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// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/uri.h"
#include <vector>
#include "src/char-predicates-inl.h"
#include "src/isolate-inl.h"
#include "src/string-search.h"
#include "src/unicode-inl.h"
namespace v8 {
namespace internal {
namespace { // anonymous namespace for DecodeURI helper functions
bool IsReservedPredicate(uc16 c) {
switch (c) {
case '#':
case '$':
case '&':
case '+':
case ',':
case '/':
case ':':
case ';':
case '=':
case '?':
case '@':
return true;
default:
return false;
}
}
bool IsReplacementCharacter(const uint8_t* octets, int length) {
// The replacement character is at codepoint U+FFFD in the Unicode Specials
// table. Its UTF-8 encoding is 0xEF 0xBF 0xBD.
if (length != 3 || octets[0] != 0xEF || octets[1] != 0xBF ||
octets[2] != 0xBD) {
return false;
}
return true;
}
bool DecodeOctets(const uint8_t* octets, int length,
std::vector<uc16>* buffer) {
size_t cursor = 0;
uc32 value = unibrow::Utf8::ValueOf(octets, length, &cursor);
if (value == unibrow::Utf8::kBadChar &&
!IsReplacementCharacter(octets, length)) {
return false;
}
if (value <= static_cast<uc32>(unibrow::Utf16::kMaxNonSurrogateCharCode)) {
buffer->push_back(value);
} else {
buffer->push_back(unibrow::Utf16::LeadSurrogate(value));
buffer->push_back(unibrow::Utf16::TrailSurrogate(value));
}
return true;
}
int TwoDigitHex(uc16 character1, uc16 character2) {
if (character1 > 'f') return -1;
int high = HexValue(character1);
if (high == -1) return -1;
if (character2 > 'f') return -1;
int low = HexValue(character2);
if (low == -1) return -1;
return (high << 4) + low;
}
template <typename T>
void AddToBuffer(uc16 decoded, String::FlatContent* uri_content, int index,
bool is_uri, std::vector<T>* buffer) {
if (is_uri && IsReservedPredicate(decoded)) {
buffer->push_back('%');
uc16 first = uri_content->Get(index + 1);
uc16 second = uri_content->Get(index + 2);
DCHECK_GT(std::numeric_limits<T>::max(), first);
DCHECK_GT(std::numeric_limits<T>::max(), second);
buffer->push_back(first);
buffer->push_back(second);
} else {
buffer->push_back(decoded);
}
}
bool IntoTwoByte(int index, bool is_uri, int uri_length,
String::FlatContent* uri_content, std::vector<uc16>* buffer) {
for (int k = index; k < uri_length; k++) {
uc16 code = uri_content->Get(k);
if (code == '%') {
int two_digits;
if (k + 2 >= uri_length ||
(two_digits = TwoDigitHex(uri_content->Get(k + 1),
uri_content->Get(k + 2))) < 0) {
return false;
}
k += 2;
uc16 decoded = static_cast<uc16>(two_digits);
if (decoded > unibrow::Utf8::kMaxOneByteChar) {
uint8_t octets[unibrow::Utf8::kMaxEncodedSize];
octets[0] = decoded;
int number_of_continuation_bytes = 0;
while ((decoded << ++number_of_continuation_bytes) & 0x80) {
if (number_of_continuation_bytes > 3 || k + 3 >= uri_length) {
return false;
}
if (uri_content->Get(++k) != '%' ||
(two_digits = TwoDigitHex(uri_content->Get(k + 1),
uri_content->Get(k + 2))) < 0) {
return false;
}
k += 2;
uc16 continuation_byte = static_cast<uc16>(two_digits);
octets[number_of_continuation_bytes] = continuation_byte;
}
if (!DecodeOctets(octets, number_of_continuation_bytes, buffer)) {
return false;
}
} else {
