DuplicateTokenEx info  Overview  Group

The DuplicateTokenEx function creates a new access token that duplicates an existing token. This function can create either a primary token or an impersonation token.

BOOL DuplicateTokenEx(

HANDLE hExistingToken,	// handle to token to duplicate
DWORD dwDesiredAccess,	// access rights of new token
LPSECURITY_ATTRIBUTES lpTokenAttributes,	// security attributes of the new token
SECURITY_IMPERSONATION_LEVEL ImpersonationLevel,	// impersonation level of new token
TOKEN_TYPE TokenType,	// primary or impersonation token
PHANDLE phNewToken	// handle to duplicated token
);

Parameters

hExistingToken

Identifies an access token opened with TOKEN_DUPLICATE access.

dwDesiredAccess

Specifies the requested access rights for the new token. The DuplicateTokenEx function compares the requested access rights with the existing token’s discretionary access-control list (ACL) to determine which rights are granted or denied. To request the same access rights as the existing token, specify zero. To request all access rights that are valid for the caller, specify MAXIMUM_ALLOWED. Otherwise, specify a combination of the following access rights.

Value	Meaning
TOKEN_ADJUST_DEFAULT	Required to change the default ACL, primary group, or owner of an access token.
TOKEN_ADJUST_GROUPS	Required to change the groups specified in an access token.
TOKEN_ADJUST_PRIVILEGES	Required to change the privileges specified in an access token.
TOKEN_ALL_ACCESS	Combines the STANDARD_RIGHTS_REQUIRED standard access rights and all individual access rights for tokens.
TOKEN_ASSIGN_PRIMARY	Required to attach a primary token to a process in addition to the SE_CREATE_TOKEN_NAME privilege.
TOKEN_DUPLICATE	Required to duplicate an access token.
TOKEN_EXECUTE	Combines the STANDARD_RIGHTS_EXECUTE standard access rights and the TOKEN_IMPERSONATE access right.
TOKEN_IMPERSONATE	Required to attach an impersonation access token to a process.
TOKEN_QUERY	Required to query the contents of an access token.
TOKEN_QUERY_SOURCE	Required to query the source of an access token.
TOKEN_READ	Combines the STANDARD_RIGHTS_READ standard access rights and the TOKEN_QUERY access right.
TOKEN_WRITE	Combines the STANDARD_RIGHTS_WRITE standard access rights and the TOKEN_ADJUST_PRIVILEGES, TOKEN_ADJUST_GROUPS, and TOKEN_ADJUST_DEFAULT access rights.

lpTokenAttributes

Pointer to a SECURITY_ATTRIBUTES structure that specifies a security descriptor for the new token and determines whether child processes can inherit the token. If lpTokenAttributes is NULL, the token gets a default security descriptor and the handle cannot be inherited.

ImpersonationLevel

Specifies a value from the SECURITY_IMPERSONATION_LEVEL enumeration that indicates the impersonation level of the new token.

TokenType

Specifies one of the following values from the TOKEN_TYPE enumeration.

Value	Meaning
TokenPrimary	The new token is a primary token that you can use in the CreateProcessAsUser function.
TokenImpersonation	The new token is an impersonation token.

phNewToken

Pointer to a HANDLE variable that receives the new token.

Return Values

If the function succeeds, the return value is a nonzero value.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

The DuplicateTokenEx function allows you to create a primary token that you can use in the CreateProcessAsUser function. This allows a server application that is impersonating a client to create a process that has the security context of the client. Note that the DuplicateToken function can create only impersonation tokens, which are not valid for CreateProcessAsUser.

The following is a typical scenario for using DuplicateTokenEx to create a primary token. A server application creates a thread that calls one of the impersonation functions, such as ImpersonateNamedPipeClient, to impersonate a client. The impersonating thread then calls the OpenThreadToken function to get its own token, which is an impersonation token that has the security context of the client. The thread specifies this impersonation token in a call to DuplicateTokenEx, specifying the TokenPrimary flag. DuplicateTokenEx creates a primary token that has the security context of the client.

When you have finished using the new token, call the CloseHandle function to close the token handle.

See Also

CloseHandle, CreateProcessAsUser, DdeImpersonateClient, DuplicateToken, ImpersonateNamedPipeClient, OpenThreadToken, RevertToSelf, RpcImpersonateClient, SECURITY_ATTRIBUTES, SECURITY_IMPERSONATION_LEVEL