PowerBuilder

Encrypt a File to a PKCS7 (CMS) Message

Shows how to encrypt a file into a PKCS7 encrypted message using the recipient's certificate. Public-key encryption requires no private key. However, the recipient's private key is necessary for decryption. PowerBuilder

integer li_rc
integer li_Success
oleobject loo_Crypt
oleobject loo_Cert1
oleobject loo_FileData

li_Success = 0

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

loo_Crypt = create oleobject
li_rc = loo_Crypt.ConnectToNewObject("Chilkat.Crypt2")
if li_rc < 0 then
    destroy loo_Crypt
    MessageBox("Error","Connecting to COM object failed")
    return
end if

// Load the recipient's digital certificate. 
// We don't need the private key for encryption.
// Only the public key is needed (which is included in a certificate).
loo_Cert1 = create oleobject
li_rc = loo_Cert1.ConnectToNewObject("Chilkat.Cert")

li_Success = loo_Cert1.LoadFromFile("qa_data/user1/cert_user1.pem")
// Assume success for the example, but make sure your application checks for success/failure...
loo_Crypt.SetEncryptCert(loo_Cert1)

// Indicate that we want PKI encryption (i.e. public-key infrastructure)
// to produce a CMS message (Cryptographic Message Syntax/PKCS7),
// that is be created with RSAES-OAEP padding, SHA256, and AES-256 for the
// bulk encryption.
loo_Crypt.CryptAlgorithm = "pki"
loo_Crypt.Pkcs7CryptAlg = "aes"
loo_Crypt.KeyLength = 256
loo_Crypt.OaepHash = "sha256"
loo_Crypt.OaepPadding = 1

// Load the file to be encrypted...
loo_FileData = create oleobject
li_rc = loo_FileData.ConnectToNewObject("Chilkat.BinData")

li_Success = loo_FileData.LoadFile("qa_data/jpg/penguins.jpg")
// Your app should check for success/failure..

// Encrypt the data.  The contents of the fileData object are replaced with the PKCS7 encrypted message.
li_Success = loo_Crypt.EncryptBd(loo_FileData)
if li_Success <> 1 then
    Write-Debug loo_Crypt.LastErrorText
    destroy loo_Crypt
    destroy loo_Cert1
    destroy loo_FileData
    return
end if

// Save the PKCS7 encrypted message to a file..
li_Success = loo_FileData.WriteFile("qa_output/pkcs7_encrypted.p7")

Write-Debug "OK."


destroy loo_Crypt
destroy loo_Cert1
destroy loo_FileData