1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2004 IBM Corporation
4 * Copyright (C) 2014 Intel Corporation
5 */
6
7 #include <linux/string.h>
8 #include <linux/err.h>
9 #include <linux/tpm.h>
10 #include <linux/tpm_command.h>
11
12 #include <keys/trusted-type.h>
13 #include <keys/trusted_tpm.h>
14
15 static struct tpm2_hash tpm2_hash_map[] = {
16 {HASH_ALGO_SHA1, TPM_ALG_SHA1},
17 {HASH_ALGO_SHA256, TPM_ALG_SHA256},
18 {HASH_ALGO_SHA384, TPM_ALG_SHA384},
19 {HASH_ALGO_SHA512, TPM_ALG_SHA512},
20 {HASH_ALGO_SM3_256, TPM_ALG_SM3_256},
21 };
22
23 /**
24 * tpm_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer.
25 *
26 * @buf: an allocated tpm_buf instance
27 * @session_handle: session handle
28 * @nonce: the session nonce, may be NULL if not used
29 * @nonce_len: the session nonce length, may be 0 if not used
30 * @attributes: the session attributes
31 * @hmac: the session HMAC or password, may be NULL if not used
32 * @hmac_len: the session HMAC or password length, maybe 0 if not used
33 */
tpm2_buf_append_auth(struct tpm_buf * buf,u32 session_handle,const u8 * nonce,u16 nonce_len,u8 attributes,const u8 * hmac,u16 hmac_len)34 static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle,
35 const u8 *nonce, u16 nonce_len,
36 u8 attributes,
37 const u8 *hmac, u16 hmac_len)
38 {
39 tpm_buf_append_u32(buf, 9 + nonce_len + hmac_len);
40 tpm_buf_append_u32(buf, session_handle);
41 tpm_buf_append_u16(buf, nonce_len);
42
43 if (nonce && nonce_len)
44 tpm_buf_append(buf, nonce, nonce_len);
45
46 tpm_buf_append_u8(buf, attributes);
47 tpm_buf_append_u16(buf, hmac_len);
48
49 if (hmac && hmac_len)
50 tpm_buf_append(buf, hmac, hmac_len);
51 }
52
53 /**
54 * tpm2_seal_trusted() - seal the payload of a trusted key
55 *
56 * @chip: TPM chip to use
57 * @payload: the key data in clear and encrypted form
58 * @options: authentication values and other options
59 *
60 * Return: < 0 on error and 0 on success.
61 */
tpm2_seal_trusted(struct tpm_chip * chip,struct trusted_key_payload * payload,struct trusted_key_options * options)62 int tpm2_seal_trusted(struct tpm_chip *chip,
63 struct trusted_key_payload *payload,
64 struct trusted_key_options *options)
65 {
66 unsigned int blob_len;
67 struct tpm_buf buf;
68 u32 hash;
69 int i;
70 int rc;
71
72 for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
73 if (options->hash == tpm2_hash_map[i].crypto_id) {
74 hash = tpm2_hash_map[i].tpm_id;
75 break;
76 }
77 }
78
79 if (i == ARRAY_SIZE(tpm2_hash_map))
80 return -EINVAL;
81
82 rc = tpm_try_get_ops(chip);
83 if (rc)
84 return rc;
85
