Add Wallet, Partial Wallet and Payment to and from bytes converstion

common/nym_offline_compact_ecash/src/proofs/proof_spend.rs

@@ -7,7 +7,7 @@ use crate::error::{CompactEcashError, Result};
 use crate::proofs::{ChallengeDigest, compute_challenge, produce_response, produce_responses};
 use crate::scheme::keygen::VerificationKeyAuth;
 use crate::scheme::setup::Parameters;
-use crate::utils::{try_deserialize_g1_projective, try_deserialize_g2_projective};
+use crate::utils::{try_deserialize_g1_projective, try_deserialize_g2_projective, try_deserialize_scalar_vec, try_deserialize_scalar};
 
 #[derive(Debug)]
 #[cfg_attr(test, derive(PartialEq))]
@@ -207,7 +207,7 @@ pub struct SpendWitness {
     pub r_k: Vec<Scalar>,
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct SpendProof {
     challenge: Scalar,
     response_r: Scalar,
@@ -353,6 +353,7 @@ impl SpendProof {
             response_attributes,
         }
     }
+
     pub fn verify(
         &self,
         params: &Parameters,
@@ -464,6 +465,210 @@ impl SpendProof {
 
         challenge == self.challenge
     }
+
+    pub fn to_bytes(&self) -> Vec<u8> {
+        let challenge_bytes = self.challenge.to_bytes();
+        let response_r_bytes = self.response_r.to_bytes();
+
+        let rrl_len = self.response_r_l.len();
+        let rrl_len_bytes = rrl_len.to_le_bytes();
+
+        let rl_len = self.response_l.len();
+        let rl_len_bytes = rl_len.to_le_bytes();
+
+        let roa_len = self.response_o_a.len();
+        let roa_len_bytes = roa_len.to_le_bytes();
+
+        let roc_bytes = self.response_o_c.to_bytes();
+
+        let rmu_len = self.response_mu.len();
+        let rmu_len_bytes = rmu_len.to_le_bytes();
+
+        let romu_len = self.response_o_mu.len();
+        let romu_len_bytes = romu_len.to_le_bytes();
+
+        let rattributes_len = self.response_attributes.len();
+        let rattributes_len_bytes = rattributes_len.to_le_bytes();
+
+        let mut bytes: Vec<u8> = Vec::with_capacity(
+            96 + (rrl_len + rl_len + roa_len + rmu_len + romu_len + rattributes_len) * 8
+                + (rrl_len + rl_len + roa_len + rmu_len + romu_len + rattributes_len) * 32);
+
+        bytes.extend_from_slice(&challenge_bytes);
+        bytes.extend_from_slice(&response_r_bytes);
+        bytes.extend_from_slice(&roc_bytes);
+
+        bytes.extend_from_slice(&rrl_len_bytes);
+        for rrl in &self.response_r_l {
+            bytes.extend_from_slice(&rrl.to_bytes());
+        }
+
+        bytes.extend_from_slice(&rl_len_bytes);
+        for rl in &self.response_l {
+            bytes.extend_from_slice(&rl.to_bytes());
+        }
+
+        bytes.extend_from_slice(&roa_len_bytes);
+        for roa in &self.response_o_a {
+            bytes.extend_from_slice(&roa.to_bytes());
+        }
+
+        bytes.extend_from_slice(&rmu_len_bytes);
+        for rmu in &self.response_mu {
+            bytes.extend_from_slice(&rmu.to_bytes());
+        }
+
+        bytes.extend_from_slice(&romu_len_bytes);
+        for romu in &self.response_o_mu {
+            bytes.extend_from_slice(&romu.to_bytes());
+        }
+
+        bytes.extend_from_slice(&rattributes_len_bytes);
+        for rattr in &self.response_attributes {
+            bytes.extend_from_slice(&rattr.to_bytes());
+        }
+
+        bytes
+
+    }
+
+}
+
+impl TryFrom<&[u8]> for SpendProof {
+    type Error = CompactEcashError;
+
+    fn try_from(bytes: &[u8]) -> Result<SpendProof> {
+        if bytes.len() < 336 || (bytes.len() - 96 - 48) % 32 != 0 {
+            return Err(CompactEcashError::Deserialization(
+                "tried to deserialize proof of spending with bytes of invalid length"
+                    .to_string(),
+            ));
+        }
+
+        let mut idx = 0;
+        let challenge_bytes = bytes[idx..idx + 32].try_into().unwrap();
+        idx += 32;
+        let response_r_bytes = bytes[idx..idx + 32].try_into().unwrap();
+        idx += 32;
+        let response_o_c_bytes = bytes[idx..idx + 32].try_into().unwrap();
+        idx += 32;
+
+        let challenge = try_deserialize_scalar(
+            &challenge_bytes,
+            CompactEcashError::Deserialization("Failed to deserialize challenge".to_string()),
+        )?;
+
+        let response_r = try_deserialize_scalar(
+            &response_r_bytes,
+            CompactEcashError::Deserialization("Failed to deserialize response_r".to_string()),
+        )?;
+
+        let response_o_c = try_deserialize_scalar(
+            &response_o_c_bytes,
+            CompactEcashError::Deserialization("Failed to deserialize response_o_c".to_string()),
