How To Automate Bitcoin Payments For Website Sales??

[wumpus]

maybe if my site it self went and checked the block chain data, then i would only have to trust my self....

I think the best option would be a lightweight client that listens in on the P2P network and passively checks the block chain data and dispatches notifications for receives on a set of addresses. That prevents you from relying on a single point of failure.  

I mean, an external provider is easier to use, but what if bitcoinnotify is hacked? It could lie that it receives coins. The P2P network and block chain is in place exactly to prevent this kind of lying.

Don't get me wrong -- I do think bitcoinnotify is a great service, especially for testing and initial development. You can always switch to your own block chain listener later.

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[BitPay Business Solutions]

Adam,

check out

https://bit-pay.com

We let you price your items/cart in USD and we handle the rate conversion at the point of payment.  If you'd like to see it in action, visit these handful of merchants that are using it:

http://bitcoinconference.com

http://www.staremagazine.com/Store/PurchaseIssue.asp?IssueID=116

http://ogdogg.com

send me a PM if you have any questions.

Thanks!
Tony

[nmat]

...

I was surprised no one mentioned bit-pay yet 

[indicasteve]

I thought Josh was talking about the fact that the only authorization is your IP address:

All HTTP notifications are sent with the POST method from the IP 46.4.90.208.

You should check the request IP in your controller to ensure the notification actually comes from us.

...

Here is the example request you can expect:

POST http://www.yourstore.com/payment_notifications?type=payment_received&btc_amount=2.99&to_address=15fdhRDNYn4vbRztLS4hZeh9TtpNEMcikJ

Someone might be able to forge a 'payment sent' request to your user's website by simple spoofing your IP address since it appears there is no authentication or token or anything sent in the POST request itself to prevent a fake payment acknowledgement.

An IP address spoofing explanation is here:
http://www.shaadiya.com/ask/2007/06/15/how-to-spoof-ip-address-hackers-view-and-the-way-to-protect-sites-with-this-fake/

If I could spoof your address I could send fake payment acknowledgements to all your users.

But, I'll be honest, I only took a quick look at your docs and I don't know your system nor have I tried it yet so maybe I'm just blowing smoke out my ass.

But if I'm right, you should probably fix that.

issues worth noting.

any ideas on how to fix this issues?

maybe you could send me an encrypted password along with the other information.
on my side once i can check the password and know its not a fake

You need to sign the messages using a secret that only the sender and receiver knows.

You can do this by concatenating all the data you send into one long string then add a secrect code to the end of the string.

Then you do a SHA256 hash on the string and send the hash with the data.

The person on the other end who receives the data can do the same procedure ... concatenate all the data, add the secret, then get a hash.

If the sender's hash == the enduser's hash then the data must have come from the sender because only you and the sender should know the secret.

The secret is never sent to the receiver in the transaction.  Only the hash of data+secret is sent.

For further protection, add a timestamp to the data to ensure a unique hash will always be created.  The receiver can also check this timestamp to ensure it is a recent transaction.

For further protection against 'replay' attacks, the user can store all the hashes in a DB and reject any attempts to use the same hash twice.

[OgNasty]

www.bit-pay.com

[adamstgBit]

www.bit-pay.com

Bit-pay is now available to businesses in the United States

I'm from canada and want to price in btc and CND$

[Raoul Duke]

www.bit-pay.com

Bit-pay is now available to businesses in the United States

I'm from canada and want to price in btc and CND$

Kris, from http://walletbit.com made a Prestashop module that supports all currencies imaginable, using a mix of TradeHill API and google currency conversion calculator Pretty slick if you ask me.

[adamstgBit]

all considered i will go for the BitcoinNotify.com system

but i will handle it in a way that i can't get burnt

BitcoinNotify.com will send me a notification that a payment was sent.

with that information i can tell the customer that his order has went through and is now being processed

i can then check my wallet b4 i ship the item. (i think i would do this even if BitcoinNotify.com was 100% secure)

99.9% of the customer will have infact sent me the moeny

0.01% of the time i will e-mail the hacker explaining that he has to actually send me the funds b4 i send the item.

i can prove that the payment was not send by looking the block chain.

