Splited encoding per object type, added public methods for serialization

bson/encoding_thresholdpublickey.go

@@ -0,0 +1,95 @@
+// Package bson provides functions for serialization and deserialization between
+// paillier objects and BSON
+package bson
+
+import (
+	"errors"
+	"fmt"
+	"math/big"
+
+	"github.com/keep-network/paillier"
+	"gopkg.in/mgo.v2/bson"
+)
+
+type ThresholdPublicKey paillier.ThresholdPublicKey
+
+// Serializes ThresholdPublicKey to BSON
+func SerializeThresholdPublicKey(key *paillier.ThresholdPublicKey) ([]byte, error) {
+	return bson.Marshal(toSerializableThresholdPublicKey(key))
+}
+
+// Deserializes BSON to ThresholdPublicKey
+func DeserializeThresholdPublicKey(data []byte) (*paillier.ThresholdPublicKey, error) {
+	serializable := new(ThresholdPublicKey)
+	if err := bson.Unmarshal(data, serializable); err != nil {
+		return nil, err
+	}
+
+	return toOriginalThresholdPublicKey(serializable), nil
+}
+
+// Changes original ThresholdPublicKey to serializable ThresholdPublicKey
+func toSerializableThresholdPublicKey(key *paillier.ThresholdPublicKey) *ThresholdPublicKey {
+	serializable := ThresholdPublicKey(*key)
+	return &serializable
+}
+
+// Changes serializable ThresholdPublicKey to original ThresholdPublicKey
+func toOriginalThresholdPublicKey(serializable *ThresholdPublicKey) *paillier.ThresholdPublicKey {
+	original := paillier.ThresholdPublicKey(*serializable)
+	return &original
+}
+
+func (thresholdPublicKey *ThresholdPublicKey) GetBSON() (interface{}, error) {
+	r := new(dbThresholdKey)
+	r.fromThresholdPublicKey(thresholdPublicKey)
+	return r, nil
+}
+
+func (thresholdPublicKey *ThresholdPublicKey) SetBSON(raw bson.Raw) error {
+	r := new(dbThresholdKey)
+	if err := raw.Unmarshal(r); err != nil {
+		return err
+	}
+	return r.toThresholdPublicKey(thresholdPublicKey)
+}
+
+type dbThresholdKey struct {
+	TotalNumberOfDecryptionServers int
+	Threshold                      int
+	V                              string
+	Vi                             []string
+	N                              string
+}
+
+func (dbThresholdKey *dbThresholdKey) fromThresholdPublicKey(key *ThresholdPublicKey) {
+	dbThresholdKey.TotalNumberOfDecryptionServers = key.TotalNumberOfDecryptionServers
+	dbThresholdKey.Threshold = key.Threshold
+	dbThresholdKey.V = fmt.Sprintf("%x", key.V)
+	dbThresholdKey.N = fmt.Sprintf("%x", key.N)
+	dbThresholdKey.Vi = make([]string, len(key.Vi))
+	for i, vi := range key.Vi {
+		dbThresholdKey.Vi[i] = fmt.Sprintf("%x", vi)
+	}
+}
+
+func (dbThresholdKey *dbThresholdKey) toThresholdPublicKey(key *ThresholdPublicKey) error {
+	key.TotalNumberOfDecryptionServers = dbThresholdKey.TotalNumberOfDecryptionServers
+	key.Threshold = dbThresholdKey.Threshold
+	oks := make([]bool, 2)
+	key.V, oks[0] = new(big.Int).SetString(dbThresholdKey.V, 16)
+	key.N, oks[1] = new(big.Int).SetString(dbThresholdKey.N, 16)
+	if !all(oks) {
+		return errors.New("not hexadecimal")
+	}
+	key.Vi = make([]*big.Int, len(dbThresholdKey.Vi))
+	var ok bool
+	for i, vi := range dbThresholdKey.Vi {
+		key.Vi[i], ok = new(big.Int).SetString(vi, 16)
+		if !ok {
+			return errors.New("not hexadecimal")
+		}
+
+	}
+	return nil
+}