org.apache.sshd.common.SshConstants Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.sshd.common;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.function.IntUnaryOperator;
import org.apache.sshd.common.util.GenericUtils;
import org.apache.sshd.common.util.logging.LoggingUtils;
/**
* This interface defines constants for the SSH protocol.
*
* @author Apache MINA SSHD Project
*/
public final class SshConstants {
public static final int DEFAULT_PORT = 22;
/** Converts non-positive port value to {@value #DEFAULT_PORT} */
public static final IntUnaryOperator TO_EFFECTIVE_PORT = port -> (port > 0) ? port : DEFAULT_PORT;
//
// SSH message identifiers
//
public static final byte SSH_MSG_DISCONNECT = 1;
public static final byte SSH_MSG_IGNORE = 2;
public static final byte SSH_MSG_UNIMPLEMENTED = 3;
public static final byte SSH_MSG_DEBUG = 4;
public static final byte SSH_MSG_SERVICE_REQUEST = 5;
public static final byte SSH_MSG_SERVICE_ACCEPT = 6;
public static final byte SSH_MSG_KEXINIT = 20;
public static final int MSG_KEX_COOKIE_SIZE = 16;
public static final byte SSH_MSG_NEWKEYS = 21;
public static final byte SSH_MSG_KEX_FIRST = 30;
public static final byte SSH_MSG_KEX_LAST = 49;
public static final byte SSH_MSG_KEXDH_INIT = 30;
public static final byte SSH_MSG_KEXDH_REPLY = 31;
public static final byte SSH_MSG_KEX_DH_GEX_REQUEST_OLD = 30;
public static final byte SSH_MSG_KEX_DH_GEX_GROUP = 31;
public static final byte SSH_MSG_KEX_DH_GEX_INIT = 32;
public static final byte SSH_MSG_KEX_DH_GEX_REPLY = 33;
public static final byte SSH_MSG_KEX_DH_GEX_REQUEST = 34;
public static final byte SSH_MSG_USERAUTH_REQUEST = 50;
public static final byte SSH_MSG_USERAUTH_FAILURE = 51;
public static final byte SSH_MSG_USERAUTH_SUCCESS = 52;
public static final byte SSH_MSG_USERAUTH_BANNER = 53;
public static final byte SSH_MSG_USERAUTH_INFO_REQUEST = 60;
public static final byte SSH_MSG_USERAUTH_INFO_RESPONSE = 61;
public static final byte SSH_MSG_USERAUTH_PK_OK = 60;
public static final byte SSH_MSG_USERAUTH_PASSWD_CHANGEREQ = 60;
public static final byte SSH_MSG_USERAUTH_GSSAPI_MIC = 66;
public static final byte SSH_MSG_GLOBAL_REQUEST = 80;
public static final byte SSH_MSG_REQUEST_SUCCESS = 81;
public static final byte SSH_MSG_REQUEST_FAILURE = 82;
public static final byte SSH_MSG_CHANNEL_OPEN = 90;
public static final byte SSH_MSG_CHANNEL_OPEN_CONFIRMATION = 91;
public static final byte SSH_MSG_CHANNEL_OPEN_FAILURE = 92;
public static final byte SSH_MSG_CHANNEL_WINDOW_ADJUST = 93;
public static final byte SSH_MSG_CHANNEL_DATA = 94;
public static final byte SSH_MSG_CHANNEL_EXTENDED_DATA = 95;
public static final byte SSH_MSG_CHANNEL_EOF = 96;
public static final byte SSH_MSG_CHANNEL_CLOSE = 97;
public static final byte SSH_MSG_CHANNEL_REQUEST = 98;
public static final byte SSH_MSG_CHANNEL_SUCCESS = 99;
public static final byte SSH_MSG_CHANNEL_FAILURE = 100;
//
// Disconnect error codes
//
public static final int SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT = 1;
public static final int SSH2_DISCONNECT_PROTOCOL_ERROR = 2;
public static final int SSH2_DISCONNECT_KEY_EXCHANGE_FAILED = 3;
public static final int SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED = 4;
public static final int SSH2_DISCONNECT_RESERVED = 4;
public static final int SSH2_DISCONNECT_MAC_ERROR = 5;
public static final int SSH2_DISCONNECT_COMPRESSION_ERROR = 6;
public static final int SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE = 7;
public static final int SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED = 8;
public static final int SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE = 9;
public static final int SSH2_DISCONNECT_CONNECTION_LOST = 10;
public static final int SSH2_DISCONNECT_BY_APPLICATION = 11;
public static final int SSH2_DISCONNECT_TOO_MANY_CONNECTIONS = 12;
public static final int SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER = 13;
public static final int SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE = 14;
public static final int SSH2_DISCONNECT_ILLEGAL_USER_NAME = 15;
//
// Open error codes
//
public static final int SSH_OPEN_ADMINISTRATIVELY_PROHIBITED = 1;