86 rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
87 if (rc) {
88 tpm_put_ops(chip);
89 return rc;
90 }
91
92 tpm_buf_append_u32(&buf, options->keyhandle);
93 tpm2_buf_append_auth(&buf, TPM2_RS_PW,
94 NULL /* nonce */, 0,
95 0 /* session_attributes */,
96 options->keyauth /* hmac */,
97 TPM_DIGEST_SIZE);
98
99 /* sensitive */
100 tpm_buf_append_u16(&buf, 4 + options->blobauth_len + payload->key_len + 1);
101
102 tpm_buf_append_u16(&buf, options->blobauth_len);
103 if (options->blobauth_len)
104 tpm_buf_append(&buf, options->blobauth, options->blobauth_len);
105
106 tpm_buf_append_u16(&buf, payload->key_len + 1);
107 tpm_buf_append(&buf, payload->key, payload->key_len);
108 tpm_buf_append_u8(&buf, payload->migratable);
109
110 /* public */
111 tpm_buf_append_u16(&buf, 14 + options->policydigest_len);
112 tpm_buf_append_u16(&buf, TPM_ALG_KEYEDHASH);
113 tpm_buf_append_u16(&buf, hash);
114
115 /* policy */
116 if (options->policydigest_len) {
117 tpm_buf_append_u32(&buf, 0);
118 tpm_buf_append_u16(&buf, options->policydigest_len);
119 tpm_buf_append(&buf, options->policydigest,
120 options->policydigest_len);
121 } else {
122 tpm_buf_append_u32(&buf, TPM2_OA_USER_WITH_AUTH);
123 tpm_buf_append_u16(&buf, 0);
124 }
125
126 /* public parameters */
127 tpm_buf_append_u16(&buf, TPM_ALG_NULL);
128 tpm_buf_append_u16(&buf, 0);
129
130 /* outside info */
131 tpm_buf_append_u16(&buf, 0);
132
133 /* creation PCR */
134 tpm_buf_append_u32(&buf, 0);
135
136 if (buf.flags & TPM_BUF_OVERFLOW) {
137 rc = -E2BIG;
138 goto out;
139 }
140
141 rc = tpm_transmit_cmd(chip, &buf, 4, "sealing data");
142 if (rc)
143 goto out;
144
145 blob_len = be32_to_cpup((__be32 *) &buf.data[TPM_HEADER_SIZE]);
146 if (blob_len > MAX_BLOB_SIZE) {
147 rc = -E2BIG;
148 goto out;
149 }
150 if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 4 + blob_len) {
151 rc = -EFAULT;
152 goto out;
153 }
154
155 memcpy(payload->blob, &buf.data[TPM_HEADER_SIZE + 4], blob_len);
156 payload->blob_len = blob_len;
157
158 out:
159 tpm_buf_destroy(&buf);
160
161 if (rc > 0) {
162 if (tpm2_rc_value(rc) == TPM2_RC_HASH)
163 rc = -EINVAL;
164 else
165 rc = -EPERM;
166 }
167
168 tpm_put_ops(chip);
169 return rc;
170 }
171
172 /**
173 * tpm2_load_cmd() - execute a TPM2_Load command
174 *
175 * @chip: TPM chip to use
176 * @payload: the key data in clear and encrypted form
177 * @options: authentication values and other options
178 * @blob_handle: returned blob handle
179 *
180 * Return: 0 on success.
181 * -E2BIG on wrong payload size.
182 * -EPERM on tpm error status.
183 * < 0 error from tpm_send.
