Xbase++ Requires Chilkat v11.0.0+

RSA Signature/Verify with .key and .cer

See more RSA Examples

Demonstrates how to use a .key file (private key) and digital certificate (.cer, public key) to create and verify an RSA signature. Xbase++

LOCAL nSuccess
LOCAL oPrivKey
LOCAL oRsa
LOCAL cStrData
LOCAL cHexSig
LOCAL oCert
LOCAL oPubKey
LOCAL oRsa2

nSuccess := 0

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

oPrivKey := CreateObject("Chilkat.PrivateKey")

//  Load the private key from an RSA .key file:
nSuccess := oPrivKey:LoadPemFile("privateKey.key")
IF (nSuccess == 0)
    ? oPrivKey:LastErrorText
    oPrivKey:destroy()
    RETURN
ENDIF

oRsa := CreateObject("Chilkat.Rsa")

//  Import the private key into the RSA component:
nSuccess := oRsa:UsePrivateKey(oPrivKey)
IF (nSuccess == 0)
    ? oRsa:LastErrorText
    oPrivKey:destroy()
    oRsa:destroy()
    RETURN
ENDIF

//  Create the signature as a hex string:
oRsa:EncodingMode := "hex"

cStrData := "This is the string to be signed."

//  Sign the string using the sha256 hash algorithm.
//  Other valid choices are "md2", "sha1", "sha384",
//  "sha512", and "md5".
cHexSig := oRsa:SignStringENC(cStrData, "sha256")

? cHexSig

//  Load a digital certificate from a .cer file:
oCert := CreateObject("Chilkat.Cert")

nSuccess := oCert:LoadFromFile("myCert.cer")
IF (nSuccess == 0)
    ? oCert:LastErrorText
    oPrivKey:destroy()
    oRsa:destroy()
    oCert:destroy()
    RETURN
ENDIF

oPubKey := CreateObject("Chilkat.PublicKey")
oCert:GetPublicKey(oPubKey)

//  Now verify using a new instance of the RSA object:
oRsa2 := CreateObject("Chilkat.Rsa")

//  Import the public key into the RSA object:
nSuccess := oRsa2:UsePublicKey(oPubKey)
IF (nSuccess == 0)
    ? oRsa2:LastErrorText
    oPrivKey:destroy()
    oRsa:destroy()
    oCert:destroy()
    oPubKey:destroy()
    oRsa2:destroy()
    RETURN
ENDIF

//  The signature is a hex string, so make sure the EncodingMode is correct:
oRsa2:EncodingMode := "hex"

//  Verify the signature:
nSuccess := oRsa2:VerifyStringENC(cStrData, "sha256", cHexSig)
IF (nSuccess == 0)
    ? oRsa2:LastErrorText
    oPrivKey:destroy()
    oRsa:destroy()
    oCert:destroy()
    oPubKey:destroy()
    oRsa2:destroy()
    RETURN
ENDIF

? "Success."

oPrivKey:destroy()
oRsa:destroy()
oCert:destroy()
oPubKey:destroy()
oRsa2:destroy()