fix(sshd_config): Overall improvements

handlers/ssh_config/Config.g4

@@ -0,0 +1,41 @@
+grammar Config;
+
+lineStatement
+    : (entry | leadingComment | WHITESPACE?) EOF
+    ;
+
+entry
+    : WHITESPACE? key? separator? value? leadingComment?
+    ;
+
+separator
+    : WHITESPACE
+    ;
+
+key
+    : STRING
+    ;
+
+value
+    : (STRING WHITESPACE)* STRING? WHITESPACE?
+    ;
+
+leadingComment
+    : HASH WHITESPACE? (STRING WHITESPACE?)+
+    ;
+
+HASH
+    : '#'
+    ;
+
+WHITESPACE
+    : [ \t]+
+    ;
+
+STRING
+    : ~(' ' | '\t' | '\r' | '\n' | '#')+
+    ;
+
+NEWLINE
+    : '\r'? '\n'
+    ;

handlers/ssh_config/ast/parser/Config.interp

@@ -0,0 +1,25 @@
+token literal names:
+null
+'#'
+null
+null
+null
+
+token symbolic names:
+null
+HASH
+WHITESPACE
+STRING
+NEWLINE
+
+rule names:
+lineStatement
+entry
+separator
+key
+value
+leadingComment
+
+
+atn:
+[4, 1, 4, 66, 2, 0, 7, 0, 2, 1, 7, 1, 2, 2, 7, 2, 2, 3, 7, 3, 2, 4, 7, 4, 2, 5, 7, 5, 1, 0, 1, 0, 1, 0, 3, 0, 16, 8, 0, 3, 0, 18, 8, 0, 1, 0, 1, 0, 1, 1, 3, 1, 23, 8, 1, 1, 1, 3, 1, 26, 8, 1, 1, 1, 3, 1, 29, 8, 1, 1, 1, 3, 1, 32, 8, 1, 1, 1, 3, 1, 35, 8, 1, 1, 2, 1, 2, 1, 3, 1, 3, 1, 4, 1, 4, 5, 4, 43, 8, 4, 10, 4, 12, 4, 46, 9, 4, 1, 4, 3, 4, 49, 8, 4, 1, 4, 3, 4, 52, 8, 4, 1, 5, 1, 5, 3, 5, 56, 8, 5, 1, 5, 1, 5, 3, 5, 60, 8, 5, 4, 5, 62, 8, 5, 11, 5, 12, 5, 63, 1, 5, 0, 0, 6, 0, 2, 4, 6, 8, 10, 0, 0, 73, 0, 17, 1, 0, 0, 0, 2, 22, 1, 0, 0, 0, 4, 36, 1, 0, 0, 0, 6, 38, 1, 0, 0, 0, 8, 44, 1, 0, 0, 0, 10, 53, 1, 0, 0, 0, 12, 18, 3, 2, 1, 0, 13, 18, 3, 10, 5, 0, 14, 16, 5, 2, 0, 0, 15, 14, 1, 0, 0, 0, 15, 16, 1, 0, 0, 0, 16, 18, 1, 0, 0, 0, 17, 12, 1, 0, 0, 0, 17, 13, 1, 0, 0, 0, 17, 15, 1, 0, 0, 0, 18, 19, 1, 0, 0, 0, 19, 20, 5, 0, 0, 1, 20, 1, 1, 0, 0, 0, 21, 23, 5, 2, 0, 0, 22, 21, 1, 0, 0, 0, 22, 23, 1, 0, 0, 0, 23, 25, 1, 0, 0, 0, 24, 26, 3, 6, 3, 0, 25, 24, 1, 0, 0, 0, 25, 26, 1, 0, 0, 0, 26, 28, 1, 0, 0, 0, 27, 29, 3, 4, 2, 0, 28, 27, 1, 0, 0, 0, 28, 29, 1, 0, 0, 0, 29, 31, 1, 0, 0, 0, 30, 32, 3, 8, 4, 0, 31, 30, 1, 0, 0, 0, 31, 32, 1, 0, 0, 0, 32, 34, 1, 0, 0, 0, 33, 35, 3, 10, 5, 0, 34, 33, 1, 0, 0, 0, 34, 35, 1, 0, 0, 0, 35, 3, 1, 0, 0, 0, 36, 37, 5, 2, 0, 0, 37, 5, 1, 0, 0, 0, 38, 39, 5, 3, 0, 0, 39, 7, 1, 0, 0, 0, 40, 41, 5, 3, 0, 0, 41, 43, 5, 2, 0, 0, 42, 40, 1, 0, 0, 0, 43, 46, 1, 0, 0, 0, 44, 42, 1, 0, 0, 0, 44, 45, 1, 0, 0, 0, 45, 48, 1, 0, 0, 0, 46, 44, 1, 0, 0, 0, 47, 49, 5, 3, 0, 0, 48, 47, 1, 0, 0, 0, 48, 49, 1, 0, 0, 0, 49, 51, 1, 0, 0, 0, 50, 52, 5, 2, 0, 0, 51, 50, 1, 0, 0, 0, 51, 52, 1, 0, 0, 0, 52, 9, 1, 0, 0, 0, 53, 55, 5, 1, 0, 0, 54, 56, 5, 2, 0, 0, 55, 54, 1, 0, 0, 0, 55, 56, 1, 0, 0, 0, 56, 61, 1, 0, 0, 0, 57, 59, 5, 3, 0, 0, 58, 60, 5, 2, 0, 0, 59, 58, 1, 0, 0, 0, 59, 60, 1, 0, 0, 0, 60, 62, 1, 0, 0, 0, 61, 57, 1, 0, 0, 0, 62, 63, 1, 0, 0, 0, 63, 61, 1, 0, 0, 0, 63, 64, 1, 0, 0, 0, 64, 11, 1, 0, 0, 0, 13, 15, 17, 22, 25, 28, 31, 34, 44, 48, 51, 55, 59, 63]

handlers/ssh_config/ast/parser/Config.tokens

@@ -0,0 +1,5 @@
+HASH=1
+WHITESPACE=2
+STRING=3
+NEWLINE=4
+'#'=1

handlers/ssh_config/ast/parser/ConfigLexer.interp

@@ -0,0 +1,29 @@
+token literal names:
+null
+'#'
+null
+null
+null
+
+token symbolic names:
+null
+HASH
+WHITESPACE
+STRING
+NEWLINE
+
+rule names:
+HASH
+WHITESPACE
+STRING
+NEWLINE
+
+channel names:
+DEFAULT_TOKEN_CHANNEL
+HIDDEN
+
+mode names:
+DEFAULT_MODE
+
+atn:
+[4, 0, 4, 26, 6, -1, 2, 0, 7, 0, 2, 1, 7, 1, 2, 2, 7, 2, 2, 3, 7, 3, 1, 0, 1, 0, 1, 1, 4, 1, 13, 8, 1, 11, 1, 12, 1, 14, 1, 2, 4, 2, 18, 8, 2, 11, 2, 12, 2, 19, 1, 3, 3, 3, 23, 8, 3, 1, 3, 1, 3, 0, 0, 4, 1, 1, 3, 2, 5, 3, 7, 4, 1, 0, 2, 2, 0, 9, 9, 32, 32, 4, 0, 9, 10, 13, 13, 32, 32, 35, 35, 28, 0, 1, 1, 0, 0, 0, 0, 3, 1, 0, 0, 0, 0, 5, 1, 0, 0, 0, 0, 7, 1, 0, 0, 0, 1, 9, 1, 0, 0, 0, 3, 12, 1, 0, 0, 0, 5, 17, 1, 0, 0, 0, 7, 22, 1, 0, 0, 0, 9, 10, 5, 35, 0, 0, 10, 2, 1, 0, 0, 0, 11, 13, 7, 0, 0, 0, 12, 11, 1, 0, 0, 0, 13, 14, 1, 0, 0, 0, 14, 12, 1, 0, 0, 0, 14, 15, 1, 0, 0, 0, 15, 4, 1, 0, 0, 0, 16, 18, 8, 1, 0, 0, 17, 16, 1, 0, 0, 0, 18, 19, 1, 0, 0, 0, 19, 17, 1, 0, 0, 0, 19, 20, 1, 0, 0, 0, 20, 6, 1, 0, 0, 0, 21, 23, 5, 13, 0, 0, 22, 21, 1, 0, 0, 0, 22, 23, 1, 0, 0, 0, 23, 24, 1, 0, 0, 0, 24, 25, 5, 10, 0, 0, 25, 8, 1, 0, 0, 0, 4, 0, 14, 19, 22, 0]

handlers/ssh_config/ast/parser/ConfigLexer.tokens

@@ -0,0 +1,5 @@
+HASH=1
+WHITESPACE=2
+STRING=3
+NEWLINE=4
+'#'=1

handlers/ssh_config/ast/parser/config_base_listener.go

@@ -0,0 +1,58 @@
+// Code generated from Config.g4 by ANTLR 4.13.0. DO NOT EDIT.
+
+package parser // Config
+
+import "github.com/antlr4-go/antlr/v4"
+
+// BaseConfigListener is a complete listener for a parse tree produced by ConfigParser.
+type BaseConfigListener struct{}
+
+var _ ConfigListener = &BaseConfigListener{}
+
+// VisitTerminal is called when a terminal node is visited.
+func (s *BaseConfigListener) VisitTerminal(node antlr.TerminalNode) {}
+
+// VisitErrorNode is called when an error node is visited.
+func (s *BaseConfigListener) VisitErrorNode(node antlr.ErrorNode) {}
+
+// EnterEveryRule is called when any rule is entered.
+func (s *BaseConfigListener) EnterEveryRule(ctx antlr.ParserRuleContext) {}
+
+// ExitEveryRule is called when any rule is exited.
+func (s *BaseConfigListener) ExitEveryRule(ctx antlr.ParserRuleContext) {}
+
+// EnterLineStatement is called when production lineStatement is entered.
+func (s *BaseConfigListener) EnterLineStatement(ctx *LineStatementContext) {}
+
+// ExitLineStatement is called when production lineStatement is exited.
+func (s *BaseConfigListener) ExitLineStatement(ctx *LineStatementContext) {}
+
+// EnterEntry is called when production entry is entered.
+func (s *BaseConfigListener) EnterEntry(ctx *EntryContext) {}
+
+// ExitEntry is called when production entry is exited.
+func (s *BaseConfigListener) ExitEntry(ctx *EntryContext) {}
+
+// EnterSeparator is called when production separator is entered.
+func (s *BaseConfigListener) EnterSeparator(ctx *SeparatorContext) {}
+
+// ExitSeparator is called when production separator is exited.
+func (s *BaseConfigListener) ExitSeparator(ctx *SeparatorContext) {}
+
+// EnterKey is called when production key is entered.
+func (s *BaseConfigListener) EnterKey(ctx *KeyContext) {}
+
+// ExitKey is called when production key is exited.
+func (s *BaseConfigListener) ExitKey(ctx *KeyContext) {}
+
+// EnterValue is called when production value is entered.
+func (s *BaseConfigListener) EnterValue(ctx *ValueContext) {}
+
+// ExitValue is called when production value is exited.
+func (s *BaseConfigListener) ExitValue(ctx *ValueContext) {}
+
+// EnterLeadingComment is called when production leadingComment is entered.
+func (s *BaseConfigListener) EnterLeadingComment(ctx *LeadingCommentContext) {}
+
+// ExitLeadingComment is called when production leadingComment is exited.
+func (s *BaseConfigListener) ExitLeadingComment(ctx *LeadingCommentContext) {}

