Lua

Export a Public Key as DER into a BinData

Demonstrates the Chilkat PublicKey.GetDerBd method, which writes the public key as binary DER into a BinData. The first argument selects the representation (as for GetPem) and the second is the BinData that receives the bytes (its contents are replaced).

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: The in-memory binary export: the raw DER lands in a BinData ready to hash, transmit, or hand to another API without a temporary file. It is the BinData counterpart to the text exporters, and the first argument picks the same PKCS #1 versus SubjectPublicKeyInfo structure.

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Lua

local chilkat = require("chilkat")

-- Load a public key to export.  LoadFromFile inspects the content, so it accepts DER, PEM, XML,
-- JWK, and other supported representations.
local pubKey = chilkat.PublicKey.new()
local success = pubKey:load_from_file("qa_data/public.pem")
if not success then
    print(pubKey.last_error_text)
    return
end

-- Write the public key as binary DER into a BinData.  The 1st argument selects the representation
-- (as for GetPem) and the 2nd is the BinData that receives the bytes (its contents are replaced).
local preferPkcs1 = false
local bd = chilkat.BinData.new()
success = pubKey:get_der_bd(preferPkcs1, bd)
if not success then
    print(pubKey.last_error_text)
    return
end

print("Exported " .. bd.num_bytes .. " DER bytes.")