diff options
Diffstat (limited to 'lib/src/main/java/com/trilead/ssh2/signature/DSASHA1Verify.java')
| -rw-r--r-- | lib/src/main/java/com/trilead/ssh2/signature/DSASHA1Verify.java | 235 |
1 files changed, 140 insertions, 95 deletions
diff --git a/lib/src/main/java/com/trilead/ssh2/signature/DSASHA1Verify.java b/lib/src/main/java/com/trilead/ssh2/signature/DSASHA1Verify.java index c838ebd..357d66e 100644 --- a/lib/src/main/java/com/trilead/ssh2/signature/DSASHA1Verify.java +++ b/lib/src/main/java/com/trilead/ssh2/signature/DSASHA1Verify.java @@ -3,9 +3,19 @@ package com.trilead.ssh2.signature; import java.io.IOException;
import java.math.BigInteger;
+import java.security.InvalidKeyException;
+import java.security.KeyFactory;
+import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
+import java.security.Signature;
+import java.security.SignatureException;
+import java.security.interfaces.DSAParams;
+import java.security.interfaces.DSAPrivateKey;
+import java.security.interfaces.DSAPublicKey;
+import java.security.spec.DSAPublicKeySpec;
+import java.security.spec.InvalidKeySpecException;
+import java.security.spec.KeySpec;
-import com.trilead.ssh2.crypto.digest.SHA1;
import com.trilead.ssh2.log.Logger;
import com.trilead.ssh2.packets.TypesReader;
import com.trilead.ssh2.packets.TypesWriter;
@@ -38,7 +48,20 @@ public class DSASHA1Verify if (tr.remain() != 0)
throw new IOException("Padding in DSA public key!");
- return new DSAPublicKey(p, q, g, y);
+ try {
+ KeyFactory kf = KeyFactory.getInstance("DSA");
+
+ KeySpec ks = new DSAPublicKeySpec(y, p, q, g);
+ return (DSAPublicKey) kf.generatePublic(ks);
+ } catch (NoSuchAlgorithmException e) {
+ IOException ex = new IOException();
+ ex.initCause(e);
+ throw ex;
+ } catch (InvalidKeySpecException e) {
+ IOException ex = new IOException();
+ ex.initCause(e);
+ throw ex;
+ }
}
public static byte[] encodeSSHDSAPublicKey(DSAPublicKey pk) throws IOException
@@ -46,25 +69,47 @@ public class DSASHA1Verify TypesWriter tw = new TypesWriter();
tw.writeString("ssh-dss");
- tw.writeMPInt(pk.getP());
- tw.writeMPInt(pk.getQ());
- tw.writeMPInt(pk.getG());
+
+ DSAParams params = pk.getParams();
+ tw.writeMPInt(params.getP());
+ tw.writeMPInt(params.getQ());
+ tw.writeMPInt(params.getG());
tw.writeMPInt(pk.getY());
return tw.getBytes();
}
- public static byte[] encodeSSHDSASignature(DSASignature ds)
+ /**
+ * Convert from Java's signature ASN.1 encoding to the SSH spec.
