From e80e3a6cf0a6f07331db4e528044eb389d9fddff Mon Sep 17 00:00:00 2001
From: KKlochko <KKlochko@protonmail.com>
Date: Fri, 27 Oct 2023 21:40:47 +0300
Subject: [PATCH] Add the functions to encrypt and decrypt with the gamma
 cipher.

---
 .../ciphers/gamma.clj                         | 21 +++++++++++++++++++
 .../ciphers/gamma_test.clj                    | 14 +++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/src/cipher_analytical_machine/ciphers/gamma.clj b/src/cipher_analytical_machine/ciphers/gamma.clj
index 4222ff5..c6c0e76 100644
--- a/src/cipher_analytical_machine/ciphers/gamma.clj
+++ b/src/cipher_analytical_machine/ciphers/gamma.clj
@@ -30,3 +30,24 @@
                            (take (inc size)))
                       module))
 
+(defn encrypt-array
+  "Encrypt an array using the gamma cipher. The function is case-insensitive. The key is an array of three elements [a b c]. The array contains integer in range [0, module)."
+  [key module array]
+  (let [size (count array)
+        gamma (->> (apply conj [key module size])
+                   (apply generate-gamma))]
+    (->> gamma
+         (map vector array)
+         (map (fn [[a g]] (add-mod a g module))))))
+
+(defn decrypt-array
+  "Decrypt an array using the gamma cipher. The function is case-insensitive. The key is an array of three elements [a b c]. The array contains integer in range [0, module)."
+  [key module array]
+  (let [size (count array)
+        gamma (->> (apply conj [key module size])
+                   (apply generate-gamma))]
+    (->> gamma
+         (map -)
+         (map vector array)
+         (map (fn [[a g]] (add-mod a g module))))))
+
diff --git a/test/cipher_analytical_machine/ciphers/gamma_test.clj b/test/cipher_analytical_machine/ciphers/gamma_test.clj
index ee034f1..f12757c 100644
--- a/test/cipher_analytical_machine/ciphers/gamma_test.clj
+++ b/test/cipher_analytical_machine/ciphers/gamma_test.clj
@@ -32,3 +32,17 @@
       4 32 15 33 10 [3 14 1 4 18 19 23 8 27 17]
       1 2  3  3  9  [0 2 1 1 0 1 2 2 0])))
 
+(deftest encrypt-array-test
+  (testing "Checking that the message is encrypted as expected: (msg+gamma)%module."
+    (are [key module array expected]
+        (= expected (encrypt-array key module array))
+      [4 32 15] 33 [3 14 1 4 18 19 23 8 27 17] [6 28 2 8 3 5 13 16 21 1]
+      [1 2  3 ] 3  [0 2 1 1 0 1 2 2 0]         [0 1 2 2 0 2 1 1 0])))
+
+(deftest decrypt-array-test
+  (testing "Checking that the message is decrypted as expected."
+    (are [key module array expected]
+        (= expected (decrypt-array key module array))
+      [4 32 15] 33 [6 28 2 8 3 5 13 16 21 1] [3 14 1 4 18 19 23 8 27 17]
+      [1 2  3 ] 3  [0 1 2 2 0 2 1 1 0]       [0 2 1 1 0 1 2 2 0])))
+