(Visual FoxPro) Generate RSA Key and Sign a String

See more RSA Examples

Demonstrates how to generate a new RSA public/private key pair and use it to generate a signature for a string. The (binary) digital signature is returned as a hexidecimalized string.

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

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ActiveX for 32-bit and 64-bit Windows

LOCAL lnSuccess
LOCAL loRsa
LOCAL loPrivKey
LOCAL lcStrData
LOCAL lcHexSig
LOCAL loPubKey

lnSuccess = 0

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

loRsa = CreateObject('Chilkat.Rsa')

* Generate a 2048-bit RSA key.
loPrivKey = CreateObject('Chilkat.PrivateKey')
lnSuccess = loRsa.GenKey(2048,loPrivKey)

loRsa.UsePrivateKey(loPrivKey)

* Return the signature in hex.
loRsa.EncodingMode = "hex"

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

* Sign the SHA256 hash of the string.
lcHexSig = loRsa.SignStringENC(lcStrData,"sha256")

? lcHexSig

* Now verify the signature:
loPubKey = CreateObject('Chilkat.PublicKey')
loPrivKey.ToPublicKey(loPubKey)
loRsa.UsePublicKey(loPubKey)

lnSuccess = loRsa.VerifyStringENC(lcStrData,"sha256",lcHexSig)
IF (lnSuccess = 1) THEN
    ? "Signature verified!"
ELSE
    ? loRsa.LastErrorText
ENDIF

* Try it with an invalid signature:
lnSuccess = loRsa.VerifyStringENC(lcStrData,"sha256","not a valid sig")
IF (lnSuccess = 1) THEN
    ? "Signature verified!"
ELSE
    ? "Signature validation failed!"
ENDIF

* Try it with invalid data:
lnSuccess = loRsa.VerifyStringENC("Not the original data","sha256",lcHexSig)
IF (lnSuccess = 1) THEN
    ? "Signature verified!"
ELSE
    ? "Signature validation failed!"
ENDIF

RELEASE loRsa
RELEASE loPrivKey
RELEASE loPubKey