1 // Copyright 2000-2005 the Contributors, as shown in the revision logs.
2 // Licensed under the Apache Public Source License 2.0 ("the License").
3 // You may not use this file except in compliance with the License.
5 package org.ibex.crypto;
6 import java.math.BigInteger;
10 private final BigInteger pq;
11 private final BigInteger e;
12 private final boolean reverse;
14 public RSA(BigInteger pq, BigInteger e, boolean reverse) {
17 this.reverse = reverse;
20 public int getInputBlockSize() { return (pq.bitLength()+7) / 8 - (reverse ? 0 : 1); }
21 public int getOutputBlockSize() { return (pq.bitLength()+7) / 8 - (reverse ? 1 : 0); }
23 // FEATURE: Check that in.length is within the expected range
24 public byte[] process(byte[] in) {
25 // output block is the same size as the modulus (rounded up)
26 int outSize = getOutputBlockSize();
27 BigInteger t = new BigInteger(1,in);
28 BigInteger c = t.modPow(e,pq);
29 byte[] cbytes = c.toByteArray();
30 if(cbytes.length > outSize + 1) throw new RuntimeException("should never happen");
31 if(reverse ? cbytes[0] == 0 : cbytes.length > outSize) {
32 if(cbytes[0] != 0) throw new RuntimeException("should never happen");
33 byte[] buf = new byte[cbytes.length-1];
34 System.arraycopy(cbytes,1,buf,0,buf.length);
36 } else if(!reverse && cbytes.length < outSize) {
37 // output needs to be exactly outSize in length
38 byte[] buf = new byte[outSize];
39 System.arraycopy(cbytes,0,buf,outSize-cbytes.length,cbytes.length);
46 public static class PublicKey {
47 public final BigInteger modulus;
48 public final BigInteger exponent;
50 public PublicKey(Object o) {
51 Vector seq = (Vector) o;
52 modulus = (BigInteger) seq.elementAt(0);
53 exponent = (BigInteger) seq.elementAt(1);
57 public static class PrivateKey {
58 public final int version;
59 public final BigInteger modulus;
60 public final BigInteger publicExponent;
61 public final BigInteger privateExponent;
62 public final BigInteger prime1;
63 public final BigInteger prime2;
64 public final BigInteger exponent1;
65 public final BigInteger exponent2;
66 public final BigInteger coefficient;
68 public PrivateKey(Object o) throws DER.Exception {
69 Vector seq = (Vector) o;
70 version = ((Number)seq.elementAt(0)).intValue();
71 if(version != 0) throw new DER.Exception("Only private key version 0 is supported");
72 modulus = (BigInteger) seq.elementAt(1);
73 publicExponent = (BigInteger) seq.elementAt(2);
74 privateExponent = (BigInteger) seq.elementAt(3);
75 prime1 = (BigInteger) seq.elementAt(4);
76 prime2 = (BigInteger) seq.elementAt(5);
77 exponent1 = (BigInteger) seq.elementAt(6);
78 exponent2 = (BigInteger) seq.elementAt(7);
79 coefficient = (BigInteger) seq.elementAt(8);