Simple Golang port scanner

Simple and powerful golang port scanner

https://github.com/Sinute/golang-portScan

Who needs any other port scanner when you can take this one file and compile it to run on both Linux and Windows? And better yet, change the number to workers from 5 to 300 now you can scan an entire /24 network in 3 seconds.

Note that the program seem to have an issue with "\r" and "\n", which suggests that the program may have been developed on a Mac. No problem, simply replace swap "\r" and "\n" in the source  and you are ready to go.

How to extract file from RPM packages without installing it

rpm2cpio myrpmfile.rpm | cpio -idmv

Download Java JRE JDK using wget script

wget --no-cookies --no-check-certificate --header "Cookie: gpw_e24=http%3A%2F%2Fwww.oracle.com%2F" "http://download.oracle.com/otn-pub/java/jdk/7u4-b20/jdk-7u4-linux-x64.tar.gz"

More Info get http://ivan-site.com/2012/05/download-oracle-java-jre-jdk-using-a-script/

Virtualbox high network latency with multiple CPU Cores

On Virtualbox 4.2, if you assign multiple cores to your VM, and you are running Linux Guest, you may experience high network latency (ssh typing is sporadic even on local GigE network).

This is a bug with Virtualbox.

The solution: Change your VM Ethernet type to PCnet. Then it works!

Here is the link to the bug report: https://www.virtualbox.org/ticket/10157

A good Windows SSH/Telnet Server

http://www.kpym.com/

• Free, Open source, 
• works with putty in full color, and full window size
• and command auto complete works well
• what else could I ask for?

linux dummy interface and renaming

In linux, there is a kernel module called "dummy", which allows you to generate dummy network interfaces such as "dummy0", "dummy1", etc.

1. sudo modprobe dummy numdummies=2
2. now you can do "ifconfig dummy0 192.168.1.124" to give it an IP address.
3. you can also rename the dummy interface with the following command:
        ip link set dummy0 name eth3
you need to "down" the interface before running the command above.

With the combination of dummy interfaces and ability to rename dummy interfaces, you can do a lot of fun things with them.

initramfs with boot argument init=/bin/sh

If you use a Linux kernel with initramfs, the boot argument "init=/bin/sh" would not work. The correct one is "rdinit=/bin/sh". Aha. Gotcha.

U-boot environment variables

Just a pointer link:
http://www.denx.de/wiki/DULG/UBootEnvVariables

Add new file type to ack-grep

If you use ack as your grep replacement, and would like to add a new file type, do this:

Create a file at ~/.ackrc with the following line (change Ruby to your file type, and .haml,etc to your actual file extension):

--type-add=ruby=.haml,.rake,.rsel

How to hide/remove OS field in Bugzilla

This method uses javascript to hide the unwanted fields

1. edit template/en/default/global/header.html.tmpl. Search for "global.js". After the line "[% END %]" add the following lines:

    [% starting_js_urls.push('//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js') %]

    [% FOREACH javascript_url = starting_js_urls %]
      [% PROCESS format_js_link %]
    [% END %]
    [% starting_js_urls.push('js/my.js') %]

    [% FOREACH javascript_url = starting_js_urls %]
      [% PROCESS format_js_link %]
    [% END %]

2. create the file js/my.js with the following contents:

$(document).ready(function(){

        $("#os_guess_note").parent().hide();

        $("#field_container_op_sys").parent().hide();

        $("#field_container_rep_platform").parent().hide();

});

This hides three fields: OS, OS comment, and Hardware.

To remove more clutters, use the following js:

$(document).ready(function(){
        $("#os_guess_note").parent().hide();
        $("#field_container_op_sys").parent().hide();
        $("#field_container_rep_platform").parent().hide();
        $("#op_sys").closest("tr").hide();
        $("#bz_url_input_area").closest("tr").hide();
        $("#tag_container").closest("tr").hide();
        $("#dependson").closest("tr").hide();
        $("#blocked_input_area").closest("tr").hide();
        $("#show_dependency_tree_or_graph").closest("tr").hide();
        $("td.bz_section_spacer").closest("tr").hide();
        $(".bz_collapse_expand_comments").closest("td").hide();
        $("div.bz_add_comment").hide();
        $("#xml").hide();

        $("#comment").attr("rows","2");
        $("#attachment_table").hide().before("<button id='tz_bug_edit' style='width:50px'> <b>Edit</b> </button>");
        $("#add_comment").hide();
        $("#tz_bug_edit").prevAll("br").remove();
        $("#tz_bug_edit").click(function(){
                if ($("#attachment_table").is(":visible")){
                        $("#attachment_table").hide();
                        $("#add_comment").hide();
                }else{
                        $("#attachment_table").show();
                        $("#add_comment").show();
                }
                return false;
        });
});
        $("#bz_show_bug_column_1").append($("#bz_show_bug_column_2").html());
        $("#bz_show_bug_column_2").remove();
        $("table.edit_form").css("width","auto").css("float","right").find("th").css("text-align","left");

