# Security - First Steps { #security-first-steps }

Let's imagine that you have your **backend** API in some domain.

And you have a **frontend** in another domain or in a different path of the same domain (or in a mobile application).

And you want to have a way for the frontend to authenticate with the backend, using a **username** and **password**.

We can use **OAuth2** to build that with **FastAPI**.

/**
 * @author koichik
 *
 */
public class FileUtilTest {

    URL url = ResourceUtil.getResource(getClass().getName().replace('.', '/') + ".txt");

    File inputFile = URLUtil.toFile(url);

    @Rule
    public TemporaryFolder tempFolder = new TemporaryFolder();

    /**
     * @throws Exception
     */
    @Test
    public void testFileToFile() throws Exception {

errors.app.db.already.updated = Başka bir işlem tarafından güncellenmiş olabilir. Lütfen tekrar deneyin.
errors.app.db.already.exists = Veri zaten mevcut. Lütfen tekrar deneyin.
errors.app.double.submit.request = Bu istekten önce işlenmiş olabilir. Lütfen tekrar deneyin.
# _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
# you can define your messages here:
# e.g.
# errors.xxx = ...

  static final RegularImmutableBiMap<Object, Object> EMPTY =
      new RegularImmutableBiMap<>(
          null, null, (Entry<Object, Object>[]) ImmutableMap.EMPTY_ENTRY_ARRAY, 0, 0);

  static final double MAX_LOAD_FACTOR = 1.2;

  private final transient @Nullable ImmutableMapEntry<K, V> @Nullable [] keyTable;
  private final transient @Nullable ImmutableMapEntry<K, V> @Nullable [] valueTable;

package cmd

import (
	"context"
	"maps"
	"math/rand"
	"sync"
	"time"

	"github.com/minio/madmin-go/v3"
)

//go:generate msgp -file=$GOFILE

// SiteResyncStatus captures current replication resync status for a target site
type SiteResyncStatus struct {
	Version int `json:"version" msg:"v"`
	// Overall site status

labels.user_postOfficeBox=Post Office Box
labels.postOfficeBox=Post Office Box
labels.user_initials=Initials
labels.initials=Initials
labels.user_carLicense=Car License
labels.carLicense=Car License
labels.user_mobile=Mobile
labels.mobile=Mobile
labels.user_postalAddress=Postal Address
labels.postalAddress=Postal Address
labels.user_city=City
labels.city=City
labels.user_teletexTerminalIdentifier=Teletex Terminal Identifier

        assertSame(response, out);
        verify(treeConnection).send(resourceLoc, request, response, params);
    }

    @Test
    @DisplayName("close calls release and decrements usage; double release throws")
    void closeAndReleaseBehavior() {
        // Validates usage counting and that an extra release() throws RuntimeCIFSException
        // First close -> usage 1 -> 0, triggers treeConnection.release()

Stellen wir uns vor, dass Sie Ihre **Backend**-API auf einer Domain haben.

Und Sie haben ein **Frontend** auf einer anderen Domain oder in einem anderen Pfad derselben Domain (oder in einer Mobile-Anwendung).

Und Sie möchten eine Möglichkeit haben, dass sich das Frontend mithilfe eines **Benutzernamens** und eines **Passworts** beim Backend authentisieren kann.

		{"a/b/c/", false},
		{"../../etc", false},
		{"../../", false},
		{"/../../etc", false},
		{" ../etc", false},
		{"./././", false},
		{"./etc", false},
		{`contains//double/forwardslash`, false},
		{`//contains/double-forwardslash-prefix`, false},
		{string([]byte{0xff, 0xfe, 0xfd}), false},
	}

	for i, testCase := range testCases {
		isValidObjectName := IsValidObjectName(testCase.objectName)

errors.app.db.already.updated = Pode ter sido atualizado por outro processo. Por favor, tente novamente.
errors.app.db.already.exists = Os dados já existem. Por favor, tente novamente.
errors.app.double.submit.request = Esta solicitação pode já ter sido processada. Por favor, tente novamente.
# _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
# you can define your messages here:
# e.g.