    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      https://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.validator;
    018
    019import java.io.Serializable;
    020import java.util.Arrays;
    021import java.util.HashSet;
    022import java.util.Set;
    023import java.util.regex.Matcher;
    024import java.util.regex.Pattern;
    025
    026import org.apache.commons.validator.routines.InetAddressValidator;
    027import org.apache.commons.validator.util.Flags;
    028
    029/**
    030 * Validates URLs.
    031 * Behaviour of validation is modified by passing in options:
    032 * <ul>
    033 * <li>ALLOW_2_SLASHES - [FALSE]  Allows double '/' characters in the path
    034 * component.</li>
    035 * <li>NO_FRAGMENT- [FALSE]  By default fragments are allowed, if this option is
    036 * included then fragments are flagged as illegal.</li>
    037 * <li>ALLOW_ALL_SCHEMES - [FALSE] By default only http, https, and ftp are
    038 * considered valid schemes.  Enabling this option will let any scheme pass validation.</li>
    039 * </ul>
    040 *
    041 * <p>Originally based in on php script by Debbie Dyer, validation.php v1.2b, Date: 03/07/02,
    042 * https://javascript.internet.com. However, this validation now bears little resemblance
    043 * to the php original.</p>
    044 * <pre>
    045 *   Example of usage:
    046 *   Construct a UrlValidator with valid schemes of "http", and "https".
    047 *
    048 *    String[] schemes = {"http","https"}.
    049 *    UrlValidator urlValidator = new UrlValidator(schemes);
    050 *    if (urlValidator.isValid("ftp://foo.bar.com/")) {
    051 *       System.out.println("URL is valid");
    052 *    } else {
    053 *       System.out.println("URL is invalid");
    054 *    }
    055 *
    056 *    prints "URL is invalid"
    057 *   If instead the default constructor is used.
    058 *
    059 *    UrlValidator urlValidator = new UrlValidator();
    060 *    if (urlValidator.isValid("ftp://foo.bar.com/")) {
    061 *       System.out.println("URL is valid");
    062 *    } else {
    063 *       System.out.println("URL is invalid");
    064 *    }
    065 *
    066 *   prints out "URL is valid"
    067 *  </pre>
    068 *
    069 * @see
    070 * <a href="https://www.ietf.org/rfc/rfc2396.txt">
    071 *  Uniform Resource Identifiers (URI): Generic Syntax
    072 * </a>
    073 *
    074 * @since 1.1
    075 * @deprecated Use the new UrlValidator in the routines package. This class
    076 * will be removed in a future release.
    077 */
    078@Deprecated
    079public class UrlValidator implements Serializable {
    080
    081    private static final int TOP_LEVEL_MAX_LEN = 4;
    082
    083    private static final int TOP_LEVEL_MIN_LEN = 2;
    084
    085    private static final long serialVersionUID = 24137157400029593L;
    086
    087    /**
    088     * Allows all validly formatted schemes to pass validation instead of
    089     * supplying a set of valid schemes.
    090     */
    091    public static final int ALLOW_ALL_SCHEMES = 1 << 0;
    092
    093    /**
    094     * Allow two slashes in the path component of the URL.
    095     */
    096    public static final int ALLOW_2_SLASHES = 1 << 1;
    097
    098    /**
    099     * Enabling this options disallows any URL fragments.
    100     */
    101    public static final int NO_FRAGMENTS = 1 << 2;
    102
    103    private static final String ALPHA_CHARS = "a-zA-Z";
    104
    105// NOT USED   private static final String ALPHA_NUMERIC_CHARS = ALPHA_CHARS + "\\d";
    106
    107    private static final String SPECIAL_CHARS = ";/@&=,.?:+$";
    108
    109    private static final String VALID_CHARS = "[^\\s" + SPECIAL_CHARS + "]";
    110
    111    // Drop numeric, and  "+-." for now
    112    private static final String AUTHORITY_CHARS_REGEX = "\\p{Alnum}\\-\\.";
    113
    114    private static final String ATOM = VALID_CHARS + '+';
    115
    116    /**
    117     * This expression derived/taken from the BNF for URI (RFC2396).
