fix: support builds targeting wasm32 (#298)

* fix: support builds targetting `wasm32`

- Introduced conditional compilation for WASM target architecture in burn.rs, mint.rs, transfer.rs, and transfer_with_fee.rs.

Fixes #293

* ci: add `wasm` build check for `spl-token-2022`

- Introduced a new job in the GitHub Actions workflow to build the Token-2022 for the WASM target architecture.

This should ensure no future regressions.

* style: update formatting

* chore: add WASM build script for programs

- Removed the old `wasm:build` script and introduced `programs:build-wasm` to streamline the build process for WASM targets.
- Added a new `build-wasm.mjs` script to handle the WASM build using Cargo.

* ci: update build script

Author: ifiokjr

.github/workflows/main.yml

@@ -286,6 +286,9 @@ jobs:
       - name: Build Token-2022
         run: pnpm programs:build
 
+      - name: Build Token-2022 Wasm
+        run: pnpm programs:build-wasm
+
       - name: Build ElGamal Registry
         run: pnpm confidential-transfer:elgamal-registry:build
 

confidential-transfer/proof-generation/src/burn.rs

@@ -1,3 +1,5 @@
+#[cfg(target_arch = "wasm32")]
+use solana_zk_sdk::encryption::grouped_elgamal::GroupedElGamalCiphertext3Handles;
 use {
     crate::{
         encryption::BurnAmountCiphertext, errors::TokenProofGenerationError,
@@ -53,14 +55,33 @@ pub fn burn_split_proof_data(
         supply_elgamal_pubkey,
         auditor_elgamal_pubkey,
     );
+    #[cfg(not(target_arch = "wasm32"))]
+    let grouped_ciphertext_lo = burn_amount_ciphertext_lo.0;
+    #[cfg(target_arch = "wasm32")]
+    let grouped_ciphertext_lo = GroupedElGamalCiphertext3Handles::encryption_with_u64(
+        source_elgamal_keypair.pubkey(),
+        supply_elgamal_pubkey,
+        auditor_elgamal_pubkey,
+        burn_amount_lo,
+        &burn_amount_opening_lo,
+    );
 
     let (burn_amount_ciphertext_hi, burn_amount_opening_hi) = BurnAmountCiphertext::new(
         burn_amount_hi,
         source_elgamal_keypair.pubkey(),
         supply_elgamal_pubkey,
         auditor_elgamal_pubkey,
     );
-
+    #[cfg(not(target_arch = "wasm32"))]
+    let grouped_ciphertext_hi = burn_amount_ciphertext_hi.0;
+    #[cfg(target_arch = "wasm32")]
+    let grouped_ciphertext_hi = GroupedElGamalCiphertext3Handles::encryption_with_u64(
+        source_elgamal_keypair.pubkey(),
+        supply_elgamal_pubkey,
+        auditor_elgamal_pubkey,
+        burn_amount_hi,
+        &burn_amount_opening_hi,
+    );
     // decrypt the current available balance at the source
     let current_decrypted_available_balance = current_decryptable_available_balance
         .decrypt(source_aes_key)
@@ -108,8 +129,8 @@ pub fn burn_split_proof_data(
         source_elgamal_keypair.pubkey(),
         supply_elgamal_pubkey,
         auditor_elgamal_pubkey,
-        &burn_amount_ciphertext_lo.0,
-        &burn_amount_ciphertext_hi.0,
+        &grouped_ciphertext_lo,
+        &grouped_ciphertext_hi,
         burn_amount_lo,
         burn_amount_hi,
         &burn_amount_opening_lo,

