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1 // Copyright 2016 The Chromium Authors. All rights reserved. | 1 // Copyright 2016 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #include "components/safe_browsing_db/v4_protocol_manager_util.h" | 5 #include "components/safe_browsing_db/v4_protocol_manager_util.h" |
6 | 6 |
7 #include "base/base64.h" | 7 #include "base/base64.h" |
8 #include "base/metrics/sparse_histogram.h" | 8 #include "base/metrics/sparse_histogram.h" |
9 #include "base/rand_util.h" | 9 #include "base/rand_util.h" |
10 #include "base/strings/string_util.h" | |
11 #include "base/strings/stringprintf.h" | 10 #include "base/strings/stringprintf.h" |
12 #include "crypto/sha2.h" | |
13 #include "net/base/escape.h" | 11 #include "net/base/escape.h" |
14 #include "net/http/http_request_headers.h" | 12 #include "net/http/http_request_headers.h" |
15 #include "url/url_util.h" | |
16 | 13 |
17 using base::Time; | 14 using base::Time; |
18 using base::TimeDelta; | 15 using base::TimeDelta; |
19 | 16 |
20 namespace safe_browsing { | 17 namespace safe_browsing { |
21 | 18 |
22 namespace { | |
23 | |
24 std::string Unescape(const std::string& url) { | |
25 std::string unescaped_str(url); | |
26 const int kMaxLoopIterations = 1024; | |
27 size_t old_size = 0; | |
28 int loop_var = 0; | |
29 do { | |
30 old_size = unescaped_str.size(); | |
31 unescaped_str = net::UnescapeURLComponent( | |
32 unescaped_str, | |
33 net::UnescapeRule::SPOOFING_AND_CONTROL_CHARS | | |
34 net::UnescapeRule::SPACES | net::UnescapeRule::PATH_SEPARATORS | | |
35 net::UnescapeRule::URL_SPECIAL_CHARS_EXCEPT_PATH_SEPARATORS); | |
36 } while (old_size != unescaped_str.size() && | |
37 ++loop_var <= kMaxLoopIterations); | |
38 | |
39 return unescaped_str; | |
40 } | |
41 | |
42 std::string Escape(const std::string& url) { | |
43 std::string escaped_str; | |
44 // The escaped string is larger so allocate double the length to reduce the | |
45 // chance of the string being grown. | |
46 escaped_str.reserve(url.length() * 2); | |
47 const char* kHexString = "0123456789ABCDEF"; | |
48 for (size_t i = 0; i < url.length(); i++) { | |
49 unsigned char c = static_cast<unsigned char>(url[i]); | |
50 if (c <= ' ' || c > '~' || c == '#' || c == '%') { | |
51 escaped_str += '%'; | |
52 escaped_str += kHexString[c >> 4]; | |
53 escaped_str += kHexString[c & 0xf]; | |
54 } else { | |
55 escaped_str += c; | |
56 } | |
57 } | |
58 | |
59 return escaped_str; | |
60 } | |
61 | |
62 } // namespace | |
63 | |
64 std::ostream& operator<<(std::ostream& os, const UpdateListIdentifier& id) { | 19 std::ostream& operator<<(std::ostream& os, const UpdateListIdentifier& id) { |
65 os << "{hash: " << id.hash() << "; platform_type: " << id.platform_type | 20 os << "{hash: " << id.hash() << "; platform_type: " << id.platform_type |
66 << "; threat_entry_type: " << id.threat_entry_type | 21 << "; threat_entry_type: " << id.threat_entry_type |
67 << "; threat_type: " << id.threat_type << "}"; | 22 << "; threat_type: " << id.threat_type << "}"; |
68 return os; | 23 return os; |
69 } | 24 } |
70 | 25 |
71 // The Safe Browsing V4 server URL prefix. | 26 // The Safe Browsing V4 server URL prefix. |
72 const char kSbV4UrlPrefix[] = "https://safebrowsing.googleapis.com/v4"; | 27 const char kSbV4UrlPrefix[] = "https://safebrowsing.googleapis.com/v4"; |
73 | 28 |
(...skipping 102 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... |