handlers/ssh_config/ast/parser/config_lexer.go

@@ -0,0 +1,112 @@
+// Code generated from Config.g4 by ANTLR 4.13.0. DO NOT EDIT.
+
+package parser
+
+import (
+	"fmt"
+	"github.com/antlr4-go/antlr/v4"
+	"sync"
+	"unicode"
+)
+
+// Suppress unused import error
+var _ = fmt.Printf
+var _ = sync.Once{}
+var _ = unicode.IsLetter
+
+type ConfigLexer struct {
+	*antlr.BaseLexer
+	channelNames []string
+	modeNames    []string
+	// TODO: EOF string
+}
+
+var ConfigLexerLexerStaticData struct {
+	once                   sync.Once
+	serializedATN          []int32
+	ChannelNames           []string
+	ModeNames              []string
+	LiteralNames           []string
+	SymbolicNames          []string
+	RuleNames              []string
+	PredictionContextCache *antlr.PredictionContextCache
+	atn                    *antlr.ATN
+	decisionToDFA          []*antlr.DFA
+}
+
+func configlexerLexerInit() {
+	staticData := &ConfigLexerLexerStaticData
+	staticData.ChannelNames = []string{
+		"DEFAULT_TOKEN_CHANNEL", "HIDDEN",
+	}
+	staticData.ModeNames = []string{
+		"DEFAULT_MODE",
+	}
+	staticData.LiteralNames = []string{
+		"", "'#'",
+	}
+	staticData.SymbolicNames = []string{
+		"", "HASH", "WHITESPACE", "STRING", "NEWLINE",
+	}
+	staticData.RuleNames = []string{
+		"HASH", "WHITESPACE", "STRING", "NEWLINE",
+	}
+	staticData.PredictionContextCache = antlr.NewPredictionContextCache()
+	staticData.serializedATN = []int32{
+		4, 0, 4, 26, 6, -1, 2, 0, 7, 0, 2, 1, 7, 1, 2, 2, 7, 2, 2, 3, 7, 3, 1,
+		0, 1, 0, 1, 1, 4, 1, 13, 8, 1, 11, 1, 12, 1, 14, 1, 2, 4, 2, 18, 8, 2,
+		11, 2, 12, 2, 19, 1, 3, 3, 3, 23, 8, 3, 1, 3, 1, 3, 0, 0, 4, 1, 1, 3, 2,
+		5, 3, 7, 4, 1, 0, 2, 2, 0, 9, 9, 32, 32, 4, 0, 9, 10, 13, 13, 32, 32, 35,
+		35, 28, 0, 1, 1, 0, 0, 0, 0, 3, 1, 0, 0, 0, 0, 5, 1, 0, 0, 0, 0, 7, 1,
+		0, 0, 0, 1, 9, 1, 0, 0, 0, 3, 12, 1, 0, 0, 0, 5, 17, 1, 0, 0, 0, 7, 22,
+		1, 0, 0, 0, 9, 10, 5, 35, 0, 0, 10, 2, 1, 0, 0, 0, 11, 13, 7, 0, 0, 0,
+		12, 11, 1, 0, 0, 0, 13, 14, 1, 0, 0, 0, 14, 12, 1, 0, 0, 0, 14, 15, 1,
+		0, 0, 0, 15, 4, 1, 0, 0, 0, 16, 18, 8, 1, 0, 0, 17, 16, 1, 0, 0, 0, 18,
+		19, 1, 0, 0, 0, 19, 17, 1, 0, 0, 0, 19, 20, 1, 0, 0, 0, 20, 6, 1, 0, 0,
+		0, 21, 23, 5, 13, 0, 0, 22, 21, 1, 0, 0, 0, 22, 23, 1, 0, 0, 0, 23, 24,
+		1, 0, 0, 0, 24, 25, 5, 10, 0, 0, 25, 8, 1, 0, 0, 0, 4, 0, 14, 19, 22, 0,
+	}
+	deserializer := antlr.NewATNDeserializer(nil)
+	staticData.atn = deserializer.Deserialize(staticData.serializedATN)
+	atn := staticData.atn
+	staticData.decisionToDFA = make([]*antlr.DFA, len(atn.DecisionToState))
+	decisionToDFA := staticData.decisionToDFA
+	for index, state := range atn.DecisionToState {
+		decisionToDFA[index] = antlr.NewDFA(state, index)
+	}
+}
+
+// ConfigLexerInit initializes any static state used to implement ConfigLexer. By default the
+// static state used to implement the lexer is lazily initialized during the first call to
+// NewConfigLexer(). You can call this function if you wish to initialize the static state ahead
+// of time.
+func ConfigLexerInit() {
+	staticData := &ConfigLexerLexerStaticData
+	staticData.once.Do(configlexerLexerInit)
+}
+
+// NewConfigLexer produces a new lexer instance for the optional input antlr.CharStream.
+func NewConfigLexer(input antlr.CharStream) *ConfigLexer {
+	ConfigLexerInit()
+	l := new(ConfigLexer)
+	l.BaseLexer = antlr.NewBaseLexer(input)
+	staticData := &ConfigLexerLexerStaticData
+	l.Interpreter = antlr.NewLexerATNSimulator(l, staticData.atn, staticData.decisionToDFA, staticData.PredictionContextCache)
+	l.channelNames = staticData.ChannelNames
+	l.modeNames = staticData.ModeNames
+	l.RuleNames = staticData.RuleNames
+	l.LiteralNames = staticData.LiteralNames
+	l.SymbolicNames = staticData.SymbolicNames
+	l.GrammarFileName = "Config.g4"
+	// TODO: l.EOF = antlr.TokenEOF
+
+	return l
+}
+
+// ConfigLexer tokens.
+const (
+	ConfigLexerHASH       = 1
+	ConfigLexerWHITESPACE = 2
+	ConfigLexerSTRING     = 3
+	ConfigLexerNEWLINE    = 4
+)

handlers/ssh_config/ast/parser/config_listener.go

@@ -0,0 +1,46 @@
+// Code generated from Config.g4 by ANTLR 4.13.0. DO NOT EDIT.
+
+package parser // Config
+
+import "github.com/antlr4-go/antlr/v4"
+
+// ConfigListener is a complete listener for a parse tree produced by ConfigParser.
+type ConfigListener interface {
+	antlr.ParseTreeListener
+
+	// EnterLineStatement is called when entering the lineStatement production.
+	EnterLineStatement(c *LineStatementContext)
+
+	// EnterEntry is called when entering the entry production.
+	EnterEntry(c *EntryContext)
+
+	// EnterSeparator is called when entering the separator production.
+	EnterSeparator(c *SeparatorContext)
+
+	// EnterKey is called when entering the key production.
+	EnterKey(c *KeyContext)
+
+	// EnterValue is called when entering the value production.
+	EnterValue(c *ValueContext)
+
+	// EnterLeadingComment is called when entering the leadingComment production.
+	EnterLeadingComment(c *LeadingCommentContext)
+
+	// ExitLineStatement is called when exiting the lineStatement production.
+	ExitLineStatement(c *LineStatementContext)
+
+	// ExitEntry is called when exiting the entry production.
+	ExitEntry(c *EntryContext)
+
+	// ExitSeparator is called when exiting the separator production.
+	ExitSeparator(c *SeparatorContext)
+
+	// ExitKey is called when exiting the key production.
+	ExitKey(c *KeyContext)
+
+	// ExitValue is called when exiting the value production.
+	ExitValue(c *ValueContext)
+
+	// ExitLeadingComment is called when exiting the leadingComment production.
+	ExitLeadingComment(c *LeadingCommentContext)
+}

handlers/ssh_config/ast/ssh_config.go

@@ -0,0 +1,62 @@
+package ast
+
+import (
+	"config-lsp/common"
+	commonparser "config-lsp/common/parser"
+	matchparser "config-lsp/handlers/sshd_config/fields/match-parser"
+	"github.com/emirpasic/gods/maps/treemap"
+)
+
+type SSHKey struct {
+	common.LocationRange
+	Value commonparser.ParsedString
+	Key   string
+}
+
+type SSHSeparator struct {
+	common.LocationRange
+	Value commonparser.ParsedString
+}
+
+type SSHValue struct {
+	common.LocationRange
+	Value commonparser.ParsedString
+}
+
+type SSHOption struct {
+	common.LocationRange
+	Value commonparser.ParsedString
+
+	Key         *SSHKey
+	Separator   *SSHSeparator
+	OptionValue *SSHValue
+}
+
+type SSHMatchBlock struct {
+	common.LocationRange
+	MatchOption *SSHOption
+	MatchValue  *matchparser.Match
+
+	// [uint32]*SSHOption -> line number -> *SSHOption
+	Options *treemap.Map
+}
+
+type SSHHostBlock struct {
+	common.LocationRange
+	HostOption *SSHOption
+	HostValue  string
+
+	// [uint32]*SSHOption -> line number -> *SSHOption
+	Others *treemap.Map
+}
+
+type SSHConfig struct {
+	// [uint32]SSHOption -> line number -> *SSHEntry
+	RootOptions *treemap.Map
+
+	MatchBlosks []*SSHMatchBlock
+	HostBlocks  []*SSHHostBlock
+
+	// [uint32]{} -> line number -> {}
+	CommentLines map[uint32]struct{}
+}

handlers/ssh_config/ast/ssh_config_fields.go

@@ -0,0 +1 @@
+package ast

handlers/sshd_config/Config.g4

@@ -13,17 +13,23 @@ separator
     ;
 
 key
-    : STRING
+    : string
     ;
 
 value
-    : (STRING WHITESPACE)* STRING? WHITESPACE?
+    : (string WHITESPACE)* string? WHITESPACE?
     ;
 
 leadingComment
-    : HASH WHITESPACE? (STRING WHITESPACE?)+
+    : HASH WHITESPACE? (string WHITESPACE?)+
     ;
 
+string
+    : (QUOTED_STRING | STRING)
+    ;
+
+///////////////////////////////////////////////
+
 HASH
     : '#'
     ;
@@ -33,9 +39,13 @@ WHITESPACE
     ;
 
 STRING
-    : ~(' ' | '\t' | '\r' | '\n' | '#')+
+    : ~('#' | '\r' | '\n' | '"' | ' ' | '\t')+
     ;
 
 NEWLINE
     : '\r'? '\n'
     ;
+
+QUOTED_STRING
+    : '"' WHITESPACE? (STRING WHITESPACE)* STRING? ('"')?
+    ;

handlers/sshd_config/analyzer/analyzer.go

@@ -12,7 +12,7 @@ import (
 func Analyze(
 	d *sshdconfig.SSHDocument,
 ) []protocol.Diagnostic {
-	errors := analyzeOptionsAreValid(d)
+	errors := analyzeStructureIsValid(d)
 
 	if len(errors) > 0 {
 		return errsToDiagnostics(errors)

handlers/sshd_config/analyzer/options.go

@@ -11,7 +11,7 @@ import (
 	"fmt"
 )
 
-func analyzeOptionsAreValid(
+func analyzeStructureIsValid(
 	d *sshdconfig.SSHDocument,
 ) []common.LSPError {
 	errs := make([]common.LSPError, 0)
@@ -39,48 +39,66 @@ func checkOption(
 ) []common.LSPError {
 	errs := make([]common.LSPError, 0)
 
-	if option.Key != nil {
+	if option.Key == nil {
-		docOption, found := fields.Options[option.Key.Key]
+		return errs
+	}
 
-		if !found {
+	errs = append(errs, checkIsUsingDoubleQuotes(option.Key.Value, option.Key.LocationRange)...)
-			errs = append(errs, common.LSPError{
+	errs = append(errs, checkQuotesAreClosed(option.Key.Value, option.Key.LocationRange)...)
-				Range: option.Key.LocationRange,
-				Err:   errors.New(fmt.Sprintf("Unknown option: %s", option.Key.Key)),
-			})
 