+        )?;
+
+        let rrl_len = u64::from_le_bytes(bytes[idx..idx + 8].try_into().unwrap());
+        idx += 8;
+        if bytes[idx..].len() < rrl_len as usize * 32 {
+            return Err(
+                CompactEcashError::Deserialization(
+                    "tried to deserialize response_r_l".to_string()),
+            );
+        }
+        let rrl_end = idx + rrl_len as usize * 32;
+        let response_r_l = try_deserialize_scalar_vec(
+            rrl_len,
+            &bytes[idx..rrl_end],
+            CompactEcashError::Deserialization("Failed to deserialize response_r_l".to_string()),
+        )?;
+
+        let rl_len = u64::from_le_bytes(bytes[rrl_end..rrl_end + 8].try_into().unwrap());
+        let response_l_start = rrl_end + 8;
+        if bytes[response_l_start..].len() < rl_len as usize * 32 {
+            return Err(CompactEcashError::Deserialization(
+                "tried to deserialize response_l".to_string(),
+            ));
+        }
+        let rl_end = response_l_start + rl_len as usize * 32;
+        let response_l = try_deserialize_scalar_vec(
+            rl_len,
+            &bytes[response_l_start..rl_end],
+            CompactEcashError::Deserialization("Failed to deserialize response_l".to_string()),
+        )?;
+
+        let roa_len = u64::from_le_bytes(bytes[rl_end..rl_end + 8].try_into().unwrap());
+        let roa_end = rl_end + 8;
+        if bytes[roa_end..].len() < roa_len as usize * 32 {
+            return Err(CompactEcashError::Deserialization(
+                "tried to deserialize response_o_a".to_string(),
+            ));
+        }
+        let roa_end = roa_end + roa_len as usize * 32;
+        let response_o_a = try_deserialize_scalar_vec(
+            roa_len,
+            &bytes[rl_end + 8..roa_end],
+            CompactEcashError::Deserialization("Failed to deserialize response_o_a".to_string()),
+        )?;
+
+        let response_mu_len = u64::from_le_bytes(bytes[roa_end..roa_end + 8].try_into().unwrap());
+        let response_mu_end = roa_end + 8;
+        if bytes[response_mu_end..].len() < response_mu_len as usize * 32 {
+            return Err(CompactEcashError::Deserialization(
+                "tried to deserialize response_mu".to_string(),
+            ));
+        }
+        let response_mu_end = response_mu_end + response_mu_len as usize * 32;
+        let response_mu = try_deserialize_scalar_vec(
+            response_mu_len,
+            &bytes[roa_end + 8..response_mu_end],
+            CompactEcashError::Deserialization("Failed to deserialize response_mu".to_string()),
+        )?;
+
+        let response_o_mu_len = u64::from_le_bytes(bytes[response_mu_end..response_mu_end + 8].try_into().unwrap());
+        let response_o_mu_end = response_mu_end + 8;
+        if bytes[response_o_mu_end..].len() < response_o_mu_len as usize * 32 {
+            return Err(CompactEcashError::Deserialization(
+                "tried to deserialize response_o_mu".to_string(),
+            ));
+        }
+        let response_o_mu_end = response_o_mu_end + response_o_mu_len as usize * 32;
+        let response_o_mu = try_deserialize_scalar_vec(
+            response_o_mu_len,
+            &bytes[response_mu_end + 8..response_o_mu_end],
+            CompactEcashError::Deserialization("Failed to deserialize response_o_mu".to_string()),
+        )?;
+
+        let response_attributes_len = u64::from_le_bytes(bytes[response_o_mu_end..response_o_mu_end + 8].try_into().unwrap());
+        let response_attributes_end = response_o_mu_end + 8;
+        if bytes[response_attributes_end..].len() < response_attributes_len as usize * 32 {
+            return Err(CompactEcashError::Deserialization(
+                "tried to deserialize response_attributes".to_string(),
+            ));
+        }
+        let response_attributes_end = response_attributes_end + response_attributes_len as usize * 32;
+        let response_attributes = try_deserialize_scalar_vec(
+            response_attributes_len,
+            &bytes[response_o_mu_end + 8..response_attributes_end],
+            CompactEcashError::Deserialization("Failed to deserialize response_attributes".to_string()),
+        )?;
+
+
+        // Construct the SpendProof struct from the deserialized data
+        let spend_proof = SpendProof {
+            challenge,
+            response_r,
+            response_o_c,
+            response_r_l,
+            response_l,
+            response_o_a,
+            response_mu,
+            response_o_mu,
+            response_attributes,
+        };
+
+        Ok(spend_proof)
+    }
 }
 
