add support for per user authentication methods

You can, for example, deny one or more authentication methods to one or
more users.

README.md

@@ -10,6 +10,7 @@ Full featured and highly configurable SFTP server
 - SQLite, MySQL, PostgreSQL, bbolt (key/value store in pure Go) and in memory data providers are supported.
 - Public key and password authentication. Multiple public keys per user are supported.
 - Keyboard interactive authentication. You can easily setup a customizable multi factor authentication.
+- Per user authentication methods. You can, for example, deny one or more authentication methods to one or more users.
 - Custom authentication using external programs is supported.
 - Quota support: accounts can have individual quota expressed as max total size and/or max number of files.
 - Bandwidth throttling is supported, with distinct settings for upload and download.
@@ -687,6 +688,10 @@ For each account the following properties can be configured:
 - `download_bandwidth` maximum download bandwidth as KB/s, 0 means unlimited.
 - `allowed_ip`, List of IP/Mask allowed to login. Any IP address not contained in this list cannot login. IP/Mask must be in CIDR notation as defined in RFC 4632 and RFC 4291, for example "192.0.2.0/24" or "2001:db8::/32"
 - `denied_ip`, List of IP/Mask not allowed to login. If an IP address is both allowed and denied then login will be denied
+- `denied_login_methods`, List of login methods not allowed. The following login methods are supported:
+  - `publickey`
+  - `password`
+  - `keyboard-interactive`
 - `fs_provider`, filesystem to serve via SFTP. Local filesystem and S3 Compatible Object Storage are supported
 - `s3_bucket`, required for S3 filesystem
 - `s3_region`, required for S3 filesystem. Must match the region for your bucket. You can find here the list of available [AWS regions](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-regions-availability-zones.html#concepts-available-regions). For example if your bucket is at `Frankfurt` you have to set the region to `eu-central-1`
@@ -825,7 +830,7 @@ The logs can be divided into the following categories:
     - `level` string
     - `username`, string. Can be empty if the connection is closed before an authentication attempt
     - `client_ip` string.
-    - `login_type` string. Can be `public_key`, `password` or `no_auth_tryed`
+    - `login_type` string. Can be `publickey`, `password`, `keyboard-interactive` or `no_auth_tryed`
     - `error` string. Optional error description
 
 ### Brute force protection

dataprovider/dataprovider.go

@@ -77,10 +77,12 @@ var (
 	// ValidPerms list that contains all the valid permissions for an user
 	ValidPerms = []string{PermAny, PermListItems, PermDownload, PermUpload, PermOverwrite, PermRename, PermDelete,
 		PermCreateDirs, PermCreateSymlinks, PermChmod, PermChown, PermChtimes}
-	config          Config
+	// ValidSSHLoginMethods list that contains all the valid SSH login methods
-	provider        Provider
+	ValidSSHLoginMethods = []string{SSHLoginMethodPublicKey, SSHLoginMethodPassword, SSHLoginMethodKeyboardInteractive}
-	sqlPlaceholders []string
+	config               Config
-	hashPwdPrefixes = []string{argonPwdPrefix, bcryptPwdPrefix, pbkdf2SHA1Prefix, pbkdf2SHA256Prefix,
+	provider             Provider
+	sqlPlaceholders      []string
+	hashPwdPrefixes      = []string{argonPwdPrefix, bcryptPwdPrefix, pbkdf2SHA1Prefix, pbkdf2SHA256Prefix,
 		pbkdf2SHA512Prefix, md5cryptPwdPrefix, md5cryptApr1PwdPrefix, sha512cryptPwdPrefix}
 	pbkdfPwdPrefixes       = []string{pbkdf2SHA1Prefix, pbkdf2SHA256Prefix, pbkdf2SHA512Prefix}
 	unixPwdPrefixes        = []string{md5cryptPwdPrefix, md5cryptApr1PwdPrefix, sha512cryptPwdPrefix}
@@ -510,6 +512,9 @@ func validatePermissions(user *User) error {
 		if len(perms) == 0 && dir == "/" {
 			return &ValidationError{err: fmt.Sprintf("no permissions granted for the directory: %#v", dir)}
 		}
+		if len(perms) > len(ValidPerms) {
+			return &ValidationError{err: "invalid permissions"}
+		}
 		for _, p := range perms {
 			if !utils.IsStringInSlice(p, ValidPerms) {
 				return &ValidationError{err: fmt.Sprintf("invalid permission: %#v", p)}
@@ -555,6 +560,9 @@ func validateFilters(user *User) error {
 	if len(user.Filters.DeniedIP) == 0 {
 		user.Filters.DeniedIP = []string{}
 	}
+	if len(user.Filters.DeniedLoginMethods) == 0 {
+		user.Filters.DeniedLoginMethods = []string{}
+	}
 	for _, IPMask := range user.Filters.DeniedIP {
 		_, _, err := net.ParseCIDR(IPMask)
 		if err != nil {
@@ -567,6 +575,14 @@ func validateFilters(user *User) error {
 			return &ValidationError{err: fmt.Sprintf("could not parse allowed IP/Mask %#v : %v", IPMask, err)}
 		}
 	}
+	if len(user.Filters.DeniedLoginMethods) >= len(ValidSSHLoginMethods) {
+		return &ValidationError{err: "invalid denied_login_methods"}
+	}
+	for _, loginMethod := range user.Filters.DeniedLoginMethods {
+		if !utils.IsStringInSlice(loginMethod, ValidSSHLoginMethods) {
+			return &ValidationError{err: fmt.Sprintf("invalid login method: %#v", loginMethod)}
+		}
+	}
 	return nil
 }
 

dataprovider/user.go

@@ -42,15 +42,25 @@ const (
 	PermChtimes = "chtimes"
 )
 
