(Visual FoxPro) RSA Sign using a Private Key on a USB Token or Smartcard

See more Apple Keychain Examples

Create an RSA signature using a private key stored on a USB token or smartcard.

Note: On MacOS and iOS, this example requires Chilkat v10.1.2 or later when the Apple Keychain is used as the underlying means to do the signing.

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

LOCAL loCert
LOCAL lnSuccess
LOCAL loBd
LOCAL i
LOCAL loRsa
LOCAL loBdSig

* Assuming the smartcard/USB token is installed with the correct drivers from the manufacturer,
* this code can work on multiple platforms including Windows, MacOS, Linux, and iOS.

* Chilkat automatically detects and determines the way in which the HSM is used,
* which can be by PKCS11, Apple Keychain, Microsoft CNG / Crypto API, or ScMinidriver.

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

* Set the token/smartcard PIN prior to loading.
loCert.SmartCardPin = "123456"

* Specify the certificate by its common name.
lnSuccess = loCert.LoadFromSmartcard("cn=chilkat-rsa-2048")
IF (lnSuccess = 0) THEN
    ? loCert.LastErrorText
    RELEASE loCert
    CANCEL
ENDIF

? "Signing with cert: " + loCert.SubjectCN

* Create data to be hashed and signed.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.BinData')
loBd = CreateObject('Chilkat.BinData')

FOR i = 0 TO 100
    loBd.AppendEncoded("000102030405060708090A0B0C0D0E0F","hex")
NEXT

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

* Use the certificate's private key for signing.
lnSuccess = loRsa.SetX509Cert(loCert,1)
IF (lnSuccess = 0) THEN
    ? loRsa.LastErrorText
    RELEASE loCert
    RELEASE loBd
    RELEASE loRsa
    CANCEL
ENDIF

* Sign the SHA-256 hash of the contents of bd.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.BinData')
loBdSig = CreateObject('Chilkat.BinData')
lnSuccess = loRsa.SignBd(loBd,"sha256",loBdSig)
IF (lnSuccess = 0) THEN
    ? loRsa.LastErrorText
    RELEASE loCert
    RELEASE loBd
    RELEASE loRsa
    RELEASE loBdSig
    CANCEL
ENDIF

* The RSA signature is equal in length to the size of the RSA key.
? "Output signature size in bits = " + STR(loBdSig.NumBytes * 8)

* We can save the signature for later verification..
loBdSig.WriteFile("rsaSignatures/test1.sig")

* See the example to verify the RSA signature:
* Verfies an RSA Signature

RELEASE loCert
RELEASE loBd
RELEASE loRsa
RELEASE loBdSig