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)

LOCAL loPubKey
LOCAL lnSuccess
LOCAL lcPkeyXml
LOCAL loRsa
LOCAL lcStrData
LOCAL lcBase64Sig


loPubKey = CreateObject('Chilkat.PublicKey')

*  Load an RSA public key from an ASN.1 DER file
lnSuccess = loPubKey.LoadRsaDerFile("pubKey.der")

IF (lnSuccess <> 1) THEN
    ? loPubKey.LastErrorText
    QUIT
ENDIF

*  Get the public key in XML format:
lcPkeyXml = loPubKey.GetXml()

loRsa = CreateObject('Chilkat.Rsa')

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

lnSuccess = loRsa.UnlockComponent("30-day trial")
IF (lnSuccess <> 1) THEN
    ? loRsa.LastErrorText
    QUIT
ENDIF

*  Import the public key into the RSA component:
lnSuccess = loRsa.ImportPublicKey(lcPkeyXml)
IF (lnSuccess <> 1) THEN
    ? loRsa.LastErrorText
    QUIT
ENDIF

loRsa.EncodingMode = "base64"

lcStrData = "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

lcBase64Sig = "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.
lnSuccess = loRsa.VerifyStringENC(lcStrData,"sha-1",lcBase64Sig)
*  Is the signature verified?
IF (lnSuccess = 1) THEN
    ? "Signature Verified!"
ELSE
    ? "Signature not verified!"
ENDIF