1 /*
2 * Copyright 2015 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 #include <keymaster/legacy_support/keymaster1_engine.h>
18
19 #include <assert.h>
20
21 #include <algorithm>
22 #include <memory>
23
24 #define LOG_TAG "Keymaster1Engine"
25 #include <log/log.h>
26
27 #include <keymaster/android_keymaster_utils.h>
28 #include <keymaster/km_openssl/openssl_err.h>
29 #include <keymaster/km_openssl/openssl_utils.h>
30
31 #include <openssl/bn.h>
32 #include <openssl/ec_key.h>
33 #include <openssl/ecdsa.h>
34
35 using std::unique_ptr;
36
37 namespace keymaster {
38
39 Keymaster1Engine* Keymaster1Engine::instance_ = nullptr;
40
Keymaster1Engine(const keymaster1_device_t * keymaster1_device)41 Keymaster1Engine::Keymaster1Engine(const keymaster1_device_t* keymaster1_device)
42 : keymaster1_device_(keymaster1_device), engine_(ENGINE_new()),
43 rsa_index_(RSA_get_ex_new_index(0 /* argl */, nullptr /* argp */, nullptr /* new_func */,
44 Keymaster1Engine::duplicate_key_data,
45 Keymaster1Engine::free_key_data)),
46 ec_key_index_(EC_KEY_get_ex_new_index(
47 0 /* argl */, nullptr /* argp */, nullptr /* new_func */,
48 Keymaster1Engine::duplicate_key_data, Keymaster1Engine::free_key_data)),
49 rsa_method_(BuildRsaMethod()), ecdsa_method_(BuildEcdsaMethod()) {
50 assert(rsa_index_ != -1);
51 assert(ec_key_index_ != -1);
52 assert(keymaster1_device);
53 assert(!instance_);
54
55 instance_ = this;
56
57 ENGINE_set_RSA_method(engine_.get(), &rsa_method_, sizeof(rsa_method_));
58 ENGINE_set_ECDSA_method(engine_.get(), &ecdsa_method_, sizeof(ecdsa_method_));
59 }
60
~Keymaster1Engine()61 Keymaster1Engine::~Keymaster1Engine() {
62 keymaster1_device_->common.close(
63 reinterpret_cast<hw_device_t*>(const_cast<keymaster1_device_t*>(keymaster1_device_)));
64 instance_ = nullptr;
65 }
66
ConvertCharacteristics(keymaster_key_characteristics_t * characteristics,AuthorizationSet * hw_enforced,AuthorizationSet * sw_enforced)67 static void ConvertCharacteristics(keymaster_key_characteristics_t* characteristics,
68 AuthorizationSet* hw_enforced, AuthorizationSet* sw_enforced) {
69 unique_ptr<keymaster_key_characteristics_t, Characteristics_Delete> characteristics_deleter(
70 characteristics);
71 if (hw_enforced) hw_enforced->Reinitialize(characteristics->hw_enforced);
72 if (sw_enforced) sw_enforced->Reinitialize(characteristics->sw_enforced);
73 }
74
GenerateKey(const AuthorizationSet & key_description,KeymasterKeyBlob * key_blob,AuthorizationSet * hw_enforced,AuthorizationSet * sw_enforced) const75 keymaster_error_t Keymaster1Engine::GenerateKey(const AuthorizationSet& key_description,
76 KeymasterKeyBlob* key_blob,
77 AuthorizationSet* hw_enforced,
78 AuthorizationSet* sw_enforced) const {
79 assert(key_blob);
80
81 keymaster_key_characteristics_t* characteristics;
82 keymaster_key_blob_t blob;
83 keymaster_error_t error = keymaster1_device_->generate_key(keymaster1_device_, &key_description,
84 &blob, &characteristics);
85 if (error != KM_ERROR_OK) return error;
86 unique_ptr<uint8_t, Malloc_Delete> blob_deleter(const_cast<uint8_t*>(blob.key_material));