+// Available SSH login methods
+const (
+	SSHLoginMethodPublicKey           = "publickey"
+	SSHLoginMethodPassword            = "password"
+	SSHLoginMethodKeyboardInteractive = "keyboard-interactive"
+)
+
 // UserFilters defines additional restrictions for a user
 type UserFilters struct {
 	// only clients connecting from these IP/Mask are allowed.
 	// IP/Mask must be in CIDR notation as defined in RFC 4632 and RFC 4291
 	// for example "192.0.2.0/24" or "2001:db8::/32"
-	AllowedIP []string `json:"allowed_ip"`
+	AllowedIP []string `json:"allowed_ip,omitempty"`
 	// clients connecting from these IP/Mask are not allowed.
 	// Denied rules will be evaluated before allowed ones
-	DeniedIP []string `json:"denied_ip"`
+	DeniedIP []string `json:"denied_ip,omitempty"`
+	// these login methods are not allowed.
+	// If null or empty any available login method is allowed
+	DeniedLoginMethods []string `json:"denied_login_methods,omitempty"`
 }
 
 // Filesystem defines cloud storage filesystem details
@@ -183,11 +193,22 @@ func (u *User) HasPerms(permissions []string, path string) bool {
 	return true
 }
 
-// IsLoginAllowed return true if the login is allowed from the specified remoteAddr.
+// IsLoginMethodAllowed returns true if the specified login method is allowed for the user
+func (u *User) IsLoginMethodAllowed(loginMetod string) bool {
+	if len(u.Filters.DeniedLoginMethods) == 0 {
+		return true
+	}
+	if utils.IsStringInSlice(loginMetod, u.Filters.DeniedLoginMethods) {
+		return false
+	}
+	return true
+}
+
+// IsLoginFromAddrAllowed returns true if the login is allowed from the specified remoteAddr.
 // If AllowedIP is defined only the specified IP/Mask can login.
 // If DeniedIP is defined the specified IP/Mask cannot login.
 // If an IP is both allowed and denied then login will be denied
-func (u *User) IsLoginAllowed(remoteAddr string) bool {
+func (u *User) IsLoginFromAddrAllowed(remoteAddr string) bool {
 	if len(u.Filters.AllowedIP) == 0 && len(u.Filters.DeniedIP) == 0 {
 		return true
 	}
@@ -407,6 +428,8 @@ func (u *User) getACopy() User {
 	copy(filters.AllowedIP, u.Filters.AllowedIP)
 	filters.DeniedIP = make([]string, len(u.Filters.DeniedIP))
 	copy(filters.DeniedIP, u.Filters.DeniedIP)
+	filters.DeniedLoginMethods = make([]string, len(u.Filters.DeniedLoginMethods))
+	copy(filters.DeniedLoginMethods, u.Filters.DeniedLoginMethods)
 	fsConfig := Filesystem{
 		Provider: u.FsConfig.Provider,
 		S3Config: vfs.S3FsConfig{

httpd/api_utils.go

@@ -503,6 +503,9 @@ func compareUserFilters(expected *dataprovider.User, actual *dataprovider.User)
 	if len(expected.Filters.DeniedIP) != len(actual.Filters.DeniedIP) {
 		return errors.New("DeniedIP mismatch")
 	}
+	if len(expected.Filters.DeniedLoginMethods) != len(actual.Filters.DeniedLoginMethods) {
+		return errors.New("Denied login methods mismatch")
+	}
 	for _, IPMask := range expected.Filters.AllowedIP {
 		if !utils.IsStringInSlice(IPMask, actual.Filters.AllowedIP) {
 			return errors.New("AllowedIP contents mismatch")
@@ -513,6 +516,11 @@ func compareUserFilters(expected *dataprovider.User, actual *dataprovider.User)
 			return errors.New("DeniedIP contents mismatch")
 		}
 	}
+	for _, method := range expected.Filters.DeniedLoginMethods {
+		if !utils.IsStringInSlice(method, actual.Filters.DeniedLoginMethods) {
+			return errors.New("Denied login methods contents mismatch")
+		}
+	}
 	return nil
 }
 

httpd/httpd_test.go

@@ -312,6 +312,18 @@ func TestAddUserInvalidFilters(t *testing.T) {
 	if err != nil {
 		t.Errorf("unexpected error adding user with invalid filters: %v", err)
 	}
+	u.Filters.DeniedIP = []string{}
+	u.Filters.DeniedLoginMethods = []string{"invalid"}
+	_, _, err = httpd.AddUser(u, http.StatusBadRequest)
+	if err != nil {
+		t.Errorf("unexpected error adding user with invalid filters: %v", err)
+	}
+	u.Filters.DeniedLoginMethods = []string{dataprovider.SSHLoginMethodKeyboardInteractive,
+		dataprovider.SSHLoginMethodPassword, dataprovider.SSHLoginMethodPublicKey}
+	_, _, err = httpd.AddUser(u, http.StatusBadRequest)
+	if err != nil {
+		t.Errorf("unexpected error adding user with invalid filters: %v", err)
+	}
 }
 
