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1 // Copyright (c) 2015 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 "components/safe_browsing_db/safe_browsing_db_util.h" | |
6 | |
7 #include "crypto/sha2.h" | |
8 | |
9 // Utility functions ----------------------------------------------------------- | |
10 | |
11 namespace { | |
12 bool IsKnownList(const std::string& name) { | |
13 for (size_t i = 0; i < arraysize(kAllLists); ++i) { | |
14 if (!strcmp(kAllLists[i], name.c_str())) { | |
15 return true; | |
16 } | |
17 } | |
18 return false; | |
19 } | |
20 } // namespace | |
21 | |
22 | |
23 namespace safe_browsing { | |
24 | |
25 // Listnames that browser can process. | |
26 // TODO(shess): This shouldn't be OS-driven <http://crbug.com/394379> | |
27 #if defined(OS_ANDROID) | |
28 // NOTE(shess): This difference is also reflected in the store name in | |
29 // safe_browsing_database.cc. | |
30 const char kMalwareList[] = "goog-mobilemalware-shavar"; | |
31 const char kPhishingList[] = "goog-mobilephish-shavar"; | |
32 #else | |
33 const char kMalwareList[] = "goog-malware-shavar"; | |
34 const char kPhishingList[] = "goog-phish-shavar"; | |
35 #endif | |
36 const char kBinUrlList[] = "goog-badbinurl-shavar"; | |
37 const char kCsdWhiteList[] = "goog-csdwhite-sha256"; | |
38 const char kDownloadWhiteList[] = "goog-downloadwhite-digest256"; | |
39 const char kExtensionBlacklist[] = "goog-badcrxids-digestvar"; | |
40 const char kIPBlacklist[] = "goog-badip-digest256"; | |
41 const char kUnwantedUrlList[] = "goog-unwanted-shavar"; | |
42 const char kInclusionWhitelist[] = "goog-csdinclusionwhite-sha256"; | |
43 | |
44 const char* kAllLists[9] = { | |
45 kMalwareList, | |
46 kPhishingList, | |
47 kBinUrlList, | |
48 kCsdWhiteList, | |
49 kDownloadWhiteList, | |
50 kExtensionBlacklist, | |
51 kIPBlacklist, | |
52 kUnwantedUrlList, | |
53 kInclusionWhitelist, | |
54 }; | |
55 | |
56 ListType GetListId(const base::StringPiece& name) { | |
57 ListType id; | |
58 if (name == kMalwareList) { | |
59 id = MALWARE; | |
60 } else if (name == kPhishingList) { | |
61 id = PHISH; | |
62 } else if (name == kBinUrlList) { | |
63 id = BINURL; | |
64 } else if (name == kCsdWhiteList) { | |
65 id = CSDWHITELIST; | |
66 } else if (name == kDownloadWhiteList) { | |
67 id = DOWNLOADWHITELIST; | |
68 } else if (name == kExtensionBlacklist) { | |
69 id = EXTENSIONBLACKLIST; | |
70 } else if (name == kIPBlacklist) { | |
71 id = IPBLACKLIST; | |
72 } else if (name == kUnwantedUrlList) { | |
73 id = UNWANTEDURL; | |
74 } else if (name == kInclusionWhitelist) { | |
75 id = INCLUSIONWHITELIST; | |
76 } else { | |
77 id = INVALID; | |
78 } | |
79 return id; | |
80 } | |
81 | |
82 bool GetListName(ListType list_id, std::string* list) { | |
83 switch (list_id) { | |
84 case MALWARE: | |
85 *list = kMalwareList; | |
86 break; | |
87 case PHISH: | |
88 *list = kPhishingList; | |
89 break; | |
90 case BINURL: | |
91 *list = kBinUrlList; | |
92 break; | |
93 case CSDWHITELIST: | |
94 *list = kCsdWhiteList; | |
95 break; | |
96 case DOWNLOADWHITELIST: | |
97 *list = kDownloadWhiteList; | |
98 break; | |
99 case EXTENSIONBLACKLIST: | |
100 *list = kExtensionBlacklist; | |
101 break; | |
102 case IPBLACKLIST: | |
103 *list = kIPBlacklist; | |
104 break; | |
105 case UNWANTEDURL: | |
106 *list = kUnwantedUrlList; | |
107 break; | |
108 case INCLUSIONWHITELIST: | |
