From ab00b05342b1e4f5ed1b4d178ffee198c9192b0a Mon Sep 17 00:00:00 2001
From: Grendy Irwandi <grendy50@gmail.com>
Date: Wed, 16 Feb 2022 07:20:30 +0700
Subject: [PATCH] add signature function (#82)

---
 src/index.ts                |  1 +
 src/signature.ts            | 23 +++++++++++++++++++++++
 src/types/encoding.ts       |  1 +
 src/types/index.ts          |  2 ++
 src/types/sign-algorithm.ts |  1 +
 test/Signature.test.ts      |  3 +++
 6 files changed, 31 insertions(+)
 create mode 100644 src/signature.ts
 create mode 100644 src/types/encoding.ts
 create mode 100644 src/types/sign-algorithm.ts
 create mode 100644 test/Signature.test.ts

diff --git a/src/index.ts b/src/index.ts
index a0b457a..89c04e6 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,2 +1,3 @@
 export { AES256Encryption } from './aes256-encryption';
 export { RSAEncryption } from './rsa-encryption';
+export { Signature } from './signature';
diff --git a/src/signature.ts b/src/signature.ts
new file mode 100644
index 0000000..5b0c26a
--- /dev/null
+++ b/src/signature.ts
@@ -0,0 +1,23 @@
+import { createHash } from 'crypto';
+import { Encoding, SignAlgorithm } from './types';
+
+export class Signature {
+  private algorithm: SignAlgorithm;
+  private encoding: Encoding;
+  constructor(algorithm: SignAlgorithm, encoding?: Encoding) {
+    this.algorithm = algorithm;
+    this.encoding = encoding ? encoding : 'base64';
+  }
+
+  generate(data: string) {
+    const hash = createHash(this.algorithm);
+    hash.update(data);
+    const createSignature = hash.digest().toString(this.encoding);
+    return createSignature;
+  }
+
+  verify(data: string, signature: string) {
+    const createSignature = this.generate(data);
+    return createSignature === signature;
+  }
+}
diff --git a/src/types/encoding.ts b/src/types/encoding.ts
new file mode 100644
index 0000000..460219b
--- /dev/null
+++ b/src/types/encoding.ts
@@ -0,0 +1 @@
+export type Encoding = 'base64' | 'hex';
diff --git a/src/types/index.ts b/src/types/index.ts
index cd58673..3e44666 100644
--- a/src/types/index.ts
+++ b/src/types/index.ts
@@ -1,2 +1,4 @@
 export * from './bit-length';
 export * from './cipher-aes256-mode';
+export * from './encoding';
+export * from './sign-algorithm';
diff --git a/src/types/sign-algorithm.ts b/src/types/sign-algorithm.ts
new file mode 100644
index 0000000..0a50727
--- /dev/null
+++ b/src/types/sign-algorithm.ts
@@ -0,0 +1 @@
+export type SignAlgorithm = 'SHA1';
diff --git a/test/Signature.test.ts b/test/Signature.test.ts
new file mode 100644
index 0000000..74ccc24
--- /dev/null
+++ b/test/Signature.test.ts
@@ -0,0 +1,3 @@
+import {Signature} from '../src'
+test('verify signature', () => {
+});
\ No newline at end of file