AddToBuffer(decoded, uri_content, k - 2, is_uri, buffer);
}
} else {
buffer->push_back(code);
}
}
return true;
}
bool IntoOneAndTwoByte(Handle<String> uri, bool is_uri,
std::vector<uint8_t>* one_byte_buffer,
std::vector<uc16>* two_byte_buffer) {
DisallowHeapAllocation no_gc;
String::FlatContent uri_content = uri->GetFlatContent();
int uri_length = uri->length();
for (int k = 0; k < uri_length; k++) {
uc16 code = uri_content.Get(k);
if (code == '%') {
int two_digits;
if (k + 2 >= uri_length ||
(two_digits = TwoDigitHex(uri_content.Get(k + 1),
uri_content.Get(k + 2))) < 0) {
return false;
}
uc16 decoded = static_cast<uc16>(two_digits);
if (decoded > unibrow::Utf8::kMaxOneByteChar) {
return IntoTwoByte(k, is_uri, uri_length, &uri_content,
two_byte_buffer);
}
AddToBuffer(decoded, &uri_content, k, is_uri, one_byte_buffer);
k += 2;
} else {
if (code > unibrow::Utf8::kMaxOneByteChar) {
return IntoTwoByte(k, is_uri, uri_length, &uri_content,
two_byte_buffer);
}
one_byte_buffer->push_back(code);
}
}
return true;
}
} // anonymous namespace
MaybeHandle<String> Uri::Decode(Isolate* isolate, Handle<String> uri,
bool is_uri) {
uri = String::Flatten(isolate, uri);
std::vector<uint8_t> one_byte_buffer;
std::vector<uc16> two_byte_buffer;
if (!IntoOneAndTwoByte(uri, is_uri, &one_byte_buffer, &two_byte_buffer)) {
THROW_NEW_ERROR(isolate, NewURIError(), String);
}
if (two_byte_buffer.empty()) {
return isolate->factory()->NewStringFromOneByte(Vector<const uint8_t>(
one_byte_buffer.data(), static_cast<int>(one_byte_buffer.size())));
}
Handle<SeqTwoByteString> result;
int result_length =
static_cast<int>(one_byte_buffer.size() + two_byte_buffer.size());
ASSIGN_RETURN_ON_EXCEPTION(
isolate, result, isolate->factory()->NewRawTwoByteString(result_length),
String);
CopyChars(result->GetChars(), one_byte_buffer.data(), one_byte_buffer.size());
CopyChars(result->GetChars() + one_byte_buffer.size(), two_byte_buffer.data(),
two_byte_buffer.size());
return result;
}
namespace { // anonymous namespace for EncodeURI helper functions
bool IsUnescapePredicateInUriComponent(uc16 c) {
if (IsAlphaNumeric(c)) {
return true;
}
switch (c) {
case '!':
case '\'':
case '(':
case ')':
case '*':
case '-':
case '.':
case '_':
case '~':
return true;
default:
return false;
}
}
bool IsUriSeparator(uc16 c) {
switch (c) {
case '#':
case ':':
case ';':
case '/':
case '?':
case '$':
case '&':
case '+':
case ',':
case '@':
case '=':
return true;
default:
return false;
}
}
void AddEncodedOctetToBuffer(uint8_t octet, std::vector<uint8_t>* buffer) {
buffer->push_back('%');
buffer->push_back(HexCharOfValue(octet >> 4));
buffer->push_back(HexCharOfValue(octet & 0x0F));
}
void EncodeSingle(uc16 c, std::vector<uint8_t>* buffer) {
char s[4] = {};
int number_of_bytes;
number_of_bytes =
unibrow::Utf8::Encode(s, c, unibrow::Utf16::kNoPreviousCharacter, false);
for (int k = 0; k < number_of_bytes; k++) {
AddEncodedOctetToBuffer(s[k], buffer);
}
}
void EncodePair(uc16 cc1, uc16 cc2, std::vector<uint8_t>* buffer) {
char s[4] = {};
int number_of_bytes =
unibrow::Utf8::Encode(s, unibrow::Utf16::CombineSurrogatePair(cc1, cc2),
unibrow::Utf16::kNoPreviousCharacter, false);
for (int k = 0; k < number_of_bytes; k++) {
