| |
| package com.trilead.ssh2.crypto.dh; |
| |
| import com.trilead.ssh2.crypto.digest.HashForSSH2Types; |
| import com.trilead.ssh2.log.Logger; |
| |
| import java.io.UnsupportedEncodingException; |
| import java.math.BigInteger; |
| import java.security.SecureRandom; |
| |
| |
| /** |
| * DhExchange. |
| * |
| * @author Christian Plattner, plattner@trilead.com |
| * @version $Id: DhExchange.java,v 1.2 2008/04/01 12:38:09 cplattne Exp $ |
| */ |
| public class DhExchange |
| { |
| private static final Logger log = Logger.getLogger(DhExchange.class); |
| |
| /* Given by the standard */ |
| |
| static final BigInteger p1, p14; |
| static final BigInteger g; |
| |
| BigInteger p; |
| |
| /* Client public and private */ |
| |
| BigInteger e; |
| BigInteger x; |
| |
| /* Server public */ |
| |
| BigInteger f; |
| |
| /* Shared secret */ |
| |
| BigInteger k; |
| |
| static |
| { |
| final String p1_string = "17976931348623159077083915679378745319786029604875" |
| + "60117064444236841971802161585193689478337958649255415021805654859805036464" |
| + "40548199239100050792877003355816639229553136239076508735759914822574862575" |
| + "00742530207744771258955095793777842444242661733472762929938766870920560605" |
| + "0270810842907692932019128194467627007"; |
| |
| final String p14_string = "FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129" |
| + "024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0" |
| + "A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB" |
| + "6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3DC2007CB8A" |
| + "163BF0598DA48361C55D39A69163FA8FD24CF5F83655D23DCA3AD961C62F356208" |
| + "552BB9ED529077096966D670C354E4ABC9804F1746C08CA18217C32905E462E36C" |
| + "E3BE39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9DE2BCBF69558171" |
| + "83995497CEA956AE515D2261898FA051015728E5A8AACAA68FFFFFFFFFFFFFFFF"; |
| |
| p1 = new BigInteger(p1_string); |
| p14 = new BigInteger(p14_string, 16); |
| g = new BigInteger("2"); |
| } |
| |
| public DhExchange() |
| { |
| } |
| |
| public void init(int group, SecureRandom rnd) |
| { |
| k = null; |
| |
| if (group == 1) |
| p = p1; |
| else if (group == 14) |
| p = p14; |
| else |
| throw new IllegalArgumentException("Unknown DH group " + group); |
| |
| x = new BigInteger(p.bitLength() - 1, rnd); |
| |
| e = g.modPow(x, p); |
| } |
| |
| /** |
| * @return Returns the e. |
| * @throws IllegalStateException |
| */ |
| public BigInteger getE() |
| { |
| if (e == null) |
| throw new IllegalStateException("DhDsaExchange not initialized!"); |
| |
| return e; |
| } |
| |
| /** |
| * @return Returns the shared secret k. |
| * @throws IllegalStateException |
| */ |
| public BigInteger getK() |
| { |
| if (k == null) |
| throw new IllegalStateException("Shared secret not yet known, need f first!"); |
| |
| return k; |
| } |
| |
| /** |
| * @param f |
| */ |
| public void setF(BigInteger f) |
| { |
| if (e == null) |
| throw new IllegalStateException("DhDsaExchange not initialized!"); |
| |
| BigInteger zero = BigInteger.valueOf(0); |
| |
| if (zero.compareTo(f) >= 0 || p.compareTo(f) <= 0) |
| throw new IllegalArgumentException("Invalid f specified!"); |
| |
| this.f = f; |
| this.k = f.modPow(x, p); |
| } |
| |
| public byte[] calculateH(byte[] clientversion, byte[] serverversion, byte[] clientKexPayload, |
| byte[] serverKexPayload, byte[] hostKey) throws UnsupportedEncodingException |
| { |
| HashForSSH2Types hash = new HashForSSH2Types("SHA1"); |
| |
| if (log.isEnabled()) |
| { |
| log.log(90, "Client: '" + new String(clientversion, "ISO-8859-1") + "'"); |
| log.log(90, "Server: '" + new String(serverversion, "ISO-8859-1") + "'"); |
| } |
| |
| hash.updateByteString(clientversion); |
| hash.updateByteString(serverversion); |
| hash.updateByteString(clientKexPayload); |
| hash.updateByteString(serverKexPayload); |
| hash.updateByteString(hostKey); |
| hash.updateBigInt(e); |
| hash.updateBigInt(f); |
| hash.updateBigInt(k); |
| |
| return hash.getDigest(); |
| } |
| } |