confidential-transfer/proof-generation/src/mint.rs

@@ -1,3 +1,5 @@
+#[cfg(target_arch = "wasm32")]
+use solana_zk_sdk::encryption::grouped_elgamal::GroupedElGamalCiphertext3Handles;
 use {
     crate::{
         encryption::MintAmountCiphertext, errors::TokenProofGenerationError,
@@ -52,13 +54,33 @@ pub fn mint_split_proof_data(
         supply_elgamal_keypair.pubkey(),
         auditor_elgamal_pubkey,
     );
+    #[cfg(not(target_arch = "wasm32"))]
+    let grouped_ciphertext_lo = mint_amount_grouped_ciphertext_lo.0;
+    #[cfg(target_arch = "wasm32")]
+    let grouped_ciphertext_lo = GroupedElGamalCiphertext3Handles::encryption_with_u64(
+        destination_elgamal_pubkey,
+        supply_elgamal_keypair.pubkey(),
+        auditor_elgamal_pubkey,
+        mint_amount_lo,
+        &mint_amount_opening_lo,
+    );
 
     let (mint_amount_grouped_ciphertext_hi, mint_amount_opening_hi) = MintAmountCiphertext::new(
         mint_amount_hi,
         destination_elgamal_pubkey,
         supply_elgamal_keypair.pubkey(),
         auditor_elgamal_pubkey,
     );
+    #[cfg(not(target_arch = "wasm32"))]
+    let grouped_ciphertext_hi = mint_amount_grouped_ciphertext_hi.0;
+    #[cfg(target_arch = "wasm32")]
+    let grouped_ciphertext_hi = GroupedElGamalCiphertext3Handles::encryption_with_u64(
+        destination_elgamal_pubkey,
+        supply_elgamal_keypair.pubkey(),
+        auditor_elgamal_pubkey,
+        mint_amount_hi,
+        &mint_amount_opening_hi,
+    );
 
     // compute the new supply ciphertext
     let mint_amount_ciphertext_supply_lo = mint_amount_grouped_ciphertext_lo
@@ -101,8 +123,8 @@ pub fn mint_split_proof_data(
         destination_elgamal_pubkey,
         supply_elgamal_keypair.pubkey(),
         auditor_elgamal_pubkey,
-        &mint_amount_grouped_ciphertext_lo.0,
-        &mint_amount_grouped_ciphertext_hi.0,
+        &grouped_ciphertext_lo,
+        &grouped_ciphertext_hi,
         mint_amount_lo,
         mint_amount_hi,
         &mint_amount_opening_lo,

confidential-transfer/proof-generation/src/transfer.rs

@@ -1,3 +1,5 @@
+#[cfg(target_arch = "wasm32")]
+use solana_zk_sdk::encryption::grouped_elgamal::GroupedElGamalCiphertext3Handles;
 use {
     crate::{
         encryption::TransferAmountCiphertext, errors::TokenProofGenerationError,
@@ -55,6 +57,16 @@ pub fn transfer_split_proof_data(
             destination_elgamal_pubkey,
             auditor_elgamal_pubkey,
         );
+    #[cfg(not(target_arch = "wasm32"))]
+    let grouped_ciphertext_lo = transfer_amount_grouped_ciphertext_lo.0;
+    #[cfg(target_arch = "wasm32")]
+    let grouped_ciphertext_lo = GroupedElGamalCiphertext3Handles::encryption_with_u64(
+        source_elgamal_keypair.pubkey(),
+        destination_elgamal_pubkey,
+        auditor_elgamal_pubkey,
+        transfer_amount_lo,
+        &transfer_amount_opening_lo,
+    );
 
     let (transfer_amount_grouped_ciphertext_hi, transfer_amount_opening_hi) =
         TransferAmountCiphertext::new(
@@ -63,6 +75,16 @@ pub fn transfer_split_proof_data(
             destination_elgamal_pubkey,
             auditor_elgamal_pubkey,
         );
+    #[cfg(not(target_arch = "wasm32"))]
+    let grouped_ciphertext_hi = transfer_amount_grouped_ciphertext_hi.0;
+    #[cfg(target_arch = "wasm32")]
+    let grouped_ciphertext_hi = GroupedElGamalCiphertext3Handles::encryption_with_u64(
+        source_elgamal_keypair.pubkey(),
+        destination_elgamal_pubkey,
+        auditor_elgamal_pubkey,
+        transfer_amount_hi,
+        &transfer_amount_opening_hi,
+    );
 
