如何确定在用户的本地管理员帐户的上下文中运行的线程
https://support.microsoft.com/zh-cn/kb/118626
概要
Windows 2000 及更高版本,您可以使用CheckTokenMembership() API 而不是在这篇文章中介绍的步骤。有关其他信息,请参阅 Microsoft 平台 SDK 文档。
详细信息
获取当前用户的令牌之后,可以使用访问权限检查功能来检测用户是否为管理员。若要执行此操作,请按照下列步骤操作:
- 通过使用AllocateAndInitializeSid函数创建本地管理员组的安全标识符 (SID)。
- 构建新的安全描述符 (SD) 的自由访问控制列表 (DACL),其中包含访问控制项 (ACE) 的管理员组的 SID。
- 调用与当前用户和新构造的 SD,来检测用户是否为管理员令牌访问权限检查。
示例代码
#include <windows.h>
#include <stdio.h>
#include <lmcons.h>
BOOL IsCurrentUserLocalAdministrator(void);
void main(int argc, char **argv)
{
if (IsCurrentUserLocalAdministrator())
printf("You are an administrator\n");
else
printf("You are not an administrator\n");
}
/*-------------------------------------------------------------------------
-
IsCurrentUserLocalAdministrator ()
This function checks the token of the calling thread to see if the caller
belongs to the Administrators group.
Return Value:
TRUE if the caller is an administrator on the local machine.
Otherwise, FALSE.
--------------------------------------------------------------------------*
/
BOOL IsCurrentUserLocalAdministrator(void)
{
BOOL fReturn = FALSE;
DWORD dwStatus;
DWORD dwAccessMask;
DWORD dwAccessDesired;
DWORD dwACLSize;
DWORD dwStructureSize = sizeof(PRIVILEGE_SET);
PACL pACL = NULL;
PSID psidAdmin = NULL;
HANDLE hToken = NULL;
HANDLE hImpersonationToken = NULL;
PRIVILEGE_SET ps;
GENERIC_MAPPING GenericMapping;
PSECURITY_DESCRIPTOR psdAdmin = NULL;
SID_IDENTIFIER_AUTHORITY SystemSidAuthority = SECURITY_NT_AUTHORITY;
/*
Determine if the current thread is running as a user that is a member
of
the local admins group. To do this, create a security descriptor
that
has a DACL which has an ACE that allows only local aministrators
access.
Then, call AccessCheck with the current thread's token and the
security
descriptor. It will say whether the user could access an object if
it
had that security descriptor. Note: you do not need to actually
create
the object. Just checking access against the security descriptor
alone
will be sufficient.
*/
const DWORD ACCESS_READ = 1;
const DWORD ACCESS_WRITE = 2;
__try
{
/*
AccessCheck() requires an impersonation token. We first get a
primary
token and then create a duplicate impersonation token. The
impersonation token is not actually assigned to the thread, but is
used in the call to AccessCheck. Thus, this function itself never
impersonates, but does use the identity of the thread. If the
thread
was impersonating already, this function uses that impersonation
context.
*/
if (!OpenThreadToken(GetCurrentThread(), TOKEN_DUPLICATE|TOKEN_QUERY,
TRUE, &hToken))
{
if (GetLastError() != ERROR_NO_TOKEN)
__leave;
if (!OpenProcessToken(GetCurrentProcess(),
TOKEN_DUPLICATE|TOKEN_QUERY, &hToken))
__leave;
}
if (!DuplicateToken (hToken, SecurityImpersonation,
&hImpersonationToken))
__leave;
/*
Create the binary representation of the well-known SID that
represents the local administrators group. Then create the
security
descriptor and DACL with an ACE that allows only local admins
access.
After that, perform the access check. This will determine whether
the current user is a local admin.
*/
if (!AllocateAndInitializeSid(&SystemSidAuthority, 2,
SECURITY_BUILTIN_DOMAIN_RID,
DOMAIN_ALIAS_RID_ADMINS,
0, 0, 0, 0, 0, 0, &psidAdmin))
__leave;
psdAdmin = LocalAlloc(LPTR, SECURITY_DESCRIPTOR_MIN_LENGTH);
if (psdAdmin == NULL)
__leave;
if (!InitializeSecurityDescriptor(psdAdmin,
SECURITY_DESCRIPTOR_REVISION))
__leave;
// Compute size needed for the ACL.
dwACLSize = sizeof(ACL) + sizeof(ACCESS_ALLOWED_ACE) +
GetLengthSid(psidAdmin) - sizeof(DWORD);
pACL = (PACL)LocalAlloc(LPTR, dwACLSize);
if (pACL == NULL)
__leave;
if (!InitializeAcl(pACL, dwACLSize, ACL_REVISION2))
__leave;
dwAccessMask= ACCESS_READ | ACCESS_WRITE;
if (!AddAccessAllowedAce(pACL, ACL_REVISION2, dwAccessMask,
psidAdmin))
__leave;
if (!SetSecurityDescriptorDacl(psdAdmin, TRUE, pACL, FALSE))
__leave;
/*
AccessCheck validates a security descriptor somewhat; set the
group
and owner so that enough of the security descriptor is filled out
to
make AccessCheck happy.
*/
SetSecurityDescriptorGroup(psdAdmin, psidAdmin, FALSE);
SetSecurityDescriptorOwner(psdAdmin, psidAdmin, FALSE);
if (!IsValidSecurityDescriptor(psdAdmin))
__leave;
dwAccessDesired = ACCESS_READ;
/*
Initialize GenericMapping structure even though you
do not use generic rights.
*/
GenericMapping.GenericRead = ACCESS_READ;
GenericMapping.GenericWrite = ACCESS_WRITE;
GenericMapping.GenericExecute = 0;
GenericMapping.GenericAll = ACCESS_READ | ACCESS_WRITE;
if (!AccessCheck(psdAdmin, hImpersonationToken, dwAccessDesired,
&GenericMapping, &ps, &dwStructureSize, &dwStatus,
&fReturn))
{
fReturn = FALSE;
__leave;
}
}
__finally
{
// Clean up.
if (pACL) LocalFree(pACL);
if (psdAdmin) LocalFree(psdAdmin);
if (psidAdmin) FreeSid(psidAdmin);
if (hImpersonationToken) CloseHandle (hImpersonationToken);
if (hToken) CloseHandle (hToken);
}
return fReturn;
}
作者:Dozeoo
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