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    1   /*
    2    * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/auth/DigestScheme.java,v 1.22 2004/12/30 11:01:27 oglueck Exp $
    3    * $Revision: 480424 $
    4    * $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $
    5    *
    6    * ====================================================================
    7    *
    8    *  Licensed to the Apache Software Foundation (ASF) under one or more
    9    *  contributor license agreements.  See the NOTICE file distributed with
    10   *  this work for additional information regarding copyright ownership.
    11   *  The ASF licenses this file to You under the Apache License, Version 2.0
    12   *  (the "License"); you may not use this file except in compliance with
    13   *  the License.  You may obtain a copy of the License at
    14   *
    15   *      http://www.apache.org/licenses/LICENSE-2.0
    16   *
    17   *  Unless required by applicable law or agreed to in writing, software
    18   *  distributed under the License is distributed on an "AS IS" BASIS,
    19   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    20   *  See the License for the specific language governing permissions and
    21   *  limitations under the License.
    22   * ====================================================================
    23   *
    24   * This software consists of voluntary contributions made by many
    25   * individuals on behalf of the Apache Software Foundation.  For more
    26   * information on the Apache Software Foundation, please see
    27   * <http://www.apache.org/>.
    28   *
    29   */
    30
    31  package org.apache.commons.httpclient.auth;
    32
    33  import java.security.MessageDigest;
    34  import java.security.NoSuchAlgorithmException;
    35  import java.util.ArrayList;
    36  import java.util.List;
    37  import java.util.StringTokenizer;
    38
    39  import org.apache.commons.httpclient.Credentials;
    40  import org.apache.commons.httpclient.HttpClientError;
    41  import org.apache.commons.httpclient.HttpMethod;
    42  import org.apache.commons.httpclient.NameValuePair;
    43  import org.apache.commons.httpclient.UsernamePasswordCredentials;
    44  import org.apache.commons.httpclient.util.EncodingUtil;
    45  import org.apache.commons.httpclient.util.ParameterFormatter;
    46  import org.apache.commons.logging.Log;
    47  import org.apache.commons.logging.LogFactory;
    48
    49  /**
    50   * <p>
    51   * Digest authentication scheme as defined in RFC 2617.
    52   * Both MD5 (default) and MD5-sess are supported.
    53   * Currently only qop=auth or no qop is supported. qop=auth-int
    54   * is unsupported. If auth and auth-int are provided, auth is
    55   * used.
    56   * </p>
    57   * <p>
    58   * Credential charset is configured via the
    59   * {@link org.apache.commons.httpclient.params.HttpMethodParams#CREDENTIAL_CHARSET credential
    60   * charset} parameter.  Since the digest username is included as clear text in the generated
    61   * Authentication header, the charset of the username must be compatible with the
    62   * {@link org.apache.commons.httpclient.params.HttpMethodParams#HTTP_ELEMENT_CHARSET http element
    63   * charset}.
    64   * </p>
    65   * TODO: make class more stateful regarding repeated authentication requests
    66   *
    67   * @author <a href="mailto:remm@apache.org">Remy Maucherat</a>
    68   * @author Rodney Waldhoff
    69   * @author <a href="mailto:jsdever@apache.org">Jeff Dever</a>
    70   * @author Ortwin Gl?ck
    71   * @author Sean C. Sullivan
    72   * @author <a href="mailto:adrian@ephox.com">Adrian Sutton</a>
    73   * @author <a href="mailto:mbowler@GargoyleSoftware.com">Mike Bowler</a>
    74   * @author <a href="mailto:oleg@ural.ru">Oleg Kalnichevski</a>
    75   */
    76
    77  public class DigestScheme extends RFC2617Scheme {
    78
    79      /** Log object for this class. */
    80      private static final Log LOG = LogFactory.getLog(DigestScheme.class);
    81
    82      /**
    83       * Hexa values used when creating 32 character long digest in HTTP DigestScheme
    84       * in case of authentication.
    85       *
    86       * @see #encode(byte[])
    87       */
    88      private static final char[] HEXADECIMAL = {
    89          '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd',
    90          'e', 'f'
    91      };
    92
    93      /** Whether the digest authentication process is complete */
    94      private boolean complete;
    95
    96      //TODO: supply a real nonce-count, currently a server will interprete a repeated request as a replay
    97      private static final String NC = "00000001"; //nonce-count is always 1
    98      private static final int QOP_MISSING = 0;
    99      private static final int QOP_AUTH_INT = 1;
    100     private static final int QOP_AUTH = 2;
    101
    102     private int qopVariant = QOP_MISSING;
    103     private String cnonce;
    104
    105     private final ParameterFormatter formatter;
    106     /**
    107      * Default constructor for the digest authetication scheme.