 #[cfg(test)]
@@ -563,6 +768,10 @@ mod tests {
         };
 
         let zk_proof = SpendProof::construct(&params, &instance, &witness, &verification_key, &[rr]);
-        assert!(zk_proof.verify(&params, &instance, &verification_key, &[rr]))
+        assert!(zk_proof.verify(&params, &instance, &verification_key, &[rr]));
+
+        let zk_proof_bytes = zk_proof.to_bytes();
+        let zk_proof2 = SpendProof::try_from(zk_proof_bytes.as_slice()).unwrap();
+        assert_eq!(zk_proof, zk_proof2);
     }
 }

common/nym_offline_compact_ecash/src/proofs/proof_withdrawal.rs

@@ -8,7 +8,7 @@ use crate::error::{CompactEcashError, Result};
 use crate::proofs::{ChallengeDigest, compute_challenge, produce_response, produce_responses};
 use crate::scheme::keygen::PublicKeyUser;
 use crate::scheme::setup::GroupParameters;
-use crate::utils::try_deserialize_g1_projective;
+use crate::utils::{try_deserialize_g1_projective, try_deserialize_scalar_vec, try_deserialize_scalar};
 
 #[derive(Debug)]
 #[cfg_attr(test, derive(PartialEq))]
@@ -115,6 +115,7 @@ pub struct WithdrawalReqWitness {
     pub pc_coms_openings: Vec<Scalar>,
 }
 
+#[derive(Debug, PartialEq)]
 pub struct WithdrawalReqProof {
     challenge: Scalar,
     response_opening: Scalar,
@@ -244,8 +245,89 @@ impl WithdrawalReqProof {
 
         challenge == self.challenge
     }
+
+    pub fn to_bytes(&self) -> Vec<u8>{
+        let challenge_bytes = self.challenge.to_bytes();
+        let response_opening_bytes = self.response_opening.to_bytes();
+        let ro_len = self.response_openings.len() as u64;
+        let ra_len = self.response_attributes.len() as u64;
+
+        let mut bytes = Vec::with_capacity(32 + 32 + 8 + ro_len as usize * 32 + 8 + ra_len as usize * 32);
+        bytes.extend_from_slice(&challenge_bytes);
+        bytes.extend_from_slice(&response_opening_bytes);
+        bytes.extend_from_slice(&ro_len.to_le_bytes());
+        for ro in &self.response_openings {
+            bytes.extend_from_slice(&ro.to_bytes());
+        }
+        bytes.extend_from_slice(&ra_len.to_le_bytes());
+        for ra in &self.response_attributes {
+            bytes.extend_from_slice(&ra.to_bytes());
+        }
+        bytes
+    }
 }
 
