//! Key Derivation Functions
//!
//! Provides KDFs for deriving keys from secrets following NIST standards.
//!
//! ## Supported Algorithms
//!
//! - **HKDF-SHA256**: HMAC-based Extract-and-Expand Key Derivation (NIST SP 800-56C)
//! - **PBKDF2**: Password-Based Key Derivation Function 2 (NIST SP 800-132)
//! - **SP 800-108 Counter KDF**: Counter-based Key Derivation (NIST SP 800-108)
pub use *;
pub use *;
pub use *;
/// Fill a byte slice with cryptographically secure random bytes.
pub