PureBasic

Create JWT Using ECC (ES256, ES384, or ES512)

See more JSON Web Token (JWT) Examples

Demonstrates how to create a JWT using an ECC private key. This is for JOSE headers with an "alg" of ES256, ES384, or ES512. When ECC is used, the private key signs (creates) the JWT, and the public key is for verification.

This example also demonstrates how to include time constraints:

• nbf: Not Before Time
• exp: Expiration Time
• iat: Issue At Time

PureBasic

IncludeFile "CkJwt.pb"
IncludeFile "CkPrivateKey.pb"
IncludeFile "CkJsonObject.pb"

Procedure ChilkatExample()

    success.i = 0

    ; Demonstrates how to create a JWT using an ECC private key.

    ; This example requires the Chilkat API to have been previously unlocked.
    ; See Global Unlock Sample for sample code.

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

    ; Load an ECC private key from a PEM file.
    success = CkPrivateKey::ckLoadPemFile(privKey,"qa_data/pem/ecc_privKey.pem")
    If success <> 1
        Debug CkPrivateKey::ckLastErrorText(privKey)
        CkPrivateKey::ckDispose(privKey)
        ProcedureReturn
    EndIf

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

    ; Build the JOSE header
    jose.i = CkJsonObject::ckCreate()
    If jose.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Use ES256.  Pass the string "ES384" or "ES512" to use ECC with SHA-384 or SHA-512.
    success = CkJsonObject::ckAppendString(jose,"alg","ES256")
    success = CkJsonObject::ckAppendString(jose,"typ","JWT")

    ; Now build the JWT claims (also known as the payload)
    claims.i = CkJsonObject::ckCreate()
    If claims.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkJsonObject::ckAppendString(claims,"iss","http://example.org")
    success = CkJsonObject::ckAppendString(claims,"sub","John")
    success = CkJsonObject::ckAppendString(claims,"aud","http://example.com")

    ; Set the timestamp of when the JWT was created to now.
    curDateTime.i = CkJwt::ckGenNumericDate(jwt,0)
    success = CkJsonObject::ckAddIntAt(claims,-1,"iat",curDateTime)

    ; Set the "not process before" timestamp to now.
    success = CkJsonObject::ckAddIntAt(claims,-1,"nbf",curDateTime)

    ; Set the timestamp defining an expiration time (end time) for the token
    ; to be now + 1 hour (3600 seconds)
    success = CkJsonObject::ckAddIntAt(claims,-1,"exp",curDateTime + 3600)

    ; Produce the smallest possible JWT:
    CkJwt::setCkAutoCompact(jwt, 1)

    ; Create the JWT token.  This is where the ECC signature is created.
    token.s = CkJwt::ckCreateJwtPk(jwt,CkJsonObject::ckEmit(jose),CkJsonObject::ckEmit(claims),privKey)

    Debug token

    ; Example output:
    ; eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJodHRwOi8vZXhhbXBsZS5vcmciLCJzdWIiOiJKb2huIiwiYXVkIjoiaHR0cDovL2V4YW1wbGUuY29tIiwiaWF0IjoxNDg1NzA4NzkyLCJuYmYiOjE0ODU3MDg3OTIsImV4cCI6MTQ4NTcxMjM5Mn0.wqsuyJpxJ073ox-lOiLFqG1lQocXe4hGf2XGZJRrO3qn0UusxI_bu3Gzky8gBsH4sA4u9TWZn5M-1wYMMIJk6Q


    CkPrivateKey::ckDispose(privKey)
    CkJwt::ckDispose(jwt)
    CkJsonObject::ckDispose(jose)
    CkJsonObject::ckDispose(claims)


    ProcedureReturn
EndProcedure