The AuthnLevel argument represents the authentication level supplied to the RpcBindingInqAuthInfo and RpcBindingSetAuthInfo run-time functions.
The levels are listed in order of increasing authentication. Each new level adds to the authentication provided by the previous level. If the RPC run-time library does not support the specified level, it automatically upgrades to the next higher supported level.
The following constants represent valid values for the AuthnLevel argument:
| Constant | Description |
|---|---|
| RPC_C_AUTHN_LEVEL_DEFAULT | Uses the default authentication level for the specified authentication service. |
| RPC_C_AUTHN_LEVEL_NONE | Performs no authentication. |
| RPC_C_AUTHN_LEVEL_CONNECT | Authenticates only when the client establishes a relationship with a server. |
| RPC_C_AUTHN_LEVEL_CALL | Authenticates only at the beginning of each remote procedure call when the server receives the request. Does not apply to remote procedure calls made using the connection-based protocol sequences (those that start with the prefix "ncacn"). If the protocol sequence in a binding handle is a connection-based protocol sequence and you specify this level, this routine instead uses the RPC_C_AUTHN_LEVEL_PKT constant. |
| 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. |
Note RPC_C_AUTHN_LEVEL_CALL, RPC_C_AUTHN_LEVEL_PKT, RPC_C_AUTHN_LEVEL_PKT_INTEGRITY, and RPC_C_AUTHN_LEVEL_PKT_PRIVACY are only supported for clients communicating with a Windows NT server. A Windows 95 server can only accept incoming calls at the RPC_C_AUTHN_LEVEL_CONNECT level.
RpcBindingInqAuthInfo, RpcBindingSetAuthInfo