add PassGetHexSubkeyIDsJSON helper for passforios

helper/helper.go

@@ -10,6 +10,9 @@ import (
 	"github.com/ProtonMail/go-crypto/openpgp"
 	"io"
         "bytes"
+	"encoding/json"
+	"fmt"
+	"strconv"
 )
 
 func PassGetEncryptedMPI1(pgpMessage *crypto.PGPMessage) (encryptedMPI1 []byte, err error) {
@@ -55,6 +58,21 @@ Loop1:
 }
 
 
+func PassGetHexSubkeyIDsJSON(key *crypto.Key) []byte {
+	subKeys := key.GetEntity().Subkeys
+	hexSubkeyIDs := make([]string, len(subKeys))
+	for i, subKey := range subKeys {
+		hexSubkeyIDs[i] = fmt.Sprintf("%016v", strconv.FormatUint(subKey.PublicKey.KeyId, 16))
+	}
+
+	result, err := json.Marshal(hexSubkeyIDs)
+	if err != nil {
+		return nil
+	}
+	return result
+}
+
+
 func PassDecryptWithSessionKey(pgpMessage *crypto.PGPMessage, sk *crypto.SessionKey) (plain_message  *crypto.PlainMessage, err error) {
 	var p packet.Packet
 	packets := packet.NewReader(pgpMessage.NewReader())