87 key_blob->key_material = dup_buffer(blob.key_material, blob.key_material_size);
88 key_blob->key_material_size = blob.key_material_size;
89
90 ConvertCharacteristics(characteristics, hw_enforced, sw_enforced);
91 return error;
92 }
93
ImportKey(const AuthorizationSet & key_description,keymaster_key_format_t input_key_material_format,const KeymasterKeyBlob & input_key_material,KeymasterKeyBlob * output_key_blob,AuthorizationSet * hw_enforced,AuthorizationSet * sw_enforced) const94 keymaster_error_t Keymaster1Engine::ImportKey(const AuthorizationSet& key_description,
95 keymaster_key_format_t input_key_material_format,
96 const KeymasterKeyBlob& input_key_material,
97 KeymasterKeyBlob* output_key_blob,
98 AuthorizationSet* hw_enforced,
99 AuthorizationSet* sw_enforced) const {
100 assert(output_key_blob);
101
102 keymaster_key_characteristics_t* characteristics;
103 const keymaster_blob_t input_key = {input_key_material.key_material,
104 input_key_material.key_material_size};
105 keymaster_key_blob_t blob;
106 keymaster_error_t error = keymaster1_device_->import_key(keymaster1_device_, &key_description,
107 input_key_material_format, &input_key,
108 &blob, &characteristics);
109 if (error != KM_ERROR_OK) return error;
110 unique_ptr<uint8_t, Malloc_Delete> blob_deleter(const_cast<uint8_t*>(blob.key_material));
111 output_key_blob->key_material = dup_buffer(blob.key_material, blob.key_material_size);
112 output_key_blob->key_material_size = blob.key_material_size;
113
114 ConvertCharacteristics(characteristics, hw_enforced, sw_enforced);
115 return error;
116 }
117
DeleteKey(const KeymasterKeyBlob & blob) const118 keymaster_error_t Keymaster1Engine::DeleteKey(const KeymasterKeyBlob& blob) const {
119 if (!keymaster1_device_->delete_key) return KM_ERROR_OK;
120 return keymaster1_device_->delete_key(keymaster1_device_, &blob);
121 }
122
DeleteAllKeys() const123 keymaster_error_t Keymaster1Engine::DeleteAllKeys() const {
124 if (!keymaster1_device_->delete_all_keys) return KM_ERROR_OK;
125 return keymaster1_device_->delete_all_keys(keymaster1_device_);
126 }
127
BuildRsaKey(const KeymasterKeyBlob & blob,const AuthorizationSet & additional_params,keymaster_error_t * error) const128 RSA* Keymaster1Engine::BuildRsaKey(const KeymasterKeyBlob& blob,
129 const AuthorizationSet& additional_params,
130 keymaster_error_t* error) const {
131 // Create new RSA key (with engine methods) and add metadata
132 unique_ptr<RSA, RSA_Delete> rsa(RSA_new_method(engine_.get()));
133 if (!rsa) {
134 *error = TranslateLastOpenSslError();
135 return nullptr;
136 }
137
138 KeyData* key_data = new KeyData(blob, additional_params);
139 if (!RSA_set_ex_data(rsa.get(), rsa_index_, key_data)) {
140 *error = TranslateLastOpenSslError();
141 delete key_data;
142 return nullptr;
143 }
144
145 // Copy public key into new RSA key
146 unique_ptr<EVP_PKEY, EVP_PKEY_Delete> pkey(
147 GetKeymaster1PublicKey(key_data->key_material, key_data->begin_params, error));
148 if (*error != KM_ERROR_OK) return nullptr;
149
150 unique_ptr<RSA, RSA_Delete> public_rsa(EVP_PKEY_get1_RSA(pkey.get()));
151 if (!public_rsa) {