    108      *
    109      * @since 3.0
    110      */
    111     public DigestScheme() {
    112         super();
    113         this.complete = false;
    114         this.formatter = new ParameterFormatter();
    115     }
    116
    117     /**
    118      * Gets an ID based upon the realm and the nonce value.  This ensures that requests
    119      * to the same realm with different nonce values will succeed.  This differentiation
    120      * allows servers to request re-authentication using a fresh nonce value.
    121      *
    122      * @deprecated no longer used
    123      */
    124     public String getID() {
    125
    126         String id = getRealm();
    127         String nonce = getParameter("nonce");
    128         if (nonce != null) {
    129             id += "-" + nonce;
    130         }
    131
    132         return id;
    133     }
    134
    135     /**
    136      * Constructor for the digest authetication scheme.
    137      *
    138      * @param challenge authentication challenge
    139      *
    140      * @throws MalformedChallengeException is thrown if the authentication challenge
    141      * is malformed
    142      *
    143      * @deprecated Use parameterless constructor and {@link AuthScheme#processChallenge(String)}
    144      *             method
    145      */
    146     public DigestScheme(final String challenge)
    147       throws MalformedChallengeException {
    148         this();
    149         processChallenge(challenge);
    150     }
    151
    152     /**
    153      * Processes the Digest challenge.
    154      *
    155      * @param challenge the challenge string
    156      *
    157      * @throws MalformedChallengeException is thrown if the authentication challenge
    158      * is malformed
    159      *
    160      * @since 3.0
    161      */
    162     public void processChallenge(final String challenge)
    163       throws MalformedChallengeException {
    164         super.processChallenge(challenge);
    165
    166         if (getParameter("realm") == null) {
    167             throw new MalformedChallengeException("missing realm in challange");
    168         }
    169         if (getParameter("nonce") == null) {
    170             throw new MalformedChallengeException("missing nonce in challange");
    171         }
    172
    173         boolean unsupportedQop = false;
    174         // qop parsing
    175         String qop = getParameter("qop");
    176         if (qop != null) {
    177             StringTokenizer tok = new StringTokenizer(qop,",");
    178             while (tok.hasMoreTokens()) {
    179                 String variant = tok.nextToken().trim();
    180                 if (variant.equals("auth")) {
    181                     qopVariant = QOP_AUTH;
    182                     break; //that's our favourite, because auth-int is unsupported
    183                 } else if (variant.equals("auth-int")) {
    184                     qopVariant = QOP_AUTH_INT;
    185                 } else {
    186                     unsupportedQop = true;
    187                     LOG.warn("Unsupported qop detected: "+ variant);
    188                 }
    189             }
    190         }
    191
    192         if (unsupportedQop && (qopVariant == QOP_MISSING)) {
    193             throw new MalformedChallengeException("None of the qop methods is supported");
    194         }
    195
    196         cnonce = createCnonce();
    197         this.complete = true;
    198     }
    199
    200     /**
    201      * Tests if the Digest authentication process has been completed.
    202      *
    203      * @return <tt>true</tt> if Digest authorization has been processed,
    204      *   <tt>false</tt> otherwise.
    205      *
    206      * @since 3.0
    207      */
    208     public boolean isComplete() {
    209         String s = getParameter("stale");
    210         if ("true".equalsIgnoreCase(s)) {
    211             return false;
    212         } else {
    213             return this.complete;
    214         }
    215     }
    216
    217     /**
    218      * Returns textual designation of the digest authentication scheme.
    219      *
    220      * @return <code>digest</code>
    221      */
    222     public String getSchemeName() {
    223         return "digest";
    224     }
    225
    226     /**
    227      * Returns <tt>false</tt>. Digest authentication scheme is request based.
    228      *
    229      * @return <tt>false</tt>.
    230      *
    231      * @since 3.0
    232      */
    233     public boolean isConnectionBased() {
    234         return false;
    235     }
    236
    237     /**
    238      * Produces a digest authorization string for the given set of
    239      * {@link Credentials}, method name and URI.
