Java tutorial
/* * ==================================================================== * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * */ package org.apache.http.impl.auth; import java.io.IOException; import java.nio.charset.Charset; import java.security.MessageDigest; import java.security.SecureRandom; import java.util.ArrayList; import java.util.Formatter; import java.util.HashSet; import java.util.List; import java.util.Locale; import java.util.Set; import java.util.StringTokenizer; import org.apache.http.Consts; import org.apache.http.Header; import org.apache.http.HttpEntity; import org.apache.http.HttpEntityEnclosingRequest; import org.apache.http.HttpRequest; import org.apache.http.annotation.NotThreadSafe; import org.apache.http.auth.AUTH; import org.apache.http.auth.AuthenticationException; import org.apache.http.auth.ChallengeState; import org.apache.http.auth.Credentials; import org.apache.http.auth.MalformedChallengeException; import org.apache.http.message.BasicHeaderValueFormatter; import org.apache.http.message.BasicNameValuePair; import org.apache.http.message.BufferedHeader; import org.apache.http.protocol.BasicHttpContext; import org.apache.http.protocol.HttpContext; import org.apache.http.util.Args; import org.apache.http.util.CharArrayBuffer; import org.apache.http.util.EncodingUtils; /** * Digest authentication scheme as defined in RFC 2617. * Both MD5 (default) and MD5-sess are supported. * Currently only qop=auth or no qop is supported. qop=auth-int * is unsupported. If auth and auth-int are provided, auth is * used. * <p/> * Since the digest username is included as clear text in the generated * Authentication header, the charset of the username must be compatible * with the HTTP element charset used by the connection. * * @since 4.0 */ @NotThreadSafe public class DigestScheme extends RFC2617Scheme { /** * Hexa values used when creating 32 character long digest in HTTP DigestScheme * in case of authentication. * * @see #encode(byte[]) */ private static final char[] HEXADECIMAL = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' }; /** Whether the digest authentication process is complete */ private boolean complete; private static final int QOP_UNKNOWN = -1; private static final int QOP_MISSING = 0; private static final int QOP_AUTH_INT = 1; private static final int QOP_AUTH = 2; private String lastNonce; private long nounceCount; private String cnonce; private String a1; private String a2; /** * @since 4.3 */ public DigestScheme(final Charset credentialsCharset) { super(credentialsCharset); this.complete = false; } /** * Creates an instance of <tt>DigestScheme</tt> with the given challenge * state. * * @since 4.2 * * @deprecated (4.3) do not use. */ @Deprecated public DigestScheme(final ChallengeState challengeState) { super(challengeState); } public DigestScheme() { this(Consts.ASCII); } /** * Processes the Digest challenge. * * @param header the challenge header * * @throws MalformedChallengeException is thrown if the authentication challenge * is malformed */ @Override public void processChallenge(final Header header) throws MalformedChallengeException { super.processChallenge(header); this.complete = true; } /** * Tests if the Digest authentication process has been completed. * * @return <tt>true</tt> if Digest authorization has been processed, * <tt>false</tt> otherwise. */ public boolean isComplete() { final String s = getParameter("stale"); if ("true".equalsIgnoreCase(s)) { return false; } else { return this.complete; } } /** * Returns textual designation of the digest authentication scheme. * * @return <code>digest</code> */ public String getSchemeName() { return "digest"; } /** * Returns <tt>false</tt>. Digest authentication scheme is request based. * * @return <tt>false</tt>. */ public boolean isConnectionBased() { return false; } public void overrideParamter(final String name, final String value) { getParameters().put(name, value); } /** * @deprecated (4.2) Use {@link org.apache.http.auth.ContextAwareAuthScheme#authenticate( * Credentials, HttpRequest, org.apache.http.protocol.HttpContext)} */ @Deprecated public Header authenticate(final Credentials credentials, final HttpRequest request) throws AuthenticationException { return authenticate(credentials, request, new BasicHttpContext()); } /** * Produces