It is a project from the Linux Foundation. It provides **HTTPS certificates for free**, in an automated way. These certificates use all the standard cryptographic security, and are short-lived (about 3 months), so the **security is actually better** because of their reduced lifespan.

        // For now, return null as the GUID is typically provided in the request context
        // and the response doesn't necessarily contain the GUID in a standard format
        return null;
    }

import java.text.ParseException
import java.text.SimpleDateFormat
import java.util.Date
import java.util.TimeZone
import kotlin.reflect.KClass
import okio.ByteString

/**
 * Built-in adapters for reading standard ASN.1 types.
 */
internal object Adapters {
  val BOOLEAN =
    BasicDerAdapter(
      name = "BOOLEAN",
      tagClass = DerHeader.TAG_CLASS_UNIVERSAL,
      tag = 1L,
      codec =

Starlette (and **FastAPI**) are based on <a href="https://anyio.readthedocs.io/en/stable/" class="external-link" target="_blank">AnyIO</a>, which makes it compatible with both Python's standard library <a href="https://docs.python.org/3/library/asyncio-task.html" class="external-link" target="_blank">asyncio</a> and <a href="https://trio.readthedocs.io/en/stable/" class="external-link" target="_blank">Trio</a>.

    By doing it this way, we can put it in a `with` block, and that way, ensure that the file-like object is closed after finishing.

/// tip

Notice that here as we are using standard `open()` that doesn't support `async` and `await`, we declare the path operation with normal `def`.

///

### `FileResponse` { #fileresponse }

Asynchronously streams a file as the response.

	directoryHeaderSignature = 0x02014b50
	directoryEndSignature    = 0x06054b50
	directory64LocSignature  = 0x07064b50
	directory64EndSignature  = 0x06064b50
	dataDescriptorSignature  = 0x08074b50 // de-facto standard; required by OS X Finder
	fileHeaderLen            = 30         // + filename + extra
	directoryHeaderLen       = 46         // + filename + extra + comment
	directoryEndLen          = 22         // + comment

		if f == "" || len(f)%2 != 0 || strings.TrimLeft(f, "0123456789abcdef") != "" {
			return false
		}
	}
	return true
}

// It would be nice if the error messages always began with
// the standard file:line: prefix,
// but that's not where we are today.
// It might be at the beginning but it might be in the middle of the printed instruction.

  @InlineMe(replacement = "Boolean.hashCode(value)")
  public static int hashCode(boolean value) {
    return Boolean.hashCode(value);
  }

  /**
   * Compares the two specified {@code boolean} values in the standard way ({@code false} is
   * considered less than {@code true}). The sign of the value returned is the same as that of
   * {@code ((Boolean) a).compareTo(b)}.
   *

  @InlineMe(replacement = "Boolean.hashCode(value)")
  public static int hashCode(boolean value) {
    return Boolean.hashCode(value);
  }

  /**
   * Compares the two specified {@code boolean} values in the standard way ({@code false} is
   * considered less than {@code true}). The sign of the value returned is the same as that of
   * {@code ((Boolean) a).compareTo(b)}.
   *

///

For example, this custom validator checks that the item ID starts with `isbn-` for an <abbr title="ISBN means International Standard Book Number">ISBN</abbr> book number or with `imdb-` for an <abbr title="IMDB (Internet Movie Database) is a website with information about movies">IMDB</abbr> movie URL ID: