auth.go

package core

import (
	"bytes"
	"context"
	"encoding/base64"
	"errors"
	"fmt"
	"math"
	"net"
	"net/http"
	"reflect"
	"sort"
	"strconv"
	"strings"
	"sync"

	"github.com/croessner/nauthilus/server/backend"
	"github.com/croessner/nauthilus/server/config"
	errors2 "github.com/croessner/nauthilus/server/errors"
	"github.com/croessner/nauthilus/server/global"
	"github.com/croessner/nauthilus/server/localcache"
	"github.com/croessner/nauthilus/server/logging"
	"github.com/croessner/nauthilus/server/lualib"
	"github.com/croessner/nauthilus/server/lualib/action"
	"github.com/croessner/nauthilus/server/lualib/filter"
	"github.com/croessner/nauthilus/server/rediscli"
	"github.com/croessner/nauthilus/server/stats"
	"github.com/croessner/nauthilus/server/util"
	"github.com/gin-gonic/gin"
	"github.com/go-kit/log/level"
	"github.com/go-webauthn/webauthn/webauthn"
	openapi "github.com/ory/hydra-client-go/v2"
	"github.com/prometheus/client_golang/prometheus"
)

// ClaimHandler represents a claim handler struct.
// A claim handler in this context is something to work with JSON Web Tokens (JWT), often used for APIs.
type ClaimHandler struct {
	// Type is the reflected Kind of the claim value.
	Type reflect.Kind

	// ApplyFunc is a function that takes in three parameters: the claim value, the map of claims and the claim key.
	// The function is intended to apply some process on the claim using the provided parameters,
	// and return a boolean result.
	ApplyFunc func(value any, claims map[string]any, claimKey string) bool
}

// BackendServer represents a type for managing a slive of config.BackendServer
type BackendServer struct {
	// backendServer is a slice of pointers to config.BackendServer objects
	backendServer []*config.BackendServer

	// mu provides a read/write mutex for thread-safe operations on the backendServer
	mu sync.RWMutex
}

// Update updates the backendServer field of the BackendServer object with the provided servers slice.
func (n *BackendServer) Update(servers []*config.BackendServer) {
	n.mu.Lock()

	defer n.mu.Unlock()

	n.backendServer = servers
}

func (n *BackendServer) GetTotalServers() int {
	n.mu.RLock()

	defer n.mu.RUnlock()

	return len(n.backendServer)
}

// NewBackendServer creates a new instance of the BackendServer struct.
// It returns a pointer to the newly created BackendServer.
func NewBackendServer() *BackendServer {
	return &BackendServer{}
}

// JSONRequest is a data structure containing the details of a client's request in JSON format.
type JSONRequest struct {
	// Username is the identifier of the client/user sending the request.
	Username string `json:"username"`

	// Password is the authentication credential of the client/user sending the request.
	Password string `json:"password"`

	// ClientIP is the IP address of the client/user making the request.
	ClientIP string `json:"client_ip"`

	// ClientPort is the port number from which the client/user is sending the request.
	ClientPort string `json:"client_port"`

	// ClientHostname is the hostname of the client which is sending the request.
	ClientHostname string `json:"client_hostname"`

	// ClientID is the unique identifier of the client/user, usually assigned by the application.
	ClientID string `json:"client_id"`

	// LocalIP is the IP address of the server or endpoint receiving the request.
	LocalIP string `json:"local_ip"`

	// LocalPort is the port number of the server or endpoint receiving the request.
	LocalPort string `json:"local_port"`

	// Service is the specific service that the client/user is trying to access with the request.
	Service string `json:"service"`

	// Method is the HTTP method used in the request (i.e., PLAIN, LOGIN, etc.)
	Method string `json:"method"`

	// AuthLoginAttempt is a flag indicating if the request is an attempt to authenticate (login). This is expressed as an unsigned integer where applicable flags/types are usually interpreted from the application's specific logic.
	AuthLoginAttempt uint `json:"auth_login_attempt"`
}

// Authentication represents a struct that holds information related to authentication process.
type Authentication struct {
	// UsernameReplace is a flag that is set, if a user was found in a Database.
	UsernameReplace bool

	// NoAuth is a flag that is set, if the request mode does not require authentication.
	NoAuth bool

	// ListAccounts is a flag that is set, if Nauthilus is requested to send a full list of available user accounts.
	ListAccounts bool

	// UserFound is a flag that is set, if a password Database found the user.
	UserFound bool

	// PasswordsAccountSeen is a counter that is increased whenever a new failed password was detected for the current account.
	PasswordsAccountSeen uint

	// PasswordsTotalSeen is a counter that is increased whenever a new failed password was detected.
	PasswordsTotalSeen uint

	// LoginAttempts is a counter that is incremented for each failed login request
	LoginAttempts uint

	// StatusCodeOk is the HTTP status code that is set by setStatusCodes.
	StatusCodeOK int

	// StatusCodeInternalError is the HTTP status code that is set by setStatusCodes.
	StatusCodeInternalError int

	// StatusCodeFail is the HTTP status code that is set by setStatusCodes.
	StatusCodeFail int

	// GUID is a global unique identifier that is inherited in all functions and methods that deal with the
	// authentication process. It is needed to track log lines belonging to one request.
	GUID *string

	// Method is set by the "Auth-Method" HTTP request header (Nginx protocol). It is typically something like "plain"
	// or "login".
	Method *string

	// AccountField is the name of either a SQL field name or an LDAP attribute that was used to retrieve a user account.
	AccountField *string

	// Username is the value that was taken from the HTTP header "Auth-User" (Nginx protocol).
	Username string

	// UsernameOrig is a copy from the username that was set by the HTTP request header "Auth-User" (Nginx protocol).
	UsernameOrig string

	// Password is the value that was taken from the HTTP header "Auth-Pass" (Nginx protocol).
	Password string

	// ClientIP is the IP of a client that is to be authenticated. The value is set by the HTTP request header
	// "Client-IP" (Nginx protocol).
	ClientIP string

	// XClientPort adds the remote client TCP port, which is set by the HTTP request header "X-Client-Port".
	XClientPort string

	// ClientHost is the DNS A name of the remote client. It is set with the HTTP request header "Client-Host" (Nginx
	// protocol).
	ClientHost string

	// HAProxy specific headers
	XSSL                string // %[ssl_fc]
	XSSLSessionID       string // %[ssl_fc_session_id,hex]
	XSSLClientVerify    string // %[ssl_c_verify]
	XSSLClientDN        string // %{+Q}[ssl_c_s_dn]
	XSSLClientCN        string // %{+Q}[ssl_c_s_dn(cn)]
	XSSLIssuer          string // %{+Q}[ssl_c_i_dn]
	XSSLClientNotBefore string // %{+Q}[ssl_c_notbefore]
	XSSLClientNotAfter  string // %{+Q}[ssl_c_notafter]
	XSSLSubjectDN       string // %{+Q}[ssl_c_s_dn]
	XSSLIssuerDN        string // %{+Q}[ssl_c_i_dn]
	XSSLClientSubjectDN string // %{+Q}[ssl_c_s_dn]
	XSSLClientIssuerDN  string // %{+Q}[ssl_c_i_dn]
	XSSLProtocol        string // %[ssl_fc_protocol]
	XSSLCipher          string // %[ssl_fc_cipher]

	// XClientID is delivered by some mail user agents when using IMAP. This value is set by the HTTP request header
	// "X-Client-Id".
	XClientID string

	// XLocalIP is the TCP/IP address of the server that asks for authentication. Its value is set by the HTTP request
	// header "X-Local-IP".
	XLocalIP string

	// XPort is the TCP port of the server that asks for authentication. Its value is set by the HTTP request
	// header "X-Local-Port".
	XPort string

	// UserAgent may have been seent by a mail user agent and is set by the HTTP request header "User-Agent".
	UserAgent *string

	// StatusMessage is the HTTP response payload that is sent to the remote server that asked for authentication.
	StatusMessage string

	// Service is set by Nauthilus depending on the router endpoint. Look at httpQueryHandler for the structure of available
	// endpoints.
	Service string

	// BruteForceName is the canonical name of a brute force bucket that was triggered by a rule.
	BruteForceName string

	// FeatureName is the name of a feature that has triggered a reject.
	FeatureName string

	// TOTPSecret is used to store a TOTP secret in a SQL Database.
	TOTPSecret *string

	// TOTPSecretField is the SQL field or LDAP attribute that resolves the TOTP secret for two-factor authentication.
	TOTPSecretField *string

	// TOTPRecoveryField NYI
	TOTPRecoveryField *string

	// UniqueUserIDField is a string representing a unique user identifier.
	UniqueUserIDField *string

	// DisplayNameField is the display name of a user
	DisplayNameField *string

	// AdditionalLogging is a slice of strings that can be filled from Lua features and a Lua backend. Its result will be
	// added to the regular log lines.
	AdditionalLogs []any

	// BruteForceCounter is a map that increments failed login requests. The key is a rule name defined in the
	// configuration file.
	BruteForceCounter map[string]uint

	// SourcePassDBBackend is a marker for the Database that is responsible for a specific user. It is set by the
	// password Database and stored in Redis to track the authentication flow accross databases (including proxy).
	SourcePassDBBackend global.Backend

	// UsedPassDBBackend is set by the password Database that answered the current authentication request.
	UsedPassDBBackend global.Backend

	// UsedBackendIP is set by a filter Lua script for the Nginx endpoint to set the HTTP response header 'Auth-Server'.
	UsedBackendIP string

	// UsedBackendPort is set by a filter Lua script for the Nginx endpoint to set the HTTP response header 'Auth-Port'.
	UsedBackendPort int

	// Attributes is a result container for SQL and LDAP queries. Databases store their result by using a field or
	// attribute name as key and the corresponding result as value.
	Attributes backend.DatabaseResult

	// Protocol is set by the HTTP request header "Auth-Protocol" (Nginx protocol).
	Protocol *config.Protocol

	// HTTPClientContext tracks the context for an HTTP client connection.
	HTTPClientContext *gin.Context

	// MonitoringFlags is a slice of global.Monitoring that is used to skip certain steps while processing an authentication request.
	MonitoringFlags []global.Monitoring

	// MasterUserMode is a flag for a backend to indicate a master user mode is ongoing.
	MasterUserMode bool

	*backend.PasswordHistory
	*lualib.Context
}

// PassDBResult is used in all password databases to store final results of an authentication process.
type PassDBResult struct {
	// Authenticated is a flag that is set if a user was not only found, but also succeeded authentication.
	Authenticated bool

	// UserFound is a flag that is set if the user was found in a password Database.
	UserFound bool

	// AccountField is the SQL field or LDAP attribute that was used for the user account.
	AccountField *string

	// TOTPSecretField is set by the Database which has found the user.
	TOTPSecretField *string

	// TOTPRecoveryField NYI
	TOTPRecoveryField *string

	// UniqueUserIDField is a string representing a unique user identifier.
	UniqueUserIDField *string

	// DisplayNameField is the display name of a user
	DisplayNameField *string

	// Backend is set by the Database backend which has found the user.
	Backend global.Backend

	// Attributes is the result catalog returned by the underlying password Database.
	Attributes backend.DatabaseResult
}

type (
	// PassDBOption
	// This type specifies the signature of a password database.
	PassDBOption func(auth *Authentication) (*PassDBResult, error)

	// PassDBMap is a struct type that represents a mapping between a backend type and a PassDBOption function.
	// It is used in the verifyPassword method of the Authentication struct to perform password verification against multiple databases.
	// The backend field represents the type of database backend (global.Backend) and the fn field represents the PassDBOption function.
	// The PassDBOption function takes an Authentication pointer as input and returns a PassDBResult pointer and an error.
	// The PassDBResult pointer contains the result of the password verification process.
	// This struct is used to store the database mappings in an array and loop through them in the verifyPassword method.
	PassDBMap struct {
		backend global.Backend
		fn      PassDBOption
	}
)

type (
	// AccountList is a slice of strings containing the list of all user accounts.
	AccountList []string

	// AccountListOption is the function signature for an account Database.
	AccountListOption func(a *Authentication) (AccountList, error)

	// AccountListMap is a struct type that represents a mapping between a backend and an account list option function for authentication.
	AccountListMap struct {
		backend global.Backend
		fn      AccountListOption
	}
)

// WebAuthnCredentialDBFunc defines a signature for WebAuthn credential object lookups
type WebAuthnCredentialDBFunc func(uniqueUserID string) ([]webauthn.Credential, error)

// AddTOTPSecretFunc is a function signature that takes a *Authentication and *TOTPSecret as arguments and returns an error.
type AddTOTPSecretFunc func(auth *Authentication, totp *TOTPSecret) (err error)

var BackendServers = NewBackendServer()

