(Xojo Plugin) Sign JSON (or any Text) to Create a Detached PKCS7 Signature

Demonstrates how to sign JSON or any string using a certificate + private key from a .p12/.pfx to create a detached PKCS7 signature. (A detached signature is one that does not embed the original signed data.)

Chilkat Xojo Plugin Download Xojo Plugin for Windows, Linux, Mac OS X, and ARM, ARM64

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

Dim crypt As New Chilkat.Crypt2

Dim cert As New Chilkat.Cert
Dim success As Boolean
success = cert.LoadPfxFile("qa_data/pfx/cert_test123.pfx","test123")
If (success <> True) Then
    System.DebugLog(cert.LastErrorText)
    Return
End If

// Tell the crypt component to use this cert.
success = crypt.SetSigningCert(cert)
If (success <> True) Then
    System.DebugLog(crypt.LastErrorText)
    Return
End If

crypt.HashAlgorithm = "sha256"

// 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:
crypt.IncludeCertChain = False

// Create the detached signature, which does NOT contain the original data.
// To create a PKCS7 signature that contains the original data, see CAdES Sign JSON
crypt.Charset = "utf-8"
Dim detachedSig As MemoryBlock
Dim stringToSign As String
stringToSign = "{ ""abc"": 123}"
detachedSig = crypt.SignString(stringToSign)
If (crypt.LastMethodSuccess = False) Then
    System.DebugLog(crypt.LastErrorText)
    Return
End If

// Verify the signature against the original data.
Dim verified As Boolean
verified = crypt.VerifyString(stringToSign,detachedSig)
If (verified = False) Then
    System.DebugLog(crypt.LastErrorText)
    Return
End If

System.DebugLog("Success!")