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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 #include "chrome/browser/policy/cloud_policy_validator.h" | |
6 | |
7 #include "base/bind.h" | |
8 #include "base/bind_helpers.h" | |
9 #include "base/message_loop.h" | |
10 #include "base/stl_util.h" | |
11 #include "chrome/browser/policy/cloud_policy_constants.h" | |
12 #include "chrome/browser/policy/proto/chrome_device_policy.pb.h" | |
13 #include "chrome/browser/policy/proto/chrome_extension_policy.pb.h" | |
14 #include "chrome/browser/policy/proto/cloud_policy.pb.h" | |
15 #include "chrome/browser/policy/proto/device_management_backend.pb.h" | |
16 #include "content/public/browser/browser_thread.h" | |
17 #include "crypto/signature_verifier.h" | |
18 #include "google_apis/gaia/gaia_auth_util.h" | |
19 | |
20 namespace em = enterprise_management; | |
21 | |
22 namespace policy { | |
23 | |
24 namespace { | |
25 | |
26 // Grace interval for policy timestamp checks, in seconds. | |
27 const int kTimestampGraceIntervalSeconds = 60; | |
28 | |
29 // DER-encoded ASN.1 object identifier for the SHA1-RSA signature algorithm. | |
30 const uint8 kSignatureAlgorithm[] = { | |
31 0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86, | |
32 0xf7, 0x0d, 0x01, 0x01, 0x05, 0x05, 0x00 | |
33 }; | |
34 | |
35 } // namespace | |
36 | |
37 CloudPolicyValidatorBase::~CloudPolicyValidatorBase() {} | |
38 | |
39 void CloudPolicyValidatorBase::ValidateTimestamp( | |
40 base::Time not_before, | |
41 base::Time now, | |
42 ValidateTimestampOption timestamp_option) { | |
43 // Timestamp should be from the past. We allow for a 1-minute grace interval | |
44 // to cover clock drift. | |
45 validation_flags_ |= VALIDATE_TIMESTAMP; | |
46 timestamp_not_before_ = | |
47 (not_before - base::Time::UnixEpoch()).InMilliseconds(); | |
48 timestamp_not_after_ = | |
49 ((now + base::TimeDelta::FromSeconds(kTimestampGraceIntervalSeconds)) - | |
50 base::Time::UnixEpoch()).InMillisecondsRoundedUp(); | |
51 timestamp_option_ = timestamp_option; | |
52 } | |
53 | |
54 void CloudPolicyValidatorBase::ValidateUsername( | |
55 const std::string& expected_user) { | |
56 validation_flags_ |= VALIDATE_USERNAME; | |
57 user_ = gaia::CanonicalizeEmail(expected_user); | |
58 } | |
59 | |
60 void CloudPolicyValidatorBase::ValidateDomain( | |
61 const std::string& expected_domain) { | |
62 validation_flags_ |= VALIDATE_DOMAIN; | |
63 domain_ = gaia::CanonicalizeDomain(expected_domain); | |
64 } | |
65 | |
66 void CloudPolicyValidatorBase::ValidateDMToken( | |
67 const std::string& token, | |
68 ValidateDMTokenOption dm_token_option) { | |
69 validation_flags_ |= VALIDATE_TOKEN; | |
70 token_ = token; | |
71 dm_token_option_ = dm_token_option; | |
72 } | |
73 | |
74 void CloudPolicyValidatorBase::ValidatePolicyType( | |
75 const std::string& policy_type) { | |
76 validation_flags_ |= VALIDATE_POLICY_TYPE; | |
77 policy_type_ = policy_type; | |
78 } | |
79 | |
80 void CloudPolicyValidatorBase::ValidateSettingsEntityId( | |
81 const std::string& settings_entity_id) { | |
82 validation_flags_ |= VALIDATE_ENTITY_ID; | |