// String returns an Authentication object as string excluding the user password.
func (a *Authentication) String() string {
	var result string

	value := reflect.ValueOf(a)
	typeOfValue := value.Type()

	for index := range value.NumField() {
		switch typeOfValue.Field(index).Name {
		case "GUID":
			continue
		case "Password":
			if config.EnvConfig.DevMode {
				result += fmt.Sprintf(" %s='%v'", typeOfValue.Field(index).Name, value.Field(index).Interface())
			} else {
				result += fmt.Sprintf(" %s='<hidden>'", typeOfValue.Field(index).Name)
			}
		default:
			result += fmt.Sprintf(" %s='%v'", typeOfValue.Field(index).Name, value.Field(index).Interface())
		}
	}

	return result[1:]
}

// LogLineMail returns an array of key-value pairs used for logging mail information.
// The array includes the following information:
// - session: the session GUID
// - protocol: the protocol used
// - local_ip: the local IP address
// - port: the port number
// - client_ip: the client IP address
// - client_port: the client port number
// - client_host: the client host
// - tls_protocol: the TLS protocol used
// - tls_cipher: the TLS cipher used
// - auth_method: the authentication method
// - username: the username
// - orig_username: the original username
// - passdb_backend: the used password database backend
// - current_password_retries: the number of current password retries
// - account_passwords_seen: the number of account passwords seen
// - total_passwords_seen: the total number of passwords seen
// - user_agent: the user agent
// - client_id: the client ID
// - brute_force_bucket: the brute force bucket name
// - feature: the feature name
// - status_message: the status message
// - uri_path: the URI path
// - authenticated: the authentication status
func (a *Authentication) LogLineMail(status string, endpoint string) []any {
	var keyvals []any

	keyvals = []any{
		global.LogKeyGUID, util.WithNotAvailable(*a.GUID),
		global.LogKeyProtocol, util.WithNotAvailable(a.Protocol.String()),
		global.LogKeyLocalIP, util.WithNotAvailable(a.XLocalIP),
		global.LogKeyPort, util.WithNotAvailable(a.XPort),
		global.LogKeyClientIP, util.WithNotAvailable(a.ClientIP),
		global.LogKeyClientPort, util.WithNotAvailable(a.XClientPort),
		global.LogKeyClientHost, util.WithNotAvailable(a.ClientHost),
		global.LogKeyTLSSecure, util.WithNotAvailable(a.XSSLProtocol),
		global.LogKeyTLSCipher, util.WithNotAvailable(a.XSSLCipher),
		global.LogKeyAuthMethod, util.WithNotAvailable(a.Method),
		global.LogKeyUsername, util.WithNotAvailable(a.Username),
		global.LogKeyOrigUsername, util.WithNotAvailable(a.UsernameOrig),
		global.LogKeyUsedPassdbBackend, util.WithNotAvailable(a.UsedPassDBBackend.String()),
		global.LogKeyLoginAttempts, a.LoginAttempts,
		global.LogKeyPasswordsAccountSeen, a.PasswordsAccountSeen,
		global.LogKeyPasswordsTotalSeen, a.PasswordsTotalSeen,
		global.LogKeyUserAgent, util.WithNotAvailable(a.UserAgent),
		global.LogKeyClientID, util.WithNotAvailable(a.XClientID),
		global.LogKeyBruteForceName, util.WithNotAvailable(a.BruteForceName),
		global.LogKeyFeatureName, util.WithNotAvailable(a.FeatureName),
		global.LogKeyStatusMessage, util.WithNotAvailable(a.StatusMessage),
		global.LogKeyUriPath, endpoint,
		global.LogKeyStatus, util.WithNotAvailable(status),
	}

	if len(a.AdditionalLogs) > 0 {
		if len(a.AdditionalLogs)%2 == 0 {
			for index := range a.AdditionalLogs {
				keyvals = append(keyvals, a.AdditionalLogs[index])
			}
		}
	}

	return keyvals
}

// getAccount returns the account value from the Authentication object. If the account field is not set or the account
// value is not found in the attributes, an empty string is returned
func (a *Authentication) getAccount() string {
	if a.AccountField == nil {
		return ""
	}

	if account, okay := a.Attributes[*a.AccountField]; okay {
		if value, assertOk := account[global.LDAPSingleValue].(string); assertOk {
			return value
		}
	}

	return ""
}

// getAccountOk returns the account name of a user. If there is no account, it returns the empty string "". A boolean
// is set to return a "found" flag.
func (a *Authentication) getAccountOk() (string, bool) {
	account := a.getAccount()

	return account, account != ""
}

// getTOTPSecret returns the TOTP secret for a user. If there is no secret, it returns the empty string "".
func (a *Authentication) getTOTPSecret() string {
	if a.TOTPSecretField == nil {
		return ""
	}

	if totpSecret, okay := a.Attributes[*a.TOTPSecretField]; okay {
		if value, assertOk := totpSecret[global.LDAPSingleValue].(string); assertOk {
			return value
		}
	}

	return ""
}

// getTOTPSecretOk returns the TOTP secret for a user. If there is no secret, it returns the empty string "". A boolean
// is set to return a "found" flag.
func (a *Authentication) getTOTPSecretOk() (string, bool) {
	totpSecret := a.getTOTPSecret()

	return totpSecret, totpSecret != ""
}

// getUniqueUserID returns the unique WebAuthn user identifier for a user. If there is no id, it returns the empty string "".
func (a *Authentication) getUniqueUserID() string {
	if a.UniqueUserIDField == nil {
		return ""
	}

	if webAuthnUserID, okay := a.Attributes[*a.UniqueUserIDField]; okay {
		if value, assertOk := webAuthnUserID[global.LDAPSingleValue].(string); assertOk {
			return value
		}
	}

	return ""
}

// GetUniqueUserIDOk returns the unique identifier for a user. If there is no id, it returns the empty string "". A boolean
// is set to return a "found" flag.
func (a *Authentication) GetUniqueUserIDOk() (string, bool) {
	uniqueUserID := a.getUniqueUserID()

	return uniqueUserID, uniqueUserID != ""
}

// getDisplayName returns the display name for a user. If there is no account, it returns the empty string "".
func (a *Authentication) getDisplayName() string {
	if a.DisplayNameField == nil {
		return ""
	}

	if account, okay := a.Attributes[*a.DisplayNameField]; okay {
		if value, assertOk := account[global.SliceWithOneElement].(string); assertOk {
			return value
		}
	}

	return ""
}

// GetDisplayNameOk returns the display name of a user. If there is no account, it returns the empty string "". A boolean
// is set to return a "found" flag.
func (a *Authentication) GetDisplayNameOk() (string, bool) {
	displayName := a.getDisplayName()

	return displayName, displayName != ""
}

// authOK is the general method to indicate authentication success.
func (a *Authentication) authOK(ctx *gin.Context) {
	setCommonHeaders(ctx, a)
	switch a.Service {
	case global.ServNginx:
		setNginxHeaders(ctx, a)
	case global.ServDovecot:
		setDovecotHeaders(ctx, a)
	case global.ServUserInfo, global.ServJSON:
		setUserInfoHeaders(ctx, a)
	}

	cachedAuth := ctx.GetBool(global.CtxLocalCacheAuthKey)

	if cachedAuth {
		ctx.Header("X-Auth-Cache", "Hit")
	} else {
		ctx.Header("X-Auth-Cache", "Miss")
	}

	handleLogging(ctx, a)

	stats.LoginsCounter.WithLabelValues(global.LabelSuccess).Inc()
}

// setCommonHeaders sets common headers for the given gin.Context and Authentication.
// It sets the "Auth-Status" header to "OK" and the "X-Nauthilus-Session" header to the GUID of the Authentication.
// If the Authentication's Service is not global.ServBasicAuth and the UsernameReplace flag is true, it retrieves the account from the Authentication and sets the "Auth-User" header
func setCommonHeaders(ctx *gin.Context, a *Authentication) {
	ctx.Header("Auth-Status", "OK")
	ctx.Header("X-Nauthilus-Session", *a.GUID)

	if a.Service != global.ServBasicAuth && a.UsernameReplace {
		if account, found := a.getAccountOk(); found {
			ctx.Header("Auth-User", account)
		}
	}
}

// setNginxHeaders sets the appropriate headers for the given gin.Context and Authentication based on the configuration and feature flags.
// If the global.FeatureBackendServersMonitoring feature is enabled, it checks if the Authentication's UsedBackendAddress and UsedBackendPort are set.
// If they are, it sets the "Auth-Server" header to the UsedBackendAddress and the "Auth-Port" header to the UsedBackendPort.
// If the global.FeatureBackendServersMonitoring feature is disabled, it checks the Authentication's Protocol.
// If the Protocol is global.ProtoSMTP, it sets the "Auth-Server" header to the SMTPBackendAddress and the "Auth-Port" header to the SMTPBackendPort.
// If the Protocol is global.ProtoIMAP, it sets the "Auth-Server" header to the IMAPBackendAddress and the "Auth-Port" header to the IMAPBackendPort.
// If the Protocol is global.ProtoPOP3, it sets the "Auth-Server" header to the POP3BackendAddress and the "Auth-Port" header to the POP3BackendPort.
func setNginxHeaders(ctx *gin.Context, a *Authentication) {
	if config.LoadableConfig.HasFeature(global.FeatureBackendServersMonitoring) {
		if BackendServers.GetTotalServers() == 0 {
			ctx.Header("Auth-Status", "Internal failure")
		} else {
			if a.UsedBackendIP != "" && a.UsedBackendPort > 0 {
				ctx.Header("Auth-Server", a.UsedBackendIP)
				ctx.Header("Auth-Port", fmt.Sprintf("%d", a.UsedBackendPort))
			}
		}
	} else {
		switch a.Protocol.Get() {
		case global.ProtoSMTP:
			ctx.Header("Auth-Server", config.EnvConfig.SMTPBackendAddress)
			ctx.Header("Auth-Port", fmt.Sprintf("%d", config.EnvConfig.SMTPBackendPort))
		case global.ProtoIMAP:
			ctx.Header("Auth-Server", config.EnvConfig.IMAPBackendAddress)
			ctx.Header("Auth-Port", fmt.Sprintf("%d", config.EnvConfig.IMAPBackendPort))
		case global.ProtoPOP3:
			ctx.Header("Auth-Server", config.EnvConfig.POP3BackendAddress)
			ctx.Header("Auth-Port", fmt.Sprintf("%d", config.EnvConfig.POP3BackendPort))
		}
	}
}

// setDovecotHeaders sets the specified headers in the given gin.Context based on the attributes in the Authentication object.
// It iterates through the attributes and calls the handleAttributeValue function for each attribute.
//
// Parameters:
// - ctx: The gin.Context object to set the headers on.
// - a: The Authentication object containing the attributes.
//
// Example:
//
//	a := &Authentication{
//	    Attributes: map[string][]any{
//	        "Attribute1": []any{"Value1"},
//	        "Attribute2": []any{"Value2_1", "Value2_2"},
//	    },
//	}
//	setDovecotHeaders(ctx, a)
//
// Resulting headers in ctx:
// - X-Nauthilus-Attribute1: "Value1"
// - X-Nauthilus-Attribute2: "Value2_1,Value2_2"
func setDovecotHeaders(ctx *gin.Context, a *Authentication) {
	if a.Attributes != nil && len(a.Attributes) > 0 {
		for name, value := range a.Attributes {
			handleAttributeValue(ctx, name, value)
		}
	}
}

