(Visual FoxPro) Create PKCS7 (CMS) EnvelopedData

Encrypt some data to a recipient by creating a PKCS7 (CMS) EnvelopedData structure. The data will be encrypted using a symmetric content-encryption algorithm (e.g., AES), and the randomly generated symmetric key will be encrypted using the recipient’s RSA public key extracted from their X.509 certificate.

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

LOCAL loCrypt
LOCAL loCert
LOCAL lnSuccess
LOCAL lcToBeEncrypted
LOCAL lcResult

loCrypt = CreateObject('Chilkat.Crypt2')

* Specify the encryption to be used.
* "pki" indicates "Public Key Infrastructure" and will create a PKCS7 encrypted (enveloped-data) message.
loCrypt.CryptAlgorithm = "pki"
loCrypt.Pkcs7CryptAlg = "aes"
loCrypt.KeyLength = 256
loCrypt.OaepHash = "sha256"
loCrypt.OaepPadding = 1

loCert = CreateObject('Chilkat.Cert')

* Use a certificate found in the Windows certificate store.
lnSuccess = loCert.LoadByCommonName("My Certificate")
IF (lnSuccess <> 1) THEN
    ? loCert.LastErrorText
    RELEASE loCrypt
    RELEASE loCert
    CANCEL
ENDIF

* Tell the crypt object to use the certificate.
loCrypt.SetEncryptCert(loCert)

lcToBeEncrypted = "This string is to be encrypted."

* Get the result in multi-line BASE64 MIME format.
loCrypt.EncodingMode = "base64_mime"
loCrypt.Charset = "utf-8"

lcResult = loCrypt.EncryptStringENC(lcToBeEncrypted)
IF (lnSuccess <> 1) THEN
    ? loCrypt.LastErrorText
    RELEASE loCrypt
    RELEASE loCert
    CANCEL
ENDIF

* -------------------------------------------------------------------------
* See the following example to decrypt what was created in this example
* Decrypt PKCS7 (CMS) EnvelopedData
* -------------------------------------------------------------------------

? lcResult

* Sample output:

* MIICSgYJKoZIhvcNAQcDoIICOzCCAjcCAQAxggHiMIIB3gIBADCBljCBgTELMAkGA1UEBhMCSVQx
* EDAOBgNVBAgMB0JlcmdhbW8xGTAXBgNVBAcMEFBvbnRlIFNhbiBQaWV0cm8xFzAVBgNVBAoMDkFj
* dGFsaXMgUy5wLkEuMSwwKgYDVQQDDCNBY3RhbGlzIENsaWVudCBBdXRoZW50aWNhdGlvbiBDQSBH
* MwIQPCWvkSv8oQ7xRmEHJ6TzEDA8BgkqhkiG9w0BAQcwL6APMA0GCWCGSAFlAwQCAQUAoRwwGgYJ
* KoZIhvcNAQEIMA0GCWCGSAFlAwQCAQUABIIBAKqHAPQNSsQoX7B2NH7QyEOWQRsSVs8oCHXmy8f4
* MVZD2er3bvYUCIomxpwbLEAl14qjUIMynahooYGgqip7+4FqL301G+BVjZVfEhHWj+VI1dAWnWuL
* VHlvc/pbQNBWqV8rKVJsNIsuAZkdj4WSwLVKxYkYX43B8fh/g71XN2DTJu7Z/824v48KBmgpQBOT
* 2q7IcDGxNPAFN2p6eavIVGn2LvhEbf/Fszyj+GR5tMcnQP1BOLJ3s3JzUBbvj8hcZrF1Vhl9HnTU
* YQx8G/KdW1mR+Wlhl3BWoK0LYKRTbnTx2BXOs0CY1SXOAdhKr01ZYjA+xW4nGzY0lfXS9QZjh9gw
* TAYJKoZIhvcNAQcBMB0GCWCGSAFlAwQBKgQQw0xTbfmnt0zjWHo5SaQIp4AgxTVY9E/Ncqy6t+RM
* 8y4c3Av62/wB8IpPUEmtM2OeuZo=

RELEASE loCrypt
RELEASE loCert