NAME

       Tspi_Context_UnregisterKey - unregister a key from the persistent storage device.

SYNOPSIS

       #include <tss/platform.h>
       #include <tss/tcpa_defines.h>
       #include <tss/tcpa_typedef.h>
       #include <tss/tcpa_struct.h>
       #include <tss/tss_typedef.h>
       #include <tss/tss_structs.h>
       #include <tss/tspi.h>

       TSS_RESULT Tspi_Context_UnregisterKey(TSS_HCONTEXT hContext, TSS_FLAG  persistentStorageType,
                                             TSS_UUID     uuidKey,  TSS_HKEY* phKey);

DESCRIPTION

       TSS_Context_UnregisterKey provides the capabilities of the TSS Core Service or TSS Service
       Provider

PARAMETERS

   hContext
       The handle of the context object.

   persistentStorageType
       Flag indicating the persistent storage.

   uuidKey
       The UUID of the key to be removed from the persistent storage.

   phKey
       Recieves the handle of a key object containing the information from the archive.

   pulRespDataLength
       Recieves the length (in bytes) of the prgbRespData parameter.

   prgbRespData
       On successful completion of the command, this parameter points to  the  buffer  containing
       the actual data of the specified capability.  The handle of the object to be destroyed

RETURN CODES

       Tspi_Context_UnregisterKey  returns TSS_SUCCESS on success, otherwise one of the following
       values are returned:

       TSS_E_INVALID_HANDLE - the parameter hContext is an invalid parameter.

       TSS_E_PS_KEY_NOTFOUND - the parameter uuidKey is an invalid UUID.

       TSS_E_INTERNAL_ERROR - An error occurred internal to the TSS.

EXAMPLE

       #include <trousers/tss.h>

       int
       main(void)
       {
            TSS_FLAGS initFlags = ...;
            TSS_HKEY  hKey, hSRK;
            TSS_UUID  keyUUID = {...};

            // Create a TSP handle
            result = Tspi_Context_Create(&hContext);
            if (result != TSS_SUCCESS)
                 Error_Path();

            // Connect to the TCSD
            result = Tspi_Context_Connect(hContext, GLOBALSERVER);
            if (result != TSS_SUCCESS)
                 Error_Path();

            // Create the Key Object
            result = Tspi_Context_CreateObject(hContext,
                      TSS_OBJECT_TYPE_RSAKEY,
                      initFlags, &hKey);
            if (result != TSS_SUCCESS)
                 Error_Path();

            // Load parent Key by UUID
            result = Tspi_Context_LoadKeyByUUID(hContext, TSS_PS_TYPE_SYSTEM,
                      SRK_UUID, &hSRK);
            if (result != TSS_SUCCESS)
                 Error_Path();

            // Do policy/secret handling here

            result = Tspi_Key_CreateKey(hKey, hSRK, 0);
            if (result != TSS_SUCCESS)
                 Error_Path();

            // Register the Key in System PS (on the TCSD's platform)
            result = Tspi_Context_RegisterKey(hContext, hKey, TSS_PS_TYPE_SYSTEM,
                      keyUUID, TSS_PS_TYPE_SYSTEM,
                      SRK_UUID);
            if (result != TSS_SUCCESS)
                 Error_Path();

            /* ...
             *
             * Use the key as needed, exiting the program if necessary, reloading
             * the key using Tspi_Context_LoadKeyByUUID() after each restart. Once
             * the key is no longer useful, unregister it from system PS as part
             * of clean up.
             */

            // Unregister the Key
            result = Tspi_Context_UnregisterKey(hContext, TSS_PS_TYPE_SYSTEM,
                      migratableSignUUID, &hKey);
            if (result != TSS_SUCCESS)
                 Error_Path();

            // exit, discarding hKey
       }

CONFORMING TO

       Tspi_Context_UnregisterKey conforms to the Trusted Computing Group Software  Specification
       version 1.1 Golden

SEE ALSO

       Tspi_Key_CreateKey(3), Tspi_Context_RegisterKey(3).