109 *list = kInclusionWhitelist; | |
110 break; | |
111 default: | |
112 return false; | |
113 } | |
114 DCHECK(IsKnownList(*list)); | |
115 return true; | |
116 } | |
117 | |
118 | |
119 SBFullHash SBFullHashForString(const base::StringPiece& str) { | |
120 SBFullHash h; | |
121 crypto::SHA256HashString(str, &h.full_hash, sizeof(h.full_hash)); | |
122 return h; | |
123 } | |
124 | |
125 SBFullHash StringToSBFullHash(const std::string& hash_in) { | |
126 DCHECK_EQ(crypto::kSHA256Length, hash_in.size()); | |
127 SBFullHash hash_out; | |
128 memcpy(hash_out.full_hash, hash_in.data(), crypto::kSHA256Length); | |
129 return hash_out; | |
130 } | |
131 | |
132 std::string SBFullHashToString(const SBFullHash& hash) { | |
133 DCHECK_EQ(crypto::kSHA256Length, sizeof(hash.full_hash)); | |
134 return std::string(hash.full_hash, sizeof(hash.full_hash)); | |
135 } | |
136 | |
137 | |
138 std::string Unescape(const std::string& url) { | |
139 std::string unescaped_str(url); | |
140 std::string old_unescaped_str; | |
141 const int kMaxLoopIterations = 1024; | |
142 int loop_var = 0; | |
143 do { | |
144 old_unescaped_str = unescaped_str; | |
145 unescaped_str = net::UnescapeURLComponent( | |
146 old_unescaped_str, net::UnescapeRule::SPOOFING_AND_CONTROL_CHARS | | |
147 net::UnescapeRule::SPACES | | |
148 net::UnescapeRule::URL_SPECIAL_CHARS); | |
149 } while (unescaped_str != old_unescaped_str && ++loop_var <= | |
150 kMaxLoopIterations); | |
151 | |
152 return unescaped_str; | |
153 } | |
154 | |
155 std::string Escape(const std::string& url) { | |
156 std::string escaped_str; | |
157 const char* kHexString = "0123456789ABCDEF"; | |
158 for (size_t i = 0; i < url.length(); i++) { | |
159 unsigned char c = static_cast<unsigned char>(url[i]); | |
160 if (c <= ' ' || c > '~' || c == '#' || c == '%') { | |
161 escaped_str.push_back('%'); | |
162 escaped_str.push_back(kHexString[c >> 4]); | |
163 escaped_str.push_back(kHexString[c & 0xf]); | |
164 } else { | |
165 escaped_str.push_back(c); | |
166 } | |
167 } | |
168 | |
169 return escaped_str; | |
170 } | |
171 | |
172 std::string RemoveConsecutiveChars(const std::string& str, const char c) { | |
173 std::string output(str); | |
174 std::string string_to_find; | |
175 std::string::size_type loc = 0; | |
176 string_to_find.append(2, c); | |
177 while ((loc = output.find(string_to_find, loc)) != std::string::npos) { | |
178 output.erase(loc, 1); | |
179 } | |
180 | |
181 return output; | |
182 } | |
183 | |
184 // Canonicalizes url as per Google Safe Browsing Specification. | |
185 // See section 6.1 in | |
186 // http://code.google.com/p/google-safe-browsing/wiki/Protocolv2Spec. | |
187 void CanonicalizeUrl(const GURL& url, | |
188 std::string* canonicalized_hostname, | |
189 std::string* canonicalized_path, | |
190 std::string* canonicalized_query) { | |
191 DCHECK(url.is_valid()); | |
192 | |
193 // We only canonicalize "normal" URLs. | |
194 if (!url.IsStandard()) | |
195 return; | |
196 | |
197 // Following canonicalization steps are excluded since url parsing takes care | |
198 // of those :- | |
199 // 1. Remove any tab (0x09), CR (0x0d), and LF (0x0a) chars from url. | |
200 // (Exclude escaped version of these chars). | |
201 // 2. Normalize hostname to 4 dot-seperated decimal values. | |
202 // 3. Lowercase hostname. | |
203 // 4. Resolve path sequences "/../" and "/./". | |
