zebra_chain/transparent.rs
1//! Transparent-related (Bitcoin-inherited) functionality.
2
3mod address;
4mod keys;
5mod opcodes;
6mod script;
7mod serialize;
8mod utxo;
9
10use std::{collections::HashMap, fmt, iter};
11
12pub use address::Address;
13use zcash_transparent::{address::TransparentAddress, bundle::TxOut};
14
15use crate::{
16 amount::{Amount, NonNegative},
17 block,
18 parameters::Network,
19 transaction,
20};
21
22pub use script::Script;
23pub use serialize::{GENESIS_COINBASE_DATA, MAX_COINBASE_DATA_LEN, MAX_COINBASE_HEIGHT_DATA_LEN};
24pub use utxo::{
25 new_ordered_outputs, new_outputs, outputs_from_utxos, utxos_from_ordered_utxos,
26 CoinbaseSpendRestriction, OrderedUtxo, Utxo,
27};
28
29#[cfg(any(test, feature = "proptest-impl"))]
30pub use utxo::{
31 new_ordered_outputs_with_height, new_outputs_with_height, new_transaction_ordered_outputs,
32};
33
34#[cfg(any(test, feature = "proptest-impl"))]
35mod arbitrary;
36
37#[cfg(test)]
38mod tests;
39
40#[cfg(any(test, feature = "proptest-impl"))]
41use proptest_derive::Arbitrary;
42
43/// The maturity threshold for transparent coinbase outputs.
44///
45/// "A transaction MUST NOT spend a transparent output of a coinbase transaction
46/// from a block less than 100 blocks prior to the spend. Note that transparent
47/// outputs of coinbase transactions include Founders' Reward outputs and
48/// transparent Funding Stream outputs."
49/// [7.1](https://zips.z.cash/protocol/nu5.pdf#txnencodingandconsensus)
50//
51// TODO: change type to HeightDiff
52pub const MIN_TRANSPARENT_COINBASE_MATURITY: u32 = 100;
53
54/// Extra coinbase data that identifies some coinbase transactions generated by Zebra.
55/// <https://emojipedia.org/zebra/>
56//
57// # Note
58//
59// rust-analyzer will crash in some editors when moving over an actual Zebra emoji,
60// so we encode it here. This is a known issue in emacs-lsp and other lsp implementations:
61// - https://github.com/rust-lang/rust-analyzer/issues/9121
62// - https://github.com/emacs-lsp/lsp-mode/issues/2080
63// - https://github.com/rust-lang/rust-analyzer/issues/13709
64pub const EXTRA_ZEBRA_COINBASE_DATA: &str = "z\u{1F993}";
65
66/// Arbitrary data inserted by miners into a coinbase transaction.
67//
68// TODO: rename to ExtraCoinbaseData, because height is also part of the coinbase data?
69#[derive(Clone, Eq, PartialEq)]
70#[cfg_attr(
71 any(test, feature = "proptest-impl", feature = "elasticsearch"),
72 derive(Serialize)
73)]
74pub struct CoinbaseData(
75 /// Invariant: this vec, together with the coinbase height, must be less than
76 /// 100 bytes. We enforce this by only constructing CoinbaseData fields by
77 /// parsing blocks with 100-byte data fields, and checking newly created
78 /// CoinbaseData lengths in the transaction builder.
79 pub(super) Vec<u8>,
80);
81
82#[cfg(any(test, feature = "proptest-impl"))]
83impl CoinbaseData {
84 /// Create a new `CoinbaseData` containing `data`.
85 ///
86 /// Only for use in tests.
87 pub fn new(data: Vec<u8>) -> CoinbaseData {
88 CoinbaseData(data)
89 }
90}
91
92impl AsRef<[u8]> for CoinbaseData {
93 fn as_ref(&self) -> &[u8] {
94 self.0.as_ref()
95 }
96}
97
98impl std::fmt::Debug for CoinbaseData {
99 #[allow(clippy::unwrap_in_result)]
100 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
101 let escaped = String::from_utf8(
102 self.0
103 .iter()
104 .cloned()
105 .flat_map(std::ascii::escape_default)
106 .collect(),
107 )
108 .expect("ascii::escape_default produces utf8");
109 f.debug_tuple("CoinbaseData").field(&escaped).finish()
110 }
111}
112
113/// OutPoint
114///
115/// A particular transaction output reference.
