1 /*
2 * Copyright 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #pragma once
18
19 #include <hardware/keymaster_defs.h>
20
21 #include <keymaster/authorization_set.h>
22 #include <keymaster/km_version.h>
23
24 #include <cppbor.h>
25 #include <openssl/asn1t.h>
26
27 #include <vector>
28
29 #define remove_type_mask(tag) ((tag)&0x0FFFFFFF)
30
31 namespace keymaster {
32
33 class AttestationContext;
34
35 constexpr KmVersion kCurrentKmVersion = KmVersion::KEYMASTER_4_1;
36
37 // Size (in bytes) of generated UNIQUE_ID values.
38 constexpr int UNIQUE_ID_SIZE = 16;
39
40 constexpr int EAT_CLAIM_PRIVATE_BASE = -80000;
41 constexpr int EAT_CLAIM_PRIVATE_NON_KM_BASE = EAT_CLAIM_PRIVATE_BASE - 2000;
42
convert_to_eat_claim(keymaster_tag_t tag)43 constexpr int64_t convert_to_eat_claim(keymaster_tag_t tag) {
44 return EAT_CLAIM_PRIVATE_BASE - remove_type_mask(tag);
45 }
46
47 struct stack_st_ASN1_TYPE_Delete {
operatorstack_st_ASN1_TYPE_Delete48 void operator()(stack_st_ASN1_TYPE* p) { sk_ASN1_TYPE_free(p); }
49 };
50
51 struct ASN1_STRING_Delete {
operatorASN1_STRING_Delete52 void operator()(ASN1_STRING* p) { ASN1_STRING_free(p); }
53 };
54
55 struct ASN1_TYPE_Delete {
operatorASN1_TYPE_Delete56 void operator()(ASN1_TYPE* p) { ASN1_TYPE_free(p); }
57 };
58
59 #define ASN1_INTEGER_SET STACK_OF(ASN1_INTEGER)
60
61 typedef struct km_root_of_trust {
62 ASN1_OCTET_STRING* verified_boot_key;
63 ASN1_BOOLEAN device_locked;
64 ASN1_ENUMERATED* verified_boot_state;
65 ASN1_OCTET_STRING* verified_boot_hash;
66 } KM_ROOT_OF_TRUST;
67
68 ASN1_SEQUENCE(KM_ROOT_OF_TRUST) = {
69 ASN1_SIMPLE(KM_ROOT_OF_TRUST, verified_boot_key, ASN1_OCTET_STRING),
70 ASN1_SIMPLE(KM_ROOT_OF_TRUST, device_locked, ASN1_BOOLEAN),
71 ASN1_SIMPLE(KM_ROOT_OF_TRUST, verified_boot_state, ASN1_ENUMERATED),
72 ASN1_SIMPLE(KM_ROOT_OF_TRUST, verified_boot_hash, ASN1_OCTET_STRING),
73 } ASN1_SEQUENCE_END(KM_ROOT_OF_TRUST);
74 DECLARE_ASN1_FUNCTIONS(KM_ROOT_OF_TRUST);
75
76 // Fields ordered in tag order.
