decode_sniffer.c

一个网络工具包,可以嗅探email和http等数据包中的密码等信息.注意要先把libnet-1.0.2a.tar.gz和 libnids-1.16.tar.gz装上,不然会因为缺少库函数而无法编译和安

/*
  decode_sniffer.c

  Network Associates Sniffer.
  
  Copyright (c) 2000 Anonymous <nobody@localhost>
  Copyright (c) 2000 Dug Song <[e-mail]>
 
  $Id: decode_sniffer.c,v 1.3 2000/11/06 14:08:43 dugsong Exp $
*/

#include "config.h"

#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include "base64.h"
#include "decode.h"

int 
decode_sniffer(u_char *buf, int len, u_char *obuf, int olen)
{
	u_int i, opcode;
	
	if (len < 36 || buf[0] != 5)
		return (0);
	
	opcode = pletohs(&buf[6]);
	
	if (opcode == 260) {
		if (buf[32] == 0)
			return (strlcpy(obuf, "[]\n", olen));
	}
	else if (opcode == 261) {
		if (pletohl(&buf[32]) == -1)
			return (strlcpy(obuf, "[]\n", olen));
	}
	else return (0);
	
	buf[len - 3]= '\0'; strtok(&buf[32], "\r\n");
	snprintf(obuf, olen, "%s [", &buf[32]);
	len = strlen(obuf);
	i = base64_pton(&buf[32], &obuf[len], olen - len - 3);
	obuf[len + i] = '\0';
	strlcat(obuf, "]\n", olen);
	
	return (strlen(obuf));
}