export interface SubtleCryptoBackend {
    generateKey(algorithm: RsaHashedKeyGenParams | EcKeyGenParams, extractable: boolean, keyUsages: KeyUsage[]): Promise<CryptoKeyPair>;
    importKey(format: 'jwk', keyData: JsonWebKey, algorithm: AlgorithmIdentifier | RsaHashedImportParams | EcKeyImportParams | HmacImportParams | AesKeyAlgorithm, extractable: boolean, keyUsages: ReadonlyArray<KeyUsage>): Promise<CryptoKey>;
    exportKey(format: Exclude<KeyFormat, 'jwk'>, key: CryptoKey): Promise<Uint8Array>;
    digest(algorithm: AlgorithmIdentifier, data: Uint8Array): Promise<Uint8Array>;
    sign(algorithm: AlgorithmIdentifier | RsaPssParams | EcdsaParams, key: CryptoKey, data: Uint8Array): Promise<Uint8Array>;
    verify(algorithm: AlgorithmIdentifier | RsaPssParams | EcdsaParams, key: CryptoKey, signature: Uint8Array, data: Uint8Array): Promise<boolean>;
    getRandomValues(len: number): Uint8Array;
}
export declare const getDefaultSubtleCryptoBackend: () => SubtleCryptoBackend | null;
export declare function isWindowSubtleCryptoAvailable(): boolean;
export declare class WindowSubtleCryptoBackend implements SubtleCryptoBackend {
    constructor();
    generateKey(algorithm: RsaHashedKeyGenParams | EcKeyGenParams, extractable: boolean, keyUsages: KeyUsage[]): Promise<CryptoKeyPair>;
    importKey(format: 'jwk', keyData: JsonWebKey, algorithm: AlgorithmIdentifier | RsaHashedImportParams | EcKeyImportParams | HmacImportParams | AesKeyAlgorithm, extractable: boolean, keyUsages: ReadonlyArray<KeyUsage>): Promise<CryptoKey>;
    exportKey(format: Exclude<KeyFormat, 'jwk'>, key: CryptoKey): Promise<Uint8Array>;
    digest(algorithm: AlgorithmIdentifier, data: Uint8Array): Promise<Uint8Array>;
    sign(algorithm: AlgorithmIdentifier | RsaPssParams | EcdsaParams, key: CryptoKey, data: Uint8Array): Promise<Uint8Array>;
    verify(algorithm: AlgorithmIdentifier | RsaPssParams | EcdsaParams, key: CryptoKey, signature: Uint8Array, data: Uint8Array): Promise<boolean>;
    getRandomValues(len: number): Uint8Array;
}