// handleAttributeValue sets the value of a header in the given gin.Context based on the name and value provided.
// If the value length is 1, it formats the value as a string and assigns it to the headerValue variable.
// If the value length is greater than 1, it formats each value and joins them with a comma separator, unless the name is "dn",
// in which case it joins them with a semicolon separator.
// Finally, it adds the header "X-Nauthilus-" + name with the value of headerValue to the gin.Context.
// Parameters:
// - ctx: the gin.Context to set the header in
// - name: the name of the header
// - value: the value of the header
func handleAttributeValue(ctx *gin.Context, name string, value []any) {
	var headerValue string

	if valueLen := len(value); valueLen > 0 {
		switch {
		case valueLen == 1:
			headerValue = fmt.Sprintf("%v", value[global.LDAPSingleValue])
		default:
			stringValues := formatValues(value)
			separator := ","

			if name == global.DistinguishedName {
				separator = ";"
			}

			headerValue = strings.Join(stringValues, separator)
		}

		ctx.Header("X-Nauthilus-"+name, fmt.Sprintf("%v", headerValue))
	}
}

// formatValues takes an array of values and formats them into strings.
// It creates an empty slice of strings called stringValues.
// It then iterates over each value in the values array and appends the formatted string representation of that value to stringValues using fmt.Sprintf("%v", values[index]).
// After iterating over all the values, it returns stringValues.
// Example usage:
// values := []any{"one", "two", "three"}
// result := formatValues(values)
// fmt.Println(result) // Output: ["one", "two", "three"]
func formatValues(values []any) []string {
	var stringValues []string

	for index := range values {
		stringValues = append(stringValues, fmt.Sprintf("%v", values[index]))
	}

	return stringValues
}

// setUserInfoHeaders sets the necessary headers for the user info response.
// It includes the Content-Type header with the value "application/json; charset=UTF-8".
// It also includes the X-User-Found header with the string representation of a.UserFound.
// Finally, it uses ctx.JSON to send a JSON response with a status code of a.StatusCodeOK and a body of backend.PositivePasswordCache.
func setUserInfoHeaders(ctx *gin.Context, a *Authentication) {
	ctx.Header("Content-Type", "application/json; charset=UTF-8")
	ctx.Header("X-User-Found", fmt.Sprintf("%v", a.UserFound))
	ctx.JSON(a.StatusCodeOK, &backend.PositivePasswordCache{
		AccountField:    a.AccountField,
		TOTPSecretField: a.TOTPSecretField,
		Backend:         a.SourcePassDBBackend,
		Attributes:      a.Attributes,
	})
}

// handleLogging logs information about the authentication request if the verbosity level is greater than LogLevelWarn.
// It uses the logging.DefaultLogger to log the information.
// The logged information includes the result of the a.LogLineMail() function, which returns either "ok" or an empty string depending on the value of a.NoAuth,
// and the path of the request URL obtained from ctx.Request.URL.Path.
func handleLogging(ctx *gin.Context, a *Authentication) {
	level.Info(logging.DefaultLogger).Log(a.LogLineMail(func() string {
		if !a.NoAuth {
			return "ok"
		}

		return ""
	}(), ctx.Request.URL.Path)...)
}

// increaseLoginAttempts increments the number of login attempts for the Authentication object.
// If the number of login attempts exceeds the maximum value allowed (MaxUint8), it sets it to the maximum value.
// If the Authentication service is equal to ServNginx and the number of login attempts is less than the maximum login attempts specified in the environment configuration,
// it increments the number of login attempts by one.
// The usage example of this method can be found in the authFail function.
func (a *Authentication) increaseLoginAttempts() {
	if a.LoginAttempts > math.MaxUint8 {
		a.LoginAttempts = math.MaxUint8
	}

	if a.Service == global.ServNginx {
		if a.LoginAttempts < uint(config.EnvConfig.MaxLoginAttempts) {
			a.LoginAttempts++
		}
	}
}

// setFailureHeaders sets the failure headers for the given authentication context.
// It sets the "Auth-Status" header to the value of global.PasswordFail constant.
// It sets the "X-Nauthilus-Session" header to the value of the authentication's GUID field.
// It updates the StatusMessage of the authentication to global.PasswordFail.
//
// If the Service field of the authentication is equal to global.ServUserInfo, it also sets the following headers:
//   - "Content-Type" header to "application/json; charset=UTF-8"
//   - "X-User-Found" header to the string representation of the UserFound field of the authentication
//   - If the PasswordHistory field is not nil, it responds with a JSON representation of the PasswordHistory.
//     If the PasswordHistory field is nil, it responds with an empty JSON object.
//
// If the Service field is not equal to global.ServUserInfo, it responds with the StatusMessage of the authentication as plain text.
func (a *Authentication) setFailureHeaders(ctx *gin.Context) {
	if a.StatusMessage == "" {
		a.StatusMessage = global.PasswordFail
	}

	ctx.Header("Auth-Status", a.StatusMessage)
	ctx.Header("X-Nauthilus-Session", *a.GUID)

	if a.Service == global.ServUserInfo {
		ctx.Header("Content-Type", "application/json; charset=UTF-8")
		ctx.Header("X-User-Found", fmt.Sprintf("%v", a.UserFound))

		if a.PasswordHistory != nil {
			ctx.JSON(a.StatusCodeFail, *a.PasswordHistory)
		} else {
			ctx.JSON(a.StatusCodeFail, struct{}{})
		}
	} else {
		ctx.String(a.StatusCodeFail, a.StatusMessage)
	}
}

// loginAttemptProcessing performs processing for a failed login attempt.
// It checks the verbosity level in the environment configuration and logs the failed login attempt if it is greater than LogLevelWarn.
// It then increments the LoginsCounter with the LabelFailure.
//
// Example usage:
//
//	a := &Authentication{}
//	ctx := &gin.Context{}
//	a.loginAttemptProcessing(ctx)
func (a *Authentication) loginAttemptProcessing(ctx *gin.Context) {
	level.Info(logging.DefaultLogger).Log(a.LogLineMail("fail", ctx.Request.URL.Path)...)

	stats.LoginsCounter.WithLabelValues(global.LabelFailure).Inc()
}

// authFail handles the failure of authentication.
// It increases the login attempts, sets failure headers on the context, and performs login attempt processing.
func (a *Authentication) authFail(ctx *gin.Context) {
	a.increaseLoginAttempts()
	a.setFailureHeaders(ctx)
	a.loginAttemptProcessing(ctx)
}

// setSMPTHeaders sets SMTP headers in the specified `gin.Context` if the `Service` is `ServNginx` and the `Protocol` is `ProtoSMTP`.
// It adds the `Auth-Error-Code` header with the value `TempFailCode` from the declaration package.
//
// Example usage:
//
//	a.setSMPTHeaders(ctx)
func (a *Authentication) setSMPTHeaders(ctx *gin.Context) {
	if a.Service == global.ServNginx && a.Protocol.Get() == global.ProtoSMTP {
		ctx.Header("Auth-Error-Code", global.TempFailCode)
	}
}

// setUserInfoHeaders sets the necessary headers for UserInfo service in a Gin context
// Usage example:
//
//	func (a *Authentication) authTempFail(ctx *gin.Context, reason string) {
//	    ...
//	    if a.Service == global.ServUserInfo {
//	        a.setUserInfoHeaders(ctx, reason)
//	        return
//	    }
//	    ...
//	}
//
// params:
// - ctx: Gin context
// - reason: Error reason to include in the response
func (a *Authentication) setUserInfoHeaders(ctx *gin.Context, reason string) {
	type errType struct {
		Error string
	}

	ctx.Header("Content-Type", "application/json; charset=UTF-8")
	ctx.Header("X-User-Found", fmt.Sprintf("%v", a.UserFound))

	ctx.JSON(a.StatusCodeInternalError, &errType{Error: reason})
}

// authTempFail sets the necessary headers and status message for temporary authentication failure.
// If the service is "user", it also sets headers specific to user information.
// After setting the headers, it returns the appropriate response based on the service.
// If the service is not "user", it returns an internal server error response with the status message.
// If the service is "user", it calls the setUserInfoHeaders method to set additional headers and returns.
//
// Parameters:
// - ctx: The gin context object.
// - reason: The reason for the authentication failure.
//
// Usage example:
//
//	  func (a *Authentication) generic(ctx *gin.Context) {
//	    ...
//	    a.authTempFail(ctx, global.TempFailDefault)
//	    ...
//	  }
//	  func (a *Authentication) saslAuthd(ctx *gin.Context) {
//		   ...
//	    a.authTempFail(ctx, global.TempFailDefault)
//	    ...
//	  }
//
// Declaration and usage of authTempFail:
//
//	A: func (a *Authentication) authTempFail(ctx *gin.Context, reason string) {
//	  ...
//	}
func (a *Authentication) authTempFail(ctx *gin.Context, reason string) {
	ctx.Header("Auth-Status", reason)
	ctx.Header("X-Nauthilus-Session", *a.GUID)
	a.setSMPTHeaders(ctx)

	a.StatusMessage = reason

	if a.Service == global.ServUserInfo {
		a.setUserInfoHeaders(ctx, reason)
		return
	}

	ctx.String(a.StatusCodeInternalError, a.StatusMessage)
	level.Info(logging.DefaultLogger).Log(a.LogLineMail("tempfail", ctx.Request.URL.Path)...)
}

// isMasterUser checks whether the current user is a master user based on the MasterUser configuration in the LoadableConfig.
// It returns true if MasterUser is enabled and the number of occurrences of the delimiter in the Username is equal to 1, otherwise it returns false.
func (a *Authentication) isMasterUser() bool {
	if config.LoadableConfig.Server.MasterUser.Enabled {
		if strings.Count(a.Username, config.LoadableConfig.Server.MasterUser.Delimiter) == 1 {
			parts := strings.Split(a.Username, config.LoadableConfig.Server.MasterUser.Delimiter)
			if len(parts[0]) > 0 && len(parts[1]) > 0 {
				return true
			}
		}
	}

	return false
}

// isInNetwork checks an IP address against a network and returns true if it matches.
func (a *Authentication) isInNetwork(networkList []string) (matchIP bool) {
	ipAddress := net.ParseIP(a.ClientIP)

	for _, ipOrNet := range networkList {
		if net.ParseIP(ipOrNet) == nil {
			_, network, err := net.ParseCIDR(ipOrNet)
			if err != nil {
				a.logNetworkError(ipOrNet, err)

				continue
			}

			a.checkAndLogNetwork(network)

			if network.Contains(ipAddress) {
				matchIP = true

				break
			}
		} else {
			a.checkAndLogIP(ipOrNet)
			if a.ClientIP == ipOrNet {
				matchIP = true

				break
			}
		}
	}

	return
}

// logNetworkError logs a network error message.
//
// Parameters:
// - ipOrNet (string): The IP or network causing the error.
// - err (error): The error information.
//
// Usage example:
// a.logNetworkError(ipOrNet, err)
func (a *Authentication) logNetworkError(ipOrNet string, err error) {
	level.Error(logging.DefaultErrLogger).Log(global.LogKeyGUID, a.GUID, global.LogKeyMsg, "%s is not a network", ipOrNet, global.LogKeyError, err)
}

// checkAndLogNetwork logs the information about checking a network for the given authentication object.
func (a *Authentication) checkAndLogNetwork(network *net.IPNet) {
	util.DebugModule(
		global.DbgWhitelist,
		global.LogKeyGUID, a.GUID, global.LogKeyMsg, fmt.Sprintf("Checking: %s -> %s", a.ClientIP, network.String()),
	)
}

// checkAndLogIP logs the IP address of the client along with the IP address or network being checked.
func (a *Authentication) checkAndLogIP(ipOrNet string) {
	util.DebugModule(global.DbgWhitelist, global.LogKeyGUID, a.GUID, global.LogKeyMsg, fmt.Sprintf("Checking: %s -> %s", a.ClientIP, ipOrNet))
}

// verifyPassword takes in an array of PassDBMap and performs the following steps:
// - Check if there are any password databases available
// - Iterate over each password database and call the corresponding function
// - Log debug information for each database and its result
// - Handle any backend errors and store them in a map
// - If there is no error, authenticate the user using the result returned by the database function
// - If authentication is successful or NoAuth flag is set, return the passDBResult and nil error
//
// Parameters:
// - passDBs: an array of PassDBMap which contains the backend type and the corresponding function to be called
//
// Return values:
// - passDBResult: a pointer to a PassDBResult struct which contains the authentication result
// - err: an error that occurred during the verification process
func (a *Authentication) verifyPassword(passDBs []*PassDBMap) (*PassDBResult, error) {
	var (
		passDBResult *PassDBResult
		err          error
	)

	configErrors := make(map[global.Backend]error, len(passDBs))
	for passDBIndex, passDB := range passDBs {
		passDBResult, err = passDB.fn(a)
		logDebugModule(a, passDB, passDBResult)

		if err != nil {
			err = handleBackendErrors(passDBIndex, passDBs, passDB, err, a, configErrors)
			if err != nil {
				break
			}
		} else {
			passDBResult, err = authenticateUser(passDBResult, a, passDB)
			if err != nil || a.UserFound {
				break
			}
		}
	}

	// Enforce authentication
	if a.NoAuth {
		passDBResult.Authenticated = true
	}

	return passDBResult, err
}

// logDebugModule logs debug information about the authentication process.
//
// Parameters:
//   - a: The Authentication object associated with the authentication process.
//   - passDB: The PassDBMap object representing the password database.
//   - passDBResult: The PassDBResult object containing the result of the authentication process.
//
// The logDebugModule function calls the util.DebugModule function to log the debug information.
// It passes the module declaration (global.DbgAuth) as the first parameter, followed by key-value pairs of additional information.
// The key-value pairs include "session" as the key and a.GUID as the value, "passdb" as the key and passDB.backend.String() as the value,
// and "result" as the key and fmt.Sprintf("%v", passDBResult) as the value.
//
// Example Usage:
//
//	logDebugModule(a, passDB, passDBResult)
//
// This function uses the util.DebugModule function from the package to log the debug information.
func logDebugModule(a *Authentication, passDB *PassDBMap, passDBResult *PassDBResult) {
	util.DebugModule(
		global.DbgAuth,
		global.LogKeyGUID, a.GUID,
		"passdb", passDB.backend.String(),
		"result", fmt.Sprintf("%v", passDBResult))
}

