From 167c053b8c5c9205fb08b54eb30cc1510b17f38d Mon Sep 17 00:00:00 2001
From: lmdulz <luca.dulz@med.uni-heidelberg.de>
Date: Thu, 18 Jan 2024 10:23:27 +0000
Subject: [PATCH] use callbacks from crypto in browser

---
 src/anonymizer.ts   | 16 +++++++++-------
 src/randomizer.ts   | 41 ++++++++++++++++++++++++++++++-----------
 src/uianonymizer.ts |  6 +++++-
 tsconfig.json       |  2 +-
 4 files changed, 45 insertions(+), 20 deletions(-)

diff --git a/src/anonymizer.ts b/src/anonymizer.ts
index b31819a..4eb72d4 100644
--- a/src/anonymizer.ts
+++ b/src/anonymizer.ts
@@ -42,13 +42,15 @@ export class Anonymizer {
       this.patientID = patientID;
     }
     this.randomizer = new Randomizer(seed);
-    this.dateOffsetHours = Number(
-      -(
-        (this.randomizer.toInt("dateOffset") %
-          (BigInt(maximumOffsetHours) - BigInt(minimumOffsetHours))) +
-        BigInt(minimumOffsetHours)
-      )
-    );
+    this.dateOffsetHours = Number(0);
+    this.randomizer.toInt("dateOffset", (res) => {
+      this.dateOffsetHours = Number(
+        -(
+          (res % (BigInt(maximumOffsetHours) - BigInt(minimumOffsetHours))) +
+          BigInt(minimumOffsetHours)
+        )
+      );
+    });
     //this.data = data;
     this.addressAnonymizer = new AddressAnonymizer(this.randomizer);
     this.elementHandlers = [
diff --git a/src/randomizer.ts b/src/randomizer.ts
index fc604c1..2c7bfe8 100644
--- a/src/randomizer.ts
+++ b/src/randomizer.ts
@@ -1,4 +1,5 @@
 import * as crypto from "crypto";
+import { data } from "dcmjs";
 import getRandomValues from "get-random-values";
 
 // use only in node env
@@ -25,10 +26,14 @@ export class Randomizer {
   private calculateMD5Digest(data: Uint8Array): Uint8Array {
     const hash = crypto.createHash("md5");
     hash.update(data);
-
     return hash.digest();
   }
 
+  private async calculateMD5DigestWeb(data: Uint8Array): Promise<Uint8Array> {
+    const hashBuffer = await crypto.subtle.digest("MD5", data);
+    return new Uint8Array(hashBuffer);
+  }
+
   private calculateResult(hash: Uint8Array): bigint {
     let result = 0;
     for (const byte of hash) {
@@ -47,23 +52,37 @@ export class Randomizer {
     return seed;
   }
 
-  public toInt(originalValue: string): bigint {
+  public toInt(originalValue: string, callback: (result: bigint) => void): void {
     const message = this.seed + String(originalValue);
     const encoder = new TextEncoder();
     const encoded = encoder.encode(message);
-    const hashed = this.calculateMD5Digest(encoded);
-    return this.calculateResult(hashed);
+
+    if (typeof window !== "undefined") {
+      this.calculateMD5DigestWeb(encoded).then((hashBuffer) => {
+        const hashed = hashBuffer;
+        const result = this.calculateResult(hashed);
+        callback(result);
+      });
+    } else {
+      const hashed = this.calculateMD5Digest(encoded);
+      const result = this.calculateResult(hashed);
+      callback(result);
+    }
   }
 
   public getIntsFromRanges(originalValue: string, ...suprema: number[]): number[] {
-    let big_Int = this.toInt(originalValue);
-    const result: number[] = [];
-    for (const x of suprema) {
-      const s = BigInt(x);
-      result.push(Number(big_Int % s));
-      big_Int = big_Int / s;
-    }
+    let result: bigint | number[] = [];
+    this.toInt(originalValue, (res) => {
+      let bigNumber = res;
+      const arr: number[] = [];
+      for (const x of suprema) {
+        const s = BigInt(x);
+        arr.push(Number(bigNumber % s));
+        bigNumber = bigNumber / s;
+      }
 
+      result = arr;
+    });
     return result;
   }
 }
diff --git a/src/uianonymizer.ts b/src/uianonymizer.ts
index 256f6fb..da2fd3c 100644
--- a/src/uianonymizer.ts
+++ b/src/uianonymizer.ts
@@ -33,6 +33,10 @@ export class UIAnonymizer {
   };
 
   newUI(origUI: string) {
-    return `2.${BigInt(10 ** 39) + this.randomizer.toInt(origUI)}`;
+    let number4String = BigInt(0);
+    this.randomizer.toInt(origUI, (res) => {
+      number4String = res;
+    });
+    return `2.${BigInt(10 ** 39) + number4String}`;
   }
 }
diff --git a/tsconfig.json b/tsconfig.json
index c4e68df..358c07b 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -9,7 +9,7 @@
     "incremental": true,
     "inlineSources": false,
     "isolatedModules": true,
-    "lib": ["ES2021"],
+    "lib": ["ES2021", "dom"],
     "module": "ES2015",
     "moduleResolution": "node",
     "noEmit": true,