152 *error = TranslateLastOpenSslError();
153 return nullptr;
154 }
155
156 rsa->n = BN_dup(public_rsa->n);
157 rsa->e = BN_dup(public_rsa->e);
158 if (!rsa->n || !rsa->e) {
159 *error = TranslateLastOpenSslError();
160 return nullptr;
161 }
162
163 *error = KM_ERROR_OK;
164 return rsa.release();
165 }
166
BuildEcKey(const KeymasterKeyBlob & blob,const AuthorizationSet & additional_params,keymaster_error_t * error) const167 EC_KEY* Keymaster1Engine::BuildEcKey(const KeymasterKeyBlob& blob,
168 const AuthorizationSet& additional_params,
169 keymaster_error_t* error) const {
170 // Create new EC key (with engine methods) and insert blob
171 unique_ptr<EC_KEY, EC_KEY_Delete> ec_key(EC_KEY_new_method(engine_.get()));
172 if (!ec_key) {
173 *error = TranslateLastOpenSslError();
174 return nullptr;
175 }
176
177 KeyData* key_data = new KeyData(blob, additional_params);
178 if (!EC_KEY_set_ex_data(ec_key.get(), ec_key_index_, key_data)) {
179 *error = TranslateLastOpenSslError();
180 delete key_data;
181 return nullptr;
182 }
183
184 // Copy public key into new EC key
185 unique_ptr<EVP_PKEY, EVP_PKEY_Delete> pkey(
186 GetKeymaster1PublicKey(blob, additional_params, error));
187 if (*error != KM_ERROR_OK) return nullptr;
188
189 unique_ptr<EC_KEY, EC_KEY_Delete> public_ec_key(EVP_PKEY_get1_EC_KEY(pkey.get()));
190 if (!public_ec_key) {
191 *error = TranslateLastOpenSslError();
192 return nullptr;
193 }
194
195 if (!EC_KEY_set_group(ec_key.get(), EC_KEY_get0_group(public_ec_key.get())) ||
196 !EC_KEY_set_public_key(ec_key.get(), EC_KEY_get0_public_key(public_ec_key.get()))) {
197 *error = TranslateLastOpenSslError();
198 return nullptr;
199 }
200
201 *error = KM_ERROR_OK;
202 return ec_key.release();
203 }
204
GetData(EVP_PKEY * key) const205 Keymaster1Engine::KeyData* Keymaster1Engine::GetData(EVP_PKEY* key) const {
206 switch (EVP_PKEY_type(key->type)) {
207 case EVP_PKEY_RSA: {
208 unique_ptr<RSA, RSA_Delete> rsa(EVP_PKEY_get1_RSA(key));
209 return GetData(rsa.get());
210 }
211
212 case EVP_PKEY_EC: {
213 unique_ptr<EC_KEY, EC_KEY_Delete> ec_key(EVP_PKEY_get1_EC_KEY(key));
214 return GetData(ec_key.get());
215 }
216
217 default:
218 return nullptr;
219 };
220 }
221
GetData(const RSA * rsa) const222 Keymaster1Engine::KeyData* Keymaster1Engine::GetData(const RSA* rsa) const {
223 if (!rsa) return nullptr;
224 return reinterpret_cast<KeyData*>(RSA_get_ex_data(rsa, rsa_index_));
225 }
226
GetData(const EC_KEY * ec_key) const227 Keymaster1Engine::KeyData* Keymaster1Engine::GetData(const EC_KEY* ec_key) const {
228 if (!ec_key) return nullptr;
229 return reinterpret_cast<KeyData*>(EC_KEY_get_ex_data(ec_key, ec_key_index_));
230 }
231
232 /* static */
duplicate_key_data(CRYPTO_EX_DATA *,const CRYPTO_EX_DATA *,void ** from_d,int,long,void *)233 int Keymaster1Engine::duplicate_key_data(CRYPTO_EX_DATA* /* to */, const CRYPTO_EX_DATA* /* from */,
234 // NOLINTNEXTLINE(google-runtime-int)
235 void** from_d, int /* index */, long /* argl */,
236 void* /* argp */) {
237 KeyData* data = reinterpret_cast<KeyData*>(*from_d);
238 if (!data) return 1;
239
240 // Default copy ctor is good.