// handleBackendErrors handles the errors that occur during backend processing.
// It checks if the error is a configuration error for SQL, LDAP, or Lua backends and adds them to the configErrors map.
// If all password databases have been processed and there are configuration errors, it calls the checkAllBackends function.
// If the error is not a configuration error, it logs the error using the DefaultErrLogger.
// It returns the error unchanged.
func handleBackendErrors(passDBIndex int, passDBs []*PassDBMap, passDB *PassDBMap, err error, a *Authentication, configErrors map[global.Backend]error) error {
	if errors.Is(err, errors2.ErrLDAPConfig) || errors.Is(err, errors2.ErrLuaConfig) {
		configErrors[passDB.backend] = err

		// After all password databases were running,  check if SQL, LDAP and Lua  backends have configuration errors.
		if passDBIndex == len(passDBs)-1 {
			err = checkAllBackends(configErrors, a)
		}
	} else {
		level.Error(logging.DefaultErrLogger).Log(global.LogKeyGUID, a.GUID, "passdb", passDB.backend.String(), global.LogKeyError, err)
	}

	return err
}

// After all password databases were running, check if SQL, LDAP and Lua backends have configuration errors.
func checkAllBackends(configErrors map[global.Backend]error, a *Authentication) (err error) {
	var allConfigErrors = true

	for _, err = range configErrors {
		if err == nil {
			allConfigErrors = false

			break
		}
	}

	// If all (real) Database backends failed, we must return with a temporary failure
	if allConfigErrors {
		err = errors2.ErrAllBackendConfigError
		level.Error(logging.DefaultErrLogger).Log(global.LogKeyGUID, a.GUID, "passdb", "all", global.LogKeyError, err)
	}

	return err
}

// authenticateUser updates the passDBResult based on the provided passDB
// and the Authentication object a.
// If passDBResult is nil, it returns an error of type errors2.ErrNoPassDBResult.
// It then calls the util.DebugModule function to log debug information.
// Next, it calls the updateAuthentication function to update the fields of a based on the values in passDBResult.
// If the UserFound field of passDBResult is true, it sets the UserFound field of a to true.
// Finally, it returns the updated passDBResult and nil error.
func authenticateUser(passDBResult *PassDBResult, a *Authentication, passDB *PassDBMap) (*PassDBResult, error) {
	if passDBResult == nil {
		return passDBResult, errors2.ErrNoPassDBResult
	}

	util.DebugModule(
		global.DbgAuth,
		global.LogKeyGUID, a.GUID,
		"passdb", passDB.backend.String(),
		global.LogKeyUsername, a.Username,
		global.LogKeyOrigUsername, a.UsernameOrig,
		"passdb_result", fmt.Sprintf("%+v", *passDBResult),
	)

	passDBResult = updateAuthentication(a, passDBResult, passDB)

	if passDBResult.UserFound {
		a.UserFound = true
	}

	return passDBResult, nil
}

// updateAuthentication updates the fields of the Authentication struct with the values from the PassDBResult struct.
// It checks if each field in passDBResult is not nil and if it is not nil, it updates the corresponding field in the Authentication struct.
// It also updates the SourcePassDBBackend and UsedPassDBBackend fields of the Authentication struct with the values from passDBResult.Backend and passDB.backend respectively.
// It returns the updated PassDBResult struct.
func updateAuthentication(a *Authentication, passDBResult *PassDBResult, passDB *PassDBMap) *PassDBResult {
	if passDBResult.AccountField != nil {
		a.AccountField = passDBResult.AccountField
	}

	if passDBResult.TOTPSecretField != nil {
		a.TOTPSecretField = passDBResult.TOTPSecretField
	}

	if passDBResult.UniqueUserIDField != nil {
		a.UniqueUserIDField = passDBResult.UniqueUserIDField
	}

	if passDBResult.DisplayNameField != nil {
		a.DisplayNameField = passDBResult.DisplayNameField
	}

	if passDBResult.Attributes != nil && len(passDBResult.Attributes) > 0 {
		a.Attributes = passDBResult.Attributes
	}

	a.SourcePassDBBackend = passDBResult.Backend
	a.UsedPassDBBackend = passDB.backend

	return passDBResult
}

// setStatusCodes sets different status codes for various services.
func (a *Authentication) setStatusCodes(service string) error {
	switch service {
	case global.ServNginx, global.ServDovecot:
		a.StatusCodeOK = http.StatusOK
		a.StatusCodeInternalError = http.StatusOK
		a.StatusCodeFail = http.StatusOK
	case global.ServSaslauthd, global.ServBasicAuth, global.ServOryHydra, global.ServUserInfo, global.ServJSON:
		a.StatusCodeOK = http.StatusOK
		a.StatusCodeInternalError = http.StatusInternalServerError
		a.StatusCodeFail = http.StatusForbidden
	default:
		return errors2.ErrUnknownService
	}

	return nil
}

// handleFeatures iterates through the list of enabled features and returns true, if a feature returned positive.
func (a *Authentication) handleFeatures(ctx *gin.Context) (authResult global.AuthResult) {
	// Helper function that sends an action request and waits for it to be finished. Features may change the Lua context.
	// Lua post actions may make use of these changes.
	doAction := func(luaAction global.LuaAction, luaActionName string) {
		if !config.LoadableConfig.HaveLuaActions() {
			return
		}

		timer := prometheus.NewTimer(stats.FunctionDuration.WithLabelValues("Action", luaActionName))

		defer timer.ObserveDuration()

		finished := make(chan action.Done)

		action.RequestChan <- &action.Action{
			LuaAction:    luaAction,
			Context:      a.Context,
			FinishedChan: finished,
			HTTPRequest:  a.HTTPClientContext.Request,
			CommonRequest: &lualib.CommonRequest{
				Debug:               config.LoadableConfig.Server.Log.Level.Level() == global.LogLevelDebug,
				Repeating:           false,
				UserFound:           false, // unavailable
				Authenticated:       false, // unavailable
				NoAuth:              a.NoAuth,
				BruteForceCounter:   0, // unavailable
				Service:             a.Service,
				Session:             *a.GUID,
				ClientIP:            a.ClientIP,
				ClientPort:          a.XClientPort,
				ClientNet:           "", // unavailable
				ClientHost:          a.ClientHost,
				ClientID:            a.XClientID,
				LocalIP:             a.XLocalIP,
				LocalPort:           a.XPort,
				UserAgent:           *a.UserAgent,
				Username:            a.UsernameOrig,
				Account:             "", // unavailable
				UniqueUserID:        "", // unavailable
				DisplayName:         "", // unavailable
				Password:            a.Password,
				Protocol:            a.Protocol.Get(),
				BruteForceName:      "", // unavailable
				FeatureName:         a.FeatureName,
				StatusMessage:       &a.StatusMessage,
				XSSL:                a.XSSL,
				XSSLSessionID:       a.XSSLSessionID,
				XSSLClientVerify:    a.XSSLClientVerify,
				XSSLClientDN:        a.XSSLClientDN,
				XSSLClientCN:        a.XSSLClientCN,
				XSSLIssuer:          a.XSSLIssuer,
				XSSLClientNotBefore: a.XSSLClientNotBefore,
				XSSLClientNotAfter:  a.XSSLClientNotAfter,
				XSSLSubjectDN:       a.XSSLSubjectDN,
				XSSLIssuerDN:        a.XSSLIssuerDN,
				XSSLClientSubjectDN: a.XSSLClientSubjectDN,
				XSSLClientIssuerDN:  a.XSSLClientIssuerDN,
				XSSLProtocol:        a.XSSLProtocol,
				XSSLCipher:          a.XSSLCipher,
			},
		}

		<-finished
	}

	/*
	 * Black or whitelist features
	 */

	if config.LoadableConfig.HasFeature(global.FeatureLua) {
		if config.LoadableConfig.HaveLuaFeatures() {
			if triggered, abortFeatures, err := a.featureLua(ctx); err != nil {
				return global.AuthResultTempFail
			} else if triggered {
				a.FeatureName = global.FeatureLua

				a.updateBruteForceBucketsCounter()
				doAction(global.LuaActionLua, global.LuaActionLuaName)

				return global.AuthResultFeatureLua
			} else if abortFeatures {
				return global.AuthResultOK
			}
		}
	}

	/*
	 * Blacklist features
	 */

	if config.LoadableConfig.HasFeature(global.FeatureTLSEncryption) {
		if a.featureTLSEncryption() {
			a.FeatureName = global.FeatureTLSEncryption

			doAction(global.LuaActionTLS, global.LuaActionTLSName)

			return global.AuthResultFeatureTLS
		}
	}

	if config.LoadableConfig.HasFeature(global.FeatureRelayDomains) {
		if a.featureRelayDomains() {
			a.FeatureName = global.FeatureRelayDomains

			a.updateBruteForceBucketsCounter()
			doAction(global.LuaActionRelayDomains, global.LuaActionRelayDomainsName)

			return global.AuthResultFeatureRelayDomain
		}
	}

	if config.LoadableConfig.HasFeature(global.FeatureRBL) {
		if triggered, err := a.featureRBLs(ctx); err != nil {
			return global.AuthResultTempFail
		} else if triggered {
			a.FeatureName = global.FeatureRBL

			a.updateBruteForceBucketsCounter()
			doAction(global.LuaActionRBL, global.LuaActionRBLName)

			return global.AuthResultFeatureRBL
		}
	}

	return global.AuthResultOK
}

// postLuaAction sends a Lua action to be executed asynchronously.
func (a *Authentication) postLuaAction(passDBResult *PassDBResult) {
	if !config.LoadableConfig.HaveLuaActions() {
		return
	}

	go func() {
		timer := prometheus.NewTimer(stats.FunctionDuration.WithLabelValues("PostAction", "postLuaAction"))

		defer timer.ObserveDuration()

		finished := make(chan action.Done)

		action.RequestChan <- &action.Action{
			LuaAction:    global.LuaActionPost,
			Context:      a.Context,
			FinishedChan: finished,
			HTTPRequest:  a.HTTPClientContext.Request,
			CommonRequest: &lualib.CommonRequest{
				Debug:             config.LoadableConfig.Server.Log.Level.Level() == global.LogLevelDebug,
				Repeating:         false,
				UserFound:         passDBResult.UserFound,
				Authenticated:     passDBResult.Authenticated,
				NoAuth:            a.NoAuth,
				BruteForceCounter: 0,
				Service:           a.Service,
				Session:           *a.GUID,
				ClientIP:          a.ClientIP,
				ClientPort:        a.XClientPort,
				ClientNet:         "", // unavailable
				ClientHost:        a.ClientHost,
				ClientID:          a.XClientID,
				LocalIP:           a.XLocalIP,
				LocalPort:         a.XPort,
				UserAgent:         *a.UserAgent,
				Username:          a.Username,
				Account: func() string {
					if passDBResult.UserFound {
						return a.getAccount()
					}

					return ""
				}(),
				UniqueUserID:        a.getUniqueUserID(),
				DisplayName:         a.getDisplayName(),
				Password:            a.Password,
				Protocol:            a.Protocol.Get(),
				BruteForceName:      a.BruteForceName,
				FeatureName:         a.FeatureName,
				StatusMessage:       &a.StatusMessage,
				XSSL:                a.XSSL,
				XSSLSessionID:       a.XSSLSessionID,
				XSSLClientVerify:    a.XSSLClientVerify,
				XSSLClientDN:        a.XSSLClientDN,
				XSSLClientCN:        a.XSSLClientCN,
				XSSLIssuer:          a.XSSLIssuer,
				XSSLClientNotBefore: a.XSSLClientNotBefore,
				XSSLClientNotAfter:  a.XSSLClientNotAfter,
				XSSLSubjectDN:       a.XSSLSubjectDN,
				XSSLIssuerDN:        a.XSSLIssuerDN,
				XSSLClientSubjectDN: a.XSSLClientSubjectDN,
				XSSLClientIssuerDN:  a.XSSLClientIssuerDN,
				XSSLProtocol:        a.XSSLProtocol,
				XSSLCipher:          a.XSSLCipher,
			},
		}

