TweetFollow Us on Twitter

Copy Protection and Serial Numbers

Volume Number: 13 (1997)
Issue Number: 10
Column Tag: develop

Copy Protection and Serial Numbers

by Brian Bechtel, Apple Computer, Inc.

Copy protection is hard, and it is difficult to find a scheme which is not easily broken. The Mac OS was not designed with copy protection in mind, and there is no unique serial number available on Mac OS based computers. There are some techniques which can be used to help differentiate between two Mac OS computers, and these techniques are described in this article.

DTS does not support copy protection because of the significant compatibility liabilities it involves. This article is a summary of some specific techniques which we have used or recommended in the past. DTS does not maintain expertise in copy protection techniques. Serious copy protection is much more complicated than this article describes.

Uniquely Identifying a Mac OS Computer

In general, the only consistent serial number on a Mac OS based computer computer is on the bar code label which is attached to the outside of the case. There is no internal serial number on the logic board of any current Mac OS based computer computer. There is no internal serial number associated with the operating system. The only Macintosh with a real built-in serial number was the Macintosh XL. This machine had a serial number only because the Lisa (upon which it was based) had a serial number as part of the Lisa design.

There are some hardware devices, found on a limited range of Mac OS computers, which contain some unique identifier which could be used as a serial number. Examples are an Ethernet card installed or built-in Ethernet. (This is because Ethernet devices have an unique ID defined for each device.) Some (but not all) hard drives have a serial number which can be read using the SCSI Manager or ATA Manager. Other devices such as Token Ring cards or FireWire may also provide an unique identifier which may be used as a serial number. None of these hardware devices can be found across the entire Macintosh product line.

Semi-Unique Characteristics

There are some "semi-unique" characteristics which you can use to help you determine if you are running software on the same machine which you were running on before. These are listed roughly in the order I'd recommend considering them.

File ID References

You can create and store the file ID reference for the application file. Create a file ID reference using PBCreateFileIDRef() and store it in an appropriate place. (An example of an appropriate place would be the preferences file. An inappropriate place would be the application resource fork, since this would prevent your application from running from locked media or a network server.) Compare the file ID reference to the file ID reference of the running application (the file ID reference will be in the ioFileID field returned by PBGetCatInfo). If it isn't the same, you are running on a different volume. File ID references are unique within a particular volume; they don't get reused. It's unlikely that two machines will give you the same file ID reference for the same file.

 // AddFileID creates a file ID reference for the 
 // file specified by the FSSpec. It returns the
 // created file ID reference so that you can store
 // this reference for future use.
 //
 OSErr AddFileID(FSSpec *file, long *fileID)
 {
 OSErr err;
 HParmBlkPtr h;
 
 h = (HParmBlkPtr)NewPtrClear(sizeof(HParamBlockRec));
 
 h->fidParam.ioCompletion = nil;
 h->fidParam.ioNamePtr = file->name;
 h->fidParam.ioVRefNum = file->vRefNum;
 h->fidParam.ioSrcDirID = file->parID;

 err = PBCreateFileIDRefSync(h);
 *fileID = h->fidParam.ioFileID;
 DisposePtr((void *)h);
 return(err);
 }

 // GetFileID returns the File ID reference for a file
 // where the File ID reference has previously been
 // created (by calling PBCreateFileIDRef)
 //
 OSErr GetFileID(FSSpec *file, long *fileID)
 {
 OSErr err;
 CInfoPBPtr cInfo;
 
 cInfo = (CInfoPBPtr)NewPtrClear(sizeof(CInfoPBRec));
 
 cInfo->hFileInfo.ioCompletion = nil;
 cInfo->hFileInfo.ioNamePtr = file->name;
 cInfo->hFileInfo.ioVRefNum = file->vRefNum;
 cInfo->hFileInfo.ioFDirIndex = 0;
 cInfo->hFileInfo.ioDirID = file->parID;

 err = PBGetCatInfoSync(cInfo);
 *fileID = cInfo->hFileInfo.ioDirID;
 DisposePtr((void *)cInfo);
 return(err);
 }

Ethernet Address

For those Macs which have an Ethernet card installed or built-in Ethernet, you can use the EGetInfo() call with a csCode of ENetGetInfo to get the currently assigned Ethernet address. See Inside Macintosh:Networking, page 11-26 and 11-36 for more information. Apple publishes sample code demonstrating how to obtain the Ethernet address under Open Transport.

The complication for this technique is that the default Ethernet address may be overridden by a resource of type 'eadr' in the System file. This is documented in Inside Macintosh:Networking on page 11-26. Because it is easily possible to override the hardware address, and because Ethernet is not guaranteed to exist on any particular model, this is not a good scheme.

Similar techniques can be used for a Mac OS computer with Token Ring cards or other cards, but a discussion of these cards is outside the scope of this document.

