1 /* AlgorithmParameters.java --- Algorithm Parameters Implementation Class 2 Copyright (C) 1999, 2003, 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 java.security; 40 41 import gnu.java.lang.CPStringBuilder; 42 43 import gnu.java.security.Engine; 44 45 import java.io.IOException; 46 import java.lang.reflect.InvocationTargetException; 47 import java.security.spec.AlgorithmParameterSpec; 48 import java.security.spec.InvalidParameterSpecException; 49 50 /** 51 * <code>AlgorithmParameters</code> is an Algorithm Parameters class which 52 * provides an interface through which the user can manage the parameters of an 53 * Algorithm. 54 * 55 * @author Mark Benvenuto 56 * @since 1.2 57 * @see AlgorithmParameterSpec 58 * @see java.security.spec.DSAParameterSpec 59 * @see KeyPairGenerator 60 */ 61 public class AlgorithmParameters 62 { 63 /** Service name for algorithm parameters. */ 64 private static final String ALGORITHM_PARAMETERS = "AlgorithmParameters"; 65 66 private AlgorithmParametersSpi paramSpi; 67 private Provider provider; 68 private String algorithm; 69 70 /** 71 * Constructs a new instance of <code>AlgorithmParameters</code>. 72 * 73 * @param paramSpi 74 * the engine to use. 75 * @param provider 76 * the provider to use. 77 * @param algorithm 78 * the algorithm to use. 79 */ AlgorithmParameters(AlgorithmParametersSpi paramSpi, Provider provider, String algorithm)80 protected AlgorithmParameters(AlgorithmParametersSpi paramSpi, 81 Provider provider, String algorithm) 82 { 83 this.paramSpi = paramSpi; 84 this.provider = provider; 85 this.algorithm = algorithm; 86 } 87 88 /** @return A string with the name of the algorithm used. */ getAlgorithm()89 public final String getAlgorithm() 90 { 91 return algorithm; 92 } 93 94 /** 95 * Returns a new instance of <code>AlgorithmParameters</code> representing 96 * the specified algorithm parameters. 97 * <p> 98 * The returned <code>AlgorithmParameters</code> must still be initialized 99 * with an <code>init()</code> method. 100 * 101 * @param algorithm the algorithm to use. 102 * @return the new instance repesenting the desired algorithm. 103 * @throws NoSuchAlgorithmException if the algorithm is not implemented by any 104 * provider. 105 * @throws IllegalArgumentException if <code>algorithm</code> is 106 * <code>null</code> or is an empty string. 107 */ getInstance(String algorithm)108 public static AlgorithmParameters getInstance(String algorithm) 109 throws NoSuchAlgorithmException 110 { 111 Provider[] p = Security.getProviders(); 112 NoSuchAlgorithmException lastException = null; 113 for (int i = 0; i < p.length; i++) 114 try 115 { 116 return getInstance(algorithm, p[i]); 117 } 118 catch (NoSuchAlgorithmException x) 119 { 120 lastException = x; 121 } 122 if (lastException != null) 123 throw lastException; 124 throw new NoSuchAlgorithmException(algorithm); 125 } 126 127 /** 128 * Returns a new instance of <code>AlgorithmParameters</code> representing 129 * the specified algorithm parameters from a named provider. 130 * <p> 131 * The returned <code>AlgorithmParameters</code> must still be intialized 132 * with an <code>init()</code> method. 133 * </p> 134 * 135 * @param algorithm the algorithm to use. 136 * @param provider the name of the {@link Provider} to use. 137 * @return the new instance repesenting the desired algorithm. 138 * @throws NoSuchAlgorithmException if the algorithm is not implemented by the 139 * named provider. 140 * @throws NoSuchProviderException if the named provider was not found. 141 * @throws IllegalArgumentException if either <code>algorithm</code> or 142 * <code>provider</code> is <code>null</code> or empty. 143 */ getInstance(String algorithm, String provider)144 public static AlgorithmParameters getInstance(String algorithm, 145 String provider) 146 throws NoSuchAlgorithmException, NoSuchProviderException 147 { 148 if (provider == null) 149 throw new IllegalArgumentException("provider MUST NOT be null"); 150 provider = provider.trim(); 151 if (provider.length() == 0) 152 throw new IllegalArgumentException("provider MUST NOT be empty"); 153 Provider p = Security.getProvider(provider); 154 if (p == null) 155 throw new NoSuchProviderException(provider); 156 return getInstance(algorithm, p); 157 } 158 159 /** 160 * Returns a new instance of <code>AlgorithmParameters</code> representing 161 * the specified algorithm parameters from the specified {@link Provider}. 162 * <p> 163 * The returned <code>AlgorithmParameters</code> must still be intialized 164 * with an <code>init()</code> method. 165 * 166 * @param algorithm the algorithm to use. 167 * @param provider the {@link Provider} to use. 168 * @return the new instance repesenting the desired algorithm. 169 * @throws NoSuchAlgorithmException if the algorithm is not implemented by the 170 * {@link Provider}. 