176 } | 131 } |
177 | 132 |
178 // static | 133 // static |
179 void V4ProtocolManagerUtil::UpdateHeaders(net::HttpRequestHeaders* headers) { | 134 void V4ProtocolManagerUtil::UpdateHeaders(net::HttpRequestHeaders* headers) { |
180 // NOTE(vakh): The following header informs the envelope server (which sits in | 135 // NOTE(vakh): The following header informs the envelope server (which sits in |
181 // front of Google's stubby server) that the received GET request should be | 136 // front of Google's stubby server) that the received GET request should be |
182 // interpreted as a POST. | 137 // interpreted as a POST. |
183 headers->SetHeaderIfMissing("X-HTTP-Method-Override", "POST"); | 138 headers->SetHeaderIfMissing("X-HTTP-Method-Override", "POST"); |
184 } | 139 } |
185 | 140 |
186 // static | |
187 void V4ProtocolManagerUtil::UrlToFullHashes( | |
188 const GURL& url, | |
189 base::hash_set<FullHash>* full_hashes) { | |
190 std::string canon_host, canon_path, canon_query; | |
191 CanonicalizeUrl(url, &canon_host, &canon_path, &canon_query); | |
192 | |
193 std::vector<std::string> hosts; | |
194 if (url.HostIsIPAddress()) { | |
195 hosts.push_back(url.host()); | |
196 } else { | |
197 GenerateHostVariantsToCheck(canon_host, &hosts); | |
198 } | |
199 | |
200 std::vector<std::string> paths; | |
201 GeneratePathVariantsToCheck(canon_path, canon_query, &paths); | |
202 for (const std::string& host : hosts) { | |
203 for (const std::string& path : paths) { | |
204 full_hashes->insert(crypto::SHA256HashString(host + path)); | |
205 } | |
206 } | |
207 } | |
208 | |
209 // static | |
210 void V4ProtocolManagerUtil::GenerateHostsToCheck( | |
211 const GURL& url, | |
212 std::vector<std::string>* hosts) { | |
213 std::string canon_host; | |
214 CanonicalizeUrl(url, &canon_host, NULL, NULL); | |
215 GenerateHostVariantsToCheck(canon_host, hosts); | |
216 } | |
217 | |
218 // static | |
219 void V4ProtocolManagerUtil::GeneratePathsToCheck( | |
220 const GURL& url, | |
221 std::vector<std::string>* paths) { | |
222 std::string canon_path; | |
223 std::string canon_query; | |
224 CanonicalizeUrl(url, NULL, &canon_path, &canon_query); | |
225 GeneratePathVariantsToCheck(canon_path, canon_query, paths); | |
226 } | |
227 | |
228 // static | |
229 void V4ProtocolManagerUtil::GeneratePatternsToCheck( | |
230 const GURL& url, | |
231 std::vector<std::string>* urls) { | |
232 std::string canon_host; | |
233 std::string canon_path; | |
234 std::string canon_query; | |
235 CanonicalizeUrl(url, &canon_host, &canon_path, &canon_query); | |
236 | |
237 std::vector<std::string> hosts, paths; | |
238 GenerateHostVariantsToCheck(canon_host, &hosts); | |
239 GeneratePathVariantsToCheck(canon_path, canon_query, &paths); | |
240 for (size_t h = 0; h < hosts.size(); ++h) { | |
241 for (size_t p = 0; p < paths.size(); ++p) { | |
242 urls->push_back(hosts[h] + paths[p]); | |
243 } | |
244 } | |
245 } | |
246 | |
247 // static | |
248 void V4ProtocolManagerUtil::CanonicalizeUrl(const GURL& url, | |
249 std::string* canonicalized_hostname, | |
250 std::string* canonicalized_path, | |
251 std::string* canonicalized_query) { | |
252 DCHECK(url.is_valid()); | |
253 | |
254 // We only canonicalize "normal" URLs. | |
255 if (!url.IsStandard()) | |
256 return; | |
257 | |
258 // Following canonicalization steps are excluded since url parsing takes care | |
259 // of those :- | |
