From 9877ccf7fe7df38f8ecc65d01e9b46a98528502f Mon Sep 17 00:00:00 2001
From: iximeow <me@iximeow.net>
Date: Wed, 26 Nov 2014 23:17:51 -0800
Subject: Add part of CBC mode

---
 src/utils/CryptoUtils.scala      |  8 ++++++++
 src/utils/FunctionUtils.scala    |  2 ++
 src/utils/TupleUtils.scala       | 10 ++++++++++
 src/utils/crypto/CBCCipher.scala | 21 +++++++++++++++++++++
 test/Set1Spec.scala              |  2 +-
 test/Set2Spec.scala              |  5 +++++
 6 files changed, 47 insertions(+), 1 deletion(-)
 create mode 100644 src/utils/TupleUtils.scala
 create mode 100644 src/utils/crypto/CBCCipher.scala

diff --git a/src/utils/CryptoUtils.scala b/src/utils/CryptoUtils.scala
index 5418895..2b4d38e 100644
--- a/src/utils/CryptoUtils.scala
+++ b/src/utils/CryptoUtils.scala
@@ -1,5 +1,9 @@
 package ixee.cryptopals.utils
 
+import ixee.cryptopals.utils.crypto.CBCCipher
+import javax.crypto.Cipher
+import javax.crypto.spec.SecretKeySpec
+
 object CryptoUtils {
 
   def pkcs7pad(s: String, blockSize: Int) = {
@@ -7,4 +11,8 @@ object CryptoUtils {
     s + s"${padLength.toChar}" * padLength
   }
 
+  def cbcDecryptInstance(ecbCipher: Cipher, key: SecretKeySpec): CBCCipher = {
+    ecbCipher.init(Cipher.DECRYPT_MODE, key)
+    new CBCCipher(ecbCipher)
+  }
 }
diff --git a/src/utils/FunctionUtils.scala b/src/utils/FunctionUtils.scala
index 84c141b..7456898 100644
--- a/src/utils/FunctionUtils.scala
+++ b/src/utils/FunctionUtils.scala
@@ -4,6 +4,8 @@ object FunctionUtils {
   // Because doing (_ f _).tupled confuses the inferencer...
   def tup[A, B, C](f: (A, B) => C): ((A, B)) => C = f.tupled
 
+  def iden[A](x: A) = x
+
   implicit class Compositor[A, B](f: A => B) {
     def :|[C](g: B => C): A => C = f.andThen(g)
   }
diff --git a/src/utils/TupleUtils.scala b/src/utils/TupleUtils.scala
new file mode 100644
index 0000000..2a6dd6c
--- /dev/null
+++ b/src/utils/TupleUtils.scala
@@ -0,0 +1,10 @@
+package ixee.cryptopals.utils
+
+object TupleUtils {
+  implicit class Tuple2[A, B](t: (A, B)) {
+    def mapAll[C, D](_1: A => C = ident, _2: B => D = ident): (C, D) =
+      (_1(t._1), _2(t._2))
+
+    def <-:(f: A => C
+  }
+}
diff --git a/src/utils/crypto/CBCCipher.scala b/src/utils/crypto/CBCCipher.scala
new file mode 100644
index 0000000..e1ece8a
--- /dev/null
+++ b/src/utils/crypto/CBCCipher.scala
@@ -0,0 +1,21 @@
+package ixee.cryptopals.utils.crypto
+
+import javax.crypto.Cipher
+
+class CBCCipher(cipher: Cipher, init: Seq[Byte]) {
+  var state: Seq[Byte] = init
+  var leftover: Seq[Byte] = Seq()
+
+  def enc(data: Seq[Byte]): Seq[Byte] = {
+    (blocks, leftover) = blockized(leftover append data)
+    blocks.map(encBlock).reduce(_ append _)
+  }
+
+  def encBlock(data: Seq[Byte]): Seq[Byte] = {
+    state = cipher.doFinal((data xor state).toArray)
+    state
+  }
+
+  def blockized(data: Seq[Byte])(size: Int): (Seq[Seq[Byte]], Seq[Byte]) =
+    data.splitAt(data.length - (data.length % size))
+}
diff --git a/test/Set1Spec.scala b/test/Set1Spec.scala
index 67eadfc..7230d50 100644
--- a/test/Set1Spec.scala
+++ b/test/Set1Spec.scala
@@ -48,7 +48,7 @@ class Set1Spec extends IxeeSpec {
       }
     }
 
-    "Challenge 5: repeating-key xor" - {
+    "Challenge 5: repeating-key xor" in {
       val sourceText = """|Burning 'em, if you ain't quick and nimble
                           |I go crazy when I hear a cymbal""".stripMargin
 
diff --git a/test/Set2Spec.scala b/test/Set2Spec.scala
index efcb5b0..df25f57 100644
--- a/test/Set2Spec.scala
+++ b/test/Set2Spec.scala
@@ -41,6 +41,11 @@ class Set2Spec extends IxeeSpec {
 
     }
 
+    "Challenge 10: Implement CBC mode" - {
+
+      
+
+    }
   }
 
 }
-- 
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