update node to v16, and upgrade dependencies

.gitignore

@@ -4,3 +4,4 @@ npm-debug.log
 node_modules
 dist
 es
+build

examples/redeemHtlc.js

@@ -24,7 +24,7 @@ Apis.instance("wss://node.testnet.bitshares.eu", true).init_promise.then(
                 // in the backend
 
                 let operationJSON = {
-                    preimage: new Buffer(preimageValue).toString("hex"),
+                    preimage: Buffer.from(preimageValue).toString("hex"),
                     fee: {
                         amount: 0,
                         asset_id: "1.3.0"

lib/chain/src/TransactionBuilder.js

@@ -160,7 +160,7 @@ class TransactionBuilder {
                             ) {
                                 this.ref_block_num =
                                     r[0].head_block_number & 0xffff;
-                                this.ref_block_prefix = new Buffer(
+                                this.ref_block_prefix = Buffer.from(
                                     r[0].head_block_id,
                                     "hex"
                                 ).readUInt32LE(4);
@@ -753,7 +753,7 @@ class TransactionBuilder {
         for (var i = 0; 0 < end ? i < end : i > end; 0 < end ? i++ : i++) {
             var [private_key, public_key] = this.signer_private_keys[i];
             var sig = Signature.signBuffer(
-                Buffer.concat([new Buffer(chain_id, "hex"), this.tr_buffer]),
+                Buffer.concat([Buffer.from(chain_id, "hex"), this.tr_buffer]),
                 private_key,
                 public_key
             );

lib/ecc/src/PrivateKey.js

@@ -164,7 +164,7 @@ class PrivateKey {
     }
 
     static fromHex(hex) {
-        return PrivateKey.fromBuffer(new Buffer(hex, "hex"));
+        return PrivateKey.fromBuffer(Buffer.from(hex, "hex"));
     }
 
     toHex() {

lib/ecc/src/address.js

@@ -26,7 +26,7 @@ class Address {
             `Expecting key to begin with ${address_prefix}, instead got ${prefix}`
         );
         var addy = string.slice(address_prefix.length);
-        addy = new Buffer(decode(addy), "binary");
+        addy = Buffer.from(decode(addy), "binary");
         var checksum = addy.slice(-4);
         addy = addy.slice(0, -4);
         var new_checksum = ripemd160(addy);

lib/ecc/src/aes.js

@@ -75,7 +75,7 @@ class Aes {
             nonce = "";
 
         if (!Buffer.isBuffer(message)) {
-            message = new Buffer(message, "hex");
+            message = Buffer.from(message, "hex");
         }
 
         var S = private_key.get_shared_secret(public_key, legacy);
@@ -130,7 +130,7 @@ class Aes {
             nonce = "";
 
         if (!Buffer.isBuffer(message)) {
-            message = new Buffer(message, "binary");
+            message = Buffer.from(message, "binary");
         }
 
         var S = private_key.get_shared_secret(public_key);
@@ -180,15 +180,15 @@ class Aes {
     */
     decrypt(ciphertext) {
         if (typeof ciphertext === "string") {
-            ciphertext = new Buffer(ciphertext, "binary");
+            ciphertext = Buffer.from(ciphertext, "binary");
         }
         if (!Buffer.isBuffer(ciphertext)) {
             throw new Error("buffer required");
         }
         assert(ciphertext, "Missing cipher text");
         // hex is the only common format
         var hex = this.decryptHex(ciphertext.toString("hex"));
-        return new Buffer(hex, "hex");
+        return Buffer.from(hex, "hex");
     }
 
     /** This method does not use a checksum, the returned data must be validated some other way.
@@ -197,15 +197,15 @@ class Aes {
     */
     encrypt(plaintext) {
         if (typeof plaintext === "string") {
-            plaintext = new Buffer(plaintext, "binary");
+            plaintext = Buffer.from(plaintext, "binary");
         }
         if (!Buffer.isBuffer(plaintext)) {
             throw new Error("buffer required");
         }
         //assert plaintext, "Missing plain text"
         // hex is the only common format
         var hex = this.encryptHex(plaintext.toString("hex"));
-        return new Buffer(hex, "hex");
+        return Buffer.from(hex, "hex");
     }
 
     /** This method does not use a checksum, the returned data must be validated some other way.
@@ -214,7 +214,7 @@ class Aes {
     */
     encryptToHex(plaintext) {
         if (typeof plaintext === "string") {
-            plaintext = new Buffer(plaintext, "binary");
+            plaintext = Buffer.from(plaintext, "binary");
         }
         if (!Buffer.isBuffer(plaintext)) {
             throw new Error("buffer required");
@@ -246,7 +246,7 @@ class Aes {
         var cipher_array = encHex.parse(cipher);
         var plainwords = this._decrypt_word_array(cipher_array);
         var plainhex = encHex.stringify(plainwords);
-        return new Buffer(plainhex, "hex");
+        return Buffer.from(plainhex, "hex");
     }
 
     /** This method does not use a checksum, the returned data must be validated some other way.

lib/ecc/src/ecdsa.js

@@ -29,13 +29,13 @@ function deterministicGenerateK(curve, hash, d, checkSig, nonce) {
     k.fill(0);
 
     // Step D
-    k = HmacSHA256(Buffer.concat([v, new Buffer([0]), x, hash]), k);
+    k = HmacSHA256(Buffer.concat([v, Buffer.from([0]), x, hash]), k);
 
     // Step E
     v = HmacSHA256(v, k);
 
     // Step F
-    k = HmacSHA256(Buffer.concat([v, new Buffer([1]), x, hash]), k);
+    k = HmacSHA256(Buffer.concat([v, Buffer.from([1]), x, hash]), k);
 
     // Step G
     v = HmacSHA256(v, k);
@@ -48,7 +48,7 @@ function deterministicGenerateK(curve, hash, d, checkSig, nonce) {
 
     // Step H3, repeat until T is within the interval [1, n - 1]
     while (T.signum() <= 0 || T.compareTo(curve.n) >= 0 || !checkSig(T)) {
-        k = HmacSHA256(Buffer.concat([v, new Buffer([0])]), k);
+        k = HmacSHA256(Buffer.concat([v, Buffer.from([0])]), k);
         v = HmacSHA256(v, k);
 
         // Step H1/H2a, again, ignored as tlen === qlen (256 bit)