77 typedef struct km_auth_list {
78 ASN1_INTEGER_SET* purpose;
79 ASN1_INTEGER* algorithm;
80 ASN1_INTEGER* key_size;
81 ASN1_INTEGER_SET* block_mode;
82 ASN1_INTEGER_SET* digest;
83 ASN1_INTEGER_SET* padding;
84 ASN1_NULL* caller_nonce;
85 ASN1_INTEGER* min_mac_length;
86 ASN1_INTEGER_SET* kdf;
87 ASN1_INTEGER* ec_curve;
88 ASN1_INTEGER* rsa_public_exponent;
89 ASN1_INTEGER_SET* mgf_digest;
90 ASN1_NULL* rollback_resistance;
91 ASN1_NULL* early_boot_only;
92 ASN1_INTEGER* active_date_time;
93 ASN1_INTEGER* origination_expire_date_time;
94 ASN1_INTEGER* usage_expire_date_time;
95 ASN1_INTEGER* usage_count_limit;
96 ASN1_NULL* no_auth_required;
97 ASN1_INTEGER* user_auth_type;
98 ASN1_INTEGER* auth_timeout;
99 ASN1_NULL* allow_while_on_body;
100 ASN1_NULL* trusted_user_presence_required;
101 ASN1_NULL* trusted_confirmation_required;
102 ASN1_NULL* unlocked_device_required;
103 ASN1_NULL* all_applications;
104 ASN1_OCTET_STRING* application_id;
105 ASN1_INTEGER* creation_date_time;
106 ASN1_INTEGER* origin;
107 ASN1_NULL* rollback_resistant;
108 KM_ROOT_OF_TRUST* root_of_trust;
109 ASN1_INTEGER* os_version;
110 ASN1_INTEGER* os_patchlevel;
111 ASN1_OCTET_STRING* attestation_application_id;
112 ASN1_OCTET_STRING* attestation_id_brand;
113 ASN1_OCTET_STRING* attestation_id_device;
114 ASN1_OCTET_STRING* attestation_id_product;
115 ASN1_OCTET_STRING* attestation_id_serial;
116 ASN1_OCTET_STRING* attestation_id_imei;
117 ASN1_OCTET_STRING* attestation_id_meid;
118 ASN1_OCTET_STRING* attestation_id_manufacturer;
119 ASN1_OCTET_STRING* attestation_id_model;
120 ASN1_INTEGER* vendor_patchlevel;
121 ASN1_INTEGER* boot_patch_level;
122 ASN1_NULL* device_unique_attestation;
123 ASN1_NULL* identity_credential_key;
124 ASN1_OCTET_STRING* attestation_id_second_imei;
125 ASN1_OCTET_STRING* module_hash;
126 } KM_AUTH_LIST;
127
128 ASN1_SEQUENCE(KM_AUTH_LIST) = {
129 ASN1_EXP_SET_OF_OPT(KM_AUTH_LIST, purpose, ASN1_INTEGER, TAG_PURPOSE.masked_tag()),
130 ASN1_EXP_OPT(KM_AUTH_LIST, algorithm, ASN1_INTEGER, TAG_ALGORITHM.masked_tag()),
131 ASN1_EXP_OPT(KM_AUTH_LIST, key_size, ASN1_INTEGER, TAG_KEY_SIZE.masked_tag()),
132 ASN1_EXP_SET_OF_OPT(KM_AUTH_LIST, block_mode, ASN1_INTEGER, TAG_BLOCK_MODE.masked_tag()),
133 ASN1_EXP_SET_OF_OPT(KM_AUTH_LIST, digest, ASN1_INTEGER, TAG_DIGEST.masked_tag()),
134 ASN1_EXP_SET_OF_OPT(KM_AUTH_LIST, padding, ASN1_INTEGER, TAG_PADDING.masked_tag()),
135 ASN1_EXP_OPT(KM_AUTH_LIST, caller_nonce, ASN1_NULL, TAG_CALLER_NONCE.masked_tag()),
136 ASN1_EXP_OPT(KM_AUTH_LIST, min_mac_length, ASN1_INTEGER, TAG_MIN_MAC_LENGTH.masked_tag()),
137 ASN1_EXP_SET_OF_OPT(KM_AUTH_LIST, kdf, ASN1_INTEGER, TAG_KDF.masked_tag()),
138 ASN1_EXP_OPT(KM_AUTH_LIST, ec_curve, ASN1_INTEGER, TAG_EC_CURVE.masked_tag()),
139 ASN1_EXP_OPT(KM_AUTH_LIST, rsa_public_exponent, ASN1_INTEGER,
140 TAG_RSA_PUBLIC_EXPONENT.masked_tag()),
141 ASN1_EXP_SET_OF_OPT(KM_AUTH_LIST, mgf_digest, ASN1_INTEGER,
