/**
 * State Parameter Utilities for CSRF Protection
 *
 * Provides cryptographically secure state parameter generation
 * and constant-time comparison for OAuth CSRF protection.
 */
/**
 * Generate a cryptographically secure state parameter
 *
 * Creates a 32-byte random state parameter for CSRF protection
 * in OAuth flows. This state is stored in the session and must
 * match when the OAuth provider redirects back.
 *
 * @returns Hex-encoded 32-byte random string (64 characters)
 */
export declare function generateState(): string;
/**
 * Validate state parameter using constant-time comparison
 *
 * Compares the provided state with the stored state using a
 * constant-time algorithm to prevent timing attacks.
 *
 * @param provided - State parameter from OAuth provider callback
 * @param stored - State parameter stored in session
 * @returns true if states match, false otherwise
 */
export declare function validateState(provided: string, stored: string): boolean;
/**
 * Generate a session ID for OAuth flow tracking
 *
 * Creates a unique session identifier for correlating OAuth
 * initiation with callback.
 *
 * @returns Hex-encoded random string
 */
export declare function generateSessionId(): string;