(Lianja) 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 Lianja Extension Download Chilkat Lianja Extension

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

loCrypt = createobject("CkCrypt2")

loCert = createobject("CkCert")
llSuccess = loCert.LoadPfxFile("qa_data/pfx/cert_test123.pfx","test123")
if (llSuccess <> .T.) then
    ? loCert.LastErrorText
    release loCrypt
    release loCert
    return
endif

// Tell the crypt component to use this cert.
llSuccess = loCrypt.SetSigningCert(loCert)
if (llSuccess <> .T.) then
    ? loCrypt.LastErrorText
    release loCrypt
    release loCert
    return
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 = .T.

loCrypt.HashAlgorithm = "sha256"

loJsonSigningAttrs = createobject("CkJsonObject")
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 = .F.

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

loCadesP7s = loCrypt.OpaqueSignString('{ "abc": 123}')
if (loCrypt.LastMethodSuccess = .F.) then
    ? loCrypt.LastErrorText
    release loCrypt
    release loCert
    release loJsonSigningAttrs
    return
endif

// Verify the signature and extract the original JSON:
lcOriginalJson = loCrypt.OpaqueVerifyString(loCadesP7s)
if (loCrypt.LastMethodSuccess = .F.) then
    ? loCrypt.LastErrorText
    release loCrypt
    release loCert
    release loJsonSigningAttrs
    return
endif

? "Original JSON: " + lcOriginalJson

? "Success!"


release loCrypt
release loCert
release loJsonSigningAttrs