Lua Requires Chilkat v11.0.0+

Encrypt with Chilkat, Decrypt with OpenSSL

See more OpenSSL Examples

Demonstrates how to RSA encrypt a string using Chilkat, and then shows the corresponding OpenSSL command to RSA decrypt. The OpenSSL command to decrypt is as follows:

openssl rsautl -decrypt -inkey VP_Private.pem -in rsa_encrypted.bin -out original.txt

Lua

local chilkat = require("chilkat")

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

local rsa = chilkat.Rsa.new()

-- Note: RSA encryption uses the public key.
-- RSA decryption uses the private key.
-- The reason is that the public key can be freely provided to anybody.  This allows anybody
-- to send an encrypted message to the private key owner, and only the private key owner
-- can decrypt.
local key = chilkat.PublicKey.new()

-- Load an RSA public key from a PEM file:
local success = key:load_from_file("qa_data/pem/VP_Public.pem")
if not success then
    print(key.last_error_text)
    return
end

-- Load the public key into the RSA object.
success = rsa:use_public_key(key)
if not success then
    print(rsa.last_error_text)
    return
end

local strToEncrypt = "00000000;XYZ2-3BHQ-ABCD-MMVV;6MY1-GHJK-9LRR;0"

-- The LittleEndian property is false by default, but it is set here
-- anyway to show that LittleEndian byte ordering is required for OpenSSL compatibility.
rsa.little_endian = false

local usePrivateKey = false

encryptedBytes = ERROR: Method not in Chilkat for Lua: Rsa.EncryptString
rsa:ERROR()
if not rsa.last_method_success then
    print(rsa.last_error_text)
    return
end

-- The OpenSSL command to decrypt would be this:
-- openssl rsautl -decrypt -inkey VP_Private.pem -in rsa_encrypted.bin -out original.txt

local fac = chilkat.FileAccess.new()
success = ERROR: Method not in Chilkat for Lua: FileAccess.WriteEntireFile
fac:ERROR()
if not success then
    print(fac.last_error_text)
    return
end

print("RSA Encryption Succeeded.")