Hard Disk Serial Number

Some hard disks have serial numbers. Many ATA drives have such a serial number, but most SCSI hard disks do not. Apple publishes ATA demo sample code which shows how to get the serial number of an ATA drive. Only some Macintosh models have ATA drives, so this is not a good general purpose scheme.

SCSI Defect List

Some developers use the defect list from a SCSI drive. This won't work for a non-SCSI machine, but might be a good approach for a SCSI based Mac. See the SCSI-2 specification and Inside Macintosh:Devices for details of using the SCSI Manager. Source code demonstrating use of the SCSI Manager in a general case is on the tool chest developer CD. Only some Macintosh models have SCSI drives, so this is not a good general purpose scheme.

Directory ID of the System Folder

Compare the dirID of the System Folder. Use FindFolder() to get the dirID of the System Folder, and compare it to a previously stored parID. This isn't quite as unique as the file ID, since the system folder as preinstalled will tend to have the same directory ID from one machine to another. If the user creates a new System Folder (e.g. by doing a clean install of System Software, which appears to be a frequent activity when upgrading) then you will have different directory IDs. This is not a good scheme.

 // GetVolumeDirID returns the dirID of the System Folder
 //
 OSErr GetVolumeDirID(long *dirID)
 {
 OSErr err;
 short notUsed;

 err=FindFolder(kOnSystemDisk, kSystemFolderType, no,
 notUsed,dirID);
 return(err);
 }

Volume Creation Date

Compare the creation date of the volume. You can get this information from PBHGetVInfo(). This isn't quite as unique as the file ID, since the volume creation date will be set at the factory when system software is placed on the volume and will only be reset when a volume is reinitialized. Because this value tends to remain the same for a given set of machines, this is not a good scheme.

 long GetVolCreationDate(short vRefNum ) 
 { 
 OSErr err = noErr;
 HParamBlockRec pb;
 Str255 vName;

 vName [ 0 ] = '\0';
 pb.volumeParam.ioCompletion = nil;
 pb.volumeParam.ioNamePtr = vName;
 pb.volumeParam.ioVRefNum = vRefNum;
 pb.volumeParam.ioVolIndex = 0;
 err = PBHGetVInfoSync ( &pb );
 
 return ( pb.volumeParam.ioVCrDat);
 }

Network Registration

Rather than identifying an unique Macintosh, you may decide that you want to prevent multiple copies of the same application running on a network. The method some developers use is to register a fictitious device on the network using NBP (Name Binding Protocol) with the name being single serial number of the license. Other attempts to register the same device and serial number give an error that the program acts on to deny the use of the program. Chapter 3 of Inside Macintosh: Networking is a useful reference for NBP.

 /* 
 * Registers a entity with the specified object and type on the
 * specified socket. The pointer to the NamesTableEntry is
 * returned in ntePtr if the function returns noErr.
 * 
 */
 OSErr MyRegisterName(ConstStr32Param entityObject, 
 ConstStr32Param entityType,
 short socket, 
 NamesTableEntry **ntePtr)
 {
 MPPParamBlock mppPB;
 OSErr result;
 Str32 entityZone = "\p*";
 
 /* Allocate non-relocatable memory in the system heap for 
 * the names table entity 
 */
 *ntePtr = (NamesTableEntry *) 
 NewPtrSys((Size)sizeof(NamesTableEntry));

 if ( ntePtr == NULL )
 {
 result = MemError(); /* Return memory error */
 }
 else
 {
 /* Build the names table entity */
 NBPSetNTE((Ptr) *ntePtr, 
 (Ptr) entityObject, 
 (Ptr) entityType, 
 (Ptr) entityZone, 
 socket);
 
 /* ioRefNum and csCode are filled in by 
 * PRegisterName's glue */
 mppPB.NBPinterval = 0x0f; /* Reasonable values for the */
 mppPB.NBPcount = 0x03; /* interval and retry count */
 mppPB.NBPentityPtr = (Ptr) *ntePtr;
 mppPB.NBPverifyFlag = (char) true; /* unique name */
 
 result = PRegisterName(&mppPB, false);

 if ( result != noErr )
 DisposePtr((Ptr) *ntePtr);
 }

 return ( result );
 }

Note: DTS advises against applications searching the entire intranet for a matching entity. Such a search is time consuming. On a large network with many zones, you can spend substantial amounts of time doing this search. This would be not be considered reasonable in startup code. Instead, we advise that you search the local zone. If necessary, implement an asynchronous background search into the other zones.

