IPSEC_OFFLOAD_V2_SECURITY_ASSOCIATION structure (ndis.h)

Article
04/01/2021

[The IPsec Task Offload feature is deprecated and should not be used.]

The IPSEC_OFFLOAD_V2_SECURITY_ASSOCIATION structure specifies a single security association (SA).

Syntax

typedef struct _IPSEC_OFFLOAD_V2_SECURITY_ASSOCIATION {
  ULONG                           Flags;
  IPSEC_OFFLOAD_V2_OPERATION      Operation;
  IPSEC_OFFLOAD_V2_SPI_TYPE       Spi;
  IPSEC_OFFLOAD_V2_ALGORITHM_INFO AuthenticationAlgorithm;
  IPSEC_OFFLOAD_V2_ALGORITHM_INFO EncryptionAlgorithm;
  ULONG                           SequenceNumberHighOrder;
} IPSEC_OFFLOAD_V2_SECURITY_ASSOCIATION, *PIPSEC_OFFLOAD_V2_SECURITY_ASSOCIATION;

Members

Flags

A set of flags that can be combined with a bitwise OR operation. Otherwise, set this member to zero. The following values are valid:

IPSEC_OFFLOAD_V2_ESN_SA

Specifies ESN SA.

Operation

The IPsec operation for which the SA is to be used. The IPSEC_OFFLOAD_V2_OPERATION enumeration defines the supported operations.

Spi

A 32 bit security parameters index (SPI) for the SA.

AuthenticationAlgorithm

The integrity (authentication) algorithm for the SA, formatted as an IPSEC_OFFLOAD_V2_ALGORITHM_INFO structure.

EncryptionAlgorithm

The confidentiality (encryption/decryption) algorithm for the SA, formatted as an IPSEC_OFFLOAD_V2_ALGORITHM_INFO structure.

Note For AES-GCM, the EncryptionAlgorithm member contains the key information. The AuthenticationAlgorithm member of IPSEC_OFFLOAD_V2_SECURITY_ASSOCIATION, and the key length and offset in IPSEC_OFFLOAD_V2_ALGORITHM_INFO, should not be used.

SequenceNumberHighOrder

The sequence number high-order extension. This sequence number high-order extension is defined in RFC 4304. This member represents the high-order portion of the sequence number that is not included in the IPsec header.

Remarks

The IPSEC_OFFLOAD_V2_SECURITY_ASSOCIATION structure is an element in the SecAssoc variable-length array in the IPSEC_OFFLOAD_V2_ADD_SA structure. The number of SAs in the IPSEC_OFFLOAD_V2_SECURITY_ASSOCIATION structure is specified in the NumExtHdrs member of IPSEC_OFFLOAD_V2_ADD_SA.

A SecAssoc element that is specified for use in processing authentication headers (AH) will have an operation type (the Operation member) of IPsecOffloadV2Ah and will have the authentication algorithm in the AuthenticationAlgorithm member. The SA will not have an encryption algorithm in the EncryptionAlgorithm member, so EncryptionAlgorithm will contain zeros.

A SecAssoc element that is specified for use in processing encapsulating security payloads (ESPs) will have an operation type (the Operation member) of IPsecOffloadV2Esp and can have an authentication algorithm, an encryption algorithm, or both. Note that for combined mode algorithms, only the EncryptionAlgorithm member will be specified.

Requirements

Requirement	Value
Minimum supported client	Supported in NDIS 6.1 and later.
Header	ndis.h (include Ndis.h)