(Visual Basic 6.0) Decrypt a .p7m File (using a PFX)

Visual Basic 6.0 sample code showing how to decrypt a .p7m using a .p12 / .pfx certificate w/ private key.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

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

Dim crypt As New ChilkatCrypt2

' Use a digital certificate and private key from a PFX file (.pfx or .p12).
Dim pfxPath As String
pfxPath = "myCertAndKey.pfx"
Dim pfxPassword As String
pfxPassword = "test123"

Dim success As Long
success = crypt.AddPfxSourceFile(pfxPath,pfxPassword)
If (success <> 1) Then
    Debug.Print crypt.LastErrorText
    Exit Sub
End If

' Set the  outPath to whatever is appropriate.
' If you are decrypting a PDF, your output might be "out.pdf"...
Dim inPath As String
inPath = "smime.p7m"
Dim outPath As String
outPath = "original.txt"

' Indicate that we're doing public key decryption (i.e. PKCS7)
crypt.CryptAlgorithm = "pki"

success = crypt.CkDecryptFile(inPath,outPath)
If (success = 0) Then
    Debug.Print crypt.LastErrorText
    Exit Sub
End If

Debug.Print "Success."