(PowerBuilder) Duplicate openssl dgst -sha256 -verify pubKey.pem -signature signature.sig in.dat

Demonstrates how to duplicate this OpenSSL command:

openssl dgst -sha256 -verify pubKey.pem -signature signature.sig in.dat

The in.dat file contains the original data that was signed, and can contain text or binary data of any type. The above OpenSSL command does the following:

Creates a SHA256 digest of the contents of the input file.
Verifies the SHA256 digest using the public key.

Chilkat ActiveX Downloads

ActiveX for 32-bit and 64-bit Windows

integer li_rc
oleobject loo_PubKey
integer li_Success
oleobject loo_BdFileData
oleobject loo_BdSig
oleobject loo_Rsa

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

loo_PubKey = create oleobject
// Use "Chilkat_9_5_0.PublicKey" for versions of Chilkat < 10.0.0
li_rc = loo_PubKey.ConnectToNewObject("Chilkat.PublicKey")
if li_rc < 0 then
    destroy loo_PubKey
    MessageBox("Error","Connecting to COM object failed")
    return
end if

// Load the public key from an PEM file:
li_Success = loo_PubKey.LoadFromFile("pubKey.pem")
if li_Success <> 1 then
    Write-Debug loo_PubKey.LastErrorText
    destroy loo_PubKey
    return
end if

// Load the data of the original file that was signed.
loo_BdFileData = create oleobject
// Use "Chilkat_9_5_0.BinData" for versions of Chilkat < 10.0.0
li_rc = loo_BdFileData.ConnectToNewObject("Chilkat.BinData")

li_Success = loo_BdFileData.LoadFile("in.dat")

// Load the signature.
loo_BdSig = create oleobject
// Use "Chilkat_9_5_0.BinData" for versions of Chilkat < 10.0.0
li_rc = loo_BdSig.ConnectToNewObject("Chilkat.BinData")

li_Success = loo_BdSig.LoadFile("signature.sig")

loo_Rsa = create oleobject
// Use "Chilkat_9_5_0.Rsa" for versions of Chilkat < 10.0.0
li_rc = loo_Rsa.ConnectToNewObject("Chilkat.Rsa")

// Import the public key into the RSA component:
li_Success = loo_Rsa.ImportPublicKeyObj(loo_PubKey)
if li_Success <> 1 then
    Write-Debug loo_Rsa.LastErrorText
    destroy loo_PubKey
    destroy loo_BdFileData
    destroy loo_BdSig
    destroy loo_Rsa
    return
end if

// OpenSSL uses big-endian.
loo_Rsa.LittleEndian = 0

li_Success = loo_Rsa.VerifyBd(loo_BdFileData,"sha256",loo_BdSig)
if li_Success <> 1 then
    Write-Debug loo_Rsa.LastErrorText
    Write-Debug "The signature was invalid."
    destroy loo_PubKey
    destroy loo_BdFileData
    destroy loo_BdSig
    destroy loo_Rsa
    return
end if

Write-Debug "The signature was verified."


destroy loo_PubKey
destroy loo_BdFileData
destroy loo_BdSig
destroy loo_Rsa