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| 1 | +use core::fmt; |
| 2 | + |
| 3 | +use schemars::JsonSchema; |
| 4 | +use serde::{de, ser, Deserialize, Deserializer, Serialize}; |
| 5 | +use sha2::{Digest, Sha256}; |
| 6 | +use thiserror::Error; |
| 7 | + |
| 8 | +use crate::{StdError, StdResult}; |
| 9 | + |
| 10 | +/// A SHA-256 checksum of a Wasm blob, used to identify a Wasm code. |
| 11 | +/// This must remain stable since this checksum is stored in the blockchain state. |
| 12 | +/// |
| 13 | +/// This is often referred to as "code ID" in go-cosmwasm, even if code ID |
| 14 | +/// usually refers to an auto-incrementing number. |
| 15 | +#[derive(JsonSchema, Debug, Copy, Clone, PartialEq, Eq, Hash)] |
| 16 | +pub struct Checksum(#[schemars(with = "String")] [u8; 32]); |
| 17 | + |
| 18 | +impl Checksum { |
| 19 | + pub fn generate(wasm: &[u8]) -> Self { |
| 20 | + Checksum(Sha256::digest(wasm).into()) |
| 21 | + } |
| 22 | + |
| 23 | + /// Tries to parse the given hex string into a checksum. |
| 24 | + /// Errors if the string contains non-hex characters or does not contain 32 bytes. |
| 25 | + pub fn from_hex(input: &str) -> StdResult<Self> { |
| 26 | + let mut binary = [0u8; 32]; |
| 27 | + hex::decode_to_slice(input, &mut binary).map_err(StdError::invalid_hex)?; |
| 28 | + |
| 29 | + Ok(Self(binary)) |
| 30 | + } |
| 31 | + |
| 32 | + /// Creates a lowercase hex encoded copy of this checksum. |
| 33 | + /// |
| 34 | + /// This takes an owned `self` instead of a reference because `Checksum` is cheap to `Copy`. |
| 35 | + pub fn to_hex(self) -> String { |
| 36 | + self.to_string() |
| 37 | + } |
| 38 | + |
| 39 | + /// Returns a reference to the inner bytes of this checksum as a slice. |
| 40 | + /// If you need a reference to the array, use [`AsRef::as_ref`]. |
| 41 | + pub fn as_slice(&self) -> &[u8] { |
| 42 | + &self.0 |
| 43 | + } |
| 44 | +} |
| 45 | + |
| 46 | +impl fmt::Display for Checksum { |
| 47 | + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| 48 | + for byte in self.0.iter() { |
| 49 | + write!(f, "{byte:02x}")?; |
| 50 | + } |
| 51 | + Ok(()) |
| 52 | + } |
| 53 | +} |
| 54 | + |
| 55 | +impl From<[u8; 32]> for Checksum { |
| 56 | + fn from(data: [u8; 32]) -> Self { |
| 57 | + Checksum(data) |
| 58 | + } |
| 59 | +} |
| 60 | + |
| 61 | +impl AsRef<[u8; 32]> for Checksum { |
| 62 | + fn as_ref(&self) -> &[u8; 32] { |
| 63 | + &self.0 |
| 64 | + } |
| 65 | +} |
| 66 | + |
| 67 | +/// Serializes as a hex string |
| 68 | +impl Serialize for Checksum { |
| 69 | + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> |
| 70 | + where |
| 71 | + S: ser::Serializer, |
| 72 | + { |
| 73 | + serializer.serialize_str(&self.to_hex()) |
| 74 | + } |
| 75 | +} |
| 76 | + |
| 77 | +/// Deserializes as a hex string |
| 78 | +impl<'de> Deserialize<'de> for Checksum { |
| 79 | + fn deserialize<D>(deserializer: D) -> Result<Checksum, D::Error> |
| 80 | + where |
| 81 | + D: Deserializer<'de>, |
| 82 | + { |
| 83 | + deserializer.deserialize_str(ChecksumVisitor) |
| 84 | + } |
| 85 | +} |
| 86 | + |
| 87 | +struct ChecksumVisitor; |
| 88 | + |
| 89 | +impl<'de> de::Visitor<'de> for ChecksumVisitor { |
| 90 | + type Value = Checksum; |
| 91 | + |
| 92 | + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
| 93 | + formatter.write_str("valid hex encoded 32 byte checksum") |
| 94 | + } |
| 95 | + |
| 96 | + fn visit_str<E>(self, v: &str) -> Result<Self::Value, E> |
| 97 | + where |
| 98 | + E: de::Error, |
| 99 | + { |
| 100 | + match Checksum::from_hex(v) { |
| 101 | + Ok(data) => Ok(data), |
| 102 | + Err(_) => Err(E::custom(format!("invalid checksum: {v}"))), |
| 103 | + } |
| 104 | + } |
| 105 | +} |
| 106 | + |
| 107 | +#[derive(Error, Debug)] |
| 108 | +#[error("Checksum not of length 32")] |
| 109 | +pub struct ChecksumError; |
| 110 | + |
| 111 | +impl TryFrom<&[u8]> for Checksum { |
| 112 | + type Error = ChecksumError; |
| 113 | + |
| 114 | + fn try_from(value: &[u8]) -> Result<Self, Self::Error> { |
| 115 | + if value.len() != 32 { |
| 116 | + return Err(ChecksumError); |
| 117 | + } |
| 118 | + let mut data = [0u8; 32]; |
| 119 | + data.copy_from_slice(value); |
