(PowerBuilder) Encrypt a file to a PKCS7 encrypted message using multiple certificates from different users

Demonstrates how to encrypt a file to a PKCS7 encrypted message using multiple certificates from different users. Any one of the users can decrypt using his/her own certificate + private key.

Note: When doing public key encryption, it is the public key that is used to encrypt. The private key is required for decryption.

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

integer li_rc
oleobject loo_Crypt
oleobject loo_Cert1
integer li_Success
oleobject loo_Cert2
oleobject loo_Cert3
oleobject loo_FileData

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

loo_Crypt = create oleobject
li_rc = loo_Crypt.ConnectToNewObject("Chilkat_9_5_0.Crypt2")
if li_rc < 0 then
    destroy loo_Crypt
    MessageBox("Error","Connecting to COM object failed")
    return
end if

//  Tell the crypt object to use 3 certificates.
//  Do this by calling AddEncryptCert for each certificate.

//  Load a 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_9_5_0.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.AddEncryptCert(loo_Cert1)

loo_Cert2 = create oleobject
li_rc = loo_Cert2.ConnectToNewObject("Chilkat_9_5_0.Cert")

li_Success = loo_Cert2.LoadFromFile("qa_data/user2/cert_user2.pem")
loo_Crypt.AddEncryptCert(loo_Cert2)

loo_Cert3 = create oleobject
li_rc = loo_Cert3.ConnectToNewObject("Chilkat_9_5_0.Cert")

li_Success = loo_Cert3.LoadFromFile("qa_data/user3/cert_user3.pem")
loo_Crypt.AddEncryptCert(loo_Cert3)

//  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-128 for the
//  bulk encryption.
loo_Crypt.CryptAlgorithm = "pki"
loo_Crypt.Pkcs7CryptAlg = "aes"
loo_Crypt.KeyLength = 128
loo_Crypt.OaepHash = "sha256"
loo_Crypt.OaepPadding = 1

//  Load the file to be encrypted...
loo_FileData = create oleobject
li_rc = loo_FileData.ConnectToNewObject("Chilkat_9_5_0.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_Cert2
    destroy loo_Cert3
    destroy loo_FileData
    return
end if

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

//  Now indicate that the PKCS7 output is to be returned in the base64 encoding.
loo_Crypt.EncodingMode = "base64"

Write-Debug "OK."


destroy loo_Crypt
destroy loo_Cert1
destroy loo_Cert2
destroy loo_Cert3
destroy loo_FileData