AddEncodedOctetToBuffer(s[k], buffer);
}
}
} // anonymous namespace
MaybeHandle<String> Uri::Encode(Isolate* isolate, Handle<String> uri,
bool is_uri) {
uri = String::Flatten(isolate, uri);
int uri_length = uri->length();
std::vector<uint8_t> buffer;
buffer.reserve(uri_length);
{
DisallowHeapAllocation no_gc;
String::FlatContent uri_content = uri->GetFlatContent();
for (int k = 0; k < uri_length; k++) {
uc16 cc1 = uri_content.Get(k);
if (unibrow::Utf16::IsLeadSurrogate(cc1)) {
k++;
if (k < uri_length) {
uc16 cc2 = uri->Get(k);
if (unibrow::Utf16::IsTrailSurrogate(cc2)) {
EncodePair(cc1, cc2, &buffer);
continue;
}
}
} else if (!unibrow::Utf16::IsTrailSurrogate(cc1)) {
if (IsUnescapePredicateInUriComponent(cc1) ||
(is_uri && IsUriSeparator(cc1))) {
buffer.push_back(cc1);
} else {
EncodeSingle(cc1, &buffer);
}
continue;
}
AllowHeapAllocation allocate_error_and_return;
THROW_NEW_ERROR(isolate, NewURIError(), String);
}
}
return isolate->factory()->NewStringFromOneByte(
Vector<const uint8_t>(buffer.data(), static_cast<int>(buffer.size())));
}
namespace { // Anonymous namespace for Escape and Unescape
template <typename Char>
int UnescapeChar(Vector<const Char> vector, int i, int length, int* step) {
uint16_t character = vector[i];
int32_t hi = 0;
int32_t lo = 0;
if (character == '%' && i <= length - 6 && vector[i + 1] == 'u' &&
(hi = TwoDigitHex(vector[i + 2], vector[i + 3])) > -1 &&
(lo = TwoDigitHex(vector[i + 4], vector[i + 5])) > -1) {
*step = 6;
return (hi << 8) + lo;
} else if (character == '%' && i <= length - 3 &&
(lo = TwoDigitHex(vector[i + 1], vector[i + 2])) > -1) {
*step = 3;
return lo;
} else {
*step = 1;
return character;
}
}
template <typename Char>
MaybeHandle<String> UnescapeSlow(Isolate* isolate, Handle<String> string,
int start_index) {
bool one_byte = true;
int length = string->length();
int unescaped_length = 0;
{
DisallowHeapAllocation no_allocation;
Vector<const Char> vector = string->GetCharVector<Char>();
for (int i = start_index; i < length; unescaped_length++) {
int step;
if (UnescapeChar(vector, i, length, &step) >
String::kMaxOneByteCharCode) {
one_byte = false;
}
i += step;
}
}
DCHECK(start_index < length);
Handle<String> first_part =
isolate->factory()->NewProperSubString(string, 0, start_index);
int dest_position = 0;
Handle<String> second_part;
DCHECK_LE(unescaped_length, String::kMaxLength);
if (one_byte) {
Handle<SeqOneByteString> dest = isolate->factory()
->NewRawOneByteString(unescaped_length)
.ToHandleChecked();
DisallowHeapAllocation no_allocation;
Vector<const Char> vector = string->GetCharVector<Char>();
for (int i = start_index; i < length; dest_position++) {
int step;
dest->SeqOneByteStringSet(dest_position,
UnescapeChar(vector, i, length, &step));
i += step;
}
second_part = dest;
} else {
Handle<SeqTwoByteString> dest = isolate->factory()
->NewRawTwoByteString(unescaped_length)
.ToHandleChecked();
DisallowHeapAllocation no_allocation;
Vector<const Char> vector = string->GetCharVector<Char>();
for (int i = start_index; i < length; dest_position++) {
int step;
dest->SeqTwoByteStringSet(dest_position,
UnescapeChar(vector, i, length, &step));
i += step;
}
second_part = dest;
}
