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Diffstat (limited to 'libjava/classpath/gnu/java/security/util/Util.java')
| -rw-r--r-- | libjava/classpath/gnu/java/security/util/Util.java | 692 |
1 files changed, 692 insertions, 0 deletions
diff --git a/libjava/classpath/gnu/java/security/util/Util.java b/libjava/classpath/gnu/java/security/util/Util.java new file mode 100644 index 00000000000..53f8e3c2cca --- /dev/null +++ b/libjava/classpath/gnu/java/security/util/Util.java @@ -0,0 +1,692 @@ +/* Util.java -- various utility routines. + Copyright (C) 2001, 2002, 2003, 2006 Free Software Foundation, Inc. + +This file is a part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2 of the License, or (at +your option) any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; if not, write to the Free Software +Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 +USA + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package gnu.java.security.util; + +import java.math.BigInteger; + +/** + * <p>A collection of utility methods used throughout this project.</p> + * + * @version $Revision: 1.1 $ + */ +public class Util +{ + + // Constants and variables + // ------------------------------------------------------------------------- + + // Hex charset + private static final char[] HEX_DIGITS = "0123456789ABCDEF".toCharArray(); + + // Base-64 charset + private static final String BASE64_CHARS = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz./"; + + private static final char[] BASE64_CHARSET = BASE64_CHARS.toCharArray(); + + // Constructor(s) + // ------------------------------------------------------------------------- + + /** Trivial constructor to enforce Singleton pattern. */ + private Util() + { + super(); + } + + // Class methods + // ------------------------------------------------------------------------- + + /** + * <p>Returns a string of hexadecimal digits from a byte array. Each byte is + * converted to 2 hex symbols; zero(es) included.</p> + * + * <p>This method calls the method with same name and three arguments as:</p> + * + * <pre> + * toString(ba, 0, ba.length); + * </pre> + * + * @param ba the byte array to convert. + * @return a string of hexadecimal characters (two for each byte) + * representing the designated input byte array. + */ + public static String toString(byte[] ba) + { + return toString(ba, 0, ba.length); + } + + /** + * <p>Returns a string of hexadecimal digits from a byte array, starting at + * <code>offset</code> and consisting of <code>length</code> bytes. Each byte + * is converted to 2 hex symbols; zero(es) included.</p> + * + * @param ba the byte array to convert. + * @param offset the index from which to start considering the bytes to + * convert. + * @param length the count of bytes, starting from the designated offset to + * convert. + * @return a string of hexadecimal characters (two for each byte) + * representing the designated input byte sub-array. + */ + public static final String toString(byte[] ba, int offset, int length) + { + char[] buf = new char[length * 2]; + for (int i = 0, j = 0, k; i < length;) + { + k = ba[offset + i++]; + buf[j++] = HEX_DIGITS[(k >>> 4) & 0x0F]; + buf[j++] = HEX_DIGITS[k & 0x0F]; + } + return new String(buf); + } + + /** + * <p>Returns a string of hexadecimal digits from a byte array. Each byte is + * converted to 2 hex symbols; zero(es) included. The argument is + * treated as a large little-endian integer and is returned as a + * large big-endian integer.</p> + * + * <p>This method calls the method with same name and three arguments as:</p> + * + * <pre> + * toReversedString(ba, 0, ba.length); + * </pre> + * + * @param ba the byte array to convert. + * @return a string of hexadecimal characters (two for each byte) + * representing the designated input byte array. + */ + public static String toReversedString(byte[] ba) + { + return toReversedString(ba, 0, ba.length); + } + + /** + * <p>Returns a string of hexadecimal digits from a byte array, starting at + * <code>offset</code> and consisting of <code>length</code> bytes. Each byte + * is converted to 2 hex symbols; zero(es) included.</p> + * + * <p>The byte array is treated as a large little-endian integer, and + * is returned as a large big-endian integer.