add all

envelop/envelop.go

@@ -0,0 +1,104 @@
+package envelop
+
+import (
+	"archive/zip"
+	"encoding/json"
+	"fmt"
+	"io"
+)
+
+type Payload interface {
+	GetHash() []byte
+	GetKey() []byte
+	GetAlgorithm() string
+	GetMode() string
+	GetHashMethod() string
+	GetPayloadData() io.Reader
+}
+
+type Encryptor interface {
+	Encrypt(data []byte) ([]byte, error)
+}
+
+type Signer interface {
+	Sign(data []byte) ([]byte, error)
+}
+
+type Enveloper struct {
+	encryptor    Encryptor
+	payload      Payload
+	signer       Signer
+	EncryptedKey []byte
+	Signature    []byte
+	Metadata     *Metadata
+}
+
+func (this *Enveloper) EncryptKey() ([]byte, error) {
+	return this.encryptor.Encrypt(this.payload.GetKey())
+}
+
+func (this *Enveloper) SignPayload() ([]byte, error) {
+	return this.signer.Sign(this.payload.GetHash())
+}
+
+func (this *Enveloper) CreateMetadata() *Metadata {
+	md := new(Metadata)
+	md.BlockAlgorithm = this.payload.GetAlgorithm()
+	md.BlockMode = this.payload.GetMode()
+	md.SignatureAlgorithm = "RSAPSS"
+	md.HashMethod = this.payload.GetHashMethod()
+	return md
+}
+
+func (this *Enveloper) CreateEnvelopCompletely() error {
+	var err error
+	if this.EncryptedKey, err = this.EncryptKey(); err != nil {
+		return err
+	} else if this.Signature, err = this.SignPayload(); err != nil {
+		return err
+	}
+	this.Metadata = this.CreateMetadata()
+	return nil
+}
+
+func (this *Enveloper) WritePayload(z *zip.Writer) error {
+	dataWriter, err := z.Create("data")
+	if err != nil {
+		return err
+	}
+	_, err = io.Copy(dataWriter, this.payload.GetPayloadData())
+	return err
+}
+
+func (this *Enveloper) WriteMetadata(z *zip.Writer) error {
+	dataWriter, err := z.Create("metadata.json")
+	if err != nil {
+		return err
+	}
+	encoder := json.NewEncoder(dataWriter)
+	return encoder.Encode(this.Metadata)
+}
+
+func (this *Enveloper) WriteEncryptedKey(z *zip.Writer) error {
+	dataWriter, err := z.Create("key.json")
+	if err != nil {
+		return err
+	}
+	encoder := json.NewEncoder(dataWriter)
+	return encoder.Encode(&struct {
+		Key string
+	}{fmt.Sprintf("%s", this.EncryptedKey)})
+}
+
+func (this *Enveloper) WriteToWriter(w io.Writer) error {
+	z := zip.NewWriter(w)
+	defer z.Close()
+	if err := this.WritePayload(z); err != nil {
+		return err
+	} else if err := this.WriteMetadata(z); err != nil {
+		return err
+	} else if err := this.WriteEncryptedKey(z); err != nil {
+		return err
+	}
+	return nil
+}