116#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
117#[cfg_attr(any(test, feature = "proptest-impl"), derive(Arbitrary))]
118#[cfg_attr(
119 any(test, feature = "proptest-impl", feature = "elasticsearch"),
120 derive(Serialize)
121)]
122pub struct OutPoint {
123 /// References the transaction that contains the UTXO being spent.
124 ///
125 /// # Correctness
126 ///
127 /// Consensus-critical serialization uses
128 /// [`ZcashSerialize`](crate::serialization::ZcashSerialize).
129 /// [`serde`]-based hex serialization must only be used for testing.
130 #[cfg_attr(any(test, feature = "proptest-impl"), serde(with = "hex"))]
131 pub hash: transaction::Hash,
132
133 /// Identifies which UTXO from that transaction is referenced; the
134 /// first output is 0, etc.
135 pub index: u32,
136}
137
138impl OutPoint {
139 /// Returns a new [`OutPoint`] from an in-memory output `index`.
140 ///
141 /// # Panics
142 ///
143 /// If `index` doesn't fit in a [`u32`].
144 pub fn from_usize(hash: transaction::Hash, index: usize) -> OutPoint {
145 OutPoint {
146 hash,
147 index: index
148 .try_into()
149 .expect("valid in-memory output indexes fit in a u32"),
150 }
151 }
152}
153
154/// A transparent input to a transaction.
155#[derive(Clone, Debug, Eq, PartialEq)]
156#[cfg_attr(
157 any(test, feature = "proptest-impl", feature = "elasticsearch"),
158 derive(Serialize)
159)]
160pub enum Input {
161 /// A reference to an output of a previous transaction.
162 PrevOut {
163 /// The previous output transaction reference.
164 outpoint: OutPoint,
165 /// The script that authorizes spending `outpoint`.
166 unlock_script: Script,
167 /// The sequence number for the output.
168 sequence: u32,
169 },
170 /// New coins created by the block reward.
171 Coinbase {
172 /// The height of this block.
173 height: block::Height,
174 /// Free data inserted by miners after the block height.
175 data: CoinbaseData,
176 /// The sequence number for the output.
177 sequence: u32,
178 },
179}
180
181impl fmt::Display for Input {
182 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
183 match self {
184 Input::PrevOut {
185 outpoint,
186 unlock_script,
187 ..
188 } => {
189 let mut fmter = f.debug_struct("transparent::Input::PrevOut");
190
191 fmter.field("unlock_script_len", &unlock_script.as_raw_bytes().len());
192 fmter.field("outpoint", outpoint);
193
194 fmter.finish()
195 }
196 Input::Coinbase { height, data, .. } => {
197 let mut fmter = f.debug_struct("transparent::Input::Coinbase");
198
199 fmter.field("height", height);
200 fmter.field("data_len", &data.0.len());
201
202 fmter.finish()
203 }
204 }
205 }
206}
207
208impl Input {
209 /// Returns a new coinbase input for `height` with optional `data` and `sequence`.
210 ///
211 /// # Consensus
212 ///
213 /// The combined serialized size of `height` and `data` can be at most 100 bytes.
214 ///
215 /// > A coinbase transaction script MUST have length in {2 .. 100} bytes.
216 ///
217 /// <https://zips.z.cash/protocol/protocol.pdf#txnconsensus>
218 ///
219 /// # Panics
220 ///
221 /// If the coinbase data is greater than [`MAX_COINBASE_DATA_LEN`].
222 pub fn new_coinbase(
223 height: block::Height,
224 data: Option<Vec<u8>>,
225 sequence: Option<u32>,
226 ) -> Input {
227 // "No extra coinbase data" is the default.