142 TAG_RSA_OAEP_MGF_DIGEST.masked_tag()),
143 ASN1_EXP_OPT(KM_AUTH_LIST, rollback_resistance, ASN1_NULL,
144 TAG_ROLLBACK_RESISTANCE.masked_tag()),
145 ASN1_EXP_OPT(KM_AUTH_LIST, early_boot_only, ASN1_NULL, TAG_EARLY_BOOT_ONLY.masked_tag()),
146 ASN1_EXP_OPT(KM_AUTH_LIST, active_date_time, ASN1_INTEGER, TAG_ACTIVE_DATETIME.masked_tag()),
147 ASN1_EXP_OPT(KM_AUTH_LIST, origination_expire_date_time, ASN1_INTEGER,
148 TAG_ORIGINATION_EXPIRE_DATETIME.masked_tag()),
149 ASN1_EXP_OPT(KM_AUTH_LIST, usage_expire_date_time, ASN1_INTEGER,
150 TAG_USAGE_EXPIRE_DATETIME.masked_tag()),
151 ASN1_EXP_OPT(KM_AUTH_LIST, usage_count_limit, ASN1_INTEGER, TAG_USAGE_COUNT_LIMIT.masked_tag()),
152 ASN1_EXP_OPT(KM_AUTH_LIST, no_auth_required, ASN1_NULL, TAG_NO_AUTH_REQUIRED.masked_tag()),
153 ASN1_EXP_OPT(KM_AUTH_LIST, user_auth_type, ASN1_INTEGER, TAG_USER_AUTH_TYPE.masked_tag()),
154 ASN1_EXP_OPT(KM_AUTH_LIST, auth_timeout, ASN1_INTEGER, TAG_AUTH_TIMEOUT.masked_tag()),
155 ASN1_EXP_OPT(KM_AUTH_LIST, allow_while_on_body, ASN1_NULL,
156 TAG_ALLOW_WHILE_ON_BODY.masked_tag()),
157 ASN1_EXP_OPT(KM_AUTH_LIST, trusted_user_presence_required, ASN1_NULL,
158 TAG_TRUSTED_USER_PRESENCE_REQUIRED.masked_tag()),
159 ASN1_EXP_OPT(KM_AUTH_LIST, trusted_confirmation_required, ASN1_NULL,
160 TAG_TRUSTED_CONFIRMATION_REQUIRED.masked_tag()),
161 ASN1_EXP_OPT(KM_AUTH_LIST, unlocked_device_required, ASN1_NULL,
162 TAG_UNLOCKED_DEVICE_REQUIRED.masked_tag()),
163 ASN1_EXP_OPT(KM_AUTH_LIST, all_applications, ASN1_NULL, TAG_ALL_APPLICATIONS.masked_tag()),
164 ASN1_EXP_OPT(KM_AUTH_LIST, application_id, ASN1_OCTET_STRING, TAG_APPLICATION_ID.masked_tag()),
165 ASN1_EXP_OPT(KM_AUTH_LIST, creation_date_time, ASN1_INTEGER,
166 TAG_CREATION_DATETIME.masked_tag()),
167 ASN1_EXP_OPT(KM_AUTH_LIST, origin, ASN1_INTEGER, TAG_ORIGIN.masked_tag()),
168 ASN1_EXP_OPT(KM_AUTH_LIST, rollback_resistant, ASN1_NULL, TAG_ROLLBACK_RESISTANT.masked_tag()),
169 ASN1_EXP_OPT(KM_AUTH_LIST, root_of_trust, KM_ROOT_OF_TRUST, TAG_ROOT_OF_TRUST.masked_tag()),
170 ASN1_EXP_OPT(KM_AUTH_LIST, os_version, ASN1_INTEGER, TAG_OS_VERSION.masked_tag()),
171 ASN1_EXP_OPT(KM_AUTH_LIST, os_patchlevel, ASN1_INTEGER, TAG_OS_PATCHLEVEL.masked_tag()),
172 ASN1_EXP_OPT(KM_AUTH_LIST, attestation_application_id, ASN1_OCTET_STRING,
173 TAG_ATTESTATION_APPLICATION_ID.masked_tag()),
174 ASN1_EXP_OPT(KM_AUTH_LIST, attestation_id_brand, ASN1_OCTET_STRING,
175 TAG_ATTESTATION_ID_BRAND.masked_tag()),
176 ASN1_EXP_OPT(KM_AUTH_LIST, attestation_id_device, ASN1_OCTET_STRING,
177 TAG_ATTESTATION_ID_DEVICE.masked_tag()),
178 ASN1_EXP_OPT(KM_AUTH_LIST, attestation_id_product, ASN1_OCTET_STRING,
179 TAG_ATTESTATION_ID_PRODUCT.masked_tag()),
180 ASN1_EXP_OPT(KM_AUTH_LIST, attestation_id_serial, ASN1_OCTET_STRING,
181 TAG_ATTESTATION_ID_SERIAL.masked_tag()),
182 ASN1_EXP_OPT(KM_AUTH_LIST, attestation_id_imei, ASN1_OCTET_STRING,
