AK: Add basic percent encoder/decoder (urlencode and urldecode)

AK/URLParser.cpp

@@ -0,0 +1,107 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. 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.
+ *
+ * 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 HOLDER 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 <AK/String.h>
+#include <AK/StringBuilder.h>
+#include <AK/StringUtils.h>
+#include <AK/URLParser.h>
+
+namespace AK {
+
+static bool is_ascii_hex_digit(u8 ch)
+{
+    return (ch >= '0' && ch <= '9') || (ch >= 'a' && ch <= 'f') || (ch >= 'A' && ch <= 'F');
+}
+
+String urldecode(const StringView& input)
+{
+    size_t cursor = 0;
+
+    auto peek = [&](size_t offset = 0) -> u8 {
+        if (cursor + offset >= input.length())
+            return 0;
+        return input[cursor + offset];
+    };
+
+    auto consume = [&] {
+        return input[cursor++];
+    };
+
+    StringBuilder builder;
+    while (cursor < input.length()) {
+        if (peek() != '%') {
+            builder.append(consume());
+            continue;
+        }
+        if (!is_ascii_hex_digit(peek(1)) && !is_ascii_hex_digit(peek(2))) {
+            builder.append(consume());
+            continue;
+        }
+        bool ok;
+        u8 byte_point = StringUtils::convert_to_uint_from_hex(input.substring_view(cursor + 1, 2), ok);
+        builder.append(byte_point);
+        consume();
+        consume();
+        consume();
+    }
+    return builder.to_string();
+}
+
+static inline bool in_c0_control_set(u32 c)
+{
+    return c <= 0x1f || c > '~';
+}
+
+static inline bool in_fragment_set(u32 c)
+{
+    return in_c0_control_set(c) || c == ' ' || c == '"' || c == '<' || c == '>' || c == '`';
+}
+
+static inline bool in_path_set(u32 c)
+{
+    return in_fragment_set(c) || c == '#' || c == '?' || c == '{' || c == '}';
+}
+
+static inline bool in_userinfo_set(u32 c)
+{
+    return in_path_set(c) || c == '/' || c == ':' || c == ';' || c == '=' || c == '@' || (c >= '[' && c <= '^') || c == '|';
+}
+
+String urlencode(const StringView& input)
+{
+    StringBuilder builder;
+    for (char ch : input) {
+        if (in_userinfo_set((u8)ch)) {
+            builder.append('%');
+            builder.appendf("%02X", (u8)ch);
+        } else {
+            builder.append(ch);
+        }
+    }
+    return builder.to_string();
+}
+
+}

AK/URLParser.h

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. 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.
+ *
+ * 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 HOLDER 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.
+ */
+
+#pragma once
+
+#include <AK/Forward.h>
+
+namespace AK {
+
+String urlencode(const StringView&);
+String urldecode(const StringView&);
+
+}
+
+using AK::urldecode;
+using AK::urlencode;