sui_sdk_types/
digest.rs

1/// A 32-byte Blake2b256 hash output.
2///
3/// # BCS
4///
5/// A `Digest`'s BCS serialized form is defined by the following:
6///
7/// ```text
8/// digest = %x20 32OCTET
9/// ```
10///
11/// Due to historical reasons, even though a `Digest` has a fixed-length of 32, Sui's binary
12/// representation of a `Digest` is prefixed with its length meaning its serialized binary form (in
13/// bcs) is 33 bytes long vs a more compact 32 bytes.
14#[derive(Clone, Copy, Default, Hash, PartialEq, Eq, PartialOrd, Ord)]
15#[cfg_attr(
16    feature = "serde",
17    derive(serde_derive::Serialize, serde_derive::Deserialize)
18)]
19#[cfg_attr(feature = "proptest", derive(test_strategy::Arbitrary))]
20#[doc(alias = "CheckpointDigest")]
21#[doc(alias = "TransactionDigest")]
22pub struct Digest(
23    #[cfg_attr(feature = "serde", serde(with = "DigestSerialization"))] [u8; Self::LENGTH],
24);
25
26impl Digest {
27    /// A constant representing the length of a digest in bytes.
28    pub const LENGTH: usize = 32;
29    /// A constant representing a zero digest.
30    pub const ZERO: Self = Self([0; Self::LENGTH]);
31
32    /// Generates a new digest from the provided 32 byte array containing [`u8`] values.
33    pub const fn new(digest: [u8; Self::LENGTH]) -> Self {
34        Self(digest)
35    }
36
37    /// Generates a new digest from the provided random number generator.
38    #[cfg(feature = "rand")]
39    #[cfg_attr(doc_cfg, doc(cfg(feature = "rand")))]
40    pub fn generate<R>(mut rng: R) -> Self
41    where
42        R: rand_core::RngCore + rand_core::CryptoRng,
43    {
44        let mut buf: [u8; Self::LENGTH] = [0; Self::LENGTH];
45        rng.fill_bytes(&mut buf);
46        Self::new(buf)
47    }
48
49    /// Returns a slice to the inner array representation of this digest.
50    pub const fn inner(&self) -> &[u8; Self::LENGTH] {
51        &self.0
52    }
53
54    /// Returns the inner array representation of this digest.
55    pub const fn into_inner(self) -> [u8; Self::LENGTH] {
56        self.0
57    }
58
59    /// Returns a slice of bytes representing the digest.
60    pub const fn as_bytes(&self) -> &[u8] {
61        &self.0
62    }
63
64    /// Decodes a digest from a Base58 encoded string.
65    pub fn from_base58<T: AsRef<[u8]>>(base58: T) -> Result<Self, DigestParseError> {
66        let mut buf = [0; Self::LENGTH];
67
68        bs58::decode(base58)
69            .onto(&mut buf)
70            //TODO fix error to contain bs58 parse error
71            .map_err(|_| DigestParseError)?;
72
73        Ok(Self(buf))
74    }
75
76    /// Returns a Base58 encoded string representation of this digest.
77    pub fn to_base58(&self) -> String {
78        self.to_string()
79    }
80
81    /// Generates a digest from bytes.
82    pub fn from_bytes<T: AsRef<[u8]>>(bytes: T) -> Result<Self, DigestParseError> {
83        <[u8; Self::LENGTH]>::try_from(bytes.as_ref())
84            .map_err(|_| DigestParseError)
85            .map(Self)
86    }
87}
88
89impl std::str::FromStr for Digest {
90    type Err = DigestParseError;
91
92    fn from_str(s: &str) -> Result<Self, Self::Err> {
93        Self::from_base58(s)
94    }
95}
96
97impl AsRef<[u8]> for Digest {
98    fn as_ref(&self) -> &[u8] {
99        &self.0
100    }
101}
102
103impl AsRef<[u8; Self::LENGTH]> for Digest {
104    fn as_ref(&self) -> &[u8; Self::LENGTH] {
105        &self.0
106    }
107}
108
109impl From<Digest> for [u8; Digest::LENGTH] {
110    fn from(digest: Digest) -> Self {
111        digest.into_inner()
112    }
113}
114
115impl From<[u8; Self::LENGTH]> for Digest {
116    fn from(digest: [u8; Self::LENGTH]) -> Self {
117        Self::new(digest)
118    }
119}
120
121impl std::fmt::Display for Digest {
122    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
123        // output size is determined via the following formula:
124        //      N * log(256) / log(58) + 1 (round up)
125        // where N = 32 this results in a value of 45
126        let mut buf = [0; 45];
127
128        let len = bs58::encode(&self.0).onto(&mut buf[..]).unwrap();
129        let encoded = std::str::from_utf8(&buf[..len]).unwrap();
130
131        f.write_str(encoded)
132    }
133}
134
135impl std::fmt::Debug for Digest {
136    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
137        f.debug_tuple("Digest")
138            .field(&format_args!("\"{self}\""))
139            .finish()
140    }
141}
142
143impl std::fmt::LowerHex for Digest {
144    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
145        if f.alternate() {
146            write!(f, "0x")?;
147        }
148
149        for byte in self.0 {
150            write!(f, "{byte:02x}")?;
151        }
152
153        Ok(())
154    }
155}
156
157// Unfortunately sui's binary representation of digests is prefixed with its length meaning its
158// serialized binary form is 33 bytes long (in bcs) vs a more compact 32 bytes.
159#[cfg(feature = "serde")]
160type DigestSerialization =
161    ::serde_with::As<::serde_with::IfIsHumanReadable<ReadableDigest, ::serde_with::Bytes>>;
162
163#[cfg(feature = "serde")]
164#[cfg_attr(doc_cfg, doc(cfg(feature = "serde")))]
165struct ReadableDigest;
166
167#[cfg(feature = "serde")]
168#[cfg_attr(doc_cfg, doc(cfg(feature = "serde")))]
169impl serde_with::SerializeAs<[u8; Digest::LENGTH]> for ReadableDigest {
170    fn serialize_as<S>(source: &[u8; Digest::LENGTH], serializer: S) -> Result<S::Ok, S::Error>
171    where
172        S: serde::Serializer,
173    {
174        let digest = Digest::new(*source);
175        serde_with::DisplayFromStr::serialize_as(&digest, serializer)
176    }
177}
178
179#[cfg(feature = "serde")]
180#[cfg_attr(doc_cfg, doc(cfg(feature = "serde")))]
181impl<'de> serde_with::DeserializeAs<'de, [u8; Digest::LENGTH]> for ReadableDigest {
182    fn deserialize_as<D>(deserializer: D) -> Result<[u8; Digest::LENGTH], D::Error>
183    where
184        D: serde::Deserializer<'de>,
185    {
186        let digest: Digest = serde_with::DisplayFromStr::deserialize_as(deserializer)?;
187        Ok(digest.into_inner())
188    }
189}
190
191#[derive(Clone, Copy, Debug, PartialEq, Eq)]
192pub struct DigestParseError;
193
194impl std::fmt::Display for DigestParseError {
195    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
196        write!(
197            f,
198            "Unable to parse Digest (must be Base58 string of length {})",
199            Digest::LENGTH
200        )
201    }
202}
203
204impl std::error::Error for DigestParseError {}
205
206// Don't implement like the other digest types since this isn't intended to be serialized
207pub type SigningDigest = [u8; Digest::LENGTH];
208
209#[cfg(test)]
210mod test {
211    use super::*;
212    use test_strategy::proptest;
213
214    #[cfg(target_arch = "wasm32")]
215    use wasm_bindgen_test::wasm_bindgen_test as test;
216
217    #[proptest]
218    fn roundtrip_display_fromstr(digest: Digest) {
219        let s = digest.to_string();
220        let d = s.parse::<Digest>().unwrap();
221        assert_eq!(digest, d);
222    }
223}
sui_sdk_types/digest.rs

sui_sdk_types/
digest.rs