-			return errs
+	docOption, found := fields.Options[option.Key.Key]
-		}
 
-		if _, found := fields.MatchAllowedOptions[option.Key.Key]; !found && isInMatchBlock {
+	if !found {
-			errs = append(errs, common.LSPError{
+		errs = append(errs, common.LSPError{
-				Range: option.Key.LocationRange,
+			Range: option.Key.LocationRange,
-				Err:   errors.New(fmt.Sprintf("Option '%s' is not allowed inside Match blocks", option.Key.Key)),
+			Err:   errors.New(fmt.Sprintf("Unknown option: %s", option.Key.Key)),
-			})
+		})
 
-			return errs
+		return errs
-		}
+	}
 
-		if option.OptionValue == nil || option.OptionValue.Value.Value == "" {
+	if _, found := fields.MatchAllowedOptions[option.Key.Key]; !found && isInMatchBlock {
-			errs = append(errs, common.LSPError{
+		errs = append(errs, common.LSPError{
-				Range: option.Key.LocationRange,
+			Range: option.Key.LocationRange,
-				Err:   errors.New(fmt.Sprintf("Option '%s' requires a value", option.Key.Key)),
+			Err:   errors.New(fmt.Sprintf("Option '%s' is not allowed inside Match blocks", option.Key.Key)),
-			})
+		})
-		} else {
-			invalidValues := docOption.CheckIsValid(option.OptionValue.Value.Value)
 
-			errs = append(
+		return errs
-				errs,
+	}
-				utils.Map(
-					invalidValues,
-					func(invalidValue *docvalues.InvalidValue) common.LSPError {
-						err := docvalues.LSPErrorFromInvalidValue(option.Start.Line, *invalidValue)
-						err.ShiftCharacter(option.OptionValue.Start.Character)
 
-						return err
+	if option.OptionValue == nil || option.OptionValue.Value.Value == "" {
-					},
+		errs = append(errs, common.LSPError{
-				)...,
+			Range: option.Key.LocationRange,
-			)
+			Err:   errors.New(fmt.Sprintf("Option '%s' requires a value", option.Key.Key)),
-		}
+		})
+	} else {
+		errs = append(errs, checkIsUsingDoubleQuotes(option.OptionValue.Value, option.OptionValue.LocationRange)...)
+		errs = append(errs, checkQuotesAreClosed(option.OptionValue.Value, option.OptionValue.LocationRange)...)
+
+		invalidValues := docOption.CheckIsValid(option.OptionValue.Value.Value)
+
+		errs = append(
+			errs,
+			utils.Map(
+				invalidValues,
+				func(invalidValue *docvalues.InvalidValue) common.LSPError {
+					err := docvalues.LSPErrorFromInvalidValue(option.Start.Line, *invalidValue)
+					err.ShiftCharacter(option.OptionValue.Start.Character)
+
+					return err
+				},
+			)...,
+		)
+	}
+
+	if option.Separator == nil || option.Separator.Value.Value == "" {
+		errs = append(errs, common.LSPError{
+			Range: option.Key.LocationRange,
+			Err:   errors.New(fmt.Sprintf("There should be a separator between an option and its value")),
+		})
+	} else {
+		errs = append(errs, checkIsUsingDoubleQuotes(option.Separator.Value, option.Separator.LocationRange)...)
+		errs = append(errs, checkQuotesAreClosed(option.Separator.Value, option.Separator.LocationRange)...)
 	}
 
 	return errs

handlers/sshd_config/analyzer/quotes.go

@@ -0,0 +1,59 @@
+package analyzer
+
+import (
+	"config-lsp/common"
+	commonparser "config-lsp/common/parser"
+	sshdconfig "config-lsp/handlers/sshd_config"
+	"errors"
+	"strings"
+)
+
+func analyzeQuotesAreValid(
+	d *sshdconfig.SSHDocument,
+) []common.LSPError {
+	errs := make([]common.LSPError, 0)
+
+	for _, option := range d.Config.GetAllOptions() {
+		errs = append(errs, checkIsUsingDoubleQuotes(option.Key.Value, option.Key.LocationRange)...)
+		errs = append(errs, checkIsUsingDoubleQuotes(option.OptionValue.Value, option.OptionValue.LocationRange)...)
+
+		errs = append(errs, checkQuotesAreClosed(option.Key.Value, option.Key.LocationRange)...)
+		errs = append(errs, checkQuotesAreClosed(option.OptionValue.Value, option.OptionValue.LocationRange)...)
+	}
+
+	return errs
+}
+
+func checkIsUsingDoubleQuotes(
+	value commonparser.ParsedString,
+	valueRange common.LocationRange,
+) []common.LSPError {
+	singleQuotePosition := strings.Index(value.Raw, "'")
+
+	if singleQuotePosition != -1 {
+		return []common.LSPError{
+			{
+				Range: valueRange,
+				Err:   errors.New("sshd_config does not support single quotes. Use double quotes (\") instead."),
+			},
+		}
+	}
+
+	return nil
+}
+
+func checkQuotesAreClosed(
+	value commonparser.ParsedString,
+	valueRange common.LocationRange,
+) []common.LSPError {
+	if strings.Count(value.Raw, "\"")%2 != 0 {
+		return []common.LSPError{
+			{
+				Range: valueRange,
+				Err:   errors.New("There are unclosed quotes here. Make sure all quotes are closed."),
+			},
+		}
+	}
+
+	return nil
+}

handlers/sshd_config/analyzer/quotes_test.go

@@ -0,0 +1,62 @@
+package analyzer
+
+import (
+	testutils_test "config-lsp/handlers/sshd_config/test_utils"
+	"testing"
+)
+
+func TestSimpleInvalidQuotesExample(
+	t *testing.T,
+) {
+	d := testutils_test.DocumentFromInput(t, `
+PermitRootLogin 'yes'
+`)
+
+	errors := analyzeQuotesAreValid(d)
+
+	if !(len(errors) == 1) {
+		t.Errorf("Expected 1 error, got %v", len(errors))
+	}
+}
+
+func TestSingleQuotesKeyAndOptionExample(
+	t *testing.T,
+) {
+	d := testutils_test.DocumentFromInput(t, `
+'Port' '22'
+`)
+
+	errors := analyzeQuotesAreValid(d)
+
+	if !(len(errors) == 2) {
+		t.Errorf("Expected 2 errors, got %v", len(errors))
+	}
+}
+
+func TestSimpleUnclosedQuoteExample(
+	t *testing.T,
+) {
+	d := testutils_test.DocumentFromInput(t, `
+PermitRootLogin "yes
+`)
+
+	errors := analyzeQuotesAreValid(d)
+
+	if !(len(errors) == 1) {
+		t.Errorf("Expected 1 error, got %v", len(errors))
+	}
+}
+
+func TestIncompleteQuotesExample(
+	t *testing.T,
+) {
+	d := testutils_test.DocumentFromInput(t, `
+"Port 
+`)
+
+	errors := analyzeQuotesAreValid(d)
+
+	if !(len(errors) == 1) {
+		t.Errorf("Expected 1 error, got %v", len(errors))
+	}
+}

handlers/sshd_config/ast/listener.go

@@ -84,8 +84,12 @@ func (s *sshParserListener) EnterSeparator(ctx *parser.SeparatorContext) {
 	location := common.CharacterRangeFromCtx(ctx.BaseParserRuleContext)
 	location.ChangeBothLines(s.sshContext.line)
 
+	text := ctx.GetText()
+	value := commonparser.ParseRawString(text, commonparser.FullFeatures)
+
 	s.sshContext.currentOption.Separator = &SSHDSeparator{
 		LocationRange: location,
+		Value:         value,
 	}
 }
 

handlers/sshd_config/ast/parser/Config.interp

@@ -4,6 +4,7 @@ null
 null
 null
 null
+null
 
 token symbolic names:
 null
@@ -11,6 +12,7 @@ HASH
 WHITESPACE
 STRING
 NEWLINE
+QUOTED_STRING
 
 rule names:
 lineStatement
@@ -19,7 +21,8 @@ separator
 key
 value
 leadingComment
+string
 
