Home | History | Annotate | Download | only in eap 
      1 /*
      2  * Copyright (C) 2016 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.server.wifi.hotspot2.anqp.eap;
     18 
     19 import com.android.internal.annotations.VisibleForTesting;
     20 
     21 import java.net.ProtocolException;
     22 import java.nio.BufferUnderflowException;
     23 import java.nio.ByteBuffer;
     24 import java.util.Collections;
     25 import java.util.HashMap;
     26 import java.util.HashSet;
     27 import java.util.Map;
     28 import java.util.Set;
     29 
     30 /**
     31  * An EAP Method part of the NAI Realm ANQP element, specified in
     32  * IEEE802.11-2012 section 8.4.4.10, figure 8-420
     33  *
     34  * Format:
     35  * | Length | EAP Method | Auth Param Count | Auth Param #1 (optional) | ....
     36  *     1          1               1                 variable
     37  */
     38 public class EAPMethod {
     39     private final int mEAPMethodID;
     40     private final Map<Integer, Set<AuthParam>> mAuthParams;
     41 
     42     @VisibleForTesting
     43     public EAPMethod(int methodID, Map<Integer, Set<AuthParam>> authParams) {
     44         mEAPMethodID = methodID;
     45         mAuthParams = authParams;
     46     }
     47 
     48     /**
     49      * Parse a EAPMethod from the given buffer.
     50      *
     51      * @param payload The byte buffer to read from
     52      * @return {@link EAPMethod}
     53      * @throws ProtocolException
     54      * @throws BufferUnderflowException
     55      */
     56     public static EAPMethod parse(ByteBuffer payload) throws ProtocolException {
     57         // Read and verify the length field.
     58         int length = payload.get() & 0xFF;
     59         if (length > payload.remaining()) {
     60             throw new ProtocolException("Invalid data length: " + length);
     61         }
     62 
     63         int methodID = payload.get() & 0xFF;
     64         int authCount = payload.get() & 0xFF;
     65         Map<Integer, Set<AuthParam>> authParams = new HashMap<>();
     66         while (authCount > 0) {
     67             addAuthParam(authParams, parseAuthParam(payload));
     68             authCount--;
     69         }
     70         return new EAPMethod(methodID, authParams);
     71     }
     72 
     73     /**
     74      * Parse a AuthParam from the given buffer.
     75      *
     76      * Format:
     77      * | Auth ID | Length | Value |
     78      *      1         1    variable
     79      *
     80      * @param payload The byte buffer to read from
     81      * @return {@link AuthParam}
     82      * @throws BufferUnderflowException
     83      * @throws ProtocolException
     84      */
     85     private static AuthParam parseAuthParam(ByteBuffer payload) throws ProtocolException {
     86         int authID = payload.get() & 0xFF;
     87         int length = payload.get() & 0xFF;
     88         switch (authID) {
     89             case AuthParam.PARAM_TYPE_EXPANDED_EAP_METHOD:
     90                 return ExpandedEAPMethod.parse(payload, length, false);
     91             case AuthParam.PARAM_TYPE_NON_EAP_INNER_AUTH_TYPE:
     92                 return NonEAPInnerAuth.parse(payload, length);
     93             case AuthParam.PARAM_TYPE_INNER_AUTH_EAP_METHOD_TYPE:
     94                 return InnerAuthEAP.parse(payload, length);
     95             case AuthParam.PARAM_TYPE_EXPANDED_INNER_EAP_METHOD:
     96                 return ExpandedEAPMethod.parse(payload, length, true);
     97             case AuthParam.PARAM_TYPE_CREDENTIAL_TYPE:
     98                 return CredentialType.parse(payload, length, false);
     99             case AuthParam.PARAM_TYPE_TUNNELED_EAP_METHOD_CREDENTIAL_TYPE:
    100                 return CredentialType.parse(payload, length, true);
    101             case AuthParam.PARAM_TYPE_VENDOR_SPECIFIC:
    102                 return VendorSpecificAuth.parse(payload, length);
    103             default:
    104                 throw new ProtocolException("Unknow Auth Type ID: " + authID);
    105         }
    106     }
    107 
    108     /**
    109      * Add an AuthParam to a map of authentication parameters.  It is possible to have
    110      * multiple authentication parameters for the same type.
    111      *
    112      * @param paramsMap The authentication parameter map to add the new parameter to
    113      * @param authParam The authentication parameter to add
    114      */
    115     private static void addAuthParam(Map<Integer, Set<AuthParam>> paramsMap,
    116             AuthParam authParam) {
    117         Set<AuthParam> authParams = paramsMap.get(authParam.getAuthTypeID());
    118         if (authParams == null) {
    119             authParams = new HashSet<>();
    120             paramsMap.put(authParam.getAuthTypeID(), authParams);
    121         }
    122         authParams.add(authParam);
    123     }
    124 
    125     public Map<Integer, Set<AuthParam>> getAuthParams() {
    126         return Collections.unmodifiableMap(mAuthParams);
    127     }
    128 
    129     public int getEAPMethodID() {
    130         return mEAPMethodID;
    131     }
    132 
    133     @Override
    134     public boolean equals(Object thatObject) {
    135         if (thatObject == this) {
    136             return true;
    137         }
    138         if (!(thatObject instanceof EAPMethod)) {
    139             return false;
    140         }
    141         EAPMethod that = (EAPMethod) thatObject;
    142         return mEAPMethodID == that.mEAPMethodID && mAuthParams.equals(that.mAuthParams);
    143     }
    144 
    145     @Override
    146     public int hashCode() {
    147         return mEAPMethodID * 31 + mAuthParams.hashCode();
    148     }
    149 
    150     @Override
    151     public String toString() {
    152         return "EAPMethod{mEAPMethodID=" + mEAPMethodID + " mAuthParams=" + mAuthParams + "}";
    153     }
    154 }
    155