+impl TryFrom<&[u8]> for WithdrawalReqProof {
+    type Error = CompactEcashError;
+
+    fn try_from(bytes: &[u8]) -> Result<WithdrawalReqProof> {
+        if bytes.len() < 32 + 32 + 16 + 32 + 32 || (bytes.len() - 16) % 32 != 0 {
+            return Err(CompactEcashError::Deserialization(
+                "tried to deserialize proof of withdrawal with bytes of invalid length"
+                    .to_string(),
+            ));
+        }
+
+        let mut idx = 0;
+        let challenge_bytes = bytes[idx..idx + 32].try_into().unwrap();
+        idx += 32;
+        let response_opening_bytes = bytes[idx..idx + 32].try_into().unwrap();
+        idx += 32;
+
+        let challenge = try_deserialize_scalar(
+            &challenge_bytes,
+            CompactEcashError::Deserialization("Failed to deserialize challenge".to_string()),
+        )?;
+
+        let response_opening = try_deserialize_scalar(
+            &response_opening_bytes,
+            CompactEcashError::Deserialization(
+                "Failed to deserialize the response to the random".to_string(),
+            ),
+        )?;
+
+        let ro_len = u64::from_le_bytes(bytes[idx..idx + 8].try_into().unwrap());
+        idx += 8;
+        if bytes[idx..].len() < ro_len as usize * 32 + 8 {
+            return Err(
+                CompactEcashError::Deserialization(
+                    "tried to deserialize response openings".to_string()),
+            );
+        }
+        let ro_end = idx + ro_len as usize * 32;
+        let response_openings = try_deserialize_scalar_vec(
+            ro_len,
+            &bytes[idx..ro_end],
+            CompactEcashError::Deserialization("Failed to deserialize openings response".to_string()),
+        )?;
+
+        let ra_len = u64::from_le_bytes(bytes[ro_end..ro_end + 8].try_into().unwrap());
+        let response_attributes = try_deserialize_scalar_vec(
+            ra_len,
+            &bytes[ro_end + 8..],
+            CompactEcashError::Deserialization("Failed to deserialize attributes response".to_string()),
+        )?;
+
+        Ok(WithdrawalReqProof{
+            challenge,
+            response_opening,
+            response_openings,
+            response_attributes,
+        })
+    }
+}
+
+
 #[cfg(test)]
 mod tests {
     use group::Group;

common/nym_offline_compact_ecash/src/scheme/mod.rs

@@ -10,6 +10,7 @@ use crate::scheme::keygen::{SecretKeyUser, VerificationKeyAuth};
 use crate::scheme::setup::{GroupParameters, Parameters};
 use crate::utils::{
     check_bilinear_pairing, hash_to_scalar, Signature, SignerIndex,
+    try_deserialize_g1_projective, try_deserialize_scalar, try_deserialize_g2_projective,
 };
 
 pub mod aggregation;
@@ -18,6 +19,7 @@ pub mod keygen;
 pub mod setup;
 pub mod withdrawal;
 
+#[derive(Debug, Clone, PartialEq)]
 pub struct PartialWallet {
     sig: Signature,
     v: Scalar,
@@ -34,8 +36,49 @@ impl PartialWallet {
     pub fn index(&self) -> Option<SignerIndex> {
         self.idx
     }
+    pub fn to_bytes(&self) -> [u8; 136]{
+        let mut bytes = [0u8; 136];
+        bytes[0..96].copy_from_slice(&self.sig.to_bytes());
+        bytes[96..128].copy_from_slice(&self.v.to_bytes());
+        // Check if idx is Some and copy its bytes if it exists
+        if let Some(idx) = &self.idx {
+            bytes[128..136].copy_from_slice(&idx.to_le_bytes());
+        }
+        bytes
+    }
 }
 
+impl TryFrom<&[u8]> for PartialWallet {
+    type Error = CompactEcashError;
+
+    fn try_from(bytes: &[u8]) -> Result<PartialWallet> {
+        if bytes.len() != 136 {
+            return Err(CompactEcashError::Deserialization(format!(
+                "PartialWallet should be exactly 136 bytes, got {}",
+                bytes.len()
+            )));
+        }
+
+        let sig_bytes: &[u8; 96] = &bytes[..96].try_into().expect("Slice size != 96");
+        let v_bytes: &[u8; 32] = &bytes[96..128].try_into().expect("Slice size != 32");
+        let idx_bytes: &[u8; 8] = &bytes[128..136].try_into().expect("Slice size != 8");
+
+        let sig = Signature::try_from(sig_bytes.as_slice()).unwrap();
+        let v = Scalar::from_bytes(&v_bytes).unwrap();
+        let idx = None;
+        if !idx_bytes.iter().all(|&x| x == 0){
+            let idx = Some(u64::from_le_bytes(*idx_bytes));
+        }
+
+        Ok(PartialWallet{
+            sig,
+            v,
+            idx,
+        })
+    }
+}
+
+#[derive(Debug, Clone, PartialEq)]
 pub struct Wallet {
     sig: Signature,
     v: Scalar,
@@ -46,13 +89,22 @@ impl Wallet {
     pub fn signature(&self) -> &Signature {
         &self.sig
     }
+
     pub fn v(&self) -> Scalar {
         self.v
     }
+
     pub fn l(&self) -> u64 {
         self.l.get()
     }
 
+    pub fn to_bytes(&self) -> [u8; 136]{
+        let mut bytes = [0u8; 136];
+        bytes[0..96].copy_from_slice(&self.sig.to_bytes());
+        bytes[96..128].copy_from_slice(&self.v.to_bytes());
+        bytes[128..136].copy_from_slice(&self.l.get().to_le_bytes());
+        bytes
+    }
     fn up(&self) {
         self.l.set(self.l.get() + 1);
     }
@@ -203,6 +255,33 @@ impl Wallet {
     }
 }
 
