org.argeo.security.core/src/org/argeo/security/crypto/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.security.crypto;
  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.ArgeoException;
  45 import org.argeo.StreamUtils;
  46 import org.argeo.util.security.Keyring;
  47 import org.bouncycastle.jce.provider.BouncyCastleProvider;
  48
  49 /** username / password based keyring. TODO internationalize */
  50 public abstract class AbstractKeyring implements Keyring, CryptoKeyring {
  51         static {
  52                 Security.addProvider(new BouncyCastleProvider());
  53         }
  54
  55         public final static String DEFAULT_KEYRING_LOGIN_CONTEXT = "KEYRING";
  56
  57         private String loginContextName = DEFAULT_KEYRING_LOGIN_CONTEXT;
  58         private CallbackHandler defaultCallbackHandler;
  59
  60         private String charset = "UTF-8";
  61
  62         /**
  63          * Default provider is bouncy castle, in order to have consistent behaviour
  64          * across implementations
  65          */
  66         private String securityProviderName = "BC";
  67
  68         /**
  69          * Whether the keyring has already been created in the past with a master
  70          * password
  71          */
  72         protected abstract Boolean isSetup();
  73
  74         /**
  75          * Setup the keyring persistently, {@link #isSetup()} must return true
  76          * afterwards
  77          */
  78         protected abstract void setup(char[] password);
  79
  80         /** Populates the key spec callback */
  81         protected abstract void handleKeySpecCallback(PBEKeySpecCallback pbeCallback);
  82
  83         protected abstract void encrypt(String path, InputStream unencrypted);
  84
  85         protected abstract InputStream decrypt(String path);
  86
  87         /** Triggers lazy initialization */
  88         protected SecretKey getSecretKey() {
  89                 Subject subject = Subject.getSubject(AccessController.getContext());
  90                 // we assume only one secrete key is available
  91                 Iterator<SecretKey> iterator = subject.getPrivateCredentials(
  92                                 SecretKey.class).iterator();
  93                 if (!iterator.hasNext()) {// not initialized
  94                         CallbackHandler callbackHandler = new KeyringCallbackHandler();
  95                         try {
  96                                 LoginContext loginContext = new LoginContext(loginContextName,
  97                                                 subject, callbackHandler);
  98                                 loginContext.login();
  99                                 // FIXME will login even if password is wrong
 100                                 iterator = subject.getPrivateCredentials(SecretKey.class)
 101                                                 .iterator();
 102                                 return iterator.next();
 103                         } catch (LoginException e) {
 104                                 throw new ArgeoException("Keyring login failed", e);
 105                         }
 106
 107                 } else {
 108                         SecretKey secretKey = iterator.next();
 109                         if (iterator.hasNext())
 110                                 throw new ArgeoException(
 111                                                 "More than one secret key in private credentials");
 112                         return secretKey;
 113                 }
 114         }
 115
 116         public InputStream getAsStream(String path) {
 117                 return decrypt(path);
 118         }
 119
 120         public void set(String path, InputStream in) {
 121                 encrypt(path, in);
 122         }
 123
 124         public char[] getAsChars(String path) {
 125                 InputStream in = getAsStream(path);
 126                 CharArrayWriter writer = null;
 127                 Reader reader = null;
 128                 try {
 129                         writer = new CharArrayWriter();
 130                         reader = new InputStreamReader(in, charset);
 131                         StreamUtils.copy(reader, writer);
 132                         return writer.toCharArray();
 133                 } catch (IOException e) {
 134                         throw new ArgeoException("Cannot decrypt to char array", e);
 135                 } finally {
 136                         StreamUtils.closeQuietly(reader);
 137                         StreamUtils.closeQuietly(in);
 138                         StreamUtils.closeQuietly(writer);
 139                 }
 140         }
 141
 142         public void set(String path, char[] arr) {
 143                 ByteArrayOutputStream out = new ByteArrayOutputStream();
 144                 ByteArrayInputStream in = null;
 145                 Writer writer = null;
 146                 try {
 147                         writer = new OutputStreamWriter(out, charset);
 148                         writer.write(arr);
 149                         writer.flush();
 150                         in = new ByteArrayInputStream(out.toByteArray());
 151                         set(path, in);
 152                 } catch (IOException e) {
 153                         throw new ArgeoException("Cannot encrypt to char array", e);
 154                 } finally {
 155                         StreamUtils.closeQuietly(writer);
 156                         StreamUtils.closeQuietly(out);
 157                         StreamUtils.closeQuietly(in);
 158                 }
 159         }
 160
 161         protected Provider getSecurityProvider() {
 162                 return Security.getProvider(securityProviderName);
 163         }
 164
 165         public void setLoginContextName(String loginContextName) {
 166                 this.loginContextName = loginContextName;
 167         }
 168
 169         public void setDefaultCallbackHandler(CallbackHandler defaultCallbackHandler) {
 170                 this.defaultCallbackHandler = defaultCallbackHandler;
 171         }
 172
 173         public void setCharset(String charset) {
 174                 this.charset = charset;
 175         }
 176
 177         public void setSecurityProviderName(String securityProviderName) {