 func TestAddUserInvalidFsConfig(t *testing.T) {
@@ -409,6 +421,7 @@ func TestUpdateUser(t *testing.T) {
 	user.Permissions["/subdir"] = []string{dataprovider.PermListItems, dataprovider.PermUpload}
 	user.Filters.AllowedIP = []string{"192.168.1.0/24", "192.168.2.0/24"}
 	user.Filters.DeniedIP = []string{"192.168.3.0/24", "192.168.4.0/24"}
+	user.Filters.DeniedLoginMethods = []string{dataprovider.SSHLoginMethodPassword}
 	user.UploadBandwidth = 1024
 	user.DownloadBandwidth = 512
 	user, _, err = httpd.UpdateUser(user, http.StatusOK)
@@ -893,7 +906,7 @@ func TestDumpdata(t *testing.T) {
 	os.RemoveAll(credentialsPath)
 	err = dataprovider.Initialize(providerConf, configDir)
 	if err != nil {
-		t.Errorf("error initializing data provider")
+		t.Errorf("error initializing data provider: %v", err)
 	}
 	httpd.SetDataProvider(dataprovider.GetProvider())
 	sftpd.SetDataProvider(dataprovider.GetProvider())
@@ -1720,6 +1733,7 @@ func TestWebUserUpdateMock(t *testing.T) {
 	form.Set("expiration_date", "2020-01-01 00:00:00")
 	form.Set("allowed_ip", " 192.168.1.3/32, 192.168.2.0/24 ")
 	form.Set("denied_ip", " 10.0.0.2/32 ")
+	form.Set("ssh_login_methods", dataprovider.SSHLoginMethodKeyboardInteractive)
 	b, contentType, _ := getMultipartFormData(form, "", "")
 	req, _ = http.NewRequest(http.MethodPost, webUserPath+"/"+strconv.FormatInt(user.ID, 10), &b)
 	req.Header.Set("Content-Type", contentType)
@@ -1765,6 +1779,9 @@ func TestWebUserUpdateMock(t *testing.T) {
 	if !utils.IsStringInSlice("10.0.0.2/32", updateUser.Filters.DeniedIP) {
 		t.Errorf("Denied IP/Mask does not match: %v", updateUser.Filters.DeniedIP)
 	}
+	if !utils.IsStringInSlice(dataprovider.SSHLoginMethodKeyboardInteractive, updateUser.Filters.DeniedLoginMethods) {
+		t.Errorf("Denied login methods does not match: %v", updateUser.Filters.DeniedLoginMethods)
+	}
 	req, _ = http.NewRequest(http.MethodDelete, userPath+"/"+strconv.FormatInt(user.ID, 10), nil)
 	rr = executeRequest(req)
 	checkResponseCode(t, http.StatusOK, rr.Code)

httpd/internal_test.go

@@ -59,12 +59,6 @@ func TestCheckUser(t *testing.T) {
 		t.Errorf("actual password must be nil")
 	}
 	actual.Password = ""
-	actual.PublicKeys = []string{"pub key"}
-	err = checkUser(expected, actual)
-	if err == nil {
-		t.Errorf("actual public key must be nil")
-	}
-	actual.PublicKeys = []string{}
 	err = checkUser(expected, actual)
 	if err == nil {
 		t.Errorf("actual ID must be > 0")
@@ -104,9 +98,21 @@ func TestCheckUser(t *testing.T) {
 	}
 	expected.Permissions = make(map[string][]string)
 	actual.Permissions = make(map[string][]string)
+	actual.FsConfig.Provider = 1
+	err = checkUser(expected, actual)
+	if err == nil {
+		t.Errorf("Fs providers are not equal")
+	}
+}
+
+func TestCompareUserFilters(t *testing.T) {
+	expected := &dataprovider.User{}
+	actual := &dataprovider.User{}
+	actual.ID = 1
+	expected.ID = 1
 	expected.Filters.AllowedIP = []string{}
 	actual.Filters.AllowedIP = []string{"192.168.1.2/32"}
-	err = checkUser(expected, actual)
+	err := checkUser(expected, actual)
 	if err == nil {
 		t.Errorf("AllowedIP are not equal")
 	}
@@ -130,10 +136,16 @@ func TestCheckUser(t *testing.T) {
 	}
 	expected.Filters.DeniedIP = []string{}
 	actual.Filters.DeniedIP = []string{}
-	actual.FsConfig.Provider = 1
+	expected.Filters.DeniedLoginMethods = []string{}
+	actual.Filters.DeniedLoginMethods = []string{dataprovider.SSHLoginMethodPublicKey}
 	err = checkUser(expected, actual)
 	if err == nil {
-		t.Errorf("Fs providers are not equal")
+		t.Errorf("Denied login methods are not equal")
+	}
+	expected.Filters.DeniedLoginMethods = []string{dataprovider.SSHLoginMethodPassword}
+	err = checkUser(expected, actual)
+	if err == nil {
+		t.Errorf("Denied login methods contents are not equal")
 	}
 }
 

httpd/schema/openapi.yaml

@@ -2,7 +2,7 @@ openapi: 3.0.1
 info:
   title: SFTPGo
   description: 'SFTPGo REST API'
-  version: 1.8.0
+  version: 1.8.1
 
