AES128 / AES256 CBC with PKCS7Padding in Ruby

gistfile1.rb

require "openssl"
require "digest"

def aes128_cbc_encrypt(key, data, iv)
  key = Digest::MD5.digest(key) if(key.kind_of?(String) && 16 != key.bytesize)
  iv = Digest::MD5.digest(iv) if(iv.kind_of?(String) && 16 != iv.bytesize)
  aes = OpenSSL::Cipher.new('AES-128-CBC')
  aes.encrypt
  aes.key = key
  aes.iv = iv
  aes.update(data) + aes.final
end

def aes256_cbc_encrypt(key, data, iv)
  key = Digest::SHA256.digest(key) if(key.kind_of?(String) && 32 != key.bytesize)
  iv = Digest::MD5.digest(iv) if(iv.kind_of?(String) && 16 != iv.bytesize)
  aes = OpenSSL::Cipher.new('AES-256-CBC')
  aes.encrypt
  aes.key = key
  aes.iv = iv
  aes.update(data) + aes.final
end

def aes128_cbc_decrypt(key, data, iv)
  key = Digest::MD5.digest(key) if(key.kind_of?(String) && 16 != key.bytesize)
  iv = Digest::MD5.digest(iv) if(iv.kind_of?(String) && 16 != iv.bytesize)
  aes = OpenSSL::Cipher.new('AES-128-CBC')
  aes.decrypt
  aes.key = key
  aes.iv = iv
  aes.update(data) + aes.final
end

def aes256_cbc_decrypt(key, data, iv)
  key = Digest::SHA256.digest(key) if(key.kind_of?(String) && 32 != key.bytesize)
  iv = Digest::MD5.digest(iv) if(iv.kind_of?(String) && 16 != iv.bytesize)
  aes = OpenSSL::Cipher.new('AES-256-CBC')
  aes.decrypt
  aes.key = key
  aes.iv = iv
  aes.update(data) + aes.final
end

Hey in line 24 and 32 you are doing the digest again.

And thank you for the code ;)

@efreesen is right. there is problem on line 24 and 32.

it should be
aes.key = key

Nice. If I want to encrypt using openssl command line and then decrypt in Ruby then I always get things messed up in the Ruby decypt code. I think it would be helpful to have the command line analogs for comparison for newbies.

Thank you, this is helpful

Thanks, fixed

awesome!

How do you decrypt these in java?

thanks, it works in ruby ​​2.4 on windows 10!

How to go for PKCS5 encrypting in Ruby? I can't find any information on this.