     // Decrypt the current available balance at the source
     let current_decrypted_available_balance = current_decryptable_available_balance
@@ -112,8 +134,8 @@ pub fn transfer_split_proof_data(
         source_elgamal_keypair.pubkey(),
         destination_elgamal_pubkey,
         auditor_elgamal_pubkey,
-        &transfer_amount_grouped_ciphertext_lo.0,
-        &transfer_amount_grouped_ciphertext_hi.0,
+        &grouped_ciphertext_lo,
+        &grouped_ciphertext_hi,
         transfer_amount_lo,
         transfer_amount_hi,
         &transfer_amount_opening_lo,

confidential-transfer/proof-generation/src/transfer_with_fee.rs

@@ -1,3 +1,9 @@
+#[cfg(not(target_arch = "wasm32"))]
+use solana_zk_sdk::encryption::grouped_elgamal::GroupedElGamal;
+#[cfg(target_arch = "wasm32")]
+use solana_zk_sdk::encryption::grouped_elgamal::{
+    GroupedElGamalCiphertext2Handles, GroupedElGamalCiphertext3Handles,
+};
 use {
     crate::{
         encryption::{FeeCiphertext, TransferAmountCiphertext},
@@ -11,7 +17,6 @@ use {
         encryption::{
             auth_encryption::{AeCiphertext, AeKey},
             elgamal::{ElGamalCiphertext, ElGamalKeypair, ElGamalPubkey},
-            grouped_elgamal::GroupedElGamal,
             pedersen::{Pedersen, PedersenCommitment, PedersenOpening},
         },
         zk_elgamal_proof_program::proof_data::{
@@ -71,6 +76,16 @@ pub fn transfer_with_fee_split_proof_data(
             destination_elgamal_pubkey,
             auditor_elgamal_pubkey,
         );
+    #[cfg(not(target_arch = "wasm32"))]
+    let grouped_ciphertext_lo = transfer_amount_grouped_ciphertext_lo.0;
+    #[cfg(target_arch = "wasm32")]
+    let grouped_ciphertext_lo = GroupedElGamalCiphertext3Handles::encryption_with_u64(
+        source_elgamal_keypair.pubkey(),
+        destination_elgamal_pubkey,
+        auditor_elgamal_pubkey,
+        transfer_amount_lo,
+        &transfer_amount_opening_lo,
+    );
 
     let (transfer_amount_grouped_ciphertext_hi, transfer_amount_opening_hi) =
         TransferAmountCiphertext::new(
@@ -79,6 +94,16 @@ pub fn transfer_with_fee_split_proof_data(
             destination_elgamal_pubkey,
             auditor_elgamal_pubkey,
         );
+    #[cfg(not(target_arch = "wasm32"))]
+    let grouped_ciphertext_hi = transfer_amount_grouped_ciphertext_hi.0;
+    #[cfg(target_arch = "wasm32")]
+    let grouped_ciphertext_hi = GroupedElGamalCiphertext3Handles::encryption_with_u64(
+        source_elgamal_keypair.pubkey(),
+        destination_elgamal_pubkey,
+        auditor_elgamal_pubkey,
+        transfer_amount_hi,
+        &transfer_amount_opening_hi,
+    );
 
     // Decrypt the current available balance at the source
     let current_decrypted_available_balance = current_decryptable_available_balance
@@ -130,8 +155,8 @@ pub fn transfer_with_fee_split_proof_data(
             source_elgamal_keypair.pubkey(),
             destination_elgamal_pubkey,
             auditor_elgamal_pubkey,
-            &transfer_amount_grouped_ciphertext_lo.0,
-            &transfer_amount_grouped_ciphertext_hi.0,
+            &grouped_ciphertext_lo,
+            &grouped_ciphertext_hi,
             transfer_amount_lo,
             transfer_amount_hi,
             &transfer_amount_opening_lo,
@@ -233,6 +258,7 @@ pub fn transfer_with_fee_split_proof_data(
 
