refactor: add docs to encryption module

packages/dapp-toolkit/src/modules/wallet-request/encryption/encryption.module.ts

@@ -39,9 +39,14 @@ export const EncryptionModule = () => {
       typedError,
     )
 
-  const combineIVandCipherText = (iv: Buffer, ciphertext: Buffer): Buffer =>
-    Buffer.concat([iv, ciphertext])
-
+  /**
+   * Decrypts data using AES-GCM algorithm
+   *
+   * @param {Buffer} data - payload to be decrypted
+   * @param {Buffer} encryptionKey - key used for decryption
+   * @param {Buffer} iv - initialization vector used when data was encrypted
+   * @returns decrypted data wrapped inside ResultAsync
+   */
   const decrypt = (
     data: Buffer,
     encryptionKey: Buffer,
@@ -51,6 +56,14 @@ export const EncryptionModule = () => {
       cryptoDecrypt(data, cryptoKey, iv),
     )
 
+  /**
+   * Encrypts data using AES-GCM algorithm
+   *
+   * @param {Buffer} data - payload to be encrypted
+   * @param {Buffer} encryptionKey - key used for encryption
+   * @param {Buffer} iv - optional initialization vector
+   * @returns encrypted data wrapped inside ResultAsync
+   */
   const encrypt = (
     data: Buffer,
     encryptionKey: Buffer,
@@ -62,11 +75,15 @@ export const EncryptionModule = () => {
     getKey(encryptionKey)
       .andThen((cryptoKey) => cryptoEncrypt(data, cryptoKey, iv))
       .map((ciphertext) => ({
-        combined: combineIVandCipherText(iv, ciphertext),
+        combined: Buffer.concat([iv, ciphertext]),
         iv,
         ciphertext,
       }))
 
+  /**
+   * Creates 96 bits (12 bytes) initialization vector for AES-GCM encryption
+   * @returns {Buffer} 12 randomly generated bytes
+   */
   const createIV = () => Buffer.from(crypto.getRandomValues(new Uint8Array(12)))
 
   return { encrypt, decrypt, createIV }

packages/dapp-toolkit/src/modules/wallet-request/encryption/helpers/sealbox.ts

@@ -3,26 +3,13 @@ import { Result } from 'neverthrow'
 import { readBuffer } from './buffer-reader'
 
 export type SealedBoxProps = {
-  ciphertext: Buffer
   iv: Buffer
   authTag: Buffer
   combined: Buffer
+  ciphertext: Buffer
   ciphertextAndAuthTag: Buffer
 }
 
-const combineSealboxToBuffer = ({
-  iv,
-  ciphertext,
-  authTag,
-}: Pick<SealedBoxProps, 'iv' | 'ciphertext' | 'authTag'>): Buffer =>
-  Buffer.concat([iv, ciphertext, authTag])
-
-const combineCiphertextAndAuthtag = ({
-  ciphertext,
-  authTag,
-}: Pick<SealedBoxProps, 'ciphertext' | 'authTag'>): Buffer =>
-  Buffer.concat([ciphertext, authTag])
-
 export const transformBufferToSealbox = (
   buffer: Buffer,
 ): Result<SealedBoxProps, Error> => {
@@ -39,10 +26,7 @@ export const transformBufferToSealbox = (
     iv,
     ciphertext,
     authTag,
-    combined: combineSealboxToBuffer({ iv, ciphertext, authTag }),
-    ciphertextAndAuthTag: combineCiphertextAndAuthtag({
-      ciphertext,
-      authTag,
-    }),
+    combined: Buffer.concat([iv, ciphertext, authTag]),
+    ciphertextAndAuthTag: Buffer.concat([ciphertext, authTag]),
   }))
 }