		<-finished
	}()
}

// haveMonitoringFlag checks if the provided flag exists in the MonitoringFlags slice of the Authentication object.
// It iterates over the MonitoringFlags slice and returns true if the flag is found, otherwise it returns false.
func (a *Authentication) haveMonitoringFlag(flag global.Monitoring) bool {
	for _, setFlag := range a.MonitoringFlags {
		if setFlag == flag {
			return true
		}
	}

	return false
}

// handlePassword handles the authentication process for the password flow.
// It performs common validation checks and then proceeds based on the value of ctx.Value(global.CtxLocalCacheAuthKey).
// If it is true, it calls the handleLocalCache function.
// Otherwise, it calls the handleBackendTypes function to determine the cache usage, backend position, and password databases.
// In the next step, it calls the postVerificationProcesses function to perform further control flow based on cache usage and authentication status.
// Finally, it returns the authResult which indicates the authentication result of the process.
func (a *Authentication) handlePassword(ctx *gin.Context) (authResult global.AuthResult) {
	// Common validation checks
	if authResult = a.usernamePasswordChecks(); authResult != global.AuthResultUnset {
		return
	}

	if !(a.haveMonitoringFlag(global.MonInMemory) || a.isMasterUser()) && ctx.GetBool(global.CtxLocalCacheAuthKey) {
		return a.handleLocalCache(ctx)
	}

	useCache, backendPos, passDBs := a.handleBackendTypes()

	// Further control flow based on whether cache is used and authentication status
	authResult = a.postVerificationProcesses(ctx, useCache, backendPos, passDBs)

	return authResult
}

// usernamePasswordChecks performs checks on the Username and Password fields of the Authentication object.
// It logs debug messages for empty username or empty password cases.
// It returns global.AuthResultEmptyUsername if the username is empty.
// It returns global.AuthResultEmptyPassword if the password is empty.
// Otherwise, it returns global.AuthResultUnset.
// Usage example:
//
//	func (a *Authentication) handlePassword(ctx *gin.Context) (authResult global.AuthResult) {
//		a.usernamePasswordChecks()
//		...
//	}
//
// Dependencies:
// - util.DebugModule
// - global.AuthResult
// - global.DbgAuth
// - global.LogKeyGUID
// - global.LogKeyMsg
func (a *Authentication) usernamePasswordChecks() global.AuthResult {
	if a.Username == "" {
		util.DebugModule(global.DbgAuth, global.LogKeyGUID, a.GUID, global.LogKeyMsg, "Empty username")

		return global.AuthResultEmptyUsername
	}

	if !a.NoAuth && a.Password == "" {
		util.DebugModule(global.DbgAuth, global.LogKeyGUID, a.GUID, global.LogKeyMsg, "Empty password")

		return global.AuthResultEmptyPassword
	}

	return global.AuthResultUnset
}

// handleLocalCache handles the local cache authentication logic for the Authentication object.
// It sets the operation mode and initializes the passDBResult.
// Then, it filters the authentication result through the Lua filter.
// After that, the postLuaAction is executed on the passDBResult.
// Finally, it returns the authResult of type global.AuthResult.
func (a *Authentication) handleLocalCache(ctx *gin.Context) global.AuthResult {
	a.setOperationMode(ctx)

	passDBResult := a.initializePassDBResult()
	authResult := a.filterLua(passDBResult, ctx)

	a.postLuaAction(passDBResult)

	return authResult
}

// initializePassDBResult initializes a new instance of PassDBResult with values from the Authentication object.
// It sets Authenticated and UserFound to true and copies the values of AccountField, TOTPSecretField, TOTPRecoveryField,
// UniqueUserIDField, DisplayNameField, Backend, and Attributes from the Authentication object.
// The initialized PassDBResult instance is returned.
func (a *Authentication) initializePassDBResult() *PassDBResult {
	return &PassDBResult{
		Authenticated:     true,
		UserFound:         true,
		AccountField:      a.AccountField,
		TOTPSecretField:   a.TOTPSecretField,
		TOTPRecoveryField: a.TOTPRecoveryField,
		UniqueUserIDField: a.UniqueUserIDField,
		DisplayNameField:  a.DisplayNameField,
		Backend:           a.UsedPassDBBackend,
		Attributes:        a.Attributes,
	}
}

// handleBackendTypes initializes and populates variables related to backend types.
// The `backendPos` map stores the position of each backend type in the configuration list.
// The `useCache` boolean indicates whether the Cache backend type is used. It is set to true if at least one Cache backend is found in the configuration.
// The `passDBs` slice holds the PassDBMap objects associated with each backend type in the configuration.
// This method loops through the `config.LoadableConfig.Server.Backends` slice and processes each Backend object to determine the backend type. It populates the `backendPos` map with the backend type
func (a *Authentication) handleBackendTypes() (useCache bool, backendPos map[global.Backend]int, passDBs []*PassDBMap) {
	backendPos = make(map[global.Backend]int)

	for index, backendType := range config.LoadableConfig.Server.Backends {
		db := backendType.Get()
		switch db {
		case global.BackendCache:
			if !(a.haveMonitoringFlag(global.MonCache) || a.isMasterUser()) {
				passDBs = a.appendBackend(passDBs, global.BackendCache, cachePassDB)
				useCache = true
			}
		case global.BackendLDAP:
			if !config.LoadableConfig.LDAPHavePoolOnly() {
				passDBs = a.appendBackend(passDBs, global.BackendLDAP, ldapPassDB)
			}
		case global.BackendLua:
			passDBs = a.appendBackend(passDBs, global.BackendLua, luaPassDB)
		case global.BackendUnknown:
		case global.BackendLocalCache:
		}

		backendPos[db] = index
	}

	return useCache, backendPos, passDBs
}

// appendBackend appends a new PassDBMap object to the passDBs slice.
// Parameters:
// - passDBs: the slice of PassDBMap objects to append to
// - backendType: the global.Backend value representing the backend type
// - backendFunction: the PassDBOption function to assign to the PassDBMap object
// Returns:
// - The modified passDBs slice with the new PassDBMap object appended
func (a *Authentication) appendBackend(passDBs []*PassDBMap, backendType global.Backend, backendFunction PassDBOption) []*PassDBMap {
	return append(passDBs, &PassDBMap{
		backendType,
		backendFunction,
	})
}

// postVerificationProcesses manages the post-verification steps in the authentication process.
// It first verifies the password provided by the user. If the verification fails, it logs the error and returns temporary failure.
// If the cache is being used and the user is not excluded from authentication, it ensures that the cache backend precedes the used backend.
// If the verification is successful, user data is saved to Redis. If it fails, it increases the brute force counter.
// It then tries to get all password histories of the user. If the user is not found, it updates the brute force buckets counter,
// call post Lua action and return authentication failure.
// It also checks if the user is found during password verification, if true, it sets a new username to the user.
// Afterward, it applies a Lua filter to the result and calls the post Lua action, and finally, it returns the authentication result.
func (a *Authentication) postVerificationProcesses(ctx *gin.Context, useCache bool, backendPos map[global.Backend]int, passDBs []*PassDBMap) global.AuthResult {
	passDBResult, err := a.verifyPassword(passDBs)
	if err != nil {
		var detailedError *errors2.DetailedError

		if errors.As(err, &detailedError) {
			logs := []any{
				global.LogKeyGUID, a.GUID,
				global.LogKeyError, detailedError.Error(),
				global.LogKeyErrorDetails, detailedError.GetDetails(),
			}

			if len(a.AdditionalLogs) > 0 && len(a.AdditionalLogs)%2 == 0 {
				logs = append(logs, a.AdditionalLogs...)
			}

			level.Error(logging.DefaultErrLogger).Log(logs...)
		} else {
			level.Error(logging.DefaultErrLogger).Log(global.LogKeyGUID, a.GUID, global.LogKeyError, err.Error())
		}

		return global.AuthResultTempFail
	}

	if useCache && !a.NoAuth {
		// Make sure the cache backend is in front of the used backend.
		if passDBResult.Authenticated {
			if backendPos[global.BackendCache] < backendPos[a.UsedPassDBBackend] {
				var usedBackend global.CacheNameBackend

				switch a.UsedPassDBBackend {
				case global.BackendLDAP:
					usedBackend = global.CacheLDAP
				case global.BackendLua:
					usedBackend = global.CacheLua
				case global.BackendUnknown:
				case global.BackendCache:
				case global.BackendLocalCache:
				}

				cacheNames := backend.GetCacheNames(a.Protocol.Get(), usedBackend)

				for _, cacheName := range cacheNames.GetStringSlice() {
					var accountName string

					accountName, err = a.getUserAccountFromRedis()
					if err != nil {
						level.Error(logging.DefaultErrLogger).Log(global.LogKeyGUID, a.GUID, global.LogKeyError, err.Error())

						return global.AuthResultTempFail
					}

					if accountName != "" {
						redisUserKey := config.LoadableConfig.Server.Redis.Prefix + "ucp:" + cacheName + ":" + accountName
						ppc := &backend.PositivePasswordCache{
							AccountField:      a.AccountField,
							TOTPSecretField:   a.TOTPSecretField,
							UniqueUserIDField: a.UniqueUserIDField,
							DisplayNameField:  a.DisplayNameField,
							Password: func() string {
								if a.Password != "" {
									return util.GetHash(util.PreparePassword(a.Password))
								}

								return a.Password
							}(),
							Backend:    a.SourcePassDBBackend,
							Attributes: a.Attributes,
						}

						go func() {
							if err := backend.SaveUserDataToRedis(*a.GUID, redisUserKey, config.LoadableConfig.Server.Redis.PosCacheTTL, ppc); err == nil {
								stats.RedisWriteCounter.Inc()
							}
						}()
					}
				}
			}
		} else {
			util.DebugModule(
				global.DbgAuth,
				global.LogKeyGUID, a.GUID,
				"authenticated", false,
				global.LogKeyMsg, "Calling saveBruteForcePasswordToRedis()",
			)

			// Increase counters
			a.saveBruteForcePasswordToRedis()
		}

		a.getAllPasswordHistories()
	}

	if !passDBResult.Authenticated {
		a.updateBruteForceBucketsCounter()

		authResult := a.filterLua(passDBResult, ctx)

		a.postLuaAction(passDBResult)

		return authResult
	}

	// Set new username
	if passDBResult.UserFound {
		if passDBResult.AccountField != nil {
			a.AccountField = passDBResult.AccountField
			a.UsernameReplace = true
		}
	}

	if passDBResult.Authenticated {
		if !(a.haveMonitoringFlag(global.MonInMemory) || a.isMasterUser()) {
			localcache.LocalCache.Set(a.generateLocalChacheKey(), a, config.EnvConfig.LocalCacheAuthTTL)
		}
	}

	authResult := a.filterLua(passDBResult, ctx)

	a.postLuaAction(passDBResult)

	return authResult
}

// filterLua calls Lua filters which can change the backend result.
func (a *Authentication) filterLua(passDBResult *PassDBResult, ctx *gin.Context) global.AuthResult {
	if !config.LoadableConfig.HaveLuaFilters() {
		if passDBResult.Authenticated {
			return global.AuthResultOK
		}

		return global.AuthResultFail
	}

	timer := prometheus.NewTimer(stats.FunctionDuration.WithLabelValues("Filter", "filterLua"))

	defer timer.ObserveDuration()

	BackendServers.mu.RLock()

	backendServers := BackendServers.backendServer

	util.DebugModule(global.DbgFeature, global.LogKeyMsg, fmt.Sprintf("Active backend servers: %d", len(backendServers)))

