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Diffstat (limited to 'libjava/classpath/gnu/javax/crypto/jce/params/DERWriter.java')
| -rw-r--r-- | libjava/classpath/gnu/javax/crypto/jce/params/DERWriter.java | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/libjava/classpath/gnu/javax/crypto/jce/params/DERWriter.java b/libjava/classpath/gnu/javax/crypto/jce/params/DERWriter.java new file mode 100644 index 00000000000..876c2cd6caa --- /dev/null +++ b/libjava/classpath/gnu/javax/crypto/jce/params/DERWriter.java @@ -0,0 +1,154 @@ +/* DERWriter.java -- + Copyright (C) 1999, 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.javax.crypto.jce.params; + +import java.math.BigInteger; + +class DERWriter +{ + static final int UNIVERSAL = 1; + + static final int APPLICATION = 2; + + static final int CONTEXT_SPECIFIC = 3; + + static final int PRIVATE = 4; + + public DERWriter() + { + } + + public byte[] writeBigInteger(BigInteger i) + { + return writePrimitive(0x02, UNIVERSAL, + (int) Math.ceil((double) i.bitLength() / 8), + i.toByteArray()); + } + + private byte[] writePrimitive(int identifier, int identifierencoding, + int length, byte contents[]) + { + return joinarrays(generateIdentifier(identifier, identifierencoding), + generateLength(length), contents); + } + + public byte[] joinarrays(byte a[], byte b[]) + { + byte d[] = new byte[a.length + b.length]; + System.arraycopy(a, 0, d, 0, a.length); + System.arraycopy(b, 0, d, a.length, b.length); + return d; + } + + public byte[] joinarrays(byte a[], byte b[], byte c[]) + { + byte d[] = new byte[a.length + b.length + c.length]; + System.arraycopy(a, 0, d, 0, a.length); + System.arraycopy(b, 0, d, a.length, b.length); + System.arraycopy(c, 0, d, a.length + b.length, c.length); + return d; + } + + private byte[] generateIdentifier(int identifier, int identifierencoding) + { + byte b[]; + if (identifier > 31) + { + int count = (int) (Math.log(identifier) / Math.log(256)); + b = new byte[count + 1]; + b[0] = (byte) (translateLeadIdentifierByte(identifierencoding) | 0x1f); + int i; + for (i = 1; i < (count + 1); i++) + { + b[i] = (byte) (0x7f & (identifier >> (7 * (count - i)))); + b[i] |= 0x80; + } + b[i - 1] ^= 0x80; + //System.out.println("Identifier1: " + b[0]); + return b; + } + else + { + b = new byte[1]; + b[0] = (byte) ((translateLeadIdentifierByte(identifierencoding) | (byte) (identifier & 0x1f)) & 0xdf); + //System.out.println("Identifier2: " + b[0]); + return b; + } + } + + private byte translateLeadIdentifierByte(int b) + { + if (b == UNIVERSAL) + return (byte) 0x3f; + else if (b == APPLICATION) + return (byte) 0x7f; + else if (b == CONTEXT_SPECIFIC) + return (byte) 0xbf; + else + return (byte) 0xC0; + } + + private byte[] generateLength(int length) + { + byte b[]; + if (length > 127) + { + int count = (int) Math.ceil(Math.log(length) / Math.log(256)); + //System.out.println("Length byte count: " + count); + b = new byte[count + 1]; + b[0] = (byte) ((count & 0x7f) | 0x80); + for (int i = 1; i < (count + 1); i++) + { + b[i] = (byte) (length >>> (8 * (count - i))); + //System.out.println("Length1 byte1: " + (length >>> (8 * ( count - i) ))); + //System.out.println("Length1 byte2: " + b[i]); + } + + //System.out.println("Length1: " + length); + return b; + } + else + { + b = new byte[1]; + b[0] = (byte) (length & 0x7f); + //System.out.println("Length2: " + length); + return b; + } + } +}
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