libjava/classpath/gnu/javax/net/ssl/provider/Util.java

   1 /* Util.java -- Miscellaneous utility methods.
   2    Copyright (C) 2006  Free Software Foundation, Inc.
   3
   4 This file is a 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 of the License, or (at
   9 your option) 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; if not, write to the Free Software
  18 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
  19 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 gnu.javax.net.ssl.provider;
  40
  41 import java.lang.reflect.Array;
  42 import java.lang.reflect.InvocationTargetException;
  43 import java.lang.reflect.Method;
  44 import java.math.BigInteger;
  45
  46 import java.security.AccessController;
  47 import java.security.PrivilegedAction;
  48 import java.security.Security;
  49
  50 /**
  51  * A collection of useful class methods.
  52  *
  53  * @author Casey Marshall (rsdio@metastatic.org)
  54  */
  55 final class Util
  56 {
  57
  58   // Constants.
  59   // -------------------------------------------------------------------------
  60
  61   static final String HEX = "0123456789abcdef";
  62
  63   // Static methods only.
  64   private Util() { }
  65
  66   // Class methods.
  67   // -------------------------------------------------------------------------
  68
  69   /**
  70    * Convert a hexadecimal string into its byte representation.
  71    *
  72    * @param hex The hexadecimal string.
  73    * @return The converted bytes.
  74    */
  75   static byte[] toByteArray(String hex)
  76   {
  77     hex = hex.toLowerCase();
  78     byte[] buf = new byte[hex.length() / 2];
  79     int j = 0;
  80     for (int i = 0; i < buf.length; i++)
  81       {
  82         buf[i] = (byte) ((Character.digit(hex.charAt(j++), 16) << 4) |
  83                           Character.digit(hex.charAt(j++), 16));
  84       }
  85     return buf;
  86   }
  87
  88   /**
  89    * Convert a byte array to a hexadecimal string, as though it were a
  90    * big-endian arbitrarily-sized integer.
  91    *
  92    * @param buf The bytes to format.
  93    * @param off The offset to start at.
  94    * @param len The number of bytes to format.
  95    * @return A hexadecimal representation of the specified bytes.
  96    */
  97   static String toHexString(byte[] buf, int off, int len)
  98   {
  99     StringBuffer str = new StringBuffer();
 100     for (int i = 0; i < len; i++)
 101       {
 102         str.append(HEX.charAt(buf[i+off] >>> 4 & 0x0F));
 103         str.append(HEX.charAt(buf[i+off] & 0x0F));
 104       }
 105     return str.toString();
 106   }
 107
 108   /**
 109    * See {@link #toHexString(byte[],int,int)}.
 110    */
 111   static String toHexString(byte[] buf)
 112   {
 113     return Util.toHexString(buf, 0, buf.length);
 114   }
 115
 116   /**
 117    * Convert a byte array to a hexadecimal string, separating octets
 118    * with the given character.
 119    *
 120    * @param buf The bytes to format.
 121    * @param off The offset to start at.
 122    * @param len The number of bytes to format.
 123    * @param sep The character to insert between octets.
 124    * @return A hexadecimal representation of the specified bytes.
 125    */
 126   static String toHexString(byte[] buf, int off, int len, char sep)
 127   {
 128     StringBuffer str = new StringBuffer();
 129     for (int i = 0; i < len; i++)
 130       {
 131         str.append(HEX.charAt(buf[i+off] >>> 4 & 0x0F));
 132         str.append(HEX.charAt(buf[i+off] & 0x0F));
 133         if (i < len - 1)
 134           str.append(sep);
 135       }
 136     return str.toString();
 137   }
 138
 139   /**
 140    * See {@link #toHexString(byte[],int,int,char)}.
 141    */
 142   static String toHexString(byte[] buf, char sep)
 143   {
 144     return Util.toHexString(buf, 0, buf.length, sep);
 145   }
 146
 147   /**
 148    * Create a representation of the given byte array similar to the
 149    * output of <code>`hexdump -C'</code>, which is
 150    *
 151    * <p><pre>OFFSET  SIXTEEN-BYTES-IN-HEX  PRINTABLE-BYTES</pre>
 152    *
 153    * <p>The printable bytes show up as-is if they are printable and
 154    * not a newline character, otherwise showing as '.'.
 155    *
 156    * @param buf The bytes to format.
 157    * @param off The offset to start at.
 158    * @param len The number of bytes to encode.
 159    * @param prefix A string to prepend to every line.
 160    * @return The formatted string.
