A brainwallet phrase (pre-BIP39 "passphrase -> key")

Before seed words (2011-2015) people typed any sentence into brainwallet.org or bitaddress.org's Brain Wallet tab and got a key: the private key is SHA-256 of the phrase bytes, no checksum, no stretching. Keybase's WarpWallet (2014) hardened that with scrypt and PBKDF2 and an e-mail salt. phrase-to-key does both; key-to-addresses then prints the addresses, compressed and uncompressed (brainwallet.org used uncompressed).

The phrase is used byte for byte: spaces, case and punctuation all matter, and every phrase yields a key, so a wrong phrase gives a wrong (empty) address rather than an error. Check the address against the one you funded.

./blocktools run 'phrase-to-key < /in/brainwallet.txt | key-to-addresses --chain btc'

(The vector is the xkcd "correct horse battery staple" brainwallet, drained in 2013: 1JwSSubhmg6iPtRjtyqhUYYH7bZg3Lfy1T.)

WarpWallet needs the e-mail (salt) too, so the input is a JSON line {"phrase":"...","salt":"[email protected]"}; the salt may be empty. scrypt N=2^18 is memory-hungry (a quarter gigabyte) and takes about a second per phrase. Vector: keybase/warpwallet test/spec.json #1 (1J32CmwScqhwnNQ77cKv9q41JGwoZe2JYQ).

./blocktools run 'phrase-to-key --scheme warpwallet < /in/warpwallet.json | key-to-addresses --chain btc'

--scheme all tries both. Other chains: key-to-addresses without --chain prints every chain, but brainwallets were a Bitcoin habit; an ETH brainwallet (sha256 of a phrase as the key) is the same bytes, so --chain eth works.

NOT BUILT: Electrum's or Armory's own passphrase stretching (those are wallet files: see input-electrum.md, input-armory.md), "sha256 twice" or salted home-made variants, and the brainwallet.org Armory and Electrum tabs. recover.sh cannot classify a free-text phrase (any sentence is one), so use the pipeline above.