Gossip Documentation

CTng/gossip/Readme.md

@@ -0,0 +1,16 @@
+# Gossip Package
+
+## Contents
+- `process_object.go`: Functions for processing a new object (valid, invalid, or duplicate)
+- `gossiper.go`: Functions for actions that the Gossiper can complete as a client
+  - Sending to Owner
+  - Gossiping to connections
+  - Accusing (unused currently)
+- `gossip_object.go`: Functions for working with Gossip Objects
+-   `accusations.go`: Describes the system for keeping track of accusations of each entity (with `accusation_validation.go` calls).
+- Note that many calls are made between these files and the HTTP server. in the future, more gossiper logic could be moved from the server package to this one.
+
+## `Types.go`
+- Defines the Gossip Object and explains some design choices with Gossip_object_IDs.
+  - Defines constants for the field types of CTng
+- Defines the Gossiper Context object for managing server state

CTng/gossip/accusations.go

@@ -6,6 +6,10 @@ import (
 	"fmt"
 )
 
+/*This file mainly deals with Proof of Misbehavior generated after receiving threshold number of accusations (as part of the process accusations).
+This file also contains the process accusations function for the gossiper to invoke.
+*/
+
 func Process_Accusation(new_acc Gossip_object, accs *AccusationDB, c *crypto.CryptoConfig) (*Gossip_object, bool, error) {
 	// Convert signature string
 	p_sig, err := crypto.SigFragmentFromString(new_acc.Signature[0])

CTng/gossip/gossip_object.go

@@ -1,13 +1,11 @@
 package gossip
 
 import (
-	"CTng/config"
 	"CTng/crypto"
 	"encoding/json"
 	"errors"
 	"fmt"
 	"log"
-	"reflect"
 	"time"
 )
 
@@ -54,34 +52,9 @@ func unpack_object(obj []byte) (depacked Gossip_object) {
 	return depack
 }
 
-//checks if Gossip_object_ID already exists in map returns bool rn but I want to change it to just add the object to storage
-func check_object_data(conf *config.Gossiper_config, obj Gossip_object, stor Gossip_Storage) {
-	obj_ID := obj.GetID(conf.Public.Period_interval)
-	// if object exists, make sure values match
-	if stored_object, exists := stor[obj_ID]; exists {
-
-		check_stored := reflect.ValueOf(&stored_object).Elem()
-		given_object := reflect.ValueOf(&obj).Elem()
-
-		for i := 0; i < check_stored.NumField(); i++ {
-			temp_stored := check_stored.Field(i).Interface()
-			temp_given := given_object.Field(i).Interface()
-			if temp_given == temp_stored {
-				continue
-			} else {
-				log.Fatal("Error given object does not match stored object")
-			}
-		}
-
-	} else {
-		stor[obj_ID] = obj
-	}
-
-}
-
 //verify gossip pom takes a gossip object as input
 func Verify_gossip_pom(g Gossip_object, c *crypto.CryptoConfig) error {
-	if g.Type == "http://ctng.uconn.edu/001" {
+	if g.Type == GOSSIP_POM {
 		//gossip pom refers to Pom generated due to conflicting information
 		//From Finn's gossiper design, gossip poms are defaulted to have 2 non empty fields for signature and paypload
 		if g.Signature[1] != "" && g.Payload[1] != "" {
@@ -141,7 +114,6 @@ func Verfiy_PayloadThreshold(g Gossip_object, c *crypto.CryptoConfig) error {
 // Verifies RSAsig matches payload, wait.... i think this just works out of the box with what we have
 func Verify_RSAPayload(g Gossip_object, c *crypto.CryptoConfig) error {
 	if g.Signature[0] != "" && g.Payload[0] != "" {
-		// TODO: convert RSASig from and to a string.
 		sig, err := crypto.RSASigFromString(g.Signature[0])
 		if err != nil {
 			return errors.New(No_Sig_Match)
@@ -153,7 +125,10 @@ func Verify_RSAPayload(g Gossip_object, c *crypto.CryptoConfig) error {
 	}
 }
 
-//Verifies Gossip object based on Type
+//Verifies Gossip object based on the type:
+//STH and Revocations use RSA
+//Trusted information Fragments use BLS SigFragments
+//PoMs use Threshold signatures
 func (g Gossip_object) Verify(c *crypto.CryptoConfig) error {
 	// If everything Verified correctly, we return nil
 	switch g.Type {

CTng/gossip/gossiper.go

@@ -80,7 +80,5 @@ func SendToOwner(c *GossiperContext, obj Gossip_object) {
 		defer resp.Body.Close()
 		fmt.Println("Owner responded with " + resp.Status)
 	}
-
 	// Handling errors from owner could go here.
-
 }

CTng/gossip/process_object.go

@@ -46,7 +46,7 @@ func ProcessValidObject(c *GossiperContext, obj Gossip_object) {
 // Process a valid gossip object which is a duplicate to another one.
 // If the signature/payload is identical, then we can safely ignore the duplicate.
 // Otherwise, we generate a PoM for two objects sent in the same period.
-func ProcessDuplicateObject(c *GossiperContext, obj Gossip_object, dup Gossip_object) err {
+func ProcessDuplicateObject(c *GossiperContext, obj Gossip_object, dup Gossip_object) error {
 	if obj.Signature == dup.Signature &&
 		obj.Payload == dup.Payload {
 		return nil
@@ -63,8 +63,9 @@ func ProcessDuplicateObject(c *GossiperContext, obj Gossip_object, dup Gossip_ob
 		c.StoreObject(pom)
 		c.HasPom[obj.Payload[0]] = true
 		// Currently, we don't send PoMs. but if we did, we could do it here.
-		SendToOwner(c, pom)
-		return errors.New("Proof of Misbhevior Generated")
+		// Send to owner.
+		defer SendToOwner(c, pom)
+		return errors.New("Proof of Misbehavior Generated")
 	}
 }
 

CTng/gossip/types.go

@@ -58,13 +58,16 @@ type Gossip_object struct {
 	Payload [2]string `json:"payload,omitempty"`
 }
 
+// The identifier for a Gossip Object is the (Application,Type,Signer,Period) tuple.
+// Gossip_object.GetID(time Period) returns the ID of an object, accepting a period to be used for conversion.
 type Gossip_object_ID struct {
 	Application string `json:"application"`
 	Type        string `json:"type"`
 	Signer      string `json:"signer"`
 	Period      string `json:"period"`
 }
 
+//Simple mapping of object IDs to objects.
 type Gossip_Storage map[Gossip_object_ID]Gossip_object
 
 // Gossiper Context
@@ -84,6 +87,7 @@ type GossiperContext struct {
 	HasPom map[string]bool
 }
 
+// Saves the Storage object to the value in c.StorageFile.
 func (c *GossiperContext) SaveStorage() error {
 	storageList := []Gossip_object{}
 	for _, gossipObject := range *c.Storage {
@@ -93,7 +97,7 @@ func (c *GossiperContext) SaveStorage() error {
 	return err
 }
 
-// Read every gossip object from c.StorageFile().
+// Read every gossip object from c.StorageFile.
 // Store all files in c.Storage by their ID.
 func (c *GossiperContext) LoadStorage() error {
 	storageList := []Gossip_object{}