DataFlex

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). DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Variant vCert
    Handle hoCert
    Handle hoBd
    Integer i
    Handle hoRsa
    String sSha256_base64
    String sRsaSig_base64
    String sTemp1

    Move False To iSuccess

    // 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.

    Get Create (RefClass(cComChilkatCert)) To hoCert
    If (Not(IsComObjectCreated(hoCert))) Begin
        Send CreateComObject of hoCert
    End

    // Set the token/smartcard PIN prior to loading.
    Set ComSmartCardPin Of hoCert To "123456"

    // Specify the certificate by its common name.
    Get ComLoadFromSmartcard Of hoCert "cn=chilkat-rsa-2048" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoCert To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComSubjectCN Of hoCert To sTemp1
    Showln "Signing with the private key for this cert: " sTemp1

    // Create data to be hashed and signed.
    Get Create (RefClass(cComChilkatBinData)) To hoBd
    If (Not(IsComObjectCreated(hoBd))) Begin
        Send CreateComObject of hoBd
    End

    For i From 0 To 100
        Get ComAppendEncoded Of hoBd "000102030405060708090A0B0C0D0E0F" "hex" To iSuccess
    Loop

    Get Create (RefClass(cComChilkatRsa)) To hoRsa
    If (Not(IsComObjectCreated(hoRsa))) Begin
        Send CreateComObject of hoRsa
    End

    // Use the certificate's private key for signing.
    Get pvComObject of hoCert to vCert
    Get ComSetX509Cert Of hoRsa vCert True To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoRsa To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // We'll first compute the hash and then pass the encoded hash to be signed.
    Get ComGetHash Of hoBd "sha256" "base64" To sSha256_base64
    Showln "sha256 hash in base64 format: " sSha256_base64

    // Pass in the base64 hash and return a base64 signature.
    Set ComEncodingMode Of hoRsa To "base64"
    Get ComSignHashENC Of hoRsa sSha256_base64 "sha256" To sRsaSig_base64
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoRsa To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "RSA signature as base64: " sRsaSig_base64


End_Procedure