2 files changed, 319 insertions, 0 deletions
diff --git a/dashboard/dashboard.go b/dashboard/dashboard.go
new file mode 100644
index 0000000..9b6dedd
--- /dev/null
+++ b/dashboard/dashboard.go
@@ -0,0 +1,132 @@
+package dashboard
+
+import (
+	"bytes"
+	"crypto/ed25519"
+	"encoding/base32"
+	"encoding/json"
+
+	"kesim.org/seal"
+	"kesim.org/seal/nizk/commit"
+)
+
+type Dashboard interface {
+	NewAuction(description *seal.SignedDescription) (auctionId string, e error)
+	Auctions(state AuctionState) map[string]*seal.SignedDescription
+	Join(auctionId string, commitment SignedCommitment, bidderId ed25519.PublicKey) error
+	Commitments(auctionId string) (bidders map[string]SignedCommitment, e error)
+	Publish(auctionId string, round uint8, message SignedMessage, bidderId ed25519.PublicKey) error
+	Messages(auctionId string, round uint8) (messages map[string]SignedMessage, e error)
+	Cancel(auctionId string, reason SignedMessage, bidderId ed25519.PublicKey) error
+	Result(auctionId string) (price uint64, winner ed25519.PublicKey, e error)
+}
+
+type SignedMessage struct {
+	Message   []byte
+	Signature []byte
+}
+
+type SignedCommitment struct {
+	*commit.Commitment
+	Signature []byte
+}
+
+type Error int
+
+const (
+	ErrUnknownError Error = iota
+
+	ErrSellerIncorrectSignature
+	ErrSellerAuctionExists
+
+	ErrAuctionUnknown
+	ErrAuctionNotStarted
+	ErrAuctionNotReady
+	ErrAuctionNotRunning
+	ErrAuctionFinished
+	ErrAuctionCanceled
+	ErrAuctionTimeout
+
+	ErrBidderUnknown
+	ErrBidderTimeout
+	ErrBidderEmptyMessage
+	ErrBidderIncorrectSignature
+	ErrBidderWrongRound
+	ErrBidderVerificationFailed
+)
+
+func (d Error) Error() string {
+	switch d {
+	case ErrUnknownError:
+		return "unknown error"
+
+	case ErrSellerIncorrectSignature:
+		return "incorrect seller signature"
+	case ErrSellerAuctionExists:
+		return "auction with that id already exists"
+
+	case ErrAuctionUnknown:
+		return "unknown auction"
+	case ErrAuctionNotStarted:
+		return "auction not started yet"
+	case ErrAuctionNotReady:
+		return "auction not ready"
+	case ErrAuctionNotRunning:
+		return "auction is not running"
+	case ErrAuctionFinished:
+		return "auction is finished"
+	case ErrAuctionTimeout:
+		return "action has timed out"
+	case ErrAuctionCanceled:
+		return "auction has been canceled"
+
+	case ErrBidderUnknown:
+		return "bidder is unknown"
+	case ErrBidderTimeout:
+		return "bidder has timed out"
+	case ErrBidderEmptyMessage:
+		return "empty message"
+	case ErrBidderIncorrectSignature:
+		return "incorrect signature from bidder"
+	case ErrBidderWrongRound:
+		return "wrong round"
+	case ErrBidderVerificationFailed:
+		return "round data couldn't be verified"
+
+	default:
+		panic("should not happen")
+	}
+}
+
+type AuctionState int
+
+const (
+	AuctionStateUnknown AuctionState = iota
+
+	AuctionStateReady
+	AuctionStateRunning
+	AuctionStateFinished
+	AuctionStateCanceled
+	AuctionStateTimeout
+
+	AuctionStateLAST
+)
+
+func (s *SignedMessage) Verify(pubkey ed25519.PublicKey) bool {
+	return ed25519.Verify(pubkey, s.Message, s.Signature)
+}
+
+func (s *SignedCommitment) Verify(pubkey ed25519.PublicKey) bool {
+	buf := &bytes.Buffer{}
+	e := json.NewEncoder(buf).Encode(s.Commitment)
+	if e != nil {
+		// TODO: log message?
+		return false
+	}
+
+	return ed25519.Verify(pubkey, buf.Bytes(), s.Signature)
+}
+
+func Pub2String(pubkey ed25519.PublicKey) string {
+	return base32.StdEncoding.EncodeToString(pubkey)
+}
+\ No newline at end of file
diff --git a/dashboard/inmemory.go b/dashboard/inmemory.go
new file mode 100644
index 0000000..82412cb
--- /dev/null
+++ b/dashboard/inmemory.go
@@ -0,0 +1,187 @@
+package dashboard
+
+import (
+	"crypto/ed25519"
+	"fmt"
+	"sync"
+
+	"kesim.org/seal"
+)
+
+type inmemory struct {
+	sync.RWMutex
+
+	auctions map[string]*auction
+}
+
+func NewInMemoryDashboard() *inmemory {
+	return &inmemory{}
+}
+
+type auction struct {
+	sync.RWMutex
+
+	description *seal.SignedDescription
+	state       AuctionState
+	round       uint8 // which bit has been completed
+
+	commitments map[string]SignedCommitment
+	messages    map[string][]SignedMessage // per-bidder and per-round messages, pre-allocated.
