" supported protocols=${sslSocket.enabledProtocols!!.contentToString()}",
      )
  }

  /**
   * Returns a copy of this connection with the next connection spec to try, or null if no other
   * compatible connection specs are available.
   */
  internal fun nextConnectionSpec(
    connectionSpecs: List<ConnectionSpec>,
    sslSocket: SSLSocket,
  ): ConnectPlan? {

Specific security vs. connectivity decisions are implemented by [ConnectionSpec](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-connection-spec/). OkHttp includes four built-in connection specs:

 * `RESTRICTED_TLS` is a secure configuration, intended to meet stricter compliance requirements.
 * `MODERN_TLS` is a secure configuration that connects to modern HTTPS servers.

import assertk.assertions.isEqualTo
import assertk.assertions.isNull
import assertk.assertions.matches
import java.math.BigInteger
import java.security.KeyFactory
import java.security.spec.PKCS8EncodedKeySpec
import java.security.spec.X509EncodedKeySpec
import java.util.concurrent.TimeUnit
import okhttp3.testing.PlatformRule
import okhttp3.tls.HeldCertificate.Companion.decode
import okio.ByteString.Companion.decodeBase64

    // we rule out characters that would cause problems in host headers.
    if (c <= '\u001f' || c >= '\u007f') {
      return true
    }
    // Check for the characters mentioned in the WHATWG Host parsing spec:
    // U+0000, U+0009, U+000A, U+000D, U+0020, "#", "%", "/", ":", "?", "@", "[", "\", and "]"
    // (excluding the characters covered above).
    if (" #%/:?@[\\]".indexOf(c) != -1) {
      return true
    }
  }

    memory if web socket compression is negotiated but not used.


## Version 4.5.0-RC1

_2020-03-17_

**This release candidate turns on web socket compression.**

The [spec][rfc_7692] includes a sophisticated mechanism for client and server to negotiate
compression features. We strive to offer great performance in our default configuration and so we're

import java.security.Signature
import java.security.cert.X509Certificate
import java.security.interfaces.ECPublicKey
import java.security.interfaces.RSAPrivateKey
import java.security.interfaces.RSAPublicKey
import java.security.spec.PKCS8EncodedKeySpec
import java.util.UUID
import java.util.concurrent.TimeUnit
import okhttp3.internal.canParseAsIpAddress
import okhttp3.tls.internal.der.AlgorithmIdentifier

  private val algorithmParameters: DerAdapter<Any?> =
    Adapters.usingTypeHint { typeHint ->
      when (typeHint) {
        // This type is pretty strange. The spec says that for certain algorithms we must encode null
        // when it is present, and for others we must omit it!
        // https://tools.ietf.org/html/rfc4055#section-2.1

http://%ef%b7%90zyx.com

# Test name prepping, fullwidth input should be converted to ASCII and NOT
# IDN-ized. This is "Go" in fullwidth UTF-8/UTF-16.
http://\uff27\uff4f.com  s:http p:/ h:go.com

# URL spec forbids the following.
# https://www.w3.org/Bugs/Public/show_bug.cgi?id=24257
http://\uff05\uff14\uff11.com
http://%ef%bc%85%ef%bc%94%ef%bc%91.com

# ...%00 in fullwidth should fail (also as escaped UTF-8 input)

        return buildRedirectRequest(userResponse, method)
      }

      HTTP_CLIENT_TIMEOUT -> {
        // 408's are rare in practice, but some servers like HAProxy use this response code. The
        // spec says that we may repeat the request without modifications. Modern browsers also
        // repeat the request (even non-idempotent ones.)
        if (!client.retryOnConnectionFailure) {

    for each. This changes `Address` to no longer use `ConnectionSpec`. (This is
    an incompatible API change).

 *  **`FormEncodingBuilder` now uses `%20` instead of `+` for encoded spaces.**
    Both are permitted-by-spec, but `%20` requires fewer special cases.

 *  **Okio has been updated to 1.4.0.**
     ```xml
     <dependency>
       <groupId>com.squareup.okio</groupId>
       <artifactId>okio</artifactId>