| 120 | + Ok(Checksum(data)) |
| 121 | + } |
| 122 | +} |
| 123 | + |
| 124 | +impl From<Checksum> for Vec<u8> { |
| 125 | + fn from(original: Checksum) -> Vec<u8> { |
| 126 | + original.0.into() |
| 127 | + } |
| 128 | +} |
| 129 | + |
| 130 | +#[cfg(test)] |
| 131 | +mod tests { |
| 132 | + use super::*; |
| 133 | + |
| 134 | + use crate::to_json_string; |
| 135 | + |
| 136 | + #[test] |
| 137 | + fn generate_works() { |
| 138 | + let wasm = vec![0x68, 0x69, 0x6a]; |
| 139 | + let checksum = Checksum::generate(&wasm); |
| 140 | + |
| 141 | + // echo -n "hij" | sha256sum |
| 142 | + let expected = [ |
| 143 | + 0x72, 0x2c, 0x8c, 0x99, 0x3f, 0xd7, 0x5a, 0x76, 0x27, 0xd6, 0x9e, 0xd9, 0x41, 0x34, |
| 144 | + 0x4f, 0xe2, 0xa1, 0x42, 0x3a, 0x3e, 0x75, 0xef, 0xd3, 0xe6, 0x77, 0x8a, 0x14, 0x28, |
| 145 | + 0x84, 0x22, 0x71, 0x04, |
| 146 | + ]; |
| 147 | + assert_eq!(checksum.0, expected); |
| 148 | + } |
| 149 | + |
| 150 | + #[test] |
| 151 | + fn implemented_display() { |
| 152 | + let wasm = vec![0x68, 0x69, 0x6a]; |
| 153 | + let checksum = Checksum::generate(&wasm); |
| 154 | + // echo -n "hij" | sha256sum |
| 155 | + let embedded = format!("Check: {checksum}"); |
| 156 | + assert_eq!( |
| 157 | + embedded, |
| 158 | + "Check: 722c8c993fd75a7627d69ed941344fe2a1423a3e75efd3e6778a142884227104" |
| 159 | + ); |
| 160 | + assert_eq!( |
| 161 | + checksum.to_string(), |
| 162 | + "722c8c993fd75a7627d69ed941344fe2a1423a3e75efd3e6778a142884227104" |
| 163 | + ); |
| 164 | + } |
| 165 | + |
| 166 | + #[test] |
| 167 | + fn from_hex_works() { |
| 168 | + // echo -n "hij" | sha256sum |
| 169 | + let checksum = "722c8c993fd75a7627d69ed941344fe2a1423a3e75efd3e6778a142884227104"; |
| 170 | + let parsed = Checksum::from_hex(checksum).unwrap(); |
| 171 | + assert_eq!(parsed, Checksum::generate(b"hij")); |
| 172 | + // should be inverse of `to_hex` |
| 173 | + assert_eq!(parsed.to_hex(), checksum); |
| 174 | + |
| 175 | + // invalid hex |
| 176 | + let too_short = "722c8c993fd75a7627d69ed941344fe2a1423a3e75efd3e6778a1428842271"; |
| 177 | + assert!(Checksum::from_hex(too_short).is_err()); |
| 178 | + let invalid_char = "722c8c993fd75a7627d69ed941344fe2a1423a3e75efd3e6778a1428842271g4"; |
| 179 | + assert!(Checksum::from_hex(invalid_char).is_err()); |
| 180 | + let too_long = "722c8c993fd75a7627d69ed941344fe2a1423a3e75efd3e6778a14288422710400"; |
| 181 | + assert!(Checksum::from_hex(too_long).is_err()); |
| 182 | + } |
| 183 | + |
| 184 | + #[test] |
| 185 | + fn to_hex_works() { |
| 186 | + let wasm = vec![0x68, 0x69, 0x6a]; |
| 187 | + let checksum = Checksum::generate(&wasm); |
| 188 | + // echo -n "hij" | sha256sum |
| 189 | + assert_eq!( |
| 190 | + checksum.to_hex(), |
| 191 | + "722c8c993fd75a7627d69ed941344fe2a1423a3e75efd3e6778a142884227104" |
| 192 | + ); |
| 193 | + } |
| 194 | + |
| 195 | + #[test] |
| 196 | + fn into_vec_works() { |
| 197 | + let checksum = Checksum::generate(&[12u8; 17]); |
| 198 | + let as_vec: Vec<u8> = checksum.into(); |
| 199 | + assert_eq!(as_vec, checksum.0); |
| 200 | + } |
| 201 | + |
| 202 | + #[test] |
| 203 | + fn ref_conversions_work() { |
| 204 | + let checksum = Checksum::generate(&[12u8; 17]); |
| 205 | + // as_ref |
| 206 | + let _: &[u8; 32] = checksum.as_ref(); |
| 207 | + let _: &[u8] = checksum.as_ref(); |
| 208 | + // as_slice |
| 209 | + let _: &[u8; 32] = checksum.as_ref(); |
| 210 | + let _: &[u8] = checksum.as_ref(); |
| 211 | + } |
| 212 | + |
| 213 | + #[test] |
| 214 | + fn serde_works() { |
| 215 | + // echo -n "hij" | sha256sum |
| 216 | + let checksum = |
| 217 | + Checksum::from_hex("722c8c993fd75a7627d69ed941344fe2a1423a3e75efd3e6778a142884227104") |
| 218 | + .unwrap(); |
| 219 | + |
| 220 | + let serialized = to_json_string(&checksum).unwrap(); |
| 221 | + assert_eq!( |
| 222 | + serialized, |
| 223 | + "\"722c8c993fd75a7627d69ed941344fe2a1423a3e75efd3e6778a142884227104\"" |
| 224 | + ); |
| 225 | + |
| 226 | + let deserialized: Checksum = serde_json::from_str(&serialized).unwrap(); |
| 227 | + assert_eq!(deserialized, checksum); |
| 228 | + } |
| 229 | +} |
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