(PowerBuilder) RSA Sign with PKCS8 Encrypted Key

Demonstrates how to load a private key from an encrypted PKCS8 file and create an RSA digital signature (and then verify it).

Note: This example requires Chilkat v11.0.0 or greater.

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

integer li_rc
integer li_Success
oleobject loo_PrivKey
oleobject loo_Rsa
string ls_StrData
string ls_HexSig
oleobject loo_Cert
oleobject loo_PubKey
oleobject loo_Rsa2

li_Success = 0

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

loo_PrivKey = create oleobject
li_rc = loo_PrivKey.ConnectToNewObject("Chilkat.PrivateKey")
if li_rc < 0 then
    destroy loo_PrivKey
    MessageBox("Error","Connecting to COM object failed")
    return
end if

// Load the private key from an RSA PEM file:
li_Success = loo_PrivKey.LoadAnyFormatFile("raul_privateKey.key","a0123456789")
if li_Success = 0 then
    Write-Debug loo_PrivKey.LastErrorText
    destroy loo_PrivKey
    return
end if

loo_Rsa = create oleobject
li_rc = loo_Rsa.ConnectToNewObject("Chilkat.Rsa")

// Import the private key into the RSA component:
li_Success = loo_Rsa.UsePrivateKey(loo_PrivKey)
if li_Success = 0 then
    Write-Debug loo_Rsa.LastErrorText
    destroy loo_PrivKey
    destroy loo_Rsa
    return
end if

// This example will sign a string, and receive the signature
// in a hex-encoded string.  Therefore, set the encoding mode
// to "hex":
loo_Rsa.EncodingMode = "hex"

ls_StrData = "This is the string to be signed."

// Sign the string using the sha256 hash algorithm.
// Other valid choices are sha1, sha384, sha512 and others.
ls_HexSig = loo_Rsa.SignStringENC(ls_StrData,"sha256")
if loo_Rsa.LastMethodSuccess = 0 then
    Write-Debug loo_Rsa.LastErrorText
    destroy loo_PrivKey
    destroy loo_Rsa
    return
end if

Write-Debug ls_HexSig

// Now verify with the public key.
// This example shows how to use the public key from 
// a digital certificate (.cer file)
loo_Cert = create oleobject
li_rc = loo_Cert.ConnectToNewObject("Chilkat.Cert")

li_Success = loo_Cert.LoadFromFile("raul_publicKey.cer")
if li_Success = 0 then
    Write-Debug loo_Cert.LastErrorText
    destroy loo_PrivKey
    destroy loo_Rsa
    destroy loo_Cert
    return
end if

loo_PubKey = create oleobject
li_rc = loo_PubKey.ConnectToNewObject("Chilkat.PublicKey")

loo_Cert.GetPublicKey(loo_PubKey)

loo_Rsa2 = create oleobject
li_rc = loo_Rsa2.ConnectToNewObject("Chilkat.Rsa")

li_Success = loo_Rsa2.UsePublicKey(loo_PubKey)
if li_Success = 0 then
    Write-Debug loo_Rsa2.LastErrorText
    destroy loo_PrivKey
    destroy loo_Rsa
    destroy loo_Cert
    destroy loo_PubKey
    destroy loo_Rsa2
    return
end if

// Verify the signature against the original data:
loo_Rsa2.EncodingMode = "hex"
li_Success = loo_Rsa2.VerifyStringENC(ls_StrData,"sha256",ls_HexSig)
if li_Success = 0 then
    Write-Debug loo_Rsa2.LastErrorText
    destroy loo_PrivKey
    destroy loo_Rsa
    destroy loo_Cert
    destroy loo_PubKey
    destroy loo_Rsa2
    return
end if

Write-Debug "Signature verified!"

// Verify with incorrect data:
li_Success = loo_Rsa2.VerifyStringENC("something else","sha256",ls_HexSig)
if li_Success <> 1 then
    Write-Debug "Signature not verified! (which was expected in this case)"
else
    Write-Debug "Hmmm... that's not right..."
end if



destroy loo_PrivKey
destroy loo_Rsa
destroy loo_Cert
destroy loo_PubKey
destroy loo_Rsa2