// Rust Bitcoin Library
// Written by
// The Rust Bitcoin developers
//
// To the extent possible under law, the author(s) have dedicated all
// copyright and related and neighboring rights to this software to
// the public domain worldwide. This software is distributed without
// any warranty.
//
// You should have received a copy of the CC0 Public Domain Dedication
// along with this software.
// If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
//
use std::collections::BTreeMap;
use std::collections::btree_map::Entry;
use std::io::{self, Cursor, Read};
use std::cmp;
use blockdata::transaction::Transaction;
use consensus::{encode, Encodable, Decodable};
use util::psbt::map::Map;
use util::psbt::raw;
use util::psbt;
use util::psbt::Error;
use util::endian::u32_to_array_le;
use util::bip32::{ExtendedPubKey, KeySource, Fingerprint, DerivationPath, ChildNumber};
/// Type: Unsigned Transaction PSBT_GLOBAL_UNSIGNED_TX = 0x00
const PSBT_GLOBAL_UNSIGNED_TX: u8 = 0x00;
/// Type: Extended Public Key PSBT_GLOBAL_XPUB = 0x01
const PSBT_GLOBAL_XPUB: u8 = 0x01;
/// Type: Version Number PSBT_GLOBAL_VERSION = 0xFB
const PSBT_GLOBAL_VERSION: u8 = 0xFB;
/// Type: Proprietary Use Type PSBT_GLOBAL_PROPRIETARY = 0xFC
const PSBT_GLOBAL_PROPRIETARY: u8 = 0xFC;
/// A key-value map for global data.
#[derive(Clone, Debug, PartialEq)]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
pub struct Global {
/// The unsigned transaction, scriptSigs and witnesses for each input must be
/// empty.
pub unsigned_tx: Transaction,
/// The version number of this PSBT. If omitted, the version number is 0.
pub version: u32,
/// A global map from extended public keys to the used key fingerprint and
/// derivation path as defined by BIP 32
pub xpub: BTreeMap<ExtendedPubKey, KeySource>,
/// Global proprietary key-value pairs.
pub proprietary: BTreeMap<raw::ProprietaryKey, Vec<u8>>,
/// Unknown global key-value pairs.
pub unknown: BTreeMap<raw::Key, Vec<u8>>,
}
impl Global {
/// Create a Global from an unsigned transaction, error if not unsigned
pub fn from_unsigned_tx(tx: Transaction) -> Result<Self, psbt::Error> {
for txin in &tx.input {
if !txin.script_sig.is_empty() {
return Err(Error::UnsignedTxHasScriptSigs);
}
if !txin.witness.is_empty() {
return Err(Error::UnsignedTxHasScriptWitnesses);
}
}
Ok(Global {
unsigned_tx: tx,
xpub: Default::default(),
version: 0,
proprietary: Default::default(),
unknown: Default::default(),
})
}
}
impl Map for Global {
fn insert_pair(&mut self, pair: raw::Pair) -> Result<(), encode::Error> {
let raw::Pair {
key: raw_key,
value: raw_value,
} = pair;
match raw_key.type_value {
PSBT_GLOBAL_UNSIGNED_TX => return Err(Error::DuplicateKey(raw_key).into()),
PSBT_GLOBAL_PROPRIETARY => match self.proprietary.entry(raw::ProprietaryKey::from_key(raw_key.clone())?) {
Entry::Vacant(empty_key) => {empty_key.insert(raw_value);},
Entry::Occupied(_) => return Err(Error::DuplicateKey(raw_key).into()),
}
_ => match self.unknown.entry(raw_key) {
Entry::Vacant(empty_key) => {empty_key.insert(raw_value);},
Entry::Occupied(k) => return Err(Error::DuplicateKey(k.key().clone()).into()),
}
}
Ok(())
}
fn get_pairs(&self) -> Result<Vec<raw::Pair>, encode::Error> {
let mut rv: Vec<raw::Pair> = Default::default();
rv.push(raw::Pair {
key: raw::Key {
type_value: PSBT_GLOBAL_UNSIGNED_TX,
key: vec![],
},
value: {
// Manually serialized to ensure 0-input txs are serialized
// without witnesses.
