SHA-1 is no more secured and path to deprecation

Now its final SHA-1 is no more secured and path to deprecation!!


Look at the google announcement:
https://security.googleblog.com/2017/02/announcing-first-sha1-collision.html

It has been finally proven that the SHA-1 usage in certificates are vulnerable and need to be deprecated.

If you have any certificates you can find what algorithm it uses:
test-vm:~>/usr/bin/openssl x509 -in MyCACert.pem -noout -text | grep "Signature Algorithm"
Signature Algorithm: sha256WithRSAEncryption
Signature Algorithm: sha256WithRSAEncryption

You can also connect to the webserver and see that on the browser security overview.

Just a brief:

What is SHA-2?

SHA-2 (Secure Hash Algorithm 2). The algorithms are collectively known as SHA-2, named after their digest lengths (in bits): SHA-256, SHA-384, and SHA-512

Use Cases?

The SHA-2 hash function is implemented in widely used security applications and protocols, including TLS and SSL, PGP, SSH, S/MIME, and IPsec

Timeline:

SHA-1 should be deprecated by January 2017. (Posting this blog after the period. Idiot ...)

Bash Shell and simple way to pass and parse arguments

I was searching of some simple way to take arguments without using third party parser.
Using third party parser with all permutation and combination makes the shell script bigger.

For eg: ./example -a "arg1" -b "-arg2"

I have seen people writing while with case or using getopt. Examples of such are in abandon (so not giving here).

lets get into the code

#!/bin/bash
function usage()
{
  echo "Usage: $0 -a "arg1" -b "arg2"
  exit 0
}

[ $# -eq 0 ] && usage
#add all your options or flags
for ((i=1;i<=$#;i++));
do
  [ ${!i} = "--help" ] || [ ${!i} = "-h" ] && usage
  [ ${!i} = "-a" ] && ((i++)) && A=${!i} && continue
  [ ${!i} = "-b" ] && ((i++)) && B=${!i} && continue
  echo "Wrong argument ${!i} provided. Run with -h"
  usage && exit 0
done

#======Write your program having all the args =====
echo "You have provided $A and $B"