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Diffstat (limited to 'googleurl/url_canon_query.cpp')
| -rw-r--r-- | googleurl/url_canon_query.cpp | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/googleurl/url_canon_query.cpp b/googleurl/url_canon_query.cpp new file mode 100644 index 0000000..d52d7c7 --- /dev/null +++ b/googleurl/url_canon_query.cpp @@ -0,0 +1,189 @@ +// Copyright 2007, Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#include "url_canon.h" +#include "url_canon_internal.h" + +// Query canonicalization in IE +// ---------------------------- +// IE is very permissive for query parameters specified in links on the page +// (in contrast to links that it constructs itself based on form data). It does +// not unescape any character. It does not reject any escape sequence (be they +// invalid like "%2y" or freaky like %00). +// +// IE only escapes spaces and nothing else. Embedded NULLs, tabs (0x09), +// LF (0x0a), and CR (0x0d) are removed (this probably happens at an earlier +// layer since they are removed from all portions of the URL). All other +// characters are passed unmodified. Invalid UTF-16 sequences are preserved as +// well, with each character in the input being converted to UTF-8. It is the +// server's job to make sense of this invalid query. +// +// Invalid multibyte sequences (for example, invalid UTF-8 on a UTF-8 page) +// are converted to the invalid character and sent as unescaped UTF-8 (0xef, +// 0xbf, 0xbd). This may not be canonicalization, the parser may generate these +// strings before the URL handler ever sees them. +// +// Our query canonicalization +// -------------------------- +// We escape all non-ASCII characters and control characters, like Firefox. +// This is more conformant to the URL spec, and there do not seem to be many +// problems relating to Firefox's behavior. +// +// Like IE, we will never unescape (although the application may want to try +// unescaping to present the user with a more understandable URL). We will +// replace all invalid sequences (including invalid UTF-16 sequences, which IE +// doesn't) with the "invalid character," and we will escape it. + +namespace url_canon { + +namespace { + +// Returns true if the characters starting at |begin| and going until |end| +// (non-inclusive) are all representable in 7-bits. +template<typename CHAR, typename UCHAR> +bool IsAllASCII(const CHAR* spec, const url_parse::Component& query) { + int end = query.end(); + for (int i = query.begin; i < end; i++) { + if (static_cast<UCHAR>(spec[i]) >= 0x80) + return false; + } + return true; +} + +// Appends the given string to the output, escaping characters that do not +// match the given |type| in SharedCharTypes. This version will accept 8 or 16 +// bit characters, but assumes that they have only 7-bit values. It also assumes +// that all UTF-8 values are correct, so doesn't bother checking +template<typename CHAR> +void AppendRaw8BitQueryString(const CHAR* source, int length, + CanonOutput* output) { + for (int i = 0; i < length; i++) { + if (!IsQueryChar(static_cast<unsigned char>(source[i]))) + AppendEscapedChar(static_cast<unsigned char>(source[i]), output); + else // Doesn't need escaping. + output->push_back(static_cast<char>(source[i])); + } +} + +// Runs the converter on the given UTF-8 input. Since the converter expects +// UTF-16, we have to convert first. The converter must be non-NULL. +void RunConverter(const char* spec, + const url_parse::Component& query, + CharsetConverter* converter, + CanonOutput* output) { + // This function will replace any misencoded values with the invalid + // character. This is what we want so we don't have to check for error. + RawCanonOutputW<1024> utf16; + ConvertUTF8ToUTF16(&spec[query.begin], query.len, &utf16); + converter->ConvertFromUTF16(utf16.data(), utf16.length(), output); +} + +// Runs the converter with the given UTF-16 input. We don't have to do +// anything, but this overriddden function allows us to use the same code +// for both UTF-8 and UTF-16 input. +void RunConverter(const char16* spec, + const url_parse::Component& query, + CharsetConverter* converter, + CanonOutput* output) { + converter->ConvertFromUTF16(&spec[query.begin], query.len, output); +} + +template<typename CHAR, typename UCHAR> +void DoConvertToQueryEncoding(const CHAR* spec, + const url_parse::Component& query, + CharsetConverter* converter, + CanonOutput* output) { + if (IsAllASCII<CHAR, UCHAR>(spec, query)) { + // Easy: the input can just appended with no character set conversions. + AppendRaw8BitQueryString(&spec[query.begin], query.len, output); + + } else { + // Harder: convert to the proper encoding first. + if (converter) { + // Run the converter to get an 8-bit string, then append it, escaping + // necessary values. + RawCanonOutput<1024> eight_bit; + RunConverter(spec, query, converter, &eight_bit); + AppendRaw8BitQueryString(eight_bit.data(), eight_bit.length(), output); + + } else { + // No converter, do our own UTF-8 conversion. + AppendStringOfType(&spec[query.begin], query.len, CHAR_QUERY, output); + } + } +} + +template<typename CHAR, typename UCHAR> +void DoCanonicalizeQuery(const CHAR* spec, + const url_parse::Component& query, + CharsetConverter* converter, + CanonOutput* output, + url_parse::Component* out_query) { + if (query.len < 0) { + *out_query = url_parse::Component(); + return; + } + + output->push_back('?'); + out_query->begin = output->length(); + + DoConvertToQueryEncoding<CHAR, UCHAR>(spec, query, converter, output); + + out_query->len = output->length() - out_query->begin; +} + +} // namespace + +void CanonicalizeQuery(const char* spec, + const url_parse::Component& query, + CharsetConverter* converter, + CanonOutput* output, + url_parse::Component* out_query) { + DoCanonicalizeQuery<char, unsigned char>(spec, query, converter, + output, out_query); +} + +void CanonicalizeQuery(const char16* spec, + const url_parse::Component& query, + CharsetConverter* converter, + CanonOutput* output, + url_parse::Component* out_query) { + DoCanonicalizeQuery<char16, char16>(spec, query, converter, + output, out_query); +} + +void ConvertUTF16ToQueryEncoding(const char16* input, + const url_parse::Component& query, + CharsetConverter* converter, + CanonOutput* output) { + DoConvertToQueryEncoding<char16, char16>(input, query, + converter, output); +} + +} // namespace url_canon |