1 /*
2  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
3  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
4  *           (C) 2001 Dirk Mueller (mueller@kde.org)
5  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
6  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
7  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
8  *
9  * This library is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Library General Public
11  * License as published by the Free Software Foundation; either
12  * version 2 of the License, or (at your option) any later version.
13  *
14  * This library is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * Library General Public License for more details.
18  *
19  * You should have received a copy of the GNU Library General Public License
20  * along with this library; see the file COPYING.LIB.  If not, write to
21  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
22  * Boston, MA 02110-1301, USA.
23  */
24 
25 #include "config.h"
26 #include "FormDataBuilder.h"
27 
28 #include "Document.h"
29 #include "Frame.h"
30 #include "FrameLoader.h"
31 #include "TextEncoding.h"
32 
33 #include <limits>
34 #include <wtf/Assertions.h>
35 #include <wtf/HexNumber.h>
36 #include <wtf/text/CString.h>
37 #include <wtf/RandomNumber.h>
38 
39 namespace WebCore {
40 
41 // Helper functions
append(Vector<char> & buffer,char string)42 static inline void append(Vector<char>& buffer, char string)
43 {
44     buffer.append(string);
45 }
46 
append(Vector<char> & buffer,const char * string)47 static inline void append(Vector<char>& buffer, const char* string)
48 {
49     buffer.append(string, strlen(string));
50 }
51 
append(Vector<char> & buffer,const CString & string)52 static inline void append(Vector<char>& buffer, const CString& string)
53 {
54     buffer.append(string.data(), string.length());
55 }
56 
appendQuotedString(Vector<char> & buffer,const CString & string)57 static void appendQuotedString(Vector<char>& buffer, const CString& string)
58 {
59     // Append a string as a quoted value, escaping quotes and line breaks.
60     // FIXME: Is it correct to use percent escaping here? Other browsers do not encode these characters yet,
61     // so we should test popular servers to find out if there is an encoding form they can handle.
62     unsigned length = string.length();
63     for (unsigned i = 0; i < length; ++i) {
64         unsigned char c = string.data()[i];
65 
66         switch (c) {
67         case  0x0a:
68             append(buffer, "%0A");
69             break;
70         case 0x0d:
71             append(buffer, "%0D");
72             break;
73         case '"':
74             append(buffer, "%22");
75             break;
76         default:
77             append(buffer, c);
78         }
79     }
80 }
81 
encodingFromAcceptCharset(const String & acceptCharset,Document * document)82 TextEncoding FormDataBuilder::encodingFromAcceptCharset(const String& acceptCharset, Document* document)
83 {
84     String normalizedAcceptCharset = acceptCharset;
85     normalizedAcceptCharset.replace(',', ' ');
86 
87     Vector<String> charsets;
88     normalizedAcceptCharset.split(' ', charsets);
89 
90     TextEncoding encoding;
91 
92     Vector<String>::const_iterator end = charsets.end();
93     for (Vector<String>::const_iterator it = charsets.begin(); it != end; ++it) {
94         if ((encoding = TextEncoding(*it)).isValid())
95             return encoding;
96     }
97 
98     return document->inputEncoding();
99 }
100 
generateUniqueBoundaryString()101 Vector<char> FormDataBuilder::generateUniqueBoundaryString()
102 {
103     Vector<char> boundary;
104 
105     // The RFC 2046 spec says the alphanumeric characters plus the
106     // following characters are legal for boundaries:  '()+_,-./:=?
107     // However the following characters, though legal, cause some sites
108     // to fail: (),./:=+
109     // Note that our algorithm makes it twice as much likely for 'A' or 'B'
110     // to appear in the boundary string, because 0x41 and 0x42 are present in
111     // the below array twice.
112     static const char alphaNumericEncodingMap[64] = {
113         0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
114         0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50,
115         0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
116         0x59, 0x5A, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66,
117         0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E,
118         0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76,
119         0x77, 0x78, 0x79, 0x7A, 0x30, 0x31, 0x32, 0x33,
120         0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x41, 0x42
121     };
122 
123     // Start with an informative prefix.
124     append(boundary, "----WebKitFormBoundary");
125 
126     // Append 16 random 7bit ascii AlphaNumeric characters.
