Package org.eclipse.jgit.internal.transport.ssh

Class OpenSshConfigFile

java.lang.Object

org.eclipse.jgit.internal.transport.ssh.OpenSshConfigFile

All Implemented Interfaces:

SshConfigStore

public class OpenSshConfigFile
extends java.lang.Object
implements SshConfigStore

Fairly complete configuration parser for the openssh ~/.ssh/config file.

Both JSch 0.1.54 and Apache MINA sshd 2.1.0 have parsers for this, but both are buggy. Therefore we implement our own parser to read an openssh configuration file.

Limitations compared to the full openssh 7.5 parser:

• This parser does not handle Match or Include keywords.
• This parser does not do host name canonicalization.

Note that openssh's readconf.c is a validating parser; this parser does not validate entries.

This config does %-substitutions for the following tokens:

• %% - single %
• %C - short-hand for %l%h%p%r.
• %d - home directory path
• %h - remote host name
• %L - local host name without domain
• %l - FQDN of the local host
• %n - host name as specified in lookup(String, int, String)
• %p - port number; if not given in lookup(String, int, String) replaced only if set in the config
• %r - remote user name; if not given in lookup(String, int, String) replaced only if set in the config
• %u - local user name

%i is not handled; Java has no concept of a "user ID". %T is always replaced by NONE.

See Also:

man ssh-config

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	OpenSshConfigFile.HostEntry	A host entry from the ssh config file.
private static class	OpenSshConfigFile.Replacer
private static class	OpenSshConfigFile.State	Encapsulates entries read out of the configuration file, and a cache of fully resolved entries created from that.

Nested classes/interfaces inherited from interface org.eclipse.jgit.transport.SshConfigStore

SshConfigStore.HostConfig

Field Summary

Fields

Modifier and Type	Field	Description
private java.io.File	configFile	The .ssh/config file we read and monitor for updates.
private java.io.File	home	The user's home directory, as key files may be relative to here.
private java.time.Instant	lastModified	Modification time of configFile when it was last loaded.
private java.lang.String	localUserName	User name of the user on the host OS.
private OpenSshConfigFile.State	state	State read from the config file, plus the cache.

Fields inherited from interface org.eclipse.jgit.transport.SshConfigStore

EMPTY_CONFIG

Constructor Summary

Constructors

Constructor	Description
OpenSshConfigFile(java.io.File home, java.io.File config, java.lang.String localUserName)	Creates a new OpenSshConfigFile that will read the config from file config use the given file home as "home" directory.

Method Summary

Modifier and Type	Method	Description
static boolean	flag(java.lang.String value)	Converts a ssh config flag value (yes/true/on - no/false/off) into an boolean.
java.lang.String	getLocalUserName()	Retrieves the local user name as given in the constructor.
OpenSshConfigFile.HostEntry	lookup(java.lang.String hostName, int port, java.lang.String userName)	Locate the configuration for a specific host request.
private OpenSshConfigFile.HostEntry	lookup(java.lang.String hostName, int port, java.lang.String userName, boolean fillDefaults)
OpenSshConfigFile.HostEntry	lookupDefault(java.lang.String hostName, int port, java.lang.String userName)	Locate the configuration for a specific host request and if the configuration has no values for SshConstants.HOST_NAME, SshConstants.PORT, SshConstants.USER, or SshConstants.CONNECTION_ATTEMPTS, fill those values with defaults from the arguments: ssh config key value from argument HostName hostName Port port > 0 ? port : 22 User userName ConnectionAttempts 1
private java.util.List<OpenSshConfigFile.HostEntry>	parse(java.io.BufferedReader reader)
private static java.util.List<java.lang.String>	parseList(java.lang.String argument)	Splits the argument into a list of whitespace-separated elements.
private static int	parseToken(java.lang.String argument, int from, int to, java.util.List<java.lang.String> result)	Parses a token up to the next whitespace not inside a string quoted by single or double quotes.
private static boolean	patternMatchesHost(java.lang.String pattern, java.lang.String name)
static int	positive(java.lang.String value)	Converts a positive value into an int.
private OpenSshConfigFile.State	refresh()
private static java.lang.String	stripWhitespace(java.lang.String value)
static int	timeSpec(java.lang.String value)	Converts an OpenSSH time value into a number of seconds.
private java.lang.String	toCacheKey(java.lang.String hostName, int port, java.lang.String userName)
private static java.io.File	toFile(java.lang.String path, java.io.File home)
java.lang.String	toString()
protected java.lang.String	validate(java.lang.String key, java.lang.String value)	Hook to perform validation on a single value, or to sanitize it.
protected java.util.List<java.lang.String>	validate(java.lang.String key, java.util.List<java.lang.String> value)	Hook to perform validation on values, or to sanitize them.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

home

private final java.io.File home

The user's home directory, as key files may be relative to here.

configFile

private final java.io.File configFile

The .ssh/config file we read and monitor for updates.

localUserName

private final java.lang.String localUserName

User name of the user on the host OS.

lastModified

private java.time.Instant lastModified

Modification time of configFile when it was last loaded.

state

private OpenSshConfigFile.State state

State read from the config file, plus the cache.

