RPC_C_AUTHN_LEVEL_DEFAULT

Tells DCOM to choose the authentication level using its normal security blanket negotiation algorithm. This behavior occurs in Windows 2000 and later versions. In Windows NT 4.0, this value defaults to RPC_C_AUTHN_LEVEL_CONNECT. For more information, see Security Blanket Negotiation.

RPC_C_AUTHN_LEVEL_NONE

Performs no authentication.

RPC_C_AUTHN_LEVEL_CONNECT

Authenticates the credentials of the client only when the client establishes a relationship with the server. Datagram transports always use RPC_AUTHN_LEVEL_PKT instead.

RPC_C_AUTHN_LEVEL_CALL

Authenticates only at the beginning of each remote procedure call when the server receives the request. Datagram transports use RPC_C_AUTHN_LEVEL_PKT instead.

RPC_C_AUTHN_LEVEL_PKT

Authenticates that all data received is from the expected client.

RPC_C_AUTHN_LEVEL_PKT_INTEGRITY

Authenticates and verifies that none of the data transferred between client and server has been modified.

RPC_C_AUTHN_LEVEL_PKT_PRIVACY

Authenticates all previous levels and encrypts the argument value of each remote procedure call.

Windows 95: While Windows 95 can make calls at any level, it can receive calls only at NONE or CONNECT.

For an explanation of the requirement values, see Requirements (COM).

Windows NT/2000/XP: Requires Windows NT 3.1 or later.

Windows 95/98: Requires Windows 95 or later.

Header: Declared in rpcdce.h.

Reference