 
 atn:
-[4, 1, 4, 66, 2, 0, 7, 0, 2, 1, 7, 1, 2, 2, 7, 2, 2, 3, 7, 3, 2, 4, 7, 4, 2, 5, 7, 5, 1, 0, 1, 0, 1, 0, 3, 0, 16, 8, 0, 3, 0, 18, 8, 0, 1, 0, 1, 0, 1, 1, 3, 1, 23, 8, 1, 1, 1, 3, 1, 26, 8, 1, 1, 1, 3, 1, 29, 8, 1, 1, 1, 3, 1, 32, 8, 1, 1, 1, 3, 1, 35, 8, 1, 1, 2, 1, 2, 1, 3, 1, 3, 1, 4, 1, 4, 5, 4, 43, 8, 4, 10, 4, 12, 4, 46, 9, 4, 1, 4, 3, 4, 49, 8, 4, 1, 4, 3, 4, 52, 8, 4, 1, 5, 1, 5, 3, 5, 56, 8, 5, 1, 5, 1, 5, 3, 5, 60, 8, 5, 4, 5, 62, 8, 5, 11, 5, 12, 5, 63, 1, 5, 0, 0, 6, 0, 2, 4, 6, 8, 10, 0, 0, 73, 0, 17, 1, 0, 0, 0, 2, 22, 1, 0, 0, 0, 4, 36, 1, 0, 0, 0, 6, 38, 1, 0, 0, 0, 8, 44, 1, 0, 0, 0, 10, 53, 1, 0, 0, 0, 12, 18, 3, 2, 1, 0, 13, 18, 3, 10, 5, 0, 14, 16, 5, 2, 0, 0, 15, 14, 1, 0, 0, 0, 15, 16, 1, 0, 0, 0, 16, 18, 1, 0, 0, 0, 17, 12, 1, 0, 0, 0, 17, 13, 1, 0, 0, 0, 17, 15, 1, 0, 0, 0, 18, 19, 1, 0, 0, 0, 19, 20, 5, 0, 0, 1, 20, 1, 1, 0, 0, 0, 21, 23, 5, 2, 0, 0, 22, 21, 1, 0, 0, 0, 22, 23, 1, 0, 0, 0, 23, 25, 1, 0, 0, 0, 24, 26, 3, 6, 3, 0, 25, 24, 1, 0, 0, 0, 25, 26, 1, 0, 0, 0, 26, 28, 1, 0, 0, 0, 27, 29, 3, 4, 2, 0, 28, 27, 1, 0, 0, 0, 28, 29, 1, 0, 0, 0, 29, 31, 1, 0, 0, 0, 30, 32, 3, 8, 4, 0, 31, 30, 1, 0, 0, 0, 31, 32, 1, 0, 0, 0, 32, 34, 1, 0, 0, 0, 33, 35, 3, 10, 5, 0, 34, 33, 1, 0, 0, 0, 34, 35, 1, 0, 0, 0, 35, 3, 1, 0, 0, 0, 36, 37, 5, 2, 0, 0, 37, 5, 1, 0, 0, 0, 38, 39, 5, 3, 0, 0, 39, 7, 1, 0, 0, 0, 40, 41, 5, 3, 0, 0, 41, 43, 5, 2, 0, 0, 42, 40, 1, 0, 0, 0, 43, 46, 1, 0, 0, 0, 44, 42, 1, 0, 0, 0, 44, 45, 1, 0, 0, 0, 45, 48, 1, 0, 0, 0, 46, 44, 1, 0, 0, 0, 47, 49, 5, 3, 0, 0, 48, 47, 1, 0, 0, 0, 48, 49, 1, 0, 0, 0, 49, 51, 1, 0, 0, 0, 50, 52, 5, 2, 0, 0, 51, 50, 1, 0, 0, 0, 51, 52, 1, 0, 0, 0, 52, 9, 1, 0, 0, 0, 53, 55, 5, 1, 0, 0, 54, 56, 5, 2, 0, 0, 55, 54, 1, 0, 0, 0, 55, 56, 1, 0, 0, 0, 56, 61, 1, 0, 0, 0, 57, 59, 5, 3, 0, 0, 58, 60, 5, 2, 0, 0, 59, 58, 1, 0, 0, 0, 59, 60, 1, 0, 0, 0, 60, 62, 1, 0, 0, 0, 61, 57, 1, 0, 0, 0, 62, 63, 1, 0, 0, 0, 63, 61, 1, 0, 0, 0, 63, 64, 1, 0, 0, 0, 64, 11, 1, 0, 0, 0, 13, 15, 17, 22, 25, 28, 31, 34, 44, 48, 51, 55, 59, 63]
+[4, 1, 5, 71, 2, 0, 7, 0, 2, 1, 7, 1, 2, 2, 7, 2, 2, 3, 7, 3, 2, 4, 7, 4, 2, 5, 7, 5, 2, 6, 7, 6, 1, 0, 1, 0, 1, 0, 3, 0, 18, 8, 0, 3, 0, 20, 8, 0, 1, 0, 1, 0, 1, 1, 3, 1, 25, 8, 1, 1, 1, 3, 1, 28, 8, 1, 1, 1, 3, 1, 31, 8, 1, 1, 1, 3, 1, 34, 8, 1, 1, 1, 3, 1, 37, 8, 1, 1, 2, 1, 2, 1, 3, 1, 3, 1, 4, 1, 4, 1, 4, 5, 4, 46, 8, 4, 10, 4, 12, 4, 49, 9, 4, 1, 4, 3, 4, 52, 8, 4, 1, 4, 3, 4, 55, 8, 4, 1, 5, 1, 5, 3, 5, 59, 8, 5, 1, 5, 1, 5, 3, 5, 63, 8, 5, 4, 5, 65, 8, 5, 11, 5, 12, 5, 66, 1, 6, 1, 6, 1, 6, 0, 0, 7, 0, 2, 4, 6, 8, 10, 12, 0, 1, 2, 0, 3, 3, 5, 5, 77, 0, 19, 1, 0, 0, 0, 2, 24, 1, 0, 0, 0, 4, 38, 1, 0, 0, 0, 6, 40, 1, 0, 0, 0, 8, 47, 1, 0, 0, 0, 10, 56, 1, 0, 0, 0, 12, 68, 1, 0, 0, 0, 14, 20, 3, 2, 1, 0, 15, 20, 3, 10, 5, 0, 16, 18, 5, 2, 0, 0, 17, 16, 1, 0, 0, 0, 17, 18, 1, 0, 0, 0, 18, 20, 1, 0, 0, 0, 19, 14, 1, 0, 0, 0, 19, 15, 1, 0, 0, 0, 19, 17, 1, 0, 0, 0, 20, 21, 1, 0, 0, 0, 21, 22, 5, 0, 0, 1, 22, 1, 1, 0, 0, 0, 23, 25, 5, 2, 0, 0, 24, 23, 1, 0, 0, 0, 24, 25, 1, 0, 0, 0, 25, 27, 1, 0, 0, 0, 26, 28, 3, 6, 3, 0, 27, 26, 1, 0, 0, 0, 27, 28, 1, 0, 0, 0, 28, 30, 1, 0, 0, 0, 29, 31, 3, 4, 2, 0, 30, 29, 1, 0, 0, 0, 30, 31, 1, 0, 0, 0, 31, 33, 1, 0, 0, 0, 32, 34, 3, 8, 4, 0, 33, 32, 1, 0, 0, 0, 33, 34, 1, 0, 0, 0, 34, 36, 1, 0, 0, 0, 35, 37, 3, 10, 5, 0, 36, 35, 1, 0, 0, 0, 36, 37, 1, 0, 0, 0, 37, 3, 1, 0, 0, 0, 38, 39, 5, 2, 0, 0, 39, 5, 1, 0, 0, 0, 40, 41, 3, 12, 6, 0, 41, 7, 1, 0, 0, 0, 42, 43, 3, 12, 6, 0, 43, 44, 5, 2, 0, 0, 44, 46, 1, 0, 0, 0, 45, 42, 1, 0, 0, 0, 46, 49, 1, 0, 0, 0, 47, 45, 1, 0, 0, 0, 47, 48, 1, 0, 0, 0, 48, 51, 1, 0, 0, 0, 49, 47, 1, 0, 0, 0, 50, 52, 3, 12, 6, 0, 51, 50, 1, 0, 0, 0, 51, 52, 1, 0, 0, 0, 52, 54, 1, 0, 0, 0, 53, 55, 5, 2, 0, 0, 54, 53, 1, 0, 0, 0, 54, 55, 1, 0, 0, 0, 55, 9, 1, 0, 0, 0, 56, 58, 5, 1, 0, 0, 57, 59, 5, 2, 0, 0, 58, 57, 1, 0, 0, 0, 58, 59, 1, 0, 0, 0, 59, 64, 1, 0, 0, 0, 60, 62, 3, 12, 6, 0, 61, 63, 5, 2, 0, 0, 62, 61, 1, 0, 0, 0, 62, 63, 1, 0, 0, 0, 63, 65, 1, 0, 0, 0, 64, 60, 1, 0, 0, 0, 65, 66, 1, 0, 0, 0, 66, 64, 1, 0, 0, 0, 66, 67, 1, 0, 0, 0, 67, 11, 1, 0, 0, 0, 68, 69, 7, 0, 0, 0, 69, 13, 1, 0, 0, 0, 13, 17, 19, 24, 27, 30, 33, 36, 47, 51, 54, 58, 62, 66]

handlers/sshd_config/ast/parser/Config.tokens

@@ -2,4 +2,5 @@ HASH=1
 WHITESPACE=2
 STRING=3
 NEWLINE=4
+QUOTED_STRING=5
 '#'=1

handlers/sshd_config/ast/parser/ConfigLexer.interp

@@ -4,6 +4,7 @@ null
 null
 null
 null
+null
 
 token symbolic names:
 null
@@ -11,12 +12,14 @@ HASH
 WHITESPACE
 STRING
 NEWLINE
+QUOTED_STRING
 
 rule names:
 HASH
 WHITESPACE
 STRING
 NEWLINE
+QUOTED_STRING
 
 channel names:
 DEFAULT_TOKEN_CHANNEL
@@ -26,4 +29,4 @@ mode names:
 DEFAULT_MODE
 
 atn:
-[4, 0, 4, 26, 6, -1, 2, 0, 7, 0, 2, 1, 7, 1, 2, 2, 7, 2, 2, 3, 7, 3, 1, 0, 1, 0, 1, 1, 4, 1, 13, 8, 1, 11, 1, 12, 1, 14, 1, 2, 4, 2, 18, 8, 2, 11, 2, 12, 2, 19, 1, 3, 3, 3, 23, 8, 3, 1, 3, 1, 3, 0, 0, 4, 1, 1, 3, 2, 5, 3, 7, 4, 1, 0, 2, 2, 0, 9, 9, 32, 32, 4, 0, 9, 10, 13, 13, 32, 32, 35, 35, 28, 0, 1, 1, 0, 0, 0, 0, 3, 1, 0, 0, 0, 0, 5, 1, 0, 0, 0, 0, 7, 1, 0, 0, 0, 1, 9, 1, 0, 0, 0, 3, 12, 1, 0, 0, 0, 5, 17, 1, 0, 0, 0, 7, 22, 1, 0, 0, 0, 9, 10, 5, 35, 0, 0, 10, 2, 1, 0, 0, 0, 11, 13, 7, 0, 0, 0, 12, 11, 1, 0, 0, 0, 13, 14, 1, 0, 0, 0, 14, 12, 1, 0, 0, 0, 14, 15, 1, 0, 0, 0, 15, 4, 1, 0, 0, 0, 16, 18, 8, 1, 0, 0, 17, 16, 1, 0, 0, 0, 18, 19, 1, 0, 0, 0, 19, 17, 1, 0, 0, 0, 19, 20, 1, 0, 0, 0, 20, 6, 1, 0, 0, 0, 21, 23, 5, 13, 0, 0, 22, 21, 1, 0, 0, 0, 22, 23, 1, 0, 0, 0, 23, 24, 1, 0, 0, 0, 24, 25, 5, 10, 0, 0, 25, 8, 1, 0, 0, 0, 4, 0, 14, 19, 22, 0]
+[4, 0, 5, 46, 6, -1, 2, 0, 7, 0, 2, 1, 7, 1, 2, 2, 7, 2, 2, 3, 7, 3, 2, 4, 7, 4, 1, 0, 1, 0, 1, 1, 4, 1, 15, 8, 1, 11, 1, 12, 1, 16, 1, 2, 4, 2, 20, 8, 2, 11, 2, 12, 2, 21, 1, 3, 3, 3, 25, 8, 3, 1, 3, 1, 3, 1, 4, 1, 4, 3, 4, 31, 8, 4, 1, 4, 1, 4, 1, 4, 5, 4, 36, 8, 4, 10, 4, 12, 4, 39, 9, 4, 1, 4, 3, 4, 42, 8, 4, 1, 4, 3, 4, 45, 8, 4, 0, 0, 5, 1, 1, 3, 2, 5, 3, 7, 4, 9, 5, 1, 0, 2, 2, 0, 9, 9, 32, 32, 4, 0, 9, 10, 13, 13, 32, 32, 34, 35, 52, 0, 1, 1, 0, 0, 0, 0, 3, 1, 0, 0, 0, 0, 5, 1, 0, 0, 0, 0, 7, 1, 0, 0, 0, 0, 9, 1, 0, 0, 0, 1, 11, 1, 0, 0, 0, 3, 14, 1, 0, 0, 0, 5, 19, 1, 0, 0, 0, 7, 24, 1, 0, 0, 0, 9, 28, 1, 0, 0, 0, 11, 12, 5, 35, 0, 0, 12, 2, 1, 0, 0, 0, 13, 15, 7, 0, 0, 0, 14, 13, 1, 0, 0, 0, 15, 16, 1, 0, 0, 0, 16, 14, 1, 0, 0, 0, 16, 17, 1, 0, 0, 0, 17, 4, 1, 0, 0, 0, 18, 20, 8, 1, 0, 0, 19, 18, 1, 0, 0, 0, 20, 21, 1, 0, 0, 0, 21, 19, 1, 0, 0, 0, 21, 22, 1, 0, 0, 0, 22, 6, 1, 0, 0, 0, 23, 25, 5, 13, 0, 0, 24, 23, 1, 0, 0, 0, 24, 25, 1, 0, 0, 0, 25, 26, 1, 0, 0, 0, 26, 27, 5, 10, 0, 0, 27, 8, 1, 0, 0, 0, 28, 30, 5, 34, 0, 0, 29, 31, 3, 3, 1, 0, 30, 29, 1, 0, 0, 0, 30, 31, 1, 0, 0, 0, 31, 37, 1, 0, 0, 0, 32, 33, 3, 5, 2, 0, 33, 34, 3, 3, 1, 0, 34, 36, 1, 0, 0, 0, 35, 32, 1, 0, 0, 0, 36, 39, 1, 0, 0, 0, 37, 35, 1, 0, 0, 0, 37, 38, 1, 0, 0, 0, 38, 41, 1, 0, 0, 0, 39, 37, 1, 0, 0, 0, 40, 42, 3, 5, 2, 0, 41, 40, 1, 0, 0, 0, 41, 42, 1, 0, 0, 0, 42, 44, 1, 0, 0, 0, 43, 45, 5, 34, 0, 0, 44, 43, 1, 0, 0, 0, 44, 45, 1, 0, 0, 0, 45, 10, 1, 0, 0, 0, 8, 0, 16, 21, 24, 30, 37, 41, 44, 0]

handlers/sshd_config/ast/parser/ConfigLexer.tokens

@@ -2,4 +2,5 @@ HASH=1
 WHITESPACE=2
 STRING=3
 NEWLINE=4
+QUOTED_STRING=5
 '#'=1

handlers/sshd_config/ast/parser/config_base_listener.go

@@ -56,3 +56,9 @@ func (s *BaseConfigListener) EnterLeadingComment(ctx *LeadingCommentContext) {}
 
