Fix Contact code formatting and go mod

go.mod

@@ -19,7 +19,7 @@ require (
 	github.com/spf13/viper v1.7.1
 	gitlab.com/elixxir/bloomfilter v0.0.0-20200930191214-10e9ac31b228
 	gitlab.com/elixxir/comms v0.0.4-0.20201229200853-c403d72e877c
-	gitlab.com/elixxir/crypto v0.0.7-0.20201222203132-9b4cc1ae3da6
+	gitlab.com/elixxir/crypto v0.0.7-0.20210104173655-8a83c8beb556
 	gitlab.com/elixxir/ekv v0.1.4-0.20201217220111-9c7e8be21577
 	gitlab.com/elixxir/primitives v0.0.3-0.20201229212305-2ab1e938b1cb
 	gitlab.com/xx_network/comms v0.0.4-0.20201222193955-56206d700360

go.sum

@@ -266,6 +266,8 @@ gitlab.com/elixxir/crypto v0.0.3 h1:znCt/x2bL4y8czTPaaFkwzdgSgW3BJc/1+dxyf1jqVw=
 gitlab.com/elixxir/crypto v0.0.3/go.mod h1:ZNgBOblhYToR4m8tj4cMvJ9UsJAUKq+p0gCp07WQmhA=
 gitlab.com/elixxir/crypto v0.0.7-0.20201222203132-9b4cc1ae3da6 h1:Vyf2wJ1/CoHLznATpI+z84OJQ+sgAbpVLT9P1CNjSVI=
 gitlab.com/elixxir/crypto v0.0.7-0.20201222203132-9b4cc1ae3da6/go.mod h1:NsIzH+TN592lMcmJGVzxUE64dObXuci7jo0qajyGahI=
+gitlab.com/elixxir/crypto v0.0.7-0.20210104173655-8a83c8beb556 h1:TiFwplcpE2QmSyrSfOn97MfPxlKwBE2LSaoWeQAEgQo=
+gitlab.com/elixxir/crypto v0.0.7-0.20210104173655-8a83c8beb556/go.mod h1:NsIzH+TN592lMcmJGVzxUE64dObXuci7jo0qajyGahI=
 gitlab.com/elixxir/ekv v0.1.4-0.20201217220111-9c7e8be21577 h1:qT3ZO9GbKv7PcmakATsXsUdzn/hlm817ETOT/csDIak=
 gitlab.com/elixxir/ekv v0.1.4-0.20201217220111-9c7e8be21577/go.mod h1:e6WPUt97taFZe5PFLPb1Dupk7tqmDCTQu1kkstqJvw4=
 gitlab.com/elixxir/primitives v0.0.0-20200731184040-494269b53b4d/go.mod h1:OQgUZq7SjnE0b+8+iIAT2eqQF+2IFHn73tOo+aV11mg=

interfaces/contact/contact.go

@@ -61,8 +61,8 @@ func (c Contact) Marshal() []byte {
 	if c.ID != nil {
 		buff.Write(c.ID.Marshal())
 	} else {
-		emptyID := make([]byte, id.ArrIDLen)
-		buff.Write(emptyID)
+		// Handle nil ID
+		buff.Write(make([]byte, id.ArrIDLen))
 	}
 
 	// Write DhPubKey
@@ -83,7 +83,7 @@ func Unmarshal(b []byte) (Contact, error) {
 	var err error
 	buff := bytes.NewBuffer(b)
 
-	// Get size (in bytes) of each field
+	// Get size of each field
 	dhPubKeySize, _ := binary.Varint(buff.Next(sizeByteLength))
 	ownershipProofSize, _ := binary.Varint(buff.Next(sizeByteLength))
 	factsSize, _ := binary.Varint(buff.Next(sizeByteLength))
@@ -104,23 +104,23 @@ func Unmarshal(b []byte) (Contact, error) {
 		// Handle nil key
 		c.DhPubKey = nil
 	} else {
-		err = c.DhPubKey.BinaryDecode(buff.Next(int(dhPubKeySize)))
-		if err != nil {
+		if err = c.DhPubKey.BinaryDecode(buff.Next(int(dhPubKeySize))); err != nil {
 			return Contact{}, errors.Errorf("Failed to binary decode Contact DhPubKey: %+v", err)
 		}
 	}
 
 	// Get OwnershipProof
-	c.OwnershipProof = buff.Next(int(ownershipProofSize))
-	if len(c.OwnershipProof) == 0 {
+	if ownershipProofSize == 0 {
 		// Handle nil OwnershipProof
 		c.OwnershipProof = nil
+	} else {
+		c.OwnershipProof = buff.Next(int(ownershipProofSize))
 	}
 
 	// Get and unstringify fact list
 	c.Facts, _, err = fact.UnstringifyFactList(string(buff.Next(int(factsSize))))
 	if err != nil {
-		return Contact{}, errors.Errorf("Failed to unstringify Fact List: %+v", err)
+		return Contact{}, errors.Errorf("Failed to unstringify Contact fact list: %+v", err)
 	}
 
 	return c, nil