171 * @throws IllegalArgumentException if either <code>algorithm</code> or 172 * <code>provider</code> is <code>null</code>, or if 173 * <code>algorithm</code> is an empty string. 174 * @since 1.4 175 */ getInstance(String algorithm, Provider provider)176 public static AlgorithmParameters getInstance(String algorithm, 177 Provider provider) 178 throws NoSuchAlgorithmException 179 { 180 CPStringBuilder sb = new CPStringBuilder("AlgorithmParameters for algorithm [") 181 .append(algorithm).append("] from provider[") 182 .append(provider).append("] could not be created"); 183 Throwable cause; 184 try 185 { 186 Object spi = Engine.getInstance(ALGORITHM_PARAMETERS, algorithm, provider); 187 return new AlgorithmParameters((AlgorithmParametersSpi) spi, 188 provider, 189 algorithm); 190 } 191 catch (InvocationTargetException x) 192 { 193 cause = x.getCause(); 194 if (cause instanceof NoSuchAlgorithmException) 195 throw (NoSuchAlgorithmException) cause; 196 if (cause == null) 197 cause = x; 198 } 199 catch (ClassCastException x) 200 { 201 cause = x; 202 } 203 NoSuchAlgorithmException x = new NoSuchAlgorithmException(sb.toString()); 204 x.initCause(cause); 205 throw x; 206 } 207 208 /** @return the provider of this parameter object. */ getProvider()209 public final Provider getProvider() 210 { 211 return provider; 212 } 213 214 /** 215 * Initializes the engine with the specified {@link AlgorithmParameterSpec}. 216 * 217 * @param paramSpec 218 * A {@link AlgorithmParameterSpec} to use. 219 * @throws InvalidParameterSpecException 220 * if <code>paramSpec</code> is invalid. 221 */ init(AlgorithmParameterSpec paramSpec)222 public final void init(AlgorithmParameterSpec paramSpec) 223 throws InvalidParameterSpecException 224 { 225 paramSpi.engineInit(paramSpec); 226 } 227 228 /** 229 * Initializes the engine with the specified parameters stored in the byte 230 * array and decodes them according to the ASN.1 specification. If the ASN.1 231 * specification exists then it succeeds otherwise an {@link IOException} is 232 * thrown. 233 * 234 * @param params 235 * the parameters to use. 236 * @throws IOException 237 * if a decoding error occurs. 238 */ init(byte[]params)239 public final void init(byte[]params) throws IOException 240 { 241 paramSpi.engineInit(params); 242 } 243 244 /** 245 * Initializes the engine with the specified parameters stored in the byte 246 * array and decodes them according to the specified decoding specification. 247 * If <code>format</code> is <code>null</code>, then this method decodes the 248 * byte array using the ASN.1 specification if it exists, otherwise it throws 249 * an {@link IOException}. 250 * 251 * @param params 252 * the parameters to use. 253 * @param format 254 * the name of decoding format to use. 255 * @throws IOException 256 * if a decoding error occurs. 257 */ init(byte[]params, String format)258 public final void init(byte[]params, String format) throws IOException 259 { 260 paramSpi.engineInit(params, format); 261 } 262 263 /** 264 * Returns a new instance of <code>AlgorithmParameters</code> as a 265 * designated parameter specification {@link Class}. 266 * 267 * @param paramSpec 268 * the {@link Class} to use. 269 * @return the parameter specification. 270 * @throws InvalidParameterSpecException 271 * if <code>paramSpec</code> is invalid. 272 */ 273 public final <T extends AlgorithmParameterSpec> getParameterSpec(Class<T> paramSpec)274 T getParameterSpec(Class<T> paramSpec) 275 throws InvalidParameterSpecException 276 { 277 return paramSpi.engineGetParameterSpec(paramSpec); 278 } 279 280 /** 281 * Returns the parameters in the default encoding format. The primary encoding 282 * format is ASN.1 if it exists for the specified type. 283 * 284 * @return byte array representing the parameters. 285 */ getEncoded()286 public final byte[] getEncoded() throws IOException 287 { 288 return paramSpi.engineGetEncoded(); 289 } 290 291 /** 292 * Returns the parameters in the specified encoding format. If 293 * <code>format</code> is <code>null</code> then the ASN.1 encoding 294 * format is used if it exists for the specified type. 295 * 296 * @param format 297 * the name of the encoding format to use. 298 * @return the parameters encoded using the specified encoding scheme. 299 * @throws IOException 300 * if an encoding exception occurs, or if this parameter object has 301 * not been initialized. 302 */ getEncoded(String format)303 public final byte[] getEncoded(String format) throws IOException 304 { 305 return paramSpi.engineGetEncoded(format); 306 } 307 308 /** 309 * Returns a string representation of the encoded form. 310 * 311 * @return a string representation of the encoded form. 312 */ toString()313 public final String toString() 314 { 315 return paramSpi.engineToString(); 316 } 317 } 318