+impl TryFrom<&[u8]> for Wallet {
+    type Error = CompactEcashError;
+
+    fn try_from(bytes: &[u8]) -> Result<Wallet> {
+        if bytes.len() != 136 {
+            return Err(CompactEcashError::Deserialization(format!(
+                "Wallet should be exactly 136 bytes, got {}",
+                bytes.len()
+            )));
+        }
+
+        let sig_bytes: &[u8; 96] = &bytes[..96].try_into().expect("Slice size != 96");
+        let v_bytes: &[u8; 32] = &bytes[96..128].try_into().expect("Slice size != 32");
+        let l_bytes: &[u8; 8] = &bytes[128..136].try_into().expect("Slice size != 8");
+
+        let sig = Signature::try_from(sig_bytes.as_slice()).unwrap();
+        let v = Scalar::from_bytes(&v_bytes).unwrap();
+        let l = Cell::new(u64::from_le_bytes(*l_bytes));
+
+        Ok(Wallet{
+            sig,
+            v,
+            l
+        })
+    }
+}
+
 pub fn pseudorandom_f_delta_v(params: &GroupParameters, v: Scalar, l: u64) -> G1Projective {
     let pow = (v + Scalar::from(l) + Scalar::from(1)).invert().unwrap();
     params.delta() * pow
@@ -233,7 +312,7 @@ pub struct PayInfo {
     pub info: [u8; 32],
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct Payment {
     pub kappa: G2Projective,
     pub sig: Signature,
@@ -320,4 +399,195 @@ impl Payment {
 