</p> + * + * @param ba the byte array to convert. + * @param offset the index from which to start considering the bytes to + * convert. + * @param length the count of bytes, starting from the designated offset to + * convert. + * @return a string of hexadecimal characters (two for each byte) + * representing the designated input byte sub-array. + */ + public static final String toReversedString(byte[] ba, int offset, int length) + { + char[] buf = new char[length * 2]; + for (int i = offset + length - 1, j = 0, k; i >= offset;) + { + k = ba[offset + i--]; + buf[j++] = HEX_DIGITS[(k >>> 4) & 0x0F]; + buf[j++] = HEX_DIGITS[k & 0x0F]; + } + return new String(buf); + } + + /** + * <p>Returns a byte array from a string of hexadecimal digits.</p> + * + * @param s a string of hexadecimal ASCII characters + * @return the decoded byte array from the input hexadecimal string. + */ + public static byte[] toBytesFromString(String s) + { + int limit = s.length(); + byte[] result = new byte[((limit + 1) / 2)]; + int i = 0, j = 0; + if ((limit % 2) == 1) + { + result[j++] = (byte) fromDigit(s.charAt(i++)); + } + while (i < limit) + { + result[j] = (byte) (fromDigit(s.charAt(i++)) << 4); + result[j++] |= (byte) fromDigit(s.charAt(i++)); + } + return result; + } + + /** + * <p>Returns a byte array from a string of hexadecimal digits, interpreting + * them as a large big-endian integer and returning it as a large + * little-endian integer.</p> + * + * @param s a string of hexadecimal ASCII characters + * @return the decoded byte array from the input hexadecimal string. + */ + public static byte[] toReversedBytesFromString(String s) + { + int limit = s.length(); + byte[] result = new byte[((limit + 1) / 2)]; + int i = 0; + if ((limit % 2) == 1) + { + result[i++] = (byte) fromDigit(s.charAt(--limit)); + } + while (limit > 0) + { + result[i] = (byte) fromDigit(s.charAt(--limit)); + result[i++] |= (byte) (fromDigit(s.charAt(--limit)) << 4); + } + return result; + } + + /** + * <p>Returns a number from <code>0</code> to <code>15</code> corresponding + * to the designated hexadecimal digit.</p> + * + * @param c a hexadecimal ASCII symbol. + */ + public static int fromDigit(char c) + { + if (c >= '0' && c <= '9') + { + return c - '0'; + } + else if (c >= 'A' && c <= 'F') + { + return c - 'A' + 10; + } + else if (c >= 'a' && c <= 'f') + { + return c - 'a' + 10; + } + else + throw new IllegalArgumentException("Invalid hexadecimal digit: " + c); + } + + /** + * <p>Returns a string of 8 hexadecimal digits (most significant digit first) + * corresponding to the unsigned integer <code>n</code>.</p> + * + * @param n the unsigned integer to convert. + * @return a hexadecimal string 8-character long. + */ + public static String toString(int n) + { + char[] buf = new char[8]; + for (int i = 7; i >= 0; i--) + { + buf[i] = HEX_DIGITS[n & 0x0F]; + n >>>= 4; + } + return new String(buf); + } + + /** + * <p>Returns a string of hexadecimal digits from an integer array. Each int + * is converted to 4 hex symbols.</p> + */ + public static String toString(int[] ia) + { + int length = ia.length; + char[] buf = new char[length * 8]; + for (int i = 0, j = 0, k; i < length; i++) + { + k = ia[i]; + buf[j++] = HEX_DIGITS[(k >>> 28) & 0x0F]; + buf[j++] = HEX_DIGITS[(k >>> 24) & 0x0F]; + buf[j++] = HEX_DIGITS[(k >>> 20) & 0x0F]; + buf[j++] = HEX_DIGITS[(k >>> 16) & 0x0F]; + buf[j++] = HEX_DIGITS[(k >>> 12) & 0x0F]; + buf[j++] = HEX_DIGITS[(k >>> 8) & 0x0F]; + buf[j++] = HEX_DIGITS[(k >>> 4) & 0x0F]; + buf[j++] = HEX_DIGITS[k & 0x0F]; + } + return new String(buf); + } + + /** + * <p>Returns a string of 16 hexadecimal digits (most significant digit first) + * corresponding to the unsigned long <code>n</code>.</p> + * + * @param n the unsigned long to convert. + * @return a hexadecimal string 16-character long. + */ + public static String toString(long n) + { + char[] b = new char[16]; + for (int i = 15; i >= 0; i--) + { + b[i] = HEX_DIGITS[(int) (n & 0x0FL)]; + n >>>= 4; + } + return new String(b); + } + + /** + * <p>Similar to the <code>toString()</code> method except that the Unicode + * escape character is inserted before every pair of bytes. Useful to + * externalise byte arrays that will be constructed later from such strings; + * eg. s-box values.</p> + * + * @throws ArrayIndexOutOfBoundsException if the length is odd. + */ + public static String toUnicodeString(byte[] ba) + { + return toUnicodeString(ba, 0, ba.length); + } + + /** + * <p>Similar to the <code>toString()</code> method except that the Unicode + * escape character is inserted before every pair of bytes. Useful to + * externalise byte arrays that will be constructed later from such strings; + * eg. s-box values.