hmac-sha2-512
hmac-sha1
hmac-sha1-96
```

### Certificate-based authentication

`--sftp=trusted-user-ca-key=...` specifies a file containing public key of certificate authority that is trusted
to sign user certificates for authentication.

Implementation is identical with "TrustedUserCAKeys" setting in OpenSSH server with exception that only one CA
key can be defined.

  @Throws(SSLPeerUnverifiedException::class)
  @SuppressSignatureCheck
  override fun clean(
    chain: List<Certificate>,
    hostname: String,
  ): List<Certificate> {
    val certificates = (chain as List<X509Certificate>).toTypedArray()
    try {
      return x509TrustManagerExtensions.checkServerTrusted(certificates, "RSA", hostname)
    } catch (ce: CertificateException) {

    public void test_init_withInvalidSSLCertificate() {
        // Create a temporary invalid certificate file
        File invalidCertFile = null;
        try {
            invalidCertFile = File.createTempFile("invalid_cert", ".crt");
            try (FileWriter writer = new FileWriter(invalidCertFile)) {
                writer.write("INVALID CERTIFICATE CONTENT");
            }

        peerCertificates = listOf(serverCertificate.certificate, serverIntermediate.certificate),
        localCertificates = listOf(),
      )

    assertThat(handshake.tlsVersion).isEqualTo(TlsVersion.TLS_1_3)
    assertThat(handshake.cipherSuite).isEqualTo(CipherSuite.TLS_AES_128_GCM_SHA256)
    assertThat(handshake.peerCertificates).containsExactly(
      serverCertificate.certificate,
      serverIntermediate.certificate,
    )

	}

	cert, ok := clientKey.(*ssh.Certificate)
	if !ok {
		return errSftpPublicKeyWithoutCert
	}

	// ssh.CheckCert called by ssh.Authenticate accepts certificates
	// with empty principles list so we block those in here.
	if len(cert.ValidPrincipals) == 0 {
		return errSftpCertWithoutPrincipals
	}

	// Verify that certificate provided by user is issued by trusted CA,

    ```

    Get these strings with `HeldCertificate.certificatePem()` and `privateKeyPkcs8Pem()`.

 *  Fix: Handshake now returns peer certificates in canonical order: each certificate is signed by
    the certificate that follows and the last certificate is signed by a trusted root.

 *  Fix: Don't lose HTTP/2 flow control bytes when incoming data races with a stream close. If this

        .build()

    client.newCall(request).execute().use { response ->
      if (!response.isSuccessful) throw IOException("Unexpected code $response")

      for (certificate in response.handshake!!.peerCertificates) {
        println(CertificatePinner.pin(certificate))
      }
    }
  }
}

fun main() {
  CertificatePinning().run()

		Code:           "InvalidClientCertificate",
		Description:    "The provided client certificate is invalid. Retry with a different certificate.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrSTSTooManyIntermediateCAs: {
		Code:           "TooManyIntermediateCAs",
		Description:    "The provided client certificate contains too many intermediate CA certificates",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrSTSNotInitialized: {

              "emyPxgcYxn/eR44/KJ4EBs+lVDR3veyJm+kXQ99b21/+jh5Xos1AnX5iItreGCc=\n" +
              "-----END CERTIFICATE-----";

      CertificateFactory cf = CertificateFactory.getInstance("X.509");
      Certificate isgCertificate = cf.generateCertificate(new ByteArrayInputStream(isgCert.getBytes("UTF-8")));

      HandshakeCertificates certificates = new HandshakeCertificates.Builder()
              .addTrustedCertificate((X509Certificate) isgCertificate)

    assertThat(listOf(clientCertificate.certificate, clientIntermediate.certificate))
      .isEqualTo(serverHandshake.peerCertificates)
    assertThat(listOf(serverCertificate.certificate, serverIntermediate.certificate))
      .isEqualTo(serverHandshake.localCertificates)
    val clientHandshake = clientHandshakeFuture.get()
    assertThat(listOf(serverCertificate.certificate, serverIntermediate.certificate))