how to generate a valid private-key + recv address in PHP?

[hamdi]

what´s the easiest way to generate a priv-key + recv-addr in php?

so i can make sites which accept bitcoin without running a daemon...

i want to do what bitaddress.org does in js, but in php.


don´t tell me to not keep private key on server... i will care about that...
i really want to do this in php, so please don´t give any arguments against my plan.

[1714875579]

1714875579

[1714875579]

1714875579

[lulzplzkthx]

Are you putting out a bounty for this?

[gweedo]

https://github.com/mikegogulski/bitcoin-php/blob/master/src/bitcoin.inc#L567

this uses a bitcoind as a backend and just queries that to get a new address so that could be an answer

[hamdi]

"generate priv-key and recv-addr in pure php without a btc-daemon or any other external requirements" 


bounty is 1 BTC to the first poster who posts a working php code here.

i know there is already some code around, but i just can´t find it.

[lulzplzkthx]

https://github.com/mikegogulski/bitcoin-php/blob/master/src/bitcoin.inc#L567

this uses a bitcoind as a backend and just queries that to get a new address so that could be an answer

I think hamdi's whole price is that he doesn't want to have to use bitcoind. And he doesn't have to. Now whether someone is going to write a script for him for free or not is the question.

[hamdi]

read, i set a bounty of 1 btc

[Stephen Gornick]

Incidentally, a Python version here:

 - http://bitcointalk.org/index.php?topic=84238

[gweedo]

http://bitcoin.stackexchange.com/questions/2289/php-script-to-create-private-key-public-address

bitcoin address is in the sig

[crazy_rabbit]

How did this work out? I would be interested in seeing exactly how you did it in the end.

[hamdi]

i use vanitygen in the back now

[kjj]

By the way, this is possible to do entirely in PHP, no calls to an external program.  You need a PHP library for doing EC math (there is one, LGPL), the curve definition for secp256k1 (copies of SEC2 are available for free on the web) and a little code to glue it all together.

The nice part is that if you do it all internally, you can specify the private key rather than asking the program for one at random.

[1541]

But there is no real "out of the box" PHP solution ready, right?
As most PHP based onlineshops (oscommerce, xtcommerce, zen-cart,...) run on a shared webspace, they would really benefit from a solution that does not rely on "bitcond" running as a service (or external server).

[kjj]

But there is no real "out of the box" PHP solution ready, right?
As most PHP based onlineshops (oscommerce, xtcommerce, zen-cart,...) run on a shared webspace, they would really benefit from a solution that does not rely on "bitcond" running as a service (or external server).

If you don't trust the host that runs your web store with your wallet, you really shouldn't trust it with the stuff that your wallet it made of either.

[hamdi]

i now use vanitygen via exec(); from php.
i then present the enduser with the bitcoin-address where he can pay his money,
at the same time the private-key is sent to an off-site bitcoind to be imported there.

[kjj]

i now use vanitygen via exec(); from php.
i then present the enduser with the bitcoin-address where he can pay his money,
at the same time the private-key is sent to an off-site bitcoind to be imported there.

You'd be better off generating the pair remotely, and pulling the address into the customer-facing server.

The stuff that you don't want stolen is being created in the place that you are worried about it being stolen from.  That isn't a great idea, even if you delete it right away.

[scintill]

For the challenge and to learn more about Bitcoin, I implemented this in pure PHP (bcmath extension required, but I think that's pretty standard. Edit: Goes much faster with GMP extension!)  Please check it over yourself before using it!  I checked several keypairs with Casascius' address utility and they look good, but I'm not an expert, and there aren't real solid tests of the code.  Most of the work is by a pre-written ECC lib I found.

Anyway, the code, with a demo embedded, is at https://gist.github.com/3549107.  It is a little slow right now but could be sped up by using GMP instead of bcmath.  I don't know if anyone still cares or if the bounty has been claimed, but it'd be nice to have.

If there's interest, let me know, and I will extend and/or test it better.

Edit: Cleaned up the code and made it use GMP if possible, as it is much much faster.  Also found ways to use the ECC lib's helper functions more, so there is less code.

[payb.tc]

thanks, i care, and look forward to reviewing your work.

[BCB]

scintill

Works like a charm.    Is there any more info on how to generate a sufficient amount of entropy when generating key pairs for real world use (line 42).

Thanks!

[kjj]

scintill

Works like a charm.    Is there any more info on how to generate a sufficient amount of entropy when generating key pairs for real world use (line 42).

Thanks!

Your best bet is probably to fopen /dev/random and read 32 bytes from it.  Be warned that /dev/random will stall until it comes up with enough entropy to complete your request.  Check  /proc/sys/kernel/random/entropy_avail first, or use /dev/urandom (unsafe).

[scintill]

scintill

Works like a charm.    Is there any more info on how to generate a sufficient amount of entropy when generating key pairs for real world use (line 42).

Thanks!

Your best bet is probably to fopen /dev/random and read 32 bytes from it.  Be warned that /dev/random will stall until it comes up with enough entropy to complete your request.  Check  /proc/sys/kernel/random/entropy_avail first, or use /dev/urandom (unsafe).

Yeah, that sounds good to me.  I didn't know about that proc file, that's cool.

Glad it's working for you, BCB.