ladybird/AK/URL.cpp

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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2021, Max Wipfli <mail@maxwipfli.ch>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Debug.h>
#include <AK/LexicalPath.h>
#include <AK/StringBuilder.h>
#include <AK/URL.h>
#include <AK/URLParser.h>
#include <AK/Utf8View.h>
namespace AK {
constexpr bool is_ascii_alpha(u32 code_point)
{
return ('a' <= code_point && code_point <= 'z') || ('A' <= code_point && code_point <= 'Z');
}
constexpr bool is_ascii_digit(u32 code_point)
{
return '0' <= code_point && code_point <= '9';
}
constexpr bool is_ascii_alphanumeric(u32 code_point)
{
return is_ascii_alpha(code_point) || is_ascii_digit(code_point);
}
constexpr bool is_ascii_hex_digit(u32 code_point)
{
return is_ascii_digit(code_point) || (code_point >= 'a' && code_point <= 'f') || (code_point >= 'A' && code_point <= 'F');
}
// FIXME: It could make sense to force users of URL to use URLParser::parse() explicitly instead of using a constructor.
URL::URL(StringView const& string)
: URL(URLParser::parse({}, string))
{
if constexpr (URL_PARSER_DEBUG) {
if (m_valid)
dbgln("URL constructor: Parsed URL to be '{}'.", serialize());
else
dbgln("URL constructor: Parsed URL to be invalid.");
}
}
String URL::path() const
{
if (cannot_be_a_base_url())
return paths()[0];
StringBuilder builder;
for (auto& path : m_paths) {
builder.append('/');
builder.append(path);
}
return builder.to_string();
}
URL URL::complete_url(String const& string) const
{
if (!is_valid())
return {};
return URLParser::parse({}, string, this);
}
void URL::set_scheme(String scheme)
{
m_scheme = move(scheme);
m_valid = compute_validity();
}
void URL::set_username(String username)
{
m_username = move(username);
m_valid = compute_validity();
}
void URL::set_password(String password)
{
m_password = move(password);
m_valid = compute_validity();
}
void URL::set_host(String host)
{
m_host = move(host);
m_valid = compute_validity();
}
void URL::set_port(u16 port)
{
if (port == default_port_for_scheme(m_scheme)) {
m_port = 0;
return;
}
m_port = port;
m_valid = compute_validity();
}
void URL::set_paths(Vector<String> paths)
{
m_paths = move(paths);
m_valid = compute_validity();
}
void URL::set_query(String query)
{
m_query = move(query);
}
void URL::set_fragment(String fragment)
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{
m_fragment = move(fragment);
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}
// FIXME: This is by no means complete.
// NOTE: This relies on some assumptions about how the spec-defined URL parser works that may turn out to be wrong.
bool URL::compute_validity() const
{
if (m_scheme.is_empty())
return false;
if (m_scheme == "data") {
if (m_data_mime_type.is_empty())
return false;
if (m_data_payload_is_base64) {
if (m_data_payload.length() % 4 != 0)
return false;
for (auto character : m_data_payload) {
if (!is_ascii_alphanumeric(character) || character == '+' || character == '/' || character == '=')
return false;
}
}
} else if (m_cannot_be_a_base_url) {
if (m_paths.size() != 1)
return false;
if (m_paths[0].is_empty())
return false;
} else {
if (m_scheme.is_one_of("about", "mailto"))
return false;
// NOTE: Maybe it is allowed to have a zero-segment path.
if (m_paths.size() == 0)
return false;
}
// NOTE: A file URL's host should be the empty string for localhost, not null.
if (m_scheme == "file" && m_host.is_null())
return false;
return true;
}
bool URL::scheme_requires_port(StringView const& scheme)
{
return (default_port_for_scheme(scheme) != 0);
}
u16 URL::default_port_for_scheme(StringView const& scheme)
{
if (scheme == "http")
return 80;
if (scheme == "https")
return 443;
if (scheme == "gemini")
return 1965;
if (scheme == "irc")
return 6667;
if (scheme == "ircs")
return 6697;
if (scheme == "ws")
return 80;
if (scheme == "wss")
return 443;
return 0;
}
URL URL::create_with_file_scheme(String const& path, String const& fragment, String const& hostname)
{
LexicalPath lexical_path(path);
if (!lexical_path.is_valid() || !lexical_path.is_absolute())
return {};
URL url;
url.set_scheme("file");
// NOTE: If the hostname is localhost (or null, which implies localhost), it should be set to the empty string.
