require 'openssl' #Import your private/public keypair into separate objects to play with priv = OpenSSL::PKey::RSA.new(File.read('test1.priv')) pub = OpenSSL::PKey::RSA.new(File.read('test1.pub')) #Use your public key to encrypt some data #Here, 3 means use no padding (I needed it for some testing) #Here I used 56bit keys and no padding which is why my input plaintext must be 56bits (7 characters) #If you want the default of PKCS#1 padding, just remove the '3' argument crypted = pub.public_encrypt("123456\n", 3) #Now decrypt using your private key object (must supply same padding as before, or leave off for default) decrypted = priv.private_decrypt(crypted,3)
Above I created the .priv and .pub using the following openssl commands:
#I chose 56 bits for testing, if used in reality it should be much higher like 2048 openssl genrsa -out test1.priv 56 #Using your private key, create a public key openssl rsa -in test1.priv -out test1.pub -outform PEM -pubout