 161    */
 162   static String hexDump(byte[] buf, int off, int len, String prefix)
 163   {
 164     String nl = getProperty("line.separator");
 165     StringBuffer str = new StringBuffer();
 166     int i = 0;
 167     while (i < len)
 168       {
 169         if (prefix != null)
 170           str.append(prefix);
 171         str.append(Util.formatInt(i+off, 16, 8));
 172         str.append("  ");
 173         String s = Util.toHexString(buf, i+off, Math.min(16, len-i), ' ');
 174         str.append(s);
 175         for (int j = 56 - (56 - s.length()); j < 56; j++)
 176           str.append(" ");
 177         for (int j = 0; j < Math.min(16, len - i); j++)
 178           {
 179             if ((buf[i+off+j] & 0xFF) < 0x20 || (buf[i+off+j] & 0xFF) > 0x7E)
 180               str.append('.');
 181             else
 182               str.append((char) (buf[i+off+j] & 0xFF));
 183           }
 184         str.append(nl);
 185         i += 16;
 186       }
 187     return str.toString();
 188   }
 189
 190   /**
 191    * See {@link #hexDump(byte[],int,int,String)}.
 192    */
 193   static String hexDump(byte[] buf, int off, int len)
 194   {
 195     return hexDump(buf, off, len, "");
 196   }
 197
 198   /**
 199    * See {@link #hexDump(byte[],int,int,String)}.
 200    */
 201   static String hexDump(byte[] buf, String prefix)
 202   {
 203     return hexDump(buf, 0, buf.length, prefix);
 204   }
 205
 206   /**
 207    * See {@link #hexDump(byte[],int,int,String)}.
 208    */
 209   static String hexDump(byte[] buf)
 210   {
 211     return hexDump(buf, 0, buf.length);
 212   }
 213
 214   /**
 215    * Format an integer into the specified radix, zero-filled.
 216    *
 217    * @param i The integer to format.
 218    * @param radix The radix to encode to.
 219    * @param len The target length of the string. The string is
 220    *   zero-padded to this length, but may be longer.
 221    * @return The formatted integer.
 222    */
 223   static String formatInt(int i, int radix, int len)
 224   {
 225     String s = Integer.toString(i, radix);
 226     StringBuffer buf = new StringBuffer();
 227     for (int j = 0; j < len - s.length(); j++)
 228       buf.append("0");
 229     buf.append(s);
 230     return buf.toString();
 231   }
 232
 233   /**
 234    * Concatenate two byte arrays into one.
 235    *
 236    * @param b1 The first byte array.
 237    * @param b2 The second byte array.
 238    * @return The concatenation of b1 and b2.
 239    */
 240   static byte[] concat(byte[] b1, byte[] b2)
 241   {
 242     byte[] b3 = new byte[b1.length+b2.length];
 243     System.arraycopy(b1, 0, b3, 0, b1.length);
 244     System.arraycopy(b2, 0, b3, b1.length, b2.length);
 245     return b3;
 246   }
 247
 248   /**
 249    * See {@link #trim(byte[],int,int)}.
 250    */
 251   static byte[] trim(byte[] buffer, int len)
 252   {
 253     return trim(buffer, 0, len);
 254   }
 255
 256   /**
 257    * Returns a portion of a byte array, possibly zero-filled.
 258    *
 259    * @param buffer The byte array to trim.
 260    * @param off The offset to begin reading at.
 261    * @param len The number of bytes to return. This value can be larger
 262    *        than <i>buffer.length - off</i>, in which case the rest of the
 263    *        returned byte array will be filled with zeros.
 264    * @throws IndexOutOfBoundsException If <i>off</i> or <i>len</i> is
 265    *         negative, or if <i>off</i> is larger than the byte array's
 266    *         length.
 267    * @return The trimmed byte array.
 268    */
 269   static byte[] trim(byte[] buffer, int off, int len)
 270   {
 271     if (off < 0 || len < 0 || off > buffer.length)
 272       throw new IndexOutOfBoundsException("max=" + buffer.length +
 273                                           " off=" + off + " len=" + len);
 274     if (off == 0 && len == buffer.length)
 275       return buffer;
 276     byte[] b = new byte[len];
 277     System.arraycopy(buffer, off, b, 0, Math.min(len, buffer.length - off));
 278     return b;
 279   }
 280
 281   /**
 282    * Returns the byte array representation of the given big integer with
 283    * the leading zero byte (if any) trimmed off.
 284    *
 285    * @param bi The integer to trim.
 286    * @return The byte representation of the big integer, with any leading
 287    *   zero removed.