         Ok(true)
     }
+
+    pub fn to_bytes(&self) -> Vec<u8>{
+        let kappa_bytes = self.kappa.to_affine().to_compressed();
+        let sig_bytes = self.sig.to_bytes();
+        let cc_bytes = self.cc.to_affine().to_compressed();
+        let vv_bytes: [u8; 8] = self.vv.to_le_bytes();
+        let ss_len =  self.ss.len() as u64;
+        let tt_len =  self.tt.len() as u64;
+        let aa_len =  self.aa.len() as u64;
+        let rr_len =  self.rr.len() as u64;
+        let kappa_k_len = self.kappa_k.len() as u64;
+        let sig_lk_len = self.sig_lk.len() as u64;
+        let zk_proof_bytes = self.zk_proof.to_bytes();
+        let zk_proof_bytes_len = self.zk_proof.to_bytes().len() as u64;
+
+        let mut bytes: Vec<u8> = Vec::with_capacity(
+            (96 + 96 + 48 + 8 + ss_len * 48 + 8 + tt_len * 48 + 8 + aa_len * 48 + 8 + rr_len * 32 + 8 + kappa_k_len * 96 + 8 + sig_lk_len * 96 + zk_proof_bytes_len) as usize);
+
+
+        bytes.extend_from_slice(&kappa_bytes);
+        bytes.extend_from_slice(&sig_bytes);
+        bytes.extend_from_slice(&cc_bytes);
+        bytes.extend_from_slice(&vv_bytes);
+
+
+        let ss_len_bytes = ss_len.to_le_bytes();
+        bytes.extend_from_slice(&ss_len_bytes);
+        for s in &self.ss {
+            bytes.extend_from_slice(&s.to_affine().to_compressed());
+        }
+
+        let tt_len_bytes = tt_len.to_le_bytes();
+        bytes.extend_from_slice(&tt_len_bytes);
+        for t in &self.tt {
+            bytes.extend_from_slice(&t.to_affine().to_compressed());
+        }
+
+        let aa_len_bytes = aa_len.to_le_bytes();
+        bytes.extend_from_slice(&aa_len_bytes);
+        for a in &self.aa {
+            bytes.extend_from_slice(&a.to_affine().to_compressed());
+        }
+
+        let rr_len_bytes = rr_len.to_le_bytes();
+        bytes.extend_from_slice(&rr_len_bytes);
+        for r in &self.rr {
+            bytes.extend_from_slice(&r.to_bytes());
+        }
+
+        let kappa_k_len_bytes = kappa_k_len.to_le_bytes();
+        bytes.extend_from_slice(&kappa_k_len_bytes);
+        for kk in &self.kappa_k {
+            bytes.extend_from_slice(&kk.to_affine().to_compressed());
+        }
+
+        let sig_lk_len_bytes = sig_lk_len.to_le_bytes();
+        bytes.extend_from_slice(&sig_lk_len_bytes);
+        for sig in &self.sig_lk {
+            bytes.extend_from_slice(&sig.to_bytes());
+        }
+
+        bytes.extend_from_slice(&zk_proof_bytes);
+        bytes
+    }
 }
+
+impl TryFrom<&[u8]> for Payment {
+    type Error = CompactEcashError;
+
+    fn try_from(bytes: &[u8]) -> Result<Payment> {
+        if bytes.len() < 656 {
+            return Err(CompactEcashError::Deserialization(
+                "Invalid byte array for Payment deserialization".to_string(),
+            ));
+        }
+
+        let kappa_bytes: [u8; 96] = bytes[..96].try_into().unwrap();
+        let sig_bytes: [u8; 96] = bytes[96..192].try_into().unwrap();
+        let cc_bytes: [u8; 48] = bytes[192..240].try_into().unwrap();
+        let vv_bytes: [u8; 8] = bytes[240..248].try_into().unwrap();
+        let ss_len = u64::from_le_bytes(bytes[248..256].try_into().unwrap()) as usize;
+
+        // Convert the byte arrays back into their respective types
+        let kappa = try_deserialize_g2_projective(
+            &kappa_bytes,
+            CompactEcashError::Deserialization("Failed to deserialize kappa".to_string()),
+        )?;
+        let sig = Signature::try_from(sig_bytes.as_slice())?;
+
+        let cc = try_deserialize_g1_projective(
+            &cc_bytes,
+            CompactEcashError::Deserialization("Failed to deserialize cc".to_string()),
+        )?;
+        let vv = u64::from_le_bytes(vv_bytes);
+
+        let mut idx = 256;
+        let mut ss = Vec::with_capacity(ss_len);
+        for _ in 0..ss_len {
+            let ss_bytes: [u8; 48] = bytes[idx..idx + 48].try_into().unwrap();
+            let ss_elem = try_deserialize_g1_projective(
+                &ss_bytes,
+                CompactEcashError::Deserialization("Failed to deserialize ss element".to_string()),
+            )?;
+            ss.push(ss_elem);
+            idx += 48;
+        }
+
+        let tt_len = u64::from_le_bytes(bytes[idx..idx+8].try_into().unwrap()) as usize;
+        idx += 8;
+        let mut tt = Vec::with_capacity(tt_len);
+        for _ in 0..tt_len {
+            let tt_bytes: [u8; 48] = bytes[idx..idx + 48].try_into().unwrap();
+            let tt_elem = try_deserialize_g1_projective(
+                &tt_bytes,
+                CompactEcashError::Deserialization("Failed to deserialize tt element".to_string()),
+            )?;
+            tt.push(tt_elem);
+            idx += 48;
+        }
+
+        let aa_len = u64::from_le_bytes(bytes[idx..idx+8].try_into().unwrap()) as usize;
+        idx += 8;
+        let mut aa = Vec::with_capacity(aa_len);
+        for _ in 0..aa_len {
+            let aa_bytes: [u8; 48] = bytes[idx..idx + 48].try_into().unwrap();
+            let aa_elem = try_deserialize_g1_projective(
+                &aa_bytes,
+                CompactEcashError::Deserialization("Failed to deserialize aa element".to_string()),
+            )?;
+            aa.push(aa_elem);
+            idx += 48;
+        }
+
+        let rr_len = u64::from_le_bytes(bytes[idx..idx+8].try_into().unwrap()) as usize;
+        idx += 8;
+        let mut rr = Vec::with_capacity(rr_len);
+        for _ in 0..rr_len {
+            let rr_bytes: [u8; 32] = bytes[idx..idx + 32].try_into().unwrap();
+            let rr_elem = try_deserialize_scalar(
+                &rr_bytes,
+                CompactEcashError::Deserialization("Failed to deserialize rr element".to_string()),
+            )?;
+            rr.push(rr_elem);
+            idx += 32;
+        }
+
+        let kappa_k_len = u64::from_le_bytes(bytes[idx..idx+8].try_into().unwrap()) as usize;
+        idx += 8;
+        let mut kappa_k = Vec::with_capacity(kappa_k_len);
+        for _ in 0..kappa_k_len {
+            let kappa_k_bytes: [u8; 96] = bytes[idx..idx + 96].try_into().unwrap();
+            let kappa_k_elem = try_deserialize_g2_projective(
+                &kappa_k_bytes,
+                CompactEcashError::Deserialization("Failed to deserialize kappa_k element".to_string()),
+            )?;
+            kappa_k.push(kappa_k_elem);
+            idx += 96;
+        }
+
+        // sig_lk
+        let sig_lk_len = u64::from_le_bytes(bytes[idx..idx+8].try_into().unwrap()) as usize;
+        idx += 8;
+        let mut sig_lk = Vec::with_capacity(sig_lk_len);
+        for _ in 0..sig_lk_len {
+            let sig_lk_bytes: [u8; 96] = bytes[idx..idx + 96].try_into().unwrap();
+            let sig_lk_elem = Signature::try_from(sig_lk_bytes.as_slice())?;
+            sig_lk.push(sig_lk_elem);
+            idx += 96;
+        }
+
+        // Deserialize the SpendProof struct
+        let zk_proof_bytes = &bytes[idx..];
+        let zk_proof = SpendProof::try_from(zk_proof_bytes)?;
+
+        // Construct the Payment struct from the deserialized data
+        let payment = Payment {
+            kappa,
+            sig,
+            ss,
+            tt,
+            aa,
+            rr,
+            kappa_k,
+            sig_lk,
+            cc,
+            zk_proof,
+            vv,
+        };
+
+        Ok(payment)
+    }
+}

