Validate a JWS with a Public Key

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.SetPublicKey, which sets the public key used to validate a signature of a loaded JWS.

The file path is relative to the application's current working directory. An absolute path may also be used. Supply the path appropriate to your own environment.

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoJws
    String sJwsCompact
    Variant vPubKey
    Handle hoPubKey
    Integer v
    String sTemp1

    Move False To iSuccess

    Get Create (RefClass(cComChilkatJws)) To hoJws
    If (Not(IsComObjectCreated(hoJws))) Begin
        Send CreateComObject of hoJws
    End

    //  Load the JWS compact serialization.
    Move "eyJhbGciOiJIUzI1NiJ9.VGhpcyBpcyB0aGUgY29udGVudCB0byBzaWduLg.<signature>" To sJwsCompact
    Get ComLoadJws Of hoJws sJwsCompact To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoJws To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  The file path is relative to the application's current working directory.  An absolute path
    //  may also be used.  Supply the path appropriate to your own environment.
    //  Load the signer's public key and set it for validating signature 0.
    Get Create (RefClass(cComChilkatPublicKey)) To hoPubKey
    If (Not(IsComObjectCreated(hoPubKey))) Begin
        Send CreateComObject of hoPubKey
    End
    Get ComLoadFromFile Of hoPubKey "qa_data/signer_pubkey.pem" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoPubKey To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get pvComObject of hoPubKey to vPubKey
    Get ComSetPublicKey Of hoJws 0 vPubKey To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoJws To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Validate the signature.  Validate returns 1 when valid, 0 when not, or a negative value on error.
    Get ComValidate Of hoJws 0 To v
    If (v < 0) Begin
        Get ComLastErrorText Of hoJws To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    If (v <> 1) Begin
        Showln "The signature is not valid."
        Procedure_Return
    End

    Showln "The signature is valid."


End_Procedure