(Visual FoxPro) Sign JSON to Create CAdES P7S Bytes

Demonstrates how to sign JSON using a certificate + private key from a .p12/.pfx to create a CAdES P7S byte array.

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

LOCAL loCrypt
LOCAL loCert
LOCAL lnSuccess
LOCAL loJsonSigningAttrs
LOCAL loCadesP7s
LOCAL lcOriginalJson

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

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Crypt2')
loCrypt = CreateObject('Chilkat.Crypt2')

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Cert')
loCert = CreateObject('Chilkat.Cert')
lnSuccess = loCert.LoadPfxFile("qa_data/pfx/cert_test123.pfx","test123")
IF (lnSuccess <> 1) THEN
    ? loCert.LastErrorText
    RELEASE loCrypt
    RELEASE loCert
    CANCEL
ENDIF

* Tell the crypt component to use this cert.
lnSuccess = loCrypt.SetSigningCert(loCert)
IF (lnSuccess <> 1) THEN
    ? loCrypt.LastErrorText
    RELEASE loCrypt
    RELEASE loCert
    CANCEL
ENDIF

* The CadesEnabled property applies to all methods that create PKCS7 signatures. 
* To create a CAdES-BES signature, set this property equal to true. 
loCrypt.CadesEnabled = 1

loCrypt.HashAlgorithm = "sha256"

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJsonSigningAttrs = CreateObject('Chilkat.JsonObject')
loJsonSigningAttrs.UpdateInt("contentType",1)
loJsonSigningAttrs.UpdateInt("signingTime",1)
loJsonSigningAttrs.UpdateInt("messageDigest",1)
loJsonSigningAttrs.UpdateInt("signingCertificateV2",1)
loCrypt.SigningAttributes = loJsonSigningAttrs.Emit()

* By default, all the certs in the chain of authentication are included in the signature.
* If desired, we can choose to only include the signing certificate:
loCrypt.IncludeCertChain = 0

* Create the CAdES-BES attached signature, which contains the original data.
loCrypt.Charset = "utf-8"

loCadesP7s = loCrypt.OpaqueSignString('{ "abc": 123}')
IF (loCrypt.LastMethodSuccess = 0) THEN
    ? loCrypt.LastErrorText
    RELEASE loCrypt
    RELEASE loCert
    RELEASE loJsonSigningAttrs
    CANCEL
ENDIF

* Verify the signature and extract the original JSON:
lcOriginalJson = loCrypt.OpaqueVerifyString(loCadesP7s)
IF (loCrypt.LastMethodSuccess = 0) THEN
    ? loCrypt.LastErrorText
    RELEASE loCrypt
    RELEASE loCert
    RELEASE loJsonSigningAttrs
    CANCEL
ENDIF

? "Original JSON: " + lcOriginalJson

? "Success!"

RELEASE loCrypt
RELEASE loCert
RELEASE loJsonSigningAttrs