Merge pull request #60 from Findeton/master

Add SHA1 HMAC

Author: AJCStriker

package-lock.json

@@ -0,0 +1,24 @@
+import { Digest } from "./Digest"
+/**
+ * A HMAC ( commonly referred to as a Hash ) (hash-based message authentication
+ * code) is a type of message authentication code (MAC) that uses a
+ * cryptographic hash function and a secret key. It may be used to verify data
+ * integrity and authentication of a message.
+ *
+ * Strontium assumes that HMAC functions will run on input that is entirely
+ * in memory. The interface does not currently support calculations against a
+ * stream.
+ *
+ * The exact nature or security properties of a given HMAC implementation
+ * will vary based on the implementing class.
+ */
+export abstract class HMAC extends Digest {
+    /**
+     * Create a new HMAC Encrypter.
+     *
+     * @param secretKey - The shared secret to use for encryption.
+     */
+    constructor(protected secretKey: Buffer) {
+        super()
+    }
+}

src/cryptography/abstract/HMAC.ts

@@ -0,0 +1,18 @@
+import { HMAC } from "../../abstract/HMAC"
+import { createHmac } from "crypto"
+
+/**
+ * The SHA1HMAC provides a HMAC implementation using SHA1 based on Node's
+ * OpenSSL.
+ *
+ * This implementation relies on the node crypto implementation and may vary based
+ * on the build flags of the underlying runtime.
+ */
+export class SHA1HMAC extends HMAC {
+    public async calculate(input: Buffer): Promise<Buffer> {
+        let hmacBuilder = createHmac("sha1", this.secretKey)
+        hmacBuilder.update(input)
+
+        return hmacBuilder.digest()
+    }
+}

src/cryptography/drivers/node/SHA1HMAC.ts

@@ -1,9 +1,11 @@
 export { AsymmetricSigner } from "./abstract/AsymmetricSigner"
 export { Digest } from "./abstract/Digest"
+export { HMAC } from "./abstract/HMAC"
 export { JWTSigner } from "./abstract/JWTSigner"
 export { MessageAuthenticationCode } from "./abstract/MessageAuthenticationCode"
 export { SymmetricEncrypter } from "./abstract/SymmetricEncrypter"
 
 export { AsymmetricJWTSigner } from "./drivers/node/AsymmetricJWTSigner"
 export { RSASHA256Signer } from "./drivers/node/RSASHA256Signer"
 export { SHA256Digest } from "./drivers/node/SHA256Digest"
+export { SHA1HMAC } from "./drivers/node/SHA1HMAC"