common/nym_offline_compact_ecash/src/scheme/withdrawal.rs

@@ -8,9 +8,10 @@ use crate::proofs::proof_withdrawal::{
 use crate::scheme::keygen::{PublicKeyUser, SecretKeyAuth, SecretKeyUser, VerificationKeyAuth};
 use crate::scheme::PartialWallet;
 use crate::scheme::setup::GroupParameters;
-use crate::utils::{check_bilinear_pairing, hash_g1};
+use crate::utils::{check_bilinear_pairing, hash_g1, try_deserialize_g1_projective};
 use crate::utils::{BlindedSignature, Signature};
 
+#[derive(Debug, PartialEq)]
 pub struct WithdrawalRequest {
     com_hash: G1Projective,
     com: G1Projective,
@@ -18,6 +19,96 @@ pub struct WithdrawalRequest {
     zk_proof: WithdrawalReqProof,
 }
 
+impl WithdrawalRequest {
+    pub fn to_bytes(&self) -> Vec<u8>{
+        let com_hash_bytes = self.com_hash.to_affine().to_compressed();
+        let com_bytes = self.com.to_affine().to_compressed();
+        let pr_coms_len = self.pc_coms.len() as u64;
+        let zk_proof_bytes = self.zk_proof.to_bytes();
+
+        let mut bytes = Vec::with_capacity(48 + 48 + 8 + pr_coms_len as usize * 48 + zk_proof_bytes.len());
+        bytes.extend_from_slice(&com_hash_bytes);
+        bytes.extend_from_slice(&com_bytes);
+        bytes.extend_from_slice(&pr_coms_len.to_le_bytes());
+        for c in &self.pc_coms {
+            bytes.extend_from_slice(&c.to_affine().to_compressed());
+        }
+
+        bytes.extend_from_slice(&zk_proof_bytes);
+
+        bytes
+
+    }
+}
+
+impl TryFrom<&[u8]> for WithdrawalRequest {
+    type Error = CompactEcashError;
+
+    fn try_from(bytes: &[u8]) -> Result<WithdrawalRequest> {
+        if bytes.len() < 48 + 48 + 8 + 48{
+            return Err(CompactEcashError::DeserializationMinLength {
+                min: 48 + 48 + 8 + 48,
+                actual: bytes.len(),
+            });
+        }
+
+        let mut j = 0;
+        let commitment_hash_bytes_len = 48;
+        let commitment_bytes_len = 48;
+
+        let com_hash_bytes = bytes[..j + commitment_hash_bytes_len].try_into().unwrap();
+        let com_hash = try_deserialize_g1_projective(
+            &com_hash_bytes,
+            CompactEcashError::Deserialization(
+                "Failed to deserialize compressed commitment hash".to_string(),
+            ),
+        )?;
+        j += commitment_hash_bytes_len;
+
+        let com_bytes = bytes[j..j + commitment_bytes_len].try_into().unwrap();
+        let com = try_deserialize_g1_projective(
+            &com_bytes,
+            CompactEcashError::Deserialization(
+                "Failed to deserialize compressed commitment".to_string(),
+            ),
+        )?;
+        j += commitment_bytes_len;
+
+        let pc_len = u64::from_le_bytes(bytes[j..j + 8].try_into().unwrap());
+        j += 8;
+        if bytes[j..].len() < pc_len as usize * 48 {
+            return Err(CompactEcashError::DeserializationMinLength {
+                min: pc_len as usize * 48,
+                actual: bytes[56..].len(),
+            });
+        }
+        let mut pc_coms = Vec::with_capacity(pc_len as usize);
+        for i in 0..pc_len as usize {
+            let start = j + i * 48;
+            let end = start + 48;
+
+            let pc_com_bytes = bytes[start..end].try_into().unwrap();
+            let pc_com = try_deserialize_g1_projective(
+                &pc_com_bytes,
+                CompactEcashError::Deserialization(
+                    "Failed to deserialize compressed Pedersen commitment".to_string(),
+                ),
+            )?;
+
+            pc_coms.push(pc_com)
+        }
+
+        let zk_proof = WithdrawalReqProof::try_from(&bytes[j + pc_len as usize * 48..])?;
+
+        Ok(WithdrawalRequest{
+            com_hash,
+            com,
+            pc_coms,
+            zk_proof,
+        })
+    }
+}
+
 pub struct RequestInfo {
     com_hash: G1Projective,
     com_opening: Scalar,

