Merge pull request #3 from corestario/feat/random-seeds

feat: added configurable random seeds

Author: zavgorodnii

share/dkg/pedersen/dkg.go

@@ -173,7 +173,7 @@ func NewDistKeyHandler(c *Config) (*DistKeyGenerator, error) {
 	if c.Share != nil {
 		// resharing case
 		secretCoeff := c.Share.Share.V
-		dealer, err = vss.NewDealer(c.Suite, c.Longterm, secretCoeff, c.NewNodes, newThreshold)
+		dealer, err = vss.NewDealer(c.Suite, c.Longterm, secretCoeff, c.NewNodes, newThreshold, random.New(c.Reader))
 		canIssue = true
 	} else if !isResharing && newPresent {
 		// fresh DKG case
@@ -185,7 +185,7 @@ func NewDistKeyHandler(c *Config) (*DistKeyGenerator, error) {
 			randomStream = random.New(c.Reader)
 		}
 		secretCoeff := c.Suite.Scalar().Pick(randomStream)
-		dealer, err = vss.NewDealer(c.Suite, c.Longterm, secretCoeff, c.NewNodes, newThreshold)
+		dealer, err = vss.NewDealer(c.Suite, c.Longterm, secretCoeff, c.NewNodes, newThreshold, randomStream)
 		canIssue = true
 		c.OldNodes = c.NewNodes
 		oidx, oldPresent = findPub(c.OldNodes, pub)
@@ -242,12 +242,14 @@ func NewDistKeyHandler(c *Config) (*DistKeyGenerator, error) {
 
 // NewDistKeyGenerator returns a dist key generator ready to create a fresh
 // distributed key with the regular DKG protocol.
-func NewDistKeyGenerator(suite Suite, longterm kyber.Scalar, participants []kyber.Point, t int) (*DistKeyGenerator, error) {
+func NewDistKeyGenerator(suite Suite, longterm kyber.Scalar, participants []kyber.Point, t int, reader io.Reader) (*DistKeyGenerator, error) {
 	c := &Config{
-		Suite:     suite,
-		Longterm:  longterm,
-		NewNodes:  participants,
-		Threshold: t,
+		Suite:          suite,
+		Longterm:       longterm,
+		NewNodes:       participants,
+		Threshold:      t,
+		Reader:         reader,
+		UserReaderOnly: true,
 	}
 	return NewDistKeyHandler(c)
 }

share/vss/pedersen/vss.go

@@ -117,19 +117,20 @@ type Justification struct {
 // RECOMMENDED to use a threshold higher or equal than what the method
 // MinimumT() returns, otherwise it breaks the security assumptions of the whole
 // scheme. It returns an error if the t is less than or equal to 2.
-func NewDealer(suite Suite, longterm, secret kyber.Scalar, verifiers []kyber.Point, t int) (*Dealer, error) {
+func NewDealer(suite Suite, longterm, secret kyber.Scalar, verifiers []kyber.Point, t int, reader cipher.Stream) (*Dealer, error) {
 	d := &Dealer{
 		suite:     suite,
 		long:      longterm,
 		secret:    secret,
 		verifiers: verifiers,
+		reader:    reader,
 	}
 	if !validT(t, verifiers) {
 		return nil, fmt.Errorf("dealer: t %d invalid", t)
 	}
 	d.t = t
 
-	f := share.NewPriPoly(d.suite, d.t, d.secret, suite.RandomStream())
+	f := share.NewPriPoly(d.suite, d.t, d.secret, reader)
 	d.pub = d.suite.Point().Mul(d.long, nil)
 
 	// Compute public polynomial coefficients
@@ -181,7 +182,7 @@ func (d *Dealer) EncryptedDeal(i int) (*EncryptedDeal, error) {
 		return nil, errors.New("dealer: wrong index to generate encrypted deal")
 	}
 	// gen ephemeral key
-	dhSecret := d.suite.Scalar().Pick(d.suite.RandomStream())
+	dhSecret := d.suite.Scalar().Pick(d.reader)
 	dhPublic := d.suite.Point().Mul(dhSecret, nil)
 	// signs the public key
 	dhPublicBuff, _ := dhPublic.MarshalBinary()