export type SignEncodeMethod = 'hex' | 'base64';
export type SignAlgorithm = 'SHA-256' | 'SHA-512';
type KeyType = 'HMAC' | 'RSASSA-PKCS1-v1_5';
/**
 * Determine the key type based on the secret format
 * RSA keys contain "-----BEGIN PRIVATE KEY-----" or "-----BEGIN RSA PRIVATE KEY-----"
 * HMAC keys are plain strings
 */
export declare function getSignKeyType(secret: string): KeyType;
/**
 * Similar to node crypto's `createHash()` function
 */
export declare function hashMessage(message: string, method: SignEncodeMethod, algorithm: SignAlgorithm): Promise<string>;
/**
 * Sign a message, with a secret, using the Web Crypto API
 * Automatically detects key type (HMAC vs RSA) and uses appropriate signing method
 * RSA keys use base64 encoding, HMAC keys use hex encoding (for backwards compatibility)
 */
export declare function signMessage(message: string, secret: string, method?: SignEncodeMethod, algorithm?: SignAlgorithm): Promise<string>;
/**
 * Sign binary data (Buffer/Uint8Array) with a secret, using the Web Crypto API
 * Automatically detects key type (HMAC vs RSA) and uses appropriate signing method
 * RSA keys use base64 encoding, HMAC keys use hex encoding (for backwards compatibility)
 *
 * Note: This function works in both Node.js and browser environments.
 * In Node.js, you can pass a Buffer. In browsers, pass Uint8Array.
 */
export declare function signBinaryData(data: Buffer | Uint8Array, secret: string, method?: SignEncodeMethod, algorithm?: SignAlgorithm): Promise<string>;
export declare function checkWebCryptoAPISupported(): void;
export {};