Finding a tracker when DHT is disabled

[Aaron.Walkhouse]

That doesn't make any sense, but operators of private trackers usually lack that to begin with.

TPB didn't block private torrents after switching to magnets.  TPB blocked private torrents to encourage DHT and torrents without trackers.  The magnet protocol has nothing to do with that.  In fact, this was done before they started hosting magnet links for torrents.  The only thing that happened after switching to magnets was that TPB stopped serving the torrent file when the swarm size was greater than 10.  And then eventually stopped serving torrent files entirely.

Unauthorized leeching is usually enforced by access keys in announce URLs.  You can't find peers on a private torrent without a working tracker, so you can't request the metadata to begin with.

On the other hand, torrent files are quite easy to share.  One would think magnet links would be preferred over torrent files given the ease of blocking an access key.  It is silly to think that a private site can somehow kill a torrent by blocking the magnet protocol.  Kill sharing of the hash in the tracker if you want to do that.

Obviously, if a client developer chooses to disable the magnet protocol for private torrents that is their choice.  I'd consider that a bug.  It offers no security or control.

Don't forget that torrents always carry the metadata. ‌ Only magnets require a metadata download.

This plugs a workaround for when a private tracker stops serving a particular torrent, as you described.
Even on public trackers, magnets can't be permitted to violate the integrity of a private swarm by enabling
any of the three alternate tracking methods.

It's a deliberate feature of the BT protocol. ‌ Magnets cannot lock out DHT, PEX or Local Peer Discovery
so downloads through private torrents are blocked by seeds and peers when attempted, even metadata. ‌
Competent BT apps must comply or it would be major news and everyone would block such rogue apps.

This problem is one of the reasons private torrents were blocked. ‌Ask some of the older TPB admins
and maybe one of them might remember this was one of the problems after we started using magnets.
I'd refer you to posts of that time but we lost the forums a few years ago. ‌ ;]

[GJ6643KM]

Thanks to all who replied. I now have the files, thanks to the links supplied by Aaron.Walkhouse, and that's something I didn't think would happen.

[connor17]

Private flag is just another form of DRM. A particularly idiotic one.

File sharing is against all that.

[Kingfish]

Magnets don't block or allow anything because a magnet is just the info hash of the torrent plus a list of trackers or nodes that allows a client to search the available swarms for the particular torrent then it's up to the found clients whether to serve the torrent file or not and whether to respect the private flag or not and it is a choice in respecting the private flag.

[Aaron.Walkhouse]

Any apps that fail to respect the private flag in this way would enable rampant leaking from private trackers and their communities.
Such rogue apps would get a lot of negative attention and be quickly banned everywhere. ‌ This is why no such app exists to date.
Not one serious developer would risk getting such a bad reputation because it would follow him (and all of his products) to his grave. ‌ ‌

[connor17]

Any apps that fail to respect the private flag in this way would enable rampant leaking from private trackers and their communities.
Such rogue apps would get a lot of negative attention and be quickly banned everywhere. ‌ This is why no such app exists to date.
Not one serious developer would risk getting such a bad reputation because it would follow him (and all of his products) to his grave. ‌ ‌

That's a pretty idiotic answer.

No one should give a flying fuck about private sites moronic rules, or their circlejerking so called communities.

If torrent clients respect private flag is because if someone wants that shit then to each their own, not because the client would get banned in some stupid site. In fact, most clients are already banned there.

[Kingfish]

Any apps that fail to respect the private flag in this way would enable rampant leaking from private trackers and their communities.
Such rogue apps would get a lot of negative attention and be quickly banned everywhere. ‌ This is why no such app exists to date.
Not one serious developer would risk getting such a bad reputation because it would follow him (and all of his products) to his grave. ‌ ‌

That's a bit of a dumb reply, the private flag infers no privacy and is simple to circumvent and really should have been retired long ago given SSL torrents exist where certificates can be issued and revoked.

I'm really at a loss why you think a client that chooses to not respect the 'private' flag could be 'banned everywhere' given clients self identify themselves in the first place.

[Moe]

It's a deliberate feature of the BT protocol. ‌ Magnets cannot lock out DHT, PEX or Local Peer Discovery
so downloads through private torrents are blocked by seeds and peers when attempted, even metadata. ‌
Competent BT apps must comply or it would be major news and everyone would block such rogue apps.

This problem is one of the reasons private torrents were blocked.  ‌Ask some of the older TPB admins
and maybe one of them might remember this was one of the problems after we started using magnets.
I'd refer you to posts of that time but we lost the forums a few years ago. ‌ ;]

You really fail to understand how magnet links work.  Your problem is that you cannot separate the functionality of metadata acquisition from peer discovery.