 // ExitLeadingComment is called when production leadingComment is exited.
 func (s *BaseConfigListener) ExitLeadingComment(ctx *LeadingCommentContext) {}
+
+// EnterString is called when production string is entered.
+func (s *BaseConfigListener) EnterString(ctx *StringContext) {}
+
+// ExitString is called when production string is exited.
+func (s *BaseConfigListener) ExitString(ctx *StringContext) {}

handlers/sshd_config/ast/parser/config_lexer.go

@@ -46,25 +46,34 @@ func configlexerLexerInit() {
 		"", "'#'",
 	}
 	staticData.SymbolicNames = []string{
-		"", "HASH", "WHITESPACE", "STRING", "NEWLINE",
+		"", "HASH", "WHITESPACE", "STRING", "NEWLINE", "QUOTED_STRING",
 	}
 	staticData.RuleNames = []string{
-		"HASH", "WHITESPACE", "STRING", "NEWLINE",
+		"HASH", "WHITESPACE", "STRING", "NEWLINE", "QUOTED_STRING",
 	}
 	staticData.PredictionContextCache = antlr.NewPredictionContextCache()
 	staticData.serializedATN = []int32{
-		4, 0, 4, 26, 6, -1, 2, 0, 7, 0, 2, 1, 7, 1, 2, 2, 7, 2, 2, 3, 7, 3, 1,
+		4, 0, 5, 46, 6, -1, 2, 0, 7, 0, 2, 1, 7, 1, 2, 2, 7, 2, 2, 3, 7, 3, 2,
-		0, 1, 0, 1, 1, 4, 1, 13, 8, 1, 11, 1, 12, 1, 14, 1, 2, 4, 2, 18, 8, 2,
+		4, 7, 4, 1, 0, 1, 0, 1, 1, 4, 1, 15, 8, 1, 11, 1, 12, 1, 16, 1, 2, 4, 2,
-		11, 2, 12, 2, 19, 1, 3, 3, 3, 23, 8, 3, 1, 3, 1, 3, 0, 0, 4, 1, 1, 3, 2,
+		20, 8, 2, 11, 2, 12, 2, 21, 1, 3, 3, 3, 25, 8, 3, 1, 3, 1, 3, 1, 4, 1,
-		5, 3, 7, 4, 1, 0, 2, 2, 0, 9, 9, 32, 32, 4, 0, 9, 10, 13, 13, 32, 32, 35,
+		4, 3, 4, 31, 8, 4, 1, 4, 1, 4, 1, 4, 5, 4, 36, 8, 4, 10, 4, 12, 4, 39,
-		35, 28, 0, 1, 1, 0, 0, 0, 0, 3, 1, 0, 0, 0, 0, 5, 1, 0, 0, 0, 0, 7, 1,
+		9, 4, 1, 4, 3, 4, 42, 8, 4, 1, 4, 3, 4, 45, 8, 4, 0, 0, 5, 1, 1, 3, 2,
-		0, 0, 0, 1, 9, 1, 0, 0, 0, 3, 12, 1, 0, 0, 0, 5, 17, 1, 0, 0, 0, 7, 22,
+		5, 3, 7, 4, 9, 5, 1, 0, 2, 2, 0, 9, 9, 32, 32, 4, 0, 9, 10, 13, 13, 32,
-		1, 0, 0, 0, 9, 10, 5, 35, 0, 0, 10, 2, 1, 0, 0, 0, 11, 13, 7, 0, 0, 0,
+		32, 34, 35, 52, 0, 1, 1, 0, 0, 0, 0, 3, 1, 0, 0, 0, 0, 5, 1, 0, 0, 0, 0,
-		12, 11, 1, 0, 0, 0, 13, 14, 1, 0, 0, 0, 14, 12, 1, 0, 0, 0, 14, 15, 1,
+		7, 1, 0, 0, 0, 0, 9, 1, 0, 0, 0, 1, 11, 1, 0, 0, 0, 3, 14, 1, 0, 0, 0,
-		0, 0, 0, 15, 4, 1, 0, 0, 0, 16, 18, 8, 1, 0, 0, 17, 16, 1, 0, 0, 0, 18,
+		5, 19, 1, 0, 0, 0, 7, 24, 1, 0, 0, 0, 9, 28, 1, 0, 0, 0, 11, 12, 5, 35,
-		19, 1, 0, 0, 0, 19, 17, 1, 0, 0, 0, 19, 20, 1, 0, 0, 0, 20, 6, 1, 0, 0,
+		0, 0, 12, 2, 1, 0, 0, 0, 13, 15, 7, 0, 0, 0, 14, 13, 1, 0, 0, 0, 15, 16,
-		0, 21, 23, 5, 13, 0, 0, 22, 21, 1, 0, 0, 0, 22, 23, 1, 0, 0, 0, 23, 24,
+		1, 0, 0, 0, 16, 14, 1, 0, 0, 0, 16, 17, 1, 0, 0, 0, 17, 4, 1, 0, 0, 0,
-		1, 0, 0, 0, 24, 25, 5, 10, 0, 0, 25, 8, 1, 0, 0, 0, 4, 0, 14, 19, 22, 0,
+		18, 20, 8, 1, 0, 0, 19, 18, 1, 0, 0, 0, 20, 21, 1, 0, 0, 0, 21, 19, 1,
+		0, 0, 0, 21, 22, 1, 0, 0, 0, 22, 6, 1, 0, 0, 0, 23, 25, 5, 13, 0, 0, 24,
+		23, 1, 0, 0, 0, 24, 25, 1, 0, 0, 0, 25, 26, 1, 0, 0, 0, 26, 27, 5, 10,
+		0, 0, 27, 8, 1, 0, 0, 0, 28, 30, 5, 34, 0, 0, 29, 31, 3, 3, 1, 0, 30, 29,
+		1, 0, 0, 0, 30, 31, 1, 0, 0, 0, 31, 37, 1, 0, 0, 0, 32, 33, 3, 5, 2, 0,
+		33, 34, 3, 3, 1, 0, 34, 36, 1, 0, 0, 0, 35, 32, 1, 0, 0, 0, 36, 39, 1,
+		0, 0, 0, 37, 35, 1, 0, 0, 0, 37, 38, 1, 0, 0, 0, 38, 41, 1, 0, 0, 0, 39,
+		37, 1, 0, 0, 0, 40, 42, 3, 5, 2, 0, 41, 40, 1, 0, 0, 0, 41, 42, 1, 0, 0,
+		0, 42, 44, 1, 0, 0, 0, 43, 45, 5, 34, 0, 0, 44, 43, 1, 0, 0, 0, 44, 45,
+		1, 0, 0, 0, 45, 10, 1, 0, 0, 0, 8, 0, 16, 21, 24, 30, 37, 41, 44, 0,
 	}
 	deserializer := antlr.NewATNDeserializer(nil)
 	staticData.atn = deserializer.Deserialize(staticData.serializedATN)
@@ -105,8 +114,9 @@ func NewConfigLexer(input antlr.CharStream) *ConfigLexer {
 
 // ConfigLexer tokens.
 const (
-	ConfigLexerHASH       = 1
+	ConfigLexerHASH          = 1
-	ConfigLexerWHITESPACE = 2
+	ConfigLexerWHITESPACE    = 2
-	ConfigLexerSTRING     = 3
+	ConfigLexerSTRING        = 3
-	ConfigLexerNEWLINE    = 4
+	ConfigLexerNEWLINE       = 4
+	ConfigLexerQUOTED_STRING = 5
 )

handlers/sshd_config/ast/parser/config_listener.go

@@ -26,6 +26,9 @@ type ConfigListener interface {
 	// EnterLeadingComment is called when entering the leadingComment production.
 	EnterLeadingComment(c *LeadingCommentContext)
 
+	// EnterString is called when entering the string production.
+	EnterString(c *StringContext)
+
 	// ExitLineStatement is called when exiting the lineStatement production.
 	ExitLineStatement(c *LineStatementContext)
 
@@ -43,4 +46,7 @@ type ConfigListener interface {
 
 	// ExitLeadingComment is called when exiting the leadingComment production.
 	ExitLeadingComment(c *LeadingCommentContext)
+
+	// ExitString is called when exiting the string production.
+	ExitString(c *StringContext)
 }