common/nym_offline_compact_ecash/src/tests/e2e.rs

@@ -7,10 +7,10 @@ use crate::scheme::aggregation::{
 use crate::scheme::keygen::{
     generate_keypair_user, ttp_keygen, VerificationKeyAuth,
 };
-use crate::scheme::PartialWallet;
+use crate::scheme::{Wallet, PartialWallet, Payment};
 use crate::scheme::PayInfo;
 use crate::scheme::setup::setup;
-use crate::scheme::withdrawal::{issue_verify, issue_wallet, withdrawal_request};
+use crate::scheme::withdrawal::{issue_verify, issue_wallet, withdrawal_request, WithdrawalRequest};
 
 #[test]
 fn main() -> Result<(), CompactEcashError> {
@@ -20,6 +20,10 @@ fn main() -> Result<(), CompactEcashError> {
     let user_keypair = generate_keypair_user(&grparams);
 
     let (req, req_info) = withdrawal_request(grparams, &user_keypair.secret_key()).unwrap();
+    let req_bytes = req.to_bytes();
+    let req2 = WithdrawalRequest::try_from(req_bytes.as_slice()).unwrap();
+    assert_eq!(req, req2);
+
     let authorities_keypairs = ttp_keygen(&grparams, 2, 3).unwrap();
 
     let verification_keys_auth: Vec<VerificationKeyAuth> = authorities_keypairs
@@ -47,6 +51,11 @@ fn main() -> Result<(), CompactEcashError> {
         .map(|(w, vk)| issue_verify(&grparams, vk, &user_keypair.secret_key(), w, &req_info).unwrap())
         .collect();
 
+    let partial_wallet = unblinded_wallet_shares.get(0).unwrap().clone();
+    let partial_wallet_bytes = partial_wallet.to_bytes();
+    let partial_wallet2 = PartialWallet::try_from(&partial_wallet_bytes[..]).unwrap();
+    assert_eq!(partial_wallet, partial_wallet2);
+
     // Aggregate partial wallets
     let aggr_wallet = aggregate_wallets(
         &grparams,
@@ -56,6 +65,10 @@ fn main() -> Result<(), CompactEcashError> {
         &req_info,
     )?;
 
+    let wallet_bytes = aggr_wallet.to_bytes();
+    let wallet = Wallet::try_from(&wallet_bytes[..]).unwrap();
+    assert_eq!(aggr_wallet, wallet);
+
     // Let's try to spend some coins
     let pay_info = PayInfo { info: [6u8; 32] };
     let spend_vv = 1;
@@ -73,6 +86,10 @@ fn main() -> Result<(), CompactEcashError> {
         .spend_verify(&params, &verification_key, &pay_info)
         .unwrap());
 
+    let payment_bytes = payment.to_bytes();
+    println!("{:?}", payment_bytes.len());
+    let payment2 = Payment::try_from(&payment_bytes[..]).unwrap();
+    assert_eq!(payment, payment2);
 
     Ok(())
 }

common/nym_offline_compact_ecash/src/utils.rs

@@ -199,8 +199,8 @@ pub fn check_bilinear_pairing(p: &G1Affine, q: &G2Prepared, r: &G1Affine, s: &G2
 
 pub type SignerIndex = u64;
 
-#[derive(Debug, Clone, Copy)]
-#[cfg_attr(test, derive(PartialEq))]
+#[derive(Debug, Clone, Copy, PartialEq)]
+// #[cfg_attr(test, derive(PartialEq))]
 pub struct Signature(pub(crate) G1Projective, pub(crate) G1Projective);
 
 pub type PartialSignature = Signature;