/**
 * Generates an ECDSA key pair using the SubtleCrypto API.
 * @returns {Promise<{ publicKey: string, privateKey: string }>} The public and private keys in Base64 encoding.
 * - The private key is encoded in PKCS#8 format.
 * - The public key is encoded in SPKI format.
 * - Both keys are compatible with the P-256 elliptic curve.
 */
export function generateKeyPair(): Promise<{
    publicKey: string;
    privateKey: string;
}>;
/**
 * Signs the provided parameters using the given ECDSA private key.
 * @param {object} params - The parameters to sign.
 * @param {string} privateKeyBase64 - The private key in Base64 encoding (P-256 curve).
 * @returns {Promise<string>} The generated signature in hexadecimal format.
 */
export function signParams(params: object, privateKeyBase64: string): Promise<string>;
/**
 * Generates a signed URL with the given base URL, parameters, and private key.
 * @param {string} baseUrl - The base URL to append the parameters and signature.
 * @param {object} params - The parameters to include in the query string.
 * @param {string} privateKey - The private key to sign the parameters (Base64 encoded).
 * @returns {Promise<string>} The signed URL.
 */
export function generateSignedLink(baseUrl: string, params: object, privateKey: string): Promise<string>;
/**
 * Saves a key to a file with specified options.
 * @param {string} filePath - The file path where the key will be saved.
 * @param {string} key - The Base64-encoded key content to save.
 * @param {object} options - Options for file saving (e.g., file permissions).
 * - For private keys, it's recommended to use mode 0o600 for security.
 */
export function saveKeyToFile(filePath: string, key: string, options: object): Promise<void>;