</p> + * + * @throws ArrayIndexOutOfBoundsException if the length is odd. + */ + public static final String toUnicodeString(byte[] ba, int offset, int length) + { + StringBuffer sb = new StringBuffer(); + int i = 0; + int j = 0; + int k; + sb.append('\n').append("\""); + while (i < length) + { + sb.append("\\u"); + + k = ba[offset + i++]; + sb.append(HEX_DIGITS[(k >>> 4) & 0x0F]); + sb.append(HEX_DIGITS[k & 0x0F]); + + k = ba[offset + i++]; + sb.append(HEX_DIGITS[(k >>> 4) & 0x0F]); + sb.append(HEX_DIGITS[k & 0x0F]); + + if ((++j % 8) == 0) + { + sb.append("\"+").append('\n').append("\""); + } + } + sb.append("\"").append('\n'); + return sb.toString(); + } + + /** + * <p>Similar to the <code>toString()</code> method except that the Unicode + * escape character is inserted before every pair of bytes. Useful to + * externalise integer arrays that will be constructed later from such + * strings; eg. s-box values.</p> + * + * @throws ArrayIndexOutOfBoundsException if the length is not a multiple of 4. + */ + public static String toUnicodeString(int[] ia) + { + StringBuffer sb = new StringBuffer(); + int i = 0; + int j = 0; + int k; + sb.append('\n').append("\""); + while (i < ia.length) + { + k = ia[i++]; + sb.append("\\u"); + sb.append(HEX_DIGITS[(k >>> 28) & 0x0F]); + sb.append(HEX_DIGITS[(k >>> 24) & 0x0F]); + sb.append(HEX_DIGITS[(k >>> 20) & 0x0F]); + sb.append(HEX_DIGITS[(k >>> 16) & 0x0F]); + sb.append("\\u"); + sb.append(HEX_DIGITS[(k >>> 12) & 0x0F]); + sb.append(HEX_DIGITS[(k >>> 8) & 0x0F]); + sb.append(HEX_DIGITS[(k >>> 4) & 0x0F]); + sb.append(HEX_DIGITS[k & 0x0F]); + + if ((++j % 4) == 0) + { + sb.append("\"+").append('\n').append("\""); + } + } + sb.append("\"").append('\n'); + return sb.toString(); + } + + public static byte[] toBytesFromUnicode(String s) + { + int limit = s.length() * 2; + byte[] result = new byte[limit]; + char c; + for (int i = 0; i < limit; i++) + { + c = s.charAt(i >>> 1); + result[i] = (byte) (((i & 1) == 0) ? c >>> 8 : c); + } + return result; + } + + /** + * <p>Dumps a byte array as a string, in a format that is easy to read for + * debugging. The string <code>m</code> is prepended to the start of each + * line.</p> + * + * <p>If <code>offset</code> and <code>length</code> are omitted, the whole + * array is used. If <code>m</code> is omitted, nothing is prepended to each + * line.</p> + * + * @param data the byte array to be dumped. + * @param offset the offset within <i>data</i> to start from. + * @param length the number of bytes to dump. + * @param m a string to be prepended to each line. + * @return a string containing the result. + */ + public static String dumpString(byte[] data, int offset, int length, String m) + { + if (data == null) + { + return m + "null\n"; + } + StringBuffer sb = new StringBuffer(length * 3); + if (length > 32) + { + sb.append(m).append("Hexadecimal dump of ").append(length).append( + " bytes...\n"); + } + // each line will list 32 bytes in 4 groups of 8 each + int end = offset + length; + String s; + int l = Integer.toString(length).length(); + if (l < 4) + { + l = 4; + } + for (; offset < end; offset += 32) + { + if (length > 32) + { + s = " " + offset; + sb.append(m).append(s.substring(s.length() - l)).append(": "); + } + int i = 0; + for (; i < 32 && offset + i + 7 < end; i += 8) + { + sb.append(toString(data, offset + i, 8)).append(' '); + } + if (i < 32) + { + for (; i < 32 && offset + i < end; i++) + { + sb.append(byteToString(data[offset + i])); + } + } + sb.append('\n'); + } + return sb.toString(); + } + + public static String dumpString(byte[] data) + { + return (data == null) ? "null\n" : dumpString(data, 0, data.length, ""); + } + + public static String dumpString(byte[] data, String m) + { + return (data == null) ? "null\n" : dumpString(data, 0, data.length, m); + } + + public static String dumpString(byte[] data, int offset, int length) + { + return dumpString(data, offset, length, ""); + } + + /** + * <p>Returns a string of 2 hexadecimal digits (most significant digit first) + * corresponding to the lowest 8 bits of <code>n</code>.