- Communication between the etcd server and kube-apiserver on master is now overridden to use HTTPS instead of HTTP when mTLS is enabled in GCE. ([#74690](https://github.com/kubernetes/kubernetes/pull/74690), [@wenjiaswe](https://github.com/wenjiaswe))

### GCP

- [stackdriver addon] Bumped prometheus-to-sd to v0.5.0 to pick up security fixes.

pkg crypto/tls, const TLS_ECDHE_ECDSA_WITH_RC4_128_SHA uint16
pkg crypto/tls, const TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 = 49199
pkg crypto/tls, const TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 uint16
pkg crypto/tls, const VersionSSL30 = 768
pkg crypto/tls, const VersionSSL30 ideal-int
pkg crypto/tls, const VersionTLS10 = 769
pkg crypto/tls, const VersionTLS10 ideal-int
pkg crypto/tls, const VersionTLS11 = 770

	public final fun authenticator ()Lokhttp3/Authenticator;
	public final fun cache ()Lokhttp3/Cache;
	public final fun callTimeoutMillis ()I
	public final fun certificateChainCleaner ()Lokhttp3/internal/tls/CertificateChainCleaner;
	public final fun certificatePinner ()Lokhttp3/CertificatePinner;
	public final fun connectTimeoutMillis ()I
	public final fun connectionPool ()Lokhttp3/ConnectionPool;

* Fix a race condition in which kubeadm only waits for the kubelets kubeconfig file when it has performed the TLS bootstrap, but wasn't waiting for certificates to be present in the filesystem ([#72030](https://github.com/kubernetes/kubernetes/pull/72030), [@ereslibre](https://github.com/ereslibre))

- github.com/markbates/pkger: [v0.17.1](https://github.com/markbates/pkger/tree/v0.17.1)
- github.com/marten-seemann/qtls: [v0.2.3](https://github.com/marten-seemann/qtls/tree/v0.2.3)
- github.com/mholt/certmagic: [6a42ef9](https://github.com/mholt/certmagic/tree/6a42ef9)
- github.com/naoina/go-stringutil: [v0.1.0](https://github.com/naoina/go-stringutil/tree/v0.1.0)

	baseTestCases := []TestSuiteCommon{
		// Init and run test on ErasureSD backend with signature v4.
		{serverType: "ErasureSD", signer: signerV4},
		// Init and run test on ErasureSD backend, with tls enabled.
		{serverType: "ErasureSD", signer: signerV4, secure: true},
		// Init and run test on Erasure backend.
		{serverType: "Erasure", signer: signerV4},
		// Init and run test on ErasureSet backend.

  Beta feature in 1.27. ([#114445](https://github.com/kubernetes/kubernetes/pull/114445), [@mengjiao-liu](https://github.com/mengjiao-liu))
- `Secret` of `kubernetes.io/tls` type now verifies that the private key matches the cert ([#113581](https://github.com/kubernetes/kubernetes/pull/113581), [@aimuz](https://github.com/aimuz))

pkg crypto/subtle, func XORBytes([]uint8, []uint8, []uint8) int #53021
pkg crypto/tls, method (*CertificateVerificationError) Error() string #48152
pkg crypto/tls, method (*CertificateVerificationError) Unwrap() error #48152
pkg crypto/tls, type CertificateVerificationError struct #48152
pkg crypto/tls, type CertificateVerificationError struct, Err error #48152
pkg crypto/tls, type CertificateVerificationError struct, UnverifiedCertificates []*x509.Certificate #48152

		}
		if creds.IsTemp() && !creds.IsExpired() {
			var parentPolicy string
			u, err := globalIAMSys.GetUserInfo(ctx, creds.ParentUser)
			if err != nil {
				// Parent may be "virtual" (for ldap, oidc, client tls auth,
				// custom auth plugin), so in such cases we apply no parent
				// policy. The session token will contain info about policy to
				// be applied.
				if !errors.Is(err, errNoSuchUser) {

- `client-go`, using log level 9, traces the following events of a HTTP request:
      - DNS lookup
      - TCP dialing
      - TLS handshake
      - Time to get a connection from the pool
      - Time to process a request ([#105156](https://github.com/kubernetes/kubernetes/pull/105156), [@aojea](https://github.com/aojea))

### Documentation