RosettaCodeData/Task/SHA-256/C/sha-256.c

#include <stdio.h>
#include <string.h>
#include <openssl/sha.h>

int main (void) {
   const char *s = "Rosetta code";
   unsigned char *d = SHA256(s, strlen(s), 0);

   int i;
   for (i = 0; i < SHA256_DIGEST_LENGTH; i++)
      printf("%02x", d[i]);
   putchar('\n');

   return 0;
}