VBScript

Load .eml and Decrypt (smime.p7m)

Loads an encrypted email from a .eml file and decrypts using certificate w/ private key found in a .p12 (or .pfx) file.

The Content-Type and Content-Disposition email headers of the email to be decrypted look similar to this:

Content-Type: application/x-pkcs7-mime; smime-type=enveloped-data;
	name="smime.p7m"
Content-Disposition: attachment; filename="smime.p7m"

VBScript

Dim fso, outFile
Set fso = CreateObject("Scripting.FileSystemObject")
'Create a Unicode (utf-16) output text file.
Set outFile = fso.CreateTextFile("output.txt", True, True)

success = 0

set email = CreateObject("Chilkat.Email")

' Add a PFX (or .p12) to be used for decryption
success = email.AddPfxSourceFile("myCert.p12","passwordForP12")
If (success <> 1) Then
    outFile.WriteLine(email.LastErrorText)
    WScript.Quit
End If

' Loading the .eml automatically decrypts.
success = email.LoadEml("encrypted.eml")
If (success <> 1) Then
    outFile.WriteLine(email.LastErrorText)
    WScript.Quit
End If

' The email now exists as it was prior to encryption.
' Your app may access the email's subject, body, attachments,
' etc. using the Chilkat Email API...

' Save the decrypted email:
success = email.SaveEml("decrypted.eml")
If (success <> 1) Then
    outFile.WriteLine(email.LastErrorText)
    WScript.Quit
End If

outFile.WriteLine("Success.")

outFile.Close