---

utils/encrypt.ts

@@ -0,0 +1,38 @@
+import { preprocessPlaintext, preprocessKey, expandKey, addRoundKey, subBytes } from './'
+import { mixColumns } from './mixColumns'
+import { shiftRows } from './shiftRows'
+
+export const encrypt = (plaintext: string, key: string): number[][][] => {
+  /**
+   * @param {string} plaintext - The plaintext to encrypt.
+   * @param {string} key - A string of 128, 192, or 256 bits.
+   * @returns {string} The encrypted cyphertext.
+   */
+
+  const plaintextBlocks = preprocessPlaintext(plaintext)
+  const keyBlock = preprocessKey(key)
+  const roundKeys = expandKey(keyBlock)
+
+  const keySize = key.length // Key size in bytes (16 for 128-bit, 24 for 192-bit, 32 for 256-bit)
+  const N_k = keySize / 4 // Number of 32-bit words in the key (4 for 128-bit, 6 for 192-bit, 8 for 256-bit)
+  const N_r = N_k + 6
+
+  const encryptedBlocks: number[][][] = []
+
+  for (let i = 0;i < plaintextBlocks.length;i++) {
+    let state = plaintextBlocks[i]
+    state = addRoundKey(state, roundKeys[0])
+    for (let j = 1;j <= N_r - 1;j++) {
+      state = subBytes(state)
+      state = shiftRows(state)
+      state = mixColumns(state)
+      state = addRoundKey(state, roundKeys[j])
+    }
+    state = subBytes(state)
+    state = shiftRows(state)
+    state = addRoundKey(state, roundKeys[N_r])
+    encryptedBlocks.push(state)
+  }
+  
+  return encryptedBlocks
+}