feat: support WebCrypto

Author: AJ ONeal

lib/hdkey.js

@@ -59,7 +59,8 @@ var HDKey = ("object" === typeof module && exports) || {};
   const BUFFER_BE = false;
   const COMPRESSED = true;
 
-  let crypto = require("crypto");
+  //@ts-ignore
+  let Crypto = window.crypto || require("crypto");
   let bs58check = require("bs58check");
 
   let Utils = {};
@@ -88,24 +89,60 @@ var HDKey = ("object" === typeof module && exports) || {};
   };
 
   /** @type {HDHasher} */
-  Utils.ripemd160sum = async function (buf) {
+  Utils.ripemd160sum = async function (bytes) {
     let RIPEMD160 = require("ripemd160");
-    return new RIPEMD160().update(buf).digest();
+    let buf = Buffer.from(bytes);
+    let hash = new RIPEMD160().update(buf).digest();
+    return new Uint8Array(hash);
   };
 
   /** @type {HDHasher} */
-  Utils.sha256sum = async function (buf) {
-    return crypto.createHash("sha256").update(buf).digest();
+  Utils.sha256sum = async function (bytes) {
+    if (!Crypto.subtle) {
+      let sha256 = Crypto.createHash("sha256").update(bytes).digest();
+      return new Uint8Array(sha256);
+    }
+    let arrayBuffer = await Crypto.subtle.digest("SHA-256", bytes);
+    let hashBytes = new Uint8Array(arrayBuffer);
+    return hashBytes;
   };
 
   /** @type {HDHmac} */
   Utils.sha512hmac = async function (entropy, data) {
-    return crypto.createHmac("sha512", entropy).update(data).digest();
+    if (!Crypto.subtle) {
+      let buf = Crypto.createHmac("sha512", entropy).update(data).digest();
+      return new Uint8Array(buf);
+    }
+
+    /** @type {"raw"|"pkcs8"|"spki"} */
+    let format = "raw";
+    let algo = {
+      name: "HMAC",
+      hash: "SHA-512",
+    };
+    let extractable = false;
+    /** @type {Array<KeyUsage>} */
+    let keyUsages = ["sign"];
+    let hmacKey = await Crypto.subtle.importKey(
+      format,
+      entropy,
+      algo,
+      extractable,
+      keyUsages,
+    );
+    let sig = await Crypto.subtle.sign("HMAC", hmacKey, data);
+
+    return new Uint8Array(sig);
   };
 
   /** @type {HDSecureErase} */
   Utils.secureErase = function (buf) {
-    crypto.randomBytes(buf.length).copy(buf);
+    if (!Crypto.getRandomValues) {
+      Crypto.randomBytes(buf.length).copy(buf);
+      return;
+    }
+
+    Crypto.getRandomValues(buf);
   };
 
   /** @type {HDUtilSign} */