1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
/*
 * AquaVM Workflow Engine
 *
 * Copyright (C) 2024 Fluence DAO
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation version 3 of the
 * License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#![forbid(unsafe_code)]
#![warn(rust_2018_idioms)]
#![deny(
    dead_code,
    nonstandard_style,
    unused_imports,
    unused_mut,
    unused_variables,
    unused_unsafe,
    unreachable_patterns
)]

mod verify;

pub use crate::verify::{verify_raw_value, verify_value, CidVerificationError};

use fluence_blake3 as blake3;
use serde::Deserialize;
use serde::Serialize;
use thiserror::Error as ThisError;

use std::fmt;
use std::io::BufWriter;
use std::marker::PhantomData;
use std::rc::Rc;

/// Should-be-opaque type for the inner representation of CID.
/// It has to be serializable and Borsh-serializable, as well as implement `Debug`, `Eq`, `Ord`, `Hash` and similar
/// basic traits.  It is also can be unsized.
// you should be able to replace it with [u8], and most of the code will just work
pub type CidRef = str;

// there is no Rust multicodec crate with appropriate constants
const JSON_CODEC: u64 = 0x0200;

#[derive(Serialize, Deserialize)]
#[serde(transparent)]
#[cfg_attr(
    feature = "rkyv",
    derive(::rkyv::Archive, ::rkyv::Serialize, ::rkyv::Deserialize)
)]
#[cfg_attr(feature = "rkyv", archive(check_bytes))]
#[cfg_attr(feature = "rkyv", omit_bounds)] // TODO look close, may be a misuse
pub struct CID<T: ?Sized>(
    Rc<CidRef>,
    #[serde(skip)]
    #[cfg_attr(feature = "rkyv", with(::rkyv::with::Skip))]
    PhantomData<*const T>,
);

impl<T: ?Sized> CID<T> {
    pub fn new(cid: impl Into<Rc<CidRef>>) -> Self {
        Self(cid.into(), PhantomData)
    }

    pub fn get_inner(&self) -> Rc<CidRef> {
        self.0.clone()
    }
}

impl<T: ?Sized> std::convert::AsRef<CidRef> for CID<T> {
    fn as_ref(&self) -> &CidRef {
        &self.0
    }
}

impl<T: ?Sized> std::borrow::Borrow<CidRef> for CID<T> {
    fn borrow(&self) -> &CidRef {
        &self.0
    }
}

impl<T: ?Sized> Clone for CID<T> {
    fn clone(&self) -> Self {
        Self(self.0.clone(), self.1)
    }
}

impl<T: ?Sized> fmt::Debug for CID<T> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_tuple("CID").field(&self.0).finish()
    }
}

impl<Val> PartialEq for CID<Val> {
    fn eq(&self, other: &Self) -> bool {
        self.0 == other.0
    }
}

impl<Val> Eq for CID<Val> {}

impl<Val> std::hash::Hash for CID<Val> {
    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
        self.0.hash(state);
        self.1.hash(state);
    }
}

impl<T: ?Sized> std::convert::TryFrom<&'_ CID<T>> for cid::Cid {
    type Error = cid::Error;

    fn try_from(value: &CID<T>) -> Result<Self, Self::Error> {
        use std::str::FromStr;

        cid::Cid::from_str(&value.0)
    }
}

#[derive(Debug, ThisError)]
pub enum CidCalculationError {
    #[error(transparent)]
    InvalidJson(#[from] serde_json::Error),
}

/// Calculate a CID of JSON-serialized value.
// TODO we might refactor this to `SerializationCodec` trait
// that both transform data to binary/text form (be it JSON, CBOR or something else)
// and produces CID too
pub fn value_to_json_cid<Val: Serialize + ?Sized>(
    value: &Val,
) -> Result<CID<Val>, CidCalculationError> {
    use cid::Cid;
    use multihash_codetable::{Code, MultihashDigest};

    let hash = value_json_hash::<blake3::Hasher, Val>(value)?;

    let digest = Code::Blake3_256
        .wrap(&hash)
        .expect("can't happen: incorrect hash length");

    let cid = Cid::new_v1(JSON_CODEC, digest);
    Ok(CID::new(cid.to_string()))
}

pub(crate) fn value_json_hash<D: digest::Digest + std::io::Write, Val: Serialize + ?Sized>(
    value: &Val,
) -> Result<Vec<u8>, serde_json::Error> {
    const HASH_BUFFER_SIZE: usize = 8 * 1024;

    let mut hasher = D::new();
    serde_json::to_writer(
        BufWriter::with_capacity(HASH_BUFFER_SIZE, &mut hasher),
        value,
    )?;
    let hash = hasher.finalize();

    Ok(hash.to_vec())
}

pub fn raw_value_to_json_cid<Val>(raw_value: impl AsRef<[u8]>) -> CID<Val> {
    use cid::Cid;
    use multihash_codetable::{Code, MultihashDigest};

    let hash = raw_value_hash::<blake3::Hasher>(raw_value);
    let digest = Code::Blake3_256
        .wrap(&hash)
        .expect("can't happen: incorrect hash length");

    let cid = Cid::new_v1(JSON_CODEC, digest);
    CID::new(cid.to_string())
}

pub(crate) fn raw_value_hash<D: digest::Digest>(raw_value: impl AsRef<[u8]>) -> Vec<u8> {
    let mut hasher = D::new();
    hasher.update(raw_value);
    let hash = hasher.finalize();

    hash.to_vec()
}

#[cfg(test)]
mod tests {
    use super::*;
    use serde_json::json;

    #[test]
    fn test_cid_default() {
        assert_eq!(
            value_to_json_cid(&json!("test")).unwrap(),
            CID::new("bagaaihrarcyykpv4oj7zwdbepczyfthxya4og7s2rwvrzolm5kg2eu5dz3xa")
        );
        assert_eq!(
            value_to_json_cid(&json!([1, 2, 3])).unwrap(),
            CID::new("bagaaihram6sitn77tquub77n2jzjgttrlwkverv44pv3gns6qghm6hx6d36a"),
        );
        assert_eq!(
            value_to_json_cid(&json!(1)).unwrap(),
            CID::new("bagaaihra2y55tkbgv6i4d7vdoglfuzhbd3ra6e7ennpvfrmzaejwmbntusdq"),
        );
        assert_eq!(
            value_to_json_cid(&json!({"key": 42})).unwrap(),
            CID::new("bagaaihracpzxhsrpviexa7k6glwdhyh3a4kvy6j7qlcqokzqbs3q424cmxyq"),
        );
    }
}