        $("#changeform").css("min-height","400px");

You can also change skins/standard/global.css to remove hyperlink underline, and change default font:

a {

        text-decoration: none;

}

/* this already exists, just edit it */

body, td, th, input {

    font-family: Verdana, sans-serif;

    font-size: 11pt;

}

GOLANG SSL Server and Client example

https://gist.github.com/spikebike/2232102

Below is my simple static "SSL Proxy" that listens on port 8000, and connects to another machine 10.3.0.124:443, and the proxy logs traffic both ways on screen.

To generate key.pem and cert.pem, you can use openssl, or use go team's simple program included in go package: http://golang.org/src/pkg/crypto/tls/generate_cert.go

package main
import (
        "io"
        "log"
        "net"
        "fmt"
        "os"
        "crypto/tls"
        "crypto/rand"
)

func checkError(err error) {
        if err != nil {
                fmt.Fprintf(os.Stderr, "Fatal error: %s", err.Error())
                os.Exit(1)
        }
}

/* slower, by we can print/log everything */
func myrawcopy(dst,src net.Conn) (written int64, err error) {
    buf := make([]byte, 32*1024)
    for {
        nr, er := src.Read(buf)
        if nr > 0 {
                        fmt.Printf("%s",string(buf[0:nr]));
            nw, ew := dst.Write(buf[0:nr])
            if nw > 0 {
                written += int64(nw)
            }
            if ew != nil {
                err = ew
                break
            }
            if nr != nw {
                err = io.ErrShortWrite
                break
            }
        }
        if er == io.EOF {
            break
        }
        if er != nil {
            err = er
            break
        }
    }
    return written, err
}

func myiocopy(dst net.Conn, src net.Conn){
        myrawcopy(dst, src)
        //io.Copy(dst,src);
        dst.Close();
        src.Close();
}

func handleclient(c net.Conn){
        config := tls.Config{InsecureSkipVerify: true}
        conn, err := tls.Dial("tcp", "10.3.0.124:443", &config)
        checkError(err)

        go myiocopy(conn,c)

        //io.Copy(c, conn)
        myrawcopy(c, conn)
        c.Close()
        conn.Close();
}

func main() {
        cert, err := tls.LoadX509KeyPair("cert.pem", "key.pem")
        if err != nil {
                log.Fatalf("server: loadkeys: %s", err)
        }
        config := tls.Config{Certificates: []tls.Certificate{cert}}
        config.Rand = rand.Reader
        service := "0.0.0.0:8000"
        listener, err := tls.Listen("tcp", service, &config)
        if err != nil {
                log.Fatalf("server: listen: %s", err)
        }
        log.Printf("server: listening on %s for https, connects to https://10.3.0.124:443",service)
        for {
                conn, err := listener.Accept()
                if err != nil {
                        log.Printf("server: accept: %s", err)
                        break
                }
                defer conn.Close()
                log.Printf("server: accepted from %s", conn.RemoteAddr())
                go handleclient(conn)
        }
}

Free - Remote Desktop Control Software

To sum it up: 

For business, Use LogMeIn for unattended, Join.me for attended.

For personal: Use TeamViewer.

The first and highest rated product in the unattended category is LogMeIn. This is a web-based service that's extremely easy to set up and use and can be accessed from any PC with a browser. The free version won't allow file transfer or remote printing but is a great solution for accessing your remote data as well as file sharing. Registration is required before using the product. It is really meant to be an 'install and leave it' kind of tool and not for the 'quick connect to help a friend' scenario. I still very much believe that the features and speed of LogMeIn are unmet by any other product and worth the extra hassle if you have access to the other machine(s) or means to connect remotely and install it. It is free for personal and commercial use.

Next is TeamViewer. It is very reliable, allows both attended and unattended control and has great features. There is a portable version of the viewer if you want to use an application or they also have a web-based control site that requires no installation to remotely control computers. The web-based version uses HTML and Flash, so it is usable even if the browser or firewall doesn't allow Java or ActiveX. TeamViewer is a commercial product and is only free  for personal use. Any commercial use is prohibited by the TeamViewer use policy.

The fastest solution in the attended category is Join.me. Its small 1 MB download and simple security code make it very quick to establish a remote session.

