org.argeo.util/src/org/argeo/util/security/AbstractKeyring.java

   1 /*
   2  * Copyright (C) 2007-2012 Argeo GmbH
   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 package org.argeo.util.security;
  17
  18 import java.io.ByteArrayInputStream;
  19 import java.io.ByteArrayOutputStream;
  20 import java.io.CharArrayWriter;
  21 import java.io.IOException;
  22 import java.io.InputStream;
  23 import java.io.InputStreamReader;
  24 import java.io.OutputStreamWriter;
  25 import java.io.Reader;
  26 import java.io.Writer;
  27 import java.security.AccessController;
  28 import java.security.MessageDigest;
  29 import java.security.Provider;
  30 import java.security.Security;
  31 import java.util.Arrays;
  32 import java.util.Iterator;
  33
  34 import javax.crypto.SecretKey;
  35 import javax.security.auth.Subject;
  36 import javax.security.auth.callback.Callback;
  37 import javax.security.auth.callback.CallbackHandler;
  38 import javax.security.auth.callback.PasswordCallback;
  39 import javax.security.auth.callback.TextOutputCallback;
  40 import javax.security.auth.callback.UnsupportedCallbackException;
  41 import javax.security.auth.login.LoginContext;
  42 import javax.security.auth.login.LoginException;
  43
  44 import org.argeo.util.internal.UtilsException;
  45 import org.argeo.util.internal.StreamUtils;
  46
  47 /** username / password based keyring. TODO internationalize */
  48 public abstract class AbstractKeyring implements Keyring, CryptoKeyring {
  49         public final static String DEFAULT_KEYRING_LOGIN_CONTEXT = "KEYRING";
  50
  51         private String loginContextName = DEFAULT_KEYRING_LOGIN_CONTEXT;
  52         private CallbackHandler defaultCallbackHandler;
  53
  54         private String charset = "UTF-8";
  55
  56         /**
  57          * Default provider is bouncy castle, in order to have consistent behaviour
  58          * across implementations
  59          */
  60         private String securityProviderName = "BC";
  61
  62         /**
  63          * Whether the keyring has already been created in the past with a master
  64          * password
  65          */
  66         protected abstract Boolean isSetup();
  67
  68         /**
  69          * Setup the keyring persistently, {@link #isSetup()} must return true
  70          * afterwards
  71          */
  72         protected abstract void setup(char[] password);
  73
  74         /** Populates the key spec callback */
  75         protected abstract void handleKeySpecCallback(PBEKeySpecCallback pbeCallback);
  76
  77         protected abstract void encrypt(String path, InputStream unencrypted);
  78
  79         protected abstract InputStream decrypt(String path);
  80
  81         /** Triggers lazy initialization */
  82         protected SecretKey getSecretKey() {
  83                 Subject subject = Subject.getSubject(AccessController.getContext());
  84                 // we assume only one secrete key is available
  85                 Iterator<SecretKey> iterator = subject.getPrivateCredentials(
  86                                 SecretKey.class).iterator();
  87                 if (!iterator.hasNext()) {// not initialized
  88                         CallbackHandler callbackHandler = new KeyringCallbackHandler();
  89                         try {
  90                                 LoginContext loginContext = new LoginContext(loginContextName,
  91                                                 subject, callbackHandler);
  92                                 loginContext.login();
  93                                 // FIXME will login even if password is wrong
  94                                 iterator = subject.getPrivateCredentials(SecretKey.class)
  95                                                 .iterator();
  96                                 return iterator.next();
  97                         } catch (LoginException e) {
  98                                 throw new UtilsException("Keyring login failed", e);
  99                         }
 100
 101                 } else {
 102                         SecretKey secretKey = iterator.next();
 103                         if (iterator.hasNext())
 104                                 throw new UtilsException(
 105                                                 "More than one secret key in private credentials");
 106                         return secretKey;
 107                 }
 108         }
 109
 110         public InputStream getAsStream(String path) {
 111                 return decrypt(path);
 112         }
 113
 114         public void set(String path, InputStream in) {
 115                 encrypt(path, in);
 116         }
 117
 118         public char[] getAsChars(String path) {
 119                 InputStream in = getAsStream(path);
 120                 CharArrayWriter writer = null;
 121                 Reader reader = null;
 122                 try {
 123                         writer = new CharArrayWriter();
 124                         reader = new InputStreamReader(in, charset);
 125                         StreamUtils.copy(reader, writer);
 126                         return writer.toCharArray();
 127                 } catch (IOException e) {
 128                         throw new UtilsException("Cannot decrypt to char array", e);
 129                 } finally {
 130                         StreamUtils.closeQuietly(reader);
 131                         StreamUtils.closeQuietly(in);
 132                         StreamUtils.closeQuietly(writer);
 133                 }
 134         }
 135
 136         public void set(String path, char[] arr) {
 137                 ByteArrayOutputStream out = new ByteArrayOutputStream();
 138                 ByteArrayInputStream in = null;
 139                 Writer writer = null;
 140                 try {
 141                         writer = new OutputStreamWriter(out, charset);
 142                         writer.write(arr);
 143                         writer.flush();
 144                         in = new ByteArrayInputStream(out.toByteArray());
 145                         set(path, in);
 146                 } catch (IOException e) {
 147                         throw new UtilsException("Cannot encrypt to char array", e);
 148                 } finally {
 149                         StreamUtils.closeQuietly(writer);
 150                         StreamUtils.closeQuietly(out);
 151                         StreamUtils.closeQuietly(in);
 152                 }
 153         }
 154
 155         protected Provider getSecurityProvider() {
 156                 return Security.getProvider(securityProviderName);
 157         }
 158
 159         public void setLoginContextName(String loginContextName) {