// This is because a file URL always needs a non-null hostname.
url.set_host(hostname.is_null() || hostname == "localhost" ? String::empty() : hostname);
url.set_paths(lexical_path.parts());
// NOTE: To indicate that we want to end the path with a slash, we have to append an empty path segment.
if (path.ends_with('/'))
url.append_path("");
url.set_fragment(fragment);
return url;
}
URL URL::create_with_url_or_path(String const& url_or_path)
{
URL url = url_or_path;
if (url.is_valid())
return url;
String path = LexicalPath::canonicalized_path(url_or_path);
return URL::create_with_file_scheme(path);
}
// https://url.spec.whatwg.org/#special-scheme
bool URL::is_special_scheme(StringView const& scheme)
{
return scheme.is_one_of("ftp", "file", "http", "https", "ws", "wss");
}
String URL::serialize_data_url() const
{
VERIFY(m_scheme == "data");
VERIFY(!m_data_mime_type.is_null());
VERIFY(!m_data_payload.is_null());
StringBuilder builder;
builder.append(m_scheme);
builder.append(':');
builder.append(m_data_mime_type);
if (m_data_payload_is_base64)
builder.append(";base64");
builder.append(',');
// NOTE: The specification does not say anything about encoding this, but we should encode at least control and non-ASCII
// characters (since this is also a valid representation of the same data URL).
builder.append(URL::percent_encode(m_data_payload, PercentEncodeSet::C0Control));
return builder.to_string();
}
// https://url.spec.whatwg.org/#concept-url-serializer
String URL::serialize(ExcludeFragment exclude_fragment) const
{
if (m_scheme == "data")
return serialize_data_url();
StringBuilder builder;
builder.append(m_scheme);
builder.append(':');
if (!m_host.is_null()) {
builder.append("//");
if (includes_credentials()) {
builder.append(percent_encode(m_username, PercentEncodeSet::Userinfo));
if (!m_password.is_empty()) {
builder.append(':');
builder.append(percent_encode(m_password, PercentEncodeSet::Userinfo));
}
builder.append('@');
}
builder.append(m_host);
if (m_port != 0)
builder.appendff(":{}", m_port);
}
if (cannot_be_a_base_url()) {
builder.append(percent_encode(m_paths[0], PercentEncodeSet::Path));
} else {
if (m_host.is_null() && m_paths.size() > 1 && m_paths[0].is_empty())
builder.append("/.");
for (auto& segment : m_paths) {
builder.append('/');
builder.append(percent_encode(segment, PercentEncodeSet::Path));
}
}
if (!m_query.is_null()) {
builder.append('?');
builder.append(percent_encode(m_query, is_special() ? URL::PercentEncodeSet::SpecialQuery : URL::PercentEncodeSet::Query));
}
if (exclude_fragment == ExcludeFragment::No && !m_fragment.is_null()) {
builder.append('#');
builder.append(percent_encode(m_fragment, PercentEncodeSet::Fragment));
}
return builder.to_string();
}
// https://url.spec.whatwg.org/#url-rendering
// NOTE: This does e.g. not display credentials.
// FIXME: Parts of the URL other than the host should have their sequences of percent-encoded bytes replaced with code points
// resulting from percent-decoding those sequences converted to bytes, unless that renders those sequences invisible.
String URL::serialize_for_display() const
{
VERIFY(m_valid);
if (m_scheme == "data")
return serialize_data_url();
StringBuilder builder;
builder.append(m_scheme);
builder.append(':');
if (!m_host.is_null()) {
builder.append("//");
builder.append(m_host);
if (m_port != 0)
builder.appendff(":{}", m_port);
}
if (cannot_be_a_base_url()) {
builder.append(percent_encode(m_paths[0], PercentEncodeSet::Path));
} else {
if (m_host.is_null() && m_paths.size() > 1 && m_paths[0].is_empty())
builder.append("/.");
for (auto& segment : m_paths) {
builder.append('/');
builder.append(percent_encode(segment, PercentEncodeSet::Path));
}
}
if (!m_query.is_null()) {
builder.append('?');
builder.append(percent_encode(m_query, is_special() ? URL::PercentEncodeSet::SpecialQuery : URL::PercentEncodeSet::Query));
}
if (!m_fragment.is_null()) {
builder.append('#');
builder.append(percent_encode(m_fragment, PercentEncodeSet::Fragment));
}
return builder.to_string();
}