+}
+
+func (m *inmemory) NewAuction(description *seal.SignedDescription) (auctionId string, e error) {
+	if ok, e := description.Verify(); e != nil {
+		return "", e
+	} else if !ok {
+		return "", ErrSellerIncorrectSignature
+	}
+
+	auctionId, e = description.Hash()
+	if e != nil {
+		return "", e
+	}
+
+	auction := &auction{
+		description: description,
+		state:       AuctionStateReady,
+		messages:    make(map[string][]SignedMessage),
+	}
+
+	m.Lock()
+	defer m.Unlock()
+
+	if _, exists := m.auctions[auctionId]; exists {
+		return "", ErrSellerAuctionExists
+	}
+	m.auctions[auctionId] = auction
+
+	return auctionId, e
+
+}
+
+func (m *inmemory) Auctions(state AuctionState) map[string]*seal.SignedDescription {
+	if state == AuctionStateUnknown || state >= AuctionStateLAST {
+		return nil
+	}
+
+	m.RLock()
+	defer m.RUnlock()
+
+	r := make(map[string]*seal.SignedDescription)
+	for id, auction := range m.auctions {
+		if auction.state == state {
+			r[id] = auction.description
+		}
+	}
+	return r
+}
+
+func (m *inmemory) getAuction(auctionId string) (*auction, error) {
+	m.RLock()
+	defer m.RUnlock()
+
+	auction, exists := m.auctions[auctionId]
+	if !exists {
+		return nil, ErrAuctionUnknown
+
+	}
+
+	return auction, nil
+}
+
+func (m *inmemory) Join(auctionId string,
+	commitment SignedCommitment,
+	pubkey ed25519.PublicKey) error {
+
+	// Check signature first
+	if !commitment.Verify(pubkey) {
+		return ErrBidderIncorrectSignature
+	}
+
+	bidderId := Pub2String(pubkey)
+
+	auction, e := m.getAuction(auctionId)
+	if e != nil {
+		return e
+	}
+	// We allow overwriting
+	auction.Lock()
+	defer auction.Unlock()
+	if auction.state != AuctionStateReady {
+		return ErrAuctionNotReady
+	}
+	auction.commitments[bidderId] = commitment
+	auction.messages[bidderId] = make([]SignedMessage, auction.description.BitLength)
+
+	return nil
+}
+
+func (m *inmemory) Commitments(auctionId string) (bidders map[string]SignedCommitment, e error) {
+	auction, e := m.getAuction(auctionId)
+	if e != nil {
+		return nil, e
+	}
+
+	auction.RLock()
+	defer auction.RUnlock()
+
+	bidders = make(map[string]SignedCommitment)
+	for id, commitment := range auction.commitments {
+		bidders[id] = commitment
+	}
+	return bidders, nil
+}
+
+func (m *inmemory) Publish(auctionId string, round uint8, message SignedMessage, pubkey ed25519.PublicKey) error {
+	if len(message.Message) == 0 {
+		return ErrBidderEmptyMessage
+	}
+
+	// check signature first
+	if !message.Verify(pubkey) {
+		return ErrBidderIncorrectSignature
+	}
+
+	bidderId := Pub2String(pubkey)
+
+	auction, e := m.getAuction(auctionId)
+	if e != nil {
+		return e
+	}
+
+	auction.Lock()
+	defer auction.Unlock()
+
+	if auction.state == AuctionStateFinished {
+		return ErrAuctionFinished
+	} else if auction.state != AuctionStateRunning {
+		return ErrAuctionNotRunning
+	} else if auction.round != round {
+		return ErrBidderWrongRound
+	}
+
+	messages, ok := auction.messages[bidderId]
+	if !ok {
+		return ErrBidderUnknown
+	}
+	messages[auction.round] = message
+
+	completed := true
+
+	for _, messages := range auction.messages {
+		completed = completed && len(messages[auction.round].Message) > 0
+	}
+
+	if completed {
+		auction.round += 1
+		if auction.round == auction.description.BitLength {
+			auction.state = AuctionStateFinished
+		}
+	}
+
+	return nil
+}
+
+func (m *inmemory) Messages(auctionId string, round uint8) (messages map[string]SignedMessage, e error) {
+	return nil, fmt.Errorf("inmemory.Messages not implemented")
+}
+\ No newline at end of file