(Ruby) RSA Encrypt RSA/ECB/OAEPWithSHA1AndMGF1Padding

Demonstrates how to RSA encrypt using RSA/ECB/OAEPWithSHA1AndMGF1Padding. Also demonstrates RSA/ECB/OAEPWithSHA-256AndMGF1Padding. Both of these terms are from Java's JCE. Note: In this context, "ECB" doesn't actually mean anything. It's a symmetric cipher mode that doesn't apply (or make sense) in this context.

Note: This example requires Chilkat v11.0.0 or greater.

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

success = false

# This example assumes the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

rsa = Chilkat::CkRsa.new()

# First load a public key object with a public key.
# In this case, we'll load it from a file.
pubkey = Chilkat::CkPublicKey.new()
success = pubkey.LoadFromFile("qa_data/pem/rsa_public.pem")
if (success == false)
    print pubkey.lastErrorText() + "\n";
    exit
end

# RSA encryption is limited to small amounts of data. The limit
# is typically a few hundred bytes and is based on the key size and
# padding (OAEP vs. PKCS1_5).  RSA encryption is typically used for
# encrypting hashes or symmetric (bulk encryption algorithm) secret keys.
plainText = "Time is an illusion. Lunchtime doubly so."

# Import the public key to be used for encrypting.
success = rsa.UsePublicKey(pubkey)

# To get OAEP padding, set the PkcsPadding property equal to false
rsa.put_PkcsPadding(false)
rsa.put_OaepHash("sha256")

# Indicate we'll want hex output
rsa.put_EncodingMode("hex")

# Encrypt..
usePrivateKey = false
encryptedStr = rsa.encryptStringENC(plainText,usePrivateKey)
print encryptedStr + "\n";

# -------------------------------------------------
# Now decrypt with the matching private key.
rsa2 = Chilkat::CkRsa.new()

privKey = Chilkat::CkPrivateKey.new()
success = privKey.LoadEncryptedPem("qa_data/pem/rsa_passwd.pem","passwd")
if (success == false)
    print privKey.lastErrorText() + "\n";
    exit
end

success = rsa2.UsePrivateKey(privKey)

# Make sure we have the same settings used for encryption.
rsa2.put_PkcsPadding(false)
rsa2.put_EncodingMode("hex")
rsa2.put_OaepHash("sha256")

originalStr = rsa2.decryptStringENC(encryptedStr,true)

print originalStr + "\n";