183 TAG_ATTESTATION_ID_IMEI.masked_tag()),
184 ASN1_EXP_OPT(KM_AUTH_LIST, attestation_id_meid, ASN1_OCTET_STRING,
185 TAG_ATTESTATION_ID_MEID.masked_tag()),
186 ASN1_EXP_OPT(KM_AUTH_LIST, attestation_id_manufacturer, ASN1_OCTET_STRING,
187 TAG_ATTESTATION_ID_MANUFACTURER.masked_tag()),
188 ASN1_EXP_OPT(KM_AUTH_LIST, attestation_id_model, ASN1_OCTET_STRING,
189 TAG_ATTESTATION_ID_MODEL.masked_tag()),
190 ASN1_EXP_OPT(KM_AUTH_LIST, vendor_patchlevel, ASN1_INTEGER, TAG_VENDOR_PATCHLEVEL.masked_tag()),
191 ASN1_EXP_OPT(KM_AUTH_LIST, boot_patch_level, ASN1_INTEGER, TAG_BOOT_PATCHLEVEL.masked_tag()),
192 ASN1_EXP_OPT(KM_AUTH_LIST, device_unique_attestation, ASN1_NULL,
193 TAG_DEVICE_UNIQUE_ATTESTATION.masked_tag()),
194 ASN1_EXP_OPT(KM_AUTH_LIST, identity_credential_key, ASN1_NULL,
195 TAG_IDENTITY_CREDENTIAL_KEY.masked_tag()),
196 ASN1_EXP_OPT(KM_AUTH_LIST, attestation_id_second_imei, ASN1_OCTET_STRING,
197 TAG_ATTESTATION_ID_SECOND_IMEI.masked_tag()),
198 ASN1_EXP_OPT(KM_AUTH_LIST, module_hash, ASN1_OCTET_STRING, TAG_MODULE_HASH.masked_tag()),
199 } ASN1_SEQUENCE_END(KM_AUTH_LIST);
200 DECLARE_ASN1_FUNCTIONS(KM_AUTH_LIST);
201
202 typedef struct km_key_description {
203 ASN1_INTEGER* attestation_version;
204 ASN1_ENUMERATED* attestation_security_level;
205 ASN1_INTEGER* keymaster_version;
206 ASN1_ENUMERATED* keymaster_security_level;
207 ASN1_OCTET_STRING* attestation_challenge;
208 KM_AUTH_LIST* software_enforced;
209 KM_AUTH_LIST* tee_enforced;
210 ASN1_OCTET_STRING* unique_id;
211 } KM_KEY_DESCRIPTION;
212
213 ASN1_SEQUENCE(KM_KEY_DESCRIPTION) = {
214 ASN1_SIMPLE(KM_KEY_DESCRIPTION, attestation_version, ASN1_INTEGER),
215 ASN1_SIMPLE(KM_KEY_DESCRIPTION, attestation_security_level, ASN1_ENUMERATED),
216 ASN1_SIMPLE(KM_KEY_DESCRIPTION, keymaster_version, ASN1_INTEGER),
217 ASN1_SIMPLE(KM_KEY_DESCRIPTION, keymaster_security_level, ASN1_ENUMERATED),
218 ASN1_SIMPLE(KM_KEY_DESCRIPTION, attestation_challenge, ASN1_OCTET_STRING),
219 ASN1_SIMPLE(KM_KEY_DESCRIPTION, unique_id, ASN1_OCTET_STRING),
220 ASN1_SIMPLE(KM_KEY_DESCRIPTION, software_enforced, KM_AUTH_LIST),
221 ASN1_SIMPLE(KM_KEY_DESCRIPTION, tee_enforced, KM_AUTH_LIST),
222 } ASN1_SEQUENCE_END(KM_KEY_DESCRIPTION);
223 DECLARE_ASN1_FUNCTIONS(KM_KEY_DESCRIPTION);
224
225 enum class EatClaim {
226
227 // Official CWT claims, as defined in https://www.iana.org/assignments/cwt/cwt.xhtml
228
229 IAT = 6,
230 CTI = 7,
231
232 // Claims defined in
233 // https://github.com/laurencelundblade/ctoken/blob/master/inc/ctoken_eat_labels.h, by the
234 // author of the EAT standard, and in the ARM PSA. They should be considered stable at least
235 // until the standard is officially published.
236
237 UEID = -75009,
238 NONCE = -75008,
239 SECURITY_LEVEL = -76002,
240 BOOT_STATE = -76003,
241 SUBMODS = -76000,
242
243 // Claims specific to Android, and not part of the official EAT standard.