204 | |
205 // That leaves us with the following :- | |
206 // 1. Remove fragment in URL. | |
207 GURL url_without_fragment; | |
208 GURL::Replacements f_replacements; | |
209 f_replacements.ClearRef(); | |
210 f_replacements.ClearUsername(); | |
211 f_replacements.ClearPassword(); | |
212 url_without_fragment = url.ReplaceComponents(f_replacements); | |
213 | |
214 // 2. Do URL unescaping until no more hex encoded characters exist. | |
215 std::string url_unescaped_str(Unescape(url_without_fragment.spec())); | |
216 url::Parsed parsed; | |
217 url::ParseStandardURL(url_unescaped_str.data(), url_unescaped_str.length(), | |
218 &parsed); | |
219 | |
220 // 3. In hostname, remove all leading and trailing dots. | |
221 const std::string host = | |
222 (parsed.host.len > 0) | |
223 ? url_unescaped_str.substr(parsed.host.begin, parsed.host.len) | |
224 : std::string(); | |
225 std::string host_without_end_dots; | |
226 base::TrimString(host, ".", &host_without_end_dots); | |
227 | |
228 // 4. In hostname, replace consecutive dots with a single dot. | |
229 std::string host_without_consecutive_dots(RemoveConsecutiveChars( | |
230 host_without_end_dots, '.')); | |
231 | |
232 // 5. In path, replace runs of consecutive slashes with a single slash. | |
233 std::string path = | |
234 (parsed.path.len > 0) | |
235 ? url_unescaped_str.substr(parsed.path.begin, parsed.path.len) | |
236 : std::string(); | |
237 std::string path_without_consecutive_slash(RemoveConsecutiveChars(path, '/')); | |
238 | |
239 url::Replacements<char> hp_replacements; | |
240 hp_replacements.SetHost( | |
241 host_without_consecutive_dots.data(), | |
242 url::Component(0, host_without_consecutive_dots.length())); | |
243 hp_replacements.SetPath( | |
244 path_without_consecutive_slash.data(), | |
245 url::Component(0, path_without_consecutive_slash.length())); | |
246 | |
247 std::string url_unescaped_with_can_hostpath; | |
248 url::StdStringCanonOutput output(&url_unescaped_with_can_hostpath); | |
249 url::Parsed temp_parsed; | |
250 url::ReplaceComponents(url_unescaped_str.data(), | |
251 url_unescaped_str.length(), | |
252 parsed, | |
253 hp_replacements, | |
254 NULL, | |
255 &output, | |
256 &temp_parsed); | |
257 output.Complete(); | |
258 | |
259 // 6. Step needed to revert escaping done in url::ReplaceComponents. | |
260 url_unescaped_with_can_hostpath = Unescape(url_unescaped_with_can_hostpath); | |
261 | |
262 // 7. After performing all above steps, percent-escape all chars in url which | |
263 // are <= ASCII 32, >= 127, #, %. Escapes must be uppercase hex characters. | |
264 std::string escaped_canon_url_str(Escape(url_unescaped_with_can_hostpath)); | |
265 url::Parsed final_parsed; | |
266 url::ParseStandardURL(escaped_canon_url_str.data(), | |
267 escaped_canon_url_str.length(), | |
268 &final_parsed); | |
269 | |
270 if (canonicalized_hostname && final_parsed.host.len > 0) { | |
271 *canonicalized_hostname = | |
272 escaped_canon_url_str.substr(final_parsed.host.begin, | |
273 final_parsed.host.len); | |
274 } | |
275 if (canonicalized_path && final_parsed.path.len > 0) { | |
276 *canonicalized_path = escaped_canon_url_str.substr(final_parsed.path.begin, | |
277 final_parsed.path.len); | |
278 } | |
279 if (canonicalized_query && final_parsed.query.len > 0) { | |
280 *canonicalized_query = escaped_canon_url_str.substr( | |
