From f595b7a71ae99e341cf8d833a9ac58c2d9fdc4aa Mon Sep 17 00:00:00 2001
From: Aryansh Bhargavan <aryanshbhargavan@outlook.com>
Date: Thu, 5 Oct 2023 21:10:00 +0530
Subject: [PATCH 1/4] Feat: Added Vignere Cipher

---
 Ciphers/VignereCipher.php           | 57 +++++++++++++++++++++++++++++
 tests/Ciphers/VignereCipherTest.php | 19 ++++++++++
 2 files changed, 76 insertions(+)
 create mode 100644 Ciphers/VignereCipher.php
 create mode 100644 tests/Ciphers/VignereCipherTest.php

diff --git a/Ciphers/VignereCipher.php b/Ciphers/VignereCipher.php
new file mode 100644
index 00000000..1ced1ebc
--- /dev/null
+++ b/Ciphers/VignereCipher.php
@@ -0,0 +1,57 @@
+<?php
+// Function to encrypt plaintext using Vigenère cipher
+function vigenere_encrypt($plaintext, $key) {
+    // Convert the input to uppercase for consistency
+    $plaintext = strtoupper($plaintext);
+    $key = strtoupper($key);
+    
+    $keyLength = strlen($key);
+    $encryptedText = "";
+
+    for ($i = 0; $i < strlen($plaintext); $i++) {
+        $char = $plaintext[$i];
+        if (ctype_alpha($char)) {
+            // Calculate the shift based on the key
+            $shift = ord($key[$i % $keyLength]) - ord('A');
+            
+            // Apply the Vigenère encryption formula
+            $encryptedChar = chr(((ord($char) - ord('A') + $shift) % 26) + ord('A'));
+            
+            // Append the encrypted character to the result
+            $encryptedText .= $encryptedChar;
+        } else {
+            // If the character is not alphabetic, leave it unchanged
+            $encryptedText .= $char;
+        }
+    }
+
+    return $encryptedText;
+}
+
+// Function to decrypt ciphertext using Vigenère cipher
+function vigenere_decrypt($ciphertext, $key) {
+    $ciphertext = strtoupper($ciphertext);
+    $key = strtoupper($key);
+    $keyLength = strlen($key);
+    $decryptedText = "";
+
+    for ($i = 0; $i < strlen($ciphertext); $i++) {
+        $char = $ciphertext[$i];
+        if (ctype_alpha($char)) {
+            // Calculate the shift based on the key
+            $shift = ord($key[$i % $keyLength]) - ord('A');
+            
+            // Apply the Vigenère decryption formula
+            $decryptedChar = chr(((ord($char) - ord('A') - $shift + 26) % 26) + ord('A'));
+            
+            // Append the decrypted character to the result
+            $decryptedText .= $decryptedChar;
+        } else {
+            // If the character is not alphabetic, leave it unchanged
+            $decryptedText .= $char;
+        }
+    }
+
+    return $decryptedText;
+}
+?>
diff --git a/tests/Ciphers/VignereCipherTest.php b/tests/Ciphers/VignereCipherTest.php
new file mode 100644
index 00000000..6c738881
--- /dev/null
+++ b/tests/Ciphers/VignereCipherTest.php
@@ -0,0 +1,19 @@
+<?php
+
+use PHPUnit\Framework\TestCase;
+
+require_once __DIR__ . '/../../vendor/autoload.php';
+require_once __DIR__ . '/../../Ciphers/VignereCipher.php';
+
+class VignereCipher extends TestCase
+{
+    public function testVignereCipher()
+    {
+        $plaintext = "HELLO";
+        $key = "KEY";
+        $encryptedText = vigenere_encrypt($plaintext, $key);
+        $decryptedText = vigenere_decrypt($encryptedText, $key);
+
+        $this->assertEquals($plaintext, $decryptedText);
+    }
+}
\ No newline at end of file

From 1e039d22e5dbfdfb46623bfa7b3beff011f33624 Mon Sep 17 00:00:00 2001
From: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
Date: Thu, 5 Oct 2023 15:40:18 +0000
Subject: [PATCH 2/4] updating DIRECTORY.md

---
 DIRECTORY.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/DIRECTORY.md b/DIRECTORY.md
index 2ee4e28e..a7b80c97 100644
--- a/DIRECTORY.md
+++ b/DIRECTORY.md
@@ -4,6 +4,7 @@
   * [Caesarcipher](./Ciphers/CaesarCipher.php)
   * [Monoalphabeticcipher](./Ciphers/MonoAlphabeticCipher.php)
   * [Morsecode](./Ciphers/MorseCode.php)
+  * [Vignerecipher](./Ciphers/VignereCipher.php)
   * [Xorcipher](./Ciphers/XORCipher.php)
 
 ## Conversions
@@ -89,6 +90,7 @@
     * [Cipherstest](./tests/Ciphers/CiphersTest.php)
     * [Monoalphabeticciphertest](./tests/Ciphers/MonoAlphabeticCipherTest.php)
     * [Morsecodetest](./tests/Ciphers/MorseCodeTest.php)
+    * [Vignereciphertest](./tests/Ciphers/VignereCipherTest.php)
   * Conversions
     * [Conversionstest](./tests/Conversions/ConversionsTest.php)
   * Datastructures

From 240260b21bbfb70f62e8a30a58763e98c2960932 Mon Sep 17 00:00:00 2001
From: Aryansh Bhargavan <aryanshbhargavan@outlook.com>
Date: Fri, 6 Oct 2023 21:48:11 +0530
Subject: [PATCH 3/4] Fix: Changes in formatting?