Thing You Shouldn't Do

We discourage you from trying to use special tracks on formatted floppies, or special floppies. Apple does not document the floppy drive sufficiently for DTS to support such an action. Also, DiskCopy and other disk copying programs work very well at copying floppies, thus defeating such schemes. (DiskCopy was written inside Apple with access to the source of the floppy driver; we do not publish these details externally.) You should not rely on specific bizarre sectors of the hard disk (Apple relies on multiple vendors for its components. You cannot make undocumented assumptions about a particular machine or class of machines.)

Note: At some point in the future, Apple will create machines which do not support 800K GCR-formatted floppies. You should not depend upon specific hardware features such as 800K GCR formatting for copy protection purposes.

Conclusion

Copy protection is difficult to implement, and it is difficult to find a scheme which is not easily broken. The Mac OS was not designed with copy protection in mind, and there is no unique serial number available across the entire set of Mac OS based computers. There are some techniques which can be used to help differentiate between Mac OS computers, and these techniques are described in this article.

There are many more sophisticated schemes for copy protection. If you are serious about copy protection, you should probably be contacting one of the many companies which specialize in such solutions, rather than writing a solution yourself. Both hardware solutions (such as ADB dongles) and software solutions (such as licensing software) are widely available from third parties. DTS does not support copy protection because of the significant compatibility liabilities it involves. DTS does not maintain expertise in copy protection techniques.

Further References

  1. Inside Macintosh:Devices.
  2. ATA Device Software Guide.
  3. Inside Macintosh:Networking, chapter 3, Name Binding Protocol SCSI-2 specification.

Acknowledgments

Thanks to Quinn, Jim Luther, Vinnie Moscaritolo, and Pete Gontier.


Brian Bechtel works in Developer Technical Support at Apple Computer, where he deals with PC Cards, PowerBooks, and device drivers. In his non-work life (yes, there is such a thing) he enjoys time with his family (Mary, Meg and Tacy), is passionate about the San Jose Sharks hockey team, and plays lousy acoustic guitar.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

RapidWeaver 6.0.5 - Create template-base...
RapidWeaver is a next-generation Web design application to help you easily create professional-looking Web sites in minutes. No knowledge of complex code is required, RapidWeaver will take care of... Read more
Alfred 2.6 - Quick launcher for apps and...
Alfred is an award-winning productivity application for OS X. Alfred saves you time when you search for files online or on your Mac. Be more productive with hotkeys, keywords, and file actions at... Read more
1Password 5.1 - Powerful password manage...
1Password is a password manager that uniquely brings you both security and convenience. It is the only program that provides anti-phishing protection and goes beyond password management by adding Web... Read more
GarageSale 6.9.2 - Create outstanding eB...
GarageSale is a slick, full-featured client application for the eBay online auction system. Create and manage your auctions with ease. With GarageSale, you can create, edit, track, and manage... Read more
calibre 2.17 - Complete e-library manage...
Calibre is a complete e-book library manager. Organize your collection, convert your books to multiple formats, and sync with all of your devices. Let Calibre be your multi-tasking digital librarian... Read more
OmniGraffle Pro 6.1.2 - Create diagrams,...
OmniGraffle Pro helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use... Read more
OmniGraffle 6.1.2 - Create diagrams, flo...
OmniGraffle helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use Graffle to... Read more
RoboForm 2.0.2 - Password manager; syncs...
RoboForm is a password manager that offers one-click login, mobile syncing, easy form filling, and reliable security. Password Manager. RoboForm remembers your passwords so you don't have to! Just... Read more
Apple MainStage 3.1 - Live performance t...
Love the sound you got on your recording? MainStage 3 makes it easy to bring all the same instruments and effects to the stage. Everything from the Sound Library and Smart Controls you're familiar... Read more
Freeway Pro 7.0.2 - Drag-and-drop Web de...
Freeway Pro lets you build websites with speed and precision... without writing a line of code! With its user-oriented drag-and-drop interface, Freeway Pro helps you piece together the website of... Read more