public static final int SSH_OPEN_CONNECT_FAILED = 2;
public static final int SSH_OPEN_UNKNOWN_CHANNEL_TYPE = 3;
public static final int SSH_OPEN_RESOURCE_SHORTAGE = 4;
// Some more constants
public static final int SSH_EXTENDED_DATA_STDERR = 1; // see RFC4254 section 5.2
// 32-bit length + 8-bit pad length
public static final int SSH_PACKET_HEADER_LEN = Integer.BYTES + Byte.BYTES;
/*
* See https://tools.ietf.org/html/rfc4253#section-6.1:
*
* All implementations MUST be able to process packets with an uncompressed payload length of 32768 bytes or less
* and a total packet size of 35000 bytes or less
*/
public static final int SSH_REQUIRED_PAYLOAD_PACKET_LENGTH_SUPPORT = 32768;
public static final int SSH_REQUIRED_TOTAL_PACKET_LENGTH_SUPPORT = 35000;
private SshConstants() {
throw new UnsupportedOperationException("No instance allowed");
}
private static final class LazyAmbiguousOpcodesHolder {
private static final Set AMBIGUOUS_OPCODES = Collections.unmodifiableSet(
new HashSet<>(
LoggingUtils.getAmbiguousMenmonics(SshConstants.class, "SSH_MSG_").values()));
private LazyAmbiguousOpcodesHolder() {
throw new UnsupportedOperationException("No instance allowed");
}
}
/**
* @param cmd The command value
* @return {@code true} if this value is used by several different messages
* @see #getAmbiguousOpcodes()
*/
public static boolean isAmbiguousOpcode(int cmd) {
Collection ambiguousOpcodes = getAmbiguousOpcodes();
return ambiguousOpcodes.contains(cmd);
}
/**
* @return A {@link Set} of opcodes that are used by several different messages
*/
@SuppressWarnings("synthetic-access")
public static Set getAmbiguousOpcodes() {
return LazyAmbiguousOpcodesHolder.AMBIGUOUS_OPCODES;
}
private static final class LazyMessagesMapHolder {
private static final Map MESSAGES_MAP = LoggingUtils.generateMnemonicMap(SshConstants.class, f -> {
String name = f.getName();
if (!name.startsWith("SSH_MSG_")) {
return false;
}
try {
return !isAmbiguousOpcode(f.getByte(null));
} catch (Exception e) {
return false;
}
});
private LazyMessagesMapHolder() {
throw new UnsupportedOperationException("No instance allowed");
}
}
/**
* Converts a command value to a user-friendly name
*
* @param cmd The command value
* @return The user-friendly name - if not one of the defined {@code SSH_MSG_XXX} values then returns the string
* representation of the command's value
*/
public static String getCommandMessageName(int cmd) {
@SuppressWarnings("synthetic-access")
String name = LazyMessagesMapHolder.MESSAGES_MAP.get(cmd);
if (GenericUtils.isEmpty(name)) {
return Integer.toString(cmd);
} else {
return name;
}
}
private static final class LazyReasonsMapHolder {
private static final Map REASONS_MAP
= LoggingUtils.generateMnemonicMap(SshConstants.class, "SSH2_DISCONNECT_");
private LazyReasonsMapHolder() {
throw new UnsupportedOperationException("No instance allowed");
}
}
/**
* Converts a disconnect reason value to a user-friendly name
*
* @param reason The disconnect reason value
* @return The user-friendly name - if not one of the defined {@code SSH2_DISCONNECT_} values then returns
* the string representation of the reason's value
*/
public static String getDisconnectReasonName(int reason) {
@SuppressWarnings("synthetic-access")
String name = LazyReasonsMapHolder.REASONS_MAP.get(reason);
if (GenericUtils.isEmpty(name)) {
return Integer.toString(reason);
} else {
return name;
}
}
private static final class LazyOpenCodesMapHolder {
private static final Map OPEN_CODES_MAP
= LoggingUtils.generateMnemonicMap(SshConstants.class, "SSH_OPEN_");
private LazyOpenCodesMapHolder() {
throw new UnsupportedOperationException("No instance allowed");
}
}
/**
* Converts an open error value to a user-friendly name
*
* @param code The open error value
* @return The user-friendly name - if not one of the defined {@code SSH_OPEN_} values then returns the string
* representation of the reason's value
*/
public static String getOpenErrorCodeName(int code) {
@SuppressWarnings("synthetic-access")
String name = LazyOpenCodesMapHolder.OPEN_CODES_MAP.get(code);
if (GenericUtils.isEmpty(name)) {
return Integer.toString(code);
} else {
return name;
}
}
}