241 *from_d = new KeyData(*data);
242 if (*from_d) return 1;
243 return 0;
244 }
245
246 /* static */
free_key_data(void *,void * ptr,CRYPTO_EX_DATA *,int,long,void *)247 void Keymaster1Engine::free_key_data(void* /* parent */, void* ptr, CRYPTO_EX_DATA* /* data */,
248 // NOLINTNEXTLINE(google-runtime-int)
249 int /* index*/, long /* argl */, void* /* argp */) {
250 delete reinterpret_cast<KeyData*>(ptr);
251 }
252
Keymaster1Finish(const KeyData * key_data,const keymaster_blob_t & input,keymaster_blob_t * output)253 keymaster_error_t Keymaster1Engine::Keymaster1Finish(const KeyData* key_data,
254 const keymaster_blob_t& input,
255 keymaster_blob_t* output) {
256 if (key_data->op_handle == 0) return KM_ERROR_UNKNOWN_ERROR;
257
258 size_t input_consumed;
259 // Note: devices are required to consume all input in a single update call for undigested
260 // signing operations and encryption operations. No need to loop here.
261 keymaster_error_t error =
262 device()->update(device(), key_data->op_handle, &key_data->finish_params, &input,
263 &input_consumed, nullptr /* out_params */, nullptr /* output */);
264 if (error != KM_ERROR_OK) return error;
265
266 return device()->finish(device(), key_data->op_handle, &key_data->finish_params,
267 nullptr /* signature */, nullptr /* out_params */, output);
268 }
269
270 /* static */
rsa_sign_raw(RSA * rsa,size_t * out_len,uint8_t * out,size_t max_out,const uint8_t * in,size_t in_len,int padding)271 int Keymaster1Engine::rsa_sign_raw(RSA* rsa, size_t* out_len, uint8_t* out, size_t max_out,
272 const uint8_t* in, size_t in_len, int padding) {
273 KeyData* key_data = instance_->GetData(rsa);
274 if (!key_data) return 0;
275
276 if (padding != key_data->expected_openssl_padding) {
277 LOG_E("Expected sign_raw with padding %d but got padding %d",
278 key_data->expected_openssl_padding, padding);
279 return KM_ERROR_UNKNOWN_ERROR;
280 }
281
282 keymaster_blob_t input = {in, in_len};
283 keymaster_blob_t output;
284 key_data->error = instance_->Keymaster1Finish(key_data, input, &output);
285 if (key_data->error != KM_ERROR_OK) return 0;
286 unique_ptr<uint8_t, Malloc_Delete> output_deleter(const_cast<uint8_t*>(output.data));
287
288 *out_len = std::min(output.data_length, max_out);
289 memcpy(out, output.data, *out_len);
290 return 1;
291 }
292
293 /* static */
rsa_decrypt(RSA * rsa,size_t * out_len,uint8_t * out,size_t max_out,const uint8_t * in,size_t in_len,int padding)294 int Keymaster1Engine::rsa_decrypt(RSA* rsa, size_t* out_len, uint8_t* out, size_t max_out,
295 const uint8_t* in, size_t in_len, int padding) {
296 KeyData* key_data = instance_->GetData(rsa);
297 if (!key_data) return 0;
298
299 if (padding != key_data->expected_openssl_padding) {
300 LOG_E("Expected sign_raw with padding %d but got padding %d",
301 key_data->expected_openssl_padding, padding);
302 return KM_ERROR_UNKNOWN_ERROR;
303 }
304
305 keymaster_blob_t input = {in, in_len};
306 keymaster_blob_t output;
307 key_data->error = instance_->Keymaster1Finish(key_data, input, &output);