 288    */
 289   static byte[] trim(BigInteger bi)
 290   {
 291     byte[] buf = bi.toByteArray();
 292     if (buf[0] == 0x00 && !bi.equals(BigInteger.ZERO))
 293       {
 294         return trim(buf, 1, buf.length - 1);
 295       }
 296     else
 297       {
 298         return buf;
 299       }
 300   }
 301
 302   /**
 303    * Returns the integer value of <code>{@link
 304    * java.lang.System#currentTimeMillis()} / 1000</code>.
 305    *
 306    * @return The current time, in seconds.
 307    */
 308   static int unixTime()
 309   {
 310     return (int) (System.currentTimeMillis() / 1000L);
 311   }
 312
 313   /**
 314    * Transform an Object array into another by calling the given method
 315    * on each object. The returned object array will have the runtime
 316    * type of <i>returnType</i>. For example, the following will transform
 317    * array of objects into their String representations, returning a String
 318    * array. For example:
 319    *
 320    * <blockquote><p><code>
 321    * String[] strings = (String[]) Util.transform(array, String.class,
 322    * "toString", null);
 323    * </code></p></blockquote>
 324    *
 325    * <p>If any element of the given array is <tt>null</tt>, then that
 326    * entry in the returned array will also be <tt>null</tt>.
 327    *
 328    * @param array The array to transform. It does not need to be of
 329    *        uniform type.
 330    * @param returnType The desired return type of the returned array.
 331    *        This must by the <i>component</i> type, not the array type.
 332    * @param method The name of the method to invoke from each object.
 333    * @param args The arguments to pass to the method, or <tt>null</tt>
 334    *        if the method takes no arguments.
 335    * @throws InvocationTargetException If an exception occurs while
 336    *         calling <i>method</i> of any object.
 337    * @throws NoSuchMethodException If <i>method</i> is not the name of
 338    *         a valid method of any component of the array.
 339    * @throws ClassCastException If the returned object from the method
 340    *         is not assignable to the return type.
 341    * @throws IllegalArgumentException If <i>args</i> is not appropriate
 342    *         for <i>method</i>
 343    * @throws IllegalAccessException If <i>method</i> is not accessible.
 344    * @throws SecurityException If <i>method</i> is not accessible.
 345    * @return An array containing the output of <i>method</i> called on
 346    *         each element of <i>array</i> with <i>args</i>. The return type
 347    *         of the array will be an array of <i>returnType</i>.
 348    */
 349   static Object[] transform(Object[] array, Class returnType,
 350                             String method, Object[] args)
 351     throws InvocationTargetException, NoSuchMethodException,
 352            IllegalAccessException
 353   {
 354     if (args == null)
 355       args = new Object[0];
 356     Object[] result = (Object[]) Array.newInstance(returnType, array.length);
 357     Class[] argsClasses = new Class[args.length];
 358     for (int i = 0; i < args.length; i++)
 359       {
 360         argsClasses[i] = args[i].getClass();
 361       }
 362     for (int i = 0; i < array.length; i++)
 363       {
 364         if (array[i] == null)
 365           {
 366             result[i] = null;
 367             continue;
 368           }
 369         Class objClass = array[i].getClass();
 370         Method objMethod = objClass.getMethod(method, argsClasses);
 371         Object o = objMethod.invoke(array[i], args);
 372         if (!returnType.isAssignableFrom(o.getClass()))
 373           throw new ClassCastException();
 374         result[i] = o;
 375       }
 376     return result;
 377   }
 378
 379   /**
 380    * Get a system property as a privileged action.
 381    *
 382    * @param name The name of the property to get.
 383    * @return The property named <i>name</i>, or null if the property is
 384    *   not set.
 385    * @throws SecurityException If the Jessie code still does not have
 386    *   permission to read the property.
 387    */
 388   static String getProperty(final String name)
 389   {
 390     return (String) AccessController.doPrivileged(
 391       new PrivilegedAction()
 392       {
 393         public Object run()
 394         {
 395           return System.getProperty(name);
 396         }
 397       }
 398     );
 399   }
 400
 401   /**
 402    * Get a security property as a privileged action.
 403    *
 404    * @param name The name of the property to get.
 405    * @return The property named <i>name</i>, or null if the property is
 406    *   not set.
 407    * @throws SecurityException If the Jessie code still does not have
 408    *   permission to read the property.
 409    */
 410   static String getSecurityProperty(final String name)
 411   {
 412     return (String) AccessController.doPrivileged(
 413       new PrivilegedAction()
 414       {
 415         public Object run()
 416         {
 417           return Security.getProperty(name);
 418         }
 419       }
 420     );
 421   }
 422 }