aes

src/crypto/aes.ts

@@ -0,0 +1,167 @@
+import { type TypedArray } from '../utils/base.js'
+import { getCrypto } from './crypto.js'
+import { Base64, Bytes } from './encoding.js'
+import { Hashes } from './hash.js'
+import { getRandomBytes } from './random.js'
+
+const Params = {
+  GCM: {
+    ivLength: 12,
+    tagLength: 128,
+  },
+}
+
+export type IRKeyData = {
+  name: 'PBKDF2'
+  hash: Hashes
+  iterations: number
+  salt: TypedArray
+  length: number
+}
+
+// type IRObject = {
+//   algorithm: string
+//   iv: TypedArray
+//   data: TypedArray
+//   derived?: {
+//     algorithm: 'PBKDF2'
+//     hash: 'SHA1'
+//     iterations: number
+//     salt: TypedArray
+//   }
+// }
+
+// /**
+//  * Intermediate representation of encrypted objects
+//  */
+// class IR {
+//   static delimiter = ':::' // delimiter with a character that is not allowed in base64 or hex
+
+//   // static parse(s: string): IRObject {
+//   //   const [algorithm, iv, data, derived] = s.split(IR.delimiter)
+//   // }
+// }
+
+/**
+ * AES operation modes.
+ */
+export enum Modes {
+  AES_GCM = 'AES-GCM',
+}
+
+export class AES {
+  static Modes = Modes
+
+  private static delimiter = '--' // delimiter with a character that is not allowed in base64 or hex
+  private static delimiterEasy = '---'
+
+  private static InvalidCiphertext = new Error('Invalid ciphertext')
+
+  private static async join(...args: TypedArray[]): Promise<string> {
+    const strings = await Promise.all(args.map(Base64.encode))
+    return strings.join(AES.delimiter)
+  }
+
+  private static async split(ciphertext: string): Promise<TypedArray[]> {
+    const splitted = ciphertext.split(AES.delimiter)
+    return Promise.all(splitted.map(Base64.decode))
+  }
+
+  /**
+   * Derive a key from a password.
+   * To be used if the password is not 128, 192 or 256 bits or human made, non generated keys.
+   */
+  static async derive(key: string, options?: IRKeyData): Promise<[TypedArray, IRKeyData]> {
+    options ??= {
+      name: 'PBKDF2',
+      hash: Hashes.SHA_512,
+      iterations: 100_000,
+      length: 256,
+      salt: await getRandomBytes(16),
+    }
+    const c = await getCrypto()
+    const keyBuffer = await c.subtle.importKey('raw', Bytes.encode(key), options.name, false, [
+      'deriveBits',
+      'deriveKey',
+    ])
+    const bits = await c.subtle.deriveBits(options, keyBuffer, options.length)
+    return [new Uint8Array(bits), options]
+  }
+
+  static async encrypt(data: TypedArray, key: TypedArray, mode: Modes = Modes.AES_GCM): Promise<string> {
+    const c = await getCrypto()
+
+    let iv: Uint8Array
+    let alg: AlgorithmIdentifier
+
+    switch (mode) {
+      case Modes.AES_GCM:
+        iv = c.getRandomValues(new Uint8Array(Params.GCM.ivLength))
+        alg = mode
+        break
+      default:
+        throw new Error('Unsupported mode')
+    }
+
+    const keyObj = await c.subtle.importKey('raw', key, alg, false, ['encrypt'])
+    const encrypted = await c.subtle.encrypt({ name: alg, iv }, keyObj, data)
+    const encryptedBuffer = new Uint8Array(encrypted)
+
+    return AES.join(Bytes.encode(alg), iv, encryptedBuffer)
+  }
+
+  static async decrypt(ciphertext: string, key: TypedArray): Promise<TypedArray> {
+    const c = await getCrypto()
+
+    const [alg, iv, data] = await AES.split(ciphertext)
+    if (!alg || !iv || !data) throw this.InvalidCiphertext
+
+    const mode = Bytes.decode(alg)
+    switch (mode) {
+      case Modes.AES_GCM:
+        break
+      default:
+        throw new Error('Unsupported mode')
+    }
+
+    const keyObj = await c.subtle.importKey('raw', key, mode, false, ['decrypt'])
+    const decrypted = await c.subtle.decrypt({ name: mode, iv }, keyObj, data)
+    return new Uint8Array(decrypted)
+  }
+
+  static async encryptEasy(data: string | TypedArray, key: string, mode: Modes = Modes.AES_GCM): Promise<string> {
+    const dataBuffer = typeof data === 'string' ? Bytes.encode(data) : data
+    const [keyDerived, options] = await AES.derive(key)
+
+    const ciphertext = await this.encrypt(dataBuffer, keyDerived, mode)
+    const header = await this.join(
+      Bytes.encode(options.name),
+      Bytes.encode(options.hash),
+      Bytes.encode(options.iterations.toString()),
+      options.salt,
+      Bytes.encode(options.length.toString())
+    )
+
+    return [header, ciphertext].join(this.delimiterEasy)
+  }
+
+  static async decryptEasy(ciphertext: string, key: string): Promise<string> {
+    const [header, data] = ciphertext.split(this.delimiterEasy)
+    if (!header || !data) throw this.InvalidCiphertext
+    const [name, hash, iterations, salt, length] = await this.split(header)
+    if (!name || !hash || !iterations || !salt || !length) throw this.InvalidCiphertext
+
+    const options: IRKeyData = {
+      name: Bytes.decode(name) as any,
+      hash: Bytes.decode(hash) as any,
+      iterations: parseInt(Bytes.decode(iterations)),
+      salt,
+      length: parseInt(Bytes.decode(length)),
+    }
+    if (isNaN(options.iterations) || isNaN(options.length)) throw this.InvalidCiphertext
+
+    const [keyDerived] = await AES.derive(key, options)
+    const decrypted = await this.decrypt(data, keyDerived)
+    return Bytes.decode(decrypted)
+  }
+}