 servers:
 - url: /api/v1
@@ -927,6 +927,12 @@ components:
         minItems: 1
       minProperties: 1
       description: hash map with directory as key and an array of permissions as value. Directories must be absolute paths, permissions for root directory ("/") are required
+    LoginMethods:
+      type: string
+      enum:
+        - 'publickey'
+        - 'password'
+        - 'keyboard-interactive'
     UserFilters:
       type: object
       properties:
@@ -944,6 +950,12 @@ components:
           nullable: true
           description: clients connecting from these IP/Mask are not allowed. Denied rules are evaluated before allowed ones
           example: [ "172.16.0.0/16" ]
+        denied_login_methods:
+          type: array
+          items:
+            $ref: '#/components/schemas/LoginMethods'
+          nullable: true
+          description: if null or empty any available login method is allowed
       description: Additional restrictions
     S3Config:
       type: object
@@ -973,8 +985,6 @@ components:
       required:
         - bucket
         - region
-        - access_key
-        - access_secret
       nullable: true
       description: S3 Compatible Object Storage configuration details
     GCSConfig:

httpd/web.go

@@ -64,12 +64,13 @@ type connectionsPage struct {
 
 type userPage struct {
 	basePage
-	IsAdd        bool
+	IsAdd                bool
-	User         dataprovider.User
+	User                 dataprovider.User
-	RootPerms    []string
+	RootPerms            []string
-	Error        string
+	Error                string
-	ValidPerms   []string
+	ValidPerms           []string
-	RootDirPerms []string
+	ValidSSHLoginMethods []string
+	RootDirPerms         []string
 }
 
 type messagePage struct {
@@ -161,24 +162,26 @@ func renderNotFoundPage(w http.ResponseWriter, err error) {
 
 func renderAddUserPage(w http.ResponseWriter, user dataprovider.User, error string) {
 	data := userPage{
-		basePage:     getBasePageData("Add a new user", webUserPath),
+		basePage:             getBasePageData("Add a new user", webUserPath),
-		IsAdd:        true,
+		IsAdd:                true,
-		Error:        error,
+		Error:                error,
-		User:         user,
+		User:                 user,
-		ValidPerms:   dataprovider.ValidPerms,
+		ValidPerms:           dataprovider.ValidPerms,
-		RootDirPerms: user.GetPermissionsForPath("/"),
+		ValidSSHLoginMethods: dataprovider.ValidSSHLoginMethods,
+		RootDirPerms:         user.GetPermissionsForPath("/"),
 	}
 	renderTemplate(w, templateUser, data)
 }
 
 func renderUpdateUserPage(w http.ResponseWriter, user dataprovider.User, error string) {
 	data := userPage{
-		basePage:     getBasePageData("Update user", fmt.Sprintf("%v/%v", webUserPath, user.ID)),
+		basePage:             getBasePageData("Update user", fmt.Sprintf("%v/%v", webUserPath, user.ID)),
-		IsAdd:        false,
+		IsAdd:                false,
-		Error:        error,
+		Error:                error,
-		User:         user,
+		User:                 user,
-		ValidPerms:   dataprovider.ValidPerms,
+		ValidPerms:           dataprovider.ValidPerms,
-		RootDirPerms: user.GetPermissionsForPath("/"),
+		ValidSSHLoginMethods: dataprovider.ValidSSHLoginMethods,
+		RootDirPerms:         user.GetPermissionsForPath("/"),
 	}
 	renderTemplate(w, templateUser, data)
 }
@@ -224,6 +227,7 @@ func getFiltersFromUserPostFields(r *http.Request) dataprovider.UserFilters {
 	var filters dataprovider.UserFilters
 	filters.AllowedIP = getSliceFromDelimitedValues(r.Form.Get("allowed_ip"), ",")
 	filters.DeniedIP = getSliceFromDelimitedValues(r.Form.Get("denied_ip"), ",")
+	filters.DeniedLoginMethods = r.Form["ssh_login_methods"]
 	return filters
 }
 

metrics/metrics.go

@@ -494,7 +494,7 @@ func UpdateDataProviderAvailability(err error) {
 func AddLoginAttempt(authMethod string) {
 	totalLoginAttempts.Inc()
 	switch authMethod {
-	case "public_key":
+	case "publickey":
 		totalKeyLoginAttempts.Inc()
 	case "keyboard-interactive":
 		totalInteractiveLoginAttempts.Inc()
@@ -508,7 +508,7 @@ func AddLoginResult(authMethod string, err error) {
 	if err == nil {
 		totalLoginOK.Inc()
 		switch authMethod {
-		case "public_key":
+		case "publickey":
 			totalKeyLoginOK.Inc()
 		case "keyboard-interactive":
 			totalInteractiveLoginOK.Inc()
@@ -518,7 +518,7 @@ func AddLoginResult(authMethod string, err error) {
 	} else {
 		totalLoginFailed.Inc()
 		switch authMethod {
-		case "public_key":
+		case "publickey":
 			totalKeyLoginFailed.Inc()
 		case "keyboard-interactive":
 			totalInteractiveLoginFailed.Inc()

