diff --git a/src/app/_helpers/custom-error-state-matcher.spec.ts b/src/app/_helpers/custom-error-state-matcher.spec.ts
new file mode 100644
index 0000000..7a3b76c
--- /dev/null
+++ b/src/app/_helpers/custom-error-state-matcher.spec.ts
@@ -0,0 +1,7 @@
+import { CustomErrorStateMatcher } from './custom-error-state-matcher';
+
+describe('CustomErrorStateMatcher', () => {
+  it('should create an instance', () => {
+    expect(new CustomErrorStateMatcher()).toBeTruthy();
+  });
+});
diff --git a/src/app/_helpers/custom-error-state-matcher.ts b/src/app/_helpers/custom-error-state-matcher.ts
new file mode 100644
index 0000000..8728100
--- /dev/null
+++ b/src/app/_helpers/custom-error-state-matcher.ts
@@ -0,0 +1,9 @@
+import {ErrorStateMatcher} from '@angular/material/core';
+import {FormControl, FormGroupDirective, NgForm} from '@angular/forms';
+
+export class CustomErrorStateMatcher implements ErrorStateMatcher{
+  isErrorState(control: FormControl | null, form: FormGroupDirective | NgForm | null): boolean {
+    const isSubmitted = form && form.submitted;
+    return !!(control && control.invalid && (control.dirty || control.touched || isSubmitted));
+  }
+}
diff --git a/src/app/_helpers/custom.validator.spec.ts b/src/app/_helpers/custom.validator.spec.ts
new file mode 100644
index 0000000..565ab9c
--- /dev/null
+++ b/src/app/_helpers/custom.validator.spec.ts
@@ -0,0 +1,7 @@
+import { Custom.Validator } from './custom.validator';
+
+describe('Custom.Validator', () => {
+  it('should create an instance', () => {
+    expect(new Custom.Validator()).toBeTruthy();
+  });
+});
diff --git a/src/app/_helpers/custom.validator.ts b/src/app/_helpers/custom.validator.ts
new file mode 100644
index 0000000..25aa06a
--- /dev/null
+++ b/src/app/_helpers/custom.validator.ts
@@ -0,0 +1,22 @@
+import {AbstractControl, ValidationErrors} from '@angular/forms';
+
+export class CustomValidator {
+  static passwordMatchValidator(control: AbstractControl): void {
+    const password: string = control.get('password').value;
+    const confirmPassword: string = control.get('confirmPassword').value;
+    if (password !== confirmPassword) {
+      control.get('confirmPassword').setErrors({ NoPasswordMatch: true });
+    }
+  }
+
+  static patternValidator(regex: RegExp, error: ValidationErrors): ValidationErrors | null {
+    return (control: AbstractControl): { [key: string]: any } => {
+      if (!control.value) {
+        return null;
+      }
+
+      const valid = regex.test(control.value);
+      return valid ? null : error;
+    };
+  }
+}
diff --git a/src/app/_helpers/error.interceptor.spec.ts b/src/app/_helpers/error.interceptor.spec.ts
new file mode 100644
index 0000000..4d083ad
--- /dev/null
+++ b/src/app/_helpers/error.interceptor.spec.ts
@@ -0,0 +1,16 @@
+import { TestBed } from '@angular/core/testing';
+
+import { ErrorInterceptor } from './error.interceptor';
+
+describe('ErrorInterceptor', () => {
+  beforeEach(() => TestBed.configureTestingModule({
+    providers: [
+      ErrorInterceptor
+      ]
+  }));
+
+  it('should be created', () => {
+    const interceptor: ErrorInterceptor = TestBed.inject(ErrorInterceptor);
+    expect(interceptor).toBeTruthy();
+  });
+});
diff --git a/src/app/_helpers/error.interceptor.ts b/src/app/_helpers/error.interceptor.ts
new file mode 100644
index 0000000..4b1511e
--- /dev/null
+++ b/src/app/_helpers/error.interceptor.ts
@@ -0,0 +1,25 @@
+import { Injectable } from '@angular/core';
+import {
+  HttpRequest,
+  HttpHandler,
+  HttpEvent,
+  HttpInterceptor
+} from '@angular/common/http';
+import {Observable, throwError} from 'rxjs';
+import {catchError} from 'rxjs/operators';
+
+@Injectable()
+export class ErrorInterceptor implements HttpInterceptor {
+
+  constructor() {}
+
+  intercept(request: HttpRequest<unknown>, next: HttpHandler): Observable<HttpEvent<unknown>> {
+    return next.handle(request).pipe(catchError(err => {
+      if ([401, 403].indexOf(err.status) !== -1) {
+        location.reload(true);
+      }
+      const error = err.error.message || err.statusText;
+      return throwError(error);
+    }));
+  }
+}
diff --git a/src/app/_helpers/index.ts b/src/app/_helpers/index.ts
new file mode 100644
index 0000000..1c31d75
--- /dev/null
+++ b/src/app/_helpers/index.ts
@@ -0,0 +1,4 @@
+export * from './custom.validator';
+export * from './error.interceptor';
+export * from './custom-error-state-matcher';
+export * from './unsafe-key-store';
diff --git a/src/app/_helpers/unsafe-key-store.spec.ts b/src/app/_helpers/unsafe-key-store.spec.ts
new file mode 100644
index 0000000..56785ce
--- /dev/null
+++ b/src/app/_helpers/unsafe-key-store.spec.ts
@@ -0,0 +1,7 @@
+import { UnsafeKeyStore } from './unsafe-key-store';
+
+describe('UnsafeKeyStore', () => {
+  it('should create an instance', () => {
+    expect(new UnsafeKeyStore()).toBeTruthy();
+  });
+});
diff --git a/src/app/_helpers/unsafe-key-store.ts b/src/app/_helpers/unsafe-key-store.ts
new file mode 100644
index 0000000..b4a65d9
--- /dev/null
+++ b/src/app/_helpers/unsafe-key-store.ts
@@ -0,0 +1,32 @@
+import * as openpgp from '../../assets/js/openpgp.min.js';
+
+export function UnsafeKeyStore(): void {
+  this.key = undefined;
+}
+
+UnsafeKeyStore.prototype.set = async function(privateKeyArmored): Promise<void> {
+  this.key = (await openpgp.key.readArmored(privateKeyArmored)).keys[0];
+  console.log('set pgp key', this.key.getKeyId().toHex());
+};
+
+UnsafeKeyStore.prototype.fingerprint = function(): any {
+  return this.key.keyPacket.fingerprint;
+};
+
+UnsafeKeyStore.prototype.keyid = function(): any {
+  return this.key.getKeyId();
+};
+
+UnsafeKeyStore.prototype.sign = async function(plainText): Promise<any> {
+  if (!this.key.isDecrypted()) {
+    const password = window.prompt('password');
+    await this.key.decrypt(password);
+  }
+  const opts = {
+    message: openpgp.message.fromText(plainText),
+    privateKeys: [this.key],
+    detached: true,
+  };
+  const signatureObject = await openpgp.sign(opts);
+  return signatureObject.signature;
+};