diff --git a/javascript/src/iframe/viamapi-iframe.js b/javascript/src/iframe/viamapi-iframe.js
index 234807865524be33eb7748e2c36168940e96c6a1..49aa87d2c1d7dacf24616ba5dd3ac64c7de14f71 100644
--- a/javascript/src/iframe/viamapi-iframe.js
+++ b/javascript/src/iframe/viamapi-iframe.js
@@ -36,15 +36,15 @@ const WopiAPI = require("./wopiapi-iframe");
 const CollaboraAPI = require("./collaboraapi-iframe");
 const ViamAPI = require("../../temp/viamapi");
 
-var identityColors = ["#994392", "#cb0767", "#e51d31", "#ec671b", "#fab610"];
+let identityColors = ["#994392", "#cb0767", "#e51d31", "#ec671b", "#fab610"];
 
 function getNextColor() {
-  var colorIndex = localStorage.getItem("colorIndex");
+  let colorIndex = localStorage.getItem("colorIndex");
   if (colorIndex == null || colorIndex === "") {
     colorIndex = 0;
   }
 
-  var color = identityColors[colorIndex];
+  let color = identityColors[colorIndex];
 
   colorIndex++;
 
@@ -56,7 +56,7 @@ function getNextColor() {
 }
 
 function setKeyForUUID(uuid, key) {
-  var storedIdentityForUuid = localStorage.getItem("keyperuuid/" + uuid);
+  let storedIdentityForUuid = localStorage.getItem("keyperuuid/" + uuid);
   if (
     storedIdentityForUuid !== key &&
     storedIdentityForUuid != null &&
@@ -69,7 +69,7 @@ function setKeyForUUID(uuid, key) {
 }
 
 function getColorForIdentity(key) {
-  var storedColor = localStorage.getItem("colors/" + key);
+  let storedColor = localStorage.getItem("colors/" + key);
 
   if (storedColor == null || storedColor === "") {
     storedColor = getNextColor();
@@ -80,7 +80,7 @@ function getColorForIdentity(key) {
 }
 
 function setIdentityInLocalStorage(identityToStore, extendKey = true) {
-  var pinCode = identityToStore.pinCode;
+  let pinCode = identityToStore.pinCode;
   const serializedIdentity = JSON.stringify(identityToStore);
   const key = identityToStore.authentication.publicKey;
 
@@ -94,7 +94,7 @@ function setIdentityInLocalStorage(identityToStore, extendKey = true) {
 
   return encryptMessage(serializedIdentity, pinCode, "identity").then(
     encryptedIdentity => {
-      var success = true;
+      let success = true;
       if (extendKey === true) {
         success = extendPinCodeTtl(key, pinCode);
       }
@@ -121,7 +121,7 @@ function getProfileData(identity) {
       null
     ).then(executeResult => {
       if (executeResult.code === "200") {
-        var listItem = {};
+        let listItem = {};
 
         listItem.identityColor = getColorForIdentity(
           identity.authentication.publicKey
@@ -168,19 +168,19 @@ async function getIdentityFromLocalStorage(key, pinCode, extendTtl = true) {
 
 function extendPinCodeTtl(key, pinCode) {
   if (pinCode == null || pinCode === "") {
-    var now = new Date();
-    var nowMillis = now.getTime();
-    var ttl = window.sessionStorage.getItem("pincodettls/" + key);
+    let now = new Date();
+    let nowMillis = now.getTime();
+    let ttl = window.sessionStorage.getItem("pincodettls/" + key);
     if (ttl == null || ttl === "" || nowMillis >= parseInt(ttl)) {
       clearPinCodeTtl(key);
       return false;
     } else {
-      var ttl = now.getTime() + 4 * 60 * 60 * 1000;
+      let ttl = now.getTime() + 4 * 60 * 60 * 1000;
       window.sessionStorage.setItem("pincodettls/" + key, ttl);
     }
   } else {
-    var now = new Date();
-    var ttl = now.getTime() + 4 * 60 * 60 * 1000;
+    let now = new Date();
+    let ttl = now.getTime() + 4 * 60 * 60 * 1000;
     window.sessionStorage.setItem("pincodettls/" + key, ttl);
     window.sessionStorage.setItem("pincodes/" + key, pinCode);
   }
@@ -196,9 +196,9 @@ function clearPinCodeTtl(key) {
 }
 