184 */
tpm2_load_cmd(struct tpm_chip * chip,struct trusted_key_payload * payload,struct trusted_key_options * options,u32 * blob_handle)185 static int tpm2_load_cmd(struct tpm_chip *chip,
186 struct trusted_key_payload *payload,
187 struct trusted_key_options *options,
188 u32 *blob_handle)
189 {
190 struct tpm_buf buf;
191 unsigned int private_len;
192 unsigned int public_len;
193 unsigned int blob_len;
194 int rc;
195
196 private_len = be16_to_cpup((__be16 *) &payload->blob[0]);
197 if (private_len > (payload->blob_len - 2))
198 return -E2BIG;
199
200 public_len = be16_to_cpup((__be16 *) &payload->blob[2 + private_len]);
201 blob_len = private_len + public_len + 4;
202 if (blob_len > payload->blob_len)
203 return -E2BIG;
204
205 rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
206 if (rc)
207 return rc;
208
209 tpm_buf_append_u32(&buf, options->keyhandle);
210 tpm2_buf_append_auth(&buf, TPM2_RS_PW,
211 NULL /* nonce */, 0,
212 0 /* session_attributes */,
213 options->keyauth /* hmac */,
214 TPM_DIGEST_SIZE);
215
216 tpm_buf_append(&buf, payload->blob, blob_len);
217
218 if (buf.flags & TPM_BUF_OVERFLOW) {
219 rc = -E2BIG;
220 goto out;
221 }
222
223 rc = tpm_transmit_cmd(chip, &buf, 4, "loading blob");
224 if (!rc)
225 *blob_handle = be32_to_cpup(
226 (__be32 *) &buf.data[TPM_HEADER_SIZE]);
227
228 out:
229 tpm_buf_destroy(&buf);
230
231 if (rc > 0)
232 rc = -EPERM;
233
234 return rc;
235 }
236
237 /**
238 * tpm2_unseal_cmd() - execute a TPM2_Unload command
239 *
240 * @chip: TPM chip to use
241 * @payload: the key data in clear and encrypted form
242 * @options: authentication values and other options
243 * @blob_handle: blob handle
244 *
245 * Return: 0 on success
246 * -EPERM on tpm error status
247 * < 0 error from tpm_send
248 */
tpm2_unseal_cmd(struct tpm_chip * chip,struct trusted_key_payload * payload,struct trusted_key_options * options,u32 blob_handle)249 static int tpm2_unseal_cmd(struct tpm_chip *chip,
250 struct trusted_key_payload *payload,
251 struct trusted_key_options *options,
252 u32 blob_handle)
253 {
254 struct tpm_buf buf;
255 u16 data_len;
256 u8 *data;
257 int rc;
258
259 rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
260 if (rc)
261 return rc;
262
263 tpm_buf_append_u32(&buf, blob_handle);
264 tpm2_buf_append_auth(&buf,
265 options->policyhandle ?
266 options->policyhandle : TPM2_RS_PW,
267 NULL /* nonce */, 0,
268 TPM2_SA_CONTINUE_SESSION,
269 options->blobauth /* hmac */,
270 options->blobauth_len);
271
272 rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing");
273 if (rc > 0)
274 rc = -EPERM;
275
276 if (!rc) {
277 data_len = be16_to_cpup(
278 (__be16 *) &buf.data[TPM_HEADER_SIZE + 4]);
279 if (data_len < MIN_KEY_SIZE || data_len > MAX_KEY_SIZE + 1) {
280 rc = -EFAULT;
281 goto out;
282 }
283
284 if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 6 + data_len) {
285 rc = -EFAULT;
286 goto out;
287 }
288 data = &buf.data[TPM_HEADER_SIZE + 6];
289
290 memcpy(payload->key, data, data_len - 1);
291 payload->key_len = data_len - 1;
292 payload->migratable = data[data_len - 1];
293 }
294
295 out:
296 tpm_buf_destroy(&buf);
297 return rc;
298 }
299
300 /**
301 * tpm2_unseal_trusted() - unseal the payload of a trusted key
302 *
303 * @chip: TPM chip to use
304 * @payload: the key data in clear and encrypted form
305 * @options: authentication values and other options
306 *
307 * Return: Same as with tpm_send.
308 */
tpm2_unseal_trusted(struct tpm_chip * chip,struct trusted_key_payload * payload,struct trusted_key_options * options)309 int tpm2_unseal_trusted(struct tpm_chip *chip,
310 struct trusted_key_payload *payload,
311 struct trusted_key_options *options)
312 {
313 u32 blob_handle;
314 int rc;
315
316 rc = tpm_try_get_ops(chip);
317 if (rc)
318 return rc;
319
320 rc = tpm2_load_cmd(chip, payload, options, &blob_handle);
321 if (rc)
322 goto out;
323
324 rc = tpm2_unseal_cmd(chip, payload, options, blob_handle);
325 tpm2_flush_context(chip, blob_handle);
326
327 out:
328 tpm_put_ops(chip);
329
330 return rc;
331 }
332