Sentinel 4: Dark Star Adds New Campaign...
Sentinel 4: Dark Star Adds New Campaign and More Posted by Ellis Spice on January 27th, 2015 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Wheel & Deal Review
Wheel & Deal Review By Tre Lawrence on January 27th, 2015 Our Rating: :: SIMPLE FUNUniversal App - Designed for iPhone and iPad A simple arcade shooter that has a retro feel.   | Read more »
This Week at 148Apps: January 19-23, 201...
Warm Your Winter With New Apps!   How do you know what apps are worth your time and money? Just look to the review team at 148Apps. We sort through the chaos and find the apps you’re looking for. The ones we love become Editor’s Choice, standing out... | Read more »
Eggmaster Review
Eggmaster Review By Jennifer Allen on January 26th, 2015 Our Rating: :: BRIEFLY COMPELLINGUniversal App - Designed for iPhone and iPad Tap like crazy to gain eggs, so that you can buy upgrades to gain more eggs, and so on. It... | Read more »
Cloudy Or Dry – Funny Or Die Release a W...
Cloudy Or Dry – Funny Or Die Release a Weather App Posted by Ellis Spice on January 26th, 2015 [ permalink ] iPhone App - Designed for the iPhone, compatible with the iPad | Read more »
Mediocre, the Team Behind Smash Hit, is...
Mediocre, the Team Behind Smash Hit, is Teasing Their Latest Unnamed Project Posted by Jessica Fisher on January 26th, 2015 [ permalink ] | Read more »
Heroes of Gaia Review
Heroes of Gaia Review By Campbell Bird on January 26th, 2015 Our Rating: :: TIMERS OF MIGHT AND MAGICUniversal App - Designed for iPhone and iPad This free-to-play rpg looks a lot like Heroes of Might and Magic, but it’s poor... | Read more »
Choice Provisions is Set to Launch Destr...
Choice Provisions is Set to Launch Destructamundo on iOS This Month Posted by Tre Lawrence on January 23rd, 2015 [ permalink ] Choice Provisions – home stable to | Read more »
King of Thieves – An Interview With Zept...
Ahead of the release of ZeptoLab’s King of Thieves, we were able to ask ZeptoLab’s co-founder, Semyon Voinov, a few questions about the inspiration behind the game and what that means for the Cut the Rope franchise. | Read more »
Handle Review
Handle Review By Jennifer Allen on January 23rd, 2015 Our Rating: :: SPEEDY ORGANIZINGUniversal App - Designed for iPhone and iPad Handle is a very convenient way of juggling your emails, To Do list, and Calendar all through one... | Read more »

Price Scanner via MacPrices.net

Save up to $340 on iMacs with Apple Certified...
The Apple Store has Apple Certified Refurbished iMacs available for up to $340 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free. These are the best prices on... Read more
AppleCare Protection Plans on sale for up to...
B&H Photo has 3-Year AppleCare Warranties on sale for up to $105 off MSRP including free shipping plus NY sales tax only: - Mac Laptops 15″ and Above: $244 $105 off MSRP - Mac Laptops 13″ and... Read more
Apple refurbished Time Capsules available sta...
The Apple Store has certified refurbished Time Capsules available for up to $60 off MSRP. Apple’s one-year warranty is included with each Time Capsule, and shipping is free: - 2TB Time Capsule: $255... Read more
3TB AirPort Time Capsule on sale for $349, $5...
B&H Photo has 3TB AirPort Time Capsules on sale for $349 including free shipping plus NY sales tax only. Their price is $50 off MSRP, and it’s the lowest price available for this model (except... Read more
16GB iPad Air 2 on sale for $446, save $53
Walmart has 16GB WiFi iPad Air 2s on sale for $53 off MSRP on their online store. Choose free shipping or free local store pickup (if available). Sale prices available for online orders only, in-... Read more
Save up to $300 on a new Mac, $30 on an iPad,...
Purchase a new Mac or iPad at The Apple Store for Education and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free,... Read more
MasterCard Brings Contactless Payment, Apple...
MasterCard, the official card of the Waste Management Phoenix Open, and the PGA TOUR are bringing the latest payment technology to the spectator experience with the introduction of contactless... Read more
Petitioning Dropbox For Mac OS X 10.4 and 10....
Last week Dropbox announced to its users that app support for Mac OS X 10.4 and 10.5 will end May 18 — disappointing news for those of us who are still getting useful service out of older PPC Macs... Read more
Stop Street Harassment, Bullying, and Assault...
The STOP-ATTACK (http://www.stop-attack.com) app will leverage smartphone technology to make the world a safer place. Whether it’s bullying, street harassment or something even more sinister, the app... Read more
Stir Kinetic Desk M1 Standing Or Sitting Desk...
The age of the standing desk is upon us, and according to medical research, it’s arriving none too soon. The World Health Organization (WHO), reports that 60 to 85 percent of people worldwide lead... Read more

Jobs Board

Detailer *Apple* Ford Body Shop / Collision...
Apple Automotive is one of the fastest growing dealer…and it shows. Consider making the switch to the Apple Automotive Group today! At Apple Automotive , Read more
*Apple* Acura/Subaru Service Technicians - A...
Apple Automotive is one of the fastest growing dealer…and it shows. Consider making the switch to the Apple Automotive Group today! At Apple Automotive , Read more
Business Development Manager - *Apple* Pay...
**Job Summary** Apple Pay is seeking an experienced business development manager to support the identification, recruitment, negotiation and ongoing management of Read more
*Apple* Solutions Consultant (ASC)- Retail S...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
*Apple* Solutions Consultant - Retail Sales...
**Job Summary** As an Apple Solutions Consultant (ASC) you are the link between our customers and our products. Your role is to drive the Apple business in a retail Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.