244
245 PURPOSE = convert_to_eat_claim(KM_TAG_PURPOSE),
246 ALGORITHM = convert_to_eat_claim(KM_TAG_ALGORITHM),
247 KEY_SIZE = convert_to_eat_claim(KM_TAG_KEY_SIZE),
248 BLOCK_MODE = convert_to_eat_claim(KM_TAG_BLOCK_MODE),
249 DIGEST = convert_to_eat_claim(KM_TAG_DIGEST),
250 PADDING = convert_to_eat_claim(KM_TAG_PADDING),
251 // TODO: Check if CALLER_NONCE is needed (see go/keymint-eat)
252 CALLER_NONCE = convert_to_eat_claim(KM_TAG_CALLER_NONCE),
253 MIN_MAC_LENGTH = convert_to_eat_claim(KM_TAG_MIN_MAC_LENGTH),
254 EC_CURVE = convert_to_eat_claim(KM_TAG_EC_CURVE),
255 RSA_PUBLIC_EXPONENT = convert_to_eat_claim(KM_TAG_RSA_PUBLIC_EXPONENT),
256 EARLY_BOOT_ONLY = convert_to_eat_claim(KM_TAG_EARLY_BOOT_ONLY),
257 ACTIVE_DATETIME = convert_to_eat_claim(KM_TAG_ACTIVE_DATETIME),
258 ORIGINATION_EXPIRE_DATETIME = convert_to_eat_claim(KM_TAG_ORIGINATION_EXPIRE_DATETIME),
259 USAGE_EXPIRE_DATETIME = convert_to_eat_claim(KM_TAG_USAGE_EXPIRE_DATETIME),
260 NO_AUTH_REQUIRED = convert_to_eat_claim(KM_TAG_NO_AUTH_REQUIRED),
261 USER_AUTH_TYPE = convert_to_eat_claim(KM_TAG_USER_AUTH_TYPE),
262 AUTH_TIMEOUT = convert_to_eat_claim(KM_TAG_AUTH_TIMEOUT),
263 ALLOW_WHILE_ON_BODY = convert_to_eat_claim(KM_TAG_ALLOW_WHILE_ON_BODY),
264 TRUSTED_USER_PRESENCE_REQUIRED = convert_to_eat_claim(KM_TAG_TRUSTED_USER_PRESENCE_REQUIRED),
265 TRUSTED_CONFIRMATION_REQUIRED = convert_to_eat_claim(KM_TAG_TRUSTED_CONFIRMATION_REQUIRED),
266 UNLOCKED_DEVICE_REQUIRED = convert_to_eat_claim(KM_TAG_UNLOCKED_DEVICE_REQUIRED),
267 ALL_APPLICATIONS = convert_to_eat_claim(KM_TAG_ALL_APPLICATIONS),
268 APPLICATION_ID = convert_to_eat_claim(KM_TAG_APPLICATION_ID),
269 ORIGIN = convert_to_eat_claim(KM_TAG_ORIGIN),
270 ROLLBACK_RESISTANT = convert_to_eat_claim(KM_TAG_ROLLBACK_RESISTANT),
271 OS_VERSION = convert_to_eat_claim(KM_TAG_OS_VERSION),
272 OS_PATCHLEVEL = convert_to_eat_claim(KM_TAG_OS_PATCHLEVEL),
273 ATTESTATION_APPLICATION_ID = convert_to_eat_claim(KM_TAG_ATTESTATION_APPLICATION_ID),
274 ATTESTATION_ID_BRAND = convert_to_eat_claim(KM_TAG_ATTESTATION_ID_BRAND),
275 ATTESTATION_ID_DEVICE = convert_to_eat_claim(KM_TAG_ATTESTATION_ID_DEVICE),
276 ATTESTATION_ID_PRODUCT = convert_to_eat_claim(KM_TAG_ATTESTATION_ID_PRODUCT),
277 ATTESTATION_ID_SERIAL = convert_to_eat_claim(KM_TAG_ATTESTATION_ID_SERIAL),
278 ATTESTATION_ID_MEID = convert_to_eat_claim(KM_TAG_ATTESTATION_ID_MEID),
279 ATTESTATION_ID_MANUFACTURER = convert_to_eat_claim(KM_TAG_ATTESTATION_ID_MANUFACTURER),
280 VENDOR_PATCHLEVEL = convert_to_eat_claim(KM_TAG_VENDOR_PATCHLEVEL),
281 BOOT_PATCHLEVEL = convert_to_eat_claim(KM_TAG_BOOT_PATCHLEVEL),
282 ATTESTATION_ID_MODEL = convert_to_eat_claim(KM_TAG_ATTESTATION_ID_MODEL),
283 DEVICE_UNIQUE_ATTESTATION = convert_to_eat_claim(KM_TAG_DEVICE_UNIQUE_ATTESTATION),
284 IDENTITY_CREDENTIAL_KEY = convert_to_eat_claim(KM_TAG_IDENTITY_CREDENTIAL_KEY),
285 STORAGE_KEY = convert_to_eat_claim(KM_TAG_STORAGE_KEY),
286 CONFIRMATION_TOKEN = convert_to_eat_claim(KM_TAG_CONFIRMATION_TOKEN),
287
288 // Claims specific to Android that do not exist as Keymint tags.
