Set the Shared JWE Unprotected Header

See more JSON Web Encryption (JWE) Examples

Demonstrates Jwe.SetUnprotectedHeader, which sets the shared JWE unprotected header from a JsonObject.

IncludeFile "CkStringBuilder.pb"
IncludeFile "CkJwe.pb"
IncludeFile "CkJsonObject.pb"

Procedure ChilkatExample()

    success.i = 0

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

    ;  Protected header: AES key-wrap with AES-256-GCM content encryption.
    header.i = CkJsonObject::ckCreate()
    If header.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkJsonObject::ckUpdateString(header,"alg","A256KW")
    CkJsonObject::ckUpdateString(header,"enc","A256GCM")
    success = CkJwe::ckSetProtectedHeader(jwe,header)
    If success = 0
        Debug CkJwe::ckLastErrorText(jwe)
        CkJwe::ckDispose(jwe)
        CkJsonObject::ckDispose(header)
        ProcedureReturn
    EndIf

    ;  The 256-bit key-wrapping key (base64) for recipient index 0.  In production, obtain the key from a
    ;  secure source rather than hard-coding it.
    base64Key.s = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU="
    success = CkJwe::ckSetWrappingKey(jwe,0,base64Key,"base64")
    If success = 0
        Debug CkJwe::ckLastErrorText(jwe)
        CkJwe::ckDispose(jwe)
        CkJsonObject::ckDispose(header)
        ProcedureReturn
    EndIf

    ;  Set the shared JWE unprotected header.  It is shared by all recipients but, unlike the protected
    ;  header, is not integrity-protected.
    unprotected.i = CkJsonObject::ckCreate()
    If unprotected.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkJsonObject::ckUpdateString(unprotected,"cty","text/plain")
    success = CkJwe::ckSetUnprotectedHeader(jwe,unprotected)
    If success = 0
        Debug CkJwe::ckLastErrorText(jwe)
        CkJwe::ckDispose(jwe)
        CkJsonObject::ckDispose(header)
        CkJsonObject::ckDispose(unprotected)
        ProcedureReturn
    EndIf

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

    CkStringBuilder::ckAppend(sbContent,"This is the secret content.")
    sbJwe.i = CkStringBuilder::ckCreate()
    If sbJwe.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkJwe::ckEncryptSb(jwe,sbContent,"utf-8",sbJwe)
    If success = 0
        Debug CkJwe::ckLastErrorText(jwe)
        CkJwe::ckDispose(jwe)
        CkJsonObject::ckDispose(header)
        CkJsonObject::ckDispose(unprotected)
        CkStringBuilder::ckDispose(sbContent)
        CkStringBuilder::ckDispose(sbJwe)
        ProcedureReturn
    EndIf

    Debug CkStringBuilder::ckGetAsString(sbJwe)


    CkJwe::ckDispose(jwe)
    CkJsonObject::ckDispose(header)
    CkJsonObject::ckDispose(unprotected)
    CkStringBuilder::ckDispose(sbContent)
    CkStringBuilder::ckDispose(sbJwe)


    ProcedureReturn
EndProcedure