feat: no_std compatibility (#8)

* wip: no_std compatibility

* feat: the only issue is the use of HashMap and rand

* no std compatibility

* order

* dep cleanup

examples/script/Cargo.toml

@@ -8,7 +8,6 @@ clap = { version = "4.0", features = ["derive", "env"] }
 hex = "0.4.3"
 num-bigint = "0.4.6"
 num-traits = "0.2.19"
-sp1-prover = "2.0.0"
 sp1-sdk = "2.0.0"
 strum = "0.25"
 strum_macros = "0.25"

verifier/Cargo.toml

@@ -13,9 +13,6 @@ version = "1.0.2"
 
 [dependencies]
 bn = { git = "https://github.com/sp1-patches/bn", branch = "patch-v0.7.0", package = "substrate-bn" }
-lazy_static = "1.5.0"
-num-bigint = "0.4.6"
-num-traits = "0.2.19"
 rand = "0.8.5"
 sha2 = "0.10.8"
-thiserror = "1.0.63"
+thiserror-no-std = "2.0.2"

verifier/src/converter.rs

@@ -1,4 +1,4 @@
-use std::cmp::Ordering;
+use core::cmp::Ordering;
 
 use bn::{AffineG1, AffineG2, Fq, Fq2};
 

verifier/src/error.rs

@@ -1,5 +1,5 @@
 use bn::{CurveError, FieldError, GroupError};
-use thiserror::Error;
+use thiserror_no_std::Error;
 
 #[derive(Error, Debug)]
 pub enum Error {

verifier/src/groth16/converter.rs

@@ -1,3 +1,4 @@
+use alloc::{vec, vec::Vec};
 use bn::AffineG1;
 
 use crate::{

verifier/src/groth16/error.rs

@@ -1,4 +1,4 @@
-use thiserror::Error;
+use thiserror_no_std::Error;
 
 #[derive(Debug, Error)]
 pub enum Groth16Error {

verifier/src/groth16/verify.rs

@@ -1,3 +1,4 @@
+use alloc::vec::Vec;
 use bn::{pairing, pairing_batch, AffineG1, AffineG2, Fr, Gt, G1, G2};
 
 use super::error::Groth16Error;

verifier/src/hash_to_field.rs

@@ -1,3 +1,5 @@
+use alloc::vec;
+use alloc::vec::Vec;
 use core::hash::Hasher;
 use sha2::Digest;
 

verifier/src/lib.rs

@@ -3,6 +3,8 @@
 #![deny(missing_docs)]
 
 //! This crate provides verifiers for Groth16 and Plonk zero-knowledge proofs.
+#![no_std]
+extern crate alloc;
 
 use bn::Fr;
 use groth16::{

verifier/src/plonk/converter.rs

@@ -5,6 +5,7 @@ use crate::{
     },
     error::Error,
 };
+use alloc::vec::Vec;
 use bn::{AffineG1, Fr, G2};
 
 use super::{

verifier/src/plonk/error.rs

@@ -1,4 +1,4 @@
-use thiserror::Error;
+use thiserror_no_std::Error;
 
 #[derive(Error, Debug)]
 pub enum PlonkError {

verifier/src/plonk/kzg.rs

@@ -1,3 +1,4 @@
+use alloc::{string::ToString, vec, vec::Vec};
 use bn::{pairing_batch, AffineG1, Fr, G1, G2};
 use rand::rngs::OsRng;
 

verifier/src/plonk/proof.rs

@@ -1,3 +1,5 @@
+use alloc::vec::Vec;
+
 use super::kzg::{BatchOpeningProof, Digest, OpeningProof};
 
 #[derive(Debug)]

verifier/src/plonk/verify.rs

@@ -1,3 +1,4 @@
+use alloc::{string::ToString, vec, vec::Vec};
 use bn::{arith::U256, AffineG1, Fr};
 use core::hash::Hasher;
 

verifier/src/transcript.rs

@@ -1,5 +1,5 @@
+use alloc::{collections::btree_map::BTreeMap, string::String, vec::Vec};
 use sha2::{Digest, Sha256};
-use std::collections::HashMap;
 
 use crate::error::Error;
 
@@ -15,7 +15,7 @@ pub(crate) struct Challenge {
 pub(crate) struct Transcript {
     pub(crate) h: Sha256,
 
-    pub(crate) challenges: HashMap<String, Challenge>,
+    pub(crate) challenges: BTreeMap<String, Challenge>,
     previous_challenge: Option<Challenge>,
 }
 
@@ -24,7 +24,7 @@ impl Transcript {
         let h = Sha256::new();
 
         if let Some(challenges_id) = challenges_id {
-            let mut challenges = HashMap::new();
+            let mut challenges = BTreeMap::new();
             for (position, id) in challenges_id.iter().enumerate() {
                 challenges.insert(
                     id.clone(),
@@ -45,7 +45,7 @@ impl Transcript {
         } else {
             Ok(Transcript {
                 h,
-                challenges: HashMap::new(),
+                challenges: BTreeMap::new(),
                 previous_challenge: None,
             })
         }