(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.

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

require 'chilkat'

# 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 != true)
    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.ImportPublicKeyObj(pubkey)

# To get OAEP padding, set the OaepPadding property:
rsa.put_OaepPadding(true)

# To use SHA1 or SHA-256, set the OaepHash property
rsa.put_OaepHash("sha256")
# for SHA1 --
rsa.put_OaepHash("sha1")

# 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 != true)
    print privKey.lastErrorText() + "\n";
    exit
end

success = rsa2.ImportPrivateKeyObj(privKey)

# Make sure we have the same settings used for encryption.
rsa2.put_OaepPadding(true)
rsa2.put_EncodingMode("hex")
rsa2.put_OaepHash("sha1")

originalStr = rsa2.decryptStringENC(encryptedStr,true)

print originalStr + "\n";