Merge pull request #48 from daniel-ac-martin/better-encoding

Allow encoding to be configured

Author: MauriceButler

README.md

@@ -12,6 +12,7 @@ The Cryptr constructor takes 1 required argument, and an optional options object
 
 -   secret: `<string>`
 -   options: `<Object>`
+    -   encoding: `<string>` Defaults to 'hex' (see [Node.js Buffer documentation] for valid options)
     -   pbkdf2Iterations: `<number>` Defaults to 100000
     -   saltLength: `<number>` Defaults to 64
 
@@ -42,11 +43,13 @@ console.log(decryptedString); // bacon
 
 ```javascript
 const Cryptr = require('cryptr');
-const cryptr = new Cryptr('myTotallySecretKey', { pbkdf2Iterations: 10000, saltLength: 10 });
+const cryptr = new Cryptr('myTotallySecretKey', { encoding: 'base64', pbkdf2Iterations: 10000, saltLength: 10 });
 
 const encryptedString = cryptr.encrypt('bacon');
 const decryptedString = cryptr.decrypt(encryptedString);
 
-console.log(encryptedString); // 33b2c319908e72e899db0cad10dd1e24a999cd4922d64c6fbe261020f97ed4fdfe07124268df34bae00ee09f9d91a7
+console.log(encryptedString); // CPbKO/FFLQ8lVKxV+jYJcLcpTU0ZvW3D+JVfUecmJmLYY10UxYEa/wf8PWDQqhw=
 console.log(decryptedString); // bacon
 ```
+
+[Node.js Buffer documentation]: https://nodejs.org/api/buffer.html#buffers-and-character-encodings

index.js

@@ -3,6 +3,7 @@ const crypto = require('crypto');
 const algorithm = 'aes-256-gcm';
 const ivLength = 16;
 const tagLength = 16;
+const defaultEncoding = 'hex';
 const defaultSaltLength = 64;
 const defaultPbkdf2Iterations = 100000;
 
@@ -11,10 +12,15 @@ function Cryptr(secret, options) {
         throw new Error('Cryptr: secret must be a non-0-length string');
     }
 
+    let encoding = defaultEncoding;
     let saltLength = defaultSaltLength;
     let pbkdf2Iterations = defaultPbkdf2Iterations;
 
     if (options) {
+        if (options.encoding) {
+          encoding = options.encoding;
+        }
+
         if (options.pbkdf2Iterations) {
             pbkdf2Iterations = options.pbkdf2Iterations;
         }
@@ -46,15 +52,15 @@ function Cryptr(secret, options) {
 
         const tag = cipher.getAuthTag();
 
-        return Buffer.concat([salt, iv, tag, encrypted]).toString('hex');
+        return Buffer.concat([salt, iv, tag, encrypted]).toString(encoding);
     };
 
     this.decrypt = function decrypt(value) {
         if (value == null) {
             throw new Error('value must not be null or undefined');
         }
 
-        const stringValue = Buffer.from(String(value), 'hex');
+        const stringValue = Buffer.from(String(value), encoding);
 
         const salt = stringValue.subarray(0, saltLength);
         const iv = stringValue.subarray(saltLength, tagPosition);

tests/index.js

@@ -14,6 +14,27 @@ test('works...', (t) => {
     t.equal(decryptedString, testData, 'decrypted aes256 correctly');
 });
 
+test('works with custom encoding', (t) => {
+  t.plan(1);
+
+  const cryptr = new Cryptr(testSecret, { encoding: 'base64' });
+  const encryptedString = cryptr.encrypt(testData);
+  const decryptedString = cryptr.decrypt(encryptedString);
+
+  t.equal(decryptedString, testData, 'decrypted aes256 correctly with custom encoding');
+});
+
+test('custom encoding affects output length', (t) => {
+  t.plan(1);
+
+  const cryptr = new Cryptr(testSecret, { encoding: 'base64' });
+  const cryptr2 = new Cryptr(testSecret);
+  const encryptedString = cryptr.encrypt(testData);
+  const encryptedString2 = cryptr2.encrypt(testData);
+
+  t.ok(encryptedString.length < encryptedString2.length, 'custom encoding was shorter');
+});
+
 test('works with custom pbkdf2Iterations', (t) => {
     t.plan(1);