+ * <p>
+ * Java ASN.1 encoding:
+ * <pre>
+ * SEQUENCE ::= {
+ * r INTEGER,
+ * s INTEGER
+ * }
+ * </pre>
+ */
+ public static byte[] encodeSSHDSASignature(byte[] ds)
{
TypesWriter tw = new TypesWriter();
tw.writeString("ssh-dss");
- byte[] r = ds.getR().toByteArray();
- byte[] s = ds.getS().toByteArray();
+ int len, index;
- byte[] a40 = new byte[40];
+ index = 3;
+ len = ds[index++] & 0xff;
+ byte[] r = new byte[len];
+ System.arraycopy(ds, index, r, 0, r.length);
+ index = index + len + 1;
+ len = ds[index++] & 0xff;
+ byte[] s = new byte[len];
+ System.arraycopy(ds, index, s, 0, s.length);
+
+ byte[] a40 = new byte[40];
+ /* Patch (unsigned) r and s into the target array. */
int r_copylen = (r.length < 20) ? r.length : 20;
@@ -78,22 +123,21 @@ public class DSASHA1Verify return tw.getBytes();
}
- public static DSASignature decodeSSHDSASignature(byte[] sig) throws IOException
+ public static byte[] decodeSSHDSASignature(byte[] sig) throws IOException
{
byte[] rsArray = null;
if (sig.length == 40)
{
/* OK, another broken SSH server. */
- rsArray = sig;
+ rsArray = sig;
}
else
{
- /* Hopefully a server obeing the standard... */
+ /* Hopefully a server obeying the standard... */
TypesReader tr = new TypesReader(sig);
String sig_format = tr.readString();
-
if (sig_format.equals("ssh-dss") == false)
throw new IOException("Peer sent wrong signature format");
@@ -106,105 +150,106 @@ public class DSASHA1Verify throw new IOException("Padding in DSA signature!");
}
- /* Remember, s and r are unsigned ints. */
-
- byte[] tmp = new byte[20];
-
- System.arraycopy(rsArray, 0, tmp, 0, 20);
- BigInteger r = new BigInteger(1, tmp);
-
- System.arraycopy(rsArray, 20, tmp, 0, 20);
- BigInteger s = new BigInteger(1, tmp);
-
- if (log.isEnabled())
- {
- log.log(30, "decoded ssh-dss signature: first bytes r(" + ((rsArray[0]) & 0xff) + "), s("
- + ((rsArray[20]) & 0xff) + ")");
+ int i = 0;
+ int j = 0;
+ byte[] tmp;
+
+ if (rsArray[0] == 0 && rsArray[1] == 0 && rsArray[2] == 0) {
+ j = ((rsArray[i++] << 24) & 0xff000000) | ((rsArray[i++] << 16) & 0x00ff0000)
+ | ((rsArray[i++] << 8) & 0x0000ff00) | ((rsArray[i++]) & 0x000000ff);
+ i += j;
+ j = ((rsArray[i++] << 24) & 0xff000000) | ((rsArray[i++] << 16) & 0x00ff0000)
+ | ((rsArray[i++] << 8) & 0x0000ff00) | ((rsArray[i++]) & 0x000000ff);
+ tmp = new byte[j];
+ System.arraycopy(rsArray, i, tmp, 0, j);
+ rsArray = tmp;
}
- return new DSASignature(r, s);
- }
-
- public static boolean verifySignature(byte[] message, DSASignature ds, DSAPublicKey dpk) throws IOException
- {
- /* Inspired by Bouncycastle's DSASigner class */
-
- SHA1 md = new SHA1();
- md.update(message);
- byte[] sha_message = new byte[md.getDigestLength()];
- md.digest(sha_message);
+ /* ASN.1 */
+ int frst = ((rsArray[0] & 0x80) != 0 ? 1 : 0);
+ int scnd = ((rsArray[20] & 0x80) != 0 ? 1 : 0);
- BigInteger m = new BigInteger(1, sha_message);
+ /* Calculate output length */
+ int length = rsArray.length + 6 + frst + scnd;
+ tmp = new byte[length];
- BigInteger r = ds.getR();
- BigInteger s = ds.getS();
+ /* DER-encoding to match Java */
+ tmp[0] = (byte) 0x30;
- BigInteger g = dpk.getG();
- BigInteger p = dpk.getP();
- BigInteger q = dpk.getQ();
- BigInteger y = dpk.getY();
-
- BigInteger zero = BigInteger.ZERO;
+ if (rsArray.length != 40)
+ throw new IOException("Peer sent corrupt signature");
