refactor(sdk-coin-sol): extract zk program id constant and tidy builder

Author: Copilot

modules/sdk-coin-sol/src/lib/confidentialMintBuilder.ts

@@ -195,7 +195,8 @@ export class ConfidentialMintBuilder extends TransactionBuilder {
     if (this._mintParams) {
       const params = this._mintParams;
       const recordOwner = params.recordAccountOwnerAddress || params.contextStateAuthorityAddress;
-      const space = Buffer.from(params.rangeRecordData, 'hex').length;
+      const rangeRecordBytes = Buffer.from(params.rangeRecordData, 'hex');
+      const space = rangeRecordBytes.length;
 
       instructions.push({
         type: InstructionBuilderTypes.CreateRecordAccount,
@@ -223,7 +224,7 @@ export class ConfidentialMintBuilder extends TransactionBuilder {
           params: {
             recordAccountAddress: params.rangeRecordAddress,
             recordAccountOwnerAddress: recordOwner,
-            offset: Buffer.from(params.rangeRecordData, 'hex').length,
+            offset: rangeRecordBytes.length,
             data: params.rangeRecordDataPart2,
           },
         });
@@ -247,6 +248,8 @@ export class ConfidentialMintBuilder extends TransactionBuilder {
         },
       });
 
+      // The range proof context state is stored in the same reusable record account used for the
+      // proof data; the equality/validity proofs each have their own one-shot context state account.
       instructions.push({
         type: InstructionBuilderTypes.VerifyRangeProof,
         params: {

modules/sdk-coin-sol/src/lib/constants.ts

@@ -38,6 +38,9 @@ export const JITO_MANAGER_FEE_ACCOUNT_TESTNET = 'DH7tmjoQ5zjqcgfYJU22JqmXhP5EY1t
 /** Solana Instructions sysvar address. Used by Token-2022 extension instructions that verify proofs in-tx. */
 export const INSTRUCTIONS_SYSVAR_ADDRESS = 'Sysvar1nstructions1111111111111111111111111';
 
+/** Solana zk-elgamal-proof program address. */
+export const ZK_ELGAMAL_PROOF_PROGRAM_ID = 'ZkE1G11tXDEfKBqrPK5G1iFbnW4mdeQTw48MYUb9Gkp';
+
 // Sdk instructions, mainly to check decoded types.
 export enum ValidInstructionTypesEnum {
   AdvanceNonceAccount = 'AdvanceNonceAccount',

modules/sdk-coin-sol/src/lib/solInstructionFactory.ts

@@ -27,7 +27,12 @@ import {
 import assert from 'assert';
 import BigNumber from 'bignumber.js';
 import { struct, u8, blob } from '@solana/buffer-layout';
-import { INSTRUCTIONS_SYSVAR_ADDRESS, InstructionBuilderTypes, MEMO_PROGRAM_PK } from './constants';
+import {
+  INSTRUCTIONS_SYSVAR_ADDRESS,
+  InstructionBuilderTypes,
+  MEMO_PROGRAM_PK,
+  ZK_ELGAMAL_PROOF_PROGRAM_ID,
+} from './constants';
 import {
   AtaClose,
   AtaInit,
@@ -774,7 +779,6 @@ const CONFIDENTIAL_MINT_BURN_EXTENSION_DISCRIMINATOR = 3;
 /**
  * Discriminators for the zk-elgamal-proof program verification instructions.
  */
-const ZK_ELGAMAL_PROOF_PROGRAM_ID = 'ZkE1G11tXDEfKBqrPK5G1iFbnW4mdeQTw48MYUb9Gkp';
 const VERIFY_CIPHERTEXT_COMMITMENT_EQUALITY_DISCRIMINATOR = 3;
 const VERIFY_BATCHED_GROUPED_CIPHERTEXT_3_HANDLES_VALIDITY_DISCRIMINATOR = 12;
 const VERIFY_BATCHED_RANGE_PROOF_U128_DISCRIMINATOR = 7;

modules/sdk-coin-sol/test/unit/transactionBuilder/confidentialMintBuilder.ts

@@ -21,8 +21,8 @@ describe('Sol Confidential Mint Builder', () => {
   const validityContextStateAddress = '7Uxci7Cyi3M6utvAFP6uhzkH3yMzhfqshA4Uu4hqBfy8';
   const contextStateAuthorityAddress = authAccount.pub;
 
-  const hex36 = '00'.repeat(36);
-  const hex64 = '00'.repeat(64);
+  const zeroBytes36 = '00'.repeat(36);
+  const zeroBytes64 = '00'.repeat(64);
   const rangeProofHex = '00'.repeat(1000);
 
   const confidentialMintBuilder = () => {
@@ -39,7 +39,7 @@ describe('Sol Confidential Mint Builder', () => {
         tokenAddress,
         mintAddress,
         authorityAddress,
-        decryptableZeroBalance: hex36,
+        decryptableZeroBalance: zeroBytes36,
         maximumPendingBalanceCreditCounter: '2',
         proofInstructionOffset: 0,
       });
@@ -51,7 +51,7 @@ describe('Sol Confidential Mint Builder', () => {
       instruction.data.length.should.equal(47);
       instruction.data[0].should.equal(27); // ConfidentialTransferExtension discriminator
       instruction.data[1].should.equal(2); // ConfigureConfidentialTransferAccount extension discriminator
-      instruction.data.slice(2, 38).toString('hex').should.equal(hex36);
+      instruction.data.slice(2, 38).toString('hex').should.equal(zeroBytes36);
       instruction.data.readBigUInt64LE(38).toString().should.equal('2');
       instruction.data[46].should.equal(0);
 