83 settings_entity_id_ = settings_entity_id; | |
84 } | |
85 | |
86 void CloudPolicyValidatorBase::ValidatePayload() { | |
87 validation_flags_ |= VALIDATE_PAYLOAD; | |
88 } | |
89 | |
90 void CloudPolicyValidatorBase::ValidateSignature(const std::vector<uint8>& key, | |
91 bool allow_key_rotation) { | |
92 validation_flags_ |= VALIDATE_SIGNATURE; | |
93 key_ = std::string(reinterpret_cast<const char*>(vector_as_array(&key)), | |
94 key.size()); | |
95 allow_key_rotation_ = allow_key_rotation; | |
96 } | |
97 | |
98 void CloudPolicyValidatorBase::ValidateInitialKey() { | |
99 validation_flags_ |= VALIDATE_INITIAL_KEY; | |
100 } | |
101 | |
102 void CloudPolicyValidatorBase::ValidateAgainstCurrentPolicy( | |
103 const em::PolicyData* policy_data, | |
104 ValidateTimestampOption timestamp_option, | |
105 ValidateDMTokenOption dm_token_option) { | |
106 base::Time last_policy_timestamp; | |
107 std::string expected_dm_token; | |
108 if (policy_data) { | |
109 last_policy_timestamp = | |
110 base::Time::UnixEpoch() + | |
111 base::TimeDelta::FromMilliseconds(policy_data->timestamp()); | |
112 expected_dm_token = policy_data->request_token(); | |
113 } | |
114 ValidateTimestamp(last_policy_timestamp, base::Time::NowFromSystemTime(), | |
115 timestamp_option); | |
116 ValidateDMToken(expected_dm_token, dm_token_option); | |
117 } | |
118 | |
119 CloudPolicyValidatorBase::CloudPolicyValidatorBase( | |
120 scoped_ptr<em::PolicyFetchResponse> policy_response, | |
121 google::protobuf::MessageLite* payload) | |
122 : status_(VALIDATION_OK), | |
123 policy_(policy_response.Pass()), | |
124 payload_(payload), | |
125 validation_flags_(0), | |
126 timestamp_not_before_(0), | |
127 timestamp_not_after_(0), | |
128 timestamp_option_(TIMESTAMP_REQUIRED), | |
129 dm_token_option_(DM_TOKEN_REQUIRED), | |
130 allow_key_rotation_(false) {} | |
131 | |
132 // static | |
133 void CloudPolicyValidatorBase::PerformValidation( | |
134 scoped_ptr<CloudPolicyValidatorBase> self, | |
135 scoped_refptr<base::MessageLoopProxy> message_loop, | |
136 const base::Closure& completion_callback) { | |
137 // Run the validation activities on this thread. | |
138 self->RunValidation(); | |
139 | |
140 // Report completion on |message_loop|. | |
141 message_loop->PostTask( | |
142 FROM_HERE, | |
143 base::Bind(&CloudPolicyValidatorBase::ReportCompletion, | |
144 base::Passed(&self), | |
145 completion_callback)); | |
146 } | |
147 | |
148 // static | |
149 void CloudPolicyValidatorBase::ReportCompletion( | |
150 scoped_ptr<CloudPolicyValidatorBase> self, | |
151 const base::Closure& completion_callback) { | |
152 completion_callback.Run(); | |
153 } | |
154 | |
155 void CloudPolicyValidatorBase::RunValidation() { | |
156 policy_data_.reset(new em::PolicyData()); | |
157 RunChecks(); | |
158 } | |
159 | |
160 void CloudPolicyValidatorBase::RunChecks() { | |
161 status_ = VALIDATION_OK; | |
162 if ((policy_->has_error_code() && policy_->error_code() != 200) || | |
163 (policy_->has_error_message() && !policy_->error_message().empty())) { | |
164 LOG(ERROR) << "Error in policy blob." | |
165 << " code: " << policy_->error_code() | |
