Lua

Convert Let's Encrypt PEM Files to a PFX

See more PFX/P12 Examples

Demonstrates how to convert the .pem files provided by Let's Encrypt to a single PFX. Lua

local chilkat = require("chilkat")

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

-- Let's Encrypt provides four .pem files
-- 1. fullchain.pem
-- 2. privkey.pem
-- 3. cert.pem
-- 4. chain.pem

-- The cert.pem and chain.pem are redundant.
-- The fullchain.pem is composed of the cert.pem and chain.pem.

-- To convert the PEM's to a single .pfx, we don't need the redundant data.
-- The privkey.pem and fullchain.pem provide the required data.
-- We can ignore cert.pem and chain.pem (because those certs are already found in fullchain.pem).

-- We need a single .pem file that contains both the private key, the cert,
-- and the certs in the chain of authentication.
-- Let's combine priveky.pem and fullchain.pem into a single .pem

local sbPem = chilkat.StringBuilder.new()
local success = sbPem:load_file("qa_data/pem/lets_encrypt/privkey.pem", "utf-8")
if not success then
    print("Failed to load privkey.pem")
    return
end

-- To be safe, append a blank line..
sbPem:append_line("", false)

local sbFullChainPem = chilkat.StringBuilder.new()
success = sbFullChainPem:load_file("qa_data/pem/lets_encrypt/fullchain.pem", "utf-8")
if not success then
    print("Failed to load fullchain.pem")
    return
end

-- Append the full cert chain PEM to the private key PEM.
sbPem:append_sb(sbFullChainPem)

-- Load the combined PEM into a Chilkat PFX object.
local pfx = chilkat.Pfx.new()
success = pfx:load_pem(sbPem:get_as_string(), "no password required")
if not success then
    print(pfx.last_error_text)
    return
end

-- Write the PFX w/ a password.
local pfxPassword = "secret"
success = pfx:to_file(pfxPassword, "qa_output/sample.pfx")
if not success then
    print(pfx.last_error_text)
    return
end

print("Success!")