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1: /* SecretKeyFactory.java -- Factory for creating secret keys. 2: Copyright (C) 2004 Free Software Foundation, Inc. 3: 4: This file is part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2, or (at your option) 9: any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 USA. 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: 39: package javax.crypto; 40: 41: import gnu.java.security.Engine; 42: 43: import java.lang.reflect.InvocationTargetException; 44: import java.security.InvalidKeyException; 45: import java.security.NoSuchAlgorithmException; 46: import java.security.NoSuchProviderException; 47: import java.security.Provider; 48: import java.security.Security; 49: import java.security.spec.InvalidKeySpecException; 50: import java.security.spec.KeySpec; 51: 52: /** 53: * A secret key factory translates {@link SecretKey} objects to and from 54: * {@link java.security.spec.KeySpec} objects, and can translate between 55: * different vendors' representations of {@link SecretKey} objects (for 56: * security or semantics; whichever applies). 57: * 58: * @author Casey Marshall (csm@gnu.org) 59: * @since 1.4 60: * @see SecretKey 61: */ 62: public class SecretKeyFactory 63: { 64: 65: // Constants and fields. 66: // ------------------------------------------------------------------------ 67: 68: private static final String SERVICE = "SecretKeyFactory"; 69: 70: /** The underlying factory implementation. */ 71: private SecretKeyFactorySpi skfSpi; 72: 73: /** The provider of the implementation. */ 74: private Provider provider; 75: 76: /** The name of the algorithm. */ 77: private String algorithm; 78: 79: // Constructor. 80: // ------------------------------------------------------------------------ 81: 82: /** 83: * Create a new secret key factory. 84: * 85: * @param skfSpi The underlying factory implementation. 86: * @param provider The provider. 87: * @param algorithm The algorithm name. 88: */ 89: protected SecretKeyFactory(SecretKeyFactorySpi skfSpi, Provider provider, 90: String algorithm) 91: { 92: this.skfSpi = skfSpi; 93: this.provider = provider; 94: this.algorithm = algorithm; 95: } 96: 97: // Class methods. 98: // ------------------------------------------------------------------------ 99: 100: /** 101: * Create a new secret key factory from the first appropriate 102: * instance. 103: * 104: * @param algorithm The algorithm name. 105: * @return The appropriate key factory, if found. 106: * @throws java.security.NoSuchAlgorithmException If no provider 107: * implements the specified algorithm. 108: */ 109: public static final SecretKeyFactory getInstance(String algorithm) 110: throws NoSuchAlgorithmException 111: { 112: Provider[] provs = Security.getProviders(); 113: for (int i = 0; i < provs.length; i++) 114: { 115: try 116: { 117: return getInstance(algorithm, provs[i]); 118: } 119: catch (NoSuchAlgorithmException nsae) 120: { 121: } 122: } 123: throw new NoSuchAlgorithmException(algorithm); 124: } 125: 126: /** 127: * Create a new secret key factory from the named provider. 128: * 129: * @param algorithm The algorithm name. 130: * @param provider The provider name. 131: * @return The appropriate key factory, if found. 132: * @throws java.security.NoSuchAlgorithmException If the named 133: * provider does not implement the algorithm. 134: * @throws java.security.NoSuchProviderException If the named provider 135: * does not exist. 136: */ 137: public static final SecretKeyFactory getInstance(String algorithm, 138: String provider) 139: throws NoSuchAlgorithmException, NoSuchProviderException 140: { 141: Provider p = Security.getProvider(provider); 142: if (p == null) 143: { 144: throw new NoSuchProviderException(provider); 145: } 146: return getInstance(algorithm, p); 147: } 148: 149: /** 150: * Create a new secret key factory from the specified provider. 151: * 152: * @param algorithm The algorithm name. 153: * @param provider The provider. 154: * @return The appropriate key factory, if found. 155: * @throws java.security.NoSuchAlgorithmException If the provider 156: * does not implement the algorithm. 157: */ 158: public static final SecretKeyFactory getInstance(String algorithm, 159: Provider provider) 160: throws NoSuchAlgorithmException 161: { 162: try 163: { 164: return new SecretKeyFactory((SecretKeyFactorySpi) 165: Engine.getInstance(SERVICE, algorithm, provider), 166: provider, algorithm); 167: } 168: catch (InvocationTargetException ite) 169: { 170: if (ite.getCause() == null) 171: throw new NoSuchAlgorithmException(algorithm); 172: if (ite.getCause() instanceof NoSuchAlgorithmException) 173: throw (NoSuchAlgorithmException) ite.getCause(); 174: throw new NoSuchAlgorithmException(algorithm); 175: } 176: catch (ClassCastException cce) 177: { 178: throw new NoSuchAlgorithmException(algorithm); 179: } 180: } 181: 182: // Instance methods. 183: // ------------------------------------------------------------------------ 184: 185: /** 186: * Generate a secret key from a key specification, if possible. 187: * 188: * @param keySpec The key specification. 189: * @return The secret key. 190: * @throws java.security.InvalidKeySpecException If the key specification 191: * cannot be transformed into a secret key. 192: */ 193: public final SecretKey generateSecret(KeySpec keySpec) 194: throws InvalidKeySpecException 195: { 196: return skfSpi.engineGenerateSecret(keySpec); 197: } 198: 199: /** 200: * Get the algorithm name. 201: * 202: * @return The algorithm name. 203: */ 204: public final String getAlgorithm() 205: { 206: return algorithm; 207: } 208: 209: /** 210: * Get the key specification from a secret key. 211: * 212: * @param key The secret key. 213: * @param keySpec The target key specification class. 214: * @return The key specification. 215: * @throws java.security.spec.InvalidKeySpecException If the secret key cannot 216: * be transformed into the specified key specification. 217: */ 218: public final KeySpec getKeySpec(SecretKey key, Class keySpec) 219: throws InvalidKeySpecException 220: { 221: return skfSpi.engineGetKeySpec(key, keySpec); 222: } 223: 224: /** 225: * Get the provider of this implementation. 226: * 227: * @return The provider. 228: */ 229: public final Provider getProvider() 230: { 231: return provider; 232: } 233: 234: /** 235: * Translate a secret key into another form. 236: * 237: * @param key The key to translate. 238: * @return The translated key. 239: * @throws java.security.InvalidKeyException If the argument cannot be 240: * translated. 241: */ 242: public final SecretKey translateKey(SecretKey key) 243: throws InvalidKeyException 244: { 245: return skfSpi.engineTranslateKey(key); 246: } 247: }