289
290 VERIFIED_BOOT_KEY = EAT_CLAIM_PRIVATE_NON_KM_BASE - 1,
291 DEVICE_LOCKED = EAT_CLAIM_PRIVATE_NON_KM_BASE - 2,
292 VERIFIED_BOOT_HASH = EAT_CLAIM_PRIVATE_NON_KM_BASE - 3,
293 ATTESTATION_VERSION = EAT_CLAIM_PRIVATE_NON_KM_BASE - 4,
294 KEYMASTER_VERSION = EAT_CLAIM_PRIVATE_NON_KM_BASE - 5,
295 OFFICIAL_BUILD = EAT_CLAIM_PRIVATE_NON_KM_BASE - 6,
296 };
297
298 enum class EatSecurityLevel {
299 UNRESTRICTED = 1,
300 RESTRICTED = 2,
301 SECURE_RESTRICTED = 3,
302 HARDWARE = 4,
303 };
304
305 enum class EatEcCurve {
306 P_224 = KM_EC_CURVE_P_224,
307 P_256 = KM_EC_CURVE_P_256,
308 P_384 = KM_EC_CURVE_P_384,
309 P_521 = KM_EC_CURVE_P_521,
310 };
311
312 static const char kEatSubmodNameSoftware[] = "software";
313 static const char kEatSubmodNameTee[] = "tee";
314
315 constexpr size_t kImeiBlobLength = 15;
316 constexpr size_t kUeidLength = 15;
317 constexpr uint8_t kImeiTypeByte = 0x03;
318
319 /**
320 * The OID for Android attestation records. For the curious, it breaks down as follows:
321 *
322 * 1 = ISO
323 * 3 = org
324 * 6 = DoD (Huh? OIDs are weird.)
325 * 1 = IANA
326 * 4 = Private
327 * 1 = Enterprises
328 * 11129 = Google
329 * 2 = Google security
330 * 1 = certificate extension
331 * 17 / 25 = ASN.1 attestation extension / EAT attestation extension
332 */
333 static const char kAsn1TokenOid[] = "1.3.6.1.4.1.11129.2.1.17";
334 static const char kEatTokenOid[] = "1.3.6.1.4.1.11129.2.1.25";
335
336 // This build_attestation_record sets the keymaster version to the default
337 // value, and chooses the correct attestation extension (ASN.1 or EAT) based
338 // on that value.
339 keymaster_error_t build_attestation_record(const AuthorizationSet& attestation_params,
340 AuthorizationSet software_enforced,
341 AuthorizationSet tee_enforced,
342 const AttestationContext& context,
343 UniquePtr<uint8_t[]>* asn1_key_desc,
344 size_t* asn1_key_desc_len);
345
346 // Builds EAT record, with the same values as the attestation record above,
347 // but encoded as a CBOR (EAT) structure rather than an ASN.1 structure.
348 keymaster_error_t build_eat_record(const AuthorizationSet& attestation_params,
349 AuthorizationSet software_enforced,
350 AuthorizationSet tee_enforced, //
351 const AttestationContext& context, //
352 std::vector<uint8_t>* eat_token);
353
354 // Builds the input to HMAC-SHA256 for unique ID generation.
355 keymaster_error_t build_unique_id_input(uint64_t creation_date_time,
356 const keymaster_blob_t& application_id,
357 bool reset_since_rotation, Buffer* input_data);
358
359 // Builds a unique ID of size UNIQUE_ID_SIZE from the given inputs.
