Implemented transaction verification check

src/app/units/rtdb/Transaction.ts

@@ -0,0 +1,65 @@
+import {FirebaseUnit} from "../FirebaseUnit"
+import {TransactionResource, TransactionResourceItem} from "../../rtdb/TransactionResource"
+import {Singleton, Inject} from "@extollo/di"
+import {Unit, Logging} from "@extollo/lib"
+import * as openpgp from "openpgp"
+/**
+ * Transaction Unit
+ * ---------------------------------------
+ * Put some description here.
+ */
+@Singleton()
+export class Transaction extends Unit {
+    @Inject()
+    protected readonly firebase!: FirebaseUnit
+
+    public async compareTransactions(transaction1: TransactionResourceItem, transaction2: TransactionResourceItem){
+        // verify signature
+        const result1 = await openpgp.verify({
+            publicKeys: await openpgp.readKey({
+                armoredKey: transaction2.partnerPublicKey
+            }),
+            message: openpgp.Message.fromText(transaction1.combinedHash),
+            signature: await openpgp.readSignature({
+                armoredSignature: transaction1.validationSignature // parse detached signature
+            })
+        })
+        const result2 = await openpgp.verify({
+            publicKeys: await openpgp.readKey({
+                armoredKey: transaction1.partnerPublicKey
+            }),
+            message: openpgp.Message.fromText(transaction2.combinedHash),
+            signature: await openpgp.readSignature({
+                armoredSignature: transaction2.validationSignature // parse detached signature
+            })
+        })
+        return await (result1.signatures[0].verified) && await (result2.signatures[0].verified);
+    }
+    
+    public async up() {
+        this.firebase.ref("transaction").on("value", async () => {
+            // array of pairs of tranaction resource items
+            const groupedTransactions: [TransactionResourceItem, TransactionResourceItem][] = []
+            // collection of transaction resource items
+            let transactions = await TransactionResource.collect().collect()
+            // compare each item
+            transactions.each(transaction1 => {
+                // for each item that is not itself
+                transactions.where("combinedHash", "!=", transaction1.combinedHash)
+                // get a second item
+                .each(transaction2 => {
+                    //if the item matches
+                    if (this.compareTransactions(transaction1, transaction2)) {
+                        // and remove the two matching items
+                        transactions = transactions.whereNotIn("combinedHash", [transaction1.combinedHash, transaction2.combinedHash])
+                        // insert grouped items into groupedTransactions
+                        groupedTransactions.push([transaction1, transaction2]);
+                    }
+                })
+            })
+        })
+    }
+    
+    public async down() {
+    }
+}