166 << " message: " << policy_->error_message(); | |
167 status_ = VALIDATION_ERROR_CODE_PRESENT; | |
168 return; | |
169 } | |
170 | |
171 // Parse policy data. | |
172 if (!policy_data_->ParseFromString(policy_->policy_data()) || | |
173 !policy_data_->IsInitialized()) { | |
174 LOG(ERROR) << "Failed to parse policy response"; | |
175 status_ = VALIDATION_PAYLOAD_PARSE_ERROR; | |
176 return; | |
177 } | |
178 | |
179 // Table of checks we run. These are sorted by descending severity of the | |
180 // error, s.t. the most severe check will determine the validation status. | |
181 static const struct { | |
182 int flag; | |
183 Status (CloudPolicyValidatorBase::* checkFunction)(); | |
184 } kCheckFunctions[] = { | |
185 { VALIDATE_SIGNATURE, &CloudPolicyValidatorBase::CheckSignature }, | |
186 { VALIDATE_INITIAL_KEY, &CloudPolicyValidatorBase::CheckInitialKey }, | |
187 { VALIDATE_POLICY_TYPE, &CloudPolicyValidatorBase::CheckPolicyType }, | |
188 { VALIDATE_ENTITY_ID, &CloudPolicyValidatorBase::CheckEntityId }, | |
189 { VALIDATE_TOKEN, &CloudPolicyValidatorBase::CheckToken }, | |
190 { VALIDATE_USERNAME, &CloudPolicyValidatorBase::CheckUsername }, | |
191 { VALIDATE_DOMAIN, &CloudPolicyValidatorBase::CheckDomain }, | |
192 { VALIDATE_TIMESTAMP, &CloudPolicyValidatorBase::CheckTimestamp }, | |
193 { VALIDATE_PAYLOAD, &CloudPolicyValidatorBase::CheckPayload }, | |
194 }; | |
195 | |
196 for (size_t i = 0; i < ARRAYSIZE_UNSAFE(kCheckFunctions); ++i) { | |
197 if (validation_flags_ & kCheckFunctions[i].flag) { | |
198 status_ = (this->*(kCheckFunctions[i].checkFunction))(); | |
199 if (status_ != VALIDATION_OK) | |
200 break; | |
201 } | |
202 } | |
203 } | |
204 | |
205 CloudPolicyValidatorBase::Status CloudPolicyValidatorBase::CheckSignature() { | |
206 const std::string* signature_key = &key_; | |
207 if (policy_->has_new_public_key() && allow_key_rotation_) { | |
208 signature_key = &policy_->new_public_key(); | |
209 if (!policy_->has_new_public_key_signature() || | |
210 !VerifySignature(policy_->new_public_key(), key_, | |
211 policy_->new_public_key_signature())) { | |
212 LOG(ERROR) << "New public key signature verification failed"; | |
213 return VALIDATION_BAD_SIGNATURE; | |
214 } | |
215 } | |
216 | |
217 if (!policy_->has_policy_data_signature() || | |
218 !VerifySignature(policy_->policy_data(), *signature_key, | |
219 policy_->policy_data_signature())) { | |
220 LOG(ERROR) << "Policy signature validation failed"; | |
221 return VALIDATION_BAD_SIGNATURE; | |
222 } | |
223 | |
224 return VALIDATION_OK; | |
225 } | |
226 | |
227 CloudPolicyValidatorBase::Status CloudPolicyValidatorBase::CheckInitialKey() { | |
228 if (!policy_->has_new_public_key() || | |
229 !policy_->has_policy_data_signature() || | |
230 !VerifySignature(policy_->policy_data(), policy_->new_public_key(), | |
231 policy_->policy_data_signature())) { | |
232 LOG(ERROR) << "Initial policy signature validation failed"; | |
233 return VALIDATION_BAD_INITIAL_SIGNATURE; | |
234 } | |
235 | |
236 return VALIDATION_OK; | |
237 } | |
238 | |
239 CloudPolicyValidatorBase::Status CloudPolicyValidatorBase::CheckPolicyType() { | |
