Optimize encrypt attachment

src/gitlab.com/ProtonMail/go-pm-crypto/armor/armor.go

@@ -4,13 +4,11 @@ import (
 	"bytes"
 	"errors"
 	"gitlab.com/ProtonMail/go-pm-crypto/internal"
-	"gitlab.com/ProtonMail/go-pm-crypto/models"
-	"golang.org/x/crypto/openpgp/armor"
+		"golang.org/x/crypto/openpgp/armor"
 	"golang.org/x/crypto/openpgp/clearsign"
-	"golang.org/x/crypto/openpgp/packet"
-	"io"
 	"io/ioutil"
-)
+	"gitlab.com/ProtonMail/go-pm-crypto/models"
+			)
 
 // ArmorKey make bytes input key to armor format
 func ArmorKey(input []byte) (string, error) {
@@ -50,80 +48,15 @@ func ReadClearSignedMessage(signedMessage string) (string, error) {
 	return string(modulusBlock.Bytes), nil
 }
 
-//SeparateKeyAndData ...
 func SplitArmor(encrypted string) (*models.EncryptedSplit, error) {
-
 	var err error
-
-	encryptedRaw, err := Unarmor(encrypted)
+	b, err := internal.Unarmor(encrypted)
 	if err != nil {
 		return nil, err
 	}
-
-	encryptedReader := bytes.NewReader(encryptedRaw)
-
-	//kr *KeyRing, r io.Reader) (key *SymmetricKey, symEncryptedData []byte,
-	packets := packet.NewReader(encryptedReader)
-
-	outSplit := &models.EncryptedSplit{}
-
-	// Save encrypted key and signature apart
-	var ek *packet.EncryptedKey
-	// var decryptErr error
-	for {
-		var p packet.Packet
-		if p, err = packets.Next(); err == io.EOF {
-			err = nil
-			break
-		}
-		switch p := p.(type) {
-		case *packet.EncryptedKey:
-			// We got an encrypted key. Try to decrypt it with each available key
-			if ek != nil && ek.Key != nil {
-				break
-			}
-			ek = p
-			break
-		case *packet.SymmetricallyEncrypted:
-			var packetContents []byte
-			if packetContents, err = ioutil.ReadAll(p.Contents); err != nil {
-				return nil, err
-			}
-
-			encodedLength := encodedLength(len(packetContents) + 1)
-			var symEncryptedData []byte
-			symEncryptedData = append(symEncryptedData, byte(210))
-			symEncryptedData = append(symEncryptedData, encodedLength...)
-			symEncryptedData = append(symEncryptedData, byte(1))
-			symEncryptedData = append(symEncryptedData, packetContents...)
-
-			outSplit.DataPacket = symEncryptedData
-			break
-
-		}
+	split, err := internal.SplitPackets(b.Body, len(encrypted))
+	if err != nil {
+		return nil, err
 	}
-
-	var buf bytes.Buffer
-	ek.Serialize(&buf)
-	outSplit.KeyPacket = buf.Bytes()
-
-	return outSplit, err
-}
-
-//encode length based on 4.2.2. in the RFC
-func encodedLength(length int) (b []byte) {
-	if length < 192 {
-		b = append(b, byte(length))
-	} else if length < 8384 {
-		length = length - 192
-		b = append(b, 192+byte(length>>8))
-		b = append(b, byte(length))
-	} else {
-		b = append(b, byte(255))
-		b = append(b, byte(length>>24))
-		b = append(b, byte(length>>16))
-		b = append(b, byte(length>>8))
-		b = append(b, byte(length))
-	}
-	return
-}
+	return split, nil
+}