/*
 * md5cmd.c
 *
 * Copyright (c) 2002 - 2003 Apple Computer, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of Apple Computer, Inc. nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#if HAVE_CONFIG_H
#include <config.h>
#endif

#include <tcl.h>

#if HAVE_STRING_H
#include <string.h>
#endif

#if defined(HAVE_LIBCRYPTO) && !defined(HAVE_LIBMD)

/* Minimal wrapper around OpenSSL's libcrypto, as a compatibility
 * layer for FreeBSD's libmd library.
 * Originally written by: Rob Braun (bbraun) 1/18/2002
 */

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

#include <openssl/md5.h>

/* This is a magic number taken from the FreeBSD libmd Makefile */
#define LENGTH 16

#define MD5Init(x) MD5_Init(x)
#define MD5Update(x,y,z) MD5_Update(x,y,z)
#define MD5Final(x,y) MD5_Final(x,y)

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

    if (!buf)
        buf = malloc(2*LENGTH + 1);
    if (!buf)
        return 0;
    MD5Final(digest, ctx);
    for (i = 0; i < 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)
{
    unsigned char buffer[BUFSIZ];
    MD5_CTX ctx;
    int f,i,j;

    MD5Init(&ctx);
    f = open(filename,O_RDONLY);
    if (f < 0) return 0;
    while ((i = read(f,buffer,sizeof buffer)) > 0) {
        MD5Update(&ctx,buffer,i);
    }
    j = errno;
    close(f);
    errno = j;
    if (i < 0) return 0;
    return MD5End(&ctx, buf);
}

char *MD5Data(const unsigned char *data, unsigned int len, char *buf)
{
	MD5_CTX ctx;
	MD5Init(&ctx);
	MD5Update(&ctx, data, len);
	return MD5End(&ctx, buf);
}
#elif defined(HAVE_LIBMD)
#include <sys/types.h>
#include <md5.h>
#else
#error libcrypto or libmd are required
#endif

int MD5Cmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[])
{
#pragma unused (clientData)
	char *file, *action;
	char buf[33];
	const char usage_message[] = "Usage: md5 file ?file?";
	const char error_message[] = "Could not open file: ";
	Tcl_Obj *tcl_result;

	if (objc != 3) {
		Tcl_WrongNumArgs(interp, 1, objv, "action ?file?");
		return TCL_ERROR;
	}

	/*
	 * Only the 'file' action is currently supported
	 */
	action = Tcl_GetString(objv[1]);
	if (strcmp(action, "file") != 0) {
		tcl_result = Tcl_NewStringObj(usage_message, sizeof(usage_message) - 1);
		Tcl_SetObjResult(interp, tcl_result);
		return TCL_ERROR;
	}
	file = Tcl_GetString(objv[2]);

	if (!MD5File(file, buf)) {
		tcl_result = Tcl_NewStringObj(error_message, sizeof(error_message) - 1);
		Tcl_AppendObjToObj(tcl_result, Tcl_NewStringObj(file, -1));
		Tcl_SetObjResult(interp, tcl_result);
		return TCL_ERROR;
	}
	tcl_result = Tcl_NewStringObj(buf, sizeof(buf) - 1);
	Tcl_SetObjResult(interp, tcl_result);
	return TCL_OK;
}