Use Certificate and Private Key PEM Files to Create a Digital Signature

Demonstrates how to load a digital certificate from a PEM file, load it's corresponding private key from a PEM file, save the private key to a key container (if necessary), link the certificate to the key container, and use it to create a digital signature.

Download Chilkat .NET for 4.0 Framework

Download Chilkat .NET for 64-bit 4.0 Framework (x64)

Download Chilkat .NET for 2.0 / 3.5 Framework

Download Chilkat .NET for 64-bit 2.0 / 3.5 Framework (x64)

Download Chilkat .NET for 1.0 / 1.1 Framework

Dim cert As New Chilkat.Cert()

'  Load the cert from a PEM file;
cert.LoadFromFile("cert.pem")

Dim pkey As New Chilkat.PrivateKey()

'  Load the private key from an RSA PEM file:
pkey.LoadPemFile("pkey_rsa.pem")

Dim success As Boolean

success = cert.SetPrivateKey(pkey)
If (success <> true) Then
    TextBox1.Text = TextBox1.Text & cert.LastErrorText & vbCrLf
    Exit Sub
End If


'  Use Chilkat Crypt (a non-freeware component) to create
'  a digital signature using the certificate w/ private key:
Dim crypt As New Chilkat.Crypt2()

'  Any string argument automatically begins the 30-day trial.

success = crypt.UnlockComponent("30-day trial")
If (success <> true) Then
    TextBox1.Text = TextBox1.Text & crypt.LastErrorText & vbCrLf
    Exit Sub
End If


'  Tell the crypt component to use this cert.
crypt.SetSigningCert(cert)

'  A PKCS7 signature for any type of file content can be created:
success = crypt.CreateP7S("license.rtf","license.p7s")
If (success = false) Then
    TextBox1.Text = TextBox1.Text & crypt.LastErrorText & vbCrLf
    Exit Sub
End If

TextBox1.Text = TextBox1.Text & crypt.LastErrorText & vbCrLf

'  Verify and restore the original file:
crypt.SetVerifyCert(cert)

success = crypt.VerifyP7S("license.rtf","license.p7s")
If (success = false) Then
    TextBox1.Text = TextBox1.Text & crypt.LastErrorText & vbCrLf
    Exit Sub
End If


MsgBox("Success!")