308 if (key_data->error != KM_ERROR_OK) return 0;
309 unique_ptr<uint8_t, Malloc_Delete> output_deleter(const_cast<uint8_t*>(output.data));
310
311 *out_len = std::min(output.data_length, max_out);
312 memcpy(out, output.data, *out_len);
313 return 1;
314 }
315
316 /* static */
ecdsa_sign(const uint8_t * digest,size_t digest_len,uint8_t * sig,unsigned int * sig_len,EC_KEY * ec_key)317 int Keymaster1Engine::ecdsa_sign(const uint8_t* digest, size_t digest_len, uint8_t* sig,
318 unsigned int* sig_len, EC_KEY* ec_key) {
319 KeyData* key_data = instance_->GetData(ec_key);
320 if (!key_data) return 0;
321
322 // Truncate digest if it's too long
323 size_t max_input_len = (ec_group_size_bits(ec_key) + 7) / 8;
324 if (digest_len > max_input_len) digest_len = max_input_len;
325
326 keymaster_blob_t input = {digest, digest_len};
327 keymaster_blob_t output;
328 key_data->error = instance_->Keymaster1Finish(key_data, input, &output);
329 if (key_data->error != KM_ERROR_OK) return 0;
330 unique_ptr<uint8_t, Malloc_Delete> output_deleter(const_cast<uint8_t*>(output.data));
331
332 *sig_len = std::min(output.data_length, ECDSA_size(ec_key));
333 memcpy(sig, output.data, *sig_len);
334 return 1;
335 }
336
GetKeymaster1PublicKey(const KeymasterKeyBlob & blob,const AuthorizationSet & additional_params,keymaster_error_t * error) const337 EVP_PKEY* Keymaster1Engine::GetKeymaster1PublicKey(const KeymasterKeyBlob& blob,
338 const AuthorizationSet& additional_params,
339 keymaster_error_t* error) const {
340 keymaster_blob_t client_id = {nullptr, 0};
341 keymaster_blob_t app_data = {nullptr, 0};
342 keymaster_blob_t* client_id_ptr = nullptr;
343 keymaster_blob_t* app_data_ptr = nullptr;
344 if (additional_params.GetTagValue(TAG_APPLICATION_ID, &client_id)) client_id_ptr = &client_id;
345 if (additional_params.GetTagValue(TAG_APPLICATION_DATA, &app_data)) app_data_ptr = &app_data;
346
347 keymaster_blob_t export_data = {nullptr, 0};
348 *error = keymaster1_device_->export_key(keymaster1_device_, KM_KEY_FORMAT_X509, &blob,
349 client_id_ptr, app_data_ptr, &export_data);
350 if (*error != KM_ERROR_OK) return nullptr;
351
352 unique_ptr<uint8_t, Malloc_Delete> pub_key(const_cast<uint8_t*>(export_data.data));
353
354 const uint8_t* p = export_data.data;
355 auto result = d2i_PUBKEY(nullptr /* allocate new struct */, &p, export_data.data_length);
356 if (!result) {
357 *error = TranslateLastOpenSslError();
358 }
359 return result;
360 }
361
BuildRsaMethod()362 RSA_METHOD Keymaster1Engine::BuildRsaMethod() {
363 RSA_METHOD method = {};
364
365 method.common.is_static = 1;
366 method.sign_raw = Keymaster1Engine::rsa_sign_raw;
367 method.decrypt = Keymaster1Engine::rsa_decrypt;
368 method.flags = RSA_FLAG_OPAQUE;
369
370 return method;
371 }
372
BuildEcdsaMethod()373 ECDSA_METHOD Keymaster1Engine::BuildEcdsaMethod() {
374 ECDSA_METHOD method = {};
375
376 method.common.is_static = 1;
377 method.sign = Keymaster1Engine::ecdsa_sign;
378 method.flags = ECDSA_FLAG_OPAQUE;
379
380 return method;
381 }
382
383 } // namespace keymaster
384