 function getPincode(key) {
-  var now = new Date();
-  var nowMillis = now.getTime();
-  var ttl = window.sessionStorage.getItem("pincodettls/" + key);
+  let now = new Date();
+  let nowMillis = now.getTime();
+  let ttl = window.sessionStorage.getItem("pincodettls/" + key);
   if (ttl == null || ttl === "") {
     return null;
   } else {
@@ -397,13 +397,13 @@ function getCertificateForPassport(passportUUID, internal) {
     }
 
     const passportIdentity = window.currentlyAuthenticatedIdentity;
-    var passport = passportIdentity.getPassport(passportUUID);
+    let passport = passportIdentity.getPassport(passportUUID);
     if (passport === undefined || passport === null) {
       createPassportCertificate(passportUUID).then(function(keys) {
-        var cryptoData = new CryptoData();
+        let cryptoData = new CryptoData();
         cryptoData.setPublicKey(keys["publicKeyPEM"]);
         cryptoData.setPrivateKey(keys["privateKeyPEM"]);
-        var certificate = keys["certificatePEM"];
+        let certificate = keys["certificatePEM"];
         //download("passportCertificateBeforeSigning.crt", "text/plain", certificate)
         //cryptoData.setx509Certificate(keys["certificate"])
         executeRestfulFunction(
@@ -415,17 +415,17 @@ function getCertificateForPassport(passportUUID, internal) {
           passportUUID
         ).then(executeResult => {
           if (executeResult.code === "200") {
-            var signedCertificate = atob(
+            let signedCertificate = atob(
               executeResult.data["SignedCertificate"]
             );
             //download("passportCertificateAfterSigning.crt", "text/plain", signedCertificate)
-            var keyUUID = executeResult.data["CertificateUUID"];
-            var encodedChain = executeResult.data["Chain"];
+            let keyUUID = executeResult.data["CertificateUUID"];
+            let encodedChain = executeResult.data["Chain"];
             //download("rootCertificate.crt", "text/plain", atob(encodedChain[0]))
 
-            var chain = [];
+            let chain = [];
 
-            for (var i = 0; i < encodedChain.length; i++) {
+            for (let i = 0; i < encodedChain.length; i++) {
               chain.push(atob(encodedChain[i]));
             }
 
@@ -469,7 +469,7 @@ function getCertificateForPassport(passportUUID, internal) {
         });
       });
     } else {
-      var copyOfCryptoData = JSON.parse(JSON.stringify(passport));
+      let copyOfCryptoData = JSON.parse(JSON.stringify(passport));
 
       if (internal === false) {
         copyOfCryptoData["privateKey"] = "";
@@ -518,8 +518,8 @@ const connection = Penpal.connectToParent({
     createIdentity(pinCode) {
       return new Penpal.Promise(result => {
         createPassportCertificate(makeid()).then(function(keys) {
-          var newIdentity = new Identity();
-          var cryptoData = new CryptoData();
+          let newIdentity = new Identity();
+          let cryptoData = new CryptoData();
           cryptoData.setPublicKey(keys["publicKeyPEM"]);
           cryptoData.setPrivateKey(keys["privateKeyPEM"]);
           cryptoData.setx509Certificate(keys["certificatePEM"]);
@@ -546,7 +546,7 @@ const connection = Penpal.connectToParent({
     },
     listIdentities() {
       return new Penpal.Promise(result => {
-        var identities = listIdentitiesFromLocalStorage();
+        let identities = listIdentitiesFromLocalStorage();
         result({ data: identities, code: "200", status: "Identities listed" });
       });
     },
@@ -799,7 +799,7 @@ const connection = Penpal.connectToParent({
           });
         }
 
-        var success = extendPinCodeTtl(authenticationPublicKey);
+        let success = extendPinCodeTtl(authenticationPublicKey);
 
         if (success === false) {
           result({
@@ -816,8 +816,8 @@ const connection = Penpal.connectToParent({
           null
         ).then(executeResult => {
           if (executeResult.code === "200") {
-            var actionID = executeResult.data["ActionID"];
-            var QrCode = executeResult.data["QrCode"];
+            let actionID = executeResult.data["ActionID"];
+            let QrCode = executeResult.data["QrCode"];
             QRCode.toDataURL(actionID + "," + QrCode, function(err, url) {
               executeResult.data["image"] = url;
               result(executeResult);
@@ -848,7 +848,7 @@ const connection = Penpal.connectToParent({
           });
         }
 
-        var success = extendPinCodeTtl(authenticationPublicKey);
+        let success = extendPinCodeTtl(authenticationPublicKey);
 
         if (success === false) {
           result({
@@ -936,7 +936,7 @@ const connection = Penpal.connectToParent({
           return { data: "", code: "400", status: "Identity not loaded" };
         }
 
