Extract RSA Keypair generation

app/models/user.rb

@@ -60,20 +60,8 @@ def generate_rsa_pair
   end
 
   # Retrieves a valid RSA::KeyPair for the User's private key
-  def retrieve_private_key
-    # Create the private key from the key stored
-
-    # Retrieve the exponent and modulus from the key string
-    private_key.match /^RSA\.(.*?)\.(.*)$/
-    modulus = Base64::urlsafe_decode64($1)
-    exponent = Base64::urlsafe_decode64($2)
-
-    modulus = modulus.bytes.inject(0) {|num, byte| (num << 8) | byte }
-    exponent = exponent.bytes.inject(0) { |num, byte| (num << 8) | byte }
-
-    # Create the public key instance
-    key = RSA::Key.new(modulus, exponent)
-    keypair = RSA::KeyPair.new(key, nil)
+  def self.to_rsa_key
+    Crypto.make_rsa_key(nil, private_key)
   end
 
   # After a user is created, create the feed and reset the token
@@ -181,7 +169,7 @@ def send_follow_notification to_feed_id
 
     salmon = OStatus::Salmon.from_follow(author.to_atom, f.author.to_atom)
 
-    envelope = salmon.to_xml retrieve_private_key
+    envelope = salmon.to_xml self.to_rsa_key
 
     # Send envelope to Author's Salmon endpoint
     uri = URI.parse(f.author.salmon_url)
@@ -209,7 +197,7 @@ def send_unfollow_notification to_feed_id
 
     salmon = OStatus::Salmon.from_unfollow(author.to_atom, f.author.to_atom)
 
-    envelope = salmon.to_xml retrieve_private_key
+    envelope = salmon.to_xml self.to_rsa_key
 
     # Send envelope to Author's Salmon endpoint
     uri = URI.parse(f.author.salmon_url)
@@ -225,7 +213,7 @@ def send_mention_notification update_id, to_feed_id
     base_uri = "http://#{author.domain}/"
     salmon = OStatus::Salmon.new(u.to_atom(base_uri))
 
-    envelope = salmon.to_xml retrieve_private_key
+    envelope = salmon.to_xml self.to_rsa_key
 
     # Send envelope to Author's Salmon endpoint
     uri = URI.parse(f.author.salmon_url)

lib/crypto.rb

@@ -51,4 +51,20 @@ def self.generate_keypair
 
     keypair
   end
+
+  # We don't yet do anything with the public key, but I added it so that when we
+  # need to, it'll be there.
+  def self.make_rsa_key(public_key, private_key)
+    # Retrieve the exponent and modulus from the key string
+    private_key.match /^RSA\.(.*?)\.(.*)$/
+    modulus = Base64::urlsafe_decode64($1)
+    exponent = Base64::urlsafe_decode64($2)
+
+    modulus = modulus.bytes.inject(0) {|num, byte| (num << 8) | byte }
+    exponent = exponent.bytes.inject(0) { |num, byte| (num << 8) | byte }
+
+    # Create the public key instance
+    key = RSA::Key.new(modulus, exponent)
+    RSA::KeyPair.new(key, nil)
+  end
 end