Add generate-key cli command

Author: marcqualie

CHANGELOG.md

@@ -9,6 +9,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- CLI: `diffcrypt generate-key` command to generate a new key for a cipher
+
 ### Fixed
 
 - Thor deprecation error no longer shows on CLI failure

lib/diffcrypt/cli.rb

@@ -21,6 +21,12 @@ def encrypt(path)
       puts encryptor.encrypt(contents)
     end
 
+    desc 'generate-key', 'Generate a 32 bit key'
+    method_option :cipher, default: Encryptor::CIPHER
+    def generate_key
+      say Encryptor.generate_key(options[:cipher])
+    end
+
     desc 'version', 'Show client version'
     def version
       say Diffcrypt::VERSION

lib/diffcrypt/encryptor.rb

@@ -14,8 +14,8 @@ module Diffcrypt
   class Encryptor
     CIPHER = 'aes-128-gcm'
 
-    def self.generate_key
-      SecureRandom.hex(ActiveSupport::MessageEncryptor.key_len(CIPHER))
+    def self.generate_key(cipher = CIPHER)
+      SecureRandom.hex(ActiveSupport::MessageEncryptor.key_len(cipher))
     end
 
     def initialize(key)