Wallet import/export: bitkeys format

[BitterTea]

There's other stuff in wallets, including preferences, address book entries for payees, and account information. bitkeys format won't be suitable for wallet backup if it loses all this.

That other stuff doesn't necessarily need to be in the same file or format as the private keys. I can see a use for exporting address book and account information, and I think those could be in a similar (CSV) format. I don't see much of a use for exporting settings, though it could be exported as well (INI format?).

[bitcoinex]

PEM structures have a lot of data we don't need,

?

We only need the 256-bit private key, not curve parameters, generator point and public key, which are stored in the OpenSSL structures (and some of those in .pem files too, judging by their size) as well.

(I'm not sure what it's all stored in a PEM.)

Using standart PEM gives an advantage: standard means to convert the key into binary format and then use this binary key for the barcode etc

[Pieter Wuille]

(I'm not sure what it's all stored in a PEM.)

Using standart PEM gives an advantage: standard means to convert the key into binary format and then use this binary key for the barcode etc

And I agree, but I'm not convinced it's the best way to handle wallet dumps.

Anyway, my current walletdump branch (https://github.com/sipa/bitcoin/tree/walletdump) contains a "dumppemkey <address>" RPC call, which exports in the standard PEM format... 720 characters per key (compared to the base58 representation of a (bitcoin-specific) private key, 51 characters).

It currently does not support importing keys, or extracting only the public key of an address.

[Luke-Jr]

Code:

MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="exportedWallet"

--exportedWallet
Content-Type: application/x-ecdsa-private-key
Content-Transfer-Encoding: base64
X-Bitcoin-Network-ID: <network id>
X-Bitcoin-First-Block: <block number>
X-Bitcoin-Txid: f2ed2f6cc779696969690696abababa4ccf185d478aa799eb7d3e561c77b1022
X-Bitcoin-Txid: f2ed2f6cc779696969690696abababa4ccf185d478aa799eb7d338712abff2b3
X-Bitcoin-Start-Block: <last block scanned>
X-Bitcoin-Wallet-Flags: <flags>
X-Bitcoin-Wallet-Label: <label>
X-Bitcoin-Wallet-Comment: <comment>

PGh0bWw+CiAgPGhlYWQ+CiAgPC9oZWFkPgogIDxib2R5PgogICAgPHA+VGhpcyBpcyB0aGUg
Ym9keSBvZiB0aGUgbWVzc2FnZS48L3A+CiAgPC9ib2R5Pgo8L2h0bWw+Cg==
--exportedWallet
Content-Type: application/x-ecdsa-private-key
Content-Transfer-Encoding: base64
X-Bitcoin-Network-ID: <network id>
X-Bitcoin-First-Block: <block number>
X-Bitcoin-Txid: f2ed2f6cc779696969690696abababa4ccf185d478aa799eb7d3e561c77b1024
X-Bitcoin-Txid: f2ed2f6cc779696969690696abababa4ccf185d478aa799eb7d338712abff2b4
X-Bitcoin-Start-Block: <last block scanned>
X-Bitcoin-Wallet-Flags: <flags>
X-Bitcoin-Wallet-Label: <label>
X-Bitcoin-Wallet-Comment: <comment>

PGh0bWw+CiAgPGhlYWQ+CiAgPC9oZWFkPgogIDxib2R5PgogICAgPHA+VGhpcyBpcyB0aGUg
Ym9keSBvZiB0aGUgbWVzc2FnZS48L3A+CiAgPC9ib2R5Pgo8L2h0bWw+Cg==
--exportedWallet--

[coga]

You know what this thing would be awesome for? Gift cards.

If you need to give someone, say, 5 BTC as a birthday gift, you:

- Generate public/private key pair
- Transfer 5 BTC to that pair
- Export (possibly with delete) the key from wallet
- Convert exported key to a QR code
- print the code on a postcard

I know, it's kinda geeky, but it could be awesome way to both give something of value, as well as get more people familiar with bitcoin

[Pieter Wuille]

You know what this thing would be awesome for? Gift cards.

If you need to give someone, say, 5 BTC as a birthday gift, you:

- Generate public/private key pair
- Transfer 5 BTC to that pair
- Export (possibly with delete) the key from wallet
- Convert exported key to a QR code
- print the code on a postcard

I know, it's kinda geeky, but it could be awesome way to both give something of value, as well as get more people familiar with bitcoin

See jgarzic's scratchoff patch: http://bitcointalk.org/index.php?topic=4555.0 and BitBills http://bitcointalk.org/index.php?topic=7724.0.

[LehmanSister]

I've though about it. It's a very simple way to avoid any parsing/escaping difficulty, while making it easy to extend it further afterwards. On the other hand, CSV is so simple that you don't even need any library for parsing.

Oh how I wish this were true (I used to believe this myself). The number of extremely bizarre CSV dialects I've encountered over the years occupies far too many brain cells. Salvation can oft be found here: http://docs.python.org/library/csv.html#csv.Dialect . I'm still running into occasional Excel CSV exports that break if there's a comma in a field (not that I'm implying that Excel is an example of stellar programming).