1 /* 2 * Copyright (c) 2000, 2004, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package javax.security.sasl; 27 28 /** 29 * Performs SASL authentication as a server. 30 *<p> 31 * A server such an LDAP server gets an instance of this 32 * class in order to perform authentication defined by a specific SASL 33 * mechanism. Invoking methods on the <tt>SaslServer</tt> instance 34 * generates challenges according to the SASL 35 * mechanism implemented by the <tt>SaslServer</tt>. 36 * As the authentication proceeds, the instance 37 * encapsulates the state of a SASL server's authentication exchange. 38 *<p> 39 * Here's an example of how an LDAP server might use a <tt>SaslServer</tt>. 40 * It first gets an instance of a <tt>SaslServer</tt> for the SASL mechanism 41 * requested by the client: 42 *<blockquote><pre> 43 * SaslServer ss = Sasl.createSaslServer(mechanism, 44 * "ldap", myFQDN, props, callbackHandler); 45 *</pre></blockquote> 46 * It can then proceed to use the server for authentication. 47 * For example, suppose the LDAP server received an LDAP BIND request 48 * containing the name of the SASL mechanism and an (optional) initial 49 * response. It then might use the server as follows: 50 *<blockquote><pre>{@code 51 * while (!ss.isComplete()) { 52 * try { 53 * byte[] challenge = ss.evaluateResponse(response); 54 * if (ss.isComplete()) { 55 * status = ldap.sendBindResponse(mechanism, challenge, SUCCESS); 56 * } else { 57 * status = ldap.sendBindResponse(mechanism, challenge, 58 SASL_BIND_IN_PROGRESS); 59 * response = ldap.readBindRequest(); 60 * } 61 * } catch (SaslException e) { 62 * status = ldap.sendErrorResponse(e); 63 * break; 64 * } 65 * } 66 * if (ss.isComplete() && status == SUCCESS) { 67 * String qop = (String) sc.getNegotiatedProperty(Sasl.QOP); 68 * if (qop != null 69 * && (qop.equalsIgnoreCase("auth-int") 70 * || qop.equalsIgnoreCase("auth-conf"))) { 71 * 72 * // Use SaslServer.wrap() and SaslServer.unwrap() for future 73 * // communication with client 74 * ldap.in = new SecureInputStream(ss, ldap.in); 75 * ldap.out = new SecureOutputStream(ss, ldap.out); 76 * } 77 * } 78 *}</pre></blockquote> 79 * 80 * @since 1.5 81 * 82 * @see Sasl 83 * @see SaslServerFactory 84 * 85 * @author Rosanna Lee 86 * @author Rob Weltman 87 */ 88 public abstract interface SaslServer { 89 90 /** 91 * Returns the IANA-registered mechanism name of this SASL server. 92 * (e.g. "CRAM-MD5", "GSSAPI"). 93 * @return A non-null string representing the IANA-registered mechanism name. 94 */ 95 public abstract String getMechanismName(); 96 97 /** 98 * Evaluates the response data and generates a challenge. 99 * 100 * If a response is received from the client during the authentication 101 * process, this method is called to prepare an appropriate next 102 * challenge to submit to the client. The challenge is null if the 103 * authentication has succeeded and no more challenge data is to be sent 104 * to the client. It is non-null if the authentication must be continued 105 * by sending a challenge to the client, or if the authentication has 106 * succeeded but challenge data needs to be processed by the client. 107 * <tt>isComplete()</tt> should be called 108 * after each call to <tt>evaluateResponse()</tt>,to determine if any further 109 * response is needed from the client. 110 * 111 * @param response The non-null (but possibly empty) response sent 112 * by the client. 113 * 114 * @return The possibly null challenge to send to the client. 115 * It is null if the authentication has succeeded and there is 116 * no more challenge data to be sent to the client. 117 * @exception SaslException If an error occurred while processing 118 * the response or generating a challenge. 119 */ 120 public abstract byte[] evaluateResponse(byte[] response) 121 throws SaslException; 122 123 /** 124 * Determines whether the authentication exchange has completed. 125 * This method is typically called after each invocation of 126 * <tt>evaluateResponse()</tt> to determine whether the 127 * authentication has completed successfully or should be continued. 