...

i will also consider using this http://walletbit.com

[kjj]

all considered i will go for the BitcoinNotify.com system

but i will handle it in a way that i can't get burnt

BitcoinNotify.com will send me a notification that a payment was sent.

with that information i can tell the customer that his order has went through and is now being processed

i can then check my wallet b4 i ship the item. (i think i would do this even if BitcoinNotify.com was 100% secure)

99.9% of the customer will have infact sent me the moeny

0.01% of the time i will e-mail the hacker explaining that he has to actually send me the funds b4 i send the item.

i can prove that the payment was not send by looking the block chain.

People need to understand that this step is very important, and should not be delegated lightly.

[BitcoinNotify.com]

You need to sign the messages using a secret that only the sender and receiver knows.

You can do this by concatenating all the data you send into one long string then add a secrect code to the end of the string.

Then you do a SHA256 hash on the string and send the hash with the data.

The person on the other end who receives the data can do the same procedure ... concatenate all the data, add the secret, then get a hash.

If the sender's hash == the enduser's hash then the data must have come from the sender because only you and the sender should know the secret.

The secret is never sent to the receiver in the transaction.  Only the hash of data+secret is sent.

For further protection, add a timestamp to the data to ensure a unique hash will always be created.  The receiver can also check this timestamp to ensure it is a recent transaction.

For further protection against 'replay' attacks, the user can store all the hashes in a DB and reject any attempts to use the same hash twice.

Thank you for pointing that out and providing an excellent solution.

Indeed, if someone would be able to both spoof the IP and guess the URL fake notifications could have been sent.

This is fixed now.

All HTTP notifications are signed with a secret token and timestamp. This works exactly as described above by indicasteve.

Here are the docs: https://bitcoinnotify.com/docs

[Serge]

With BitcoinNotify do all customers send their payments to a single bitcoin address that merchant provides?


Someone earlier in the thread mentioned "faking an IP address", could someone please explain how it's done?
I know with php's curl lib everything in http headers could be 'faked' except an IP address

[kjj]

With BitcoinNotify do all customers send their payments to a single bitcoin address?


Someone earlier in the thread mentioned "faking an IP address", could someone please explain how it's done?
I know with php's curl lib everything in http headers could be 'faked' except an IP address

You have to bypass most of the network stack so you can manually build and emit packets directly at a low level, either as IP packets or ethernet frames, depending on what you need to do.  You also need an ISP that doesn't do egress filtering, unless you are very close to either the recipient or the sender you are trying to spoof.

There are other things you need to do too, like guess the sequence numbers so that you can make it look like you completed the three way handshake even though the SYN-ACK went somewhere else.

[BitcoinNotify.com]

With BitcoinNotify do all customers send their payments to a single bitcoin address that merchant provides?

No, unless the Merchant really wants to.

BitcoinNotify will monitor all receiving addresses submitted by the Merchant and will deliver payment notifications.

Every Merchant pre-generates a set of Bitcoin receiving addresses on his own, using his Bitcoin client.

This small, one-time inconvenience gives the Merchant unmatched protection compared to storing wallet on the server and generating addresses on demand.

BitcoinNotify is a "keep your wallet disconnected from the network and sleep well" service for Merchants. This is in contrast to MyBitcoin and other available solutions.

earlier in the thread mentioned "faking an IP address", could someone please explain how it's done?

It's relatively hard but in principle possible to fake an IP address. This is why all notifications are signed with a secret token.

[Littleshop]

Can you make bitcoin notify work with opencart?

[BitcoinNotify.com]

Can you make bitcoin notify work with opencart?

I'd love to see a BitcoinNotify plugin for OpenCart.

