Bitcoin bash tools

Bitcoin-related functions in Bash.

Synopsis
Description
- Base-58
- bech32
- Wallet Import Format
- Extended keys
- Mnemonics
  - BIP-39
  - Major system
- Requirements
- TODO
- Feedback
- Related projects
- License
Synopsis
```
$ git clone https://github.com/grondilu/bitcoin-bash-tools.git
$ . bitcoin-bash-tools/bitcoin.sh

$ openssl rand 32 |wif

$ mnemonic=($(create-mnemonic 128))
$ echo "${mnemonic[@]}"

$ mnemonic-to-seed "${mnemonic[@]}" > seed
$ pegged-entropy {1..38} > seed

$ xkey -s /N < seed
$ ykey -s /N < seed
$ zkey -s /N < seed

$ bitcoinAddress "$(xkey -s /44h/0h/0h/0/0/N < seed |base58 -c)"
$ bitcoinAddress "$(ykey -s /49h/0h/0h/0/0/N < seed |base58 -c)"
$ bitcoinAddress "$(zkey -s /84h/0h/0h/0/0/N < seed |base58 -c)"


$ bip85 wif
$ bip85 mnemo
$ bip85 xprv

$ (cd bitcoin-bash-tools; prove;)
```
Description

This repository contains bitcoin-related bash functions, allowing bitcoin
private keys generation and processing from and to various formats.
To discourage the handling of keys in plain text, most of these functions
mainly read and print keys in binary. The base58check version is only read
or printed when reading from or writing to a terminal.

Base-58 encoding

base58 is a simple filter
implementing Satoshi Nakamoto’s binary-to-text encoding.
Its interface is inspired from coreutils’ base64.
```
$ openssl rand 20 |base58
2xkZS9xy8ViTSrJejTjgd2RpkZRn
```
With the -c option, the checksum is added.
```
$ echo foo |base58 -c
J8kY46kF5y6
```
With the -v option, the checksum is verified.
```
$ echo foo |base58   |base58 -v || echo wrong checksum
wrong checksum
$ echo foo |base58 -c|base58 -v && echo good checksum
good checksum
```
Decoding is done with the -d option.
```
$ base58 -d <<<J8kY46kF5y6
foo
M-MDjM-^E
```
As seen above, when writing to a terminal, base58 will escape non-printable characters.
Input can be coming from a file when giving the filename
(or say a process substitution)
as positional parameter :
```
$ base58 <(echo foo)
3csAed
```
A large file will take a very long time to process though, as this encoding is absolutely not
optimized to deal with large data.

Bech32

Bech32 is a string format used to encode
segwit addresses, but by
itself it is not a binary-to-text encoding, as it needs additional conventions
for padding.
Therefore, the bech32 function in this library does not read binary data, but
merely creates a Bech32 string from a human readable part and a non checked data
part :
```
$ bech32 this-part-is-readable-by-a-human qpzry
this-part-is-readable-by-a-human1qpzrylhvwcq
```
The -m option creates a
bech32m
string :
```
$ bech32 -m this-part-is-readable-by-a-human qpzry
this-part-is-readable-by-a-human1qpzry2tuzaz
```
The -v option can be used to verify the checksum :
```
$ bech32 -v this-part-is-readable-by-a-human1qpzrylhvwcq && echo good checksum
good checksum

$ bech32 -m -v this-part-is-readable-by-a-human1qpzry2tuzaz && echo good checksum
good checksum
```
Wallet Import Format

The function wif reads 32 bytes from stdin,
interprets them as a secp256k1 exponent
and displays the corresponding private key in Wallet Import
Format.
```
$ openssl rand 32 |wif
L1zAdArjAUgbDKj8LYxs5NsFk5JB7dTKGLCNMNQXyzE4tWZBGqs9
```
With the -u option, the uncompressed version is returned.
With the -t option, the testnet
version is returned.
With the -d option, the reverse operation is performed : reading a
key in WIF from stdin and printing 32 bytes to non-terminal standard output.
When writing to a terminal, the output is in a format used by
openssl ec.

