Lua Requires Chilkat v11.0.0+

Create a Hash Signature for Value Added Tax Audit SOAP Message for Angola

See more OpenSSL Examples

Demonstrates how to create a hash signature that is required in Value Added Tax Audit Files in Angola, Africa.

It is the following two instructions that should be used to create a hash value to be put into a <hash></hash> field in SOAP XML file containing the tax data for the VAT authorities:

openssl dgst -shal -sign private.pem -outRegisto1.shal Registo1.txt

then

openssl enc -base64 - in Registo1.shal -out Registo1.b64 -A

Lua

local chilkat = require("chilkat")

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

local pkey = chilkat.PrivateKey.new()

-- Load the private key from an PEM file.
-- Provide the password in the 2nd argument.
-- If no password is needed, just pass an empty string.
local success = pkey:load_any_format_file("qa_data/rsa/rsaPrivKey_secret.pem", "secret")
if not success then
    print(pkey.last_error_text)
    return
end

-- Assuming this is an RSA private key..
local rsa = chilkat.Rsa.new()

-- Import the private key into the RSA object:
success = rsa:use_private_key(pkey)
if not success then
    print(rsa.last_error_text)
    return
end

-- OpenSSL uses big-endian.
rsa.little_endian = false

-- SHA1 hash and sign, and return base64.
rsa.encoding_mode = "base64"
local b64sig = rsa:sign_string_enc("2018-05-18,2018-05-18T11:22:19;FAC 001/18;53.00;", "sha1")
print(b64sig)

-- The signature is equal in size to your private key.  For example, if you have a 1024-bit RSA key,
-- then 1024 bits = 128 bytes.   When 128 bytes is base64 encoded, the result is a string approximately
-- 4/3rds the size of the original.  128 * 4 / 3 = (approximately) 172 bytes.

-- If your RSA key is 2048-bits, then your signature will be twice as long.