handlers/sshd_config/ast/parser/config_parser.go

@@ -36,42 +36,44 @@ func configParserInit() {
 		"", "'#'",
 	}
 	staticData.SymbolicNames = []string{
-		"", "HASH", "WHITESPACE", "STRING", "NEWLINE",
+		"", "HASH", "WHITESPACE", "STRING", "NEWLINE", "QUOTED_STRING",
 	}
 	staticData.RuleNames = []string{
 		"lineStatement", "entry", "separator", "key", "value", "leadingComment",
+		"string",
 	}
 	staticData.PredictionContextCache = antlr.NewPredictionContextCache()
 	staticData.serializedATN = []int32{
-		4, 1, 4, 66, 2, 0, 7, 0, 2, 1, 7, 1, 2, 2, 7, 2, 2, 3, 7, 3, 2, 4, 7, 4,
+		4, 1, 5, 71, 2, 0, 7, 0, 2, 1, 7, 1, 2, 2, 7, 2, 2, 3, 7, 3, 2, 4, 7, 4,
-		2, 5, 7, 5, 1, 0, 1, 0, 1, 0, 3, 0, 16, 8, 0, 3, 0, 18, 8, 0, 1, 0, 1,
+		2, 5, 7, 5, 2, 6, 7, 6, 1, 0, 1, 0, 1, 0, 3, 0, 18, 8, 0, 3, 0, 20, 8,
-		0, 1, 1, 3, 1, 23, 8, 1, 1, 1, 3, 1, 26, 8, 1, 1, 1, 3, 1, 29, 8, 1, 1,
+		0, 1, 0, 1, 0, 1, 1, 3, 1, 25, 8, 1, 1, 1, 3, 1, 28, 8, 1, 1, 1, 3, 1,
-		1, 3, 1, 32, 8, 1, 1, 1, 3, 1, 35, 8, 1, 1, 2, 1, 2, 1, 3, 1, 3, 1, 4,
+		31, 8, 1, 1, 1, 3, 1, 34, 8, 1, 1, 1, 3, 1, 37, 8, 1, 1, 2, 1, 2, 1, 3,
-		1, 4, 5, 4, 43, 8, 4, 10, 4, 12, 4, 46, 9, 4, 1, 4, 3, 4, 49, 8, 4, 1,
+		1, 3, 1, 4, 1, 4, 1, 4, 5, 4, 46, 8, 4, 10, 4, 12, 4, 49, 9, 4, 1, 4, 3,
-		4, 3, 4, 52, 8, 4, 1, 5, 1, 5, 3, 5, 56, 8, 5, 1, 5, 1, 5, 3, 5, 60, 8,
+		4, 52, 8, 4, 1, 4, 3, 4, 55, 8, 4, 1, 5, 1, 5, 3, 5, 59, 8, 5, 1, 5, 1,
-		5, 4, 5, 62, 8, 5, 11, 5, 12, 5, 63, 1, 5, 0, 0, 6, 0, 2, 4, 6, 8, 10,
+		5, 3, 5, 63, 8, 5, 4, 5, 65, 8, 5, 11, 5, 12, 5, 66, 1, 6, 1, 6, 1, 6,
-		0, 0, 73, 0, 17, 1, 0, 0, 0, 2, 22, 1, 0, 0, 0, 4, 36, 1, 0, 0, 0, 6, 38,
+		0, 0, 7, 0, 2, 4, 6, 8, 10, 12, 0, 1, 2, 0, 3, 3, 5, 5, 77, 0, 19, 1, 0,
-		1, 0, 0, 0, 8, 44, 1, 0, 0, 0, 10, 53, 1, 0, 0, 0, 12, 18, 3, 2, 1, 0,
+		0, 0, 2, 24, 1, 0, 0, 0, 4, 38, 1, 0, 0, 0, 6, 40, 1, 0, 0, 0, 8, 47, 1,
-		13, 18, 3, 10, 5, 0, 14, 16, 5, 2, 0, 0, 15, 14, 1, 0, 0, 0, 15, 16, 1,
+		0, 0, 0, 10, 56, 1, 0, 0, 0, 12, 68, 1, 0, 0, 0, 14, 20, 3, 2, 1, 0, 15,
-		0, 0, 0, 16, 18, 1, 0, 0, 0, 17, 12, 1, 0, 0, 0, 17, 13, 1, 0, 0, 0, 17,
+		20, 3, 10, 5, 0, 16, 18, 5, 2, 0, 0, 17, 16, 1, 0, 0, 0, 17, 18, 1, 0,
-		15, 1, 0, 0, 0, 18, 19, 1, 0, 0, 0, 19, 20, 5, 0, 0, 1, 20, 1, 1, 0, 0,
+		0, 0, 18, 20, 1, 0, 0, 0, 19, 14, 1, 0, 0, 0, 19, 15, 1, 0, 0, 0, 19, 17,
-		0, 21, 23, 5, 2, 0, 0, 22, 21, 1, 0, 0, 0, 22, 23, 1, 0, 0, 0, 23, 25,
+		1, 0, 0, 0, 20, 21, 1, 0, 0, 0, 21, 22, 5, 0, 0, 1, 22, 1, 1, 0, 0, 0,
-		1, 0, 0, 0, 24, 26, 3, 6, 3, 0, 25, 24, 1, 0, 0, 0, 25, 26, 1, 0, 0, 0,
+		23, 25, 5, 2, 0, 0, 24, 23, 1, 0, 0, 0, 24, 25, 1, 0, 0, 0, 25, 27, 1,
-		26, 28, 1, 0, 0, 0, 27, 29, 3, 4, 2, 0, 28, 27, 1, 0, 0, 0, 28, 29, 1,
+		0, 0, 0, 26, 28, 3, 6, 3, 0, 27, 26, 1, 0, 0, 0, 27, 28, 1, 0, 0, 0, 28,
-		0, 0, 0, 29, 31, 1, 0, 0, 0, 30, 32, 3, 8, 4, 0, 31, 30, 1, 0, 0, 0, 31,
+		30, 1, 0, 0, 0, 29, 31, 3, 4, 2, 0, 30, 29, 1, 0, 0, 0, 30, 31, 1, 0, 0,
-		32, 1, 0, 0, 0, 32, 34, 1, 0, 0, 0, 33, 35, 3, 10, 5, 0, 34, 33, 1, 0,
+		0, 31, 33, 1, 0, 0, 0, 32, 34, 3, 8, 4, 0, 33, 32, 1, 0, 0, 0, 33, 34,
-		0, 0, 34, 35, 1, 0, 0, 0, 35, 3, 1, 0, 0, 0, 36, 37, 5, 2, 0, 0, 37, 5,
+		1, 0, 0, 0, 34, 36, 1, 0, 0, 0, 35, 37, 3, 10, 5, 0, 36, 35, 1, 0, 0, 0,
-		1, 0, 0, 0, 38, 39, 5, 3, 0, 0, 39, 7, 1, 0, 0, 0, 40, 41, 5, 3, 0, 0,
+		36, 37, 1, 0, 0, 0, 37, 3, 1, 0, 0, 0, 38, 39, 5, 2, 0, 0, 39, 5, 1, 0,
-		41, 43, 5, 2, 0, 0, 42, 40, 1, 0, 0, 0, 43, 46, 1, 0, 0, 0, 44, 42, 1,
+		0, 0, 40, 41, 3, 12, 6, 0, 41, 7, 1, 0, 0, 0, 42, 43, 3, 12, 6, 0, 43,
-		0, 0, 0, 44, 45, 1, 0, 0, 0, 45, 48, 1, 0, 0, 0, 46, 44, 1, 0, 0, 0, 47,
+		44, 5, 2, 0, 0, 44, 46, 1, 0, 0, 0, 45, 42, 1, 0, 0, 0, 46, 49, 1, 0, 0,
-		49, 5, 3, 0, 0, 48, 47, 1, 0, 0, 0, 48, 49, 1, 0, 0, 0, 49, 51, 1, 0, 0,
+		0, 47, 45, 1, 0, 0, 0, 47, 48, 1, 0, 0, 0, 48, 51, 1, 0, 0, 0, 49, 47,
-		0, 50, 52, 5, 2, 0, 0, 51, 50, 1, 0, 0, 0, 51, 52, 1, 0, 0, 0, 52, 9, 1,
+		1, 0, 0, 0, 50, 52, 3, 12, 6, 0, 51, 50, 1, 0, 0, 0, 51, 52, 1, 0, 0, 0,
-		0, 0, 0, 53, 55, 5, 1, 0, 0, 54, 56, 5, 2, 0, 0, 55, 54, 1, 0, 0, 0, 55,
+		52, 54, 1, 0, 0, 0, 53, 55, 5, 2, 0, 0, 54, 53, 1, 0, 0, 0, 54, 55, 1,
-		56, 1, 0, 0, 0, 56, 61, 1, 0, 0, 0, 57, 59, 5, 3, 0, 0, 58, 60, 5, 2, 0,
+		0, 0, 0, 55, 9, 1, 0, 0, 0, 56, 58, 5, 1, 0, 0, 57, 59, 5, 2, 0, 0, 58,
-		0, 59, 58, 1, 0, 0, 0, 59, 60, 1, 0, 0, 0, 60, 62, 1, 0, 0, 0, 61, 57,
+		57, 1, 0, 0, 0, 58, 59, 1, 0, 0, 0, 59, 64, 1, 0, 0, 0, 60, 62, 3, 12,
-		1, 0, 0, 0, 62, 63, 1, 0, 0, 0, 63, 61, 1, 0, 0, 0, 63, 64, 1, 0, 0, 0,
+		6, 0, 61, 63, 5, 2, 0, 0, 62, 61, 1, 0, 0, 0, 62, 63, 1, 0, 0, 0, 63, 65,
-		64, 11, 1, 0, 0, 0, 13, 15, 17, 22, 25, 28, 31, 34, 44, 48, 51, 55, 59,
+		1, 0, 0, 0, 64, 60, 1, 0, 0, 0, 65, 66, 1, 0, 0, 0, 66, 64, 1, 0, 0, 0,
-		63,
+		66, 67, 1, 0, 0, 0, 67, 11, 1, 0, 0, 0, 68, 69, 7, 0, 0, 0, 69, 13, 1,
+		0, 0, 0, 13, 17, 19, 24, 27, 30, 33, 36, 47, 51, 54, 58, 62, 66,
 	}
 	deserializer := antlr.NewATNDeserializer(nil)
 	staticData.atn = deserializer.Deserialize(staticData.serializedATN)
@@ -109,11 +111,12 @@ func NewConfigParser(input antlr.TokenStream) *ConfigParser {
 
 // ConfigParser tokens.
 const (
-	ConfigParserEOF        = antlr.TokenEOF
+	ConfigParserEOF           = antlr.TokenEOF
-	ConfigParserHASH       = 1
+	ConfigParserHASH          = 1
-	ConfigParserWHITESPACE = 2
+	ConfigParserWHITESPACE    = 2
-	ConfigParserSTRING     = 3
+	ConfigParserSTRING        = 3
-	ConfigParserNEWLINE    = 4
+	ConfigParserNEWLINE       = 4
+	ConfigParserQUOTED_STRING = 5
 )
 
 // ConfigParser rules.
@@ -124,6 +127,7 @@ const (
 	ConfigParserRULE_key            = 3
 	ConfigParserRULE_value          = 4
 	ConfigParserRULE_leadingComment = 5
+	ConfigParserRULE_string         = 6
 )
 
 // ILineStatementContext is an interface to support dynamic dispatch.
@@ -241,7 +245,7 @@ func (p *ConfigParser) LineStatement() (localctx ILineStatementContext) {
 	var _la int
 
 	p.EnterOuterAlt(localctx, 1)
-	p.SetState(17)
+	p.SetState(19)
 	p.GetErrorHandler().Sync(p)
 	if p.HasError() {
 		goto errorExit
@@ -250,18 +254,18 @@ func (p *ConfigParser) LineStatement() (localctx ILineStatementContext) {
 	switch p.GetInterpreter().AdaptivePredict(p.BaseParser, p.GetTokenStream(), 1, p.GetParserRuleContext()) {
 	case 1:
 		{
-			p.SetState(12)
+			p.SetState(14)
 			p.Entry()
 		}
 
 	case 2:
 		{
-			p.SetState(13)
+			p.SetState(15)
 			p.LeadingComment()
 		}
 
 	case 3:
-		p.SetState(15)
+		p.SetState(17)
 		p.GetErrorHandler().Sync(p)
 		if p.HasError() {
 			goto errorExit
@@ -270,7 +274,7 @@ func (p *ConfigParser) LineStatement() (localctx ILineStatementContext) {
 
 		if _la == ConfigParserWHITESPACE {
 			{
-				p.SetState(14)
+				p.SetState(16)
 				p.Match(ConfigParserWHITESPACE)
 				if p.HasError() {
 					// Recognition error - abort rule
@@ -284,7 +288,7 @@ func (p *ConfigParser) LineStatement() (localctx ILineStatementContext) {
 		goto errorExit
 	}
 	{
-		p.SetState(19)
+		p.SetState(21)
 		p.Match(ConfigParserEOF)
 		if p.HasError() {
 			// Recognition error - abort rule
@@ -449,12 +453,12 @@ func (p *ConfigParser) Entry() (localctx IEntryContext) {
 	var _la int
 
 	p.EnterOuterAlt(localctx, 1)
-	p.SetState(22)
+	p.SetState(24)
 	p.GetErrorHandler().Sync(p)
 
 	if p.GetInterpreter().AdaptivePredict(p.BaseParser, p.GetTokenStream(), 2, p.GetParserRuleContext()) == 1 {
 		{
-			p.SetState(21)
+			p.SetState(23)
 			p.Match(ConfigParserWHITESPACE)
 			if p.HasError() {
 				// Recognition error - abort rule
@@ -465,43 +469,43 @@ func (p *ConfigParser) Entry() (localctx IEntryContext) {
 	} else if p.HasError() { // JIM
 		goto errorExit
 	}
-	p.SetState(25)
+	p.SetState(27)
 	p.GetErrorHandler().Sync(p)
 
 	if p.GetInterpreter().AdaptivePredict(p.BaseParser, p.GetTokenStream(), 3, p.GetParserRuleContext()) == 1 {
 		{
-			p.SetState(24)
+			p.SetState(26)
 			p.Key()
 		}
 
 	} else if p.HasError() { // JIM
 		goto errorExit
 	}
-	p.SetState(28)
+	p.SetState(30)
 	p.GetErrorHandler().Sync(p)
 
 	if p.GetInterpreter().AdaptivePredict(p.BaseParser, p.GetTokenStream(), 4, p.GetParserRuleContext()) == 1 {
 		{
-			p.SetState(27)
+			p.SetState(29)
 			p.Separator()
 		}
 
 	} else if p.HasError() { // JIM
 		goto errorExit
 	}
-	p.SetState(31)
+	p.SetState(33)
 	p.GetErrorHandler().Sync(p)
 
 	if p.GetInterpreter().AdaptivePredict(p.BaseParser, p.GetTokenStream(), 5, p.GetParserRuleContext()) == 1 {
 		{
-			p.SetState(30)
+			p.SetState(32)
 			p.Value()
 		}
 