scripts/README.md

@@ -44,7 +44,7 @@ Let's see a sample usage for each REST API.
 Command:
 
 ```
-python sftpgo_api_cli.py add-user test_username --password "test_pwd" --home-dir="/tmp/test_home_dir" --uid 33 --gid 1000 --max-sessions 2 --quota-size 0 --quota-files 3 --permissions "list" "download" "upload" "delete" "rename" "create_dirs" "overwrite" --subdirs-permissions "/dir1:list,download" "/dir2:*" --upload-bandwidth 100 --download-bandwidth 60 --status 0 --expiration-date 2019-01-01 --allowed-ip "192.168.1.1/32" --fs S3 --s3-bucket test --s3-region eu-west-1 --s3-access-key accesskey --s3-access-secret secret --s3-endpoint "http://127.0.0.1:9000" --s3-storage-class Standard --s3-key-prefix "vfolder/"
+python sftpgo_api_cli.py add-user test_username --password "test_pwd" --home-dir="/tmp/test_home_dir" --uid 33 --gid 1000 --max-sessions 2 --quota-size 0 --quota-files 3 --permissions "list" "download" "upload" "delete" "rename" "create_dirs" "overwrite" --subdirs-permissions "/dir1:list,download" "/dir2:*" --upload-bandwidth 100 --download-bandwidth 60 --status 0 --expiration-date 2019-01-01 --allowed-ip "192.168.1.1/32" --fs S3 --s3-bucket test --s3-region eu-west-1 --s3-access-key accesskey --s3-access-secret secret --s3-endpoint "http://127.0.0.1:9000" --s3-storage-class Standard --s3-key-prefix "vfolder/" --denied-login-methods "password" "keyboard-interactive"
 ```
 
 Output:
@@ -70,7 +70,10 @@ Output:
     "allowed_ip": [
       "192.168.1.1/32"
     ],
-    "denied_ip": []
+    "denied_login_methods": [
+      "password",
+      "keyboard-interactive"
+    ]
   },
   "gid": 1000,
   "home_dir": "/tmp/test_home_dir",
@@ -112,7 +115,7 @@ Output:
 Command:
 
 ```
-python sftpgo_api_cli.py update-user 9576 test_username --password "test_pwd" --home-dir="/tmp/test_home_dir" --uid 0 --gid 33 --max-sessions 3 --quota-size 0 --quota-files 4 --permissions "*" --subdirs-permissions "/dir1:list,download,create_symlinks" --upload-bandwidth 90 --download-bandwidth 80 --status 1 --expiration-date "" --allowed-ip "" --denied-ip "192.168.1.0/24" --fs local
+python sftpgo_api_cli.py update-user 9576 test_username --password "test_pwd" --home-dir="/tmp/test_home_dir" --uid 0 --gid 33 --max-sessions 3 --quota-size 0 --quota-files 4 --permissions "*" --subdirs-permissions "/dir1:list,download,create_symlinks" --upload-bandwidth 90 --download-bandwidth 80 --status 1 --expiration-date "" --allowed-ip "" --denied-ip "192.168.1.0/24" --denied-login-methods "" --fs local
 ```
 
 Output:
@@ -145,7 +148,6 @@ Output:
     "s3config": {}
   },
   "filters": {
-    "allowed_ip": [],
     "denied_ip": [
       "192.168.1.0/24"
     ]
@@ -198,7 +200,6 @@ Output:
       "s3config": {}
     },
     "filters": {
-      "allowed_ip": [],
       "denied_ip": [
         "192.168.1.0/24"
       ]

scripts/sftpgo_api_cli.py

@@ -76,7 +76,7 @@ class SFTPGoApiRequests:
 					status=1, expiration_date=0, allowed_ip=[], denied_ip=[], fs_provider='local', s3_bucket='',
 					s3_region='', s3_access_key='', s3_access_secret='', s3_endpoint='', s3_storage_class='',
 					s3_key_prefix='', gcs_bucket='', gcs_key_prefix='', gcs_storage_class='', gcs_credentials_file='',
-					gcs_automatic_credentials='automatic'):
+					gcs_automatic_credentials='automatic', denied_login_methods=[]):
 		user = {'id':user_id, 'username':username, 'uid':uid, 'gid':gid,
 			'max_sessions':max_sessions, 'quota_size':quota_size, 'quota_files':quota_files,
 			'upload_bandwidth':upload_bandwidth, 'download_bandwidth':download_bandwidth,
@@ -92,8 +92,8 @@ class SFTPGoApiRequests:
 			user.update({'home_dir':home_dir})
 		if permissions:
 			user.update({'permissions':permissions})
-		if allowed_ip or denied_ip:
+		if allowed_ip or denied_ip or denied_login_methods:
-			user.update({'filters':self.buildFilters(allowed_ip, denied_ip)})
+			user.update({'filters':self.buildFilters(allowed_ip, denied_ip, denied_login_methods)})
 		user.update({'filesystem':self.buildFsConfig(fs_provider, s3_bucket, s3_region, s3_access_key, s3_access_secret,
 													s3_endpoint, s3_storage_class, s3_key_prefix, gcs_bucket,
 													gcs_key_prefix, gcs_storage_class, gcs_credentials_file,
@@ -117,7 +117,7 @@ class SFTPGoApiRequests:
 					permissions.update({directory:values})
 		return permissions
 
-	def buildFilters(self, allowed_ip, denied_ip):
+	def buildFilters(self, allowed_ip, denied_ip, denied_login_methods):
 		filters = {}
 		if allowed_ip:
 			if len(allowed_ip) == 1 and not allowed_ip[0]:
@@ -129,6 +129,11 @@ class SFTPGoApiRequests:
 				filters.update({'denied_ip':[]})
 			else:
 				filters.update({'denied_ip':denied_ip})
+		if denied_login_methods:
+			if len(denied_login_methods) == 1 and not denied_login_methods[0]:
+				filters.update({'denied_login_methods':[]})
+			else:
+				filters.update({'denied_login_methods':denied_login_methods})
 		return filters
 