let mut ret = Vec::new();
self.unsigned_tx.version.consensus_encode(&mut ret)?;
self.unsigned_tx.input.consensus_encode(&mut ret)?;
self.unsigned_tx.output.consensus_encode(&mut ret)?;
self.unsigned_tx.lock_time.consensus_encode(&mut ret)?;
ret
},
});
for (xpub, (fingerprint, derivation)) in &self.xpub {
rv.push(raw::Pair {
key: raw::Key {
type_value: PSBT_GLOBAL_XPUB,
key: xpub.encode().to_vec(),
},
value: {
let mut ret = Vec::with_capacity(4 + derivation.len() * 4);
ret.extend(fingerprint.as_bytes());
derivation.into_iter().for_each(|n| ret.extend(&u32_to_array_le((*n).into())));
ret
}
});
}
// Serializing version only for non-default value; otherwise test vectors fail
if self.version > 0 {
rv.push(raw::Pair {
key: raw::Key {
type_value: PSBT_GLOBAL_VERSION,
key: vec![],
},
value: u32_to_array_le(self.version).to_vec()
});
}
for (key, value) in self.proprietary.iter() {
rv.push(raw::Pair {
key: key.to_key(),
value: value.clone(),
});
}
for (key, value) in self.unknown.iter() {
rv.push(raw::Pair {
key: key.clone(),
value: value.clone(),
});
}
Ok(rv)
}
// Keep in mind that according to BIP 174 this function must be commutative, i.e.
// A.merge(B) == B.merge(A)
fn merge(&mut self, other: Self) -> Result<(), psbt::Error> {
if self.unsigned_tx != other.unsigned_tx {
return Err(psbt::Error::UnexpectedUnsignedTx {
expected: self.unsigned_tx.clone(),
actual: other.unsigned_tx,
});
}
// BIP 174: The Combiner must remove any duplicate key-value pairs, in accordance with
// the specification. It can pick arbitrarily when conflicts occur.
// Keeping the highest version
self.version = cmp::max(self.version, other.version);
// Merging xpubs
for (xpub, (fingerprint1, derivation1)) in other.xpub {
match self.xpub.entry(xpub) {
Entry::Vacant(entry) => {
entry.insert((fingerprint1, derivation1));
},
Entry::Occupied(mut entry) => {
// Here in case of the conflict we select the version with algorithm:
// 1) if everything is equal we do nothing
// 2) report an error if
// - derivation paths are equal and fingerprints are not
// - derivation paths are of the same length, but not equal
// - derivation paths has different length, but the shorter one
// is not the strict suffix of the longer one
// 3) choose longest derivation otherwise
let (fingerprint2, derivation2) = entry.get().clone();
if derivation1 == derivation2 && fingerprint1 == fingerprint2
{
continue
}
else if
derivation1.len() < derivation2.len() &&
derivation1[..] == derivation2[derivation2.len() - derivation1.len()..]
{
continue
}
else if derivation2[..] == derivation1[derivation1.len() - derivation2.len()..]
{
entry.insert((fingerprint1, derivation1));
continue
}
return Err(psbt::Error::MergeConflict(format!(
"global xpub {} has inconsistent key sources", xpub
).to_owned()));
}
}
}
self.proprietary.extend(other.proprietary);
self.unknown.extend(other.unknown);
Ok(())
}
}
impl_psbtmap_consensus_encoding!(Global);
impl Decodable for Global {
fn consensus_decode<D: io::Read>(mut d: D) -> Result<Self, encode::Error> {
let mut tx: Option<Transaction> = None;
let mut version: Option<u32> = None;
let mut unknowns: BTreeMap<raw::Key, Vec<u8>> = Default::default();
let mut xpub_map: BTreeMap<ExtendedPubKey, (Fingerprint, DerivationPath)> = Default::default();
let mut proprietary: BTreeMap<raw::ProprietaryKey, Vec<u8>> = Default::default();
loop {
match raw::Pair::consensus_decode(&mut d) {
Ok(pair) => {
match pair.key.type_value {
PSBT_GLOBAL_UNSIGNED_TX => {
// key has to be empty
if pair.key.key.is_empty() {
// there can only be one unsigned transaction
if tx.is_none() {
let vlen: usize = pair.value.len();
let mut decoder = Cursor::new(pair.value);
// Manually deserialized to ensure 0-input
// txs without witnesses are deserialized
// properly.
