refactor auth

deps.ts

@@ -1,6 +1,9 @@
 export { decode, encode } from "https://deno.land/[email protected]/encoding/utf8.ts";
 export { format as byteFormat } from "https://deno.land/x/[email protected]/mod.ts";
 export { replaceParams } from "https://deno.land/x/[email protected]/util.ts";
+export { Hash } from "https://deno.land/x/[email protected]/mod.ts";
+export { sha256 } from "https://denopkg.com/chiefbiiko/[email protected]/mod.ts";
+
 export {
   deferred,
   Deferred,

src/auth.ts

@@ -0,0 +1,45 @@
+import { encode, Hash, sha256 } from "../deps.ts";
+
+function xor(a: Uint8Array, b: Uint8Array): Uint8Array {
+  return a.map((byte, index) => {
+    return byte ^ b[index];
+  });
+}
+
+function mysqlNativePassword(password: string, seed: Uint8Array): Uint8Array {
+  const hash = new Hash("sha1");
+  const pwd1 = hash.digest(encode(password)).data;
+  const pwd2 = hash.digest(pwd1).data;
+
+  let seedAndPwd2 = new Uint8Array(seed.length + pwd2.length);
+  seedAndPwd2.set(seed);
+  seedAndPwd2.set(pwd2, seed.length);
+  seedAndPwd2 = hash.digest(seedAndPwd2).data;
+
+  return xor(seedAndPwd2, pwd1);
+}
+
+function cachingSha2Password(password: string, seed: Uint8Array): Uint8Array {
+  const stage1 = sha256(password, "utf8") as Uint8Array;
+  const stage2 = sha256(stage1) as Uint8Array;
+  const stage3 = sha256(Uint8Array.from([...stage2, ...seed])) as Uint8Array;
+  return xor(stage1, stage3);
+}
+
+export default function auth(
+  authPluginName: string,
+  password: string,
+  seed: Uint8Array
+) {
+  switch (authPluginName) {
+    case "mysql_native_password":
+      return mysqlNativePassword(password, seed);
+
+    case "caching_sha2_password":
+    // TODO
+    // return cachingSha2Password(password, seed);
+
+    default:
+      throw new Error("Not supported");
+  }
+}

src/packets/builders/auth.ts

@@ -1,4 +1,4 @@
-import { auth } from "../../auth/mysql_native_password.ts";
+import auth from "../../auth.ts";
 import { BufferWriter } from "../../buffer.ts";
 import ServerCapabilities from "../../constant/capabilities.ts";
 import { Charset } from "../../constant/charset.ts";
@@ -39,7 +39,11 @@ export function buildAuth(
       .skip(23)
       .writeNullTerminatedString(params.username);
     if (params.password) {
-      const authData = auth(params.password, packet.seed);
+      const authData = auth(
+        packet.authPluginName,
+        params.password,
+        packet.seed
+      );
       if (
         clientParam &
           ServerCapabilities.CLIENT_PLUGIN_AUTH_LENENC_CLIENT_DATA ||