260 // 1. Remove any tab (0x09), CR (0x0d), and LF (0x0a) chars from url. | |
261 // (Exclude escaped version of these chars). | |
262 // 2. Normalize hostname to 4 dot-seperated decimal values. | |
263 // 3. Lowercase hostname. | |
264 // 4. Resolve path sequences "/../" and "/./". | |
265 | |
266 // That leaves us with the following :- | |
267 // 1. Remove fragment in URL. | |
268 GURL url_without_fragment; | |
269 GURL::Replacements f_replacements; | |
270 f_replacements.ClearRef(); | |
271 f_replacements.ClearUsername(); | |
272 f_replacements.ClearPassword(); | |
273 url_without_fragment = url.ReplaceComponents(f_replacements); | |
274 | |
275 // 2. Do URL unescaping until no more hex encoded characters exist. | |
276 std::string url_unescaped_str(Unescape(url_without_fragment.spec())); | |
277 url::Parsed parsed; | |
278 url::ParseStandardURL(url_unescaped_str.data(), url_unescaped_str.length(), | |
279 &parsed); | |
280 | |
281 // 3. In hostname, remove all leading and trailing dots. | |
282 base::StringPiece host; | |
283 if (parsed.host.len > 0) | |
284 host.set(url_unescaped_str.data() + parsed.host.begin, parsed.host.len); | |
285 | |
286 base::StringPiece host_without_end_dots = | |
287 base::TrimString(host, ".", base::TrimPositions::TRIM_ALL); | |
288 | |
289 // 4. In hostname, replace consecutive dots with a single dot. | |
290 std::string host_without_consecutive_dots( | |
291 RemoveConsecutiveChars(host_without_end_dots, '.')); | |
292 | |
293 // 5. In path, replace runs of consecutive slashes with a single slash. | |
294 base::StringPiece path; | |
295 if (parsed.path.len > 0) | |
296 path.set(url_unescaped_str.data() + parsed.path.begin, parsed.path.len); | |
297 std::string path_without_consecutive_slash(RemoveConsecutiveChars(path, '/')); | |
298 | |
299 url::Replacements<char> hp_replacements; | |
300 hp_replacements.SetHost( | |
301 host_without_consecutive_dots.data(), | |
302 url::Component(0, host_without_consecutive_dots.length())); | |
303 hp_replacements.SetPath( | |
304 path_without_consecutive_slash.data(), | |
305 url::Component(0, path_without_consecutive_slash.length())); | |
306 | |
307 std::string url_unescaped_with_can_hostpath; | |
308 url::StdStringCanonOutput output(&url_unescaped_with_can_hostpath); | |
309 url::Parsed temp_parsed; | |
310 url::ReplaceComponents(url_unescaped_str.data(), url_unescaped_str.length(), | |
311 parsed, hp_replacements, NULL, &output, &temp_parsed); | |
312 output.Complete(); | |
313 | |
314 // 6. Step needed to revert escaping done in url::ReplaceComponents. | |
315 url_unescaped_with_can_hostpath = Unescape(url_unescaped_with_can_hostpath); | |
316 | |
317 // 7. After performing all above steps, percent-escape all chars in url which | |
318 // are <= ASCII 32, >= 127, #, %. Escapes must be uppercase hex characters. | |
319 std::string escaped_canon_url_str(Escape(url_unescaped_with_can_hostpath)); | |
320 url::Parsed final_parsed; | |
321 url::ParseStandardURL(escaped_canon_url_str.data(), | |
322 escaped_canon_url_str.length(), &final_parsed); | |
323 | |
324 if (canonicalized_hostname && final_parsed.host.len > 0) { | |
325 *canonicalized_hostname = escaped_canon_url_str.substr( | |
326 final_parsed.host.begin, final_parsed.host.len); | |
327 } | |
328 if (canonicalized_path && final_parsed.path.len > 0) { | |
329 *canonicalized_path = escaped_canon_url_str.substr(final_parsed.path.begin, | |
330 final_parsed.path.len); | |