    240      *
    241      * @param credentials A set of credentials to be used for athentication
    242      * @param method the name of the method that requires authorization.
    243      * @param uri The URI for which authorization is needed.
    244      *
    245      * @throws InvalidCredentialsException if authentication credentials
    246      *         are not valid or not applicable for this authentication scheme
    247      * @throws AuthenticationException if authorization string cannot
    248      *   be generated due to an authentication failure
    249      *
    250      * @return a digest authorization string
    251      *
    252      * @see org.apache.commons.httpclient.HttpMethod#getName()
    253      * @see org.apache.commons.httpclient.HttpMethod#getPath()
    254      *
    255      * @deprecated Use {@link #authenticate(Credentials, HttpMethod)}
    256      */
    257     public String authenticate(Credentials credentials, String method, String uri)
    258       throws AuthenticationException {
    259
    260         LOG.trace("enter DigestScheme.authenticate(Credentials, String, String)");
    261
    262         UsernamePasswordCredentials usernamepassword = null;
    263         try {
    264             usernamepassword = (UsernamePasswordCredentials) credentials;
    265         } catch (ClassCastException e) {
    266             throw new InvalidCredentialsException(
    267              "Credentials cannot be used for digest authentication: "
    268               + credentials.getClass().getName());
    269         }
    270         getParameters().put("methodname", method);
    271         getParameters().put("uri", uri);
    272         String digest = createDigest(
    273             usernamepassword.getUserName(),
    274             usernamepassword.getPassword());
    275         return "Digest " + createDigestHeader(usernamepassword.getUserName(), digest);
    276     }
    277
    278     /**
    279      * Produces a digest authorization string for the given set of
    280      * {@link Credentials}, method name and URI.
    281      *
    282      * @param credentials A set of credentials to be used for athentication
    283      * @param method The method being authenticated
    284      *
    285      * @throws InvalidCredentialsException if authentication credentials
    286      *         are not valid or not applicable for this authentication scheme
    287      * @throws AuthenticationException if authorization string cannot
    288      *   be generated due to an authentication failure
    289      *
    290      * @return a digest authorization string
    291      *
    292      * @since 3.0
    293      */
    294     public String authenticate(Credentials credentials, HttpMethod method)
    295     throws AuthenticationException {
    296
    297         LOG.trace("enter DigestScheme.authenticate(Credentials, HttpMethod)");
    298
    299         UsernamePasswordCredentials usernamepassword = null;
    300         try {
    301             usernamepassword = (UsernamePasswordCredentials) credentials;
    302         } catch (ClassCastException e) {
    303             throw new InvalidCredentialsException(
    304                     "Credentials cannot be used for digest authentication: "
    305                     + credentials.getClass().getName());
    306         }
    307         getParameters().put("methodname", method.getName());
    308         StringBuffer buffer = new StringBuffer(method.getPath());
    309         String query = method.getQueryString();
    310         if (query != null) {
    311             if (query.indexOf("?") != 0) {
    312                 buffer.append("?");
    313             }
    314             buffer.append(method.getQueryString());
    315         }
    316         getParameters().put("uri", buffer.toString());
    317         String charset = getParameter("charset");
    318         if (charset == null) {
    319             getParameters().put("charset", method.getParams().getCredentialCharset());
    320         }
    321         String digest = createDigest(
    322             usernamepassword.getUserName(),
    323             usernamepassword.getPassword());
    324         return "Digest " + createDigestHeader(usernamepassword.getUserName(),
    325                 digest);
    326     }
    327
    328     /**
    329      * Creates an MD5 response digest.
    330      *
    331      * @param uname Username
    332      * @param pwd Password
    333      * @param charset The credential charset
    334      *
    335      * @return The created digest as string. This will be the response tag's
    336      *         value in the Authentication HTTP header.
    337      * @throws AuthenticationException when MD5 is an unsupported algorithm
    338      */
    339     private String createDigest(final String uname, final String pwd) throws AuthenticationException {
    340
    341         LOG.trace("enter DigestScheme.createDigest(String, String, Map)");
    342
    343         final String digAlg = "MD5";
    344
    345         // Collecting required tokens
    346         String uri = getParameter("uri");
    347         String realm = getParameter("realm");
    348         String nonce = getParameter("nonce");
    349         String qop = getParameter("qop");
    350         String method = getParameter("methodname");
    351         String algorithm = getParameter("algorithm");
    352         // If an algorithm is not specified, default to MD5.