128 * @return true if the authentication exchange has completed; false otherwise. 129 */ 130 public abstract boolean isComplete(); 131 132 /** 133 * Reports the authorization ID in effect for the client of this 134 * session. 135 * This method can only be called if isComplete() returns true. 136 * @return The authorization ID of the client. 137 * @exception IllegalStateException if this authentication session has not completed 138 */ 139 public String getAuthorizationID(); 140 141 /** 142 * Unwraps a byte array received from the client. 143 * This method can be called only after the authentication exchange has 144 * completed (i.e., when <tt>isComplete()</tt> returns true) and only if 145 * the authentication exchange has negotiated integrity and/or privacy 146 * as the quality of protection; otherwise, 147 * an <tt>IllegalStateException</tt> is thrown. 148 *<p> 149 * <tt>incoming</tt> is the contents of the SASL buffer as defined in RFC 2222 150 * without the leading four octet field that represents the length. 151 * <tt>offset</tt> and <tt>len</tt> specify the portion of <tt>incoming</tt> 152 * to use. 153 * 154 * @param incoming A non-null byte array containing the encoded bytes 155 * from the client. 156 * @param offset The starting position at <tt>incoming</tt> of the bytes to use. 157 * @param len The number of bytes from <tt>incoming</tt> to use. 158 * @return A non-null byte array containing the decoded bytes. 159 * @exception SaslException if <tt>incoming</tt> cannot be successfully 160 * unwrapped. 161 * @exception IllegalStateException if the authentication exchange has 162 * not completed, or if the negotiated quality of protection 163 * has neither integrity nor privacy 164 */ 165 public abstract byte[] unwrap(byte[] incoming, int offset, int len) 166 throws SaslException; 167 168 /** 169 * Wraps a byte array to be sent to the client. 170 * This method can be called only after the authentication exchange has 171 * completed (i.e., when <tt>isComplete()</tt> returns true) and only if 172 * the authentication exchange has negotiated integrity and/or privacy 173 * as the quality of protection; otherwise, a <tt>SaslException</tt> is thrown. 174 *<p> 175 * The result of this method 176 * will make up the contents of the SASL buffer as defined in RFC 2222 177 * without the leading four octet field that represents the length. 178 * <tt>offset</tt> and <tt>len</tt> specify the portion of <tt>outgoing</tt> 179 * to use. 180 * 181 * @param outgoing A non-null byte array containing the bytes to encode. 182 * @param offset The starting position at <tt>outgoing</tt> of the bytes to use. 183 * @param len The number of bytes from <tt>outgoing</tt> to use. 184 * @return A non-null byte array containing the encoded bytes. 185 * @exception SaslException if <tt>outgoing</tt> cannot be successfully 186 * wrapped. 187 * @exception IllegalStateException if the authentication exchange has 188 * not completed, or if the negotiated quality of protection has 189 * neither integrity nor privacy. 190 */ 191 public abstract byte[] wrap(byte[] outgoing, int offset, int len) 192 throws SaslException; 193 194 /** 195 * Retrieves the negotiated property. 196 * This method can be called only after the authentication exchange has 197 * completed (i.e., when <tt>isComplete()</tt> returns true); otherwise, an 198 * <tt>IllegalStateException</tt> is thrown. 199 * 200 * @param propName the property 201 * @return The value of the negotiated property. If null, the property was 202 * not negotiated or is not applicable to this mechanism. 203 * @exception IllegalStateException if this authentication exchange has not completed 204 */ 205 206 public abstract Object getNegotiatedProperty(String propName); 207 208 /** 209 * Disposes of any system resources or security-sensitive information 210 * the SaslServer might be using. Invoking this method invalidates 211 * the SaslServer instance. This method is idempotent. 212 * @throws SaslException If a problem was encountered while disposing 213 * the resources. 214 */ 215 public abstract void dispose() throws SaslException; 216 }