src/crypto/encoding.ts

@@ -1,24 +1,37 @@
 import { split, type TypedArray } from '../utils/base.js'
 
 export class Base64 {
-  static encode(s: string): string {
-    return split<string>({
-      node() {
+  private static prefix = 'data:application/octet-stream;base64,'
+
+  static encode(s: TypedArray): Promise<string> {
+    return split({
+      async node() {
         return Buffer.from(s).toString('base64')
       },
-      browser() {
-        return btoa(s)
+      async browser() {
+        return new Promise((resolve, reject) => {
+          const reader = new FileReader()
+          reader.onload = function (event) {
+            const data = event.target?.result
+            if (typeof data === 'string') resolve(data.slice(Base64.prefix.length))
+            else reject(new Error('Failed to read file'))
+          }
+          reader.readAsDataURL(new Blob([s]))
+        })
       },
     })
   }
 
-  static decode(s: string): string {
+  static decode(s: string): Promise<TypedArray> {
     return split({
-      node() {
-        return Buffer.from(s, 'base64').toString('utf8')
+      async node() {
+        return Buffer.from(s, 'base64')
       },
-      browser() {
-        return atob(s)
+      async browser() {
+        const ab = await fetch(Base64.prefix + s)
+          .then((r) => r.blob())
+          .then((b) => b.arrayBuffer())
+        return new Uint8Array(ab)
       },
     })
   }

src/crypto/hash.ts

@@ -19,12 +19,14 @@ export enum Hashes {
   SHA_512 = 'SHA-512',
 }
 
-export async function hash(data: string, hash: Hashes): Promise<string>
-export async function hash(data: TypedArray, hash: Hashes): Promise<TypedArray>
-export async function hash(data: string | TypedArray, hash: Hashes): Promise<string | TypedArray> {
-  const isString = typeof data === 'string'
-  const c = await getCrypto()
-  const result = await c.subtle.digest(hash, isString ? Bytes.encode(data) : data)
-  const buf = new Uint8Array(result)
-  return isString ? Hex.encode(buf) : buf
+export class Hash {
+  static async hash(data: string, hash: Hashes): Promise<string>
+  static async hash(data: TypedArray, hash: Hashes): Promise<TypedArray>
+  static async hash(data: string | TypedArray, hash: Hashes): Promise<string | TypedArray> {
+    const isString = typeof data === 'string'
+    const c = await getCrypto()
+    const result = await c.subtle.digest(hash, isString ? Bytes.encode(data) : data)
+    const buf = new Uint8Array(result)
+    return isString ? Hex.encode(buf) : buf
+  }
 }

src/index.ts

@@ -1,4 +1,5 @@
-export { Base64, Bytes, Hex } from './crypto/encoding.js'
-export { hash, Hashes } from './crypto/hash.js'
-export { getRandomBytes } from './crypto/random.js'
-export { TypedArray } from './utils/base.js'
+export * from './crypto/aes.js'
+export * from './crypto/encoding.js'
+export * from './crypto/hash.js'
+export * from './crypto/random.js'
+export * from './utils/base.js'

src/utils/base.ts

@@ -1,6 +1,13 @@
+/**
+ * @internal
+ */
 export const isBrowser = typeof window !== 'undefined'
 
+/**
+ * @internal
+ */
 export type PromiseOrValue<T> = T | Promise<T>
+
 export type TypedArray =
   | Int8Array
   | Uint8Array
@@ -12,6 +19,9 @@ export type TypedArray =
   | BigInt64Array
   | BigUint64Array
 
