* for (Challenge challenge : response.challenges()) {
 *   // If this is preemptive auth, use a preemptive credential.
 *   if (challenge.scheme().equalsIgnoreCase("OkHttp-Preemptive")) {
 *     return response.request().newBuilder()
 *         .header("Proxy-Authorization", "secret")
 *         .build();
 *   }
 * }
 * return null; // Didn't find a preemptive auth scheme.
 * ```
 *
 * ## Reactive Authentication
 *

final Dispatcher dispatcher = new Dispatcher() {

    @Override
    public MockResponse dispatch (RecordedRequest request) throws InterruptedException {

        switch (request.getPath()) {
            case "/v1/login/auth/":
                return new MockResponse().setResponseCode(200);
            case "/v1/check/version/":
                return new MockResponse().setResponseCode(200).setBody("version=9");

import javax.net.ssl.KeyStoreBuilderParameters
import javax.net.ssl.SSLContext
import javax.net.ssl.X509ExtendedKeyManager
import javax.security.auth.callback.Callback
import javax.security.auth.callback.CallbackHandler
import javax.security.auth.callback.PasswordCallback
import javax.security.auth.callback.UnsupportedCallbackException
import okhttp3.OkHttpClient
import okhttp3.Request
import okhttp3.internal.SuppressSignatureCheck

package okhttp3

import java.nio.charset.Charset
import kotlin.text.Charsets.ISO_8859_1
import okio.ByteString.Companion.encode

/** Factory for HTTP authorization credentials. */
object Credentials {
  /** Returns an auth credential for the Basic scheme. */
  @JvmStatic @JvmOverloads
  fun basic(
    username: String,
    password: String,
    charset: Charset = ISO_8859_1,
  ): String {

            url.toUrl(),
            Authenticator.RequestorType.SERVER,
          )
        }

      if (auth != null) {
        val credentialHeader = if (proxyAuthorization) "Proxy-Authorization" else "Authorization"
        val credential =
          Credentials.basic(
            auth.userName,
            String(auth.password),
            challenge.charset,
          )
        return request.newBuilder()

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package okhttp3.internal.tls

import java.security.cert.X509Certificate
import javax.security.auth.x500.X500Principal

/** A simple index that of trusted root certificates that have been loaded into memory. */
class BasicTrustRootIndex(vararg caCerts: X509Certificate) : TrustRootIndex {

 */
class Challenge(
  /** Returns the authentication scheme, like `Basic`. */
  @get:JvmName("scheme") val scheme: String,
  authParams: Map<String?, String>,
) {
  /**
   * Returns the auth params, including [realm] and [charset] if present, but as
   * strings. The map's keys are lowercase and should be treated case-insensitively.
   */
  @get:JvmName("authParams")
  val authParams: Map<String?, String>