-        var success = extendPinCodeTtl(authenticationPublicKey);
+        let success = extendPinCodeTtl(authenticationPublicKey);
 
         if (success === false) {
           result({
@@ -968,7 +968,7 @@ const connection = Penpal.connectToParent({
           return { data: "", code: "400", status: "Identity not loaded" };
         }
 
-        var success = extendPinCodeTtl(authenticationPublicKey);
+        let success = extendPinCodeTtl(authenticationPublicKey);
 
         if (success === false) {
           result({
@@ -997,7 +997,7 @@ const connection = Penpal.connectToParent({
           return { data: "", code: "400", status: "Identity not loaded" };
         }
 
-        var success = extendPinCodeTtl(authenticationPublicKey);
+        let success = extendPinCodeTtl(authenticationPublicKey);
 
         if (success === false) {
           result({
@@ -1010,10 +1010,10 @@ const connection = Penpal.connectToParent({
         getCertificateForPassport(passportUUID, true).then(
           certificateResult => {
             if (certificateResult.code === "200") {
-              var passportCertificate =
+              let passportCertificate =
                 certificateResult.data["x509Certificate"];
-              var passportPrivateKey = certificateResult.data["privateKey"];
-              var passportChain = certificateResult.data["chain"];
+              let passportPrivateKey = certificateResult.data["privateKey"];
+              let passportChain = certificateResult.data["chain"];
 
               createOneTimePassportCertificate(
                 makeid() + "-" + passportUUID,
@@ -1021,12 +1021,12 @@ const connection = Penpal.connectToParent({
                 passportPrivateKey,
                 passportCertificate
               ).then(function(keys) {
-                var publicKeyOneTime = keys["publicKeyPEM"];
-                var privateKeyOneTime = keys["privateKeyPEM"];
-                var certificateOneTime = keys["certificatePEM"];
+                let publicKeyOneTime = keys["publicKeyPEM"];
+                let privateKeyOneTime = keys["privateKeyPEM"];
+                let certificateOneTime = keys["certificatePEM"];
                 passportChain.push(passportCertificate);
 
-                var oneTimeCryptoData = new CryptoData();
+                let oneTimeCryptoData = new CryptoData();
                 oneTimeCryptoData.setx509Certificate(certificateOneTime);
                 oneTimeCryptoData.setPrivateKey(privateKeyOneTime);
                 oneTimeCryptoData.setPublicKey(publicKeyOneTime);
@@ -1339,7 +1339,7 @@ const connection = Penpal.connectToParent({
           });
         }
 
-        var success = extendPinCodeTtl(authenticationPublicKey);
+        let success = extendPinCodeTtl(authenticationPublicKey);
 
         if (success === false) {
           result({
diff --git a/javascript/src/lib/pdfjs.parser.js b/javascript/src/lib/pdfjs.parser.js
index f65c83832053e058638b1cf770ed0e8f1a1b311e..c0329bd65c119e0c5d875360fd939189c1d0edf1 100644
--- a/javascript/src/lib/pdfjs.parser.js
+++ b/javascript/src/lib/pdfjs.parser.js
@@ -25,7 +25,7 @@
   factory((root.pdfjsSharedGlobal = {}));
   //}
 })(window, function(exports) {
-  var globalScope =
+  let globalScope =
     typeof window !== "undefined"
       ? window
       : typeof global !== "undefined"
@@ -34,7 +34,7 @@
       ? self
       : this;
 
-  var isWorker = typeof window === "undefined";
+  let isWorker = typeof window === "undefined";
 
   // The global PDFJS object exposes the API
   // In production, it will be declared outside a global wrapper
@@ -77,12 +77,12 @@
   factory((root.pdfjsSharedUtil = {}), root.pdfjsSharedGlobal);
   //}
 })(window, function(exports, sharedGlobal) {
-  var PDFJS = sharedGlobal.PDFJS;
-  var globalScope = sharedGlobal.globalScope;
+  let PDFJS = sharedGlobal.PDFJS;
+  let globalScope = sharedGlobal.globalScope;
 
-  var FONT_IDENTITY_MATRIX = [0.001, 0, 0, 0.001, 0, 0];
+  let FONT_IDENTITY_MATRIX = [0.001, 0, 0, 0.001, 0, 0];
 
-  var TextRenderingMode = {
+  let TextRenderingMode = {
     FILL: 0,
     STROKE: 1,
     FILL_STROKE: 2,
@@ -95,13 +95,13 @@
     ADD_TO_PATH_FLAG: 4
   };
 
-  var ImageKind = {
+  let ImageKind = {
     GRAYSCALE_1BPP: 1,
     RGB_24BPP: 2,
     RGBA_32BPP: 3
   };
 
-  var AnnotationType = {
+  let AnnotationType = {
     TEXT: 1,
     LINK: 2,
     FREETEXT: 3,
@@ -130,7 +130,7 @@
     REDACT: 26
   };
 
-  var AnnotationFlag = {
+  let AnnotationFlag = {
     INVISIBLE: 0x01,
     HIDDEN: 0x02,
     PRINT: 0x04,
@@ -143,7 +143,7 @@
     LOCKEDCONTENTS: 0x200
   };
 
-  var AnnotationBorderStyleType = {
+  let AnnotationBorderStyleType = {
     SOLID: 1,
     DASHED: 2,
     BEVELED: 3,
@@ -151,7 +151,7 @@
     UNDERLINE: 5
   };
 
-  var StreamType = {
+  let StreamType = {
     UNKNOWN: 0,
     FLATE: 1,
     LZW: 2,
@@ -164,7 +164,7 @@
     RL: 9
   };
 
-  var FontType = {
+  let FontType = {
     UNKNOWN: 0,
     TYPE1: 1,
     TYPE1C: 2,
@@ -185,7 +185,7 @@
   };
 
   // All the possible operations for an operator list.
-  var OPS = (PDFJS.OPS = {
+  let OPS = (PDFJS.OPS = {
     // Intentionally start from 1 so it is easy to spot bad operators that will be
     // 0's.
     dependency: 1,
@@ -331,7 +331,7 @@
     }
   }
 
-  var UNSUPPORTED_FEATURES = (PDFJS.UNSUPPORTED_FEATURES = {
+  let UNSUPPORTED_FEATURES = (PDFJS.UNSUPPORTED_FEATURES = {
     unknown: "unknown",
     forms: "forms",
     javaScript: "javaScript",
@@ -349,7 +349,7 @@
     if (/^[a-z][a-z0-9+\-.]*:/i.test(url)) {
       return url;
     }
-    var i;
+    let i;
     if (url.charAt(0) === "/") {
       // absolute path
       i = baseUrl.indexOf("://");
@@ -361,12 +361,12 @@
       return baseUrl.substring(0, i) + url;
     } else {
       // relative path
-      var pathLength = baseUrl.length;
+      let pathLength = baseUrl.length;
       i = baseUrl.lastIndexOf("#");
       pathLength = i >= 0 ? i : pathLength;
       i = baseUrl.lastIndexOf("?", pathLength);
       pathLength = i >= 0 ? i : pathLength;
-      var prefixLength = baseUrl.lastIndexOf("/", pathLength);
+      let prefixLength = baseUrl.lastIndexOf("/", pathLength);
       return baseUrl.substring(0, prefixLength + 1) + url;
     }
   }
@@ -378,7 +378,7 @@
     }
     // RFC 3986 (http://tools.ietf.org/html/rfc3986#section-3.1)
     // scheme = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
-    var protocol = /^[a-z][a-z0-9+\-.]*(?=:)/i.exec(url);
+    let protocol = /^[a-z][a-z0-9+\-.]*(?=:)/i.exec(url);
     if (!protocol) {
       return allowRelative;
     }
@@ -407,14 +407,14 @@
   }
   PDFJS.shadow = shadow;
 
-  var LinkTarget = (PDFJS.LinkTarget = {
+  let LinkTarget = (PDFJS.LinkTarget = {
     NONE: 0, // Default value.
     SELF: 1,
     BLANK: 2,
     PARENT: 3,
     TOP: 4
   });
-  var LinkTargetStringMap = ["", "_self", "_blank", "_parent", "_top"];
+  let LinkTargetStringMap = ["", "_self", "_blank", "_parent", "_top"];
 
   function isExternalLinkTargetSet() {
     //#if !MOZCENTRAL
@@ -446,12 +446,12 @@
   }
   PDFJS.isExternalLinkTargetSet = isExternalLinkTargetSet;
 
-  var PasswordResponses = (PDFJS.PasswordResponses = {
+  let PasswordResponses = (PDFJS.PasswordResponses = {
     NEED_PASSWORD: 1,
     INCORRECT_PASSWORD: 2
   });
 
