Lua Requires Chilkat v11.0.0+

RSA Encrypt Hash using SHA256 hash function and SHA1 mask function

See more RSA Examples

How can this Javascript be duplicated using Chilkat?

function a(e, t) {
                var r = s.pki.publicKeyFromPem(e)
                  , n = r.encrypt(t, "RSA-OAEP", {
                    md: s.md.sha256.create(),
                    mgf1: {
                        md: s.md.sha1.create()
                    }
                });
                return s.util.encode64(n)
            }

Note: The OAEP padding uses random bytes in the padding, and therefore each time encryption happens, even using the same data and key, the result will be different -- but still valid. One should not expect to get the same output.

Lua

local chilkat = require("chilkat")

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

local pubkey = chilkat.PublicKey.new()

local sbPem = chilkat.StringBuilder.new()
local bCrlf = true
sbPem:append_line("-----BEGIN PUBLIC KEY-----", bCrlf)
sbPem:append_line("MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA33TqqLR3eeUmDtHS89qF", bCrlf)
sbPem:append_line("3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA", bCrlf)
sbPem:append_line("04DDnEFGAf+kDQiNSe2ZtqC7bnIc8+KSG/qOGQIVaay4Ucr6ovDkykO5Hxn7OU7s", bCrlf)
sbPem:append_line("Jp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwF", bCrlf)
sbPem:append_line("wnxCsU5+UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUE", bCrlf)
sbPem:append_line("f0YN3/Q0auBkdbDR/ES2PbgKTJdkjc/rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1W", bCrlf)
sbPem:append_line("SwIDAQAB", bCrlf)
sbPem:append_line("-----END PUBLIC KEY-----", bCrlf)

-- Load the public key object from the PEM.
local success = pubkey:load_from_string(sbPem:get_as_string())
if not success then
    print(pubkey.last_error_text)
    return
end

local originalData = "This is the original data to be SHA-256 hashed and RSA encrypted."

-- First we SHA-256 hash the original data to get the hash in base64 format:
local crypt = chilkat.Crypt2.new()
crypt.hash_algorithm = "SHA-256"
crypt.encoding_mode = "base64"
local hashBase64 = crypt:hash_string_enc(originalData)

-- Setup RSA to use OAEP padding with SHA-1 for the mask function.
local rsa = chilkat.Rsa.new()
rsa.pkcs_padding = false
rsa.oaep_hash = "SHA256"
rsa:use_public_key(pubkey)
rsa.encoding_mode = "base64"

-- We can provide a binary encoding mode, such as "base64", "hex", "base64url", etc.
-- for the Charset property.   The Charset property was previously limited to character encodings, such as
-- "utf-8", "iso-8859-1", etc.  If a binary encoding is used, then the string passed in is decoded to the binary
-- bytes as indicated.  (If an actual charset, such as "utf-8" is used, then the input string is converted to the
-- byte representation of the charset, and then encrypted.)

-- Given that a hash is composed of non-text binary bytes, we'll set the Charset property equal to "base64"
-- (because we have the base64 hash from above).
rsa.charset = "base64"

-- Note: The OAEP padding uses random bytes in the padding, and therefore each time encryption happens,
-- even using the same data and key, the result will be different --  but still valid.  One should not expect
-- to get the same output.
local bUsePrivateKey = false
local encryptedStr = rsa:encrypt_string_enc(hashBase64, bUsePrivateKey)
if not rsa.last_method_success then
    print(rsa.last_error_text)
    return
end

print("Base64 RSA encrypted output: " .. encryptedStr)