The last solution in this category is Mikogo. Mikogo is not the fastest nor is it the most reliable, but it offers the most features of any of the solutions in this article. It is a full-featured solution comparable to the commercial Citrix GotoMeeting product with features such as presenter switching, remote control, white board sharing, file sharing and session recording.

Source: http://www.techsupportalert.com/best-free-remote-access-software.htm

To open a page in a frame using javascript

"javascript:top.frames['framename'].location = 'filename.html';return true;"

A list of SSL/HTTPS sniffer/proxy/dump

1. mitmproxy, written in Python, includes a ncurse-based UI, or the console-based mitmdump. Able to generate SSL certs on the fly. http://mitmproxy.org/
2. TCPCather: http://www.tcpcatcher.org/. Looks really good.
3. sslsniff: by the famous hacker moxie0: https://github.com/moxie0/sslsniff
4. burp (the free version): http://www.portswigger.net/burp/proxy.html

I personally used mitmproxy to my satisfaction. 

vim regex search tips

1. $ < > does not need to be escaped.
2. [ ] & needs to be escaped
3. [a-zA-Z] sometimes can be better accepted than \a (for alphabet)
4. For replacement, & means the matched term

hg serve multiple projects

To use "hg serve" to serve multiple project internally (with your LAN). Create a file named webconf (it can be any name) with the following content:



[collections]
repos/ = .

[extensions]
hgext.highlight=

[web]
allow_push = *
push_ssl = false
pygments_style = vs
style = gitweb

Then in system start up run this:

cd your_hg_directory && sudo -u your-name hg serve --web-conf ./webconf

I like the "gitweb" style because it gives you date on files. The default style is "paper". Other styles can be:

atom
coal
gitweb
monoblue
paper
raw
rss
spartan

shrew vpn masquerade on Linux

Once your have your VPN client running on a Linux box, sometimes you would like to share that link with that machines on your LAN (either physical LAN or virtual LAN such as Virtual Machines).

Because shrew uses the kernel IPsec VPN, the iptables masquerade rule does not work on the virtual tap0 interface. There does not seem to exist an easy fix.

The work around I have is to install a linux virtual machine (virtualbox) on the host, which has two NICs, one is NAT, the other one is bridging. Then run iptables masquerade on the virtual Linux, taking traffic from the bridged NIC, and send it out to the NATed NIC. On the host, since virtualbox behaves just like any other application, it is able to access all the VPNed network resources. Bingo!

It works well here. Let me know your thoughts.

shrew vpn client on Linux for Cisco Concentrator

To talk to a Cisco VPN Concentrator, one can use "vpnc" or "shrew vpn client".

My vpnc only stays up for a few hours, while on Windows the Cisco VPN client can stay up for days. So I wanted to give shrew a try.

Shrew can import Cisco .pcf configuration file. After that, a connection entry is created. However, you probably will need to modify the profile for it to work. On the "qikea" window, right click on the profile, then "Modify", go to tab "Phase 2" and make your choices instead of auto. For example, try change PFS Group to "2". This worked for many people.

If you are interested, you can try to use the tool "ike-scan" to probe your vpn server and find out exactly the parameters for this tab.

That solved my problem.

The following screenshot is a Windows screenshot, but the Linux one is very similar.



I got the this tip from the following post:
http://www.rhyous.com/2009/10/29/windows-7-64-bit-vpn-client-shrewsoft/

Text to ASCII Art

Under Linux, use the program "figlet" to turn regular text info a ASCII art text.

Example:


 figlet hello
 _          _ _
| |__   ___| | | ___
| '_ \ / _ \ | |/ _ \
| | | |  __/ | | (_) |
|_| |_|\___|_|_|\___/


figlet -W hello (wide version)
  _              _   _
 | |__     ___  | | | |   ___
 | '_ \   / _ \ | | | |  / _ \
 | | | | |  __/ | | | | | (_) |
 |_| |_|  \___| |_| |_|  \___/


You can choose different style too:


figlet -f banner -W hello

 #    #  ######  #       #        ####
 #    #  #       #       #       #    #
 ######  #####   #       #       #    #
 #    #  #       #       #       #    #
 #    #  #       #       #       #    #
 #    #  ######  ######  ######   ####

figlet -f bubble -W hello
   _     _     _     _     _
  / \   / \   / \   / \   / \
 ( h ) ( e ) ( l ) ( l ) ( o )
  \_/   \_/   \_/   \_/   \_/

Use "figlist" to list all the styles.

Fix: vim indent not working

If you loaded a new indent file or syntax file under ~/.vim/ and it is not taking effect, make sure you have the following line in your ~/.vimrc file:


filetype plugin indent on

This turns on filetype detection, filetype plugin, and filetype-indent. 

More at http://vimdoc.sourceforge.net/htmldoc/filetype.html