Production Specification

07/03/02

B roa dcom Co rpo rat ion

Document

5802-DS03-405-R

For key setup operations, the same MCR structure is used as for IPsec crypto/authentication operations. The only difference

is that chip processing of any number of key setups is initiated by writing the address of a master command structure to a

different on-chip master command address register (Master Command Register 2). Both operations still share DMA Control

Register, Status Register, and Error Address Register.

All structures used for communication between the CPU and the chip are defined by their .h pseudo-code C language

representation.

For IPsec crypto/authentication processing, the only alignment restriction placed upon all command and descriptor (not

packet data) memory structures is that they must start on 32-bit (4-byte) boundaries. Beyond that, aligning structures to their

natural boundaries may increase performance in certain systems.

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/* LITTLE ENDIAN command structures for uBSec Chip */

typedef unsigned char u8; /* 8-bit data type */

typedef unsigned short u16; /* 16-bit data type */

/* Data Buffer chain entry */

typedef struct DataBufChain_struct {

unsigned char *dataAddr;

struct DataBufChain_struct *next;

u16 dataLength;

u16 reserved;

} DataBufChain;

/* Context buffer */

typedef struct PktCtxBuf_struct {

/* Keys for 3DES -- three keys of 8 bytes each (56 bits plus parity) */

uint cryptokeys[6];

/*

* Pre-computed HMAC inner & outer state

* (2x16B for MD5, 2x20B for SHA1).

*/

uint HMACInnerState[5];//HMACInnerState[0-3] for MD5, HMACInnerState[0-4] for SHA1

uint HMACOuterState[5];//HMACOuterState[0-3] for MD5, HMACOuterState[0-4] for SHA1

/*

* Crypto IV (copied from payload if explicit, byte swapped if needed)

*/

uint computedIV[2];

/*

* Processing control flags

*/

unsigned int reserved:12; /* Reserved */

unsigned int auth:2; /* MD5, SHA1, None */

unsigned int inbound:1; /* Inbound packet */

unsigned int crypto:1; /* 3DES-CBC or None */

/* Offset to skip authenticated but non-encrypted

header words. Goes to start of IV data. In units of 32-bit words */

u16 cryptoOffset;