Swift

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

See more Encryption Examples

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.

Swift

func chilkatTest() {
    var success: Bool = false

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

    let crypt = CkoCrypt2()!

    // 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).
    let cert1 = CkoCert()!
    success = cert1.load(fromFile: "qa_data/user1/cert_user1.pem")
    // Assume success for the example, but make sure your application checks for success/failure...
    crypt.addEncryptCert(cert: cert1)

    let cert2 = CkoCert()!
    success = cert2.load(fromFile: "qa_data/user2/cert_user2.pem")
    crypt.addEncryptCert(cert: cert2)

    let cert3 = CkoCert()!
    success = cert3.load(fromFile: "qa_data/user3/cert_user3.pem")
    crypt.addEncryptCert(cert: 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.
    crypt.cryptAlgorithm = "pki"
    crypt.pkcs7CryptAlg = "aes"
    crypt.keyLength = 128
    crypt.oaepHash = "sha256"
    crypt.oaepPadding = true

    // Load the file to be encrypted...
    let fileData = CkoBinData()!
    success = fileData.loadFile(path: "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(bd: fileData)
    if success != true {
        print("\(crypt.lastErrorText!)")
        return
    }

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

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

    print("OK.")

}