127     Vector<char> randomBytes;
128 
129     for (unsigned i = 0; i < 4; ++i) {
130         unsigned randomness = static_cast<unsigned>(randomNumber() * (std::numeric_limits<unsigned>::max() + 1.0));
131         randomBytes.append(alphaNumericEncodingMap[(randomness >> 24) & 0x3F]);
132         randomBytes.append(alphaNumericEncodingMap[(randomness >> 16) & 0x3F]);
133         randomBytes.append(alphaNumericEncodingMap[(randomness >> 8) & 0x3F]);
134         randomBytes.append(alphaNumericEncodingMap[randomness & 0x3F]);
135     }
136 
137     boundary.append(randomBytes);
138     boundary.append(0); // Add a 0 at the end so we can use this as a C-style string.
139     return boundary;
140 }
141 
beginMultiPartHeader(Vector<char> & buffer,const CString & boundary,const CString & name)142 void FormDataBuilder::beginMultiPartHeader(Vector<char>& buffer, const CString& boundary, const CString& name)
143 {
144     addBoundaryToMultiPartHeader(buffer, boundary);
145 
146     // FIXME: This loses data irreversibly if the input name includes characters you can't encode
147     // in the website's character set.
148     append(buffer, "Content-Disposition: form-data; name=\"");
149     appendQuotedString(buffer, name);
150     append(buffer, '"');
151 }
152 
addBoundaryToMultiPartHeader(Vector<char> & buffer,const CString & boundary,bool isLastBoundary)153 void FormDataBuilder::addBoundaryToMultiPartHeader(Vector<char>& buffer, const CString& boundary, bool isLastBoundary)
154 {
155     append(buffer, "--");
156     append(buffer, boundary);
157 
158     if (isLastBoundary)
159         append(buffer, "--");
160 
161     append(buffer, "\r\n");
162 }
163 
addFilenameToMultiPartHeader(Vector<char> & buffer,const TextEncoding & encoding,const String & filename)164 void FormDataBuilder::addFilenameToMultiPartHeader(Vector<char>& buffer, const TextEncoding& encoding, const String& filename)
165 {
166     // FIXME: This loses data irreversibly if the filename includes characters you can't encode
167     // in the website's character set.
168     append(buffer, "; filename=\"");
169     appendQuotedString(buffer, encoding.encode(filename.characters(), filename.length(), QuestionMarksForUnencodables));
170     append(buffer, '"');
171 }
172 
addContentTypeToMultiPartHeader(Vector<char> & buffer,const CString & mimeType)173 void FormDataBuilder::addContentTypeToMultiPartHeader(Vector<char>& buffer, const CString& mimeType)
174 {
175     append(buffer, "\r\nContent-Type: ");
176     append(buffer, mimeType);
177 }
178 
finishMultiPartHeader(Vector<char> & buffer)179 void FormDataBuilder::finishMultiPartHeader(Vector<char>& buffer)
180 {
181     append(buffer, "\r\n\r\n");
182 }
183 
addKeyValuePairAsFormData(Vector<char> & buffer,const CString & key,const CString & value)184 void FormDataBuilder::addKeyValuePairAsFormData(Vector<char>& buffer, const CString& key, const CString& value)
185 {
186     if (!buffer.isEmpty())
187         append(buffer, '&');
188 
189     encodeStringAsFormData(buffer, key);
190     append(buffer, '=');
191     encodeStringAsFormData(buffer, value);
192 }
193 
encodeStringAsFormData(Vector<char> & buffer,const CString & string)194 void FormDataBuilder::encodeStringAsFormData(Vector<char>& buffer, const CString& string)
195 {
196     // Same safe characters as Netscape for compatibility.
197     static const char safeCharacters[] = "-._*";
198 
199     // http://www.w3.org/TR/html4/interact/forms.html#h-17.13.4.1
200     unsigned length = string.length();
201     for (unsigned i = 0; i < length; ++i) {
202         unsigned char c = string.data()[i];
203 
204         if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') || strchr(safeCharacters, c))
205             append(buffer, c);
206         else if (c == ' ')
207             append(buffer, '+');
208         else if (c == '\n' || (c == '\r' && (i + 1 >= length || string.data()[i + 1] != '\n')))
209             append(buffer, "%0D%0A");
210         else if (c != '\r') {
211             append(buffer, '%');
212             appendByteAsHex(c, buffer);
213         }
214     }
215 }
216 
217 }
218