bool URL::equals(URL const& other, ExcludeFragment exclude_fragments) const
{
if (!m_valid || !other.m_valid)
return false;
return serialize(exclude_fragments) == other.serialize(exclude_fragments);
}
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String URL::basename() const
{
if (!m_valid)
return {};
if (m_paths.is_empty())
return {};
return m_paths.last();
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}
void URL::append_percent_encoded(StringBuilder& builder, u32 code_point)
{
if (code_point <= 0x7f)
builder.appendff("%{:02X}", code_point);
else if (code_point <= 0x07ff)
builder.appendff("%{:02X}%{:02X}", ((code_point >> 6) & 0x1f) | 0xc0, (code_point & 0x3f) | 0x80);
else if (code_point <= 0xffff)
builder.appendff("%{:02X}%{:02X}%{:02X}", ((code_point >> 12) & 0x0f) | 0xe0, ((code_point >> 6) & 0x3f) | 0x80, (code_point & 0x3f) | 0x80);
else if (code_point <= 0x10ffff)
builder.appendff("%{:02X}%{:02X}%{:02X}%{:02X}", ((code_point >> 18) & 0x07) | 0xf0, ((code_point >> 12) & 0x3f) | 0x80, ((code_point >> 6) & 0x3f) | 0x80, (code_point & 0x3f) | 0x80);
else
VERIFY_NOT_REACHED();
}
// https://url.spec.whatwg.org/#c0-control-percent-encode-set
constexpr bool code_point_is_in_percent_encode_set(u32 code_point, URL::PercentEncodeSet set)
{
switch (set) {
case URL::PercentEncodeSet::C0Control:
return code_point < 0x20 || code_point > 0x7E;
case URL::PercentEncodeSet::Fragment:
return code_point_is_in_percent_encode_set(code_point, URL::PercentEncodeSet::C0Control) || " \"<>`"sv.contains(code_point);
case URL::PercentEncodeSet::Query:
return code_point_is_in_percent_encode_set(code_point, URL::PercentEncodeSet::C0Control) || " \"#<>"sv.contains(code_point);
case URL::PercentEncodeSet::SpecialQuery:
return code_point_is_in_percent_encode_set(code_point, URL::PercentEncodeSet::Query) || code_point == '\'';
case URL::PercentEncodeSet::Path:
return code_point_is_in_percent_encode_set(code_point, URL::PercentEncodeSet::Query) || "?`{}"sv.contains(code_point);
case URL::PercentEncodeSet::Userinfo:
return code_point_is_in_percent_encode_set(code_point, URL::PercentEncodeSet::Path) || "/:;=@[\\]^|"sv.contains(code_point);
case URL::PercentEncodeSet::Component:
return code_point_is_in_percent_encode_set(code_point, URL::PercentEncodeSet::Userinfo) || "$%&+,"sv.contains(code_point);
case URL::PercentEncodeSet::ApplicationXWWWFormUrlencoded:
return code_point >= 0x7E || !(is_ascii_alphanumeric(code_point) || "!'()~"sv.contains(code_point));
case URL::PercentEncodeSet::EncodeURI:
// NOTE: This is the same percent encode set that JS encodeURI() uses.
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/encodeURI
return code_point >= 0x7E || (!is_ascii_alphanumeric(code_point) && !";,/?:@&=+$-_.!~*'()#"sv.contains(code_point));
default:
VERIFY_NOT_REACHED();
}
}
void URL::append_percent_encoded_if_necessary(StringBuilder& builder, u32 code_point, URL::PercentEncodeSet set)
{
if (code_point_is_in_percent_encode_set(code_point, set))
append_percent_encoded(builder, code_point);
else
builder.append_code_point(code_point);
}
String URL::percent_encode(StringView const& input, URL::PercentEncodeSet set)
{
StringBuilder builder;
for (auto code_point : Utf8View(input)) {
append_percent_encoded_if_necessary(builder, code_point, set);
}
return builder.to_string();
}
constexpr u8 parse_hex_digit(u8 digit)
{
if (digit >= '0' && digit <= '9')
return digit - '0';
if (digit >= 'a' && digit <= 'f')
return digit - 'a' + 10;
if (digit >= 'A' && digit <= 'F')
return digit - 'A' + 10;
VERIFY_NOT_REACHED();
}
String URL::percent_decode(StringView const& input)
{
if (!input.contains('%'))
return input;
StringBuilder builder;
Utf8View utf8_view(input);
for (auto it = utf8_view.begin(); !it.done(); ++it) {
if (*it != '%') {
builder.append_code_point(*it);
} else if (!is_ascii_hex_digit(it.peek(1).value_or(0)) || !is_ascii_hex_digit(it.peek(2).value_or(0))) {
builder.append_code_point(*it);
} else {
++it;
u8 byte = parse_hex_digit(*it) << 4;
++it;
byte += parse_hex_digit(*it);
builder.append(byte);
}
}
return builder.to_string();
}
}