Zig 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

Zig

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

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

    const pkey = try chilkat.PrivateKey.init();
    defer pkey.deinit();

    // 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.
    pkey.loadAnyFormatFile("qa_data/rsa/rsaPrivKey_secret.pem", "secret") catch {
        std.debug.print("{s}\n", .{try pkey.getLastErrorText(alloc)});
        return;
    };

    // Assuming this is an RSA private key..
    const rsa = try chilkat.Rsa.init();
    defer rsa.deinit();

    // Import the private key into the RSA object:
    rsa.usePrivateKey(pkey) catch {
        std.debug.print("{s}\n", .{try rsa.getLastErrorText(alloc)});
        return;
    };

    // OpenSSL uses big-endian.
    rsa.setLittleEndian(false);

    // SHA1 hash and sign, and return base64.
    rsa.setEncodingMode("base64");
    const b64sig = try rsa.signStringENC(alloc, "2018-05-18,2018-05-18T11:22:19;FAC 001/18;53.00;", "sha1");
    std.debug.print("{s}\n", .{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.
}