public boolean authenticatePublicKey()

in cvs/trilead-ssh2-build213/src/com/trilead/ssh2/auth/AuthenticationManager.java [145:248]
79 lines of code
7 McCabe index (conditional complexity)

	public boolean authenticatePublicKey(String user, char[] PEMPrivateKey, String password, SecureRandom rnd)
			throws IOException
	{
		try
		{
			initialize(user);

			if (methodPossible("publickey") == false)
				throw new IOException("Authentication method publickey not supported by the server at this stage.");

			Object key = PEMDecoder.decode(PEMPrivateKey, password);

			if (key instanceof DSAPrivateKey)
			{
				DSAPrivateKey pk = (DSAPrivateKey) key;

				byte[] pk_enc = DSASHA1Verify.encodeSSHDSAPublicKey(pk.getPublicKey());

				TypesWriter tw = new TypesWriter();

				byte[] H = tm.getSessionIdentifier();

				tw.writeString(H, 0, H.length);
				tw.writeByte(Packets.SSH_MSG_USERAUTH_REQUEST);
				tw.writeString(user);
				tw.writeString("ssh-connection");
				tw.writeString("publickey");
				tw.writeBoolean(true);
				tw.writeString("ssh-dss");
				tw.writeString(pk_enc, 0, pk_enc.length);

				byte[] msg = tw.getBytes();

				DSASignature ds = DSASHA1Verify.generateSignature(msg, pk, rnd);

				byte[] ds_enc = DSASHA1Verify.encodeSSHDSASignature(ds);

				PacketUserauthRequestPublicKey ua = new PacketUserauthRequestPublicKey("ssh-connection", user,
						"ssh-dss", pk_enc, ds_enc);
				tm.sendMessage(ua.getPayload());
			}
			else if (key instanceof RSAPrivateKey)
			{
				RSAPrivateKey pk = (RSAPrivateKey) key;

				byte[] pk_enc = RSASHA1Verify.encodeSSHRSAPublicKey(pk.getPublicKey());

				TypesWriter tw = new TypesWriter();
				{
					byte[] H = tm.getSessionIdentifier();

					tw.writeString(H, 0, H.length);
					tw.writeByte(Packets.SSH_MSG_USERAUTH_REQUEST);
					tw.writeString(user);
					tw.writeString("ssh-connection");
					tw.writeString("publickey");
					tw.writeBoolean(true);
					tw.writeString("ssh-rsa");
					tw.writeString(pk_enc, 0, pk_enc.length);
				}

				byte[] msg = tw.getBytes();

				RSASignature ds = RSASHA1Verify.generateSignature(msg, pk);

				byte[] rsa_sig_enc = RSASHA1Verify.encodeSSHRSASignature(ds);

				PacketUserauthRequestPublicKey ua = new PacketUserauthRequestPublicKey("ssh-connection", user,
						"ssh-rsa", pk_enc, rsa_sig_enc);
				tm.sendMessage(ua.getPayload());
			}
			else
			{
				throw new IOException("Unknown private key type returned by the PEM decoder.");
			}

			byte[] ar = getNextMessage();

			if (ar[0] == Packets.SSH_MSG_USERAUTH_SUCCESS)
			{
				authenticated = true;
				tm.removeMessageHandler(this, 0, 255);
				return true;
			}

			if (ar[0] == Packets.SSH_MSG_USERAUTH_FAILURE)
			{
				PacketUserauthFailure puf = new PacketUserauthFailure(ar, 0, ar.length);

				remainingMethods = puf.getAuthThatCanContinue();
				isPartialSuccess = puf.isPartialSuccess();

				return false;
			}

			throw new IOException("Unexpected SSH message (type " + ar[0] + ")");

		}
		catch (IOException e)
		{
			tm.close(e, false);
			throw (IOException) new IOException("Publickey authentication failed.").initCause(e);
		}
	}