Visual Basic 6.0

Duplicate OpensSSL Command that Decrypts Binary DER

See more OpenSSL Examples

This example duplicates the following:

openssl smime -decrypt -in INPUT_FILE -inform der -binary -out OUTPUT_FILE -recip PEM_CERT_AND_KEY -passin pass:PRIVKEY_PASSWORD

Note: Although "smime" is the OpenSSL command, we're not really dealing with S/MIME. The arguments "-inform der -binary" indicate that the input is simply the binary DER (i.e. the PKCS7 binary encrypted object). The output can be any type of file (whatever was encrypted).

Visual Basic 6.0

Dim success As Long
success = 0

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

Dim crypt As New ChilkatCrypt2

crypt.CryptAlgorithm = "pki"

Dim pem As New ChilkatPem
success = pem.LoadPemFile("qa_data/pem/myPem.pem","password")
If (success = 0) Then
    Debug.Print pem.LastErrorText
    Exit Sub
End If

Dim privkey As New PrivateKey
success = pem.PrivateKeyAt(0,privkey)
If (success = 0) Then
    Debug.Print pem.LastErrorText
    Exit Sub
End If

Dim cert As New ChilkatCert
success = pem.CertAt(0,cert)
If (success = 0) Then
    Debug.Print pem.LastErrorText
    Exit Sub
End If

success = crypt.SetDecryptCert2(cert,privkey)
If (success = 0) Then
    Debug.Print crypt.LastErrorText
    Exit Sub
End If

success = crypt.CkDecryptFile("qa_data/infile.enc","qa_output/outfile.dat")
If (success = 0) Then
    Debug.Print crypt.LastErrorText
    Exit Sub
End If

Debug.Print "Success."