parse opreturn data correctly

block-core · Sep 20, 2022 · bce16fb · bce16fb
1 parent 5a435ac
commit bce16fb
Showing 1 changed file with 119 additions and 84 deletions.
diff --git a/src/Blockcore.Explorer/ClientApp/src/app/explorer/transaction/transaction.component.ts b/src/Blockcore.Explorer/ClientApp/src/app/explorer/transaction/transaction.component.ts
@@ -5,106 +5,141 @@ import { ApiService } from 'src/app/services/api.service';
 import { SetupService } from 'src/app/services/setup.service';
 
 @Component({
-  selector: 'app-transaction-component',
-  templateUrl: './transaction.component.html'
+   selector: 'app-transaction-component',
+   templateUrl: './transaction.component.html'
 })
 export class TransactionComponent implements OnInit, OnDestroy {
-  @HostBinding('class.content-centered-top') hostClass = true;
-
-  info: any;
-  node: any;
-  blockchain: any;
-  network: any;
-  configuration: any;
-  consensus: any;
-  peers: any;
-  blocks: any;
-  transactions: any;
-
-  timerInfo: any;
-  timerBlocks: any;
-  timerTransactions: any;
-  transaction: any;
-  detailsVisible = false;
-  lastBlockHeight: number;
-  subscription: any;
-  error: Error;
-
-  constructor(
-    private api: ApiService,
-    private router: Router,
-    public setup: SetupService,
-    private activatedRoute: ActivatedRoute) {
-
-    this.activatedRoute.paramMap.subscribe(async params => {
-      const id: any = params.get('transaction');
-      console.log('Transaction ID:', id);
-
-       try {
-        this.transaction = await this.api.getTransaction(id);
-
-         if (this.transaction.outputs.length == 2)
-         {
-            if (this.transaction.outputs[0].outputType == "OP_CALLCONTRACT")
-               this.transaction.hasContract = true;
-
-            if (this.transaction.outputs[0].outputType == "OP_CREATECONTRACT")
-               this.transaction.hasContract = true;
-
-            if (this.transaction.outputs[1].outputType == "OP_CALLCONTRACT")
-               this.transaction.hasContract = true;
-
-            if (this.transaction.outputs[1].outputType == "OP_CREATECONTRACT")
-               this.transaction.hasContract = true;
+   @HostBinding('class.content-centered-top') hostClass = true;
+
+   info: any;
+   node: any;
+   blockchain: any;
+   network: any;
+   configuration: any;
+   consensus: any;
+   peers: any;
+   blocks: any;
+   transactions: any;
+
+   timerInfo: any;
+   timerBlocks: any;
+   timerTransactions: any;
+   transaction: any;
+   detailsVisible = false;
+   lastBlockHeight: number;
+   subscription: any;
+   error: Error;
+
+   constructor(
+      private api: ApiService,
+      private router: Router,
+      public setup: SetupService,
+      private activatedRoute: ActivatedRoute) {
+
+      this.activatedRoute.paramMap.subscribe(async params => {
+         const id: any = params.get('transaction');
+         console.log('Transaction ID:', id);
+
+         try {
+            this.transaction = await this.api.getTransaction(id);
+
+            if (this.transaction.outputs.length == 2) {
+               if (this.transaction.outputs[0].outputType == "OP_CALLCONTRACT")
+                  this.transaction.hasContract = true;
+
+               if (this.transaction.outputs[0].outputType == "OP_CREATECONTRACT")
+                  this.transaction.hasContract = true;
+
+               if (this.transaction.outputs[1].outputType == "OP_CALLCONTRACT")
+                  this.transaction.hasContract = true;
+
+               if (this.transaction.outputs[1].outputType == "OP_CREATECONTRACT")
+                  this.transaction.hasContract = true;
+            }
+
+
+            this.error = null;
+         } catch (e) {
+            this.error = e;
          }
 
+         console.log(this.transaction);
+      });
+   }
 
-        this.error = null;
-      } catch (e) {
-        this.error = e;
-      }
 
-      console.log(this.transaction);
-    });
-  }
+   async ngOnInit() {
 
-
-  async ngOnInit() {
+   }
 
-  }
+   toggleDetails() {
+      this.detailsVisible = !this.detailsVisible;
+   }
 
-  toggleDetails() {
-    this.detailsVisible = !this.detailsVisible;
-  }
+   ngOnDestroy(): void {
 
-  ngOnDestroy(): void {
+   }
 
-  }
+   /** Parse the hex formatted script. Ref: https://en.bitcoin.it/wiki/Script */
+   parseOpreturn(data: any) {
+      if (!data) {
+         return null;
+      }
 
-  parseOpreturn(data) {
+      // First get the bytes from the complete hex value:
+      const buff = this.hexToBytes(data);// secp.utils.hexToBytes(data);
 
-   // the buffer of the OP_RETURN has the first 2 char for the opcode opreturn=6a 
-   // and the next 2 char for the pushdata opcode we sktip the first 4 chars 
-   const dataParsed = data.substring(4);
+      if (buff[0] != 106) {
+         throw new Error('Not OP_RETURN.');
+      }
 
-    const buffer =  Uint8Array.from(dataParsed).buffer;
-    //return this.hex2text(buffer);
-    return this.hex2a(dataParsed);
-}
+      const opcode = buff[1];
 
- hex2text(buffer) { // buffer is an ArrayBuffer
-  return [...new Uint8Array(buffer)]
-      .map(x => x.toString(16).padStart(2, '0'))
-      .join('');
-}
+      let skip = 2; // 1-75: The next opcode bytes is data to be pushed onto the stack
 
-hex2a(hexx) {
-  var hex = hexx.toString();//force conversion
-  var str = '';
-  for (var i = 0; i < hex.length; i += 2)
-      str += String.fromCharCode(parseInt(hex.substr(i, 2), 16));
-  return str;
-}
+      if (opcode == 76) {
+         // The next byte contains the number of bytes to be pushed onto the stack.
+         skip = 3;
+      } else if (opcode == 77) {
+         // The next two bytes contain the number of bytes to be pushed onto the stack in little endian order.
+         skip = 5;
+      } else if (opcode == 78) {
+         // The next four bytes contain the number of bytes to be pushed onto the stack in little endian order.
+         skip = 6;
+      }
+
+      // Skip the prefix for OP_RETURN:
+      const parsedBuff = buff.slice(skip, buff.length);
 
+      if (parsedBuff.length == 0) {
+         return null;
+      }
+
+      // First transform back to hex, but now only the payload data:
+      const dataHex = this.bytesToHex(parsedBuff);// secp.utils.bytesToHex(parsedBuff);
+
+      return this.hexToUtf8(dataHex);
+   }
+
+   hexToUtf8(hex: any) {
+      return decodeURIComponent('%' + hex.match(/.{1,2}/g).join('%'));
+   }
+
+   // Convert a hex string to a byte array
+   hexToBytes(hex) {
+      for (var bytes = [], c = 0; c < hex.length; c += 2)
+         bytes.push(parseInt(hex.substr(c, 2), 16));
+      return bytes;
+   }
+
+   // Convert a byte array to a hex string
+   bytesToHex(bytes) {
+      for (var hex = [], i = 0; i < bytes.length; i++) {
+         var current = bytes[i] < 0 ? bytes[i] + 256 : bytes[i];
+         hex.push((current >>> 4).toString(16));
+         hex.push((current & 0xF).toString(16));
+      }
+      return hex.join("");
+   }
 }