/**
 * Host-controlled KEK boundary.
 *
 * A BFF normally implements this with Cloud KMS. A native confidential app
 * implements the same boundary with a non-exportable Keychain/Keystore key.
 * The adapter never receives the user's PIN.
 */
export type ServerProfileSealer = Readonly<{
    seal(cleartext: string, aad: string): Promise<string>;
    unseal(ciphertext: string, aad: string): Promise<string>;
}>;
/** Persisted scrypt work factor. The salt and parameters are public metadata. */
export type ProfileScryptParameters = Readonly<{
    name: 'scrypt';
    saltBase64Url: string;
    cost: number;
    blockSize: number;
    parallelization: number;
    keyLength: 32;
}>;
/**
 * Portable v1 envelope for a profile secret.
 *
 * `ciphertext` contains the secret encrypted by a random DEK. The host first
 * wraps that DEK; the PIN-derived key then encrypts the host-wrapped value.
 * Opening therefore requires both factors without exposing either factor to
 * the other adapter.
 */
export type PinProtectedProfileSecret = Readonly<{
    version: 'gdc-pin-host-envelope-v1';
    kdf: ProfileScryptParameters;
    payload: AesGcmCiphertext;
    pinWrappedHostDek: AesGcmCiphertext;
}>;
export type AesGcmCiphertext = Readonly<{
    ivBase64Url: string;
    ciphertextBase64Url: string;
    tagBase64Url: string;
}>;
export type ProfileProtectionOptions = Readonly<{
    cost?: number;
    blockSize?: number;
    parallelization?: number;
}>;
/** Distinguishes a wrong PIN from a host KMS outage or corrupted payload. */
export declare class ProfilePinRejectedError extends Error {
    constructor();
}
/**
 * Encrypt one seed, private-key export or credential using a fresh DEK.
 *
 * The returned salt is intentionally stored in clear. Security comes from the
 * PIN work factor, the independent host KEK and authenticated encryption, not
 * from hiding the salt or algorithm parameters.
 */
export declare function protectServerProfileSecret(cleartext: string, pin: string, aad: string, hostSealer: ServerProfileSealer, options?: ProfileProtectionOptions): Promise<PinProtectedProfileSecret>;
/**
 * Open one protected profile secret using both PIN and host protection.
 *
 * The PIN layer is authenticated before the host adapter is called. A wrong
 * PIN therefore neither reaches KMS nor becomes indistinguishable from a KMS
 * availability failure in audit logs.
 */
export declare function openServerProfileSecret(envelope: PinProtectedProfileSecret, pin: string, aad: string, hostSealer: ServerProfileSealer): Promise<string>;