	BackendServers.mu.RUnlock()

	filterRequest := &filter.Request{
		BackendServers:     backendServers,
		UsedBackendAddress: &a.UsedBackendIP,
		UsedBackendPort:    &a.UsedBackendPort,
		Logs:               nil,
		Context:            a.Context,
		CommonRequest: &lualib.CommonRequest{
			Debug:             config.LoadableConfig.Server.Log.Level.Level() == global.LogLevelDebug,
			Repeating:         false, // unavailable
			UserFound:         passDBResult.UserFound,
			Authenticated:     passDBResult.Authenticated,
			NoAuth:            a.NoAuth,
			BruteForceCounter: 0, // unavailable
			Service:           a.Service,
			Session:           *a.GUID,
			ClientIP:          a.ClientIP,
			ClientPort:        a.XClientPort,
			ClientNet:         "", // unavailable
			ClientHost:        a.ClientHost,
			ClientID:          a.XClientID,
			UserAgent:         *a.UserAgent,
			LocalIP:           a.XLocalIP,
			LocalPort:         a.XPort,
			Username:          a.Username,
			Account: func() string {
				if passDBResult.UserFound {
					return a.getAccount()
				}

				return ""
			}(),
			UniqueUserID:        a.getUniqueUserID(),
			DisplayName:         a.getDisplayName(),
			Password:            a.Password,
			Protocol:            a.Protocol.String(),
			BruteForceName:      "", // unavailable
			FeatureName:         "", // unavailable
			StatusMessage:       &a.StatusMessage,
			XSSL:                a.XSSL,
			XSSLSessionID:       a.XSSLSessionID,
			XSSLClientVerify:    a.XSSLClientVerify,
			XSSLClientDN:        a.XSSLClientDN,
			XSSLClientCN:        a.XSSLClientCN,
			XSSLIssuer:          a.XSSLIssuer,
			XSSLClientNotBefore: a.XSSLClientNotBefore,
			XSSLClientNotAfter:  a.XSSLClientNotAfter,
			XSSLSubjectDN:       a.XSSLSubjectDN,
			XSSLIssuerDN:        a.XSSLIssuerDN,
			XSSLClientSubjectDN: a.XSSLClientSubjectDN,
			XSSLClientIssuerDN:  a.XSSLClientIssuerDN,
			XSSLProtocol:        a.XSSLProtocol,
			XSSLCipher:          a.XSSLCipher,
		},
	}

	filterResult, luaBackendResult, err := filterRequest.CallFilterLua(ctx)
	if err != nil {
		if !errors.Is(err, errors2.ErrNoFiltersDefined) {
			level.Error(logging.DefaultErrLogger).Log(global.LogKeyGUID, a.GUID, global.LogKeyError, err.Error())

			return global.AuthResultTempFail
		}
	} else {
		for index := range *filterRequest.Logs {
			a.AdditionalLogs = append(a.AdditionalLogs, (*filterRequest.Logs)[index])
		}

		if statusMessage := filterRequest.StatusMessage; *statusMessage != a.StatusMessage {
			a.StatusMessage = *statusMessage
		}

		if filterResult {
			return global.AuthResultFail
		}

		if luaBackendResult != nil {
			// XXX: We currently only support changing attributes from the Authentication object.
			if (*luaBackendResult).Attributes != nil {
				for key, value := range (*luaBackendResult).Attributes {
					if keyName, assertOk := key.(string); assertOk {
						if _, okay := a.Attributes[keyName]; !okay {
							a.Attributes[keyName] = []any{value}
						}
					}
				}
			}
		}

		a.UsedBackendIP = *filterRequest.UsedBackendAddress
		a.UsedBackendPort = *filterRequest.UsedBackendPort
	}

	if passDBResult.Authenticated {
		return global.AuthResultOK
	}

	return global.AuthResultFail
}

// listUserAccounts returns the list of all known users from the account databases.
func (a *Authentication) listUserAccounts() (accountList AccountList) {
	var accounts []*AccountListMap

	for _, backendType := range config.LoadableConfig.Server.Backends {
		switch backendType.Get() {
		case global.BackendLDAP:
			if !config.LoadableConfig.LDAPHavePoolOnly() {
				accounts = append(accounts, &AccountListMap{
					global.BackendLDAP,
					ldapAccountDB,
				})
			}
		case global.BackendLua:
			accounts = append(accounts, &AccountListMap{
				global.BackendLua,
				luaAccountDB,
			})
		case global.BackendUnknown:
		case global.BackendCache:
		case global.BackendLocalCache:
		}
	}

	for _, accountDB := range accounts {
		result, err := accountDB.fn(a)

		util.DebugModule(global.DbgAuth, global.LogKeyGUID, a.GUID, "backendType", accountDB.backend.String(), "result", fmt.Sprintf("%v", result))

		if err == nil {
			accountList = append(accountList, result...)
		} else {
			var detailedError *errors2.DetailedError
			if errors.As(err, &detailedError) {
				level.Error(logging.DefaultErrLogger).Log(
					global.LogKeyGUID, a.GUID,
					global.LogKeyError, detailedError.Error(),
					global.LogKeyErrorDetails, detailedError.GetDetails())
			} else {
				level.Error(logging.DefaultErrLogger).Log(global.LogKeyGUID, a.GUID, global.LogKeyError, err)
			}
		}
	}

	return accountList
}

// String returns the string for a PassDBResult object.
func (p PassDBResult) String() string {
	var result string

	value := reflect.ValueOf(p)
	typeOfValue := value.Type()

	for index := range value.NumField() {
		result += fmt.Sprintf(" %s='%v'", typeOfValue.Field(index).Name, value.Field(index).Interface())
	}

	return result[1:]
}

// getUserAccountFromRedis returns the user account value from the user Redis hash. If none was found, a new entry in
// the hash table is created.
func (a *Authentication) getUserAccountFromRedis() (accountName string, err error) {
	var (
		assertOk bool
		accounts []string
		values   []any
	)

	key := config.LoadableConfig.Server.Redis.Prefix + global.RedisUserHashKey

	accountName, err = backend.LookupUserAccountFromRedis(a.Username)
	if err != nil {
		return
	} else {
		stats.RedisReadCounter.Inc()
	}

	if accountName != "" {
		return
	}

	if a.AccountField != nil {
		if values, assertOk = a.Attributes[*a.AccountField]; !assertOk {
			return "", errors2.ErrNoAccount
		}

		for index := range values {
			accounts = append(accounts, values[index].(string))
		}

		sort.Sort(sort.StringSlice(accounts))

		accountName = strings.Join(accounts, ":")

		err = rediscli.WriteHandle.HSet(context.Background(), key, a.Username, accountName).Err()
		if err == nil {
			stats.RedisWriteCounter.Inc()
		}
	}

	return
}

// setOperationMode sets the operation mode of the Authentication object based on the "mode" query parameter from the provided gin context.
// It retrieves the GUID from the gin context and uses it for logging purposes.
// The operation mode can be "no-auth" or "list-accounts".
// If the mode is "no-auth", it sets the NoAuth field of the Authentication object to true.
// If the mode is "list-accounts", it sets the ListAccounts field of the Authentication object to true.
// The function "util.DebugModule" is used for logging debug messages with the appropriate module name and function name.
// Example usage of setOperationMode:
//
//	a.setOperationMode(ctx)
//
//	func setupAuth(ctx *gin.Context, auth *Authentication) {
//	  //...
//	  auth.setOperationMode(ctx)
//	}
func (a *Authentication) setOperationMode(ctx *gin.Context) {
	guid := ctx.GetString(global.CtxGUIDKey)

	switch ctx.Query("mode") {
	case "no-auth":
		util.DebugModule(global.DbgAuth, global.LogKeyGUID, guid, global.LogKeyMsg, "mode=no-auth")

		a.NoAuth = true
	case "list-accounts":
		util.DebugModule(global.DbgAuth, global.LogKeyGUID, guid, global.LogKeyMsg, "mode=list-accounts")

		a.ListAccounts = true
	}

	if ctx.Query("in-memory") == "0" {
		a.MonitoringFlags = append(a.MonitoringFlags, global.MonInMemory)
	}

	if ctx.Query("cache") == "0" {
		a.MonitoringFlags = append(a.MonitoringFlags, global.MonCache)
	}
}

// setupHeaderBasedAuth sets up the authentication based on the headers in the request.
// It takes the context and the authentication object as parameters.
// It retrieves the GUID value from the context using global.CtxGUIDKey and casts it to a string.
// It retrieves the "Auth-User" and "Auth-Pass" headers from the request and assigns them to the username and password fields of the authentication object.
// It sets the protocol field of the authentication object by calling the Set method on auth.Protocol with the value of the "Auth-Protocol" header.
// It parses the "Auth-Login-Attempt" header as an integer and assigns it to the loginAttempts variable.
// If there is an error parsing the header or the loginAttempts is negative, it sets loginAttempts to 0.
// It assigns the loginAttempts value to the LoginAttempts field of the authentication object using an immediately invoked function expression (IIFE).
// It retrieves the "Auth-Method" header from the request and assigns it to the method variable.
// It checks the "mode" query parameter in the context.
// If it is set to "no-auth", it sets the NoAuth field of the authentication object to true.
// If it is set to "list-accounts", it sets the ListAccounts field of the authentication object to true.
// It calls the withClientInfo, withLocalInfo, withUserAgent, and withXSSL methods on the authentication object to set additional fields based on the context.
func setupHeaderBasedAuth(ctx *gin.Context, auth *Authentication) {
	// Nginx header, see: https://nginx.org/en/docs/mail/ngx_mail_auth_http_module.html#protocol
	auth.Username = ctx.GetHeader("Auth-User")
	auth.UsernameOrig = auth.Username
	auth.Password = ctx.GetHeader("Auth-Pass")

	encoded := ctx.GetHeader("X-Auth-Password-Encoded")
	if encoded == "1" {
		padding := len(auth.Password) % 4
		if padding > 0 {
			auth.Password += string(bytes.Repeat([]byte("="), 4-padding))
		}

		if password, err := base64.URLEncoding.DecodeString(auth.Password); err != nil {
			auth.Password = ""

			ctx.Error(errors2.ErrPasswordEncoding)
		} else {
			auth.Password = string(password)
		}
	}

	auth.Protocol.Set(ctx.GetHeader("Auth-Protocol"))

	auth.LoginAttempts = func() uint {
		loginAttempts, err := strconv.Atoi(ctx.GetHeader("Auth-Login-Attempt"))
		if err != nil {
			return 0
		}

		if loginAttempts < 0 {
			loginAttempts = 0
		}

		return uint(loginAttempts)
	}()

	method := ctx.GetHeader("Auth-Method")

	auth.Method = &method

	auth.withClientInfo(ctx)
	auth.withLocalInfo(ctx)
	auth.withUserAgent(ctx)
	auth.withXSSL(ctx)
}

// processApplicationXWWWFormUrlencoded processes the application/x-www-form-urlencoded data from the request context and updates the Authentication object.
// It extracts the values for the fields method, realm, user_agent, username, password, protocol, port, tls, and security from the request form.
// If the realm field is not empty, it appends "@" + realm to the username field in the Authentication object.
// It sets the method, user_agent, username, usernameOrig, password, protocol, xLocalIP, xPort, xSSL, and xSSLProtocol fields in the Authentication object.
func processApplicationXWWWFormUrlencoded(ctx *gin.Context, auth *Authentication) {
	method := ctx.PostForm("method")
	realm := ctx.PostForm("realm")
	userAgent := ctx.PostForm("user_agent")

	if len(realm) > 0 {
		auth.Username += "@" + realm
	}

	auth.Method = &method
	auth.UserAgent = &userAgent
	auth.Username = ctx.PostForm("username")
	auth.UsernameOrig = auth.Username
	auth.Password = ctx.PostForm("password")
	auth.Protocol = &config.Protocol{}
	auth.Protocol.Set(ctx.PostForm("protocol"))
	auth.XLocalIP = global.Localhost4
	auth.XPort = ctx.PostForm("port")
	auth.XSSL = ctx.PostForm("tls")
	auth.XSSLProtocol = ctx.PostForm("security")

	if !util.ValidateUsername(auth.Username) {
		auth.Username = ""

		ctx.Error(errors2.ErrInvalidUsername)
	}
}

// processApplicationJSON takes a gin Context and an Authentication object.
// It attempts to bind the JSON payload from the Context to a JSONRequest object.
// If there is an error in the binding process, it sets the error type to "gin.ErrorTypeBind" and returns.
// Otherwise, it calls the setAuthenticationFields function with the Authentication object and the JSONRequest object,
// and sets additional fields in the Authentication object using the XSSL method.
func processApplicationJSON(ctx *gin.Context, auth *Authentication) {
	var jsonRequest *JSONRequest

	err := ctx.ShouldBindJSON(&jsonRequest)
	if err != nil {
		ctx.Error(errors2.ErrInvalidJSONPayload).SetType(gin.ErrorTypeBind)

		return
	}

	setAuthenticationFields(auth, jsonRequest).withXSSL(ctx)
}

// setAuthenticationFields populates the fields of the Authentication struct with values from the JSONRequest.
// It takes a pointer to the Authentication struct and a pointer to the JSONRequest struct as input.
// It sets the values of the Method, UserAgent, Username, UsernameOrig, Password, ClientIP, XClientPort,
// ClientHost, XLocalIP, XPort, and Service fields of the Authentication struct with the corresponding values
// from the JSONRequest struct.
// It then returns the pointer to the modified Authentication struct.
//
// Example usage:
// auth := &Authentication{}
//
//	request := &JSONRequest{
//	    Method:          "POST",
//	    ClientID:        "client123",
//	    Username:        "john",
//	    Password:        "password",
//	    ClientIP:        "192.168.1.100",
//	    ClientPort:      "8080",
//	    ClientHostname:  "example.com",
//	    LocalIP:         "127.0.0.1",
//	    LocalPort:       "3000",
//	    Service:         "auth",
//	    AuthLoginAttempt: 1,
//	}
//
// setAuthenticationFields(auth, request)
// // After the function call, the fields of auth would be populated with the values from request
func setAuthenticationFields(auth *Authentication, request *JSONRequest) *Authentication {
	auth.Method = &request.Method
	auth.UserAgent = &request.ClientID
	auth.Username = request.Username
	auth.UsernameOrig = request.Username
	auth.Password = request.Password
	auth.ClientIP = request.ClientIP
	auth.XClientPort = request.ClientPort
	auth.ClientHost = request.ClientHostname
	auth.XLocalIP = request.LocalIP
	auth.XPort = request.LocalPort
	auth.Service = request.Service

	return auth
}

// setupBodyBasedAuth takes a Context and an Authentication object as input.
// It retrieves the "Content-Type" header from the Context.
// If the "Content-Type" starts with "application/x-www-form-urlencoded",
// it calls the processApplicationXWWWFormUrlencoded function passing the Context and Authentication object.
// If the "Content-Type" is "application/json",
// it calls the processApplicationJSON function passing the Context and Authentication object.
// If neither of the above conditions match, it sets the error associated with unsupported media type
// and sets the error type to gin.ErrorTypeBind on the Context.
func setupBodyBasedAuth(ctx *gin.Context, auth *Authentication) {
	contentType := ctx.GetHeader("Content-Type")

	if strings.HasPrefix(contentType, "application/x-www-form-urlencoded") {
		processApplicationXWWWFormUrlencoded(ctx, auth)
	} else if contentType == "application/json" {
		processApplicationJSON(ctx, auth)
	} else {
		ctx.Error(errors2.ErrUnsupportedMediaType).SetType(gin.ErrorTypeBind)
	}
}