360 keymaster_error_t generate_unique_id(const std::vector<uint8_t>& hbk, uint64_t creation_date_time,
361 const keymaster_blob_t& application_id,
362 bool reset_since_rotation, Buffer* unique_id);
363
364 /**
365 * Helper functions for attestation record tests. Caller takes ownership of
366 * |attestation_challenge->data| and |unique_id->data|, deallocate using delete[].
367 */
368 keymaster_error_t parse_attestation_record(const uint8_t* asn1_key_desc, size_t asn1_key_desc_len,
369 uint32_t* attestation_version, //
370 keymaster_security_level_t* attestation_security_level,
371 uint32_t* keymaster_version,
372 keymaster_security_level_t* keymaster_security_level,
373 keymaster_blob_t* attestation_challenge,
374 AuthorizationSet* software_enforced,
375 AuthorizationSet* tee_enforced,
376 keymaster_blob_t* unique_id);
377
378 /**
379 * Caller takes ownership of |verified_boot_key->data|, deallocate using delete[].
380 */
381 keymaster_error_t parse_root_of_trust(const uint8_t* asn1_key_desc, size_t asn1_key_desc_len,
382 keymaster_blob_t* verified_boot_key,
383 keymaster_verified_boot_t* verified_boot_state,
384 bool* device_locked);
385
386 keymaster_error_t build_eat_submod(const AuthorizationSet& auth_list,
387 EatSecurityLevel security_level, cppbor::Map* submod);
388
389 keymaster_error_t build_auth_list(const AuthorizationSet& auth_list, KM_AUTH_LIST* record);
390
391 keymaster_error_t parse_eat_record(
392 const uint8_t* eat_key_desc, size_t eat_key_desc_len, uint32_t* attestation_version,
393 keymaster_security_level_t* attestation_security_level, uint32_t* keymaster_version,
394 keymaster_security_level_t* keymaster_security_level, keymaster_blob_t* attestation_challenge,
395 AuthorizationSet* software_enforced, AuthorizationSet* tee_enforced,
396 keymaster_blob_t* unique_id, keymaster_blob_t* verified_boot_key,
397 keymaster_verified_boot_t* verified_boot_state, bool* device_locked,
398 std::vector<int64_t>* unexpected_claims);
399
400 keymaster_error_t parse_eat_submod(const cppbor::Map* submod_values,
401 AuthorizationSet* software_enforced,
402 AuthorizationSet* tee_enforced);
403
404 keymaster_error_t extract_auth_list(const KM_AUTH_LIST* record, AuthorizationSet* auth_list);
405
406 /**
407 * Convert a KeymasterContext::Version to the keymaster version number used in attestations.
408 */
version_to_attestation_km_version(KmVersion version)409 inline static uint32_t version_to_attestation_km_version(KmVersion version) {
410 switch (version) {
411 default:
412 case KmVersion::KEYMASTER_1:
413 case KmVersion::KEYMASTER_1_1:
414 return 0; // Attestation not actually supported.
415 case KmVersion::KEYMASTER_2:
416 return 2;
417 case KmVersion::KEYMASTER_3:
418 return 3;
419 case KmVersion::KEYMASTER_4:
420 return 4;
421 case KmVersion::KEYMASTER_4_1:
422 return 41;
423 case KmVersion::KEYMINT_1:
424 return 100;
425 case KmVersion::KEYMINT_2:
426 return 200;
427 case KmVersion::KEYMINT_3:
428 return 300;
429 case KmVersion::KEYMINT_4:
430 return 400;
431 }
432 }
433
434 /**
435 * Convert a KeymasterContext::Version to the corresponding attestation format version number.
436 */
version_to_attestation_version(KmVersion version)437 inline static uint32_t version_to_attestation_version(KmVersion version) {
438 switch (version) {
439 default:
440 case KmVersion::KEYMASTER_1:
441 return 0; // Attestation not actually supported.
442 case KmVersion::KEYMASTER_2:
443 return 1;
444 case KmVersion::KEYMASTER_3:
445 return 2;
446 case KmVersion::KEYMASTER_4:
447 return 3;
448 case KmVersion::KEYMASTER_4_1:
449 return 4;
450 case KmVersion::KEYMINT_1:
451 return 100;
452 case KmVersion::KEYMINT_2:
453 return 200;
454 case KmVersion::KEYMINT_3:
455 return 300;
456 case KmVersion::KEYMINT_4:
457 return 400;
458 }
459 }
460
461 } // namespace keymaster
462