 	def buildFsConfig(self, fs_provider, s3_bucket, s3_region, s3_access_key, s3_access_secret, s3_endpoint,
@@ -166,12 +171,13 @@ class SFTPGoApiRequests:
 			quota_files=0, perms=[], upload_bandwidth=0, download_bandwidth=0, status=1, expiration_date=0,
 			subdirs_permissions=[], allowed_ip=[], denied_ip=[], fs_provider='local', s3_bucket='', s3_region='',
 			s3_access_key='', s3_access_secret='', s3_endpoint='', s3_storage_class='', s3_key_prefix='', gcs_bucket='',
-			gcs_key_prefix='', gcs_storage_class='', gcs_credentials_file='', gcs_automatic_credentials='automatic'):
+			gcs_key_prefix='', gcs_storage_class='', gcs_credentials_file='', gcs_automatic_credentials='automatic',
+			denied_login_methods=[]):
 		u = self.buildUserObject(0, username, password, public_keys, home_dir, uid, gid, max_sessions,
 			quota_size, quota_files, self.buildPermissions(perms, subdirs_permissions), upload_bandwidth, download_bandwidth,
 			status, expiration_date, allowed_ip, denied_ip, fs_provider, s3_bucket, s3_region, s3_access_key,
 			s3_access_secret, s3_endpoint, s3_storage_class, s3_key_prefix, gcs_bucket, gcs_key_prefix, gcs_storage_class,
-			gcs_credentials_file, gcs_automatic_credentials)
+			gcs_credentials_file, gcs_automatic_credentials, denied_login_methods)
 		r = requests.post(self.userPath, json=u, auth=self.auth, verify=self.verify)
 		self.printResponse(r)
 
@@ -180,12 +186,12 @@ class SFTPGoApiRequests:
 				expiration_date=0, subdirs_permissions=[], allowed_ip=[], denied_ip=[], fs_provider='local',
 				s3_bucket='', s3_region='', s3_access_key='', s3_access_secret='', s3_endpoint='', s3_storage_class='',
 				s3_key_prefix='', gcs_bucket='', gcs_key_prefix='', gcs_storage_class='', gcs_credentials_file='',
-				gcs_automatic_credentials='automatic'):
+				gcs_automatic_credentials='automatic', denied_login_methods=[]):
 		u = self.buildUserObject(user_id, username, password, public_keys, home_dir, uid, gid, max_sessions,
 			quota_size, quota_files, self.buildPermissions(perms, subdirs_permissions), upload_bandwidth, download_bandwidth,
 			status, expiration_date, allowed_ip, denied_ip, fs_provider, s3_bucket, s3_region, s3_access_key,
 			s3_access_secret, s3_endpoint, s3_storage_class, s3_key_prefix, gcs_bucket, gcs_key_prefix, gcs_storage_class,
-			gcs_credentials_file, gcs_automatic_credentials)
+			gcs_credentials_file, gcs_automatic_credentials, denied_login_methods)
 		r = requests.put(urlparse.urljoin(self.userPath, 'user/' + str(user_id)), json=u, auth=self.auth, verify=self.verify)
 		self.printResponse(r)
 
@@ -426,6 +432,8 @@ def addCommonUserArguments(parser):
 					choices=['*', 'list', 'download', 'upload', 'overwrite', 'delete', 'rename', 'create_dirs',
 							'create_symlinks', 'chmod', 'chown', 'chtimes'], help='Permissions for the root directory '
 							+'(/). Default: %(default)s')
+	parser.add_argument('-L', '--denied-login-methods', type=str, nargs='+', default=[],
+					choices=['', 'publickey', 'password', 'keyboard-interactive'], help='Default: %(default)s')
 	parser.add_argument('--subdirs-permissions', type=str, nargs='*', default=[], help='Permissions for subdirs. '
 					+'For example: "/somedir:list,download" "/otherdir/subdir:*" Default: %(default)s')
 	parser.add_argument('-U', '--upload-bandwidth', type=int, default=0,
@@ -569,7 +577,8 @@ if __name__ == '__main__':
 				args.status, getDatetimeAsMillisSinceEpoch(args.expiration_date), args.subdirs_permissions, args.allowed_ip,
 				args.denied_ip, args.fs, args.s3_bucket, args.s3_region, args.s3_access_key, args.s3_access_secret,
 				args.s3_endpoint, args.s3_storage_class, args.s3_key_prefix, args.gcs_bucket, args.gcs_key_prefix,
-				args.gcs_storage_class, args.gcs_credentials_file, args.gcs_automatic_credentials)
+				args.gcs_storage_class, args.gcs_credentials_file, args.gcs_automatic_credentials,
+				args.denied_login_methods)
 	elif args.command == 'update-user':
 		api.updateUser(args.id, args.username, args.password, args.public_keys, args.home_dir, args.uid, args.gid,
 					args.max_sessions, args.quota_size, args.quota_files, args.permissions, args.upload_bandwidth,
@@ -577,7 +586,7 @@ if __name__ == '__main__':
 					args.subdirs_permissions, args.allowed_ip, args.denied_ip, args.fs, args.s3_bucket, args.s3_region,
 					args.s3_access_key, args.s3_access_secret, args.s3_endpoint, args.s3_storage_class,
 					args.s3_key_prefix, args.gcs_bucket, args.gcs_key_prefix, args.gcs_storage_class,
-					args.gcs_credentials_file, args.gcs_automatic_credentials)
+					args.gcs_credentials_file, args.gcs_automatic_credentials, args.denied_login_methods)
 	elif args.command == 'delete-user':
 		api.deleteUser(args.id)
 	elif args.command == 'get-users':