240 if (!policy_data_->has_policy_type() || | |
241 policy_data_->policy_type() != policy_type_) { | |
242 LOG(ERROR) << "Wrong policy type " << policy_data_->policy_type(); | |
243 return VALIDATION_WRONG_POLICY_TYPE; | |
244 } | |
245 | |
246 return VALIDATION_OK; | |
247 } | |
248 | |
249 CloudPolicyValidatorBase::Status CloudPolicyValidatorBase::CheckEntityId() { | |
250 if (!policy_data_->has_settings_entity_id() || | |
251 policy_data_->settings_entity_id() != settings_entity_id_) { | |
252 LOG(ERROR) << "Wrong settings_entity_id " | |
253 << policy_data_->settings_entity_id() << ", expected " | |
254 << settings_entity_id_; | |
255 return VALIDATION_WRONG_SETTINGS_ENTITY_ID; | |
256 } | |
257 | |
258 return VALIDATION_OK; | |
259 } | |
260 | |
261 CloudPolicyValidatorBase::Status CloudPolicyValidatorBase::CheckTimestamp() { | |
262 if (!policy_data_->has_timestamp()) { | |
263 if (timestamp_option_ == TIMESTAMP_NOT_REQUIRED) { | |
264 return VALIDATION_OK; | |
265 } else { | |
266 LOG(ERROR) << "Policy timestamp missing"; | |
267 return VALIDATION_BAD_TIMESTAMP; | |
268 } | |
269 } | |
270 | |
271 if (policy_data_->timestamp() < timestamp_not_before_) { | |
272 LOG(ERROR) << "Policy too old: " << policy_data_->timestamp(); | |
273 return VALIDATION_BAD_TIMESTAMP; | |
274 } | |
275 if (policy_data_->timestamp() > timestamp_not_after_) { | |
276 LOG(ERROR) << "Policy from the future: " << policy_data_->timestamp(); | |
277 return VALIDATION_BAD_TIMESTAMP; | |
278 } | |
279 | |
280 return VALIDATION_OK; | |
281 } | |
282 | |
283 CloudPolicyValidatorBase::Status CloudPolicyValidatorBase::CheckToken() { | |
284 // Make sure the token matches the expected token (if any) and also | |
285 // make sure the token itself is valid (non-empty if DM_TOKEN_REQUIRED). | |
286 if (dm_token_option_ == DM_TOKEN_REQUIRED && | |
287 (!policy_data_->has_request_token() || | |
288 policy_data_->request_token().empty())) { | |
289 LOG(ERROR) << "Empty DM token encountered - expected: " << token_; | |
290 return VALIDATION_WRONG_TOKEN; | |
291 } | |
292 if (!token_.empty() && policy_data_->request_token() != token_) { | |
293 LOG(ERROR) << "Invalid DM token: " << policy_data_->request_token() | |
294 << " - expected: " << token_; | |
295 return VALIDATION_WRONG_TOKEN; | |
296 } | |
297 | |
298 return VALIDATION_OK; | |
299 } | |
300 | |
301 CloudPolicyValidatorBase::Status CloudPolicyValidatorBase::CheckUsername() { | |
302 if (!policy_data_->has_username()) { | |
303 LOG(ERROR) << "Policy is missing user name"; | |
304 return VALIDATION_BAD_USERNAME; | |
305 } | |
306 | |
307 std::string policy_username = | |
308 gaia::CanonicalizeEmail(gaia::SanitizeEmail(policy_data_->username())); | |
309 | |
310 if (user_ != policy_username) { | |
311 LOG(ERROR) << "Invalid user name " << policy_data_->username(); | |
312 return VALIDATION_BAD_USERNAME; | |
313 } | |
314 | |
315 return VALIDATION_OK; | |
316 } | |
317 | |
318 | |
319 CloudPolicyValidatorBase::Status CloudPolicyValidatorBase::CheckDomain() { | |
320 if (!policy_data_->has_username()) { | |