 160                 this.loginContextName = loginContextName;
 161         }
 162
 163         public void setDefaultCallbackHandler(CallbackHandler defaultCallbackHandler) {
 164                 this.defaultCallbackHandler = defaultCallbackHandler;
 165         }
 166
 167         public void setCharset(String charset) {
 168                 this.charset = charset;
 169         }
 170
 171         public void setSecurityProviderName(String securityProviderName) {
 172                 this.securityProviderName = securityProviderName;
 173         }
 174
 175         @Deprecated
 176         protected static byte[] hash(char[] password, byte[] salt,
 177                         Integer iterationCount) {
 178                 ByteArrayOutputStream out = null;
 179                 OutputStreamWriter writer = null;
 180                 try {
 181                         out = new ByteArrayOutputStream();
 182                         writer = new OutputStreamWriter(out, "UTF-8");
 183                         writer.write(password);
 184                         MessageDigest pwDigest = MessageDigest.getInstance("SHA-256");
 185                         pwDigest.reset();
 186                         pwDigest.update(salt);
 187                         byte[] btPass = pwDigest.digest(out.toByteArray());
 188                         for (int i = 0; i < iterationCount; i++) {
 189                                 pwDigest.reset();
 190                                 btPass = pwDigest.digest(btPass);
 191                         }
 192                         return btPass;
 193                 } catch (Exception e) {
 194                         throw new UtilsException("Cannot hash", e);
 195                 } finally {
 196                         StreamUtils.closeQuietly(out);
 197                         StreamUtils.closeQuietly(writer);
 198                 }
 199
 200         }
 201
 202         /**
 203          * Convenience method using the underlying callback to ask for a password
 204          * (typically used when the password is not saved in the keyring)
 205          */
 206         protected char[] ask() {
 207                 PasswordCallback passwordCb = new PasswordCallback("Password", false);
 208                 Callback[] dialogCbs = new Callback[] { passwordCb };
 209                 try {
 210                         defaultCallbackHandler.handle(dialogCbs);
 211                         char[] password = passwordCb.getPassword();
 212                         return password;
 213                 } catch (Exception e) {
 214                         throw new UtilsException("Cannot ask for a password", e);
 215                 }
 216
 217         }
 218
 219         class KeyringCallbackHandler implements CallbackHandler {
 220                 public void handle(Callback[] callbacks) throws IOException,
 221                                 UnsupportedCallbackException {
 222                         // checks
 223                         if (callbacks.length != 2)
 224                                 throw new IllegalArgumentException(
 225                                                 "Keyring required 2 and only 2 callbacks: {PasswordCallback,PBEKeySpecCallback}");
 226                         if (!(callbacks[0] instanceof PasswordCallback))
 227                                 throw new UnsupportedCallbackException(callbacks[0]);
 228                         if (!(callbacks[1] instanceof PBEKeySpecCallback))
 229                                 throw new UnsupportedCallbackException(callbacks[0]);
 230
 231                         PasswordCallback passwordCb = (PasswordCallback) callbacks[0];
 232                         PBEKeySpecCallback pbeCb = (PBEKeySpecCallback) callbacks[1];
 233
 234                         if (isSetup()) {
 235                                 Callback[] dialogCbs = new Callback[] { passwordCb };
 236                                 defaultCallbackHandler.handle(dialogCbs);
 237                         } else {// setup keyring
 238                                 TextOutputCallback textCb1 = new TextOutputCallback(
 239                                                 TextOutputCallback.INFORMATION,
 240                                                 "Enter a master password which will protect your private data");
 241                                 TextOutputCallback textCb2 = new TextOutputCallback(
 242                                                 TextOutputCallback.INFORMATION,
 243                                                 "(for example your credentials to third-party services)");
 244                                 TextOutputCallback textCb3 = new TextOutputCallback(
 245                                                 TextOutputCallback.INFORMATION,
 246                                                 "Don't forget this password since the data cannot be read without it");
 247                                 PasswordCallback confirmPasswordCb = new PasswordCallback(
 248                                                 "Confirm password", false);
 249                                 // first try
 250                                 Callback[] dialogCbs = new Callback[] { textCb1, textCb2,
 251                                                 textCb3, passwordCb, confirmPasswordCb };
 252                                 defaultCallbackHandler.handle(dialogCbs);
 253
 254                                 // if passwords different, retry (except if cancelled)
 255                                 while (passwordCb.getPassword() != null
 256                                                 && !Arrays.equals(passwordCb.getPassword(),
 257                                                                 confirmPasswordCb.getPassword())) {
 258                                         TextOutputCallback textCb = new TextOutputCallback(
 259                                                         TextOutputCallback.ERROR,
 260                                                         "The passwords do not match");
 261                                         dialogCbs = new Callback[] { textCb, passwordCb,
 262                                                         confirmPasswordCb };
 263                                         defaultCallbackHandler.handle(dialogCbs);
 264                                 }
 265
 266                                 if (passwordCb.getPassword() != null) {// not cancelled
 267                                         setup(passwordCb.getPassword());
 268                                 }
 269                         }
 270
 271                         if (passwordCb.getPassword() != null)
 272                                 handleKeySpecCallback(pbeCb);
 273                 }
 274
 275         }
 276 }