/**
 * AES-128/192/256 in CBC mode with PKCS7 padding.
 *
 * **WARNING: CBC mode is unauthenticated.** Always authenticate the output
 * with HMAC-SHA256 (Encrypt-then-MAC) or use an authenticated cipher
 * (`XChaCha20Poly1305`, `Seal` with `SerpentCipher`) instead.
 *
 * Holds exclusive access to the `aes` WASM module from construction until
 * `dispose()`. Constructing a second AES-using class while this instance
 * is live throws. Call `dispose()` when done.
 */
export declare class AESCbc {
    private readonly x;
    private _tok;
    constructor(opts?: {
        dangerUnauthenticated: true;
    });
    /**
     * Encrypt plaintext with AES CBC + PKCS7 padding.
     *
     * @param key       16, 24, or 32 bytes (AES-128 / 192 / 256)
     * @param iv        16 bytes, must be random and unique per (key, message)
     * @param plaintext any length, PKCS7 padding applied automatically
     * @returns         ciphertext (length = ceil((plaintext.length + 1) / 16) * 16)
     */
    encrypt(key: Uint8Array, iv: Uint8Array, plaintext: Uint8Array): Uint8Array;
    /**
     * Decrypt AES CBC + PKCS7.
     *
     * All failure modes, empty input, non-multiple-of-16 length, and any
     * PKCS7 validation failure, throw the same generic `RangeError` with
     * message `'invalid ciphertext'`. Padding validation runs branch-free
     * over the last 16 bytes regardless of where the mismatch is, closing
     * the Vaudenay 2002 padding-oracle surface for callers using
     * `{ dangerUnauthenticated: true }` without an outer HMAC.
     */
    decrypt(key: Uint8Array, iv: Uint8Array, ciphertext: Uint8Array): Uint8Array;
    /** Wipe WASM state and release exclusive module access. Idempotent. */
    dispose(): void;
}