001 /* AlgorithmParameters.java --- Algorithm Parameters Implementation Class 002 Copyright (C) 1999, 2003, 2004 Free Software Foundation, Inc. 003 004 This file is part of GNU Classpath. 005 006 GNU Classpath is free software; you can redistribute it and/or modify 007 it under the terms of the GNU General Public License as published by 008 the Free Software Foundation; either version 2, or (at your option) 009 any later version. 010 011 GNU Classpath is distributed in the hope that it will be useful, but 012 WITHOUT ANY WARRANTY; without even the implied warranty of 013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014 General Public License for more details. 015 016 You should have received a copy of the GNU General Public License 017 along with GNU Classpath; see the file COPYING. If not, write to the 018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 019 02110-1301 USA. 020 021 Linking this library statically or dynamically with other modules is 022 making a combined work based on this library. Thus, the terms and 023 conditions of the GNU General Public License cover the whole 024 combination. 025 026 As a special exception, the copyright holders of this library give you 027 permission to link this library with independent modules to produce an 028 executable, regardless of the license terms of these independent 029 modules, and to copy and distribute the resulting executable under 030 terms of your choice, provided that you also meet, for each linked 031 independent module, the terms and conditions of the license of that 032 module. An independent module is a module which is not derived from 033 or based on this library. If you modify this library, you may extend 034 this exception to your version of the library, but you are not 035 obligated to do so. If you do not wish to do so, delete this 036 exception statement from your version. */ 037 038 039 package java.security; 040 041 import gnu.java.security.Engine; 042 043 import java.io.IOException; 044 import java.lang.reflect.InvocationTargetException; 045 import java.security.spec.AlgorithmParameterSpec; 046 import java.security.spec.InvalidParameterSpecException; 047 048 /** 049 * <code>AlgorithmParameters</code> is an Algorithm Parameters class which 050 * provides an interface through which the user can manage the parameters of an 051 * Algorithm. 052 * 053 * @author Mark Benvenuto 054 * @since 1.2 055 * @see AlgorithmParameterSpec 056 * @see java.security.spec.DSAParameterSpec 057 * @see KeyPairGenerator 058 */ 059 public class AlgorithmParameters 060 { 061 /** Service name for algorithm parameters. */ 062 private static final String ALGORITHM_PARAMETERS = "AlgorithmParameters"; 063 064 private AlgorithmParametersSpi paramSpi; 065 private Provider provider; 066 private String algorithm; 067 068 /** 069 * Constructs a new instance of <code>AlgorithmParameters</code>. 070 * 071 * @param paramSpi 072 * the engine to use. 073 * @param provider 074 * the provider to use. 075 * @param algorithm 076 * the algorithm to use. 077 */ 078 protected AlgorithmParameters(AlgorithmParametersSpi paramSpi, 079 Provider provider, String algorithm) 080 { 081 this.paramSpi = paramSpi; 082 this.provider = provider; 083 this.algorithm = algorithm; 084 } 085 086 /** @return A string with the name of the algorithm used. */ 087 public final String getAlgorithm() 088 { 089 return algorithm; 090 } 091 092 /** 093 * Returns a new instance of <code>AlgorithmParameters</code> representing 094 * the specified algorithm parameters. 095 * <p> 096 * The returned <code>AlgorithmParameters</code> must still be initialized 097 * with an <code>init()</code> method. 098 * 099 * @param algorithm the algorithm to use. 100 * @return the new instance repesenting the desired algorithm. 101 * @throws NoSuchAlgorithmException if the algorithm is not implemented by any 102 * provider. 103 * @throws IllegalArgumentException if <code>algorithm</code> is 104 * <code>null</code> or is an empty string. 105 */ 106 public static AlgorithmParameters getInstance(String algorithm) 107 throws NoSuchAlgorithmException 108 { 109 Provider[] p = Security.getProviders(); 110 NoSuchAlgorithmException lastException = null; 111 for (int i = 0; i < p.length; i++) 112 try 113 { 114 return getInstance(algorithm, p[i]); 115 } 116 catch (NoSuchAlgorithmException x) 117 { 118 lastException = x; 119 } 120 if (lastException != null) 121 throw lastException; 122 throw new NoSuchAlgorithmException(algorithm); 123 } 124 125 /** 126 * Returns a new instance of <code>AlgorithmParameters</code> representing 127 * the specified algorithm parameters from a named provider. 128 * <p> 129 * The returned <code>AlgorithmParameters</code> must still be intialized 130 * with an <code>init()</code> method. 131 * </p> 132 * 133 * @param algorithm the algorithm to use. 134 * @param provider the name of the {@link Provider} to use. 135 * @return the new instance repesenting the desired algorithm. 136 * @throws NoSuchAlgorithmException if the algorithm is not implemented by the 137 * named provider. 138 * @throws NoSuchProviderException if the named provider was not found. 139 * @throws IllegalArgumentException if either <code>algorithm</code> or 140 * <code>provider</code> is <code>null</code> or empty. 