331 } | |
332 if (canonicalized_query && final_parsed.query.len > 0) { | |
333 *canonicalized_query = escaped_canon_url_str.substr( | |
334 final_parsed.query.begin, final_parsed.query.len); | |
335 } | |
336 } | |
337 | |
338 // static | |
339 std::string V4ProtocolManagerUtil::RemoveConsecutiveChars(base::StringPiece str, | |
340 const char c) { | |
341 std::string output; | |
342 // Output is at most the length of the original string. | |
343 output.reserve(str.size()); | |
344 | |
345 size_t i = 0; | |
346 while (i < str.size()) { | |
347 output.append(1, str[i++]); | |
348 if (str[i - 1] == c) { | |
349 while (i < str.size() && str[i] == c) { | |
350 i++; | |
351 } | |
352 } | |
353 } | |
354 | |
355 return output; | |
356 } | |
357 | |
358 // static | |
359 void V4ProtocolManagerUtil::GenerateHostVariantsToCheck( | |
360 const std::string& host, | |
361 std::vector<std::string>* hosts) { | |
362 hosts->clear(); | |
363 | |
364 if (host.empty()) | |
365 return; | |
366 | |
367 // Per the Safe Browsing Protocol v2 spec, we try the host, and also up to 4 | |
368 // hostnames formed by starting with the last 5 components and successively | |
369 // removing the leading component. The last component isn't examined alone, | |
370 // since it's the TLD or a subcomponent thereof. | |
371 // | |
372 // Note that we don't need to be clever about stopping at the "real" eTLD -- | |
373 // the data on the server side has been filtered to ensure it will not | |
374 // blacklist a whole TLD, and it's not significantly slower on our side to | |
375 // just check too much. | |
376 // | |
377 // Also note that because we have a simple blacklist, not some sort of complex | |
378 // whitelist-in-blacklist or vice versa, it doesn't matter what order we check | |
379 // these in. | |
380 const size_t kMaxHostsToCheck = 4; | |
381 bool skipped_last_component = false; | |
382 for (std::string::const_reverse_iterator i(host.rbegin()); | |
383 i != host.rend() && hosts->size() < kMaxHostsToCheck; ++i) { | |
384 if (*i == '.') { | |
385 if (skipped_last_component) | |
386 hosts->push_back(std::string(i.base(), host.end())); | |
387 else | |
388 skipped_last_component = true; | |
389 } | |
390 } | |
391 hosts->push_back(host); | |
392 } | |
393 | |
394 // static | |
395 void V4ProtocolManagerUtil::GeneratePathVariantsToCheck( | |
396 const std::string& path, | |
397 const std::string& query, | |
398 std::vector<std::string>* paths) { | |
399 paths->clear(); | |
400 | |
401 if (path.empty()) | |
402 return; | |
403 | |
404 // Per the Safe Browsing Protocol v2 spec, we try the exact path with/without | |
405 // the query parameters, and also up to 4 paths formed by starting at the root | |
406 // and adding more path components. | |
407 // | |
408 // As with the hosts above, it doesn't matter what order we check these in. | |
409 const size_t kMaxPathsToCheck = 4; | |
410 for (std::string::const_iterator i(path.begin()); | |
411 i != path.end() && paths->size() < kMaxPathsToCheck; ++i) { | |
412 if (*i == '/') | |
413 paths->push_back(std::string(path.begin(), i + 1)); | |
414 } | |
415 | |
416 if (!paths->empty() && paths->back() != path) | |
417 paths->push_back(path); | |
418 | |
419 if (!query.empty()) | |
420 paths->push_back(path + "?" + query); | |
421 } | |
422 | |
423 } // namespace safe_browsing | 141 } // namespace safe_browsing |
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