+ /* Calculate length */
+ tmp[1] = (byte) 0x2c;
+ tmp[1] += frst;
+ tmp[1] += scnd;
- if (log.isEnabled())
- {
- log.log(60, "ssh-dss signature: m: " + m.toString(16));
- log.log(60, "ssh-dss signature: r: " + r.toString(16));
- log.log(60, "ssh-dss signature: s: " + s.toString(16));
- log.log(60, "ssh-dss signature: g: " + g.toString(16));
- log.log(60, "ssh-dss signature: p: " + p.toString(16));
- log.log(60, "ssh-dss signature: q: " + q.toString(16));
- log.log(60, "ssh-dss signature: y: " + y.toString(16));
- }
+ /* First item */
+ tmp[2] = (byte) 0x02;
- if (zero.compareTo(r) >= 0 || q.compareTo(r) <= 0)
- {
- log.log(20, "ssh-dss signature: zero.compareTo(r) >= 0 || q.compareTo(r) <= 0");
- return false;
- }
+ /* First item length */
+ tmp[3] = (byte) 0x14;
+ tmp[3] += frst;
- if (zero.compareTo(s) >= 0 || q.compareTo(s) <= 0)
- {
- log.log(20, "ssh-dss signature: zero.compareTo(s) >= 0 || q.compareTo(s) <= 0");
- return false;
- }
+ /* Copy in the data for first item */
+ System.arraycopy(rsArray, 0, tmp, 4 + frst, 20);
- BigInteger w = s.modInverse(q);
+ /* Second item */
+ tmp[4 + tmp[3]] = (byte) 0x02;
- BigInteger u1 = m.multiply(w).mod(q);
- BigInteger u2 = r.multiply(w).mod(q);
+ /* Second item length */
+ tmp[5 + tmp[3]] = (byte) 0x14;
+ tmp[5 + tmp[3]] += scnd;
- u1 = g.modPow(u1, p);
- u2 = y.modPow(u2, p);
+ /* Copy in the data for the second item */
+ System.arraycopy(rsArray, 20, tmp, 6 + tmp[3] + scnd, 20);
- BigInteger v = u1.multiply(u2).mod(p).mod(q);
+ /* Swap buffers */
+ rsArray = tmp;
- return v.equals(r);
+ return rsArray;
}
- public static DSASignature generateSignature(byte[] message, DSAPrivateKey pk, SecureRandom rnd)
+ public static boolean verifySignature(byte[] message, byte[] ds, DSAPublicKey dpk) throws IOException
{
- SHA1 md = new SHA1();
- md.update(message);
- byte[] sha_message = new byte[md.getDigestLength()];
- md.digest(sha_message);
-
- BigInteger m = new BigInteger(1, sha_message);
- BigInteger k;
- int qBitLength = pk.getQ().bitLength();
-
- do
- {
- k = new BigInteger(qBitLength, rnd);
+ try {
+ Signature s = Signature.getInstance("SHA1withDSA");
+ s.initVerify(dpk);
+ s.update(message);
+ return s.verify(ds);
+ } catch (NoSuchAlgorithmException e) {
+ IOException ex = new IOException("No such algorithm");
+ ex.initCause(e);
+ throw ex;
+ } catch (InvalidKeyException e) {
+ IOException ex = new IOException("No such algorithm");
+ ex.initCause(e);
+ throw ex;
+ } catch (SignatureException e) {
+ IOException ex = new IOException();
+ ex.initCause(e);
+ throw ex;
}
- while (k.compareTo(pk.getQ()) >= 0);
-
- BigInteger r = pk.getG().modPow(k, pk.getP()).mod(pk.getQ());
-
- k = k.modInverse(pk.getQ()).multiply(m.add((pk).getX().multiply(r)));
-
- BigInteger s = k.mod(pk.getQ());
+ }
- return new DSASignature(r, s);
+ public static byte[] generateSignature(byte[] message, DSAPrivateKey pk, SecureRandom rnd) throws IOException
+ {
+ try {
+ Signature s = Signature.getInstance("SHA1withDSA");
+ s.initSign(pk);
+ s.update(message);
+ return s.sign();
+ } catch (NoSuchAlgorithmException e) {
+ IOException ex = new IOException();
+ ex.initCause(e);
+ throw ex;
+ } catch (InvalidKeyException e) {
+ IOException ex = new IOException();
+ ex.initCause(e);
+ throw ex;
+ } catch (SignatureException e) {
+ IOException ex = new IOException();
+ ex.initCause(e);
+ throw ex;
+ }
}
}
|