sftpd/internal_test.go

@@ -438,7 +438,7 @@ func TestUploadFiles(t *testing.T) {
 func TestWithInvalidHome(t *testing.T) {
 	u := dataprovider.User{}
 	u.HomeDir = "home_rel_path"
-	_, err := loginUser(u, "password", "")
+	_, err := loginUser(u, dataprovider.SSHLoginMethodPassword, "", "")
 	if err == nil {
 		t.Errorf("login a user with an invalid home_dir must fail")
 	}

sftpd/server.go

@@ -292,7 +292,7 @@ func (c Configuration) AcceptInboundConnection(conn net.Conn, config *ssh.Server
 	// Unmarshal cannot fails here and even if it fails we'll have a user with no permissions
 	json.Unmarshal([]byte(sconn.Permissions.Extensions["user"]), &user)
 
-	loginType := sconn.Permissions.Extensions["login_type"]
+	loginType := sconn.Permissions.Extensions["login_method"]
 	connectionID := hex.EncodeToString(sconn.SessionID())
 
 	fs, err := user.GetFilesystem(connectionID)
@@ -391,7 +391,7 @@ func (c Configuration) createHandler(connection Connection) sftp.Handlers {
 	}
 }
 
-func loginUser(user dataprovider.User, loginType string, remoteAddr string) (*ssh.Permissions, error) {
+func loginUser(user dataprovider.User, loginMethod, remoteAddr, publicKey string) (*ssh.Permissions, error) {
 	if !filepath.IsAbs(user.HomeDir) {
 		logger.Warn(logSender, "", "user %#v has an invalid home dir: %#v. Home dir must be an absolute path, login not allowed",
 			user.Username, user.HomeDir)
@@ -405,9 +405,13 @@ func loginUser(user dataprovider.User, loginType string, remoteAddr string) (*ss
 			return nil, fmt.Errorf("too many open sessions: %v", activeSessions)
 		}
 	}
-	if !user.IsLoginAllowed(remoteAddr) {
+	if !user.IsLoginMethodAllowed(loginMethod) {
+		logger.Debug(logSender, "", "cannot login user %#v, login method %#v is not allowed", user.Username, loginMethod)
+		return nil, fmt.Errorf("Login method %#v is not allowed for user %#v", loginMethod, user.Username)
+	}
+	if !user.IsLoginFromAddrAllowed(remoteAddr) {
 		logger.Debug(logSender, "", "cannot login user %#v, remote address is not allowed: %v", user.Username, remoteAddr)
-		return nil, fmt.Errorf("Login is not allowed from this address: %v", remoteAddr)
+		return nil, fmt.Errorf("Login for user %#v is not allowed from this address: %v", user.Username, remoteAddr)
 	}
 
 	json, err := json.Marshal(user)
@@ -415,10 +419,13 @@ func loginUser(user dataprovider.User, loginType string, remoteAddr string) (*ss
 		logger.Warn(logSender, "", "error serializing user info: %v, authentication rejected", err)
 		return nil, err
 	}
+	if len(publicKey) > 0 {
+		loginMethod = fmt.Sprintf("%v: %v", loginMethod, publicKey)
+	}
 	p := &ssh.Permissions{}
 	p.Extensions = make(map[string]string)
 	p.Extensions["user"] = string(json)
-	p.Extensions["login_type"] = loginType
+	p.Extensions["login_method"] = loginMethod
 	return p, nil
 }
 
@@ -472,11 +479,12 @@ func (c Configuration) validatePublicKeyCredentials(conn ssh.ConnMetadata, pubKe
 	var keyID string
 	var sshPerm *ssh.Permissions
 
-	method := "public_key"
+	method := dataprovider.SSHLoginMethodPublicKey
 	metrics.AddLoginAttempt(method)
 	if user, keyID, err = dataprovider.CheckUserAndPubKey(dataProvider, conn.User(), pubKey); err == nil {
-		sshPerm, err = loginUser(user, fmt.Sprintf("%v:%v", method, keyID), conn.RemoteAddr().String())
+		sshPerm, err = loginUser(user, method, conn.RemoteAddr().String(), keyID)
-	} else {
+	}
+	if err != nil {
 		logger.ConnectionFailedLog(conn.User(), utils.GetIPFromRemoteAddress(conn.RemoteAddr().String()), method, err.Error())
 	}
 	metrics.AddLoginResult(method, err)
@@ -488,11 +496,12 @@ func (c Configuration) validatePasswordCredentials(conn ssh.ConnMetadata, pass [
 	var user dataprovider.User
 	var sshPerm *ssh.Permissions
 
-	method := "password"
+	method := dataprovider.SSHLoginMethodPassword
 	metrics.AddLoginAttempt(method)
 	if user, err = dataprovider.CheckUserAndPass(dataProvider, conn.User(), string(pass)); err == nil {
-		sshPerm, err = loginUser(user, method, conn.RemoteAddr().String())
+		sshPerm, err = loginUser(user, method, conn.RemoteAddr().String(), "")
-	} else {
+	}
+	if err != nil {
 		logger.ConnectionFailedLog(conn.User(), utils.GetIPFromRemoteAddress(conn.RemoteAddr().String()), method, err.Error())
 	}
 	metrics.AddLoginResult(method, err)
@@ -504,11 +513,12 @@ func (c Configuration) validateKeyboardInteractiveCredentials(conn ssh.ConnMetad
 	var user dataprovider.User
 	var sshPerm *ssh.Permissions
 
