1/* public domain sha256 implementation based on fips180-3 */
 2
 3#include <stdint.h>
 4struct sha256 {
 5  uint64_t len;     /* processed message length */
 6  uint32_t h[8];    /* hash state */
 7  uint8_t  buf[64]; /* message block buffer */
 8};
 9
10enum { SHA256_DIGEST_LENGTH = 32 };
11
12/* reset state */
13void sha256_init(void *ctx);
14/* process message */
15void sha256_update(void *ctx, const void *m, unsigned long len);
16/* get message digest */
17/* state is ruined after sum, keep a copy if multiple sum is needed */
18/* part of the message might be left in s, zero it if secrecy is needed */
19void sha256_sum(void *ctx, uint8_t md[SHA256_DIGEST_LENGTH]);