Visual FoxPro

RSA Sign utf-8 Bytes of String to get Base64 RSA Signature

See more Apple Keychain Examples

Demonstrates how RSA sign the utf-8 byte representation of a string to get the signature in base64 format. Visual FoxPro

LOCAL lnSuccess
LOCAL loCert
LOCAL loSb
LOCAL lnCrlfLineEnding
LOCAL i
LOCAL loRsa
LOCAL lcStringToSign
LOCAL lcSigBase64

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 a string to be hashed and signed.
loSb = CreateObject('Chilkat.StringBuilder')
lnCrlfLineEnding = 1

FOR i = 0 TO 10
    loSb.AppendLine("This is a test.",lnCrlfLineEnding)
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 loSb
    RELEASE loRsa
    CANCEL
ENDIF

* Sign the SHA-256 hash of the utf-8 byte representation of the contents of sb
* Return the signature in base64 format.
loRsa.EncodingMode = "base64"
loRsa.Charset = "utf-8"
lcStringToSign = loSb.GetAsString()
lcSigBase64 = loRsa.SignStringENC(lcStringToSign,"sha256")
IF (loRsa.LastMethodSuccess = 0) THEN
    ? loRsa.LastErrorText
    RELEASE loCert
    RELEASE loSb
    RELEASE loRsa
    CANCEL
ENDIF

? "RSA signature as base64: " + lcSigBase64

RELEASE loCert
RELEASE loSb
RELEASE loRsa