141 */ 142 public static AlgorithmParameters getInstance(String algorithm, 143 String provider) 144 throws NoSuchAlgorithmException, NoSuchProviderException 145 { 146 if (provider == null) 147 throw new IllegalArgumentException("provider MUST NOT be null"); 148 provider = provider.trim(); 149 if (provider.length() == 0) 150 throw new IllegalArgumentException("provider MUST NOT be empty"); 151 Provider p = Security.getProvider(provider); 152 if (p == null) 153 throw new NoSuchProviderException(provider); 154 return getInstance(algorithm, p); 155 } 156 157 /** 158 * Returns a new instance of <code>AlgorithmParameters</code> representing 159 * the specified algorithm parameters from the specified {@link Provider}. 160 * <p> 161 * The returned <code>AlgorithmParameters</code> must still be intialized 162 * with an <code>init()</code> method. 163 * 164 * @param algorithm the algorithm to use. 165 * @param provider the {@link Provider} to use. 166 * @return the new instance repesenting the desired algorithm. 167 * @throws NoSuchAlgorithmException if the algorithm is not implemented by the 168 * {@link Provider}. 169 * @throws IllegalArgumentException if either <code>algorithm</code> or 170 * <code>provider</code> is <code>null</code>, or if 171 * <code>algorithm</code> is an empty string. 172 * @since 1.4 173 */ 174 public static AlgorithmParameters getInstance(String algorithm, 175 Provider provider) 176 throws NoSuchAlgorithmException 177 { 178 StringBuilder sb = new StringBuilder("AlgorithmParameters for algorithm [") 179 .append(algorithm).append("] from provider[") 180 .append(provider).append("] could not be created"); 181 Throwable cause; 182 try 183 { 184 Object spi = Engine.getInstance(ALGORITHM_PARAMETERS, algorithm, provider); 185 return new AlgorithmParameters((AlgorithmParametersSpi) spi, 186 provider, 187 algorithm); 188 } 189 catch (InvocationTargetException x) 190 { 191 cause = x.getCause(); 192 if (cause instanceof NoSuchAlgorithmException) 193 throw (NoSuchAlgorithmException) cause; 194 if (cause == null) 195 cause = x; 196 } 197 catch (ClassCastException x) 198 { 199 cause = x; 200 } 201 NoSuchAlgorithmException x = new NoSuchAlgorithmException(sb.toString()); 202 x.initCause(cause); 203 throw x; 204 } 205 206 /** @return the provider of this parameter object. */ 207 public final Provider getProvider() 208 { 209 return provider; 210 } 211 212 /** 213 * Initializes the engine with the specified {@link AlgorithmParameterSpec}. 214 * 215 * @param paramSpec 216 * A {@link AlgorithmParameterSpec} to use. 217 * @throws InvalidParameterSpecException 218 * if <code>paramSpec</code> is invalid. 219 */ 220 public final void init(AlgorithmParameterSpec paramSpec) 221 throws InvalidParameterSpecException 222 { 223 paramSpi.engineInit(paramSpec); 224 } 225 226 /** 227 * Initializes the engine with the specified parameters stored in the byte 228 * array and decodes them according to the ASN.1 specification. If the ASN.1 229 * specification exists then it succeeds otherwise an {@link IOException} is 230 * thrown. 231 * 232 * @param params 233 * the parameters to use. 234 * @throws IOException 235 * if a decoding error occurs. 236 */ 237 public final void init(byte[]params) throws IOException 238 { 239 paramSpi.engineInit(params); 240 } 241 242 /** 243 * Initializes the engine with the specified parameters stored in the byte 244 * array and decodes them according to the specified decoding specification. 245 * If <code>format</code> is <code>null</code>, then this method decodes the 246 * byte array using the ASN.1 specification if it exists, otherwise it throws 247 * an {@link IOException}. 248 * 249 * @param params 250 * the parameters to use. 251 * @param format 252 * the name of decoding format to use. 253 * @throws IOException 254 * if a decoding error occurs. 255 */ 256 public final void init(byte[]params, String format) throws IOException 257 { 258 paramSpi.engineInit(params, format); 259 } 260 261 /** 262 * Returns a new instance of <code>AlgorithmParameters</code> as a 263 * designated parameter specification {@link Class}. 264 * 265 * @param paramSpec 266 * the {@link Class} to use. 267 * @return the parameter specification. 268 * @throws InvalidParameterSpecException 269 * if <code>paramSpec</code> is invalid. 270 */ 271 public final <T extends AlgorithmParameterSpec> 272 T getParameterSpec(Class<T> paramSpec) 273 throws InvalidParameterSpecException 274 { 275 return paramSpi.engineGetParameterSpec(paramSpec); 276 } 277 278 /** 279 * Returns the parameters in the default encoding format. The primary encoding 280 * format is ASN.1 if it exists for the specified type. 281 * 282 * @return byte array representing the parameters. 283 */ 284 public final byte[] getEncoded() throws IOException 285 { 286 return paramSpi.engineGetEncoded(); 287 } 288 289 /** 290 * Returns the parameters in the specified encoding format. If 291 * <code>format</code> is <code>null</code> then the ASN.1 encoding 292 * format is used if it exists for the specified type. 293 * 294 * @param format 295 * the name of the encoding format to use. 296 * @return the parameters encoded using the specified encoding scheme. 297 * @throws IOException 298 * if an encoding exception occurs, or if this parameter object has 299 * not been initialized. 300 */ 301 public final byte[] getEncoded(String format) throws IOException 302 { 303 return paramSpi.engineGetEncoded(format); 304 } 305 306 /** 307 * Returns a string representation of the encoded form. 308 * 309 * @return a string representation of the encoded form. 310 */ 311 public final String toString() 312 { 313 return paramSpi.engineToString(); 314 } 315 }