// setupHTTPBasiAuth sets up basic authentication for HTTP requests.
// It takes in a gin.Context object and a pointer to an Authentication object.
// It calls the withClientInfo, withLocalInfo, withUserAgent, and withXSSL methods of the Authentication object to set client, local, user-agent, and X-SSL information, respectively
func setupHTTPBasiAuth(ctx *gin.Context, auth *Authentication) {
	// NOTE: We must get username and password later!
	auth.withClientInfo(ctx)
	auth.withLocalInfo(ctx)
	auth.withUserAgent(ctx)
	auth.withXSSL(ctx)
}

// setupAuth sets up the authentication based on the service parameter in the gin context.
// It takes the gin context and an Authentication struct as input.
//
// If the service parameter is "nginx", "dovecot", or "user", it calls the setupHeaderBasedAuth function.
// If the service parameter is "saslauthd", it calls the setupBodyBasedAuth function.
// If the service parameter is "basicauth", it calls the setupHTTPBasiAuth function.
//
// After setting up the authentication, it calls the withDefaults method on the Authentication struct.
//
// Example usage:
//
//	auth := &Authentication{}
//	ctx := gin.Context{}
//	ctx.SetParam("service", "nginx")
//	setupAuth(&ctx, auth)
func setupAuth(ctx *gin.Context, auth *Authentication) {
	auth.Protocol = &config.Protocol{}

	switch ctx.Param("service") {
	case global.ServNginx, global.ServDovecot, global.ServUserInfo:
		setupHeaderBasedAuth(ctx, auth)
	case global.ServSaslauthd, global.ServJSON:
		setupBodyBasedAuth(ctx, auth)
	case global.ServBasicAuth:
		setupHTTPBasiAuth(ctx, auth)
	}

	if !util.ValidateUsername(auth.Username) {
		auth.Username = ""

		ctx.Error(errors2.ErrInvalidUsername)
	}

	auth.withDefaults(ctx)

	auth.setOperationMode(ctx)
}

// NewAuthentication creates a new instance of the Authentication struct.
// It takes a gin.Context object as a parameter and sets it as the HTTPClientContext field of the Authentication struct.
// If an error occurs while setting the StatusCode field using the setStatusCodes function, it logs the error and returns nil.
// Otherwise, it calls the setupAuth function to setup the Authentication struct based on the service parameter from the gin.Context object.
// Finally, it returns the created Authentication struct.
func NewAuthentication(ctx *gin.Context) *Authentication {
	auth := &Authentication{
		HTTPClientContext: ctx.Copy(),
	}

	if err := auth.setStatusCodes(ctx.Param("service")); err != nil {
		guid := ctx.GetString(global.CtxGUIDKey)

		level.Error(logging.DefaultErrLogger).Log(global.LogKeyGUID, guid, global.LogKeyError, err)

		return nil
	}

	setupAuth(ctx, auth)

	if ctx.Errors.Last() != nil {
		return nil
	}

	return auth
}

// withDefaults sets default values for the Authentication structure including the GUID session value.
func (a *Authentication) withDefaults(ctx *gin.Context) *Authentication {
	if a == nil {
		return nil
	}

	guidStr := ctx.GetString(global.CtxGUIDKey)

	a.GUID = &guidStr
	a.UsedPassDBBackend = global.BackendUnknown
	a.PasswordsAccountSeen = 0
	a.Service = ctx.Param("service")
	a.Context = ctx.MustGet(global.CtxDataExchangeKey).(*lualib.Context)

	if a.Protocol.Get() == "" {
		a.Protocol.Set(global.ProtoDefault)
	}

	return a
}

// withLocalInfo adds the local IP and -port headers to the Authentication structure.
func (a *Authentication) withLocalInfo(ctx *gin.Context) *Authentication {
	if a == nil {
		return nil
	}

	a.XLocalIP = ctx.GetHeader("X-Local-IP")
	a.XPort = ctx.GetHeader("X-Auth-Port")

	return a
}

// withClientInfo adds the client IP, -port and -ID headers to the Authentication structure.
func (a *Authentication) withClientInfo(ctx *gin.Context) *Authentication {
	var err error

	if a == nil {
		return nil
	}

	a.ClientIP = ctx.GetHeader("Client-IP")
	a.XClientPort = ctx.GetHeader("X-Client-Port")
	a.XClientID = ctx.GetHeader("X-Client-Id")

	if a.ClientIP == "" {
		// This might be valid, if HAproxy v2 support is enabled
		a.ClientIP, a.XClientPort, err = net.SplitHostPort(ctx.Request.RemoteAddr)
		if err != nil {
			level.Error(logging.DefaultErrLogger).Log(global.LogKeyGUID, a.GUID, global.LogKeyError, err.Error())
		}

		a.ClientIP, a.XClientPort = util.GetProxyAddress(ctx.Request, a.ClientIP, a.XClientPort)
	}

	if config.LoadableConfig.Server.DNS.ResolveClientIP {
		a.ClientHost = util.ResolveIPAddress(ctx, a.ClientIP)
	}

	if a.ClientHost == "" {
		// Fallback to environment variable
		a.ClientHost = ctx.GetHeader("Client-Host")
	}

	return a
}

// withUserAgent adds the User-Agent header to the Authentication structure.
func (a *Authentication) withUserAgent(ctx *gin.Context) *Authentication {
	if a == nil {
		return nil
	}

	userAgent := ctx.Request.UserAgent()

	a.UserAgent = &userAgent

	return a
}

// withXSSL adds HAProxy header processing to the Authentication structure.
func (a *Authentication) withXSSL(ctx *gin.Context) *Authentication {
	if a == nil {
		return nil
	}

	a.XSSL = util.CheckStrings(
		ctx.GetHeader("Auth-SSL"), ctx.GetHeader("X-SSL"))
	a.XSSLSessionID = util.CheckStrings(ctx.GetHeader("X-SSL-Session-ID"))
	a.XSSLClientVerify = util.CheckStrings(
		ctx.GetHeader("Auth-SSL-Verify"), ctx.GetHeader("X-SSL-Client-Verify"))
	a.XSSLClientDN = util.CheckStrings(
		ctx.GetHeader("Auth-SSL-Subject"), ctx.GetHeader("X-SSL-Client-DN"))
	a.XSSLClientCN = util.CheckStrings(ctx.GetHeader("X-SSL-Client-CN"))
	a.XSSLIssuer = util.CheckStrings(ctx.GetHeader("X-SSL-Issuer"))
	a.XSSLClientNotBefore = util.CheckStrings(ctx.GetHeader("X-SSL-Client-NotBefore"))
	a.XSSLClientNotAfter = util.CheckStrings(ctx.GetHeader("X-SSL-Client-NotAfter"))
	a.XSSLSubjectDN = util.CheckStrings(ctx.GetHeader("X-SSL-Subject-DN"))
	a.XSSLIssuerDN = util.CheckStrings(
		ctx.GetHeader("Auth-SSL-Issuer"), ctx.GetHeader("X-SSL-Issuer-DN"))
	a.XSSLClientSubjectDN = util.CheckStrings(ctx.GetHeader("X-SSL-Client-Subject-DN"))
	a.XSSLClientIssuerDN = util.CheckStrings(ctx.GetHeader("X-SSL-Client-Issuer-DN"))
	a.XSSLCipher = util.CheckStrings(
		ctx.GetHeader("Auth-SSL-Cipher"), ctx.GetHeader("X-SSL-Cipher"))
	a.XSSLProtocol = util.CheckStrings(
		ctx.GetHeader("Auth-SSL-Protocol"), ctx.GetHeader("X-SSL-Protocol"))

	// TODO: Nginx: Auth-SSL-Serial, Auth-SSL-Fingerprint

	return a
}

// processClaim processes a claim and updates the claims map with the claimName and claimValue.
// If the claimValue is not empty and found in the Attributes map of the Authentication object,
// the claimValue is set in the claims map with the claimName as key.
// Otherwise, a warning is logged.
//
// Parameters:
// - claimName: The name of the claim to process.
// - claimValue: The value of the claim to process.
// - claims: The map to update with the processed claim.
func (a *Authentication) processClaim(claimName string, claimValue string, claims map[string]any) {
	if claimValue != "" {
		if value, found := a.Attributes[claimValue]; found {
			if arg, assertOk := value[global.SliceWithOneElement].(string); assertOk {
				claims[claimName] = arg

				return
			}
		}

		level.Warn(logging.DefaultLogger).Log(
			global.LogKeyGUID, a.GUID,
			global.LogKeyWarning, fmt.Sprintf("Claim '%s' malformed or not returned from database", claimName),
		)
	}
}

// Custom logic to apply string claims
func applyClaim(claimKey string, attributeKey string, a *Authentication, claims map[string]any, claimHandlers []ClaimHandler) {
	var success bool

	if attributeValue, found := a.Attributes[attributeKey]; found {
		for _, handler := range claimHandlers {
			if t := reflect.TypeOf(attributeValue).Kind(); t == handler.Type {
				success = handler.ApplyFunc(attributeValue, claims, claimKey)
				if success {
					break
				}
			}
		}
	}

	if !success {
		level.Warn(logging.DefaultLogger).Log(
			global.LogKeyGUID, a.GUID,
			global.LogKeyWarning, fmt.Sprintf("Claim '%s' malformed or not returned from Database", claimKey),
		)
	}
}