-  var PasswordException = (function PasswordExceptionClosure() {
+  let PasswordException = (function PasswordExceptionClosure() {
     function PasswordException(msg, code) {
       this.name = "PasswordException";
       this.message = msg;
@@ -465,7 +465,7 @@
   })();
   PDFJS.PasswordException = PasswordException;
 
-  var UnknownErrorException = (function UnknownErrorExceptionClosure() {
+  let UnknownErrorException = (function UnknownErrorExceptionClosure() {
     function UnknownErrorException(msg, details) {
       this.name = "UnknownErrorException";
       this.message = msg;
@@ -479,7 +479,7 @@
   })();
   PDFJS.UnknownErrorException = UnknownErrorException;
 
-  var InvalidPDFException = (function InvalidPDFExceptionClosure() {
+  let InvalidPDFException = (function InvalidPDFExceptionClosure() {
     function InvalidPDFException(msg) {
       this.name = "InvalidPDFException";
       this.message = msg;
@@ -492,7 +492,7 @@
   })();
   PDFJS.InvalidPDFException = InvalidPDFException;
 
-  var MissingPDFException = (function MissingPDFExceptionClosure() {
+  let MissingPDFException = (function MissingPDFExceptionClosure() {
     function MissingPDFException(msg) {
       this.name = "MissingPDFException";
       this.message = msg;
@@ -505,7 +505,7 @@
   })();
   PDFJS.MissingPDFException = MissingPDFException;
 
-  var UnexpectedResponseException = (function UnexpectedResponseExceptionClosure() {
+  let UnexpectedResponseException = (function UnexpectedResponseExceptionClosure() {
     function UnexpectedResponseException(msg, status) {
       this.name = "UnexpectedResponseException";
       this.message = msg;
@@ -519,7 +519,7 @@
   })();
   PDFJS.UnexpectedResponseException = UnexpectedResponseException;
 
-  var NotImplementedException = (function NotImplementedExceptionClosure() {
+  let NotImplementedException = (function NotImplementedExceptionClosure() {
     function NotImplementedException(msg) {
       this.message = msg;
     }
@@ -531,7 +531,7 @@
     return NotImplementedException;
   })();
 
-  var MissingDataException = (function MissingDataExceptionClosure() {
+  let MissingDataException = (function MissingDataExceptionClosure() {
     function MissingDataException(begin, end) {
       this.begin = begin;
       this.end = end;
@@ -545,7 +545,7 @@
     return MissingDataException;
   })();
 
-  var XRefParseException = (function XRefParseExceptionClosure() {
+  let XRefParseException = (function XRefParseExceptionClosure() {
     function XRefParseException(msg) {
       this.message = msg;
     }
@@ -562,15 +562,15 @@
       bytes !== null && typeof bytes === "object" && bytes.length !== undefined,
       "Invalid argument for bytesToString"
     );
-    var length = bytes.length;
-    var MAX_ARGUMENT_COUNT = 8192;
+    let length = bytes.length;
+    let MAX_ARGUMENT_COUNT = 8192;
     if (length < MAX_ARGUMENT_COUNT) {
       return String.fromCharCode.apply(null, bytes);
     }
-    var strBuf = [];
-    for (var i = 0; i < length; i += MAX_ARGUMENT_COUNT) {
-      var chunkEnd = Math.min(i + MAX_ARGUMENT_COUNT, length);
-      var chunk = bytes.subarray(i, chunkEnd);
+    let strBuf = [];
+    for (let i = 0; i < length; i += MAX_ARGUMENT_COUNT) {
+      let chunkEnd = Math.min(i + MAX_ARGUMENT_COUNT, length);
+      let chunk = bytes.subarray(i, chunkEnd);
       strBuf.push(String.fromCharCode.apply(null, chunk));
     }
     return strBuf.join("");
@@ -578,9 +578,9 @@
 
   function stringToBytes(str) {
     assert(typeof str === "string", "Invalid argument for stringToBytes");
-    var length = str.length;
-    var bytes = new Uint8Array(length);
-    for (var i = 0; i < length; ++i) {
+    let length = str.length;
+    let bytes = new Uint8Array(length);
+    for (let i = 0; i < length; ++i) {
       bytes[i] = str.charCodeAt(i) & 0xff;
     }
     return bytes;
@@ -596,7 +596,7 @@
   }
 
   function log2(x) {
-    var n = 1,
+    let n = 1,
       i = 0;
     while (x > n) {
       n <<= 1;
@@ -626,9 +626,9 @@
   // Lazy test the endianness of the platform
   // NOTE: This will be 'true' for simulated TypedArrays
   function isLittleEndian() {
-    var buffer8 = new Uint8Array(2);
+    let buffer8 = new Uint8Array(2);
     buffer8[0] = 1;
-    var buffer16 = new Uint16Array(buffer8.buffer);
+    let buffer16 = new Uint16Array(buffer8.buffer);
     return buffer16[0] === 1;
   }
 