tx = Some(Transaction {
version: Decodable::consensus_decode(&mut decoder)?,
input: Decodable::consensus_decode(&mut decoder)?,
output: Decodable::consensus_decode(&mut decoder)?,
lock_time: Decodable::consensus_decode(&mut decoder)?,
});
if decoder.position() != vlen as u64 {
return Err(encode::Error::ParseFailed("data not consumed entirely when explicitly deserializing"))
}
} else {
return Err(Error::DuplicateKey(pair.key).into())
}
} else {
return Err(Error::InvalidKey(pair.key).into())
}
}
PSBT_GLOBAL_XPUB => {
if !pair.key.key.is_empty() {
let xpub = ExtendedPubKey::decode(&pair.key.key)
.map_err(|_| encode::Error::ParseFailed(
"Can't deserialize ExtendedPublicKey from global XPUB key data"
))?;
if pair.value.is_empty() || pair.value.len() % 4 != 0 {
return Err(encode::Error::ParseFailed("Incorrect length of global xpub derivation data"))
}
let child_count = pair.value.len() / 4 - 1;
let mut decoder = Cursor::new(pair.value);
let mut fingerprint = [0u8; 4];
decoder.read_exact(&mut fingerprint[..])?;
let mut path = Vec::<ChildNumber>::with_capacity(child_count);
while let Ok(index) = u32::consensus_decode(&mut decoder) {
path.push(ChildNumber::from(index))
}
let derivation = DerivationPath::from(path);
// Keys, according to BIP-174, must be unique
if xpub_map.insert(xpub, (Fingerprint::from(&fingerprint[..]), derivation)).is_some() {
return Err(encode::Error::ParseFailed("Repeated global xpub key"))
}
} else {
return Err(encode::Error::ParseFailed("Xpub global key must contain serialized Xpub data"))
}
}
PSBT_GLOBAL_VERSION => {
// key has to be empty
if pair.key.key.is_empty() {
// there can only be one version
if version.is_none() {
let vlen: usize = pair.value.len();
let mut decoder = Cursor::new(pair.value);
if vlen != 4 {
return Err(encode::Error::ParseFailed("Wrong global version value length (must be 4 bytes)"))
}
version = Some(Decodable::consensus_decode(&mut decoder)?);
// We only understand version 0 PSBTs. According to BIP-174 we
// should throw an error if we see anything other than version 0.
if version != Some(0) {
return Err(encode::Error::ParseFailed("PSBT versions greater than 0 are not supported"))
}
} else {
return Err(Error::DuplicateKey(pair.key).into())
}
} else {
return Err(Error::InvalidKey(pair.key).into())
}
}
PSBT_GLOBAL_PROPRIETARY => match proprietary.entry(raw::ProprietaryKey::from_key(pair.key.clone())?) {
Entry::Vacant(empty_key) => {empty_key.insert(pair.value);},
Entry::Occupied(_) => return Err(Error::DuplicateKey(pair.key).into()),
}
_ => match unknowns.entry(pair.key) {
Entry::Vacant(empty_key) => {empty_key.insert(pair.value);},
Entry::Occupied(k) => return Err(Error::DuplicateKey(k.key().clone()).into()),
}
}
}
Err(::consensus::encode::Error::Psbt(::util::psbt::Error::NoMorePairs)) => break,
Err(e) => return Err(e),
}
}
if let Some(tx) = tx {
let mut rv: Global = Global::from_unsigned_tx(tx)?;
rv.version = version.unwrap_or(0);
rv.xpub = xpub_map;
rv.unknown = unknowns;
Ok(rv)
} else {
Err(Error::MustHaveUnsignedTx.into())
}
}
}