Xbase++

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. Xbase++

LOCAL nSuccess
LOCAL oCert
LOCAL oSb
LOCAL nCrlfLineEnding
LOCAL i
LOCAL oRsa
LOCAL cStringToSign
LOCAL cSigBase64

nSuccess := 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.

oCert := CreateObject("Chilkat.Cert")

//  Set the token/smartcard PIN prior to loading.
oCert:SmartCardPin := "123456"

//  Specify the certificate by its common name.
nSuccess := oCert:LoadFromSmartcard("cn=chilkat-rsa-2048")
IF (nSuccess == 0)
    ? oCert:LastErrorText
    oCert:destroy()
    RETURN
ENDIF

? "Signing with cert: " + oCert:SubjectCN

//  Create a string to be hashed and signed.
oSb := CreateObject("Chilkat.StringBuilder")
nCrlfLineEnding := 1

FOR i := 0 TO 10
    oSb:AppendLine("This is a test.", nCrlfLineEnding)
NEXT

oRsa := CreateObject("Chilkat.Rsa")

//  Use the certificate's private key for signing.
nSuccess := oRsa:SetX509Cert(oCert, 1)
IF (nSuccess == 0)
    ? oRsa:LastErrorText
    oCert:destroy()
    oSb:destroy()
    oRsa:destroy()
    RETURN
ENDIF

//  Sign the SHA-256 hash of the utf-8 byte representation of the contents of sb
//  Return the signature in base64 format.
oRsa:EncodingMode := "base64"
oRsa:Charset := "utf-8"
cStringToSign := oSb:GetAsString()
cSigBase64 := oRsa:SignStringENC(cStringToSign, "sha256")
IF (oRsa:LastMethodSuccess == 0)
    ? oRsa:LastErrorText
    oCert:destroy()
    oSb:destroy()
    oRsa:destroy()
    RETURN
ENDIF

? "RSA signature as base64: " + cSigBase64

oCert:destroy()
oSb:destroy()
oRsa:destroy()