Magnets cannot lock out DHT, PEX, or anything else because it has nothing to do with the protocol.  (Read for youself)  The magnet protocol doesn't even enter the picture until two peers are already connected.  Since no peer that has metadata with the private flag set is going to be advertising itself anywhere but by tracker, a magnet link is useless if it doesn't also include the same tracker.  (Read for yourself)  You following yet?  That means the two peers got connected in the first place because they both already had knowledge of the active tracker used by the swarm for the hash in question.  The very nature of peer discovery for private flagged torrents already guarantees a torrent can't leak using the magnet protocol.  You demonstrate how ignorant private tracker operators blacklisting clients they consider "rogue" is bad for the entire community.

I don't need to ask the TPB admins about their experience with magnet links because I was there.  I was also there when private torrents were no longer allowed, and as I already told you, the two things are not related.  They are two entirely independent extensions of the bittorrent protocol.

[Aaron.Walkhouse]

Its not about the magnets, it's all happening within torrent apps which are working as designed. ‌
If people could circumvent private torrents simply by starting with a magnet instead of a torrent
it would be commonplace by now and private trackers and their communities could not exist at all. ‌‌‌‌

Magnets cannot lock out DHT, PEX, or anything else because it has nothing to do with the magnet
URI protocol. ‌‌‌‌ They cannot honour the security requirements of BT because magnet is not a BT
protocol at all, and never was. ‌‌‌‌ BT apps use magnets but don't stop being true BT apps if they stop
doing so, even if it's hard to imagine dropping support for them at this late date.

Magnets are URIs used to initiate a download, so saying "The magnet protocol doesn't even enter
the picture until two peers are already connected." demonstrates a basic misunderstanding of their use. ‌‌
Magnets are a URI protocol used just to start a download, not a BT protocol or BEP enhancement used
to actually carry out torrenting functions. ‌‌‌ Apps starting with just a magnet always start by contacting
trackers, polling DHT and sometimes LANs in order to find a peer or seed in order to use PEX and get the
metadata with BT protocols. ‌‌‌ Peers don't connect until found, and that's when actual BT protocols come
into use for the rest of the download.  This is why BT magnets can never be adapted or updated to enable
use in private swarms. ‌‌‌ They are a generic, and somewhat limited, ad-hoc use of the magnet URI protocol
which is itself used for many purposes other than starting BT downloads. ‌‌‌‌ They do no interpeer negotiation
as that's outside the scope.

If magnets could be used as you guys assumed, someone inside any private community seeking to leak
a private swarm wouldn't even need to reveal what tracker was originally involved because he could simply
use any tracker and the other three methods to start a public swarm. ‌‌‌‌ The fact that he can't get the metadata
to load in a download started by a magnet link with the same hash value blocks the leak before it can start. ‌‌
Conversely, if he tries to add a public tracker to his already-running download, it still doesn't help magnet users
because they can't get the metadata. ‌‌‌ Even if he included the correct tracker with the correct password in the
magnet URI, all active peers and seeds in the swarm would detect the lack of security in the incoming peer
during protocol negotiations for the metadata download; thus that download would silently fail. ‌‌‌‌ The transfer of
metadata necessary to breach privacy is blocked in all proper apps. ‌‌‌‌ This is deliberate, and all the app developers
would willingly confirm that this is what they will always do in cases like this.

The very nature of peer negotiations for private flagged torrents already guarantees a torrent can't leak using the
magnet protocol. ‌‌‌‌ This is because intruders explicitly can't get the metadata because properly-written apps recognize
they aren't honoring peer discovery restrictions necessary to maintain that privacy. ‌‌‌‌ The apps are communicating
between themselves whether security is being maintained and those that are capable of activating DHT, PEX and
Local Discovery in a private swarm are automatically locked out from downloading metadata of that particular swarm. ‌‌‌‌‌‌‌‌
Peer discovery and metadata acquisition are two different actions using several different torrent protocols and
all BT apps check to make sure security is maintained according to the protocols before metadata is transferred
to incoming peers. ‌‌‌‌ Even if an unauthorized leech finds all the peers and seeds, it's no go. ‌‌‌‌ It's as simple as that.

This is why OP had the problems she described and that's why my suggestions helped her finish her downloads,
both of which are proof of the simple, straightforward core security built into all BT apps as I have described here.
If you don't believe her (or me) feel free to ask an actual BT developer. ‌‌‌‌‌ He'll tell you the same, perhaps a bit more clearly;
though you might have to suffer him snapping off a slightly more concise explanation in your general direction. ‌‌‌‌‌ ‌‌‌‌‌
Now, since you made me work on a Saturday night, you each owe me a beer. ‌‌‌‌‌ Feel free to grumble while you pour those pints. ‌‌‌‌‌ ‌‌‌‌‌

[Kingfish]

Magnets are not used to initiate a download at all they are used to fetch the metadata for the torrent file and that is all.