/*	MDEMO.C - MD2/MD4/MD5 Hash Demo Application.	Copyright (c) J.S.A.Kapp 1994.	RSAEURO - RSA Library compatible with RSAREF(tm) 2.0.	This is a Demo program, which is part of RSAEURO	Uses, rsaeuro.h also requires link with rsaeuro	library file.	This file is use to demonstrate the process of	programming with RSAEURO.	Requires RSAEURO.*/#include <stdio.h>#include <stdlib.h>/* This includes are used for obtaining and displaying the last modified	 time for the file. */#include <time.h>#include <sys/types.h>#include <sys/stat.h>#include "rsaeuro.h"    /* include rsaeuro function header file */#define SIZE 1024000static void printdigest PROTO_LIST((char *out, unsigned int len));void main(int argc, char *argv[]){	unsigned len, files;	unsigned long byte_cnt;	unsigned char *buff, md2out[20], md4out[20], md5out[20];	unsigned int md2len, md4len, md5len;	struct stat statbuf;	R_DIGEST_CTX md2ctxt, md5ctxt, md4ctxt;	FILE *fp;	fprintf(stderr, "MDEMO - MD2/MD4/MD5 Demo Application Using %s.\n", RSAEURO_IDENT);	fprintf(stderr, "MD2/MD4/MD5 RSA Data Security, Inc. Message Digest Algorithms.\n");	/* We expect 1 or more arguments */	if(argc < 2) {		fprintf(stderr, "This program prints the validation information for a file.\n");		fprintf(stderr, "Examples:\n");		fprintf(stderr, "          MDEMO SCAN.EXE\n");		fprintf(stderr, "          MDEMO SCANRES.EXE\n");		exit(1);	}	if((buff = (unsigned char *) calloc(SIZE, 1)) == NULL) {		fprintf(stderr, "Memory Allocation Error.");		exit(1);	}	/* Loop through each filename on the invocation line */	for(files = 1; files < argc; files++) {		printf("\n\tFile Name:  %s\n", argv[files]);		fp = fopen(argv[files],"rb");		if(!fp) {			fprintf(stderr, "\n Sorry, I cannot open the input file.\n");			continue;		}		/* Byte count and hash contexts to initial values */		byte_cnt = 0;		R_DigestInit(&md2ctxt, DA_MD2);		R_DigestInit(&md4ctxt, DA_MD4);		R_DigestInit(&md5ctxt, DA_MD5);		/* Read the file in chunks until done */		while((len = fread(buff, 1, sizeof(buff), fp)) != 0)		{			/* hash next part of file */			R_DigestUpdate(&md2ctxt, buff, len);			R_DigestUpdate(&md4ctxt, buff, len);			R_DigestUpdate(&md5ctxt, buff, len);			/* Byte count of file */			byte_cnt += len;		}		/* finalise hash contexts */		R_DigestFinal(&md2ctxt, md2out, &md2len);		R_DigestFinal(&md4ctxt, md4out, &md4len);		R_DigestFinal(&md5ctxt, md5out, &md5len);		/* Get file info so we can print last modified time for file */		fstat(fileno(fp), &statbuf);		/* Give the user the results */		printf("               Size:  %ld\n", byte_cnt);		printf("               Date:  %s", ctime(&statbuf.st_mtime));		printf("File Authentication:\n");		printf("               MD2 Output - ");		printdigest(md2out, md2len); 		printf("               MD4 Output - ");		printdigest(md4out, md4len); 		printf("               MD5 Output - ");		printdigest(md5out, md5len);		fclose(fp);	}	exit(0);}static void printdigest(unsigned char *out, unsigned int len){	int i;	for(i = 0; i < len; i++)		printf("%02X", *(out+i));	printf("\n");}