1 // Copyright (c) 2011 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 #ifndef NET_BASE_ESCAPE_H_ 6 #define NET_BASE_ESCAPE_H_ 7 #pragma once 8 9 #include <string> 10 #include <vector> 11 12 #include "base/basictypes.h" 13 #include "base/string16.h" 14 15 // Escaping -------------------------------------------------------------------- 16 17 // Escape a file. This includes: 18 // non-printable, non-7bit, and (including space) "#%:<>?[\]^`{|} 19 std::string EscapePath(const std::string& path); 20 21 // Escape application/x-www-form-urlencoded content. This includes: 22 // non-printable, non-7bit, and (including space) ?>=<;+'&%$#"![\]^`{|} 23 // Space is escaped as + and other special characters as %XX (hex). 24 std::string EscapeUrlEncodedData(const std::string& path); 25 26 // Escape all non-ASCII input. 27 std::string EscapeNonASCII(const std::string& input); 28 29 // Escapes characters in text suitable for use as an external protocol handler 30 // command. 31 // We %XX everything except alphanumerics and %-_.!~*'() and the restricted 32 // chracters (;/?:@&=+$,). 33 std::string EscapeExternalHandlerValue(const std::string& text); 34 35 // Append the given character to the output string, escaping the character if 36 // the character would be interpretted as an HTML delimiter. 37 void AppendEscapedCharForHTML(char c, std::string* output); 38 39 // Escape chars that might cause this text to be interpretted as HTML tags. 40 std::string EscapeForHTML(const std::string& text); 41 string16 EscapeForHTML(const string16& text); 42 43 // Unescaping ------------------------------------------------------------------ 44 45 class UnescapeRule { 46 public: 47 // A combination of the following flags that is passed to the unescaping 48 // functions. 49 typedef uint32 Type; 50 51 enum { 52 // Don't unescape anything at all. 53 NONE = 0, 54 55 // Don't unescape anything special, but all normal unescaping will happen. 56 // This is a placeholder and can't be combined with other flags (since it's 57 // just the absence of them). All other unescape rules imply "normal" in 58 // addition to their special meaning. Things like escaped letters, digits, 59 // and most symbols will get unescaped with this mode. 60 NORMAL = 1, 61 62 // Convert %20 to spaces. In some places where we're showing URLs, we may 63 // want this. In places where the URL may be copied and pasted out, then 64 // you wouldn't want this since it might not be interpreted in one piece 65 // by other applications. 66 SPACES = 2, 67 68 // Unescapes various characters that will change the meaning of URLs, 69 // including '%', '+', '&', '/', '#'. If we unescaped these characters, the 70 // resulting URL won't be the same as the source one. This flag is used when 71 // generating final output like filenames for URLs where we won't be 72 // interpreting as a URL and want to do as much unescaping as possible. 73 URL_SPECIAL_CHARS = 4, 74 75 // Unescapes control characters such as %01. This INCLUDES NULLs. This is 76 // used for rare cases such as data: URL decoding where the result is binary 77 // data. You should not use this for normal URLs! 78 CONTROL_CHARS = 8, 79 80 // URL queries use "+" for space. This flag controls that replacement. 81 REPLACE_PLUS_WITH_SPACE = 16, 82 }; 83 }; 84 85 // Unescapes |escaped_text| and returns the result. 86 // Unescaping consists of looking for the exact pattern "%XX", where each X is 87 // a hex digit, and converting to the character with the numerical value of 88 // those digits. Thus "i%20=%203%3b" unescapes to "i = 3;". 89 // 90 // Watch out: this doesn't necessarily result in the correct final result, 91 // because the encoding may be unknown. For example, the input might be ASCII, 92 // which, after unescaping, is supposed to be interpreted as UTF-8, and then 93 // converted into full wide chars. This function won't tell you if any 94 // conversions need to take place, it only unescapes. 95 std::string UnescapeURLComponent(const std::string& escaped_text, 96 UnescapeRule::Type rules); 97 string16 UnescapeURLComponent(const string16& escaped_text, 98 UnescapeRule::Type rules); 99 100 // Unescapes the given substring as a URL, and then tries to interpret the 101 // result as being encoded as UTF-8. If the result is convertable into UTF-8, it 102 // will be returned as converted. If it is not, the original escaped string will 103 // be converted into a string16 and returned. (|offset[s]_for_adjustment|) 104 // specifies one or more offsets into the source strings; each offset will be 105 // adjusted to point at the same logical place in the result strings during 106 // decoding. If this isn't possible because an offset points past the end of 107 // the source strings or into the middle of a multibyte sequence, the offending 108 // offset will be set to std::wstring::npos. |offset[s]_for_adjustment| may be 109 // NULL. 110 string16 UnescapeAndDecodeUTF8URLComponent(const std::string& text, 111 UnescapeRule::Type rules, 112 size_t* offset_for_adjustment); 113 string16 UnescapeAndDecodeUTF8URLComponentWithOffsets( 114 const std::string& text, 115 UnescapeRule::Type rules, 116 std::vector<size_t>* offsets_for_adjustment); 117 118 // Unescape the following ampersand character codes from |text|: 119 // < > & " ' 120 string16 UnescapeForHTML(const string16& text); 121 122 // Deprecated ------------------------------------------------------------------ 123 124 // Escapes characters in text suitable for use as a query parameter value. 125 // We %XX everything except alphanumerics and -_.!~*'() 126 // Spaces change to "+" unless you pass usePlus=false. 127 // This is basically the same as encodeURIComponent in javascript. 128 // For the string16 version, we do a conversion to charset before encoding the 129 // string. If the charset doesn't exist, we return false. 130 std::string EscapeQueryParamValue(const std::string& text, bool use_plus); 131 bool EscapeQueryParamValue(const string16& text, const char* codepage, 132 bool use_plus, string16* escaped); 133 134 // A specialized version of EscapeQueryParamValue for string16s that 135 // assumes the codepage is UTF8. This is provided as a convenience. 136 string16 EscapeQueryParamValueUTF8(const string16& text, bool use_plus); 137 138 // Private Functions (Exposed for Unit Testing) -------------------------------- 139 140 // A function called by std::for_each that will adjust any offset which occurs 141 // after one or more encoded characters. 142 struct AdjustEncodingOffset { 143 typedef std::vector<size_t> Adjustments; 144 145 explicit AdjustEncodingOffset(const Adjustments& adjustments); 146 void operator()(size_t& offset); 147 148 const Adjustments& adjustments; 149 }; 150 151 #endif // NET_BASE_ESCAPE_H_ 152