Added Kex integration test

src/itest/groovy/com/hierynomus/sshj/transport/kex/KexSpec.groovy

@@ -0,0 +1,46 @@
+package com.hierynomus.sshj.transport.kex
+
+import com.hierynomus.sshj.IntegrationBaseSpec
+import com.hierynomus.sshj.transport.mac.Macs
+import net.schmizz.sshj.DefaultConfig
+import net.schmizz.sshj.transport.kex.Curve25519DH
+import net.schmizz.sshj.transport.kex.Curve25519SHA256
+import net.schmizz.sshj.transport.kex.DH
+import net.schmizz.sshj.transport.kex.DHGexSHA1
+import net.schmizz.sshj.transport.kex.DHGexSHA256
+import net.schmizz.sshj.transport.kex.ECDH
+import net.schmizz.sshj.transport.kex.ECDHNistP
+import spock.lang.Unroll
+
+class KexSpec extends IntegrationBaseSpec {
+
+    @Unroll
+    def "should correctly connect with #kex Key Exchange"() {
+        given:
+        def cfg = new DefaultConfig()
+        cfg.setKeyExchangeFactories(kexFactory)
+        def client = getConnectedClient(cfg)
+
+        when:
+        client.authPublickey(USERNAME, KEYFILE)
+
+        then:
+        client.authenticated
+
+        where:
+        kexFactory << [DHGroups.Group1SHA1(),
+                       DHGroups.Group14SHA1(),
+                       DHGroups.Group14SHA256(),
+                       DHGroups.Group16SHA512(),
+                       DHGroups.Group18SHA512(),
+                       new DHGexSHA1.Factory(),
+                       new DHGexSHA256.Factory(),
+                       new Curve25519SHA256.Factory(),
+                       new Curve25519SHA256.FactoryLibSsh(),
+                       new ECDHNistP.Factory256(),
+                       new ECDHNistP.Factory384(),
+                       new ECDHNistP.Factory521()]
+        kex = kexFactory.name
+    }
+
+}