Extended keys

Generation and derivation of eXtended keys, as described in
BIP-0032 and its successors BIP-0044,
BIP-0049 and BIP-0084, are supported by three filters, namely bip32, bip49 and bip84,
along with three respective aliases xkey, ykey and zkey.
The aliases exist for the sole reason that they are arguably easier to type.
Unless the option -p, -s or -t is used, these functions read 78 bytes
from stdin and interpret these as a serialized extended key. Then the
extended key derived according to a derivation path provided as a positional
parameter is computed and printed on stdout.
A base58check-encoded key can be passed as input if it is pasted
in the terminal, but to pass it through a pipe, it must first be decoded with
base58 -d:
```
$ myxprvkey=xprv9s21ZrQH143K31xYSDQpPDxsXRTUcvj2iNHm5NUtrGiGG5e2DtALGdso3pGz6ssrdK4PFmM8NSpSBHNqPqm55Qn3LqFtT2emdEXVYsCzC2U
$ base58 -d <<<"$myxprvkey" |xkey /0
xprv9vHkqa6EV4sPZHYqZznhT2NPtPCjKuDKGY38FBWLvgaDx45zo9WQRUT3dKYnjwih2yJD9mkrocEZXo1ex8G81dwSM1fwqWpWkeS3v86pgKt
```
To capture the base58check-encoded result, encoding must be performed explicitely with base58 -c.
```
$ myXkey="$(base58 -d <<<"$myxprvkey"| xkey /0 |base58 -c)"
```
When the -s option is used, stdin is used as a binary seed instead
of an extended key. This option is thus required to generate a master key :
```
$ openssl rand 64 |tee myseed |xkey -s
xprv9s21ZrQHREDACTEDtahEqxcVoeTTAS5dMAqREDACTEDDZd7Av8eHm6cWFRLz5P5C6YporfPgTxC6rREDACTEDn5kJBuQY1v4ZVejoHFQxUg
```
Any key in the key tree can be generated from a seed, though:
```
$ cat myseed |xkey -s m/0h/0/0
```
When the -t option is used, stdin is used as a binary seed and the generated
key will be a testnet key.
```
$ cat myseed |xkey -t
tprv8ZgxMBicQKsPen8dPzk2REDACTEDiRWqeNcdvrrxLsJ7UZCB3wH5tQsUbCBEPDREDACTEDfTh3skpif3GFENREDACTEDgemFAhG914qE5EC
```
N is the derivation operator used to get the so-called neutered key, a.k.a the public extended key.
```
$ base58 -d <<<"$myxprvkey" |xkey /N
xpub661MyMwAqRbcFW31YEwpkMuc5THy2PSt5bDMsktWQcFF8syAmRUapSCGu8ED9W6oDMSgv6Zz8idoc4a6mr8BDzTJY47LJhkJ8UB7WEGuduB
```
ykey and zkey differ from xkey mostly by their serialization format, as described in bip-0049 and bip-0084.
```
$ openssl rand 64 > myseed
$ ykey -s < myseed
yprvABrGsX5C9jantX14t9AjGYHoPw5LV3wdRD9JH3UxsEkMsxv3BcdzSFnqNidrmQ82nnLCmu3w6PWMZjPTmLKSAdBFBnXhqoE3VgBQLN6xJzg
$ zkey -s < myseed
zprvAWgYBBk7JR8GjieqUJjUQTqxVwy22Z7ZMPTUXJf2tsHG5Wa83ez3TQFqWWNCTVfyEc3tk7PxY2KTytxCMvW4p7obDWvymgbk2AmoQq1qL8Q
```
You can feed any file to these functions, and such file doesn’t have to be 64 bytes long.
It should, however, contain at least that much entropy.
If the derivation path begins with m or M, and unless the option -p, -s or
-t is used, additional checks are performed to ensure that the input is a
master private key or a master public key respectively.
When reading a binary seed, under the hood the seed feeds the following openssl command :
```
openssl dgst -sha512 -hmac "Bitcoin seed" -binary
```
The output of this command is then split in two to produce a chain code and a private exponent,
as described in bip-0032.

Mnemonics

It is possible to store the keys of a hierarchical deterministic wallet in biological
memory using mnemonics methods. Bitcoin-bash-tools offers two methods for this purpose :
the first one is an implementation of the dedicated BIP, and the other is a method based on
long known mnemonics techniques.

Bip-39

A seed can be produced from a mnemonic, a.k.a a secret phrase, as described
in BIP-0039.
To create a mnemonic, a function create-mnemonic takes as argument an amount of entropy in bits
either 128, 160, 192, 224 or 256. Default is 160.
```
$ create-mnemonic 128
invest hedgehog slogan unfold liar thunder cream leaf kiss combine minor document
```
The function will attempt to read the locale
settings to figure out which language to use. If it fails, or if the local language is not
supported, it will use English.
To override local language settings, set the LANG environment variable :
```
$ LANG=zh_TW create-mnemonic
凍濾槍斷覆捉斷山未飛沿始瓦曰撐
```
As you can see, Chinese output does not use spaces.
Alternatively, the function can take as argument some noise in hexadecimal (the
corresponding number of bits must be a multiple of 32).
```
$ create-mnemonic "$(openssl rand -hex 20)"
poem season process confirm meadow hidden will direct seed void height shadow live visual sauce
```
To create a seed from a mnemonic, there is a function mnemonic-to-seed.
```
$...
```

Bitcoin bash tools

Table of contents

Synopsis

Description

Base-58 encoding

Bech32

Wallet Import Format

Extended keys

Mnemonics

Bip-39