//----------------------------------------------------------------------
// Write Data Page for DS1963S.
//
// 'portnum' - number 0 to MAX_PORTNUM-1. This number is provided to
// indicate the symbolic port number.
// 'pagenum' - page number to write to
// 'data' - buffer to write into page
// 'resume' - if true, device access is resumed using the RESUME
// ROM command (0xA5). Otherwise, a a MATCH ROM is
// used along with the device's entire address number.
//
// Return: TRUE - Write successfull
// FALSE - error occurred during write.
//
SMALLINT WriteDataPageSHA18(int portnum, SMALLINT pagenum,
uchar* data, SMALLINT resume)
{
uchar buffer[32];
int addr = pagenum << 5, addr_buff;
uchar es = 0;
OWASSERT( EraseScratchpadSHA18(portnum, addr, resume),
OWERROR_ERASE_SCRATCHPAD_FAILED, FALSE );
OWASSERT( WriteScratchpadSHA18(portnum, addr, data, 32, TRUE),
OWERROR_WRITE_SCRATCHPAD_FAILED, FALSE );
OWASSERT( ReadScratchpadSHA18(portnum, &addr_buff, &es, buffer, TRUE),
OWERROR_READ_SCRATCHPAD_FAILED, FALSE );
// verify that what we read is exactly what we wrote
OWASSERT( (addr == addr_buff) && (es == 0x1F)
&& (memcmp(buffer, data, 32)==0),
OWERROR_READ_SCRATCHPAD_FAILED, FALSE );
OWASSERT( CopyScratchpadSHA18(portnum, addr, 32, TRUE),
OWERROR_COPY_SCRATCHPAD_FAILED, FALSE );
return TRUE;
}
//-------------------------------------------------------------------------
// Creates a random challenge using the SHA engine of the given
// coprocessor.
//
// 'copr' - Structure for holding coprocessor information.
// 'pagenum' - pagenumber to use for calculation.
// 'chlg' - 3-byte return buffer for challenge.
// 'offset' - offset into resulting MAC to pull challenge data from.
//
// Return: TRUE - create challenge succeeded.
// FALSE - an error occurred.
//
SMALLINT CreateChallenge(SHACopr* copr, SMALLINT pageNum,
uchar* chlg, SMALLINT offset)
{
uchar scratchpad[32];
int addr = pageNum << 5;
uchar es = 0x1F;
int start = 8;
if(offset>0 && offset<17)
start += offset;
//set the serial number
owSerialNum(copr->portnum, copr->devAN, FALSE);
OWASSERT( EraseScratchpadSHA18(copr->portnum, addr, FALSE),
OWERROR_ERASE_SCRATCHPAD_FAILED, FALSE );
OWASSERT( SHAFunction18(copr->portnum, SHA_COMPUTE_CHALLENGE, addr, TRUE),
OWERROR_SHA_FUNCTION_FAILED, FALSE );
OWASSERT( ReadScratchpadSHA18(copr->portnum, &addr, &es, scratchpad, TRUE),
OWERROR_READ_SCRATCHPAD_FAILED, FALSE );
memcpy(chlg,&scratchpad[start],3);
return TRUE;
}
//-------------------------------------------------------------------------
// Answers a random challenge by performing an authenticated read of the
// user's account information.
//
// 'user' - Structure for holding user token information.
// 'chlg' - 3-byte buffer of challenge data.
//
// Return: the value of the write cycle counter for the account page.
// or -1 if there is an error
//
int AnswerChallenge(SHAUser* user, uchar* chlg)
{
int addr = user->accountPageNumber << 5;
user->writeCycleCounter = -1;
memcpy(&user->accountFile[20], chlg, 3);
//set the serial number
owSerialNum(user->portnum, user->devAN, FALSE);
if(user->devAN[0]==0x18)
{
// for the DS1963S
OWASSERT( EraseScratchpadSHA18(user->portnum, addr, FALSE),
OWERROR_ERASE_SCRATCHPAD_FAILED, -1 );
OWASSERT( WriteScratchpadSHA18(user->portnum, addr,
user->accountFile, 32,
TRUE),
OWERROR_WRITE_SCRATCHPAD_FAILED, -1 );
user->writeCycleCounter =
ReadAuthPageSHA18(user->portnum,
user->accountPageNumber,
user->accountFile,
user->responseMAC, TRUE);
}
else if(user->devAN[0]==0x33||user->devAN[0]==0xB3)
{
// for the DS1961S
OWASSERT( WriteScratchpadSHA33(user->portnum, addr,
&user->accountFile[16],
FALSE),
OWERROR_WRITE_SCRATCHPAD_FAILED, -1 );
user->writeCycleCounter =
ReadAuthPageSHA33(user->portnum,
user->accountPageNumber,
user->accountFile,
user->responseMAC, TRUE);
}
return user->writeCycleCounter;
}