Xbase++

Encrypt File to PKCS7 .p7m

See more Encryption Examples

_LANGUAGE_ example to public-key encrypt a file creating a PKCS#7 .p7m file as output. Also demonstrates how to decrypt the .p7m to recover the original file. Xbase++

LOCAL nSuccess
LOCAL oCrypt
LOCAL oEncryptCert
LOCAL cInFile
LOCAL cOutFile
LOCAL oDecrypt
LOCAL cPfxFilename
LOCAL cPfxPassword

nSuccess := 0

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

oCrypt := CreateObject("Chilkat.Crypt2")

//  Indicate the public-key encryption is to be used.
//  Do this by setting the encryption algorithm equal 
//  to "PKI" (an acroynm for public-key infrastructure).
oCrypt:CryptAlgorithm := "PKI"

//  Indicate the inner symmetric encryption algorithm to be used.
//  possible values are "aes", "des", "3des", and "rc2".
//  For this example, we'll use 256-bit AES encryption.
oCrypt:Pkcs7CryptAlg := "aes"
oCrypt:KeyLength := 256

//  To encrypt, only a certificate w/ public key is needed.
//  (The certificate w/ private key is required for decryption.)

//  The LoadFromFile method can load virtually any certificate format:
//  1. DER encoded binary X.509 (.CER)
//  2. Base-64 encoded X.509 (.CER)
//  3. Cryptographic Message Syntax Standard - PKCS #7 Certificates (.P7B)
//  4. PEM format
oEncryptCert := CreateObject("Chilkat.Cert")
nSuccess := oEncryptCert:LoadFromFile("/Users/chilkat/testData/cer/acme.cer")
IF (nSuccess != 1)
    ? oEncryptCert:LastErrorText
    oCrypt:destroy()
    oEncryptCert:destroy()
    RETURN
ENDIF

//  Tell the crypt object to use the certificate for encrypting:
oCrypt:AddEncryptCert(oEncryptCert)

//  Encrypt a file, producing a .p7m as output.
//  The input file is unchanged, the output .p7m contains the encrypted
//  contents of the input file.
cInFile := "/Users/chilkat/testData/pdf/sample.pdf"
cOutFile := "/Users/chilkat/testData/p7m/sample.pdf.p7m"
nSuccess := oCrypt:CkEncryptFile(cInFile, cOutFile)
IF (nSuccess != 1)
    ? oCrypt:LastErrorText
    oCrypt:destroy()
    oEncryptCert:destroy()
    RETURN
ENDIF

//  For demonstration purposes, a different instance of the object will be used
//  for decryption.
oDecrypt := CreateObject("Chilkat.Crypt2")

//  To decrypt, the certificate w/ private key is required.  A PFX (also known
//  as PKCS#12) is a common secure container for certs and private keys.
cPfxFilename := "/Users/chilkat/testData/pfx/acme.pfx"
cPfxPassword := "secret"

//  Tell the component to look in the PFX file for certs and private keys.
nSuccess := oDecrypt:AddPfxSourceFile(cPfxFilename, cPfxPassword)
IF (nSuccess != 1)
    ? oDecrypt:LastErrorText
    oCrypt:destroy()
    oEncryptCert:destroy()
    oDecrypt:destroy()
    RETURN
ENDIF

//  Tell the decrypt object that PKI (public key encryption) is to be used
//  for decryptiong.
oDecrypt:CryptAlgorithm := "PKI"
//  There is no need to set the Pkcs7Alg or KeyLength because this information
//  is contained within the .p7m

//  Decrypt the .p7m
cInFile := "/Users/chilkat/testData/p7m/sample.pdf.p7m"
cOutFile := "/Users/chilkat/testData/pdf/recovered.pdf"
nSuccess := oDecrypt:CkDecryptFile(cInFile, cOutFile)
IF (nSuccess == 0)
    ? oDecrypt:LastErrorText
    oCrypt:destroy()
    oEncryptCert:destroy()
    oDecrypt:destroy()
    RETURN
ENDIF

? "Success!"

oCrypt:destroy()
oEncryptCert:destroy()
oDecrypt:destroy()