B4X

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. B4X

Dim success As Boolean = False

'  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

Dim sbPem As ChilkatStringBuilder
sbPem.Initialize
success = sbPem.LoadFile("qa_data/pem/lets_encrypt/privkey.pem", "utf-8")
If success = False Then
    Log("Failed to load privkey.pem")
    Return
End If


'  To be safe, append a blank line..
sbPem.AppendLine("", False)

Dim sbFullChainPem As ChilkatStringBuilder
sbFullChainPem.Initialize
success = sbFullChainPem.LoadFile("qa_data/pem/lets_encrypt/fullchain.pem", "utf-8")
If success = False Then
    Log("Failed to load fullchain.pem")
    Return
End If


'  Append the full cert chain PEM to the private key PEM.
sbPem.AppendSb(sbFullChainPem)

'  Load the combined PEM into a Chilkat PFX object.
Dim pfx As ChilkatPfx
pfx.Initialize
success = pfx.LoadPem(sbPem.GetAsString, "no password required")
If success = False Then
    Log(pfx.LastErrorText)
    Return
End If


'  Write the PFX w/ a password.
Dim pfxPassword As String = "secret"
success = pfx.ToFile(pfxPassword, "qa_output/sample.pfx")
If success = False Then
    Log(pfx.LastErrorText)
    Return
End If


Log("Success!")