 	} else if p.HasError() { // JIM
 		goto errorExit
 	}
-	p.SetState(34)
+	p.SetState(36)
 	p.GetErrorHandler().Sync(p)
 	if p.HasError() {
 		goto errorExit
@@ -510,7 +514,7 @@ func (p *ConfigParser) Entry() (localctx IEntryContext) {
 
 	if _la == ConfigParserHASH {
 		{
-			p.SetState(33)
+			p.SetState(35)
 			p.LeadingComment()
 		}
 
@@ -604,7 +608,7 @@ func (p *ConfigParser) Separator() (localctx ISeparatorContext) {
 	p.EnterRule(localctx, 4, ConfigParserRULE_separator)
 	p.EnterOuterAlt(localctx, 1)
 	{
-		p.SetState(36)
+		p.SetState(38)
 		p.Match(ConfigParserWHITESPACE)
 		if p.HasError() {
 			// Recognition error - abort rule
@@ -633,7 +637,7 @@ type IKeyContext interface {
 	GetParser() antlr.Parser
 
 	// Getter signatures
-	STRING() antlr.TerminalNode
+	String_() IStringContext
 
 	// IsKeyContext differentiates from other interfaces.
 	IsKeyContext()
@@ -671,8 +675,20 @@ func NewKeyContext(parser antlr.Parser, parent antlr.ParserRuleContext, invoking
 
 func (s *KeyContext) GetParser() antlr.Parser { return s.parser }
 
-func (s *KeyContext) STRING() antlr.TerminalNode {
+func (s *KeyContext) String_() IStringContext {
-	return s.GetToken(ConfigParserSTRING, 0)
+	var t antlr.RuleContext
+	for _, ctx := range s.GetChildren() {
+		if _, ok := ctx.(IStringContext); ok {
+			t = ctx.(antlr.RuleContext)
+			break
+		}
+	}
+
+	if t == nil {
+		return nil
+	}
+
+	return t.(IStringContext)
 }
 
 func (s *KeyContext) GetRuleContext() antlr.RuleContext {
@@ -700,12 +716,8 @@ func (p *ConfigParser) Key() (localctx IKeyContext) {
 	p.EnterRule(localctx, 6, ConfigParserRULE_key)
 	p.EnterOuterAlt(localctx, 1)
 	{
-		p.SetState(38)
+		p.SetState(40)
-		p.Match(ConfigParserSTRING)
+		p.String_()
-		if p.HasError() {
-			// Recognition error - abort rule
-			goto errorExit
-		}
 	}
 
 errorExit:
@@ -729,8 +741,8 @@ type IValueContext interface {
 	GetParser() antlr.Parser
 
 	// Getter signatures
-	AllSTRING() []antlr.TerminalNode
+	AllString_() []IStringContext
-	STRING(i int) antlr.TerminalNode
+	String_(i int) IStringContext
 	AllWHITESPACE() []antlr.TerminalNode
 	WHITESPACE(i int) antlr.TerminalNode
 
@@ -770,12 +782,45 @@ func NewValueContext(parser antlr.Parser, parent antlr.ParserRuleContext, invoki
 
 func (s *ValueContext) GetParser() antlr.Parser { return s.parser }
 
-func (s *ValueContext) AllSTRING() []antlr.TerminalNode {
+func (s *ValueContext) AllString_() []IStringContext {
-	return s.GetTokens(ConfigParserSTRING)
+	children := s.GetChildren()
+	len := 0
+	for _, ctx := range children {
+		if _, ok := ctx.(IStringContext); ok {
+			len++
+		}
+	}
+
+	tst := make([]IStringContext, len)
+	i := 0
+	for _, ctx := range children {
+		if t, ok := ctx.(IStringContext); ok {
+			tst[i] = t.(IStringContext)
+			i++
+		}
+	}
+
+	return tst
 }
 
-func (s *ValueContext) STRING(i int) antlr.TerminalNode {
+func (s *ValueContext) String_(i int) IStringContext {
-	return s.GetToken(ConfigParserSTRING, i)
+	var t antlr.RuleContext
+	j := 0
+	for _, ctx := range s.GetChildren() {
+		if _, ok := ctx.(IStringContext); ok {
+			if j == i {
+				t = ctx.(antlr.RuleContext)
+				break
+			}
+			j++
+		}
+	}
+
+	if t == nil {
+		return nil
+	}
+
+	return t.(IStringContext)
 }
 
 func (s *ValueContext) AllWHITESPACE() []antlr.TerminalNode {
@@ -814,7 +859,7 @@ func (p *ConfigParser) Value() (localctx IValueContext) {
 	var _alt int
 
 	p.EnterOuterAlt(localctx, 1)
-	p.SetState(44)
+	p.SetState(47)
 	p.GetErrorHandler().Sync(p)
 	if p.HasError() {
 		goto errorExit
@@ -826,15 +871,11 @@ func (p *ConfigParser) Value() (localctx IValueContext) {
 	for _alt != 2 && _alt != antlr.ATNInvalidAltNumber {
 		if _alt == 1 {
 			{
-				p.SetState(40)
+				p.SetState(42)
-				p.Match(ConfigParserSTRING)
+				p.String_()
-				if p.HasError() {
-					// Recognition error - abort rule
-					goto errorExit
-				}
 			}
 			{
-				p.SetState(41)
+				p.SetState(43)
 				p.Match(ConfigParserWHITESPACE)
 				if p.HasError() {
 					// Recognition error - abort rule
@@ -843,7 +884,7 @@ func (p *ConfigParser) Value() (localctx IValueContext) {
 			}
 
 		}
-		p.SetState(46)
+		p.SetState(49)
 		p.GetErrorHandler().Sync(p)
 		if p.HasError() {
 			goto errorExit
@@ -853,25 +894,21 @@ func (p *ConfigParser) Value() (localctx IValueContext) {
 			goto errorExit
 		}
 	}
-	p.SetState(48)
+	p.SetState(51)
 	p.GetErrorHandler().Sync(p)
 	if p.HasError() {
 		goto errorExit
 	}
 	_la = p.GetTokenStream().LA(1)
 
-	if _la == ConfigParserSTRING {
+	if _la == ConfigParserSTRING || _la == ConfigParserQUOTED_STRING {
 		{
-			p.SetState(47)
+			p.SetState(50)
-			p.Match(ConfigParserSTRING)
+			p.String_()
-			if p.HasError() {
-				// Recognition error - abort rule
-				goto errorExit
-			}
 		}
 
 	}
-	p.SetState(51)
+	p.SetState(54)
 	p.GetErrorHandler().Sync(p)
 	if p.HasError() {
 		goto errorExit
@@ -880,7 +917,7 @@ func (p *ConfigParser) Value() (localctx IValueContext) {
 
 	if _la == ConfigParserWHITESPACE {
 		{
-			p.SetState(50)
+			p.SetState(53)
 			p.Match(ConfigParserWHITESPACE)
 			if p.HasError() {
 				// Recognition error - abort rule
@@ -914,8 +951,8 @@ type ILeadingCommentContext interface {
 	HASH() antlr.TerminalNode
 	AllWHITESPACE() []antlr.TerminalNode
 	WHITESPACE(i int) antlr.TerminalNode
-	AllSTRING() []antlr.TerminalNode
+	AllString_() []IStringContext
-	STRING(i int) antlr.TerminalNode
+	String_(i int) IStringContext
 
 	// IsLeadingCommentContext differentiates from other interfaces.
 	IsLeadingCommentContext()
@@ -965,12 +1002,45 @@ func (s *LeadingCommentContext) WHITESPACE(i int) antlr.TerminalNode {
 	return s.GetToken(ConfigParserWHITESPACE, i)
 }
 
-func (s *LeadingCommentContext) AllSTRING() []antlr.TerminalNode {
+func (s *LeadingCommentContext) AllString_() []IStringContext {
-	return s.GetTokens(ConfigParserSTRING)
+	children := s.GetChildren()
+	len := 0
+	for _, ctx := range children {
+		if _, ok := ctx.(IStringContext); ok {
+			len++
+		}
+	}
+
+	tst := make([]IStringContext, len)
+	i := 0
+	for _, ctx := range children {
+		if t, ok := ctx.(IStringContext); ok {
+			tst[i] = t.(IStringContext)
+			i++
+		}
+	}
+
+	return tst
 }
 
-func (s *LeadingCommentContext) STRING(i int) antlr.TerminalNode {
+func (s *LeadingCommentContext) String_(i int) IStringContext {
-	return s.GetToken(ConfigParserSTRING, i)
+	var t antlr.RuleContext
+	j := 0
+	for _, ctx := range s.GetChildren() {
+		if _, ok := ctx.(IStringContext); ok {
+			if j == i {
+				t = ctx.(antlr.RuleContext)
+				break
+			}
+			j++
+		}
+	}
+
+	if t == nil {
+		return nil
+	}
+
+	return t.(IStringContext)
 }
 
 func (s *LeadingCommentContext) GetRuleContext() antlr.RuleContext {
@@ -1000,14 +1070,14 @@ func (p *ConfigParser) LeadingComment() (localctx ILeadingCommentContext) {
 
 	p.EnterOuterAlt(localctx, 1)
 	{
-		p.SetState(53)
+		p.SetState(56)
 		p.Match(ConfigParserHASH)
 		if p.HasError() {
 			// Recognition error - abort rule
 			goto errorExit
 		}
 	}
-	p.SetState(55)
+	p.SetState(58)
 	p.GetErrorHandler().Sync(p)
 	if p.HasError() {
 		goto errorExit
@@ -1016,7 +1086,7 @@ func (p *ConfigParser) LeadingComment() (localctx ILeadingCommentContext) {
 
 	if _la == ConfigParserWHITESPACE {
 		{
-			p.SetState(54)
+			p.SetState(57)
 			p.Match(ConfigParserWHITESPACE)
 			if p.HasError() {
 				// Recognition error - abort rule
@@ -1025,23 +1095,19 @@ func (p *ConfigParser) LeadingComment() (localctx ILeadingCommentContext) {
 		}
 
 	}
-	p.SetState(61)
+	p.SetState(64)
 	p.GetErrorHandler().Sync(p)
 	if p.HasError() {
 		goto errorExit
 	}
 	_la = p.GetTokenStream().LA(1)
 
-	for ok := true; ok; ok = _la == ConfigParserSTRING {
+	for ok := true; ok; ok = _la == ConfigParserSTRING || _la == ConfigParserQUOTED_STRING {
 		{
-			p.SetState(57)
+			p.SetState(60)
-			p.Match(ConfigParserSTRING)
+			p.String_()
-			if p.HasError() {
-				// Recognition error - abort rule
-				goto errorExit
-			}
 		}
-		p.SetState(59)
+		p.SetState(62)
 		p.GetErrorHandler().Sync(p)
 		if p.HasError() {
 			goto errorExit
@@ -1050,7 +1116,7 @@ func (p *ConfigParser) LeadingComment() (localctx ILeadingCommentContext) {
 
 		if _la == ConfigParserWHITESPACE {
 			{
-				p.SetState(58)
+				p.SetState(61)
 				p.Match(ConfigParserWHITESPACE)
 				if p.HasError() {
 					// Recognition error - abort rule
@@ -1060,7 +1126,7 @@ func (p *ConfigParser) LeadingComment() (localctx ILeadingCommentContext) {
 