</p> + * + * @param n the byte value to convert. + * @return a string of 2 hex characters representing the input. + */ + public static String byteToString(int n) + { + char[] buf = { HEX_DIGITS[(n >>> 4) & 0x0F], HEX_DIGITS[n & 0x0F] }; + return new String(buf); + } + + /** + * <p>Converts a designated byte array to a Base-64 representation, with the + * exceptions that (a) leading 0-byte(s) are ignored, and (b) the character + * '.' (dot) shall be used instead of "+' (plus).</p> + * + * <p>Used by SASL password file manipulation primitives.</p> + * + * @param buffer an arbitrary sequence of bytes to represent in Base-64. + * @return unpadded (without the '=' character(s)) Base-64 representation of + * the input. + */ + public static final String toBase64(byte[] buffer) + { + int len = buffer.length, pos = len % 3; + byte b0 = 0, b1 = 0, b2 = 0; + switch (pos) + { + case 1: + b2 = buffer[0]; + break; + case 2: + b1 = buffer[0]; + b2 = buffer[1]; + break; + } + StringBuffer sb = new StringBuffer(); + int c; + boolean notleading = false; + do + { + c = (b0 & 0xFC) >>> 2; + if (notleading || c != 0) + { + sb.append(BASE64_CHARSET[c]); + notleading = true; + } + c = ((b0 & 0x03) << 4) | ((b1 & 0xF0) >>> 4); + if (notleading || c != 0) + { + sb.append(BASE64_CHARSET[c]); + notleading = true; + } + c = ((b1 & 0x0F) << 2) | ((b2 & 0xC0) >>> 6); + if (notleading || c != 0) + { + sb.append(BASE64_CHARSET[c]); + notleading = true; + } + c = b2 & 0x3F; + if (notleading || c != 0) + { + sb.append(BASE64_CHARSET[c]); + notleading = true; + } + if (pos >= len) + { + break; + } + else + { + try + { + b0 = buffer[pos++]; + b1 = buffer[pos++]; + b2 = buffer[pos++]; + } + catch (ArrayIndexOutOfBoundsException x) + { + break; + } + } + } + while (true); + + if (notleading) + { + return sb.toString(); + } + return "0"; + } + + /** + * <p>The inverse function of the above.</p> + * + * <p>Converts a string representing the encoding of some bytes in Base-64 + * to their original form.</p> + * + * @param str the Base-64 encoded representation of some byte(s). + * @return the bytes represented by the <code>str</code>. + * @throws NumberFormatException if <code>str</code> is <code>null</code>, or + * <code>str</code> contains an illegal Base-64 character. + * @see #toBase64(byte[]) + */ + public static final byte[] fromBase64(String str) + { + int len = str.length(); + if (len == 0) + { + throw new NumberFormatException("Empty string"); + } + byte[] a = new byte[len + 1]; + int i, j; + for (i = 0; i < len; i++) + { + try + { + a[i] = (byte) BASE64_CHARS.indexOf(str.charAt(i)); + } + catch (ArrayIndexOutOfBoundsException x) + { + throw new NumberFormatException("Illegal character at #" + i); + } + } + i = len - 1; + j = len; + try + { + while (true) + { + a[j] = a[i]; + if (--i < 0) + { + break; + } + a[j] |= (a[i] & 0x03) << 6; + j--; + a[j] = (byte) ((a[i] & 0x3C) >>> 2); + if (--i < 0) + { + break; + } + a[j] |= (a[i] & 0x0F) << 4; + j--; + a[j] = (byte) ((a[i] & 0x30) >>> 4); + if (--i < 0) + { + break; + } + a[j] |= (a[i] << 2); + j--; + a[j] = 0; + if (--i < 0) + { + break; + } + } + } + catch (Exception ignored) + { + } + + try + { // ignore leading 0-bytes + while (a[j] == 0) + { + j++; + } + } + catch (Exception x) + { + return new byte[1]; // one 0-byte + } + byte[] result = new byte[len - j + 1]; + System.arraycopy(a, j, result, 0, len - j + 1); + return result; + } + + // BigInteger utilities ---------------------------------------------------- + + /** + * <p>Treats the input as the MSB representation of a number, and discards + * leading zero elements. For efficiency, the input is simply returned if no + * leading zeroes are found.</p> + * + * @param n the {@link BigInteger} to trim. + * @return the byte array representation of the designated {@link BigInteger} + * with no leading 0-bytes. + */ + public static final byte[] trim(BigInteger n) + { + byte[] in = n.toByteArray(); + if (in.length == 0 || in[0] != 0) + { + return in; + } + int len = in.length; + int i = 1; + while (in[i] == 0 && i < len) + { + ++i; + } + byte[] result = new byte[len - i]; + System.arraycopy(in, i, result, 0, len - i); + return result; + } + + /** + * <p>Returns a hexadecimal dump of the trimmed bytes of a {@link BigInteger}. + * </p> + * + * @param x the {@link BigInteger} to display. + * @return the string representation of the designated {@link BigInteger}. + */ + public static final String dump(BigInteger x) + { + return dumpString(trim(x)); + } +} |