hmac_sha512.h File Reference

HMAC-SHA2-512 (RFC 2104 + FIPS 198-1) - streaming context and one-shot API. More...

#include "crypto/hash/sha512.h"
#include <stddef.h>
#include <stdint.h>

Go to the source code of this file.

Classes
struct	pc_hmac_sha512_ctx
	Streaming HMAC-SHA2-512 context (stores the opad key block + inner hash state). More...

Macros
#define	PC_HMAC_SHA512_LEN   64
	HMAC-SHA2-512 output length in bytes.

Functions
void	pc_hmac_sha512_init (pc_hmac_sha512_ctx *ctx, const uint8_t *key, size_t key_len)
	Begin an HMAC-SHA2-512 over key (keys > 128 bytes are pre-hashed per RFC 2104).
void	pc_hmac_sha512_update (pc_hmac_sha512_ctx *ctx, const uint8_t *data, size_t len)
	Feed len message bytes.
void	pc_hmac_sha512_final (pc_hmac_sha512_ctx *ctx, uint8_t mac[PC_HMAC_SHA512_LEN])
	Finish, writing the 64-byte MAC.
void	pc_hmac_sha512 (const uint8_t *key, size_t key_len, const uint8_t *data, size_t len, uint8_t mac[PC_HMAC_SHA512_LEN])
	One-shot HMAC-SHA2-512 over a single buffer.

Detailed Description

HMAC-SHA2-512 (RFC 2104 + FIPS 198-1) - streaming context and one-shot API.

The shared HMAC-SHA512 primitive. Backs the SSH hmac-sha2-512 / hmac-.nosp@m.sha2.nosp@m.-512-.nosp@m.etm@.nosp@m.opens.nosp@m.sh.c.nosp@m.om integrity algorithms. Built over the pc_sha512 streaming functions (SHA-512 block size 128 bytes). SSH-derived MAC keys are 64 bytes (<= the block size), so the key is zero-padded, not pre-hashed. Pure crypto; the protocol layer that uses it owns the verify-before-act ordering.

Author

Douglas Quigg (dstroy0)

Date

2026

Definition in file hmac_sha512.h.

Macro Definition Documentation

PC_HMAC_SHA512_LEN

#define PC_HMAC_SHA512_LEN   64

HMAC-SHA2-512 output length in bytes.

Definition at line 25 of file hmac_sha512.h.

Function Documentation

pc_hmac_sha512_init()

void pc_hmac_sha512_init	(	pc_hmac_sha512_ctx *	ctx,
		const uint8_t *	key,
		size_t	key_len
	)

Begin an HMAC-SHA2-512 over key (keys > 128 bytes are pre-hashed per RFC 2104).

Definition at line 40 of file hmac_sha512.cpp.

References pc_hmac_sha512_ctx::inner, pc_hmac_sha512_ctx::okey, PC_SHA512_BLOCK_LEN, pc_sha512_init(), and pc_sha512_update().

Referenced by pc_hmac_sha512().

pc_hmac_sha512_update()

void pc_hmac_sha512_update	(	pc_hmac_sha512_ctx *	ctx,
		const uint8_t *	data,
		size_t	len
	)

Feed len message bytes.

Definition at line 49 of file hmac_sha512.cpp.

References pc_hmac_sha512_ctx::inner, and pc_sha512_update().

Referenced by pc_hmac_sha512().

pc_hmac_sha512_final()

void pc_hmac_sha512_final	(	pc_hmac_sha512_ctx *	ctx,
		uint8_t	mac[PC_HMAC_SHA512_LEN]
	)

Finish, writing the 64-byte MAC.

Definition at line 54 of file hmac_sha512.cpp.

References pc_hmac_sha512_ctx::inner, pc_hmac_sha512_ctx::okey, PC_SHA512_BLOCK_LEN, PC_SHA512_DIGEST_LEN, pc_sha512_final(), pc_sha512_init(), and pc_sha512_update().

Referenced by pc_hmac_sha512().

pc_hmac_sha512()

void pc_hmac_sha512	(	const uint8_t *	key,
		size_t	key_len,
		const uint8_t *	data,
		size_t	len,
		uint8_t	mac[PC_HMAC_SHA512_LEN]
	)

One-shot HMAC-SHA2-512 over a single buffer.

Definition at line 65 of file hmac_sha512.cpp.

References pc_hmac_sha512_final(), pc_hmac_sha512_init(), and pc_hmac_sha512_update().