321 LOG(ERROR) << "Policy is missing user name"; | |
322 return VALIDATION_BAD_USERNAME; | |
323 } | |
324 | |
325 std::string policy_domain = | |
326 gaia::ExtractDomainName( | |
327 gaia::CanonicalizeEmail( | |
328 gaia::SanitizeEmail(policy_data_->username()))); | |
329 | |
330 if (domain_ != policy_domain) { | |
331 LOG(ERROR) << "Invalid user name " << policy_data_->username(); | |
332 return VALIDATION_BAD_USERNAME; | |
333 } | |
334 | |
335 return VALIDATION_OK; | |
336 } | |
337 | |
338 CloudPolicyValidatorBase::Status CloudPolicyValidatorBase::CheckPayload() { | |
339 if (!policy_data_->has_policy_value() || | |
340 !payload_->ParseFromString(policy_data_->policy_value()) || | |
341 !payload_->IsInitialized()) { | |
342 LOG(ERROR) << "Failed to decode policy payload protobuf"; | |
343 return VALIDATION_POLICY_PARSE_ERROR; | |
344 } | |
345 | |
346 return VALIDATION_OK; | |
347 } | |
348 | |
349 // static | |
350 bool CloudPolicyValidatorBase::VerifySignature(const std::string& data, | |
351 const std::string& key, | |
352 const std::string& signature) { | |
353 crypto::SignatureVerifier verifier; | |
354 | |
355 if (!verifier.VerifyInit(kSignatureAlgorithm, sizeof(kSignatureAlgorithm), | |
356 reinterpret_cast<const uint8*>(signature.c_str()), | |
357 signature.size(), | |
358 reinterpret_cast<const uint8*>(key.c_str()), | |
359 key.size())) { | |
360 return false; | |
361 } | |
362 verifier.VerifyUpdate(reinterpret_cast<const uint8*>(data.c_str()), | |
363 data.size()); | |
364 return verifier.VerifyFinal(); | |
365 } | |
366 | |
367 template<typename PayloadProto> | |
368 CloudPolicyValidator<PayloadProto>::~CloudPolicyValidator() {} | |
369 | |
370 template<typename PayloadProto> | |
371 CloudPolicyValidator<PayloadProto>* CloudPolicyValidator<PayloadProto>::Create( | |
372 scoped_ptr<em::PolicyFetchResponse> policy_response) { | |
373 return new CloudPolicyValidator( | |
374 policy_response.Pass(), | |
375 scoped_ptr<PayloadProto>(new PayloadProto())); | |
376 } | |
377 | |
378 template<typename PayloadProto> | |
379 CloudPolicyValidator<PayloadProto>::CloudPolicyValidator( | |
380 scoped_ptr<em::PolicyFetchResponse> policy_response, | |
381 scoped_ptr<PayloadProto> payload) | |
382 : CloudPolicyValidatorBase(policy_response.Pass(), payload.get()), | |
383 payload_(payload.Pass()) {} | |
384 | |
385 template<typename PayloadProto> | |
386 void CloudPolicyValidator<PayloadProto>::StartValidation( | |
387 const CompletionCallback& completion_callback) { | |
388 content::BrowserThread::PostTask( | |
389 content::BrowserThread::FILE, FROM_HERE, | |
390 base::Bind(&CloudPolicyValidatorBase::PerformValidation, | |
391 base::Passed(scoped_ptr<CloudPolicyValidatorBase>(this)), | |
392 MessageLoop::current()->message_loop_proxy(), | |
393 base::Bind(completion_callback, this))); | |
394 } | |
395 | |
396 template class CloudPolicyValidator<em::ChromeDeviceSettingsProto>; | |
397 template class CloudPolicyValidator<em::CloudPolicySettings>; | |
398 template class CloudPolicyValidator<em::ExternalPolicyData>; | |
399 | |
400 } // namespace policy | |
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