add compute,sign and verify qr code

src/services/QrCodeDataService.ts

@@ -13,6 +13,7 @@ import {
 import CloudflareService from "./CloudflareService";
 import CryptoServiceDefault from "./CryptoService";
 import { ICryptoService } from "./CryptoService/ICryptoService";
+import { CryptoService } from "../index";
 
 const EmailDataMessageV1 = vereign.protobuf.qrcode_data.EmailData_V1;
 const KeyDataMessageV1 = vereign.protobuf.qrcode_data.KeyData_V1;
@@ -109,6 +110,70 @@ const assembleQrCodeData = (
   return Buffer.concat([Buffer.from(head), Buffer.from(tail)]);
 };
 
+const computeQrCodeHash = async (emailData: MessageData): Promise<string> => {
+  const attachments = emailData.attachments.map((attachment) => {
+    //TODO: check if we can use attachment hash, attachment hashAlg
+    if (attachment.url) {
+      return {
+        name: attachment.name,
+        size: attachment.size,
+        url: attachment.url,
+      };
+    }
+
+    return {
+      name: attachment.name,
+      size: attachment.size,
+    };
+  });
+
+  const dataForHashing = {
+    statusId: emailData.statusId,
+    sender: emailData.sender,
+    subject: emailData.subject,
+    date: emailData.date,
+    recipients: emailData.recipients,
+    attachments,
+  };
+
+  const promises = Object.values(dataForHashing).map(async (value) => {
+    const base64 = Buffer.from(JSON.stringify(value)).toString("base64");
+    return CryptoService.SHA256(base64);
+  });
+
+  const hashArray = await Promise.all(promises);
+
+  return hashArray.sort().join("\n");
+};
+
+const calculateQRCodeSignature = async (
+  accountPrivateKey: string,
+  qrCodeHash: string
+): Promise<string> => {
+  const signature = await CryptoService.signRSA(
+    accountPrivateKey,
+    Buffer.from(qrCodeHash)
+  );
+
+  return arrayBufferToBase64(signature);
+};
+
+const verifyQrCodeSignature = async (
+  publicKey: string,
+  qrCodeSignature: string,
+  recipientQRCodeHash: string
+): Promise<boolean> => {
+  const qrCodeSignatureAsBuffer = base64ToArrayBuffer(qrCodeSignature);
+  const recipientQRCodeHashAsBuffer = Buffer.from(recipientQRCodeHash);
+  const result = await CryptoService.verifyRSASignature(
+    publicKey,
+    recipientQRCodeHashAsBuffer,
+    qrCodeSignatureAsBuffer
+  );
+
+  return result;
+};
+
 interface WithServices {
   getMessageDataFromBase64: (base64: string) => Promise<MessageData>;
 }
@@ -198,5 +263,8 @@ export default {
   decodeKeyDataPair,
   breakQrCodeData,
   assembleQrCodeData,
+  computeQrCodeHash,
+  calculateQRCodeSignature,
+  verifyQrCodeSignature,
   withServices,
 };