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.

Visual FoxPro

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

lnSuccess = 0

* 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.

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.
loBd = CreateObject('Chilkat.BinData')

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

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.
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