+/**
+ * @internal
+ */
 export function split<T>({ node, browser }: { node: () => T; browser: () => T }) {
   return isBrowser ? browser() : node()
 }

test/aes.spec.js

@@ -0,0 +1,28 @@
+import { AES, Bytes, Hashes, Hex } from '../dist/esm/index.js'
+import { Precomputed } from './values.js'
+
+describe('AES', () => {
+  it('Basic API', async () => {
+    const message = Precomputed.Crypto.Messages.nietzscheIpsum
+    const data = Bytes.encode(message)
+    const [key] = await AES.derive('foo', {
+      name: 'PBKDF2',
+      hash: Hashes.SHA_512,
+      iterations: 1000,
+      length: 256,
+      salt: Hex.decode(Precomputed.Crypto.Bytes[16]),
+    })
+    const ciphertext = await AES.encrypt(data, key, AES.Modes.GCM)
+    const plaintext = await AES.decrypt(ciphertext, key)
+    chai.expect(data).to.be.deep.equal(plaintext)
+    chai.expect(message).to.be.equal(Bytes.decode(plaintext))
+  })
+
+  it('Easy API', async () => {
+    const message = Precomputed.Crypto.Messages.nietzscheIpsum
+    const password = 'foobar'
+    const encrypted = await AES.encryptEasy(message, password)
+    const decrypted = await AES.decryptEasy(encrypted, password)
+    chai.expect(message).to.be.equal(decrypted)
+  })
+})

test/encoding.spec.js

@@ -1,14 +1,15 @@
-import { Base64 } from '../dist/esm/index.js'
+import { Base64, Bytes } from '../dist/esm/index.js'
 import { Precomputed } from './values.js'
 
 describe('Encoding', () => {
   describe('Base64', () => {
     for (const [input, output] of Object.entries(Precomputed.Encoding.Base64)) {
-      it(`Should encode ${input} to ${output}`, () => {
-        chai.expect(Base64.encode(input)).to.equal(output)
+      const buffer = Bytes.encode(input)
+      it(`Should encode ${input} to ${output}`, async () => {
+        chai.expect(await Base64.encode(buffer)).to.equal(output)
       })
-      it(`Should decode ${output} to ${input}`, () => {
-        chai.expect(Base64.decode(output)).to.equal(input)
+      it(`Should decode ${output} to ${input}`, async () => {
+        chai.expect(await Base64.decode(output)).to.deep.equal(buffer)
       })
     }
   })

test/hash.spec.js

@@ -1,4 +1,4 @@
-import { Bytes, hash, Hashes, Hex } from '../dist/esm/index.js'
+import { Bytes, Hash, Hashes, Hex } from '../dist/esm/index.js'
 import { Precomputed } from './values.js'
 
 describe('Hash', () => {
@@ -7,14 +7,14 @@ describe('Hash', () => {
       const values = Precomputed.Hash[type]
       for (const [input, output] of Object.entries(values)) {
         it(`Should hash "${input}" to "${output.slice(0, 8)}..."`, async () => {
-          const hashed = await hash(input, Hashes[type])
+          const hashed = await Hash.hash(input, Hashes[type])
           chai.expect(hashed).to.equal(output)
         })
 
         it(`Should hash "${input}" to "${output.slice(0, 8)}..." as buffer`, async () => {
           const outputBuffer = Hex.decode(output)
           const inputBuffer = Bytes.encode(input)
-          const hashed = await hash(inputBuffer, Hashes[type])
+          const hashed = await Hash.hash(inputBuffer, Hashes[type])
           chai.expect(hashed).to.deep.equal(outputBuffer)
         })
       }

test/values.js

@@ -30,4 +30,17 @@ export const Precomputed = {
         '9f7ff06148d415b12290ab7c21f021964ed627574f94f66c994aad4a8e319aa3168a9871edace3e736096cbd957cafa42dbf3feb6efd7763bf936ddc933c9470',
     },
   },
+  Crypto: {
+    Bytes: {
+      14: 'e0b28a24252963ff30dd2bb3ec9c',
+      16: '65eeb2044e9eb115956dbf4d0d70cd8f',
+      24: '9fa9e0aace3b0bdcbc871aa3ee3ddb1bece759b811fa4603',
+      32: '848ca08f01f82e28bfa91c85d55ef2a98afd8b32c707c9c790e86b1c53a177e4',
+    },
+    Messages: {
+      test: 'test',
+      nietzscheIpsum:
+        'Marvelous intentions joy deceptions overcome sexuality spirit against. Selfish of marvelous play dead war snare eternal-return ultimate. Reason aversion suicide.',
+    },
+  },
 }