 178                 this.securityProviderName = securityProviderName;
 179         }
 180
 181         @Deprecated
 182         protected static byte[] hash(char[] password, byte[] salt,
 183                         Integer iterationCount) {
 184                 ByteArrayOutputStream out = null;
 185                 OutputStreamWriter writer = null;
 186                 try {
 187                         out = new ByteArrayOutputStream();
 188                         writer = new OutputStreamWriter(out, "UTF-8");
 189                         writer.write(password);
 190                         MessageDigest pwDigest = MessageDigest.getInstance("SHA-256");
 191                         pwDigest.reset();
 192                         pwDigest.update(salt);
 193                         byte[] btPass = pwDigest.digest(out.toByteArray());
 194                         for (int i = 0; i < iterationCount; i++) {
 195                                 pwDigest.reset();
 196                                 btPass = pwDigest.digest(btPass);
 197                         }
 198                         return btPass;
 199                 } catch (Exception e) {
 200                         throw new ArgeoException("Cannot hash", e);
 201                 } finally {
 202                         StreamUtils.closeQuietly(out);
 203                         StreamUtils.closeQuietly(writer);
 204                 }
 205
 206         }
 207
 208         /**
 209          * Convenience method using the underlying callback to ask for a password
 210          * (typically used when the password is not saved in the keyring)
 211          */
 212         protected char[] ask() {
 213                 PasswordCallback passwordCb = new PasswordCallback("Password", false);
 214                 Callback[] dialogCbs = new Callback[] { passwordCb };
 215                 try {
 216                         defaultCallbackHandler.handle(dialogCbs);
 217                         char[] password = passwordCb.getPassword();
 218                         return password;
 219                 } catch (Exception e) {
 220                         throw new ArgeoException("Cannot ask for a password", e);
 221                 }
 222
 223         }
 224
 225         class KeyringCallbackHandler implements CallbackHandler {
 226                 public void handle(Callback[] callbacks) throws IOException,
 227                                 UnsupportedCallbackException {
 228                         // checks
 229                         if (callbacks.length != 2)
 230                                 throw new IllegalArgumentException(
 231                                                 "Keyring required 2 and only 2 callbacks: {PasswordCallback,PBEKeySpecCallback}");
 232                         if (!(callbacks[0] instanceof PasswordCallback))
 233                                 throw new UnsupportedCallbackException(callbacks[0]);
 234                         if (!(callbacks[1] instanceof PBEKeySpecCallback))
 235                                 throw new UnsupportedCallbackException(callbacks[0]);
 236
 237                         PasswordCallback passwordCb = (PasswordCallback) callbacks[0];
 238                         PBEKeySpecCallback pbeCb = (PBEKeySpecCallback) callbacks[1];
 239
 240                         if (isSetup()) {
 241                                 Callback[] dialogCbs = new Callback[] { passwordCb };
 242                                 defaultCallbackHandler.handle(dialogCbs);
 243                         } else {// setup keyring
 244                                 TextOutputCallback textCb1 = new TextOutputCallback(
 245                                                 TextOutputCallback.INFORMATION,
 246                                                 "Enter a master password which will protect your private data");
 247                                 TextOutputCallback textCb2 = new TextOutputCallback(
 248                                                 TextOutputCallback.INFORMATION,
 249                                                 "(for example your credentials to third-party services)");
 250                                 TextOutputCallback textCb3 = new TextOutputCallback(
 251                                                 TextOutputCallback.INFORMATION,
 252                                                 "Don't forget this password since the data cannot be read without it");
 253                                 PasswordCallback confirmPasswordCb = new PasswordCallback(
 254                                                 "Confirm password", false);
 255                                 // first try
 256                                 Callback[] dialogCbs = new Callback[] { textCb1, textCb2,
 257                                                 textCb3, passwordCb, confirmPasswordCb };
 258                                 defaultCallbackHandler.handle(dialogCbs);
 259
 260                                 // if passwords different, retry (except if cancelled)
 261                                 while (passwordCb.getPassword() != null
 262                                                 && !Arrays.equals(passwordCb.getPassword(),
 263                                                                 confirmPasswordCb.getPassword())) {
 264                                         TextOutputCallback textCb = new TextOutputCallback(
 265                                                         TextOutputCallback.ERROR,
 266                                                         "The passwords do not match");
 267                                         dialogCbs = new Callback[] { textCb, passwordCb,
 268                                                         confirmPasswordCb };
 269                                         defaultCallbackHandler.handle(dialogCbs);
 270                                 }
 271
 272                                 if (passwordCb.getPassword() != null) {// not cancelled
 273                                         setup(passwordCb.getPassword());
 274                                 }
 275                         }
 276
 277                         if (passwordCb.getPassword() != null)
 278                                 handleKeySpecCallback(pbeCb);
 279                 }
 280
 281         }
 282 }