While personally I must focus in the core service, I can offer any help necessary to someone willing to develop such a plugin.

[MrJoshua]

I'm hoping that this thread goes to show, that 3rd party services have security flaws, even when they say they don't. It is always you're own responsibility to verify the security of your money. You can't trust a sales pitch, however well intentioned.

I am surprised to discover that you can't check payments to random addresses remotely at the moment, so I've tried to give the dev team some encouragement to integrate that feature (which is already available in a patch).

You can use bitocind on a server and manage the funds entirely yourself. This is as easy as any web service using the json interface.  You can have a duplicate of the server's wallet on your own machine, and you can manually or procedurally sweep funds from the online wallet to a more secure wallet at any time.

3rd party solutions are NEVER going to be an easier way to bitcoin security. It is not possible to know all the security issues with a 3rd party solution, without access to their entire server/software stack, and significant knowledge of possible weakness (like IP masquerading). Which is of course harder then securing your own server.  You can always make your server at least as secure as any 3rd party server, and because unix security is a known problem you have lots of resources for improving it.

I think BitcoinNotify is probably a very good service that can help the bitcoin economy, and I want to see more bitcoin merchant related services. I'm glad they attempted to addressed one of the security issues quickly, but there is still the double spend attack which is quite a bit easer to exploit then IP masquerading (mybitcoin claims that is exactly what happened to them, losing more then 50% of all customers assets), and who knows how many other issues (how secure are their servers, are you really going to always check the sig on their POST request?). This may not be an issue for the OP because he can re-verify payments before shipping, but not all services have that window for additional verification. So please understand you ARE compromising your security by using a 3rd party, it is up to you to decide if the benefits out way the risk, and you must do so without a full knowledge of what risks that 3rd party is exposing you too.

As I said before, and everyone should know by now, there is no shortcut to security.

Understand first, trust second, and if you must trust someone trust a security professional who is working for you.

j

[nmat]

You are also compromising security if you don't trust a 3rd party. Not everyone is talented enough to secure a server properly. There must be a balance between these two things. It's not just "3rd party is all wrong, don't trust them".

[BitcoinLocator]

You are also compromising security if you don't trust a 3rd party. Not everyone is talented enough to secure a server properly. There must be a balance between these two things. It's not just "3rd party is all wrong, don't trust them".

And who's to say the 3rd party is any better at securing their servers?  You just don't know.  

The only time you can actually be demonstrably more secure by using a 3rd party is if the 3rd party provides an SLA (Service Level Agreement) that you can legally enforce in your jurisdiction wherein they agree to become liable for your losses if they screw up, only then is the risk transferred and you don't need to know if they have security flaws.

[BitcoinNotify.com]

3rd party solutions are NEVER going to be an easier way to bitcoin security. You can always make your server at least as secure as any 3rd party server, and because unix security is a known problem you have lots of resources for improving it.

I'm afraid most merchants are not security experts and operate on a string budget.

They need to outsource IT anyway.

The most common choice is probably between hiring a student or using an existing 3rd party solution.

Please get real.

[BitcoinNotify.com]

You can expect Bitcoin payment notification in seconds after your customer clicks "Send" button in his Bitcoin client. While technically the transaction is not confirmed by the Bitcoin network, for most purposes it is practical to consider it so. Support for "confirmed" transactions is being developed for those cases when you need to be 100% sure (and do accept delays).

Do you see it now?

Considering how many people trusted mybitcoin, and a startling willingness to abandon a key security feature of bitcoin I think it's important that everyone understand that security is a multifaceted problem.

Confirmed payments are now fully supported in BitcoinNotify.

Merchant decides how many confirmations are "enough" for his/her purpose.

It is also possible to order notifications on several confirmation levels, i.e. 0/unconfirmed for visual payment acceptance in the store, and 6 confirmations for actually shipping the item.

PS @MrJoshua: thanks for stressing the importance of security in this thread.