n_sha256.h File Reference

SHA-256 in portable C, fed a piece at a time. More...

#include <stddef.h>
#include <stdint.h>

Include dependency graph for n_sha256.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Data Structures
struct	N_SHA256
	a SHA-256 in progress: plain data, copyable to fork a hash More...

Macros
#define	N_SHA256_HEX_LEN   65
	size of its lowercase hex form, terminator included
#define	N_SHA256_LEN   32
	size in bytes of a SHA-256 digest

Functions
void	n_sha256 (const void *data, size_t len, unsigned char out[32])
	hash one buffer
int	n_sha256_file (const char *path, unsigned char out[32])
	hash a file, read in pieces
void	n_sha256_final (N_SHA256 *ctx, unsigned char out[32])
	finish: the digest, the state left spent
void	n_sha256_hex (const unsigned char digest[32], char out[65])
	a digest as lowercase hex
void	n_sha256_init (N_SHA256 *ctx)
	start a hash
void	n_sha256_update (N_SHA256 *ctx, const void *data, size_t len)
	feed bytes

Detailed Description

SHA-256 in portable C, fed a piece at a time.

FIPS 180-4 SHA-256 with no library behind it, for a program that must check a download or a cache entry without linking OpenSSL (n_digest.h is the OpenSSL one, one call per buffer). The state is fed any number of pieces of any size, so a file of any length is hashed in constant memory; n_sha256_file() does that for a path. Hex output is lowercase, the form published beside downloads.

Author

Castagnier Mickael

Version

1.0

Date

28/09/2026

Definition in file n_sha256.h.