OFFLOAD_IPSEC_ADD_SA structure (ntddndis.h)

Article
09/01/2022

The OFFLOAD_IPSEC_ADD_SA structure contains information for each security association (SA) that a miniport driver adds to a NIC.

Syntax

typedef struct _OFFLOAD_IPSEC_ADD_SA {
  IPAddr                       SrcAddr;
  IPMask                       SrcMask;
  IPAddr                       DestAddr;
  IPMask                       DestMask;
  ULONG                        Protocol;
  USHORT                       SrcPort;
  USHORT                       DestPort;
  IPAddr                       SrcTunnelAddr;
  IPAddr                       DestTunnelAddr;
  USHORT                       Flags;
  SHORT                        NumSAs;
  OFFLOAD_SECURITY_ASSOCIATION SecAssoc[OFFLOAD_MAX_SAS];
  HANDLE                       OffloadHandle;
  ULONG                        KeyLen;
  UCHAR                        KeyMat[1];
} OFFLOAD_IPSEC_ADD_SA, *POFFLOAD_IPSEC_ADD_SA;

Members

SrcAddr

The IP address of the source host (the host sending the packets).

SrcMask

The subnet mask for the source IP address.

DestAddr

The IP address of the destination host (the host receiving the packets).

DestMask

The subnet mask for the destination IP address.

Protocol

The IP protocol. You can specify any combination of IP protocol types (such as TCP, UDP, or ICMP). The encoding of Protocol is identical to that of the Protocol field in an IP header. If Protocol is set to zero, the SA applies to any IP protocol.

SrcPort

A source TCP or UDP port. If SrcPort is set to zero, the SA applies to any source TCP/UDP port.

DestPort

A destination TCP or UDP port. If DestPort is set to zero, the SA applies to any source TCP/UDP port.

SrcTunnelAddr

The IP address for the source endpoint, such as a connector, of a tunnel. The miniport driver uses
SrcTunnelAddr as the source address for the tunnel IP header of packets that are sent on the SA. SrcTunnelAddr is specified only for an SA that applies to the tunnel portion of a packet. SrcTunnelAddr is set to zero for an SA that applies to the transport portion of a packet.

DestTunnelAddr

The IP address for the destination endpoint, such as a connector, of a tunnel. The miniport driver uses DestTunnelAddr as the destination address for the tunnel IP header of packets sent on the SA. DestTunnelAddr is specified only for an SA that applies to the tunnel portion of a packet. DestTunnelAddr is set to zero for an SA that applies to the transport portion of a packet.

Flags

A bitmask that indicates whether the SA that is being added is an inbound or outbound SA as follows:

OFFLOAD_INBOUND_SA

Specifies an inbound SA.

OFFLOAD_OUTBOUND_SA

Specifies an outbound SA.

NumSAs

The number of elements in the SecAssoc array. Each element in the array is an OFFLOAD_SECURITY_ASSOCIATION structure.

SecAssoc[OFFLOAD_MAX_SAS]

A variable-length array that contains the information about the Internet Protocol security (IPsec) operations (AH or ESP) for the SA. The information for each IPsec operations is formatted as an OFFLOAD_SECURITY_ASSOCIATION structure.

The TCP/IP transport specifies one or two OFFLOAD_SECURITY_ASSOCIATION structures in the buffer at SecAssoc . Each OFFLOAD_SECURITY_ASSOCIATION structure indicates the type of operation--authentication or encryption/decryption--for which the SA specified in the structure is to be used. The order of the OFFLOAD_SECURITY_ASSOCIATION structures in the array indicates the order in which the miniport driver should perform the operations for each SA. Only one combination of operations is supported: encryption/decryption (ESP) followed by authentication (AH).

OffloadHandle

The handle to the newly created SA. The miniport driver supplies this handle before completing the
OID_TCP_TASK_IPSEC_ADD_SA request. The TCP/IP transport must specify this handle in the NDIS_IPSEC_PACKET_INFO structure before passing a send packet to the miniport driver. The TCP/IP transport must also specify this handle when deleting the SA with an OID_TCP_TASK_IPSEC_DELETE_SA request.

KeyLen

The length, in bytes, of the buffer at KeyMat .

KeyMat[1]

A variable-length array that contains keys for the SAs specified at SecAssoc . If both a confidentiality (encryption/decryption) algorithm and an integrity (authentication) algorithm are specified by the ConfAlgo and IntegrityAlgo members of an OFFLOAD_SECURITY_ASSOCIATION structure, the buffer at KeyMat contains key information for the confirmation algorithm first, followed immediately by key information for the integrity algorithm.

The length of each key in the buffer at KeyMat is specified by algoKeylen in the OFFLOAD_ALGO_INFO structure that specifies the confidentiality or integrity algorithm. (An OFFLOAD_ALGO_INFO structure is a member of an OFFLOAD_SECURITY_ASSOCIATION structure.)

Remarks

The OFFLOAD_IPSEC_ADD_SA structure is used in the OID_TCP_TASK_IPSEC_ADD_SA OID.

Requirements

Requirement	Value
Header	ntddndis.h (include Ndis.h)