228 let data = data.unwrap_or_default();
229 let height_size = height.coinbase_zcash_serialized_size();
230
231 assert!(
232 data.len() + height_size <= MAX_COINBASE_DATA_LEN,
233 "invalid coinbase data: extra data {} bytes + height {height_size} bytes \
234 must be {} or less",
235 data.len(),
236 MAX_COINBASE_DATA_LEN,
237 );
238
239 Input::Coinbase {
240 height,
241 data: CoinbaseData(data),
242
243 // If the caller does not specify the sequence number,
244 // use a sequence number that activates the LockTime.
245 sequence: sequence.unwrap_or(0),
246 }
247 }
248
249 /// Returns the extra coinbase data in this input, if it is an [`Input::Coinbase`].
250 pub fn extra_coinbase_data(&self) -> Option<&CoinbaseData> {
251 match self {
252 Input::PrevOut { .. } => None,
253 Input::Coinbase { data, .. } => Some(data),
254 }
255 }
256
257 /// Returns the full coinbase script (the encoded height along with the
258 /// extra data) if this is an [`Input::Coinbase`]. Also returns `None` if
259 /// the coinbase is for the genesis block but does not match the expected
260 /// genesis coinbase data.
261 pub fn coinbase_script(&self) -> Option<Vec<u8>> {
262 match self {
263 Input::PrevOut { .. } => None,
264 Input::Coinbase { height, data, .. } => {
265 let mut height_and_data = Vec::new();
266 serialize::write_coinbase_height(*height, data, &mut height_and_data).ok()?;
267 height_and_data.extend(&data.0);
268 Some(height_and_data)
269 }
270 }
271 }
272
273 /// Returns the input's sequence number.
274 pub fn sequence(&self) -> u32 {
275 match self {
276 Input::PrevOut { sequence, .. } | Input::Coinbase { sequence, .. } => *sequence,
277 }
278 }
279
280 /// Sets the input's sequence number.
281 ///
282 /// Only for use in tests.
283 #[cfg(any(test, feature = "proptest-impl"))]
284 pub fn set_sequence(&mut self, new_sequence: u32) {
285 match self {
286 Input::PrevOut { sequence, .. } | Input::Coinbase { sequence, .. } => {
287 *sequence = new_sequence
288 }
289 }
290 }
291
292 /// If this is a [`Input::PrevOut`] input, returns this input's
293 /// [`OutPoint`]. Otherwise, returns `None`.
294 pub fn outpoint(&self) -> Option<OutPoint> {
295 if let Input::PrevOut { outpoint, .. } = self {
296 Some(*outpoint)
297 } else {
298 None
299 }
300 }
301
302 /// Set this input's [`OutPoint`].
303 ///
304 /// Should only be called on [`Input::PrevOut`] inputs.
305 ///
306 /// # Panics
307 ///
308 /// If `self` is a coinbase input.
309 #[cfg(any(test, feature = "proptest-impl"))]
310 pub fn set_outpoint(&mut self, new_outpoint: OutPoint) {
311 if let Input::PrevOut {
312 ref mut outpoint, ..
313 } = self
314 {
315 *outpoint = new_outpoint;
316 } else {
317 unreachable!("unexpected variant: Coinbase Inputs do not have OutPoints");
318 }
319 }
320
321 /// Get the value spent by this input, by looking up its [`OutPoint`] in `outputs`.
322 /// See [`Self::value`] for details.
323 ///
324 /// # Panics
325 ///
326 /// If the provided [`Output`]s don't have this input's [`OutPoint`].
327 pub(crate) fn value_from_outputs(
328 &self,
329 outputs: &HashMap<OutPoint, Output>,
330 ) -> Amount<NonNegative> {
331 match self {
332 Input::PrevOut { outpoint, .. } => {
333 outputs
334 .get(outpoint)
335 .unwrap_or_else(|| {
336 panic!(
337 "provided Outputs (length {:?}) don't have spent {:?}",
338 outputs.len(),
339 outpoint
340 )
341 })
342 .value
343 }
344 Input::Coinbase { .. } => Amount::zero(),
345 }
346 }
347
348 /// Get the value spent by this input, by looking up its [`OutPoint`] in
349 /// [`Utxo`]s.
