* Authenticates a user with the specified username and password against LDAP.
     *
     * @param username the username for authentication
     * @param password the password for authentication
     * @return an optional containing the authenticated user if successful, empty otherwise
     */
    public OptionalEntity<FessUser> login(final String username, final String password) {
        // Add defensive null/blank checks

        final String username = fessConfig.getFesenUsername();
        final String password = fessConfig.getFesenPassword();
        if (StringUtil.isNotBlank(username) && StringUtil.isNotBlank(password)) {
            final String value = username + ":" + password;
            final String basicAuth = "Basic " + java.util.Base64.getEncoder().encodeToString(value.getBytes(StandardCharsets.UTF_8));

                        throw new RuntimeException("Plain text passwords are disabled");
                    } else {
                        // plain text
                        final String password = a.getPassword();
                        this.lmHash = new byte[(password.length() + 1) * 2];
                        this.ntHash = new byte[0];
                        writeString(password, this.lmHash, 0);
                    }
                }

But first, let's check some small concepts.

## In a hurry? { #in-a-hurry }

If you don't care about any of these terms and you just need to add security with authentication based on username and password *right now*, skip to the next chapters.

## OAuth2 { #oauth2 }

OAuth2 is a specification that defines several ways to handle authentication and authorization.

        verifyNfold("012345", 8,
                new byte[] { (byte) 0xbe, (byte) 0x07, (byte) 0x26, (byte) 0x31, (byte) 0x27, (byte) 0x6b, (byte) 0x19, (byte) 0x55 });

        // 56-fold("password")
        verifyNfold("password", 7,
                new byte[] { (byte) 0x78, (byte) 0xa0, (byte) 0x7b, (byte) 0x6c, (byte) 0xaf, (byte) 0x85, (byte) 0xfa });

        // 64-fold("Rough Consensus, and Running Code")

from fastapi import FastAPI, Form

app = FastAPI()


@app.post("/login/")
async def login(username: str = Form(), password: str = Form()):

    public static final String MVN_CMD = "mvn";
    public static final String MVN_NAME = "Maven";

    public static final String MVNENC_CMD = "mvnenc";
    public static final String MVNENC_NAME = "Maven Password Encrypting Tool";

    public static final String MVNSHELL_CMD = "mvnsh";
    public static final String MVNSHELL_NAME = "Maven Shell Tool";

    public static final String MVNUP_CMD = "mvnup";

    go install github.com/microsoft/go-sqlcmd/cmd/sqlcmd@latest || true
    for query in \
      "IF DB_ID('gorm') IS NULL CREATE DATABASE gorm" \
      "IF SUSER_ID (N'gorm') IS NULL CREATE LOGIN gorm WITH PASSWORD = 'LoremIpsum86';" \
      "IF USER_ID (N'gorm') IS NULL CREATE USER gorm FROM LOGIN gorm; ALTER SERVER ROLE sysadmin ADD MEMBER [gorm];"
    do

        //      <protocol>http</protocol>
        //      <host>proxy.somewhere.com</host>
        //      <port>8080</port>
        //      <username>proxyuser</username>
        //      <password>somepassword</password>
        //      <nonProxyHosts>www.google.com|*.somewhere.com</nonProxyHosts>
        //    </proxy>
        //  </proxies>

        for (Proxy proxy : settings.getProxies()) {

import java.net.Authenticator
import java.net.PasswordAuthentication

class RecordingAuthenticator(
  private val authentication: PasswordAuthentication? =
    PasswordAuthentication(
      "username",
      "password".toCharArray(),
    ),
) : Authenticator() {
  val calls = mutableListOf<String>()

  override fun getPasswordAuthentication(): PasswordAuthentication? {
    calls.add(