     // encrypt the fee amount under the destination and withdraw withheld authority
     // ElGamal public key
+    #[cfg(not(target_arch = "wasm32"))]
     let fee_destination_withdraw_withheld_authority_ciphertext_lo = GroupedElGamal::encrypt_with(
         [
             destination_elgamal_pubkey,
@@ -241,6 +267,16 @@ pub fn transfer_with_fee_split_proof_data(
         fee_amount_lo,
         &fee_opening_lo,
     );
+    #[cfg(target_arch = "wasm32")]
+    let fee_destination_withdraw_withheld_authority_ciphertext_lo =
+        GroupedElGamalCiphertext2Handles::encryption_with_u64(
+            destination_elgamal_pubkey,
+            withdraw_withheld_authority_elgamal_pubkey,
+            fee_amount_lo,
+            &fee_opening_lo,
+        );
+
+    #[cfg(not(target_arch = "wasm32"))]
     let fee_destination_withdraw_withheld_authority_ciphertext_hi = GroupedElGamal::encrypt_with(
         [
             destination_elgamal_pubkey,
@@ -249,6 +285,14 @@ pub fn transfer_with_fee_split_proof_data(
         fee_amount_hi,
         &fee_opening_hi,
     );
+    #[cfg(target_arch = "wasm32")]
+    let fee_destination_withdraw_withheld_authority_ciphertext_hi =
+        GroupedElGamalCiphertext2Handles::encryption_with_u64(
+            destination_elgamal_pubkey,
+            withdraw_withheld_authority_elgamal_pubkey,
+            fee_amount_hi,
+            &fee_opening_hi,
+        );
 
     // generate fee ciphertext validity data
     let fee_ciphertext_validity_proof_data =

package.json

@@ -2,6 +2,7 @@
   "private": true,
   "scripts": {
     "programs:build": "zx ./scripts/rust/build-sbf.mjs program",
+    "programs:build-wasm": "zx ./scripts/rust/build-wasm.mjs program",
     "programs:test": "zx ./scripts/rust/test-sbf.mjs program",
     "programs:format": "zx ./scripts/rust/format.mjs program",
     "programs:lint": "zx ./scripts/rust/lint.mjs program",

program/src/extension/confidential_transfer_fee/processor.rs

@@ -29,7 +29,6 @@ use {
         processor::Processor,
         solana_zk_sdk::encryption::pod::elgamal::PodElGamalPubkey,
     },
-    bytemuck::Zeroable,
     solana_account_info::{next_account_info, AccountInfo},
     solana_msg::msg,
     solana_program_error::{ProgramError, ProgramResult},
@@ -38,6 +37,9 @@ use {
     spl_token_confidential_transfer_proof_extraction::instruction::verify_and_extract_context,
 };
 
+#[cfg(not(target_arch = "wasm32"))]
+use bytemuck::Zeroable;
+
 /// Processes an [`InitializeConfidentialTransferFeeConfig`] instruction.
 fn process_initialize_confidential_transfer_fee_config(
     accounts: &[AccountInfo],

rust-toolchain.toml

@@ -1,2 +1,3 @@
 [toolchain]
 channel = "1.84.1"
+targets = ["wasm32-unknown-unknown"]

scripts/rust/build-wasm.mjs

@@ -0,0 +1,10 @@
+#!/usr/bin/env zx
+import 'zx/globals';
+import {
+  cliArguments,
+  workingDirectory,
+} from '../utils.mjs';
+
+const [folder, ...args] = cliArguments();
+const manifestPath = path.join(workingDirectory, folder, 'Cargo.toml');
+await $`cargo build --target wasm32-unknown-unknown --manifest-path ${manifestPath} ${args}`;