快取存取檢查

當應用程式呼叫 AuthzAccessCheck 函式來執行存取檢查時，可以快取該存取檢查的結果。 當AuthzAccessCheck函式的pAuthzHandle參數不是Null時，函式會執行個別的存取檢查，並要求ACCESS_MASK MAXIMUM_ALLOWED，並快取該檢查的結果。 然後，該檢查結果的控制碼可以當做 AuthzHandle 參數傳遞至 AuthzCachedAccessCheck 函式。 這可加快特定用戶端和安全性 描述元的存取檢查速度。

只能快取存取檢查的靜態部分。 每個存取檢查都必須評估包含PRINCIPAL_SELF SID 的回呼存取控制專案 (ACE) 或 ACE。

當搭配邏輯運算子使用時，屬性變數的格式必須是運算式;否則，系統會將其評估為未知。

範例

下列範例會根據先前存取檢查的快取結果檢查來檢查存取權。 先前的存取檢查是在 使用 Authz API 檢查存取的範例中執行。

BOOL CheckCachedAccess(AUTHZ_CLIENT_CONTEXT_HANDLE hClientContext)
{
    #define MY_MAX 4096


    PSECURITY_DESCRIPTOR                pSecurityDescriptor = NULL;
    ULONG                                cbSecurityDescriptorSize = 0;
    AUTHZ_ACCESS_REQUEST                Request;
    CHAR                                ReplyBuffer[MY_MAX];
    CHAR                                CachedReplyBuffer[MY_MAX];
    PAUTHZ_ACCESS_REPLY                    pReply = (PAUTHZ_ACCESS_REPLY)ReplyBuffer;
    PAUTHZ_ACCESS_REPLY                    pCachedReply = (PAUTHZ_ACCESS_REPLY)CachedReplyBuffer;
    DWORD                                AuthzError =0;
    AUTHZ_ACCESS_CHECK_RESULTS_HANDLE    hCached;

    //Allocate memory for the access request structure.
    RtlZeroMemory(&Request, sizeof(AUTHZ_ACCESS_REQUEST));

    //Set up the access request structure.
    Request.DesiredAccess = READ_CONTROL;
    
    //Allocate memory for the initial access reply structure.
    RtlZeroMemory(ReplyBuffer, MY_MAX);

    //Set up the access reply structure.
    pReply->ResultListLength = 1;
    pReply->Error = (PDWORD) ((PCHAR) pReply + sizeof(AUTHZ_ACCESS_REPLY));
    pReply->GrantedAccessMask = (PACCESS_MASK) (pReply->Error + pReply->ResultListLength);
    pReply->SaclEvaluationResults = NULL;

    //Allocate memory for the cached access reply structure.
    RtlZeroMemory(ReplyBuffer, MY_MAX);

    //Set up the cached access reply structure.
    pCachedReply->ResultListLength = 1;
    pCachedReply->Error = (PDWORD) ((PCHAR) pCachedReply + sizeof(AUTHZ_ACCESS_REPLY));
    pCachedReply->GrantedAccessMask = (PACCESS_MASK) (pCachedReply->Error + pCachedReply->ResultListLength);
    pCachedReply->SaclEvaluationResults = NULL;

    //Create security descriptor.
    if(!ConvertStringSecurityDescriptorToSecurityDescriptor(
        L"O:LAG:BAD:(A;;RC;;;BA)",
        SDDL_REVISION_1,
        &pSecurityDescriptor,
        NULL))
    {
        printf_s("ConvertStringSecurityDescriptorToSecurityDescriptor failed with %d\n", GetLastError()); 
        return FALSE;
    }

    //Call AuthzAccessCheck and cache results.
    if(!AuthzAccessCheck(
        0,
        hClientContext,
        &Request,
        NULL,
        pSecurityDescriptor,
        NULL,
        0,
        pReply,
        &hCached))
    {
        printf_s("AuthzAccessCheck failed with %d\n", GetLastError());
        
    LocalFree(pSecurityDescriptor);
        
        return FALSE;
    }

    //Call AuthzCachedAccessCheck with the cached result from the previous call.
    if(!AuthzCachedAccessCheck(
        0,
        hCached,
        &Request,
        NULL,
        pCachedReply))
    {
        printf_s("AuthzCachedAccessCheck failed with %d\n", GetLastError());
        
        LocalFree(pSecurityDescriptor);
    AuthzFreeHandle(hCached);
    
        return FALSE;
    }

    //Print results.
    if(*pCachedReply->GrantedAccessMask & READ_CONTROL)
    {
        printf_s("Access granted.\n");
    }
    else
    {
        printf_s("Access denied.\n");
    }


  LocalFree(pSecurityDescriptor);
  AuthzFreeHandle(hCached);
    return TRUE;

}

相關主題

將 SID 新增至用戶端內容

使用 Authz API 檢查存取

初始化用戶端內容

查詢用戶端內容