@@ -642,10 +642,10 @@
   //#if !(FIREFOX || MOZCENTRAL || CHROME)
   //// Lazy test if the userAgent support CanvasTypedArrays
   function hasCanvasTypedArrays() {
-    var canvas = document.createElement("canvas");
+    let canvas = document.createElement("canvas");
     canvas.width = canvas.height = 1;
-    var ctx = canvas.getContext("2d");
-    var imageData = ctx.createImageData(1, 1);
+    let ctx = canvas.getContext("2d");
+    let imageData = ctx.createImageData(1, 1);
     return typeof imageData.data.buffer !== "undefined";
   }
 
@@ -656,7 +656,7 @@
     }
   });
 
-  var Uint32ArrayView = (function Uint32ArrayViewClosure() {
+  let Uint32ArrayView = (function Uint32ArrayViewClosure() {
     function Uint32ArrayView(buffer, length) {
       this.buffer = buffer;
       this.byteLength = buffer.length;
@@ -665,11 +665,11 @@
     }
     Uint32ArrayView.prototype = Object.create(null);
 
-    var uint32ArrayViewSetters = 0;
+    let uint32ArrayViewSetters = 0;
     function createUint32ArrayProp(index) {
       return {
         get: function() {
-          var buffer = this.buffer,
+          let buffer = this.buffer,
             offset = index << 2;
           return (
             (buffer[offset] |
@@ -680,7 +680,7 @@
           );
         },
         set: function(value) {
-          var buffer = this.buffer,
+          let buffer = this.buffer,
             offset = index << 2;
           buffer[offset] = value & 255;
           buffer[offset + 1] = (value >> 8) & 255;
@@ -709,9 +709,9 @@
   //PDFJS.hasCanvasTypedArrays = true;
   //#endif
 
-  var IDENTITY_MATRIX = [1, 0, 0, 1, 0, 0];
+  let IDENTITY_MATRIX = [1, 0, 0, 1, 0, 0];
 
-  var Util = (PDFJS.Util = (function UtilClosure() {
+  let Util = (PDFJS.Util = (function UtilClosure() {
     function Util() {}
 
     var rgbBuf = ["rgb(", 0, ",", 0, ",", 0, ")"];
diff --git a/javascript/src/utilities/signingUtilities.js b/javascript/src/utilities/signingUtilities.js
index bcaad7ed7e5f7f1b967dfb9498eb262d6245cfd7..27d23e4c4484f13701f2058cc1d4c974d0c507b2 100644
--- a/javascript/src/utilities/signingUtilities.js
+++ b/javascript/src/utilities/signingUtilities.js
@@ -428,7 +428,7 @@ function createCertificate(certData, issuerData = null) {
           let issuerSubjKeyExt = null;
 
           let extLength = issuerData.certificate.extensions.length;
-          for (var i = 0; i < extLength; i++) {
+          for (let i = 0; i < extLength; i++) {
             let ext = issuerData.certificate.extensions[i];
             if (ext.extnID == "2.5.29.14") {
               issuerSubjKeyExt = ext;
@@ -671,7 +671,7 @@ export function createOneTimePassportCertificate(
   privateKeyIssuerArg,
   certicateIssuerArg
 ) {
-  var certData = null;
+  let certData = null;
   if (emailArg != null && emailArg == "") {
     emailArg = null;
   }
@@ -766,7 +766,7 @@ Vereign - Authentic Communication
   const hashAlg = "SHA-256";
   let cmsSignedSimpl;
 
-  var mimeHeadersTitles = [
+  let mimeHeadersTitles = [
     "Content-Type",
     "Content-Transfer-Encoding",
     "Content-ID",
@@ -790,7 +790,7 @@ Vereign - Authentic Communication
     let mimeHeadersStr = mime.substring(0, headersEnd);
 
     let headers = libmime.decodeHeaders(mimeHeadersStr);
-    for (var i = 0; i < mimeHeadersTitles.length; i++) {
+    for (let i = 0; i < mimeHeadersTitles.length; i++) {
       let key = mimeHeadersTitles[i].toLowerCase();
       if (key in headers) {
         mimeHeaders[key] = headers[key];