Visual FoxPro

RSA Sign an Encoded Hash

See more RSA Examples

Demonstrates signing a hash (e.g., SHA256) provided as an encoded string (e.g., base64 or hex). Visual FoxPro

LOCAL lnSuccess
LOCAL loCert
LOCAL loBd
LOCAL i
LOCAL loRsa
LOCAL lcSha256_base64
LOCAL lcRsaSig_base64

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 the private key for this 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

* We'll first compute the hash and then pass the encoded hash to be signed.
lcSha256_base64 = loBd.GetHash("sha256","base64")
? "sha256 hash in base64 format: " + lcSha256_base64

* Pass in the base64 hash and return a base64 signature.
loRsa.EncodingMode = "base64"
lcRsaSig_base64 = loRsa.SignHashENC(lcSha256_base64,"sha256")
IF (lnSuccess = 0) THEN
    ? loRsa.LastErrorText
    RELEASE loCert
    RELEASE loBd
    RELEASE loRsa
    CANCEL
ENDIF

? "RSA signature as base64: " + lcRsaSig_base64

RELEASE loCert
RELEASE loBd
RELEASE loRsa