Deno AES-128-CFB8 encryption using OpenSSL and FFI

aes_128_cfb8.ts

const lib = Deno.dlopen(
  Deno.env.get("DENO_SSL_PATH")!,
  {
    AES_set_encrypt_key: {
      parameters: ["buffer", "u32", "buffer"],
      result: "i32",
    },
    AES_cfb8_encrypt: {
      parameters: [
        "buffer",
        "buffer",
        "usize",
        "buffer",
        "buffer",
        "pointer",
        "u32",
      ],
      result: "void",
    },
  } as const,
);

export class Aes128Cfb8 {
  #key = new Uint32Array(60);
  #iv: Uint8Array;

  constructor(key: Uint8Array, iv: Uint8Array) {
    const code = lib.symbols.AES_set_encrypt_key(key, 128, this.#key);
    if (code != 0) throw new Error("Invalid or missing key");
    this.#iv = iv.slice();
  }

  encrypt(buf: Uint8Array) {
    lib.symbols.AES_cfb8_encrypt(
      buf,
      buf,
      buf.length,
      this.#key,
      this.#iv,
      0,
      1,
    );
  }

  decrypt(buf: Uint8Array) {
    lib.symbols.AES_cfb8_encrypt(
      buf,
      buf,
      buf.length,
      this.#key,
      this.#iv,
      0,
      0,
    );
  }
}