    353         if (algorithm == null) {
    354             algorithm = "MD5";
    355         }
    356         // If an charset is not specified, default to ISO-8859-1.
    357         String charset = getParameter("charset");
    358         if (charset == null) {
    359             charset = "ISO-8859-1";
    360         }
    361
    362         if (qopVariant == QOP_AUTH_INT) {
    363             LOG.warn("qop=auth-int is not supported");
    364             throw new AuthenticationException(
    365                 "Unsupported qop in HTTP Digest authentication");
    366         }
    367
    368         MessageDigest md5Helper;
    369
    370         try {
    371             md5Helper = MessageDigest.getInstance(digAlg);
    372         } catch (Exception e) {
    373             throw new AuthenticationException(
    374               "Unsupported algorithm in HTTP Digest authentication: "
    375                + digAlg);
    376         }
    377
    378         // 3.2.2.2: Calculating digest
    379         StringBuffer tmp = new StringBuffer(uname.length() + realm.length() + pwd.length() + 2);
    380         tmp.append(uname);
    381         tmp.append(':');
    382         tmp.append(realm);
    383         tmp.append(':');
    384         tmp.append(pwd);
    385         // unq(username-value) ":" unq(realm-value) ":" passwd
    386         String a1 = tmp.toString();
    387         //a1 is suitable for MD5 algorithm
    388         if(algorithm.equals("MD5-sess")) {
    389             // H( unq(username-value) ":" unq(realm-value) ":" passwd )
    390             //      ":" unq(nonce-value)
    391             //      ":" unq(cnonce-value)
    392
    393             String tmp2=encode(md5Helper.digest(EncodingUtil.getBytes(a1, charset)));
    394             StringBuffer tmp3 = new StringBuffer(tmp2.length() + nonce.length() + cnonce.length() + 2);
    395             tmp3.append(tmp2);
    396             tmp3.append(':');
    397             tmp3.append(nonce);
    398             tmp3.append(':');
    399             tmp3.append(cnonce);
    400             a1 = tmp3.toString();
    401         } else if(!algorithm.equals("MD5")) {
    402             LOG.warn("Unhandled algorithm " + algorithm + " requested");
    403         }
    404         String md5a1 = encode(md5Helper.digest(EncodingUtil.getBytes(a1, charset)));
    405
    406         String a2 = null;
    407         if (qopVariant == QOP_AUTH_INT) {
    408             LOG.error("Unhandled qop auth-int");
    409             //we do not have access to the entity-body or its hash
    410             //TODO: add Method ":" digest-uri-value ":" H(entity-body)
    411         } else {
    412             a2 = method + ":" + uri;
    413         }
    414         String md5a2 = encode(md5Helper.digest(EncodingUtil.getAsciiBytes(a2)));
    415
    416         // 3.2.2.1
    417         String serverDigestValue;
    418         if (qopVariant == QOP_MISSING) {
    419             LOG.debug("Using null qop method");
    420             StringBuffer tmp2 = new StringBuffer(md5a1.length() + nonce.length() + md5a2.length());
    421             tmp2.append(md5a1);
    422             tmp2.append(':');
    423             tmp2.append(nonce);
    424             tmp2.append(':');
    425             tmp2.append(md5a2);
    426             serverDigestValue = tmp2.toString();
    427         } else {
    428             if (LOG.isDebugEnabled()) {
    429                 LOG.debug("Using qop method " + qop);
    430             }
    431             String qopOption = getQopVariantString();
    432             StringBuffer tmp2 = new StringBuffer(md5a1.length() + nonce.length()
    433                 + NC.length() + cnonce.length() + qopOption.length() + md5a2.length() + 5);
    434             tmp2.append(md5a1);
    435             tmp2.append(':');
    436             tmp2.append(nonce);
    437             tmp2.append(':');
    438             tmp2.append(NC);
    439             tmp2.append(':');
    440             tmp2.append(cnonce);
    441             tmp2.append(':');
    442             tmp2.append(qopOption);
    443             tmp2.append(':');
    444             tmp2.append(md5a2);
    445             serverDigestValue = tmp2.toString();
    446         }
    447
    448         String serverDigest =
    449             encode(md5Helper.digest(EncodingUtil.getAsciiBytes(serverDigestValue)));
    450
    451         return serverDigest;
    452     }
    453
    454     /**
    455      * Creates digest-response header as defined in RFC2617.
