Ruby Requires Chilkat v11.0.0+

RSA Encrypt String to Encoded Result and Reverse

See more RSA Examples

Demonstrates how to RSA encrypt a string to a base64 encoded result, and the reverse. Ruby

require 'chilkat'

success = false

#  The RSA public key is used for encryption, and the private key for decryption.

#  The public key's role is to make encryption accessible to anyone while ensuring that
#  only the private key holder can decrypt the messages.
#  The public key is designed to be widely distributed so anyone can use it to encrypt messages
#  intended for the owner of the private key.

glob = Chilkat::CkGlobal.new()
glob.put_DefaultUtf8(true)

#  Load our 2048-bit RSA public key.
pubKey = Chilkat::CkPublicKey.new()
#  In all Chilkat methods expecting a path, you pass either absolute or relative paths.
success = pubKey.LoadFromFile("rsaKeys/myTestRsaPublic.pem")
if (success == false)
    print pubKey.lastErrorText() + "\n";
    exit
end

rsa = Chilkat::CkRsa.new()

#  Tell RSA to use the public key.
rsa.UsePublicKey(pubKey)

#  RSA encryption is for small amounts of data, on the order of 200 bytes or less.
#  The maximum number of bytes that can be RSA encrypted depends
#  on the RSA key size and padding scheme (OAEP padding vs PKCS#1 v1.5 padding).
#  For specific limits, see: RSA Encryption Maximum Number of Bytes

#  Encrypt the utf-8 byte representation of the string.
rsa.put_Charset("utf-8")
rsa.put_EncodingMode("base64")

#  Be Careful when Using non-us-ascii String Literals in Source Code
encryptedB64 = rsa.encryptStringENC("Élève français dîne à côté d’un café où l’on sert déjà du gâteau au chocolat et des éclairs délicieux",false)

#  ------------------------------------------------------------------------------------------------------------------------
#  Let's decrypt, which requires the matching private key...

#  Load the matching 2048-bit RSA private key.
privKey = Chilkat::CkPrivateKey.new()
password = "secret"
success = privKey.LoadAnyFormatFile("rsaKeys/myTestRsaPrivate.pem",password)
if (success == false)
    print privKey.lastErrorText() + "\n";
    exit
end

#  Tell the RSA object to use the private key.
rsa.UsePrivateKey(privKey)

#  Indicate that after decrypting the resultant decrypted bytes contains the utf-8 byte representation of the text.
rsa.put_Charset("utf-8")
rsa.put_EncodingMode("base64")
originalText = rsa.decryptStringENC(encryptedB64,true)
if (success == false)
    print rsa.lastErrorText() + "\n";
    exit
end

print "Original text = " + originalText + "\n";
print "Success." + "\n";