a digest authorization string for the given set of * {@link Credentials}, method name and URI. * * @param credentials A set of credentials to be used for athentication * @param request The request being authenticated * * @throws org.apache.http.auth.InvalidCredentialsException if authentication credentials * are not valid or not applicable for this authentication scheme * @throws AuthenticationException if authorization string cannot * be generated due to an authentication failure * * @return a digest authorization string */ @Override public Header authenticate(final Credentials credentials, final HttpRequest request, final HttpContext context) throws AuthenticationException { Args.notNull(credentials, "Credentials"); Args.notNull(request, "HTTP request"); if (getParameter("realm") == null) { throw new AuthenticationException("missing realm in challenge"); } if (getParameter("nonce") == null) { throw new AuthenticationException("missing nonce in challenge"); } // Add method name and request-URI to the parameter map getParameters().put("methodname", request.getRequestLine().getMethod()); getParameters().put("uri", request.getRequestLine().getUri()); final String charset = getParameter("charset"); if (charset == null) { getParameters().put("charset", getCredentialsCharset(request)); } return createDigestHeader(credentials, request); } private static MessageDigest createMessageDigest(final String digAlg) throws UnsupportedDigestAlgorithmException { try { return MessageDigest.getInstance(digAlg); } catch (final Exception e) { throw new UnsupportedDigestAlgorithmException( "Unsupported algorithm in HTTP Digest authentication: " + digAlg); } } /** * Creates digest-response header as defined in RFC2617. * * @param credentials User credentials * * @return The digest-response as String. */ private Header createDigestHeader(final Credentials credentials, final HttpRequest request) throws AuthenticationException { final String uri = getParameter("uri"); final String realm = getParameter("realm"); final String nonce = getParameter("nonce"); final String opaque = getParameter("opaque"); final String method = getParameter("methodname"); String algorithm = getParameter("algorithm"); // If an algorithm is not specified, default to MD5. if (algorithm == null) { algorithm = "MD5"; } final Set<String> qopset = new HashSet<String>(8); int qop = QOP_UNKNOWN; final String qoplist = getParameter("qop"); if (qoplist != null) { final StringTokenizer tok = new StringTokenizer(qoplist, ","); while (tok.hasMoreTokens()) { final String variant = tok.nextToken().trim(); qopset.add(variant.toLowerCase(Locale.US)); } if (request instanceof HttpEntityEnclosingRequest && qopset.contains("auth-int")) { qop = QOP_AUTH_INT; } else if (qopset.contains("auth")) { qop = QOP_AUTH; } } else { qop = QOP_MISSING; } if (qop == QOP_UNKNOWN) { throw new AuthenticationException("None of the qop methods is supported: " + qoplist); } String charset = getParameter("charset"); if (charset == null) { charset = "ISO-8859-1"; } String digAlg = algorithm; if (digAlg.equalsIgnoreCase("MD5-sess")) { digAlg = "MD5"; } final MessageDigest digester; try { digester = createMessageDigest(digAlg); } catch (final UnsupportedDigestAlgorithmException ex) { throw new AuthenticationException("Unsuppported digest algorithm: " + digAlg); } final String uname = credentials.getUserPrincipal().getName(); final String pwd = credentials.getPassword(); if (nonce.equals(this.lastNonce)) { nounceCount++; } else { nounceCount = 1; cnonce = null; lastNonce = nonce; } final StringBuilder sb = new StringBuilder(256); final Formatter formatter = new Formatter(sb, Locale.US); formatter.format("%08x", nounceCount); formatter.close(); final String nc = sb.toString(); if (cnonce == null) { cnonce = createCnonce(); } a1 = null; a2 = null; // 3.2.2.2: Calculating digest if (algorithm.equalsIgnoreCase("MD5-sess")) { // H( unq(username-value) ":" unq(realm-value) ":" passwd ) // ":" unq(nonce-value) // ":" unq(cnonce-value) // calculated one per session sb.setLength(0); sb.append(uname).append(':').append(realm).append(':').append(pwd); final String checksum = encode(digester.digest(EncodingUtils.getBytes(sb.toString(), charset))); sb.setLength(0); sb.append(checksum).append(':').append(nonce).append(':').append(cnonce); a1 = sb.toString(); } else { // unq(username-value) ":" unq(realm-value) ":" passwd sb.setLength(0); sb.append(uname).append(':').append(realm).append(':').append(pwd); a1 = sb.toString(); } final String hasha1 = encode(digester.digest(EncodingUtils.getBytes(a1, charset))); if (qop == QOP_AUTH) { // Method ":" digest-uri-value a2 = method + ':' + uri; } else if (qop == QOP_AUTH_INT) { // Method ":" digest-uri-value ":" H(entity-body) HttpEntity entity = null; if (request instanceof HttpEntityEnclosingRequest) { entity = ((HttpEntityEnclosingRequest) request).getEntity(); } if (entity != null && !entity.isRepeatable()) { // If the entity is not repeatable, try falling back onto QOP_AUTH if (qopset.contains("auth")) { qop = QOP_AUTH; a2 = method + ':' + uri; } else { throw new AuthenticationException( "Qop auth-int cannot be used with " + "a non-repeatable entity"); } } else { final HttpEntityDigester entityDigester = new HttpEntityDigester(digester); try { if (entity != null) { entity.writeTo(entityDigester); } entityDigester.close(); } catch (final IOException ex) { throw new AuthenticationException("I/O error reading entity content", ex); } a2 = method + ':' + uri + ':' + encode(entityDigester.getDigest()); } } else { a2 = method + ':' + uri; } final String hasha2 = encode(digester.digest(EncodingUtils.getBytes(a2, charset))); // 3.2.2.1 final String digestValue; if (qop == QOP_MISSING) { sb.setLength(0); sb.append(hasha1).append(':').append(nonce).append(':').append(hasha2); digestValue = sb.toString(); } else { sb.setLength(0); sb.append(hasha1).append(':').append(nonce).append(':').append(nc).append(':').append(cnonce) .append(':').append(qop == QOP_AUTH_INT ? "auth-int" : "auth").append(':').append(hasha2); digestValue = sb.toString(); } final String digest = encode(digester.digest(EncodingUtils.getAsciiBytes(digestValue))); final CharArrayBuffer buffer = new CharArrayBuffer(128); if (isProxy()) { buffer.append(AUTH.PROXY_AUTH_RESP); } else { buffer.append(AUTH.WWW_AUTH_RESP); } buffer.append(": Digest "); final List<BasicNameValuePair> params = new ArrayList<BasicNameValuePair>(20); params.add(new BasicNameValuePair("username", uname)); params.add(new BasicNameValuePair("realm", realm)); params.add(new BasicNameValuePair("nonce", nonce)); params.add(new BasicNameValuePair("uri", uri)); params.add(new BasicNameValuePair("response", digest)); if (qop != QOP_MISSING) { params.add(new BasicNameValuePair("qop", qop == QOP_AUTH_INT ? "auth-int" : "auth")); params.add(new BasicNameValuePair("nc", nc)); params.add(new BasicNameValuePair("cnonce", cnonce)); } // algorithm cannot be null here params.add(new BasicNameValuePair("algorithm", algorithm)); if (opaque != null) { params.add(new BasicNameValuePair("opaque", opaque)); } for (int i = 0; i < params.size(); i++) { final BasicNameValuePair param = params.get(i); if (i > 0) { buffer.append(", "); } final String name = param.getName(); final boolean noQuotes = ("nc".equals(name) || "qop".equals(name) || "algorithm".equals(name)); BasicHeaderValueFormatter.INSTANCE.formatNameValuePair(buffer, param, !noQuotes); } return new BufferedHeader(buffer); } String getCnonce() { return cnonce; } String getA1() { return a1; } String getA2() { return a2; } /** * Encodes the 128 bit (16 bytes) MD5 digest into a 32 characters long * <CODE>String</CODE> according to RFC 2617. * * @param binaryData array containing the digest * @return encoded MD5, or <CODE>null</CODE> if encoding failed */ static String encode(final byte[] binaryData) { final int n = binaryData.length; final char[] buffer = new char[n * 2]; for (int i = 0; i < n; i++) { final int low = (binaryData[i] & 0x0f); final int high = ((binaryData[i] & 0xf0) >> 4); buffer[i * 2] = HEXADECIMAL[high]; buffer[(i * 2) + 1] = HEXADECIMAL[low]; } return new String(buffer); } /** * Creates a random cnonce value based on the current time. * * @return The cnonce value as String. */ public static String createCnonce() { final SecureRandom rnd = new SecureRandom(); final byte[] tmp = new byte[8]; rnd.nextBytes(tmp); return encode(tmp); } @Override public String toString() { final StringBuilder builder = new StringBuilder(); builder.append("DIGEST [complete=").append(complete).append(", nonce=").append(lastNonce).append(", nc=") .append(nounceCount).append("]"); return builder.toString(); } }