Module kdf 

Key derivation — KdfAlg, KdfCtx, and typed builders.

Phase 6 delivers a low-level EVP_KDF wrapper and three typed builders:

Builder	Algorithm	RFC
HkdfBuilder	HKDF	RFC 5869
Pbkdf2Builder	PBKDF2	PKCS #5
ScryptBuilder	scrypt	RFC 7914

Structs

HkdfBuilder

HKDF key-derivation builder (RFC 5869).

KbkdfBuilder

KBKDF key-derivation builder (NIST SP 800-108).

KdfAlg

An OpenSSL KDF algorithm descriptor (EVP_KDF*).

KdfCtx

A key-derivation context (EVP_KDF_CTX*).

Pbkdf2Builder

PBKDF2 key-derivation builder (PKCS #5).

Pkcs12KdfBuilder

PKCS#12 (RFC 7292 Appendix B) key/IV/MAC derivation builder.

ScryptBuilder

Scrypt key-derivation builder (RFC 7914).

ScryptParams

Scrypt cost parameters.

SshkdfBuilder

SSH key-derivation builder (RFC 4253 §7.2).

Enums

HkdfMode

HKDF extraction/expansion mode.

KbkdfCounterLen

Counter field length (in bits) for KBKDF counter mode.

KbkdfMode

KBKDF derivation mode (SP 800-108).

Pkcs12KdfId

Output type selector for the PKCS#12 (RFC 7292 Appendix B) KDF.

SshkdfKeyType

Purpose codes for SSH key derivation (RFC 4253 §7.2).