com.chiorichan.http.CookieDecoder.java Source code

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Here is the source code for com.chiorichan.http.CookieDecoder.java

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/**
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * Copyright 2016 Chiori Greene a.k.a. Chiori-chan <me@chiorichan.com>
 * All Right Reserved.
 */
package com.chiorichan.http;

import io.netty.handler.codec.http.Cookie;
import io.netty.handler.codec.http.DefaultCookie;
import io.netty.handler.codec.http.ServerCookieEncoder;
import io.netty.util.internal.InternalThreadLocalMap;

import java.util.Collections;
import java.util.Set;
import java.util.TreeSet;

/**
 * A <a href="http://tools.ietf.org/html/rfc6265">RFC6265</a> compliant cookie decoder to be used server side
 * with modification to fix a few issues we were having..
 *
 * Only name and value fields are expected, so old fields are not populated (path, domain, etc).
 *
 * Old <a href="http://tools.ietf.org/html/rfc2965">RFC2965</a> cookies are still supported,
 * old fields will simply be ignored.
 *
 * @see ServerCookieEncoder
 */
public final class CookieDecoder {
    private CookieDecoder() {
        // unused
    }

    /**
     * Decodes the specified Set-Cookie HTTP header value into a {@link Cookie}.
     *
     * @return the decoded {@link Cookie}
     */
    public static Set<Cookie> decode(String header) {

        if (header == null)
            throw new NullPointerException("header");

        final int headerLen = header.length();

        if (headerLen == 0)
            return Collections.emptySet();

        Set<Cookie> cookies = new TreeSet<Cookie>();

        int i = 0;

        boolean rfc2965Style = false;
        if (header.regionMatches(true, 0, "$Version", 0, 8)) {
            // RFC 2965 style cookie, move to after version value
            i = header.indexOf(';') + 1;
            rfc2965Style = true;
        }

        loop: for (;;) {

            // Skip spaces and separators.
            for (;;) {
                if (i == headerLen)
                    break loop;
                char c = header.charAt(i);
                if (c == '\t' || c == '\n' || c == 0x0b || c == '\f' || c == '\r' || c == ' ' || c == ','
                        || c == ';') {
                    i++;
                    continue;
                }
                break;
            }

            int newNameStart = i;
            int newNameEnd = i;
            String value;

            if (i == headerLen)
                value = null;
            else
                keyValLoop: for (;;) {
                    char curChar = header.charAt(i);
                    if (curChar == ';') {
                        // NAME; (no value till ';')
                        newNameEnd = i;
                        value = null;
                        break keyValLoop;
                    } else if (curChar == '=') {
                        // NAME=VALUE
                        newNameEnd = i;
                        i++;
                        if (i == headerLen) {
                            // NAME= (empty value, i.e. nothing after '=')
                            value = "";
                            break keyValLoop;
                        }

                        int newValueStart = i;
                        char c = header.charAt(i);
                        if (c == '"') {
                            // NAME="VALUE"
                            StringBuilder newValueBuf = InternalThreadLocalMap.get().stringBuilder();

                            final char q = c;
                            boolean hadBackslash = false;
                            i++;
                            for (;;) {
                                if (i == headerLen) {
                                    value = newValueBuf.toString();
                                    break keyValLoop;
                                }
                                if (hadBackslash) {
                                    hadBackslash = false;
                                    c = header.charAt(i++);
                                    if (c == '\\' || c == '"')
                                        // Escape last backslash.
                                        newValueBuf.setCharAt(newValueBuf.length() - 1, c);
                                    else
                                        // Do not escape last backslash.
                                        newValueBuf.append(c);
                                } else {
                                    c = header.charAt(i++);
                                    if (c == q) {
                                        value = newValueBuf.toString();
                                        break keyValLoop;
                                    }
                                    newValueBuf.append(c);
                                    if (c == '\\')
                                        hadBackslash = true;
                                }
                            }
                        } else {
                            // NAME=VALUE;
                            int semiPos = header.indexOf(';', i);
                            if (semiPos > 0) {
                                value = header.substring(newValueStart, semiPos);
                                i = semiPos;
                            } else {
                                value = header.substring(newValueStart);
                                i = headerLen;
                            }
                        }
                        break keyValLoop;
                    } else
                        i++;

                    if (i == headerLen) {
                        // NAME (no value till the end of string)
                        newNameEnd = headerLen;
                        value = null;
                        break;
                    }
                }

            if (!rfc2965Style || (!header.regionMatches(newNameStart, "$Path", 0, "$Path".length())
                    && !header.regionMatches(newNameStart, "$Domain", 0, "$Domain".length())
                    && !header.regionMatches(newNameStart, "$Port", 0, "$Port".length()))) {

                // skip obsolete RFC2965 fields
                String name = header.substring(newNameStart, newNameEnd);
                cookies.add(new DefaultCookie(name, value));
            }
        }

        return cookies;
    }
}