Add functions to BJJ sign/verify

bjj.go

@@ -0,0 +1,208 @@
+package c_polygonid
+
+import (
+	"context"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+
+	"github.com/iden3/go-iden3-crypto/babyjub"
+)
+
+type BabyJubJubSignPoseidonResponse struct {
+	Signature babyjub.SignatureComp `json:"signature"`
+}
+
+func BabyJubJubSignPoseidon(ctx context.Context, cfg EnvConfig,
+	in []byte) (BabyJubJubSignPoseidonResponse, error) {
+
+	var req struct {
+		PrivKey *JsonBJJPrivateKey `json:"private_key"`
+		Msg     *JsonFieldIntStr   `json:"msg_int"`
+	}
+
+	if in == nil {
+		return BabyJubJubSignPoseidonResponse{}, errors.New("request is empty")
+	}
+
+	err := json.Unmarshal(in, &req)
+	if err != nil {
+		return BabyJubJubSignPoseidonResponse{},
+			fmt.Errorf("failed to unmarshal request: %w", err)
+	}
+
+	if req.PrivKey == nil {
+		return BabyJubJubSignPoseidonResponse{},
+			errors.New("private key is not set")
+	}
+	if req.Msg == nil {
+		return BabyJubJubSignPoseidonResponse{},
+			errors.New("message is not set")
+	}
+
+	sig := req.PrivKey.PrivateKey().SignPoseidon(req.Msg.Int())
+	return BabyJubJubSignPoseidonResponse{
+		Signature: sig.Compress(),
+	}, nil
+}
+
+type BabyJubJubVerifyPoseidonResponse struct {
+	Valid bool `json:"valid"`
+}
+
+func BabyJubJubVerifyPoseidon(_ context.Context, _ EnvConfig,
+	in []byte) (BabyJubJubVerifyPoseidonResponse, error) {
+
+	var req struct {
+		Pub *JsonBJJPublicKey `json:"public_key"`
+		Sig *JsonBJJSignature `json:"signature"`
+		Msg *JsonFieldIntStr  `json:"msg_int"`
+	}
+
+	if in == nil {
+		return BabyJubJubVerifyPoseidonResponse{},
+			errors.New("request is empty")
+	}
+
+	err := json.Unmarshal(in, &req)
+	if err != nil {
+		return BabyJubJubVerifyPoseidonResponse{},
+			fmt.Errorf("failed to unmarshal request: %w", err)
+	}
+
+	if req.Pub == nil {
+		return BabyJubJubVerifyPoseidonResponse{},
+			errors.New("public key is not set")
+	}
+	if req.Msg == nil {
+		return BabyJubJubVerifyPoseidonResponse{},
+			errors.New("message is not set")
+	}
+	if req.Sig == nil {
+		return BabyJubJubVerifyPoseidonResponse{},
+			errors.New("signature is not set")
+	}
+
+	return BabyJubJubVerifyPoseidonResponse{
+		Valid: req.Pub.PublicKey().
+			VerifyPoseidon(req.Msg.Int(), req.Sig.Signature()),
+	}, nil
+}
+
+type BabyJubJubPrivate2PublicResponse struct {
+	PublicKey  string `json:"public_key"`
+	PublicKeyX string `json:"public_key_x_int"`
+	PublicKeyY string `json:"public_key_y_int"`
+}
+
+func BabyJubJubPrivate2Public(_ context.Context, _ EnvConfig,
+	in []byte) (BabyJubJubPrivate2PublicResponse, error) {
+
+	var req struct {
+		PrivKey *JsonBJJPrivateKey `json:"private_key"`
+	}
+
+	if in == nil {
+		return BabyJubJubPrivate2PublicResponse{},
+			errors.New("request is empty")
+	}
+
+	err := json.Unmarshal(in, &req)
+	if err != nil {
+		return BabyJubJubPrivate2PublicResponse{},
+			fmt.Errorf("failed to unmarshal request: %w", err)
+	}
+
+	if req.PrivKey == nil {
+		return BabyJubJubPrivate2PublicResponse{},
+			errors.New("private key is not set")
+	}
+
+	pubKey := req.PrivKey.PrivateKey().Public()
+	compPubKey := pubKey.Compress()
+
+	return BabyJubJubPrivate2PublicResponse{
+		PublicKey:  hex.EncodeToString(compPubKey[:]),
+		PublicKeyX: pubKey.X.Text(10),
+		PublicKeyY: pubKey.Y.Text(10),
+	}, nil
+}
+
+type BabyJubJubPublicUncompressResponse struct {
+	PublicKeyX string `json:"public_key_x_int"`
+	PublicKeyY string `json:"public_key_y_int"`
+}
+
+func BabyJubJubPublicUncompress(_ context.Context, _ EnvConfig,
+	in []byte) (BabyJubJubPublicUncompressResponse, error) {
+
+	var req struct {
+		Pub *JsonBJJPublicKey `json:"public_key"`
+	}
+
+	if in == nil {
+		return BabyJubJubPublicUncompressResponse{},
+			errors.New("request is empty")
+	}
+
+	err := json.Unmarshal(in, &req)
+	if err != nil {
+		return BabyJubJubPublicUncompressResponse{},
+			fmt.Errorf("failed to unmarshal request: %w", err)
+	}
+
+	if req.Pub == nil {
+		return BabyJubJubPublicUncompressResponse{},
+			errors.New("public key is not set")
+	}
+
+	return BabyJubJubPublicUncompressResponse{
+		PublicKeyX: req.Pub.PublicKey().X.Text(10),
+		PublicKeyY: req.Pub.PublicKey().Y.Text(10),
+	}, nil
+}
+
+type BabyJubJubPublicCompressResponse struct {
+	PublicKey string `json:"public_key"`
+}
+
+func BabyJubJubPublicCompress(_ context.Context, _ EnvConfig,
+	in []byte) (BabyJubJubPublicCompressResponse, error) {
+
+	var req struct {
+		PublicKeyX *JsonFieldIntStr `json:"public_key_x_int"`
+		PublicKeyY *JsonFieldIntStr `json:"public_key_y_int"`
+	}
+
+	if in == nil {
+		return BabyJubJubPublicCompressResponse{},
+			errors.New("request is empty")
+	}
+
+	err := json.Unmarshal(in, &req)
+	if err != nil {
+		return BabyJubJubPublicCompressResponse{},
+			fmt.Errorf("failed to unmarshal request: %w", err)
+	}
+
+	if req.PublicKeyX == nil {
+		return BabyJubJubPublicCompressResponse{},
+			errors.New("public key X is not set")
+	}
+
+	if req.PublicKeyY == nil {
+		return BabyJubJubPublicCompressResponse{},
+			errors.New("public key Y is not set")
+	}
+
+	pubKey := babyjub.PublicKey{
+		X: req.PublicKeyX.Int(),
+		Y: req.PublicKeyY.Int(),
+	}
+	compPubKey := pubKey.Compress()
+
+	return BabyJubJubPublicCompressResponse{
+		PublicKey: hex.EncodeToString(compPubKey[:]),
+	}, nil
+}