From c98e80ccc085b5fc87582f8630d8b50f153acdb2 Mon Sep 17 00:00:00 2001
From: Özgür Kesim <oec@codeblau.de>
Date: Tue, 9 Apr 2024 19:22:47 +0200
Subject: seal: added verifier of descriptions

---
 auction.go | 46 ++++++++++++++++++++++++++++++++++++----------
 1 file changed, 36 insertions(+), 10 deletions(-)

diff --git a/auction.go b/auction.go
index 78b9af6..df1d372 100644
--- a/auction.go
+++ b/auction.go
@@ -1,9 +1,14 @@
 package seal
 
 import (
-	"crypto"
-	"net/url"
+	"bytes"
+	"crypto/ed25519"
+	"crypto/sha512"
+	"encoding/base32"
+	"encoding/json"
 	"time"
+
+	"kesim.org/seal/nizk/commit"
 )
 
 type Type int
@@ -16,33 +21,54 @@ const (
 // Auction describes the asset of an auction and other
 // relevant meta-data
 type Description struct {
-	DashboardUrl    *url.URL // can be empty
 	Start           time.Time
 	End             time.Time
 	RoundTimeout    time.Duration // Timeout per round by which all responses must have arrived
 	BitLength       uint8         // Length of the price encoding
 	Currency        string
 	Type            Type
-	SellerPublicKey crypto.PublicKey // Public key of the Seller
+	SellerPublicKey ed25519.PublicKey // Public key of the Seller
 }
 
 // The SignedAuction contains an Auction and the signature,
 // signed by the seller's public key off the SHA512 hash of
 // the normalized JSON-object.
-// TODO(oec): normalized?
-type SignedDesciption struct {
+type SignedDescription struct {
 	Description
-	SellerSignature string
+	SellerSignature []byte
 }
 
 // Auction is the simple interface for the engine
 type Auction interface {
-	Join(bidder Bidder)
-	Received(msg []byte) error
+	Join(bidder Bidder)                   // A bidder calls this to join the auction
+	Message(msg []byte, sig []byte) error // A bidder uses this method to publish a message
 }
 
 // Bidder is the interface that the Auction engine uses to communicate
 type Bidder interface {
+	Commitment() *commit.Commitment
+	Start(map[string]*commit.Commitment)
 	Result()
-	Send(msg []byte, sig []byte) error
+	Receive(msg []byte) error
+}
+
+func (sd *SignedDescription) Verify() (bool, error) {
+	// TODO: need to normalize this encoding
+	buf := &bytes.Buffer{}
+	e := json.NewEncoder(buf).Encode(sd.Description)
+	if e != nil {
+		return false, e
+	}
+	r := ed25519.Verify(sd.SellerPublicKey, buf.Bytes(), sd.SellerSignature)
+	return r, nil
 }
+
+func (d *Description) Hash() (hash string, e error) {
+	buf := &bytes.Buffer{}
+	e = json.NewEncoder(buf).Encode(d)
+	if e != nil {
+		return "", e
+	}
+	h := sha512.Sum512(buf.Bytes())
+	return base32.StdEncoding.EncodeToString(h[:]), nil
+}
\ No newline at end of file
-- 
cgit v1.2.3