Lua Requires Chilkat v11.0.0+

RSA Encrypt RSA/ECB/OAEPWithSHA1AndMGF1Padding

See more RSA Examples

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. Lua

local chilkat = require("chilkat")

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

local rsa = chilkat.Rsa.new()

-- First load a public key object with a public key.
-- In this case, we'll load it from a file.
local pubkey = chilkat.PublicKey.new()
local success = pubkey:load_from_file("qa_data/pem/rsa_public.pem")
if not success then
    print(pubkey.last_error_text)
    return
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.
local plainText = "Time is an illusion. Lunchtime doubly so."

-- Import the public key to be used for encrypting.
success = rsa:use_public_key(pubkey)

-- To get OAEP padding, set the PkcsPadding property equal to false
rsa.pkcs_padding = false
rsa.oaep_hash = "sha256"

-- Indicate we'll want hex output
rsa.encoding_mode = "hex"

-- Encrypt..
local usePrivateKey = false
local encryptedStr = rsa:encrypt_string_enc(plainText, usePrivateKey)
print(encryptedStr)

-- -------------------------------------------------
-- Now decrypt with the matching private key.
local rsa2 = chilkat.Rsa.new()

local privKey = chilkat.PrivateKey.new()
success = privKey:load_encrypted_pem("qa_data/pem/rsa_passwd.pem", "passwd")
if not success then
    print(privKey.last_error_text)
    return
end

success = rsa2:use_private_key(privKey)

-- Make sure we have the same settings used for encryption.
rsa2.pkcs_padding = false
rsa2.encoding_mode = "hex"
rsa2.oaep_hash = "sha256"

local originalStr = rsa2:decrypt_string_enc(encryptedStr, true)

print(originalStr)