    118     */
    119    private static final String URL_REGEX =
    120            "^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\\?([^#]*))?(#(.*))?";
    121    //                                                                      12            3  4          5       6   7        8 9
    122    private static final Pattern URL_PATTERN = Pattern.compile(URL_REGEX);
    123
    124    /**
    125     * Schema/Protocol (ie. http:, ftp:, file:, etc).
    126     */
    127    private static final int PARSE_URL_SCHEME = 2;
    128
    129    /**
    130     * Includes hostname/ip and port number.
    131     */
    132    private static final int PARSE_URL_AUTHORITY = 4;
    133
    134    private static final int PARSE_URL_PATH = 5;
    135
    136    private static final int PARSE_URL_QUERY = 7;
    137
    138    private static final int PARSE_URL_FRAGMENT = 9;
    139
    140    /**
    141     * Protocol (for example, http:, ftp:, https:).
    142     */
    143    private static final Pattern SCHEME_PATTERN = Pattern.compile("^\\p{Alpha}[\\p{Alnum}\\+\\-\\.]*");
    144
    145    private static final String AUTHORITY_REGEX =
    146       "^([" + AUTHORITY_CHARS_REGEX + "]*)(:\\d*)?(.*)?";
    147    //                                                                            1                          2  3       4
    148    private static final Pattern AUTHORITY_PATTERN = Pattern.compile(AUTHORITY_REGEX);
    149
    150    private static final int PARSE_AUTHORITY_HOST_IP = 1;
    151
    152    private static final int PARSE_AUTHORITY_PORT = 2;
    153
    154    /**
    155     * Should always be empty.
    156     */
    157    private static final int PARSE_AUTHORITY_EXTRA = 3;
    158
    159    private static final Pattern PATH_PATTERN = Pattern.compile("^(/[-\\w:@&?=+,.!/~*'%$_;]*)?$");
    160
    161    private static final Pattern QUERY_PATTERN = Pattern.compile("^(.*)$");
    162
    163    private static final Pattern LEGAL_ASCII_PATTERN = Pattern.compile("^\\p{ASCII}+$");
    164
    165    private static final Pattern DOMAIN_PATTERN =
    166            Pattern.compile("^" + ATOM + "(\\." + ATOM + ")*$");
    167
    168    private static final Pattern PORT_PATTERN = Pattern.compile("^:(\\d{1,5})$");
    169
    170    private static final Pattern ATOM_PATTERN = Pattern.compile("^(" + ATOM + ").*?$");
    171
    172    private static final Pattern ALPHA_PATTERN = Pattern.compile("^[" + ALPHA_CHARS + "]");
    173
    174    /**
    175     * Holds the set of current validation options.
    176     */
    177    private final Flags options;
    178
    179    /**
    180     * The set of schemes that are allowed to be in a URL.
    181     */
    182    private final Set<String> allowedSchemes = new HashSet<>();
    183
    184    /**
    185     * If no schemes are provided, default to this set.
    186     */
    187    protected String[] defaultSchemes = {"http", "https", "ftp"};
    188
    189    /**
    190     * Create a UrlValidator with default properties.
    191     */
    192    public UrlValidator() {
    193        this(null);
    194    }
    195
    196    /**
    197     * Initialize a UrlValidator with the given validation options.
    198     *
    199     * @param options The options should be set using the public constants declared in
    200     * this class.  To set multiple options you simply add them together.  For example,
    201     * ALLOW_2_SLASHES + NO_FRAGMENTS enables both of those options.
    202     */
    203    public UrlValidator(final int options) {
    204        this(null, options);
    205    }
    206
    207    /**
    208     * Behavior of validation is modified by passing in several strings options:
    209     *
    210     * @param schemes Pass in one or more URL schemes to consider valid, passing in
    211     *        a null will default to "http,https,ftp" being valid.
    212     *        If a non-null schemes is specified then all valid schemes must
    213     *        be specified. Setting the ALLOW_ALL_SCHEMES option will
    214     *        ignore the contents of schemes.