350 ///
351 /// This amount is added to the transaction value pool by this input.
352 ///
353 /// # Panics
354 ///
355 /// If the provided [`Utxo`]s don't have this input's [`OutPoint`].
356 pub fn value(&self, utxos: &HashMap<OutPoint, utxo::Utxo>) -> Amount<NonNegative> {
357 if let Some(outpoint) = self.outpoint() {
358 // look up the specific Output and convert it to the expected format
359 let output = utxos
360 .get(&outpoint)
361 .expect("provided Utxos don't have spent OutPoint")
362 .output
363 .clone();
364 self.value_from_outputs(&iter::once((outpoint, output)).collect())
365 } else {
366 // coinbase inputs don't need any UTXOs
367 self.value_from_outputs(&HashMap::new())
368 }
369 }
370
371 /// Get the value spent by this input, by looking up its [`OutPoint`] in
372 /// [`OrderedUtxo`]s.
373 ///
374 /// See [`Self::value`] for details.
375 ///
376 /// # Panics
377 ///
378 /// If the provided [`OrderedUtxo`]s don't have this input's [`OutPoint`].
379 pub fn value_from_ordered_utxos(
380 &self,
381 ordered_utxos: &HashMap<OutPoint, utxo::OrderedUtxo>,
382 ) -> Amount<NonNegative> {
383 if let Some(outpoint) = self.outpoint() {
384 // look up the specific Output and convert it to the expected format
385 let output = ordered_utxos
386 .get(&outpoint)
387 .expect("provided Utxos don't have spent OutPoint")
388 .utxo
389 .output
390 .clone();
391 self.value_from_outputs(&iter::once((outpoint, output)).collect())
392 } else {
393 // coinbase inputs don't need any UTXOs
394 self.value_from_outputs(&HashMap::new())
395 }
396 }
397}
398
399/// A transparent output from a transaction.
400///
401/// The most fundamental building block of a transaction is a
402/// transaction output -- the ZEC you own in your "wallet" is in
403/// fact a subset of unspent transaction outputs (or "UTXO"s) of the
404/// global UTXO set.
405///
406/// UTXOs are indivisible, discrete units of value which can only be
407/// consumed in their entirety. Thus, if I want to send you 1 ZEC and
408/// I only own one UTXO worth 2 ZEC, I would construct a transaction
409/// that spends my UTXO and sends 1 ZEC to you and 1 ZEC back to me
410/// (just like receiving change).
411#[derive(Clone, Debug, Eq, PartialEq, Hash)]
412#[cfg_attr(any(test, feature = "proptest-impl"), derive(Arbitrary, Deserialize))]
413#[cfg_attr(
414 any(test, feature = "proptest-impl", feature = "elasticsearch"),
415 derive(Serialize)
416)]
417pub struct Output {
418 /// Transaction value.
419 // At https://en.bitcoin.it/wiki/Protocol_documentation#tx, this is an i64.
420 pub value: Amount<NonNegative>,
421
422 /// The lock script defines the conditions under which this output can be spent.
423 pub lock_script: Script,
424}
425
426impl Output {
427 /// Returns a new coinbase output that pays `amount` using `lock_script`.
428 pub fn new_coinbase(amount: Amount<NonNegative>, lock_script: Script) -> Output {
429 Output {
430 value: amount,
431 lock_script,
432 }
433 }
434
435 /// Get the value contained in this output.
436 /// This amount is subtracted from the transaction value pool by this output.
437 pub fn value(&self) -> Amount<NonNegative> {
438 self.value
439 }
440
441 /// Return the destination address from a transparent output.
442 ///
443 /// Returns None if the address type is not valid or unrecognized.
444 pub fn address(&self, net: &Network) -> Option<Address> {
445 match TxOut::try_from(self).ok()?.recipient_address()? {
446 TransparentAddress::PublicKeyHash(pkh) => {
447 Some(Address::from_pub_key_hash(net.t_addr_kind(), pkh))
448 }
449 TransparentAddress::ScriptHash(sh) => {
450 Some(Address::from_script_hash(net.t_addr_kind(), sh))
451 }
452 }
453 }
454}