Constructor Detail

OpenSshConfigFile

public OpenSshConfigFile(@NonNull
                         java.io.File home,
                         @NonNull
                         java.io.File config,
                         @NonNull
                         java.lang.String localUserName)

Creates a new OpenSshConfigFile that will read the config from file config use the given file home as "home" directory.

Parameters:

home - user's home directory for the purpose of ~ replacement

config - file to load.

localUserName - user name of the current user on the local host OS

Method Detail

lookup

@NonNull
public OpenSshConfigFile.HostEntry lookup(@NonNull
                                          java.lang.String hostName,
                                          int port,
                                          java.lang.String userName)

Locate the configuration for a specific host request.

Specified by:

lookup in interface SshConfigStore

Parameters:

hostName - the name the user has supplied to the SSH tool. This may be a real host name, or it may just be a "Host" block in the configuration file.

port - the user supplied; <= 0 if none

userName - the user supplied, may be null or empty if none given

Returns:

the configuration for the requested name.

lookupDefault

@NonNull
public OpenSshConfigFile.HostEntry lookupDefault(@NonNull
                                                 java.lang.String hostName,
                                                 int port,
                                                 java.lang.String userName)

Description copied from interface: SshConfigStore

Locate the configuration for a specific host request and if the configuration has no values for SshConstants.HOST_NAME, SshConstants.PORT, SshConstants.USER, or SshConstants.CONNECTION_ATTEMPTS, fill those values with defaults from the arguments:

ssh config key	value from argument
HostName	hostName
Port	port > 0 ? port : 22
User	userName
ConnectionAttempts	1

Specified by:

lookupDefault in interface SshConfigStore

Parameters:

hostName - host name to look up

port - port number; <= 0 if none

userName - the user name, may be null or empty if none given

Returns:

the configuration for the requested name.

lookup

private OpenSshConfigFile.HostEntry lookup(@NonNull
                                           java.lang.String hostName,
                                           int port,
                                           java.lang.String userName,
                                           boolean fillDefaults)

toCacheKey

@NonNull
private java.lang.String toCacheKey(@NonNull
                                    java.lang.String hostName,
                                    int port,
                                    java.lang.String userName)

refresh

private OpenSshConfigFile.State refresh()

parse

private java.util.List<OpenSshConfigFile.HostEntry> parse(java.io.BufferedReader reader)
                                                   throws java.io.IOException

Throws:

java.io.IOException

parseList

private static java.util.List<java.lang.String> parseList(java.lang.String argument)

Splits the argument into a list of whitespace-separated elements. Elements containing whitespace must be quoted and will be de-quoted. Backslash-escapes are handled for quotes and blanks.

Parameters:

argument - argument part of the configuration line as read from the config file

Returns:

a List of elements, possibly empty and possibly containing empty elements, but not containing null

parseToken

private static int parseToken(java.lang.String argument,
                              int from,
                              int to,
                              java.util.List<java.lang.String> result)

Parses a token up to the next whitespace not inside a string quoted by single or double quotes. Inside a string, quotes can be escaped by backslash characters. Outside of a string, "\ " can be used to include a space in a token; inside a string "\ " is taken literally as '\' followed by ' '.

Parameters:

argument - to parse the token out of

from - index at the beginning of the token

to - index one after the last character to look at

result - a list collecting tokens to which the parsed token is added

Returns:

the index after the token

validate

protected java.lang.String validate(java.lang.String key,
                                    java.lang.String value)

Hook to perform validation on a single value, or to sanitize it. If this throws an (unchecked) exception, parsing of the file is abandoned.

Parameters:

key - of the entry

value - as read from the config file

Returns:

the validated and possibly sanitized value

validate

protected java.util.List<java.lang.String> validate(java.lang.String key,
                                                    java.util.List<java.lang.String> value)

Hook to perform validation on values, or to sanitize them. If this throws an (unchecked) exception, parsing of the file is abandoned.

Parameters:

key - of the entry

value - list of arguments as read from the config file

Returns:

a List of values, possibly empty and possibly containing empty elements, but not containing null

patternMatchesHost

private static boolean patternMatchesHost(java.lang.String pattern,
                                          java.lang.String name)

stripWhitespace

private static java.lang.String stripWhitespace(java.lang.String value)

toFile

private static java.io.File toFile(java.lang.String path,
                                   java.io.File home)

positive

public static int positive(java.lang.String value)

Converts a positive value into an int.

Parameters:

value - to convert

Returns:

the value, or -1 if it wasn't a positive integral value

flag

public static boolean flag(java.lang.String value)

Converts a ssh config flag value (yes/true/on - no/false/off) into an boolean.

Parameters:

value - to convert

Returns:

true if value is "yes", "on", or "true"; false otherwise

timeSpec

public static int timeSpec(java.lang.String value)

Converts an OpenSSH time value into a number of seconds. The format is defined by OpenSSH as a sequence of (positive) integers with suffixes for seconds, minutes, hours, days, and weeks.

Parameters:

value - to convert

Returns:

the parsed value as a number of seconds, or -1 if the value is not a valid OpenSSH time value

See Also:

OpenBSD man 5 sshd_config, section TIME FORMATS

getLocalUserName

public java.lang.String getLocalUserName()

Retrieves the local user name as given in the constructor.

Returns:

the user name

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object