    215     */
    216    public UrlValidator(final String[] schemes) {
    217        this(schemes, 0);
    218    }
    219
    220    /**
    221     * Behaviour of validation is modified by passing in options:
    222     *
    223     * @param schemes The set of valid schemes.
    224     * @param options The options should be set using the public constants declared in
    225     * this class.  To set multiple options you simply add them together.  For example,
    226     * ALLOW_2_SLASHES + NO_FRAGMENTS enables both of those options.
    227     */
    228    public UrlValidator(String[] schemes, final int options) {
    229        this.options = new Flags(options);
    230
    231        if (this.options.isOn(ALLOW_ALL_SCHEMES)) {
    232            return;
    233        }
    234
    235        if (schemes == null) {
    236            schemes = defaultSchemes;
    237        }
    238
    239        allowedSchemes.addAll(Arrays.asList(schemes));
    240    }
    241
    242    /**
    243     * Returns the number of times the token appears in the target.
    244     *
    245     * @param token Token value to be counted.
    246     * @param target Target value to count tokens in.
    247     * @return The number of tokens.
    248     */
    249    protected int countToken(final String token, final String target) {
    250        int tokenIndex = 0;
    251        int count = 0;
    252        while (tokenIndex != -1) {
    253            tokenIndex = target.indexOf(token, tokenIndex);
    254            if (tokenIndex > -1) {
    255                tokenIndex++;
    256                count++;
    257            }
    258        }
    259        return count;
    260    }
    261
    262    /**
    263     * Checks if a field has a valid URL address.
    264     *
    265     * @param value The value validation is being performed on.  A {@code null}
    266     * value is considered invalid.
    267     * @return true if the URL is valid.
    268     */
    269    public boolean isValid(final String value) {
    270        if (value == null || !LEGAL_ASCII_PATTERN.matcher(value).matches()) {
    271            return false;
    272        }
    273        // Check the whole url address structure
    274        final Matcher urlMatcher = URL_PATTERN.matcher(value);
    275        if (!urlMatcher.matches() || !isValidScheme(urlMatcher.group(PARSE_URL_SCHEME)) || !isValidAuthority(urlMatcher.group(PARSE_URL_AUTHORITY))
    276                || !isValidPath(urlMatcher.group(PARSE_URL_PATH))) {
    277            return false;
    278        }
    279        if (!isValidQuery(urlMatcher.group(PARSE_URL_QUERY)) || !isValidFragment(urlMatcher.group(PARSE_URL_FRAGMENT))) {
    280            return false;
    281        }
    282        return true;
    283    }
    284
    285    /**
    286     * Returns true if the authority is properly formatted.  An authority is the combination
    287     * of hostname and port.  A {@code null} authority value is considered invalid.
    288     *
    289     * @param authority Authority value to validate.
    290     * @return true if authority (hostname and port) is valid.
    291     */
    292    protected boolean isValidAuthority(final String authority) {
    293        if (authority == null) {
    294            return false;
    295        }
    296
    297        final InetAddressValidator inetAddressValidator =
    298                InetAddressValidator.getInstance();
    299
    300        final Matcher authorityMatcher = AUTHORITY_PATTERN.matcher(authority);
    301        if (!authorityMatcher.matches()) {
    302            return false;
    303        }
    304
    305        boolean hostname = false;
    306        // check if authority is IP address or hostname
    307        String hostIP = authorityMatcher.group(PARSE_AUTHORITY_HOST_IP);
    308        final boolean ipV4Address = inetAddressValidator.isValid(hostIP);
    309
    310        if (!ipV4Address) {
    311            // Domain is hostname name
    312            hostname = DOMAIN_PATTERN.matcher(hostIP).matches();
    313        }
    314
    315        //rightmost hostname will never start with a digit.