@@ -72,9 +72,9 @@ describe('Sol Confidential Mint Builder', () => {
         equalityContextStateAddress,
         validityContextStateAddress,
         contextStateAuthorityAddress,
-        newDecryptableSupply: hex36,
-        mintAmountAuditorCiphertextLo: hex64,
-        mintAmountAuditorCiphertextHi: hex64,
+        newDecryptableSupply: zeroBytes36,
+        mintAmountAuditorCiphertextLo: zeroBytes64,
+        mintAmountAuditorCiphertextHi: zeroBytes64,
         rangeRecordData: rangeProofHex,
       });
       const tx = await txBuilder.build();
@@ -99,9 +99,9 @@ describe('Sol Confidential Mint Builder', () => {
       confidentialMintInstruction.data.length.should.equal(169);
       confidentialMintInstruction.data[0].should.equal(42); // ConfidentialMint discriminator
       confidentialMintInstruction.data[1].should.equal(3); // confidentialMintBurn extension discriminator
-      confidentialMintInstruction.data.slice(2, 38).toString('hex').should.equal(hex36);
-      confidentialMintInstruction.data.slice(38, 102).toString('hex').should.equal(hex64);
-      confidentialMintInstruction.data.slice(102, 166).toString('hex').should.equal(hex64);
+      confidentialMintInstruction.data.slice(2, 38).toString('hex').should.equal(zeroBytes36);
+      confidentialMintInstruction.data.slice(38, 102).toString('hex').should.equal(zeroBytes64);
+      confidentialMintInstruction.data.slice(102, 166).toString('hex').should.equal(zeroBytes64);
       confidentialMintInstruction.data[166].should.equal(5);
       confidentialMintInstruction.data[167].should.equal(4);
       confidentialMintInstruction.data[168].should.equal(3);
@@ -120,9 +120,9 @@ describe('Sol Confidential Mint Builder', () => {
         equalityContextStateAddress,
         validityContextStateAddress,
         contextStateAuthorityAddress,
-        newDecryptableSupply: hex36,
-        mintAmountAuditorCiphertextLo: hex64,
-        mintAmountAuditorCiphertextHi: hex64,
+        newDecryptableSupply: zeroBytes36,
+        mintAmountAuditorCiphertextLo: zeroBytes64,
+        mintAmountAuditorCiphertextHi: zeroBytes64,
         rangeRecordData: part1,
         rangeRecordDataPart2: part2,
         closeRecordAccount: true,
@@ -153,7 +153,7 @@ describe('Sol Confidential Mint Builder', () => {
         tokenAddress,
         mintAddress,
         authorityAddress,
-        decryptableZeroBalance: hex36,
+        decryptableZeroBalance: zeroBytes36,
         maximumPendingBalanceCreditCounter: '65536',
       });
       txBuilder.confidentialMint({
@@ -165,9 +165,9 @@ describe('Sol Confidential Mint Builder', () => {
         equalityContextStateAddress,
         validityContextStateAddress,
         contextStateAuthorityAddress,
-        newDecryptableSupply: hex36,
-        mintAmountAuditorCiphertextLo: hex64,
-        mintAmountAuditorCiphertextHi: hex64,
+        newDecryptableSupply: zeroBytes36,
+        mintAmountAuditorCiphertextLo: zeroBytes64,
+        mintAmountAuditorCiphertextHi: zeroBytes64,
         rangeRecordData: rangeProofHex,
       });
       const tx = await txBuilder.build();
@@ -188,9 +188,9 @@ describe('Sol Confidential Mint Builder', () => {
         equalityContextStateAddress,
         validityContextStateAddress,
         contextStateAuthorityAddress,
-        newDecryptableSupply: hex36,
-        mintAmountAuditorCiphertextLo: hex64,
-        mintAmountAuditorCiphertextHi: hex64,
+        newDecryptableSupply: zeroBytes36,
+        mintAmountAuditorCiphertextLo: zeroBytes64,
+        mintAmountAuditorCiphertextHi: zeroBytes64,
         rangeRecordData: '00'.repeat(64),
       });
       const tx = await txBuilder.build();
@@ -211,9 +211,9 @@ describe('Sol Confidential Mint Builder', () => {
         equalityContextStateAddress,
         validityContextStateAddress,
         contextStateAuthorityAddress,
-        newDecryptableSupply: hex36,
-        mintAmountAuditorCiphertextLo: hex64,
-        mintAmountAuditorCiphertextHi: hex64,
+        newDecryptableSupply: zeroBytes36,
+        mintAmountAuditorCiphertextLo: zeroBytes64,
+        mintAmountAuditorCiphertextHi: zeroBytes64,
         rangeRecordData: rangeProofHex,
       });
       const tx = await txBuilder.build();
@@ -245,9 +245,9 @@ describe('Sol Confidential Mint Builder', () => {
           equalityContextStateAddress,
           validityContextStateAddress,
           contextStateAuthorityAddress,
-          newDecryptableSupply: hex36,
-          mintAmountAuditorCiphertextLo: hex64,
-          mintAmountAuditorCiphertextHi: hex64,
+          newDecryptableSupply: zeroBytes36,
+          mintAmountAuditorCiphertextLo: zeroBytes64,
+          mintAmountAuditorCiphertextHi: zeroBytes64,
           rangeRecordData: rangeProofHex,
         })
       ).throwError(/Invalid or missing tokenAddress/);