13,6 +13,7 @@ obj-y := \
13 request_key_auth.o \ 13 request_key_auth.o \
14 user_defined.o 14 user_defined.o
15 15
16obj-$(CONFIG_TRUSTED_KEYS) += trusted_defined.o
16obj-$(CONFIG_KEYS_COMPAT) += compat.o 17obj-$(CONFIG_KEYS_COMPAT) += compat.o
17obj-$(CONFIG_PROC_FS) += proc.o 18obj-$(CONFIG_PROC_FS) += proc.o
18obj-$(CONFIG_SYSCTL) += sysctl.o 19obj-$(CONFIG_SYSCTL) += sysctl.o
diff --git a/security/keys/trusted_defined.c b/security/keys/trusted_defined.c
new file mode 100644
index 000000000000..1bec72e7596d
--- /dev/null
+++ b/security/keys/trusted_defined.c
@@ -0,0 +1,1151 @@
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
33static const char hmac_alg[] = "hmac(sha1)";
34static const char hash_alg[] = "sha1";
35
36struct sdesc {
37 struct shash_desc shash;
38 char ctx[];
39};
40
41static struct crypto_shash *hashalg;
42static struct crypto_shash *hmacalg;
43
44static 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
58static 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
75static 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);
111out:
112 kfree(sdesc);
113 return ret;
114}
115
116/*
117 * calculate authorization info fields to send to TPM
118 */
119static 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);
157out:
158 kfree(sdesc);
159 return ret;
160}
161
162/*
163 * verify the AUTH1_COMMAND (Seal) result from TPM
164 */
165static 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;
235out:
236 kfree(sdesc);
237 return ret;
238}
239
240/*
241 * verify the AUTH2_COMMAND (unseal) result from TPM
242 */
243static 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;
330out:
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 */
339static 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 */
356static 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
371static 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 */
391static 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 */
404static 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 */
441static 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
459struct 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 */
471static 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 */
579static 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 */
661static 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 */
687static 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
709enum {
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
716static 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 */
730static 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 */
794static 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
851static 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
865static 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 */
889static 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);
951out:
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
961static 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 */
973static 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);
1031out:
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 */
1041static 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 */
1073static 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
1083struct 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
1093EXPORT_SYMBOL_GPL(key_type_trusted);
1094
1095static void trusted_shash_release(void)
1096{
1097 if (hashalg)
1098 crypto_free_shash(hashalg);
1099 if (hmacalg)
1100 crypto_free_shash(hmacalg);
1101}
1102
1103static 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
1124hashalg_fail:
1125 crypto_free_shash(hmacalg);
1126 return ret;
1127}
1128
1129static 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
1142static void __exit cleanup_trusted(void)
1143{
1144 trusted_shash_release();
1145 unregister_key_type(&key_type_trusted);
1146}
1147
1148late_initcall(init_trusted);
1149module_exit(cleanup_trusted);
1150
1151MODULE_LICENSE("GPL");
diff --git a/security/keys/trusted_defined.h b/security/keys/trusted_defined.h
new file mode 100644
index 000000000000..3249fbd2b653
--- /dev/null
+++ b/security/keys/trusted_defined.h
@@ -0,0 +1,134 @@
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
20struct tpm_buf {
21 int len;
22 unsigned char data[MAX_BUF_SIZE];
23};
24
25#define INIT_BUF(tb) (tb->len = 0)
26
27struct 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 */
34enum {
35 SEAL_keytype = 1,
36 SRK_keytype = 4
37};
38
39struct 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
52static 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
62static 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
73static 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
85static 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
94static inline void dump_options(struct trusted_key_options *o)
95{
96}
97
98static inline void dump_payload(struct trusted_key_payload *p)
99{
100}
101
102static inline void dump_sess(struct osapsess *s)
103{
104}
105
106static inline void dump_tpm_buf(unsigned char *buf)
107{
108}
109#endif
110
111static inline void store8(struct tpm_buf *buf, const unsigned char value)
112{
113 buf->data[buf->len++] = value;
114}
115
116static 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
122static 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
128static 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
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-23 15:15:14 -0500