Verifying a signed message *without* a Bitcoin client installed?

bit22gen

jr. member

Activity: 45

Merit: 1

Quote from: themgp on June 01, 2013, 08:13:18 PM

If I have a Bitcoin address and a message signed with the private key of that address, is there a way to verify the signature with standard Unix commands?

bitsig (C++) can verify signatures:

http://bitcoin-gen.org/

Example:

$ bitsig verifyRaw "test" G93M44UVAiOAe7do7TJbtFrvedSpjoq6HFzCT0KZZW07/TvpE/qXxiZf6q7OV4nIqYkq9DDYPbvYTemsmpb0kbk= 17RjaCGZQbe2Cw984YdWcMcWDgM86kM7EN
Verifying raw message: test
Verifying signature...
Signed by the address: 17RjaCGZQbe2Cw984YdWcMcWDgM86kM7EN

BitTalkyy

newbie

Activity: 28

Merit: 0

Check my tutorial with PHP here -> https://bitcointalksearch.org/topic/verify-a-signed-message-in-php-without-downloading-anything-1210197

rjmacarthy

newbie

Activity: 45

Merit: 0

I'd use bitcore.io to do this.

http://bitcore.io/api/transaction/transaction.html#Transaction#verifySignature

Javascript framework can be installed locally or using node.js.

Hope this helps.

UserVVIP

sr. member

Activity: 294

Merit: 250

It should be pretty easy to do either way.

jonald_fyookball

legendary

Activity: 1302

Merit: 1004

Core dev leaves me neg feedback #abuse #political

is this done in PHP?

if not, i can do it, is there a bounty?

gweedo

legendary

Activity: 1498

Merit: 1000

If anyone wants apicoin can do many verifications of signatures at once, https://apicoin.io/api/v1/doc/#verifymessage

the_beast

full member

Activity: 145

Merit: 102

Maybe it's one more tool for handling signatures, but you could try FSV. This is a new multiple-platform GUI soft for PC. It's a pretty handy tool for signed messages checking.

https://bitcointalksearch.org/topic/m.6904979

scintill

sr. member

Activity: 448

Merit: 254

Quote from: jackjack on December 15, 2013, 10:12:08 AM

Who's the guy?
Is he currently registered?

I was respecting privacy, but on second thought I don't think he would mind. His name is Gregor Volkmann and his site is at http://gregor.volkmann.me/ . He contacted me by email so I don't have a username, and I couldn't find one with search. I haven't heard from him since telling him I posted, so I guess he hasn't registered. He probably only would have posted the link, but looking at his home page he seems open to being contacted, if people have questions or whatnot.

jackjack

legendary

Activity: 1176

Merit: 1255

May Bitcoin be touched by his Noodly Appendage

Quote from: scintill on November 29, 2013, 10:06:25 PM

I've been asked by someone in newbie jail, or unable to register, to post here this online signature verification tool he created: coinig.com. (Some CYA: this is not an endorsement of the correct functionality, security, privacy, etc. of the tool, just sharing a link.)

Who's the guy?
Is he currently registered?

vitruvio

sr. member

Activity: 850

Merit: 331

Congratulations for the good job.

Regards

scintill

sr. member

Activity: 448

Merit: 254

I've been asked by someone in newbie jail, or unable to register, to post here this online signature verification tool he created: coinig.com. (Some CYA: this is not an endorsement of the correct functionality, security, privacy, etc. of the tool, just sharing a link.)

scintill

sr. member

Activity: 448

Merit: 254

I finished the PHP code and put it at https://github.com/scintill/php-bitcoin-signature-routines for those who are interested.

Let me know if you find any problems or have questions.

scintill

sr. member

Activity: 448

Merit: 254

Quote from: Raoul Duke on June 11, 2013, 05:08:24 AM

I'll contribute 0.5 BTC for said bounty.

OK, thanks. I've got a first draft of some code that isn't working yet (the public-key recovery is a bit tricky), but should have most of what it needs. So I need to fix the bug, do some test cases, and clean it up. I'll try to have that done in the next day or so.

serp

sr. member

Activity: 245

Merit: 250

@serp

Quote from: akabmikua on June 11, 2013, 01:58:22 PM

Ok with JS? Why not try http://brainwallet.org/#verify

It works offline and is pretty good.

If you look at the source you will see that the brainwallet you linked uses the bitcoinlib-js linked above. Using the brainwallet software offline is fine if you are just doing one manually every now and then. If you are wanting to incorporate the functionality into your own code then it is probably best to use the core library or just write your own.

akabmikua

full member

Activity: 223

Merit: 100

Quote from: themgp on June 11, 2013, 12:24:22 PM

Quote from: serp on June 11, 2013, 11:06:22 AM

Quote from: themgp on June 11, 2013, 05:48:24 AM

We could also use a JavaScript library while everyone is at it.

This is covered by https://github.com/bitcoinjs/bitcoinjs-lib

Perfect.

Ok with JS? Why not try http://brainwallet.org/#verify

It works offline and is pretty good.

themgp

newbie

Activity: 56

Merit: 0

Quote from: serp on June 11, 2013, 11:06:22 AM

Quote from: themgp on June 11, 2013, 05:48:24 AM

We could also use a JavaScript library while everyone is at it.

This is covered by https://github.com/bitcoinjs/bitcoinjs-lib

Perfect.

serp

sr. member

Activity: 245

Merit: 250

@serp

Quote from: themgp on June 11, 2013, 05:48:24 AM

We could also use a JavaScript library while everyone is at it.

This is covered by https://github.com/bitcoinjs/bitcoinjs-lib

themgp

newbie

Activity: 56

Merit: 0

We could also use a JavaScript library while everyone is at it.

Raoul Duke

legendary

Activity: 1358

Merit: 1002

Quote from: scintill on June 11, 2013, 01:14:31 AM

I would do it in native PHP (a bignum extension required) with this ECC library for a bounty if anyone's interested.

I'll contribute 0.5 BTC for said bounty.

scintill

sr. member

Activity: 448

Merit: 254

I made a standalone C++ tool based on stripped-down bitcoin reference source. Just depends on OpenSSL. It should be easy to integrate into any language that can spawn another process and receive its return code, although a native library would probably be better if that's available to you. https://github.com/scintill/bitcoin-signature-tools

I just added a php demo: https://github.com/scintill/bitcoin-signature-tools/blob/master/tests/verifymessage.php

I would do it in native PHP (a bignum extension required) with this ECC library for a bounty if anyone's interested.

Topic: Verifying a signed message *without* a Bitcoin client installed? (Read 7434 times)

Topic: Verifying a signed message without a Bitcoin client installed? (Read 7434 times)