(PureBasic) Get ECC Private Key in JWK Format (JSON Web Key)

Demonstrates how to get an ECC private key in JWK (JSON Web Key) format.

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

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IncludeFile "CkStringBuilder.pb"
IncludeFile "CkPrivateKey.pb"
IncludeFile "CkJsonObject.pb"

Procedure ChilkatExample()

    ; Note: This example requires Chilkat v9.5.0.66 or later.

    ; Load a PEM file into memory.
    sbPem.i = CkStringBuilder::ckCreate()
    If sbPem.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success.i = CkStringBuilder::ckLoadFile(sbPem,"qa_data/pem/ecc_privKey.pem","utf-8")
    If success <> 1
        Debug "Failed to load PEM file."
        CkStringBuilder::ckDispose(sbPem)
        ProcedureReturn
    EndIf

    ; Load the PEM into a private key object.
    privKey.i = CkPrivateKey::ckCreate()
    If privKey.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkPrivateKey::ckLoadPem(privKey,CkStringBuilder::ckGetAsString(sbPem))
    If success <> 1
        Debug CkPrivateKey::ckLastErrorText(privKey)
        CkStringBuilder::ckDispose(sbPem)
        CkPrivateKey::ckDispose(privKey)
        ProcedureReturn
    EndIf

    ; Get the private key in JWK format:
    jwk.s = CkPrivateKey::ckGetJwk(privKey)

    ; The GetJwk method will return the JWK in the most compact JSON format possible,
    ; as a single line with no extra whitespace.  To get a more human-readable JWK (for this example),
    ; load into a Chilkat JSON object and emit non-compact:

    json.i = CkJsonObject::ckCreate()
    If json.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkJsonObject::ckLoad(json,jwk)
    CkJsonObject::setCkEmitCompact(json, 0)
    Debug "ECC Private Key in JWK format:"
    Debug CkJsonObject::ckEmit(json)

    ; Sample output:
    ; { 
    ;   "kty": "EC",
    ;   "crv": "P-256",
    ;   "x": "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE",
    ;   "y": "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU",
    ;   "d": "EbVzfPnZPxfAyxqEZV05laAoJAl-_6Xt2O4mOB611sM"
    ; }
    ; 

    ; Additional information can be added like this:
    CkJsonObject::ckAppendString(json,"use","enc")
    CkJsonObject::ckAppendString(json,"kid","123ABC")

    ; Now examine the JSON:
    Debug CkJsonObject::ckEmit(json)

    ; { 
    ;   "kty": "EC",
    ;   "crv": "P-256",
    ;   "x": "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE",
    ;   "y": "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU",
    ;   "d": "EbVzfPnZPxfAyxqEZV05laAoJAl-_6Xt2O4mOB611sM",
    ;   "use": "enc",
    ;   "kid": "123ABC"
    ; }


    CkStringBuilder::ckDispose(sbPem)
    CkPrivateKey::ckDispose(privKey)
    CkJsonObject::ckDispose(json)


    ProcedureReturn
EndProcedure