 		}
 
-		p.SetState(63)
+		p.SetState(66)
 		p.GetErrorHandler().Sync(p)
 		if p.HasError() {
 			goto errorExit
@@ -1080,3 +1146,109 @@ errorExit:
 	return localctx
 	goto errorExit // Trick to prevent compiler error if the label is not used
 }
+
+// IStringContext is an interface to support dynamic dispatch.
+type IStringContext interface {
+	antlr.ParserRuleContext
+
+	// GetParser returns the parser.
+	GetParser() antlr.Parser
+
+	// Getter signatures
+	QUOTED_STRING() antlr.TerminalNode
+	STRING() antlr.TerminalNode
+
+	// IsStringContext differentiates from other interfaces.
+	IsStringContext()
+}
+
+type StringContext struct {
+	antlr.BaseParserRuleContext
+	parser antlr.Parser
+}
+
+func NewEmptyStringContext() *StringContext {
+	var p = new(StringContext)
+	antlr.InitBaseParserRuleContext(&p.BaseParserRuleContext, nil, -1)
+	p.RuleIndex = ConfigParserRULE_string
+	return p
+}
+
+func InitEmptyStringContext(p *StringContext) {
+	antlr.InitBaseParserRuleContext(&p.BaseParserRuleContext, nil, -1)
+	p.RuleIndex = ConfigParserRULE_string
+}
+
+func (*StringContext) IsStringContext() {}
+
+func NewStringContext(parser antlr.Parser, parent antlr.ParserRuleContext, invokingState int) *StringContext {
+	var p = new(StringContext)
+
+	antlr.InitBaseParserRuleContext(&p.BaseParserRuleContext, parent, invokingState)
+
+	p.parser = parser
+	p.RuleIndex = ConfigParserRULE_string
+
+	return p
+}
+
+func (s *StringContext) GetParser() antlr.Parser { return s.parser }
+
+func (s *StringContext) QUOTED_STRING() antlr.TerminalNode {
+	return s.GetToken(ConfigParserQUOTED_STRING, 0)
+}
+
+func (s *StringContext) STRING() antlr.TerminalNode {
+	return s.GetToken(ConfigParserSTRING, 0)
+}
+
+func (s *StringContext) GetRuleContext() antlr.RuleContext {
+	return s
+}
+
+func (s *StringContext) ToStringTree(ruleNames []string, recog antlr.Recognizer) string {
+	return antlr.TreesStringTree(s, ruleNames, recog)
+}
+
+func (s *StringContext) EnterRule(listener antlr.ParseTreeListener) {
+	if listenerT, ok := listener.(ConfigListener); ok {
+		listenerT.EnterString(s)
+	}
+}
+
+func (s *StringContext) ExitRule(listener antlr.ParseTreeListener) {
+	if listenerT, ok := listener.(ConfigListener); ok {
+		listenerT.ExitString(s)
+	}
+}
+
+func (p *ConfigParser) String_() (localctx IStringContext) {
+	localctx = NewStringContext(p, p.GetParserRuleContext(), p.GetState())
+	p.EnterRule(localctx, 12, ConfigParserRULE_string)
+	var _la int
+
+	p.EnterOuterAlt(localctx, 1)
+	{
+		p.SetState(68)
+		_la = p.GetTokenStream().LA(1)
+
+		if !(_la == ConfigParserSTRING || _la == ConfigParserQUOTED_STRING) {
+			p.GetErrorHandler().RecoverInline(p)
+		} else {
+			p.GetErrorHandler().ReportMatch(p)
+			p.Consume()
+		}
+	}
+
+errorExit:
+	if p.HasError() {
+		v := p.GetError()
+		localctx.SetException(v)
+		p.GetErrorHandler().ReportError(p, v)
+		p.GetErrorHandler().Recover(p, v)
+		p.SetError(nil)
+	}
+	p.ExitRule()
+	return localctx
+	goto errorExit // Trick to prevent compiler error if the label is not used
+}

handlers/sshd_config/ast/parser_test.go

@@ -165,7 +165,7 @@ func TestIncompleteMatchBlock(
 		t.Errorf("Expected first entry to be 'User lena', but got: %v", matchBlock.MatchValue.Entries[0])
 	}
 
-	if !(matchBlock.MatchValue.Entries[1].Value.Value == "User " && matchBlock.MatchValue.Entries[1].Criteria.Type == "User" && matchBlock.MatchValue.Entries[1].Values == nil) {
+	if !(matchBlock.MatchValue.Entries[1].Value.Value == "User " && matchBlock.MatchValue.Entries[1].Criteria.Type == "User" && len(matchBlock.MatchValue.Entries[1].Values.Values) == 0) {
 		t.Errorf("Expected second entry to be 'User ', but got: %v", matchBlock.MatchValue.Entries[1])
 	}
 }
@@ -544,3 +544,101 @@ Match Address 172.22.100.0/24,172.22.5.0/24,127.0.0.1
 		t.Errorf("Expected seventh entry to be 'PermitRootLogin without-password', but got: %v", seventhEntry.Value)
 	}
 }
+
+func TestQuotedOptionExample(
+	t *testing.T,
+) {
+	input := utils.Dedent(`
+PermitRootLogin "no"
+`)
+	p := NewSSHConfig()
+	errors := p.Parse(input)
+
+	if len(errors) != 0 {
+		t.Fatalf("Expected no errors, got %v", errors)
+	}
+
+	if !(p.Options.Size() == 1 &&
+		len(utils.KeysOfMap(p.CommentLines)) == 0) {
+		t.Errorf("Expected 1 option and no comment lines, but got: %v, %v", p.Options, p.CommentLines)
+	}
+
+	rawFirstEntry, _ := p.Options.Get(uint32(0))
+	entry := rawFirstEntry.(*SSHDOption)
+
+	if !(entry.Key.Value.Value == "PermitRootLogin" && entry.OptionValue.Value.Value == "no") {
+		t.Errorf("Expected first entry to be 'PermitRootLogin no', but got: %v", entry.Value)
+	}
+
+	if !(entry.LocationRange.Start.Line == 0 && entry.LocationRange.Start.Character == 0 && entry.LocationRange.End.Line == 0 && entry.LocationRange.End.Character == 20) {
+		t.Errorf("Expected location range to be 0:0-0:20, but got: %v", entry.LocationRange)
+	}
+
+	if !(entry.OptionValue.LocationRange.Start.Character == 16 && entry.OptionValue.LocationRange.End.Character == 20) {
+		t.Errorf("Expected option value location range to be 17-20, but got: %v", entry.OptionValue.LocationRange)
+	}
+}
+
+func TestQuotedKeyExample(
+	t *testing.T,
+) {
+	input := utils.Dedent(`
+"PermitRootLogin" no
+`)
+	p := NewSSHConfig()
+	errors := p.Parse(input)
+
+	if len(errors) != 0 {
+		t.Fatalf("Expected no errors, got %v", errors)
+	}
+
+	if !(p.Options.Size() == 1 &&
+		len(utils.KeysOfMap(p.CommentLines)) == 0) {
+		t.Errorf("Expected 1 option and no comment lines, but got: %v, %v", p.Options, p.CommentLines)
+	}
+
+	rawFirstEntry, _ := p.Options.Get(uint32(0))
+	entry := rawFirstEntry.(*SSHDOption)
+
+	if !(entry.Key.Value.Value == "PermitRootLogin" && entry.OptionValue.Value.Value == "no") {
+		t.Errorf("Expected first entry to be 'PermitRootLogin no', but got: %v", entry.Value)
+	}
+
+	if !(entry.LocationRange.Start.Line == 0 && entry.LocationRange.Start.Character == 0 && entry.LocationRange.End.Line == 0 && entry.LocationRange.End.Character == 20) {
+		t.Errorf("Expected location range to be 0:0-0:20, but got: %v", entry.LocationRange)
+	}
+
+	if !(entry.Key.LocationRange.Start.Character == 0 && entry.Key.LocationRange.End.Character == 17) {
+		t.Errorf("Expected key location range to be 0-17, but got: %v", entry.Key.LocationRange)
+	}
+
+	if !(entry.Key.LocationRange.Start.Character == 0 && entry.Key.LocationRange.End.Character == 17) {
+		t.Errorf("Expected key location range to be 0-17, but got: %v", entry.Key.LocationRange)
+	}
+}
+
+func TestQuotedValueWithSpacesExample(
+	t *testing.T,
+) {
+	input := utils.Dedent(`
+PermitRootLogin "no yes maybe"
+`)
+	p := NewSSHConfig()
+	errors := p.Parse(input)
+
+	if len(errors) != 0 {
+		t.Fatalf("Expected no errors, got %v", errors)
+	}
+
+	if !(p.Options.Size() == 1 &&
+		len(utils.KeysOfMap(p.CommentLines)) == 0) {
+		t.Errorf("Expected 1 option and no comment lines, but got: %v, %v", p.Options, p.CommentLines)
+	}
+
+	rawFirstEntry, _ := p.Options.Get(uint32(0))
+	entry := rawFirstEntry.(*SSHDOption)
+
+	if !(entry.Key.Value.Value == "PermitRootLogin" && entry.OptionValue.Value.Value == "no yes maybe") {
+		t.Errorf("Expected first entry to be 'PermitRootLogin no yes maybe', but got: %v", entry.Value)
+	}
+}

handlers/sshd_config/ast/sshd_config.go

@@ -33,6 +33,7 @@ type SSHDEntry interface {
 
 type SSHDSeparator struct {
 	common.LocationRange
+	Value commonparser.ParsedString
 }
 
 type SSHDOption struct {

handlers/sshd_config/fields/match-parser/parser_test.go

@@ -128,7 +128,7 @@ func TestIncompleteBetweenValuesExample(
 		t.Errorf("Expected User, but got %v", match.Entries[0])
 	}
 
-	if !(match.Entries[0].Values == nil) {
+	if !(len(match.Entries[0].Values.Values) == 0) {
 		t.Errorf("Expected 0 values, but got %v", match.Entries[0].Values)
 	}
 }

handlers/sshd_config/handlers/completions.go

@@ -22,16 +22,20 @@ func GetRootCompletions(
 
 	if parentMatchBlock == nil {
 		for key, option := range fields.Options {
-			if _, found := d.Indexes.AllOptionsPerName[key]; !found {
+			if d.Indexes != nil && utils.KeyExists(d.Indexes.AllOptionsPerName, key) && !utils.KeyExists(fields.AllowedDuplicateOptions, key) {
-				availableOptions[key] = option
+				continue
 			}
+
+			availableOptions[key] = option
 		}
 	} else {
 		for key := range fields.MatchAllowedOptions {
 			if option, found := fields.Options[key]; found {
-				if _, found := d.Indexes.AllOptionsPerName[key]; !found {
+				if d.Indexes != nil && utils.KeyExists(d.Indexes.AllOptionsPerName, key) && !utils.KeyExists(fields.AllowedDuplicateOptions, key) {
-					availableOptions[key] = option
+					continue
 				}
+
+				availableOptions[key] = option
 			}
 		}
 	}

handlers/sshd_config/lsp/text-document-completion.go

@@ -33,7 +33,7 @@ func TextDocumentCompletion(context *glsp.Context, params *protocol.CompletionPa
 			d,
 			matchBlock,
 			// Empty line, or currently typing a new key
-			entry == nil || isEmptyPattern.Match([]byte(entry.Value.Value[cursor:])),
+			entry == nil || isEmptyPattern.Match([]byte(entry.Value.Raw[cursor:])),
 		)
 	}
 

handlers/sshd_config/test_utils/input.go

@@ -0,0 +1,33 @@
+package testutils_test
+
+import (
+	sshdconfig "config-lsp/handlers/sshd_config"
+	"config-lsp/handlers/sshd_config/ast"
+	"config-lsp/handlers/sshd_config/indexes"
+	"config-lsp/utils"
+	"testing"
+)
+
+func DocumentFromInput(
+	t *testing.T,
+	content string,
+) *sshdconfig.SSHDocument {
+	input := utils.Dedent(content)
+	c := ast.NewSSHConfig()
+	errors := c.Parse(input)
+
+	if len(errors) > 0 {
+		t.Fatalf("Parse error: %v", errors)
+	}
+
+	i, errors := indexes.CreateIndexes(*c)
+
+	if len(errors) > 0 {
+		t.Fatalf("Index error: %v", errors)
+	}
+
+	return &sshdconfig.SSHDocument{
+		Config:  c,
+		Indexes: i,
+	}
+}