Lua

Combine Timestamp Reply and Content File into a TimeStampData

See more ASN.1 Examples

Demonstrates how to combine a timestamp reply (RFC 3161) with a data file (any type of file) to create a TimeStampData structure (RFC 5544). Lua

local chilkat = require("chilkat")

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

-- Also see this example:
-- Send a TimeStamp Request to a TimeStamp Authority and get the Response

-- Load a timestamp reply file
local bdTsr = chilkat.BinData.new()
local success = bdTsr:load_file("qa_data/tsd/sample.tsr")
if not success then
    print("Failed to load timestamp reply file.")
    return
end

-- Load the tsr into an ASN.1 object.
local asnTsr = chilkat.Asn.new()
success = asnTsr:load_encoded(bdTsr:get_encoded("base64"), "base64")
if not success then
    print(asnTsr.last_error_text)
    return
end

-- Get the timestamp reply as XML.
local xmlTsr = chilkat.Xml.new()
xmlTsr:load_xml(asnTsr:asn_to_xml())

-- The timestamp reply XML begins like this:
-- We'll want to remove the 1st "sequence" subtree.

--     <?xml version="1.0" encoding="utf-8"?>
--     <sequence>
--         <sequence>       <---- Remove this sub-tree.
--             <int>00</int>
--             <sequence>
--                 <utf8>Operation Okay</utf8>
--             </sequence>
--         </sequence>
--         <sequence>
--             <oid>1.2.840.113549.1.7.2</oid>
--             <contextSpecific tag="0" constructed="1">
--             ...

-- Remove the 1st sub-tree..
xmlTsr:remove_child_by_index(0)

-- In this example, the data file we're combining with the timestamp into a timestampData is a .p7m.
-- However, it can be any type of file (text or binary), it doesn't matter..
local bdContent = chilkat.BinData.new()
success = bdContent:load_file("qa_data/tsd/sample.p7m")
if not success then
    print("Failed to load content file.")
    return
end

-- Begin building the TimeStampData.
-- We'll build as XML and then convert to ASN.1
local xml = chilkat.Xml.new()
xml.tag = "sequence"
xml:update_child_content("oid", "1.2.840.113549.1.9.16.1.31")
xml:update_attr_at("contextSpecific", true, "tag", "0")
xml:update_attr_at("contextSpecific", true, "constructed", "1")
xml:update_child_content("contextSpecific|sequence|int", "01")
xml:update_child_content("contextSpecific|sequence|octets", bdContent:get_encoded("base64"))
xml:update_attr_at("contextSpecific|sequence|contextSpecific", true, "tag", "0")
xml:update_attr_at("contextSpecific|sequence|contextSpecific", true, "constructed", "1")

local xContext = xml:get_child_with_tag("contextSpecific|sequence|contextSpecific")
xContext:add_child_tree(xmlTsr)

-- Convert the XML to ASN.1
local tsd = chilkat.Asn.new()
tsd:load_asn_xml(xml:get_xml())

-- Write the timestamped data to a file.
success = tsd:write_binary_der("qa_output/sample.tsd")

-- Alternatively, get the tsd ASN.1 as base64..
local tsdBase64 = tsd:get_encoded_der("base64_mime")
print(tsdBase64)