1 // Copyright 2021 The Chromium Authors 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 <assert.h> 6 #include <stdlib.h> 7 #include <string> 8 9 #include "testing/libfuzzer/proto/url.pb.h" 10 11 namespace url_proto { 12 13 namespace { 14 SlashToString(int slash)15std::string SlashToString(int slash) { 16 if (slash == url_proto::Url::NONE) 17 return ""; 18 if (slash == url_proto::Url::FORWARD) 19 return "/"; 20 if (slash == url_proto::Url::BACKWARD) { 21 return "\\"; 22 } 23 assert(false && "Received unexpected value for slash"); 24 // Silence compiler warning about not returning in non-void function. 25 return ""; 26 } 27 28 } // namespace 29 Convert(const url_proto::Url & url)30std::string Convert(const url_proto::Url& url) { 31 // Build url_string piece by piece from url and then return it. 32 std::string url_string = std::string(""); 33 34 if (url.has_scheme()) { // Get the scheme if Url has it. 35 // Append the scheme to the url. This may be empty. Then append a colon 36 // which is mandatory if there is a scheme. 37 url_string += url.scheme() + ":"; 38 } 39 40 // Just append the slashes without doing validation, since it would be too 41 // complex. libFuzzer will hopefully figure out good values. 42 for (const int slash : url.slashes()) 43 url_string += SlashToString(slash); 44 45 // Get host. This is simple since hosts are simply strings according to our 46 // definition. 47 if (url.has_host()) { 48 // Get userinfo if libFuzzer set it. Ensure that user is separated 49 // from the password by ":" (if a password is included) and that userinfo is 50 // separated from the host by "@". 51 if (url.has_userinfo()) { 52 url_string += url.userinfo().user(); 53 if (url.userinfo().has_password()) { 54 url_string += ":"; 55 url_string += url.userinfo().password(); 56 } 57 url_string += "@"; 58 } 59 url_string += url.host(); 60 61 // As explained in url.proto, if libFuzzer included a port in url ensure 62 // that it is preceded by the host and then ":". 63 if (url.has_port()) 64 // Convert url.port() from an unsigned 32 bit int before appending it. 65 url_string += ":" + std::to_string(url.port()); 66 } 67 68 // Append the path segments to the url, with each segment separated by 69 // the path_separator. 70 bool first_segment = true; 71 std::string path_separator = SlashToString(url.path_separator()); 72 for (const std::string& path_segment : url.path()) { 73 // There does not need to be a path, but if there is a path and a host, 74 // ensure the path begins with "/". 75 if (url.has_host() && first_segment) { 76 url_string += "/" + path_segment; 77 first_segment = false; 78 } else 79 url_string += path_separator + path_segment; 80 } 81 82 // Queries must be started by "?". If libFuzzer included a query in url, 83 // ensure that it is preceded by "?". Also separate query components with 84 // ampersands as is the convention. 85 bool first_component = true; 86 for (const std::string& query_component : url.query()) { 87 if (first_component) { 88 url_string += "?" + query_component; 89 first_component = false; 90 } else 91 url_string += "&" + query_component; 92 } 93 94 // Fragments must be started by "#". If libFuzzer included a fragment 95 // in url, ensure that it is preceded by "#". 96 if (url.has_fragment()) 97 url_string += "#" + url.fragment(); 98 99 return url_string; 100 } 101 102 } // namespace url_proto 103