DataFlex

Compute JWK Thumbprint for RSA and EC Public Keys

See more ECC Examples

Demonstrates how to compute a JSON Web Key thumbprint for a public key (RSA or ECC).

Note: This example requires Chilkat v9.5.0.66 or greater.

DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoPubKey
    Handle hoSb
    String sTemp1

    Move False To iSuccess

    Get Create (RefClass(cComChilkatPublicKey)) To hoPubKey
    If (Not(IsComObjectCreated(hoPubKey))) Begin
        Send CreateComObject of hoPubKey
    End

    // A public key can be loaded from any format (binary DER, PEM, etc.)
    // This example will load the public keys from JWK format, 
    // and will then compute the JWK thumbprint.

    // First do it for an RSA public key...

    Get Create (RefClass(cComChilkatStringBuilder)) To hoSb
    If (Not(IsComObjectCreated(hoSb))) Begin
        Send CreateComObject of hoSb
    End
    Get ComAppend Of hoSb "{" To iSuccess
    Get ComAppend Of hoSb '"kty": "RSA",' To iSuccess
    Get ComAppend Of hoSb '"n": "0vx7agoebGcQSuuPiLJXZptN9nndrQmbXEps2aiAFbWhM78LhWx4cbbfAAt' To iSuccess
    Get ComAppend Of hoSb "VT86zwu1RK7aPFFxuhDR1L6tSoc_BJECPebWKRXjBZCiFV4n3oknjhMstn6" To iSuccess
    Get ComAppend Of hoSb "4tZ_2W-5JsGY4Hc5n9yBXArwl93lqt7_RN5w6Cf0h4QyQ5v-65YGjQR0_FD" To iSuccess
    Get ComAppend Of hoSb "W2QvzqY368QQMicAtaSqzs8KJZgnYb9c7d0zgdAZHzu6qMQvRL5hajrn1n9" To iSuccess
    Get ComAppend Of hoSb "1CbOpbISD08qNLyrdkt-bFTWhAI4vMQFh6WeZu0fM4lFd2NcRwr3XPksINH" To iSuccess
    Get ComAppend Of hoSb 'aQ-G_xBniIqbw0Ls1jF44-csFCur-kEgU8awapJzKnqDKgw",' To iSuccess
    Get ComAppend Of hoSb '"e": "AQAB",' To iSuccess
    Get ComAppend Of hoSb '"alg": "RS256",' To iSuccess
    Get ComAppend Of hoSb '"kid": "2011-04-29"' To iSuccess
    Get ComAppend Of hoSb "}" To iSuccess

    // The JWK format is automatically detected..
    Get ComGetAsString Of hoSb To sTemp1
    Get ComLoadFromString Of hoPubKey sTemp1 To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoPubKey To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Get the JWK thumbprint (using SHA256)
    Get ComGetJwkThumbprint Of hoPubKey "SHA256" To sTemp1
    Showln "JWK thumbprint: " sTemp1

    // Output:
    // JWK thumbprint: NzbLsXh8uDCcd-6MNwXF4W_7noWXFZAfHkxZsRGC9Xs

    // --------------------------------------------------------------
    // Now let's do an EC public key:
    Send ComClear To hoSb
    Get ComAppend Of hoSb "{ " To iSuccess
    Get ComAppend Of hoSb '  "kty": "EC",' To iSuccess
    Get ComAppend Of hoSb '  "crv": "P-256",' To iSuccess
    Get ComAppend Of hoSb '  "x": "tDeeYABgKEAbWicYPCEEI8sP4SRIhHKcHDW7VqrB4LA",' To iSuccess
    Get ComAppend Of hoSb '  "y": "J08HOoIZ0rX2Me3bNFZUltfxIk1Hrc8FsLu8VaSxsMI"' To iSuccess
    Get ComAppend Of hoSb "}" To iSuccess

    Get ComGetAsString Of hoSb To sTemp1
    Get ComLoadFromString Of hoPubKey sTemp1 To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoPubKey To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Get the JWK thumbprint (using SHA256)
    Get ComGetJwkThumbprint Of hoPubKey "SHA256" To sTemp1
    Showln "JWK thumbprint: " sTemp1

    // Output:
    // JWK thumbprint: 8fm8079s3nu4FLV_7dVJoJ69A8XCXn7Za2mtaWCnxR4


End_Procedure