KademliaMVar.client and Kademlia.findNode (#49)

* KademliaMVar.client and Kademlia.findNode

* scalariform formatting & tiny bugfix

* sbt ops for travis?

* constant b64seed in Contact

* merge master

* compilation bugfix

* possible fix

* review fixes

js/src/main/scala/fluence/crypto/algorithm/EcdsaJS.scala

@@ -19,6 +19,7 @@ package fluence.crypto.algorithm
 
 import cats.data.EitherT
 import cats.{ Monad, MonadError }
+import fluence.crypto.SignAlgo
 import fluence.crypto.facade.EC
 import fluence.crypto.hash.{ CryptoHasher, JsCryptoHasher }
 import fluence.crypto.keypair.KeyPair
@@ -82,5 +83,7 @@ class EcdsaJS(ec: EC, hasher: Option[CryptoHasher[Array[Byte], Array[Byte]]]) ex
 }
 
 object EcdsaJS {
-  def ecdsa_secp256k1_sha256 = new EcdsaJS(new EC("secp256k1"), Some(JsCryptoHasher.Sha256))
+  val ecdsa_secp256k1_sha256 = new EcdsaJS(new EC("secp256k1"), Some(JsCryptoHasher.Sha256))
+
+  val signAlgo = new SignAlgo("ecdsa/secp256k1/sha256/js", ecdsa_secp256k1_sha256)
 }

js/src/test/scala/fluence/crypto/EcdsaJSSpec.scala

@@ -55,7 +55,7 @@ class EcdsaJSSpec extends WordSpec with Matchers {
     }
 
     "correctly work with signer and checker" in {
-      val algo = new SignAlgo(EcdsaJS.ecdsa_secp256k1_sha256)
+      val algo = EcdsaJS.signAlgo
       val keys = algo.generateKeyPair().extract
       val signer = algo.signer(keys)
 
@@ -69,7 +69,7 @@ class EcdsaJSSpec extends WordSpec with Matchers {
     }
 
     "throw an errors on invalid data" in {
-      val algo = new SignAlgo(EcdsaJS.ecdsa_secp256k1_sha256)
+      val algo = EcdsaJS.signAlgo
       val keys = algo.generateKeyPair().extract
       val signer = algo.signer(keys)
       val data = rndByteVector(10)

jvm/src/main/scala/fluence/crypto/algorithm/Ecdsa.scala

@@ -23,6 +23,7 @@ import java.security.interfaces.ECPrivateKey
 
 import cats.data.EitherT
 import cats.Monad
+import fluence.crypto.SignAlgo
 import fluence.crypto.hash.{ CryptoHasher, JdkCryptoHasher }
 import fluence.crypto.keypair.KeyPair
 import org.bouncycastle.jce.ECNamedCurveTable
@@ -128,5 +129,7 @@ object Ecdsa {
    * `NONEwithECDSA with sha-256 hasher` Preferably the size of the key is greater than or equal to the digest algorithm
    * don't use `SHA256WithECDSA` because of non-compatibility with javascript libraries
    */
-  def ecdsa_secp256k1_sha256 = new Ecdsa("secp256k1", "NONEwithECDSA", Some(JdkCryptoHasher.Sha256))
+  val ecdsa_secp256k1_sha256 = new Ecdsa("secp256k1", "NONEwithECDSA", Some(JdkCryptoHasher.Sha256))
+
+  val signAlgo = new SignAlgo("ecdsa_secp256k1_sha256", ecdsa_secp256k1_sha256)
 }

jvm/src/test/scala/fluence/crypto/SignatureSpec.scala

@@ -58,7 +58,7 @@ class SignatureSpec extends WordSpec with Matchers {
     }
 
     "correctly work with signer and checker" in {
-      val algo = new SignAlgo(Ecdsa.ecdsa_secp256k1_sha256)
+      val algo = Ecdsa.signAlgo
       val keys = algo.generateKeyPair().extract
       val signer = algo.signer(keys)
 
@@ -72,7 +72,7 @@ class SignatureSpec extends WordSpec with Matchers {
     }
 
     "throw an errors on invalid data" in {
-      val algo = new SignAlgo(Ecdsa.ecdsa_secp256k1_sha256)
+      val algo = Ecdsa.signAlgo
       val keys = algo.generateKeyPair().extract
       val signer = algo.signer(keys)
       val data = rndByteVector(10)
@@ -84,7 +84,7 @@ class SignatureSpec extends WordSpec with Matchers {
     }
 
     "store and read key from file" in {
-      val algo = new SignAlgo(Ecdsa.ecdsa_secp256k1_sha256)
+      val algo = Ecdsa.signAlgo
       val keys = algo.generateKeyPair().extract
 
       val keyFile = File.createTempFile("test", "")

src/main/scala/fluence/crypto/SignAlgo.scala

@@ -28,9 +28,10 @@ import scala.language.higherKinds
 
 /**
  * Class for generation keys, signers and checkers
+ * @param name Algo name for debugging
  * @param algo implementation of sign alghoritms, e.g. ECDSA
  */
-class SignAlgo(algo: KeyGenerator with SignatureFunctions) {
+class SignAlgo(name: String, algo: KeyGenerator with SignatureFunctions) {
 
   def generateKeyPair[F[_] : Monad](seed: Option[ByteVector] = None): EitherT[F, CryptoErr, KeyPair] =
     algo.generateKeyPair(seed.map(_.toArray))
@@ -38,13 +39,19 @@ class SignAlgo(algo: KeyGenerator with SignatureFunctions) {
   def signer(kp: KeyPair): Signer = new Signer {
     override def sign[F[_] : Monad](plain: ByteVector): EitherT[F, CryptoErr, Signature] = algo.sign(kp, plain)
     override def publicKey: KeyPair.Public = kp.publicKey
+
+    override def toString: String = s"Signer($name, ${kp.publicKey})"
   }
 
   def checker: SignatureChecker = new SignatureChecker {
     override def check[F[_] : Monad](signature: Signature, plain: ByteVector): EitherT[F, CryptoErr, Unit] = algo.verify(signature, plain)
+
+    override def toString: String = s"SignatureChecker($name)"
   }
+
+  override def toString: String = s"SignAlgo($name)"
 }
 
 object SignAlgo {
-  val dumb = new SignAlgo(new DumbSign())
+  val dumb = new SignAlgo("dumb", new DumbSign())
 }

src/main/scala/fluence/crypto/signature/Signer.scala

@@ -25,6 +25,9 @@ import scodec.bits.ByteVector
 
 import scala.language.higherKinds
 
+/**
+ * Wraps public and private key, along with signing algorithm, to produce signatures
+ */
 trait Signer {
   def publicKey: KeyPair.Public