---
 Ciphers/VignereCipher.php | 38 ++++++++++++++++++++++----------------
 1 file changed, 22 insertions(+), 16 deletions(-)

diff --git a/Ciphers/VignereCipher.php b/Ciphers/VignereCipher.php
index 1ced1ebc..0dd1621f 100644
--- a/Ciphers/VignereCipher.php
+++ b/Ciphers/VignereCipher.php
@@ -1,22 +1,27 @@
 <?php
-// Function to encrypt plaintext using Vigenère cipher
-function vigenere_encrypt($plaintext, $key) {
+
+/**
+ * Encrypts a plaintext using the Vigenère cipher.
+ * (https://en.wikipedia.org/wiki/Vigen%C3%A8re_cipher)
+ *
+ * @param string $plaintext The plaintext to be encrypted.
+ * @param string $key The encryption key.
+ * @return string The encrypted text.
+ */
+function vigenere_encrypt($plaintext, $key)
+{
     // Convert the input to uppercase for consistency
     $plaintext = strtoupper($plaintext);
     $key = strtoupper($key);
-    
     $keyLength = strlen($key);
     $encryptedText = "";
-
     for ($i = 0; $i < strlen($plaintext); $i++) {
         $char = $plaintext[$i];
         if (ctype_alpha($char)) {
             // Calculate the shift based on the key
             $shift = ord($key[$i % $keyLength]) - ord('A');
-            
             // Apply the Vigenère encryption formula
             $encryptedChar = chr(((ord($char) - ord('A') + $shift) % 26) + ord('A'));
-            
             // Append the encrypted character to the result
             $encryptedText .= $encryptedChar;
         } else {
@@ -24,26 +29,29 @@ function vigenere_encrypt($plaintext, $key) {
             $encryptedText .= $char;
         }
     }
-
     return $encryptedText;
 }
 
-// Function to decrypt ciphertext using Vigenère cipher
-function vigenere_decrypt($ciphertext, $key) {
+/**
+ * Decrypts a ciphertext using the Vigenère cipher.
+ *
+ * @param string $ciphertext The ciphertext to be decrypted.
+ * @param string $key The decryption key.
+ * @return string The decrypted text.
+ */
+function vigenere_decrypt($ciphertext, $key)
+{
     $ciphertext = strtoupper($ciphertext);
     $key = strtoupper($key);
     $keyLength = strlen($key);
     $decryptedText = "";
-
-    for ($i = 0; $i < strlen($ciphertext); $i++) {
+    for ($i = 0; $i < strlen($ciphertext); $i++){
         $char = $ciphertext[$i];
         if (ctype_alpha($char)) {
             // Calculate the shift based on the key
             $shift = ord($key[$i % $keyLength]) - ord('A');
-            
             // Apply the Vigenère decryption formula
             $decryptedChar = chr(((ord($char) - ord('A') - $shift + 26) % 26) + ord('A'));
-            
             // Append the decrypted character to the result
             $decryptedText .= $decryptedChar;
         } else {
@@ -51,7 +59,5 @@ function vigenere_decrypt($ciphertext, $key) {
             $decryptedText .= $char;
         }
     }
-
     return $decryptedText;
-}
-?>
+}
\ No newline at end of file

From 831d93b45430cb1082e09dcb8302b6f2cbdaa470 Mon Sep 17 00:00:00 2001
From: Aryansh Bhargavan <aryanshbhargavan@outlook.com>
Date: Fri, 6 Oct 2023 21:51:15 +0530
Subject: [PATCH 4/4] Fix: Changes in formatting?

---
 Ciphers/VignereCipher.php           | 8 ++++----
 tests/Ciphers/VignereCipherTest.php | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/Ciphers/VignereCipher.php b/Ciphers/VignereCipher.php
index 0dd1621f..d3bf1bf2 100644
--- a/Ciphers/VignereCipher.php
+++ b/Ciphers/VignereCipher.php
@@ -8,7 +8,7 @@
  * @param string $key The encryption key.
  * @return string The encrypted text.
  */
-function vigenere_encrypt($plaintext, $key)
+function vigenere_encrypt($plaintext, $key): string
 {
     // Convert the input to uppercase for consistency
     $plaintext = strtoupper($plaintext);
@@ -39,13 +39,13 @@ function vigenere_encrypt($plaintext, $key)
  * @param string $key The decryption key.
  * @return string The decrypted text.
  */
-function vigenere_decrypt($ciphertext, $key)
+function vigenere_decrypt($ciphertext, $key): string
 {
     $ciphertext = strtoupper($ciphertext);
     $key = strtoupper($key);
     $keyLength = strlen($key);
     $decryptedText = "";
-    for ($i = 0; $i < strlen($ciphertext); $i++){
+    for ($i = 0; $i < strlen($ciphertext); $i++) {
         $char = $ciphertext[$i];
         if (ctype_alpha($char)) {
             // Calculate the shift based on the key
@@ -60,4 +60,4 @@ function vigenere_decrypt($ciphertext, $key)
         }
     }
     return $decryptedText;
-}
\ No newline at end of file
+}
diff --git a/tests/Ciphers/VignereCipherTest.php b/tests/Ciphers/VignereCipherTest.php
index 6c738881..37e572b8 100644
--- a/tests/Ciphers/VignereCipherTest.php
+++ b/tests/Ciphers/VignereCipherTest.php
@@ -16,4 +16,4 @@ public function testVignereCipher()
 
         $this->assertEquals($plaintext, $decryptedText);
     }
-}
\ No newline at end of file
+}