miden_protocol/note/
recipient.rs

1use core::fmt::Debug;
2
3use super::{
4    ByteReader,
5    ByteWriter,
6    Deserializable,
7    DeserializationError,
8    Hasher,
9    NoteScript,
10    NoteStorage,
11    Serializable,
12    Word,
13};
14
15/// Value that describes under which condition a note can be consumed.
16///
17/// The recipient is not an account address, instead it is a value that describes when a note
18/// can be consumed. Because not all notes have predetermined consumer addresses, e.g. swap
19/// notes can be consumed by anyone, the recipient is defined as the code and its storage, that
20/// when successfully executed results in the note's consumption.
21///
22/// Recipient is computed as:
23///
24/// > hash(hash(hash(serial_num, [0; 4]), script_root), storage_commitment)
25#[derive(Clone, Debug, PartialEq, Eq)]
26pub struct NoteRecipient {
27    serial_num: Word,
28    script: NoteScript,
29    storage: NoteStorage,
30    digest: Word,
31}
32
33impl NoteRecipient {
34    pub fn new(serial_num: Word, script: NoteScript, storage: NoteStorage) -> Self {
35        let digest = compute_recipient_digest(serial_num, &script, &storage);
36        Self { serial_num, script, storage, digest }
37    }
38
39    // PUBLIC ACCESSORS
40    // --------------------------------------------------------------------------------------------
41
42    /// The recipient's serial_num, the secret required to consume the note.
43    pub fn serial_num(&self) -> Word {
44        self.serial_num
45    }
46
47    /// The recipients's script which locks the assets of this note.
48    pub fn script(&self) -> &NoteScript {
49        &self.script
50    }
51
52    /// The recipient's storage which customizes the script's behavior.
53    pub fn storage(&self) -> &NoteStorage {
54        &self.storage
55    }
56
57    /// The recipient's digest, which commits to its details.
58    ///
59    /// This is the public data required to create a note.
60    pub fn digest(&self) -> Word {
61        self.digest
62    }
63
64    // MUTATORS
65    // --------------------------------------------------------------------------------------------
66
67    /// Reduces the size of the note script by stripping all debug info from it.
68    pub fn minify_script(&mut self) {
69        self.script.clear_debug_info();
70    }
71
72    /// Consumes self and returns the underlying parts of the [`NoteRecipient`].
73    pub fn into_parts(self) -> (Word, NoteScript, NoteStorage) {
74        (self.serial_num, self.script, self.storage)
75    }
76}
77
78fn compute_recipient_digest(serial_num: Word, script: &NoteScript, storage: &NoteStorage) -> Word {
79    let serial_num_hash = Hasher::merge(&[serial_num, Word::empty()]);
80    let merge_script = Hasher::merge(&[serial_num_hash, script.root()]);
81    Hasher::merge(&[merge_script, storage.commitment()])
82}
83
84// SERIALIZATION
85// ================================================================================================
86
87impl Serializable for NoteRecipient {
88    fn write_into<W: ByteWriter>(&self, target: &mut W) {
89        let Self {
90            script,
91            storage,
92            serial_num,
93
94            // These attributes don't have to be serialized, they can be re-computed from the rest
95            // of the data
96            digest: _,
97        } = self;
98
99        script.write_into(target);
100        storage.write_into(target);
101        serial_num.write_into(target);
102    }
103
104    fn get_size_hint(&self) -> usize {
105        self.script.get_size_hint() + self.storage.get_size_hint() + Word::SERIALIZED_SIZE
106    }
107}
108
109impl Deserializable for NoteRecipient {
110    fn read_from<R: ByteReader>(source: &mut R) -> Result<Self, DeserializationError> {
111        let script = NoteScript::read_from(source)?;
112        let storage = NoteStorage::read_from(source)?;
113        let serial_num = Word::read_from(source)?;
114
115        Ok(Self::new(serial_num, script, storage))
116    }
117}
miden_protocol/note/recipient.rs

miden_protocol/note/
recipient.rs
