Topic: Python Bitcoin ECC library, supports signing, transactions, determinstic wallets - page 3. (Read 11437 times)

If you want fast I strongly recommend you look at the C++ -based libbitcoin and sx: http://bitcoinmagazine.com/what-libbitcoin-and-sx-are-and-why-they-matter/ sx doesn't support elliptic curve arithmetic or ECDSA message signing, but it's great for the actual Bitcoin stuff!

And I realize there are plenty of inefficiencies in my code as used above with converting between numbers and hex and back. I'm deliberately targeting developer ease of use. No dependency-chasing, no ./configure, make, sudo make install, just a Python file that you can even copy+paste single functions from.

Nice, congratulations. Though I would've suggested a different language cause simply Python ain't all that fast when it comes to these expensive operations there.

I've been writing my own Python library for handling Bitcoin elliptic curve arithmetic for a while now, and just yesterday I made a serious push to have it include many more features. It now supports compressed keys, RFC6979 deterministic ECDSA message signatures (compatible with Electrum; see tests.py), transaction construction and signing and even Electrum-style wallets.

Here's the repo: https://github.com/vbuterin/pybitcointools

I deliberately designed the library to be simple and no-nonsense. No hundred-line monolithic functions, no classes, no wrapper objects, just hex/binary/numbers in and hex/binary/numbers out. You don't need to spend a lot of time "learning" it; no matter what format your data uses, there's some way of handling it in there somewhere. Note that this is NOT a fully functional wallet; it does not support transaction generation or verification, networking or anything to do with blocks. You still need *coind or *coin-qt along with the importprivkey command to do that. It's not a full node, but does have the basic features for constructing Bitcoin transactions and includes two functions for fetching history and pushing transactions with blockchain.info.

Here are some basic usage scenarios:

> from pybitcointools import *
> priv = sha256('some big long brainwallet password')
> priv
'57c617d9b4e1f7af6ec97ca2ff57e94a28279a7eedd4d12a99fa11170e94f5a4'
> pub = privtopub(priv)
> pub
'0420f34c2786b4bae593e22596631b025f3ff46e200fc1d4b52ef49bbdc2ed00b26c584b7e32523 fb01be2294a1f8a5eb0cf71a203cc034ced46ea92a8df16c6e9'
> addr = pubtoaddr(pub)
> addr
'1CQLd3bhw4EzaURHbKCwM5YZbUQfA4ReY6'

Transaction stuff:


> h = history(addr)
> h
[{'output': u'97f7c7d8ac85e40c255f8a763b6cd9a68f3a94d2e93e8bfa08f977b92e55465e:0', 'value': 50000, 'address': u'1CQLd3bhw4EzaURHbKCwM5YZbUQfA4ReY6'}, {'output': u'4cc806bb04f730c445c60b3e0f4f44b54769a1c196ca37d8d4002135e4abd171:1', 'value': 50000, 'address': u'1CQLd3bhw4EzaURHbKCwM5YZbUQfA4ReY6'}]
> outs = [{'value': 90000, 'address': '16iw1MQ1sy1DtRPYw3ao1bCamoyBJtRB4t'}]
> tx = mktx(h,outs)
> tx
'01000000025e46552eb977f908fa8b3ee9d2943a8fa6d96c3b768a5f250ce485acd8c7f79700000 00000ffffffff71d1abe4352100d4d837ca96c1a16947b5444f0f3e0bc645c430f704bb06c84c01 00000000ffffffff01905f0100000000001976a9143ec6c3ed8dfc3ceabcc1cbdb0c5aef4e2d028 73c88ac00000000'
> tx2 = sign(tx,0,priv)
> tx2
'01000000025e46552eb977f908fa8b3ee9d2943a8fa6d96c3b768a5f250ce485acd8c7f79700000 0008b483045022100fc9ec3f6c66f630604e76309092ae00b48d39a83f8683bbf9d6310084e70ea bd022058333d7a1d2158529ce39f9b48dea23dedefbe85028cdceab34e1ee9b1518c3201410420f 34c2786b4bae593e22596631b025f3ff46e200fc1d4b52ef49bbdc2ed00b26c584b7e32523fb01b e2294a1f8a5eb0cf71a203cc034ced46ea92a8df16c6e9ffffffff71d1abe4352100d4d837ca96c 1a16947b5444f0f3e0bc645c430f704bb06c84c0100000000ffffffff01905f0100000000001976 a9143ec6c3ed8dfc3ceabcc1cbdb0c5aef4e2d02873c88ac00000000'
> tx3 = sign(tx2,1,priv)
> tx3
'01000000025e46552eb977f908fa8b3ee9d2943a8fa6d96c3b768a5f250ce485acd8c7f79700000 0008b483045022100fc9ec3f6c66f630604e76309092ae00b48d39a83f8683bbf9d6310084e70ea bd022058333d7a1d2158529ce39f9b48dea23dedefbe85028cdceab34e1ee9b1518c3201410420f 34c2786b4bae593e22596631b025f3ff46e200fc1d4b52ef49bbdc2ed00b26c584b7e32523fb01b e2294a1f8a5eb0cf71a203cc034ced46ea92a8df16c6e9ffffffff71d1abe4352100d4d837ca96c 1a16947b5444f0f3e0bc645c430f704bb06c84c010000008c493046022100da7fa563ce34af5a4c 8167a2978cb5517ded494e52a29ea4103ff2c67bce77c102210094a18bda1109591a82d5cf5e444 6b12b3c399401c0f668755ac7f614eb3baa7701410420f34c2786b4bae593e22596631b025f3ff4 6e200fc1d4b52ef49bbdc2ed00b26c584b7e32523fb01be2294a1f8a5eb0cf71a203cc034ced46e a92a8df16c6e9ffffffff01905f0100000000001976a9143ec6c3ed8dfc3ceabcc1cbdb0c5aef4e 2d02873c88ac00000000'
> pushtx(tx3)
'Transaction Submitted'

