C言語でsha1を計算する

	SHA_CTX c;
	SHA1_Init(&c);
	SHA1_Update(&c,buf,(unsigned long)i);
	SHA1_Final(&(md[0]),&c);

gcc -lmd sha1.c

gcc -lssl sha1.c

/* crypto/sha/sha1.c */
#include <stdio.h>
#include <stdlib.h>
#include <openssl/sha.h>

#define BUFSIZE	1024*16

void do_fp(FILE *f);
void pt(unsigned char *md);
#ifndef _OSD_POSIX
int read(int, void *, unsigned int);
#endif

int main(int argc, char **argv)
{
	int i,err=0;
	FILE *IN;

	if (argc == 1)
	{
		do_fp(stdin);
	}
	else
	{
		for (i=1; i<argc; i++)
		{
			IN=fopen(argv[i],"r");
			if (IN == NULL)
			{
				perror(argv[i]);
				err++;
				continue;
			}
			printf("SHA1(%s)= ",argv[i]);
			do_fp(IN);
			fclose(IN);
		}
	}
	exit(err);
}

void do_fp(FILE *f)
{
	SHA_CTX c;
	unsigned char md[SHA_DIGEST_LENGTH];
	int fd;
	int i;
	unsigned char buf[BUFSIZE];

	fd=fileno(f);
	SHA1_Init(&c);
	for (;;)
	{
		i=read(fd,buf,BUFSIZE);
		if (i <= 0) break;
		SHA1_Update(&c,buf,(unsigned long)i);
	}
	SHA1_Final(&(md[0]),&c);
	pt(md);
}

void pt(unsigned char *md)
{
	int i;

	for (i=0; i<SHA_DIGEST_LENGTH; i++)
		printf("%02x",md[i]);
	printf("\n");
}