src/com/owncloud/android/network/SslAnalyzer.java

   1 /* ownCloud Android client application
   2  *   Copyright (C) 2011  Bartek Przybylski
   3  *
   4  *   This program is free software: you can redistribute it and/or modify
   5  *   it under the terms of the GNU General Public License as published by
   6  *   the Free Software Foundation, either version 3 of the License, or
   7  *   (at your option) any later version.
   8  *
   9  *   This program is distributed in the hope that it will be useful,
  10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *   GNU General Public License for more details.
  13  *
  14  *   You should have received a copy of the GNU General Public License
  15  *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17 package com.owncloud.android.network;
  18
  19 import java.security.cert.CertPathValidatorException;
  20 import java.security.cert.CertificateExpiredException;
  21 import java.security.cert.CertificateNotYetValidException;
  22
  23 import javax.net.ssl.SSLException;
  24 import javax.net.ssl.SSLPeerUnverifiedException;
  25
  26 import com.owncloud.android.operations.RemoteOperationResult;
  27
  28 /**
  29  * Helper class to check if a SSL error is related to a condition that could be avoided with assistance from the user.
  30  *
  31  * @author David A. Velasco
  32  */
  33 public class SslAnalyzer {
  34
  35     /**
  36      * Search for a SSL-related exception in a remote operation result that can be recoverable
  37      * by allowing the user to state the reliability of the certificate from the server.
  38      *
  39      * @param result        Result of a remote operation.
  40      * @return              An exception instance that caused the failure of the remote operation and that can be avoided if the user
  41      *                      states the certificate from the server as reliable; or NULL if the result is that's not possible
  42      */
  43     public static Exception getRecoverableException(RemoteOperationResult result) {
  44         Exception ret = null;
  45         SSLException e = (SSLException)result.getException();
  46         Throwable cause = null;
  47         if (e != null) {
  48             if (e instanceof SSLPeerUnverifiedException) {
  49                 ret = e;
  50
  51             } else {
  52                 cause = e.getCause();
  53                 Throwable previousCause = null;
  54                 boolean recoverableCertException = false;
  55                 while (cause != null && cause != previousCause && !recoverableCertException) {     // getCause() is not funny
  56                     recoverableCertException = (  cause instanceof CertPathValidatorException ||
  57                                                 cause instanceof CertificateExpiredException ||
  58                                                 cause instanceof CertificateNotYetValidException );
  59                     if (recoverableCertException)
  60                         ret = (Exception)cause;
  61                     previousCause = cause;
  62                     cause = cause.getCause();
  63                 }
  64             }
  65         }
  66         return ret;
  67     }
  68
  69
  70     /**
  71      * Checks if a remote operation result can be recoverable
  72      * by allowing the user to state the reliability of the certificate from the server.
  73      *
  74      * @param result        Result of a remote operation.
  75      * @return              An exception instance that caused the failure of the remote operation and that can be avoided if the user
  76      *                      states the certificate from the server as reliable; or NULL if the result is that's not possible
  77      */
  78     public static boolean isRecoverable(RemoteOperationResult result) {
  79         return (getRecoverableException(result) != null);
  80     }
  81
  82 }