Go

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. Go

    success := false

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

    crypt := chilkat.NewCrypt2()

    // 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).
    cert1 := chilkat.NewCert()
    success = cert1.LoadFromFile("qa_data/user1/cert_user1.pem")
    // Assume success for the example, but make sure your application checks for success/failure...
    crypt.SetEncryptCert(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.
    crypt.SetCryptAlgorithm("pki")
    crypt.SetPkcs7CryptAlg("aes")
    crypt.SetKeyLength(256)
    crypt.SetOaepHash("sha256")
    crypt.SetOaepPadding(true)

    // Load the file to be encrypted...
    fileData := chilkat.NewBinData()
    success = 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.
    success = crypt.EncryptBd(fileData)
    if success != true {
        fmt.Println(crypt.LastErrorText())
        crypt.DisposeCrypt2()
        cert1.DisposeCert()
        fileData.DisposeBinData()
        return
    }

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

    fmt.Println("OK.")

    crypt.DisposeCrypt2()
    cert1.DisposeCert()
    fileData.DisposeBinData()