281 final_parsed.query.begin, final_parsed.query.len); | |
282 } | |
283 } | |
284 | |
285 void GenerateHostsToCheck(const GURL& url, std::vector<std::string>* hosts) { | |
286 hosts->clear(); | |
287 | |
288 std::string canon_host; | |
289 CanonicalizeUrl(url, &canon_host, NULL, NULL); | |
290 | |
291 const std::string host = canon_host; // const sidesteps GCC bugs below! | |
292 if (host.empty()) | |
293 return; | |
294 | |
295 // Per the Safe Browsing Protocol v2 spec, we try the host, and also up to 4 | |
296 // hostnames formed by starting with the last 5 components and successively | |
297 // removing the leading component. The last component isn't examined alone, | |
298 // since it's the TLD or a subcomponent thereof. | |
299 // | |
300 // Note that we don't need to be clever about stopping at the "real" eTLD -- | |
301 // the data on the server side has been filtered to ensure it will not | |
302 // blacklist a whole TLD, and it's not significantly slower on our side to | |
303 // just check too much. | |
304 // | |
305 // Also note that because we have a simple blacklist, not some sort of complex | |
306 // whitelist-in-blacklist or vice versa, it doesn't matter what order we check | |
307 // these in. | |
308 const size_t kMaxHostsToCheck = 4; | |
309 bool skipped_last_component = false; | |
310 for (std::string::const_reverse_iterator i(host.rbegin()); | |
311 i != host.rend() && hosts->size() < kMaxHostsToCheck; ++i) { | |
312 if (*i == '.') { | |
313 if (skipped_last_component) | |
314 hosts->push_back(std::string(i.base(), host.end())); | |
315 else | |
316 skipped_last_component = true; | |
317 } | |
318 } | |
319 hosts->push_back(host); | |
320 } | |
321 | |
322 void GeneratePathsToCheck(const GURL& url, std::vector<std::string>* paths) { | |
323 paths->clear(); | |
324 | |
325 std::string canon_path; | |
326 std::string canon_query; | |
327 CanonicalizeUrl(url, NULL, &canon_path, &canon_query); | |
328 | |
329 const std::string path = canon_path; // const sidesteps GCC bugs below! | |
330 const std::string query = canon_query; | |
331 if (path.empty()) | |
332 return; | |
333 | |
334 // Per the Safe Browsing Protocol v2 spec, we try the exact path with/without | |
335 // the query parameters, and also up to 4 paths formed by starting at the root | |
336 // and adding more path components. | |
337 // | |
338 // As with the hosts above, it doesn't matter what order we check these in. | |
339 const size_t kMaxPathsToCheck = 4; | |
340 for (std::string::const_iterator i(path.begin()); | |
341 i != path.end() && paths->size() < kMaxPathsToCheck; ++i) { | |
342 if (*i == '/') | |
343 paths->push_back(std::string(path.begin(), i + 1)); | |
344 } | |
345 | |
346 if (!paths->empty() && paths->back() != path) | |
347 paths->push_back(path); | |
348 | |
349 if (!query.empty()) | |
350 paths->push_back(path + "?" + query); | |
351 } | |
352 | |
353 void GeneratePatternsToCheck(const GURL& url, std::vector<std::string>* urls) { | |
354 std::vector<std::string> hosts, paths; | |
355 GenerateHostsToCheck(url, &hosts); | |
356 GeneratePathsToCheck(url, &paths); | |
357 for (size_t h = 0; h < hosts.size(); ++h) { | |
358 for (size_t p = 0; p < paths.size(); ++p) { | |
359 urls->push_back(hosts[h] + paths[p]); | |
360 } | |
361 } | |
362 } | |
363 | |
364 } // namespace safe_browsing | |
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