(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.

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

LOCAL loRsa
LOCAL lnSuccess
LOCAL lcStrData
LOCAL lcHexSig

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

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Rsa')
loRsa = CreateObject('Chilkat.Rsa')

* Generate a 2048-bit RSA key.
lnSuccess = loRsa.GenerateKey(2048)

* 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
? loRsa.LastErrorText

* Now verify the signature:
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
    ? loRsa.LastErrorText
ENDIF

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

* Try it with the wrong hash algorithm:
lnSuccess = loRsa.VerifyStringENC(lcStrData,"sha-1",lcHexSig)
IF (lnSuccess = 1) THEN
    ? "Signature verified!"
ELSE
    ? loRsa.LastErrorText
ENDIF

RELEASE loRsa