Add ClassMethods

spec/not_spec.cr

@@ -27,4 +27,10 @@ describe Crypto::Secret::Not do
     secret.to_s.should_not match /Bytes|Slice/
     secret.inspect.should_not match /Bytes|Slice/
   end
+
+  it "returns a random secret" do
+    secret1 = Crypto::Secret::Not.new 8
+    secret2 = Crypto::Secret::Not.random 8
+    secret1.should_not eq secret2
+  end
 end

src/crypto-secret/class_methods.cr

@@ -0,0 +1,10 @@
+module Crypto::Secret::ClassMethods
+  # Returns a **readonly** random Secret
+  def random(size)
+    buf = new(size)
+    buf.readwrite do |slice|
+      Random::Secure.random_bytes slice
+    end
+    buf.readonly
+  end
+end

src/crypto-secret/secret.cr

@@ -1,4 +1,5 @@
 require "./lib"
+require "./class_methods"
 
 # Interface to hold sensitive information (often cryptographic keys)
 #

src/crypto-secret/stateful.cr

@@ -12,6 +12,10 @@ module Crypto::Secret
   module Stateful
     include Crypto::Secret
 
+    macro included
+      extend ClassMethods
+    end
+
     @state = State::Readwrite
 
     # Temporarily make buffer readwrite within the block returning to the prior state on exit.

src/crypto-secret/stateless.cr

@@ -6,6 +6,10 @@ require "./secret"
 module Crypto::Secret::Stateless
   include Crypto::Secret
 
+  macro included
+    extend ClassMethods
+  end
+
   # Not thread safe
   def readwrite
   end