/* mdXhl.c * ----------------------------------------------------------------------------
 * "THE BEER-WARE LICENSE" (Revision 42):
 * <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
 * can do whatever you want with this stuff. If we meet some day, and you think
 * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
 * ----------------------------------------------------------------------------
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libmd/mdXhl.c,v 1.19 2006/01/17 15:35:56 phk Exp $");

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>

#include "md5.h"

char *
MD5End(MD5_CTX *ctx, char *buf)
{
        int i;
        unsigned char digest[MD5_DIGEST_LENGTH];
        static const char hex[]="0123456789abcdef";

        if (!buf)
                buf = malloc(2*MD5_DIGEST_LENGTH + 1);
        if (!buf)
                return 0;
        MD5Final(digest, ctx);
        for (i = 0; i < MD5_DIGEST_LENGTH; i++) {
                buf[i+i] = hex[digest[i] >> 4];
                buf[i+i+1] = hex[digest[i] & 0x0f];
        }
        buf[i+i] = '\0';
        return buf;
}

char *
MD5File(const char *filename, char *buf)
{
        return (MD5FileChunk(filename, buf, 0, 0));
}

char *
MD5FileChunk(const char *filename, char *buf, off_t ofs, off_t len)
{
        unsigned char buffer[BUFSIZ];
        MD5_CTX ctx;
        struct stat stbuf;
        int f, i, e;
        off_t n;

        MD5Init(&ctx);
        f = open(filename, O_RDONLY);
        if (f < 0)
                return 0;
        if (fstat(f, &stbuf) < 0)
                return 0;
        if (ofs > stbuf.st_size)
                ofs = stbuf.st_size;
        if ((len == 0) || (len > stbuf.st_size - ofs))
                len = stbuf.st_size - ofs;
        if (lseek(f, ofs, SEEK_SET) < 0)
                return 0;
        n = len;
        i = 0;
        while (n > 0) {
                if (n > sizeof(buffer))
                        i = read(f, buffer, sizeof(buffer));
                else
                        i = read(f, buffer, n);
                if (i < 0) 
                        break;
                MD5Update(&ctx, buffer, i);
                n -= i;
        } 
        e = errno;
        close(f);
        errno = e;
        if (i < 0)
                return 0;
        return (MD5End(&ctx, buf));
}

char *
MD5Data (const void *data, unsigned int len, char *buf)
{
        MD5_CTX ctx;

        MD5Init(&ctx);
        MD5Update(&ctx,data,len);
        return (MD5End(&ctx, buf));
}