// processClientClaims processes the client claims by iterating over a map of claim names and values.
// The claim names and corresponding values to process are defined in the claimChecks map.
// For each claim, it calls the processClaim method to apply any necessary processing logic and update the claims map.
// Finally, it returns the updated claims map.
//
// Parameters:
// - client: a pointer to the config.Oauth2Client structure representing the client configuration
// - claims: a map[string]any representing the client claims
//
// Returns:
// - a map[string]any representing the updated client claims
//
// Example usage:
//
//	clientClaims := make(map[string]any)
//	updatedClaims := a.processClientClaims(&oauth2Client, clientClaims)
//	fmt.Println(updatedClaims)
func (a *Authentication) processClientClaims(client *config.Oauth2Client, claims map[string]any) map[string]any {
	// Claim names to process
	claimChecks := map[string]string{
		global.ClaimName:              client.Claims.Name,
		global.ClaimGivenName:         client.Claims.GivenName,
		global.ClaimFamilyName:        client.Claims.FamilyName,
		global.ClaimMiddleName:        client.Claims.MiddleName,
		global.ClaimNickName:          client.Claims.NickName,
		global.ClaimPreferredUserName: client.Claims.PreferredUserName,
		global.ClaimProfile:           client.Claims.Profile,
		global.ClaimWebsite:           client.Claims.Website,
		global.ClaimPicture:           client.Claims.Picture,
		global.ClaimEmail:             client.Claims.Email,
		global.ClaimGender:            client.Claims.Gender,
		global.ClaimBirtDate:          client.Claims.Birthdate,
		global.ClaimZoneInfo:          client.Claims.ZoneInfo,
		global.ClaimLocale:            client.Claims.Locale,
		global.ClaimPhoneNumber:       client.Claims.PhoneNumber,
	}

	for claimName, claimVal := range claimChecks {
		a.processClaim(claimName, claimVal, claims)
	}

	return claims
}

// applyClientClaimHandlers applies claim handlers to client claims and returns the modified claims.
func (a *Authentication) applyClientClaimHandlers(client *config.Oauth2Client, claims map[string]any) map[string]any {
	claimHandlers := []ClaimHandler{
		{
			Type: reflect.String,
			ApplyFunc: func(value any, claims map[string]any, claimKey string) bool {
				if strValue, ok := value.(string); ok {
					if claimKey == global.ClaimEmailVerified || claimKey == global.ClaimPhoneNumberVerified {
						if boolean, err := strconv.ParseBool(strValue); err == nil {
							claims[claimKey] = boolean

							return true
						}
					} else if claimKey == global.ClaimAddress {
						claims[claimKey] = struct {
							Formatted string `json:"formatted"`
						}{Formatted: strValue}

						return true
					}
				}

				return false
			},
		},
		{
			Type: reflect.Bool,
			ApplyFunc: func(value any, claims map[string]any, claimKey string) bool {
				if boolValue, ok := value.(bool); ok {
					claims[claimKey] = boolValue

					return true
				}

				return false
			},
		},
		{
			Type: reflect.Float64,
			ApplyFunc: func(value any, claims map[string]any, claimKey string) bool {
				if floatValue, ok := value.(float64); ok {
					claims[claimKey] = floatValue

					return true
				}

				return false
			},
		},
	}

	claimKeys := map[string]string{
		global.ClaimEmailVerified:       client.Claims.EmailVerified,
		global.ClaimPhoneNumberVerified: client.Claims.PhoneNumberVerified,
		global.ClaimAddress:             client.Claims.Address,
		global.ClaimUpdatedAt:           client.Claims.UpdatedAt,
	}

	for claimKey, attrKey := range claimKeys {
		if attrKey != "" {
			applyClaim(claimKey, attrKey, a, claims, claimHandlers)
		}
	}

	return claims
}

// processGroupsClaim processes the groups claim for the specified index in the OAuth2 clients configuration.
// It checks if the claim is defined and retrieves the corresponding value from the Authentication object's Attributes.
// If the value is found and is of type string, it adds it to the provided `claims` map with the key `ClaimGroups`.
// It sets the `valueApplied` flag to true if the value is successfully applied to the `claims` map.
// If the value is not found or is not of type string, it logs a warning message.
// The purpose of the method is to populate the groups claim in the `claims` map for the given OAuth2 client.
//
// Parameters:
// - index: The index of the OAuth2 client in the configuration.
// - claims: The `claims` map to populate with the groups claim.
//
// Example usage:
// ```go
// clientIndex := 0
// claims := make(map[string]any)
// authentication.processGroupsClaim(clientIndex, claims)
// ```
//
// Note: This method relies on the following declarations:
// - `config.LoadableConfig.Oauth2.Clients`: The OAuth2 clients configuration.
// - `a.Attributes`: The Authentication object's Attributes map.
// - `util.DebugModule`: A function for logging debug messages.
// - `global.DbgModule`, `global.LogKeyGUID`, `global.ClaimGroups`, `logging.DefaultLogger`, `global.LogKeyWarning`: Various declarations used internally in the method.
func (a *Authentication) processGroupsClaim(index int, claims map[string]any) {
	valueApplied := false

	if config.LoadableConfig.Oauth2.Clients[index].Claims.Groups != "" {
		if value, found := a.Attributes[config.LoadableConfig.Oauth2.Clients[index].Claims.Groups]; found {
			var stringSlice []string

			util.DebugModule(
				global.DbgAuth,
				global.LogKeyGUID, a.GUID,
				"groups", fmt.Sprintf("%#v", value),
			)

			for anyIndex := range value {
				if arg, assertOk := value[anyIndex].(string); assertOk {
					stringSlice = append(stringSlice, arg)
				}
			}

			claims[global.ClaimGroups] = stringSlice
			valueApplied = true
		}

		if !valueApplied {
			level.Warn(logging.DefaultLogger).Log(
				global.LogKeyGUID, a.GUID,
				global.LogKeyWarning, fmt.Sprintf("Claim '%s' malformed or not returned from Database", global.ClaimGroups),
			)
		}
	}
}

// processCustomClaims processes custom claims for a specific scope and OAuth2 client.
// It retrieves the custom claim names and types from the configuration and checks if
// the client has defined values for those claims. If so, it converts the claim value
// to the corresponding type and adds it to the claims map.
//
// Parameters:
// - scopeIndex: the index of the custom scope to process
// - oauth2Client: the OAuth2 client to process claims for
// - claims: the map to store the processed claims
//
// Example usage:
// ```
// auth := &Authentication{}
// processCustomClaims(0, oauth2Client, auth.Claims)
// ```
func (a *Authentication) processCustomClaims(scopeIndex int, oauth2Client openapi.OAuth2Client, claims map[string]any) {
	var claim any

	customScope := config.LoadableConfig.Oauth2.CustomScopes[scopeIndex]

	for claimIndex := range customScope.Claims {
		customClaimName := customScope.Claims[claimIndex].Name
		customClaimType := customScope.Claims[claimIndex].Type
		valueTypeMatch := false

		for clientIndex := range config.LoadableConfig.Oauth2.Clients {
			if config.LoadableConfig.Oauth2.Clients[clientIndex].ClientId != oauth2Client.GetClientId() {
				continue
			}

			assertOk := false
			if claim, assertOk = config.LoadableConfig.Oauth2.Clients[clientIndex].Claims.CustomClaims[customClaimName]; !assertOk {
				break
			}

			if claimValue, assertOk := claim.(string); assertOk {
				if value, found := a.Attributes[claimValue]; found {
					util.DebugModule(
						global.DbgAuth,
						global.LogKeyGUID, a.GUID,
						"custom_claim_name", customClaimName,
						"custom_claim_type", customClaimType,
						"value", fmt.Sprintf("%#v", value),
					)

					if customClaimType == global.ClaimTypeString {
						if arg, assertOk := value[global.SliceWithOneElement].(string); assertOk {
							claims[customClaimName] = arg
							valueTypeMatch = true
						}
					} else if customClaimType == global.ClaimTypeFloat {
						if arg, assertOk := value[global.SliceWithOneElement].(float64); assertOk {
							claims[customClaimName] = arg
							valueTypeMatch = true
						} else if arg, assertOk := value[global.SliceWithOneElement].(string); assertOk {
							if number, err := strconv.ParseFloat(arg, 64); err == nil {
								claims[customClaimName] = number
								valueTypeMatch = true
							}
						}
					} else if customClaimType == global.ClaimTypeInteger {
						if arg, assertOk := value[global.SliceWithOneElement].(int64); assertOk {
							claims[customClaimName] = arg
							valueTypeMatch = true
						} else if arg, assertOk := value[global.SliceWithOneElement].(string); assertOk {
							if number, err := strconv.ParseInt(arg, 0, 64); err == nil {
								claims[customClaimName] = number
								valueTypeMatch = true
							}
						}
					} else if customClaimType == global.ClaimTypeBoolean {
						if arg, assertOk := value[global.SliceWithOneElement].(bool); assertOk {
							claims[customClaimName] = arg
							valueTypeMatch = true
						} else if arg, assertOk := value[global.SliceWithOneElement].(string); assertOk {
							if boolean, err := strconv.ParseBool(arg); err == nil {
								claims[customClaimName] = boolean
								valueTypeMatch = true
							}
						}
					}
				}
			}

			if !valueTypeMatch {
				level.Error(logging.DefaultErrLogger).Log(
					global.LogKeyGUID, a.GUID,
					"custom_claim_name", customClaimName,
					global.LogKeyError, fmt.Sprintf("Unknown type '%s'", customClaimType),
				)

			}

			break
		}
	}
}

// getOauth2SubjectAndClaims retrieves the subject and claims for an OAuth2 client. It takes an OAuth2 client as a
// parameter and returns the subject and claims as a string and a map
func (a *Authentication) getOauth2SubjectAndClaims(oauth2Client openapi.OAuth2Client) (string, map[string]any) {
	var (
		okay    bool
		index   int
		subject string
		client  config.Oauth2Client
		claims  map[string]any
	)

	if config.LoadableConfig.Oauth2 != nil {
		claims = make(map[string]any)

		clientIDFound := false

		for index, client = range config.LoadableConfig.Oauth2.Clients {
			if client.ClientId == oauth2Client.GetClientId() {
				clientIDFound = true

				util.DebugModule(
					global.DbgAuth,
					global.LogKeyGUID, a.GUID,
					global.LogKeyMsg, fmt.Sprintf("Found client_id: %+v", client),
				)

				claims = a.processClientClaims(&client, claims)
				claims = a.applyClientClaimHandlers(&client, claims)
				a.processGroupsClaim(index, claims)

				break //exit loop once first matching client found
			}
		}

		for scopeIndex := range config.LoadableConfig.Oauth2.CustomScopes {
			a.processCustomClaims(scopeIndex, oauth2Client, claims)
		}

		if client.Subject != "" {
			var value []any

			if value, okay = a.Attributes[client.Subject]; !okay {
				level.Info(logging.DefaultLogger).Log(
					global.LogKeyGUID, a.GUID,
					global.LogKeyMsg, fmt.Sprintf(
						"Attributes did not contain requested field '%s'",
						client.Subject,
					),
					"attributes", func() string {
						var attributes []string

						for key := range a.Attributes {
							attributes = append(attributes, key)
						}

						return strings.Join(attributes, ", ")
					}(),
				)
			} else if _, okay = value[global.SliceWithOneElement].(string); okay {
				subject = value[global.SliceWithOneElement].(string)
			}
		}

		if !clientIDFound {
			level.Warn(logging.DefaultLogger).Log(global.LogKeyGUID, a.GUID, global.LogKeyMsg, "No client_id section found")
		}
	} else {
		// Default result, if no oauth2/clients definition is found
		subject = *a.AccountField
	}

	return subject, claims
}

// generateLocalChacheKey generates a string key used for caching the Authentication object in the local cache.
// The key is constructed by concatenating the UsernameOrig, Password and  Service values using a null character ('\0')
// as a separator.
func (a *Authentication) generateLocalChacheKey() string {
	return fmt.Sprintf("%s\000%s\000%s",
		a.UsernameOrig,
		a.Password,
		a.Service)
}

// getFromLocalCache retrieves the Authentication object from the local cache using the generateLocalChacheKey() as the key.
// If the object is found in the cache, it updates the fields of the current Authentication object with the cached values.
// It also sets the a.GUID field with the original value to avoid losing the GUID from the previous object.
// If the a.HTTPClientContext field is not nil, it sets it to nil and restores it after updating the Authentication object.
// It sets the a.UsedPassDBBackend field to BackendLocalCache to indicate that the cache was used.
// Finally, it sets the "local_cache_auth" key to true in the gin.Context using ctx.Set() and returns true if the object is found in the cache; otherwise, it returns false.
func (a *Authentication) getFromLocalCache(ctx *gin.Context) bool {
	if a.haveMonitoringFlag(global.MonInMemory) {
		return false
	}

	if value, found := localcache.LocalCache.Get(a.generateLocalChacheKey()); found {
		guid := *a.GUID
		restoreCtx := false

		if a.HTTPClientContext != nil {
			a.HTTPClientContext = nil
			restoreCtx = true
		}

		*a = *value.(*Authentication)

		a.GUID = &guid
		a.UsedPassDBBackend = global.BackendLocalCache

		if restoreCtx {
			a.HTTPClientContext = ctx.Copy()
		}

		ctx.Set(global.CtxLocalCacheAuthKey, true)

		return found
	} else {
		return false
	}
}

// preproccessAuthRequest preprocesses the authentication request by checking if the request is already in the local cache.
// If not found in the cache, it checks if the request is a brute force attack and updates the brute force counter.
// It then performs a post Lua action and triggers a failed authentication response.
// If a brute force attack is detected, it returns true, otherwise false.
func (a *Authentication) preproccessAuthRequest(ctx *gin.Context) (found bool, reject bool) {
	if found = a.getFromLocalCache(ctx); !found {
		stats.CacheMisses.Inc()

		if a.checkBruteForce() {
			a.updateBruteForceBucketsCounter()
			a.postLuaAction(&PassDBResult{})
			a.authFail(ctx)

			return false, true
		}
	} else {
		stats.CacheHits.Inc()
	}

	return found, false
}