README.md

RSA with openssl

This :pk_rsa package uses system command openssl to generate key pairs. Your system must have openssl installed and included in the PATH. If you don't need to create key pairs with this package you don't need it to encrypt and decrypt. The "pk" in the package name refers to :public_key of erlang which we use.

There are other RSA packages but I wanted to embed base64 option.Make the package simpler and more readable.

Usage

To generate key pair with openssl we use RSA.generate_pair it will return a tupple containing keys. Keys are formatted as pem file strings.

iex(1)> {private_key, public_key} = RSA.generate_pair()
iex(2)> private_key
"-----BEGIN RSA PRIVATE KEY-----\nMIIEpAIBAAKCAQEA6mz...
iex(3)> public_key
"-----BEGIN PUBLIC KEY-----\nMIIBIjANBgk

To encrypt messages we have two functions RSA.encrypt_priv/3 for encrypting with private key and RSA.encrypt_pub/3 for encrypting with public key. Third parameter is optional boolean to tell the function we want to use base64 format.

iex(4)> RSA.encrypt_priv("hello", private_key)
<<38, 219, 161, 223, 29, 149, 176, 251, 218, 69, 161, 3, 39, 73, 2, 153, 40, ...>>
iex(5)> RSA.encrypt_priv("hello", private_key, true)
'Jtuh3x2VsPvaRaEDJ0kCmSjPtpZ0jm/KNVr2NM...

When you encrypt with private_key you need to use public_key to decrypt. Same way you can encrypt with public_key and decrypt with private_key

You can also sign and verify messages with RSA.sign/3 and RSA.verify/4 functions. Last arguement is oprional if true base64 will be used.

iex(6)> signature = RSA.sign("hello", private_key, true)
'HbNqLYt5MxDayLBnv81RKBvqN...
iex(7)> RSA.verify("hello",signature, public_key, true)
true

Installation

The package can be installed by adding pk_rsa to your list of dependencies in mix.exs:

def deps do
  [
    {:pk_rsa, "~> 0.1.0"}
  ]
end

Documentation can be generated with ExDoc and can be found at https://hexdocs.pm/pk_rsa.

Thanks

Generate pair function is taken from elefthei/krypto