Verify Java Signature

Demonstrates how to verify a digital signature produced by Java.
The Java code that produces a digital signature that can be verified with
this Chilkat example is found at: http://www.cknotes.com/?p=283

Download 32-bit Chilkat RSA ActiveX (.msi)

Download All 32-bit Chilkat ActiveX Components (.zip)

Download All 64-bit Chilkat ActiveX Components (.zip)

Dim pubKey As New PublicKey

Dim success As Long

'  Load an RSA public key from an ASN.1 DER file
success = pubKey.LoadRsaDerFile("pubKey.der")

If (success <> 1) Then
    Text1.Text = Text1.Text & pubKey.LastErrorText & vbCrLf
    Exit Sub
End If

Dim pkeyXml As String
'  Get the public key in XML format:
pkeyXml = pubKey.GetXml()

Dim rsa As New ChilkatRsa

'  Any string argument automatically begins the 30-day trial.

success = rsa.UnlockComponent("30-day trial")
If (success <> 1) Then
    Text1.Text = Text1.Text & rsa.LastErrorText & vbCrLf
    Exit Sub
End If

'  Import the public key into the RSA component:
success = rsa.ImportPublicKey(pkeyXml)
If (success <> 1) Then
    Text1.Text = Text1.Text & rsa.LastErrorText & vbCrLf
    Exit Sub
End If

rsa.EncodingMode = "base64"

Dim strData As String
strData = "The quick brown fox jumps over the lazy dog"

'  IMPORTANT:  This Base64 signature will have to be updated
'  with the digital signature produced by the Java code at:
'  http://www.cknotes.com/?p=283
Dim base64Sig As String
base64Sig = "VGV5A+bodHBpBwwJZdf17Bv+lkBTm/gteOf8iCgEEfNzBosZLaAB8X55BIZIkE2zKRXoMcJT+iCxsj+1hnlwJeKZ+Gya58lrHw6NWm2N0O/KyfnuEzADOM86X0xrkgdFT6SYpbZ9dWPC59NiHeEdVyjOXNJ3fBpUSQ5/5pvVWm0="

'  Verify the signature produced by the Java code at:
'  http://www.cknotes.com/?p=283
'  The VerifyStringENC method hashes the input data and verifies
'  the hash against the signature.
success = rsa.VerifyStringENC(strData,"sha-1",base64Sig)
'  Is the signature verified?
If (success = 1) Then
    Text1.Text = Text1.Text & "Signature Verified!" & vbCrLf
Else
    Text1.Text = Text1.Text & "Signature not verified!" & vbCrLf
End If