return isolate->factory()->NewConsString(first_part, second_part);
}
bool IsNotEscaped(uint16_t c) {
if (IsAlphaNumeric(c)) {
return true;
}
// @*_+-./
switch (c) {
case '@':
case '*':
case '_':
case '+':
case '-':
case '.':
case '/':
return true;
default:
return false;
}
}
template <typename Char>
static MaybeHandle<String> UnescapePrivate(Isolate* isolate,
Handle<String> source) {
int index;
{
DisallowHeapAllocation no_allocation;
StringSearch<uint8_t, Char> search(isolate, STATIC_CHAR_VECTOR("%"));
index = search.Search(source->GetCharVector<Char>(), 0);
if (index < 0) return source;
}
return UnescapeSlow<Char>(isolate, source, index);
}
template <typename Char>
static MaybeHandle<String> EscapePrivate(Isolate* isolate,
Handle<String> string) {
DCHECK(string->IsFlat());
int escaped_length = 0;
int length = string->length();
{
DisallowHeapAllocation no_allocation;
Vector<const Char> vector = string->GetCharVector<Char>();
for (int i = 0; i < length; i++) {
uint16_t c = vector[i];
if (c >= 256) {
escaped_length += 6;
} else if (IsNotEscaped(c)) {
escaped_length++;
} else {
escaped_length += 3;
}
// We don't allow strings that are longer than a maximal length.
DCHECK_LT(String::kMaxLength, 0x7FFFFFFF - 6); // Cannot overflow.
if (escaped_length > String::kMaxLength) break; // Provoke exception.
}
}
// No length change implies no change. Return original string if no change.
if (escaped_length == length) return string;
Handle<SeqOneByteString> dest;
ASSIGN_RETURN_ON_EXCEPTION(
isolate, dest, isolate->factory()->NewRawOneByteString(escaped_length),
String);
int dest_position = 0;
{
DisallowHeapAllocation no_allocation;
Vector<const Char> vector = string->GetCharVector<Char>();
for (int i = 0; i < length; i++) {
uint16_t c = vector[i];
if (c >= 256) {
dest->SeqOneByteStringSet(dest_position, '%');
dest->SeqOneByteStringSet(dest_position + 1, 'u');
dest->SeqOneByteStringSet(dest_position + 2, HexCharOfValue(c >> 12));
dest->SeqOneByteStringSet(dest_position + 3,
HexCharOfValue((c >> 8) & 0xF));
dest->SeqOneByteStringSet(dest_position + 4,
HexCharOfValue((c >> 4) & 0xF));
dest->SeqOneByteStringSet(dest_position + 5, HexCharOfValue(c & 0xF));
dest_position += 6;
} else if (IsNotEscaped(c)) {
dest->SeqOneByteStringSet(dest_position, c);
dest_position++;
} else {
dest->SeqOneByteStringSet(dest_position, '%');
dest->SeqOneByteStringSet(dest_position + 1, HexCharOfValue(c >> 4));
dest->SeqOneByteStringSet(dest_position + 2, HexCharOfValue(c & 0xF));
dest_position += 3;
}
}
}
return dest;
}
} // Anonymous namespace
MaybeHandle<String> Uri::Escape(Isolate* isolate, Handle<String> string) {
Handle<String> result;
string = String::Flatten(isolate, string);
return string->IsOneByteRepresentationUnderneath()
? EscapePrivate<uint8_t>(isolate, string)
: EscapePrivate<uc16>(isolate, string);
}
MaybeHandle<String> Uri::Unescape(Isolate* isolate, Handle<String> string) {
Handle<String> result;
string = String::Flatten(isolate, string);
return string->IsOneByteRepresentationUnderneath()
? UnescapePrivate<uint8_t>(isolate, string)
: UnescapePrivate<uc16>(isolate, string);
}
} // namespace internal
} // namespace v8
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