ECDSA (Electrum-compatible):

> sig = ecdsa_sign("Hallo world",sha256("123"))
> sig
'G9vmnqdlS9hmP7qT6ReRJEqldYn7f6xc47ado3zg7g4LKpLgVmpmSttDNAAPSizww7zzKDamsyD7bhh fAqaAJ0s='
> ecdsa_verify("Hallo world",sig,privtopub(sha256("123")))
True
> ecdsa_verify("Hallo world!",sig,privtopub(sha256("123")))
False
> ecdsa_recover("Hallo world",sig)
'04be686ed7f0539affbaf634f3bcc2b235e8e220e7be57e9397ab1c14c39137eb43705125aac75a 865268ef33c53897c141bd092cf4d1a306b2a57e37e1386826d'
> privtopub(sha256("123"))
'04be686ed7f0539affbaf634f3bcc2b235e8e220e7be57e9397ab1c14c39137eb43705125aac75a 865268ef33c53897c141bd092cf4d1a306b2a57e37e1386826d'

Electrum:

> seed = sha256("cow")[:32]
> mpk = electrum_mpk(seed)
> for i in range(5): print electrum_privkey(seed,i,0), pubkey_to_address(privtopub(electrum_privkey(seed,i,0)))
daa19f768ea1a7bc8e33d83f9401ef237f5164ce39bf8000ec9630d088cec028 1GG9cGb7KW6qNBCxcU7Y3NH3mPRz9YSxgG
c45ad49da1ccb0ba30258902ed3de66af571de7421f9c73ffc0a8c2bde9ca596 19zxmnE4hmTwPFxhoDAxjtfnKQcRES4Sm2
c31100a56692314248a73f29b767ca252c3847eae15ce5d06e7e7f67a63ee5df 17mJpsyEVykxuf5H4YWsyhatXFyuJmkuoh
302362a97a2db566c5c65b875388db7cce246355faa72f15b486111c2f380bf3 16PGWQwcXM37iY7dPHqqVFit4GXsifRuAM
869424a50260cca7a7fa475c85e48ddf0e47abb0474df59ee45e72e6b95c8333 15QgAJmroGtExvVqVd8MGs1ZZvwYsk39i7
> for i in range(5): print pubkey_to_address(electrum_pubkey(mpk,i,0))
1GG9cGb7KW6qNBCxcU7Y3NH3mPRz9YSxgG
19zxmnE4hmTwPFxhoDAxjtfnKQcRES4Sm2
17mJpsyEVykxuf5H4YWsyhatXFyuJmkuoh
16PGWQwcXM37iY7dPHqqVFit4GXsifRuAM
15QgAJmroGtExvVqVd8MGs1ZZvwYsk39i7

Much faster Electrum by precomputing the secret exponent:

> seed = sha256("cow")[:32]
> secexp = electrum_stretch(seed)
> for i in range(5): print electrum_privkey(secexp,i,0), pubkey_to_address(privtopub(electrum_privkey(secexp,i,0)))
daa19f768ea1a7bc8e33d83f9401ef237f5164ce39bf8000ec9630d088cec028 1GG9cGb7KW6qNBCxcU7Y3NH3mPRz9YSxgG
c45ad49da1ccb0ba30258902ed3de66af571de7421f9c73ffc0a8c2bde9ca596 19zxmnE4hmTwPFxhoDAxjtfnKQcRES4Sm2
c31100a56692314248a73f29b767ca252c3847eae15ce5d06e7e7f67a63ee5df 17mJpsyEVykxuf5H4YWsyhatXFyuJmkuoh
302362a97a2db566c5c65b875388db7cce246355faa72f15b486111c2f380bf3 16PGWQwcXM37iY7dPHqqVFit4GXsifRuAM
869424a50260cca7a7fa475c85e48ddf0e47abb0474df59ee45e72e6b95c8333 15QgAJmroGtExvVqVd8MGs1ZZvwYsk39i7

BIP32:

> bip32_master_key('123456789')
'xprv9s21ZrQH143K2zm1WhDFQqHVdgzoyBWfghiTfgdVJDSjZtTupL9eeg7391hLNjHQNAbd1qLobce ZcaYvrKZ81E3SwtiZ2UbPsP2zm9HeDJo'
> bip32_ckd(bip32_master_key('123456789'),0)
'xprv9ujNqB68cg8G1owbyxEwLHMBYbB1RCyrcra4i8BciNhBrsWeQaEj8FBPNnRmGedK1Q9A5DD3vLe c8me5pBPSwdhckMPQPTWBMtiesu688LN'
> bip32_extract_key(bip32_ckd(bip32_privtopub(bip32_master_key('123456789')),0))
'02e7f3eb95c70480f3f850198017644a84654325b2a4b038268546ea60c1814f6f'
> bip32_extract_key(bip32_privtopub(bip32_ckd(bip32_master_key('123456789'),0)))
'02e7f3eb95c70480f3f850198017644a84654325b2a4b038268546ea60c1814f6f'
> privtopub(bip32_extract_key(bip32_ckd(bip32_master_key('123456789'),0)))
'02e7f3eb95c70480f3f850198017644a84654325b2a4b038268546ea60c1814f6f'

(Those are compressed public keys, which BIP0032 makes standard)

This is still an early work in progress; ideally, with help from others, I'd like to this extended to handle more networking options than just blockchain.info, and serve as a universal altcoin light client. That's a far-off goal though; better have the more basic features ironed out first. Feel free to provide any suggestions!