    316        if (hostname) {
    317            // LOW-TECH FIX FOR VALIDATOR-202
    318            // TODO: Rewrite to use ArrayList and .add semantics: see VALIDATOR-203
    319            final char[] chars = hostIP.toCharArray();
    320            int size = 1;
    321            for (final char element : chars) {
    322                if (element == '.') {
    323                    size++;
    324                }
    325            }
    326            final String[] domainSegment = new String[size];
    327            boolean match = true;
    328            int segmentCount = 0;
    329            int segmentLength = 0;
    330
    331            while (match) {
    332                final Matcher atomMatcher = ATOM_PATTERN.matcher(hostIP);
    333                match = atomMatcher.matches();
    334                if (match) {
    335                    domainSegment[segmentCount] = atomMatcher.group(1);
    336                    segmentLength = domainSegment[segmentCount].length() + 1;
    337                    hostIP =
    338                            segmentLength >= hostIP.length()
    339                            ? ""
    340                            : hostIP.substring(segmentLength);
    341
    342                    segmentCount++;
    343                }
    344            }
    345            final String topLevel = domainSegment[segmentCount - 1];
    346
    347
    348            // First letter of top level must be an alpha
    349            // Make sure there's a host name preceding the authority.
    350            if (topLevel.length() < TOP_LEVEL_MIN_LEN || topLevel.length() > TOP_LEVEL_MAX_LEN || !ALPHA_PATTERN.matcher(topLevel.substring(0, 1)).matches()
    351                    || segmentCount < 2) {
    352                return false;
    353            }
    354        }
    355
    356        if (!hostname && !ipV4Address) {
    357            return false;
    358        }
    359
    360        final String port = authorityMatcher.group(PARSE_AUTHORITY_PORT);
    361        if (port != null && !PORT_PATTERN.matcher(port).matches()) {
    362            return false;
    363        }
    364
    365        final String extra = authorityMatcher.group(PARSE_AUTHORITY_EXTRA);
    366        if (!GenericValidator.isBlankOrNull(extra)) {
    367            return false;
    368        }
    369
    370        return true;
    371    }
    372
    373    /**
    374     * Returns true if the given fragment is null or fragments are allowed.
    375     *
    376     * @param fragment Fragment value to validate.
    377     * @return true if fragment is valid.
    378     */
    379    protected boolean isValidFragment(final String fragment) {
    380        if (fragment == null) {
    381            return true;
    382        }
    383
    384        return options.isOff(NO_FRAGMENTS);
    385    }
    386
    387    /**
    388     * Returns true if the path is valid.  A {@code null} value is considered invalid.
    389     *
    390     * @param path Path value to validate.
    391     * @return true if path is valid.
    392     */
    393    protected boolean isValidPath(final String path) {
    394        if (path == null || !PATH_PATTERN.matcher(path).matches()) {
    395            return false;
    396        }
    397
    398        final int slash2Count = countToken("//", path);
    399        if (options.isOff(ALLOW_2_SLASHES) && slash2Count > 0) {
    400            return false;
    401        }
    402
    403        final int slashCount = countToken("/", path);
    404        final int dot2Count = countToken("..", path);
    405        if (dot2Count > 0 && slashCount - slash2Count - 1 <= dot2Count) {
    406            return false;
    407        }
    408
    409        return true;
    410    }
    411
    412    /**
    413     * Returns true if the query is null, or it's a properly formatted query string.
    414     *
    415     * @param query Query value to validate.
    416     * @return true if query is valid.
    417     */
    418    protected boolean isValidQuery(final String query) {
    419        if (query == null) {
    420            return true;
    421        }
    422
    423        return QUERY_PATTERN.matcher(query).matches();
    424    }
    425
    426    /**
    427     * Validate scheme. If schemes[] was initialized to a non-null,
    428     * then only those schemes are allowed.  Note this is slightly different
    429     * than for the constructor.
    430     *
    431     * @param scheme The scheme to validate.  A {@code null} value is considered
    432     * invalid.
    433     * @return true if valid.
    434     */
    435    protected boolean isValidScheme(final String scheme) {
    436        if (scheme == null || !SCHEME_PATTERN.matcher(scheme).matches() || options.isOff(ALLOW_ALL_SCHEMES) && !allowedSchemes.contains(scheme)) {
    437            return false;
    438        }
    439
    440        return true;
    441    }
    442}