From 4339264156536df1466c4d8433592d1e06cf7f54 Mon Sep 17 00:00:00 2001
From: Ryosuke Yamazaki <ryosuke.yamazaki@mac.com>
Date: Fri, 16 Dec 2011 17:03:07 +0900
Subject: cleanup.

---
 lib/net/ssh/transport/cipher_factory.rb | 24 +++---------------------
 lib/net/ssh/transport/hmac.rb           | 25 ++-----------------------
 lib/net/ssh/transport/key_expander.rb   | 26 ++++++++++++++++++++++++++
 3 files changed, 31 insertions(+), 44 deletions(-)
 create mode 100644 lib/net/ssh/transport/key_expander.rb

(limited to 'lib')

diff --git a/lib/net/ssh/transport/cipher_factory.rb b/lib/net/ssh/transport/cipher_factory.rb
index ae57f2c..4a07aa2 100644
--- a/lib/net/ssh/transport/cipher_factory.rb
+++ b/lib/net/ssh/transport/cipher_factory.rb
@@ -1,4 +1,5 @@
 require 'openssl'
+require 'net/ssh/transport/key_expander'
 require 'net/ssh/transport/identity_cipher'
 
 module Net; module SSH; module Transport
@@ -50,10 +51,10 @@ module Net; module SSH; module Transport
       cipher.send(options[:encrypt] ? :encrypt : :decrypt)
 
       cipher.padding = 0
-      cipher.iv      = make_key(cipher.iv_len, options[:iv], options) if ossl_name != "rc4"
+      cipher.iv      = Net::SSH::Transport::KeyExpander.expand_key(cipher.iv_len, options[:iv], options) if ossl_name != "rc4"
       key_len = KEY_LEN_OVERRIDE[name] || cipher.key_len
       cipher.key_len = key_len
-      cipher.key     = make_key(key_len, options[:key], options)
+      cipher.key     = Net::SSH::Transport::KeyExpander.expand_key(key_len, options[:key], options)
       cipher.update(" " * 1536) if ossl_name == "rc4"
 
       return cipher
@@ -73,25 +74,6 @@ module Net; module SSH; module Transport
       
       return [key_len, ossl_name=="rc4" ? 8 : cipher.block_size]
     end
-
-    private
-
-      # Generate a key value in accordance with the SSH2 specification.
-      def self.make_key(bytes, start, options={})
-        k = start[0, bytes]
-        
-        digester = options[:digester] or raise 'No digester supplied'
-        shared   = options[:shared] or raise 'No shared secret supplied'
-        hash     = options[:hash] or raise 'No hash supplied'
-
-        while k.length < bytes
-          step = digester.digest(shared + hash + k)
-          bytes_needed = bytes - k.length
-          k << step[0, bytes_needed]
-        end
-
-        return k
-      end
   end
 
 end; end; end
diff --git a/lib/net/ssh/transport/hmac.rb b/lib/net/ssh/transport/hmac.rb
index 1a2173d..8452046 100644
--- a/lib/net/ssh/transport/hmac.rb
+++ b/lib/net/ssh/transport/hmac.rb
@@ -1,3 +1,4 @@
+require 'net/ssh/transport/key_expander'
 require 'net/ssh/transport/hmac/md5'
 require 'net/ssh/transport/hmac/md5_96'
 require 'net/ssh/transport/hmac/sha1'
@@ -30,7 +31,7 @@ module Net::SSH::Transport::HMAC
   # given, the new instance will be initialized with that key.
   def self.get(name, key="", parameters = {})
     impl = MAP[name] or raise ArgumentError, "hmac not found: #{name.inspect}"
-    impl.new(make_key(impl.key_length, key, parameters))
+    impl.new(Net::SSH::Transport::KeyExpander.expand_key(impl.key_length, key, parameters))
   end
 
   # Retrieves the key length for the hmac of the given SSH type (+name+).
@@ -38,26 +39,4 @@ module Net::SSH::Transport::HMAC
     impl = MAP[name] or raise ArgumentError, "hmac not found: #{name.inspect}"
     impl.key_length
   end
-
-  # XXX copied
-  # Generate a key value in accordance with the SSH2 specification.
-  def self.make_key(bytes, start, options={})
-    if bytes == 0
-      return ""
-    end
-
-    k = start[0, bytes]
-
-    digester = options[:digester] or raise 'No digester supplied'
-    shared   = options[:shared] or raise 'No shared secret supplied'
-    hash     = options[:hash] or raise 'No hash supplied'
-
-    while k.length < bytes
-      step = digester.digest(shared + hash + k)
-      bytes_needed = bytes - k.length
-      k << step[0, bytes_needed]
-    end
-
-    return k
-  end
 end
diff --git a/lib/net/ssh/transport/key_expander.rb b/lib/net/ssh/transport/key_expander.rb
new file mode 100644
index 0000000..86e608d
--- /dev/null
+++ b/lib/net/ssh/transport/key_expander.rb
@@ -0,0 +1,26 @@
+module Net; module SSH; module Transport
+  module KeyExpander
+
+  # Generate a key value in accordance with the SSH2 specification.
+  # (RFC4253 7.2. "Output from Key Exchange")
+  def self.expand_key(bytes, start, options={})
+    if bytes == 0
+      return ""
+    end
+
+    k = start[0, bytes]
+
+    digester = options[:digester] or raise 'No digester supplied'
+    shared   = options[:shared] or raise 'No shared secret supplied'
+    hash     = options[:hash] or raise 'No hash supplied'
+
+    while k.length < bytes
+      step = digester.digest(shared + hash + k)
+      bytes_needed = bytes - k.length
+      k << step[0, bytes_needed]
+    end
+
+    return k
+  end
+end
+end; end; end
-- 
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