    456      *
    457      * @param uname Username
    458      * @param digest The response tag's value as String.
    459      *
    460      * @return The digest-response as String.
    461      */
    462     private String createDigestHeader(final String uname, final String digest)
    463         throws AuthenticationException {
    464
    465         LOG.trace("enter DigestScheme.createDigestHeader(String, Map, "
    466             + "String)");
    467
    468         String uri = getParameter("uri");
    469         String realm = getParameter("realm");
    470         String nonce = getParameter("nonce");
    471         String opaque = getParameter("opaque");
    472         String response = digest;
    473         String algorithm = getParameter("algorithm");
    474
    475         List params = new ArrayList(20);
    476         params.add(new NameValuePair("username", uname));
    477         params.add(new NameValuePair("realm", realm));
    478         params.add(new NameValuePair("nonce", nonce));
    479         params.add(new NameValuePair("uri", uri));
    480         params.add(new NameValuePair("response", response));
    481
    482         if (qopVariant != QOP_MISSING) {
    483             params.add(new NameValuePair("qop", getQopVariantString()));
    484             params.add(new NameValuePair("nc", NC));
    485             params.add(new NameValuePair("cnonce", this.cnonce));
    486         }
    487         if (algorithm != null) {
    488             params.add(new NameValuePair("algorithm", algorithm));
    489         }
    490         if (opaque != null) {
    491             params.add(new NameValuePair("opaque", opaque));
    492         }
    493
    494         StringBuffer buffer = new StringBuffer();
    495         for (int i = 0; i < params.size(); i++) {
    496             NameValuePair param = (NameValuePair) params.get(i);
    497             if (i > 0) {
    498                 buffer.append(", ");
    499             }
    500             boolean noQuotes = "nc".equals(param.getName()) ||
    501                                "qop".equals(param.getName());
    502             this.formatter.setAlwaysUseQuotes(!noQuotes);
    503             this.formatter.format(buffer, param);
    504         }
    505         return buffer.toString();
    506     }
    507
    508     private String getQopVariantString() {
    509         String qopOption;
    510         if (qopVariant == QOP_AUTH_INT) {
    511             qopOption = "auth-int";
    512         } else {
    513             qopOption = "auth";
    514         }
    515         return qopOption;
    516     }
    517
    518     /**
    519      * Encodes the 128 bit (16 bytes) MD5 digest into a 32 characters long
    520      * <CODE>String</CODE> according to RFC 2617.
    521      *
    522      * @param binaryData array containing the digest
    523      * @return encoded MD5, or <CODE>null</CODE> if encoding failed
    524      */
    525     private static String encode(byte[] binaryData) {
    526         LOG.trace("enter DigestScheme.encode(byte[])");
    527
    528         if (binaryData.length != 16) {
    529             return null;
    530         }
    531
    532         char[] buffer = new char[32];
    533         for (int i = 0; i < 16; i++) {
    534             int low = (int) (binaryData[i] & 0x0f);
    535             int high = (int) ((binaryData[i] & 0xf0) >> 4);
    536             buffer[i * 2] = HEXADECIMAL[high];
    537             buffer[(i * 2) + 1] = HEXADECIMAL[low];
    538         }
    539
    540         return new String(buffer);
    541     }
    542
    543
    544     /**
    545      * Creates a random cnonce value based on the current time.
    546      *
    547      * @return The cnonce value as String.
    548      * @throws HttpClientError if MD5 algorithm is not supported.
    549      */
    550     public static String createCnonce() {
    551         LOG.trace("enter DigestScheme.createCnonce()");
    552
    553         String cnonce;
    554         final String digAlg = "MD5";
    555         MessageDigest md5Helper;
    556
    557         try {
    558             md5Helper = MessageDigest.getInstance(digAlg);
    559         } catch (NoSuchAlgorithmException e) {
    560             throw new HttpClientError(
    561               "Unsupported algorithm in HTTP Digest authentication: "
    562                + digAlg);
    563         }
    564
    565         cnonce = Long.toString(System.currentTimeMillis());
    566         cnonce = encode(md5Helper.digest(EncodingUtil.getAsciiBytes(cnonce)));
    567
    568         return cnonce;
    569     }
    570 }