-	method := "keyboard-interactive"
+	method := dataprovider.SSHLoginMethodKeyboardInteractive
 	metrics.AddLoginAttempt(method)
 	if user, err = dataprovider.CheckKeyboardInteractiveAuth(dataProvider, conn.User(), c.KeyboardInteractiveProgram, client); err == nil {
-		sshPerm, err = loginUser(user, method, conn.RemoteAddr().String())
+		sshPerm, err = loginUser(user, method, conn.RemoteAddr().String(), "")
-	} else {
+	}
+	if err != nil {
 		logger.ConnectionFailedLog(conn.User(), utils.GetIPFromRemoteAddress(conn.RemoteAddr().String()), method, err.Error())
 	}
 	metrics.AddLoginResult(method, err)

sftpd/sftpd_test.go

@@ -1072,6 +1072,55 @@ func TestLoginInvalidFs(t *testing.T) {
 	os.RemoveAll(user.GetHomeDir())
 }
 
+func TestDeniedLoginMethods(t *testing.T) {
+	u := getTestUser(true)
+	u.Filters.DeniedLoginMethods = []string{dataprovider.SSHLoginMethodPublicKey, dataprovider.SSHLoginMethodPassword}
+	user, _, err := httpd.AddUser(u, http.StatusOK)
+	if err != nil {
+		t.Errorf("unable to add user: %v", err)
+	}
+	_, err = getSftpClient(user, true)
+	if err == nil {
+		t.Error("public key login is disabled, authentication must fail")
+	}
+	user.Filters.DeniedLoginMethods = []string{dataprovider.SSHLoginMethodKeyboardInteractive, dataprovider.SSHLoginMethodPassword}
+	user, _, err = httpd.UpdateUser(user, http.StatusOK)
+	if err != nil {
+		t.Errorf("unable to update user: %v", err)
+	}
+	client, err := getSftpClient(user, true)
+	if err != nil {
+		t.Errorf("unable to create sftp client: %v", err)
+	} else {
+		client.Close()
+	}
+	user.Password = defaultPassword
+	user, _, err = httpd.UpdateUser(user, http.StatusOK)
+	if err != nil {
+		t.Errorf("unable to update user: %v", err)
+	}
+	_, err = getSftpClient(user, false)
+	if err == nil {
+		t.Error("password login is disabled, authentication must fail")
+	}
+	user.Filters.DeniedLoginMethods = []string{dataprovider.SSHLoginMethodKeyboardInteractive, dataprovider.SSHLoginMethodPublicKey}
+	user, _, err = httpd.UpdateUser(user, http.StatusOK)
+	if err != nil {
+		t.Errorf("unable to update user: %v", err)
+	}
+	client, err = getSftpClient(user, false)
+	if err != nil {
+		t.Errorf("unable to create sftp client: %v", err)
+	} else {
+		client.Close()
+	}
+	_, err = httpd.RemoveUser(user, http.StatusOK)
+	if err != nil {
+		t.Errorf("unable to remove user: %v", err)
+	}
+	os.RemoveAll(user.GetHomeDir())
+}
+
 func TestLoginWithIPFilters(t *testing.T) {
 	usePubKey := true
 	u := getTestUser(usePubKey)
@@ -3264,53 +3313,53 @@ func TestUserEmptySubDirPerms(t *testing.T) {
 func TestUserFiltersIPMaskConditions(t *testing.T) {
 	user := getTestUser(true)
 	// with no filter login must be allowed even if the remoteIP is invalid
-	if !user.IsLoginAllowed("192.168.1.5") {
+	if !user.IsLoginFromAddrAllowed("192.168.1.5") {
 		t.Error("unexpected login denied")
 	}
-	if !user.IsLoginAllowed("invalid") {
+	if !user.IsLoginFromAddrAllowed("invalid") {
 		t.Error("unexpected login denied")
 	}
 	user.Filters.DeniedIP = append(user.Filters.DeniedIP, "192.168.1.0/24")
-	if user.IsLoginAllowed("192.168.1.5") {
+	if user.IsLoginFromAddrAllowed("192.168.1.5") {
 		t.Error("unexpected login allowed")
 	}
-	if !user.IsLoginAllowed("192.168.2.6") {
+	if !user.IsLoginFromAddrAllowed("192.168.2.6") {
 		t.Error("unexpected login denied")
 	}
 	user.Filters.AllowedIP = append(user.Filters.AllowedIP, "192.168.1.5/32")
 	// if the same ip/mask is both denied and allowed then login must be denied
-	if user.IsLoginAllowed("192.168.1.5") {
+	if user.IsLoginFromAddrAllowed("192.168.1.5") {
 		t.Error("unexpected login allowed")
 	}
-	if user.IsLoginAllowed("192.168.3.6") {
+	if user.IsLoginFromAddrAllowed("192.168.3.6") {
 		t.Error("unexpected login allowed")
 	}
 	user.Filters.DeniedIP = []string{}
-	if !user.IsLoginAllowed("192.168.1.5") {
+	if !user.IsLoginFromAddrAllowed("192.168.1.5") {
 		t.Error("unexpected login denied")
 	}
-	if user.IsLoginAllowed("192.168.1.6") {
+	if user.IsLoginFromAddrAllowed("192.168.1.6") {
 		t.Error("unexpected login allowed")
 	}
 	user.Filters.DeniedIP = []string{"192.168.0.0/16", "172.16.0.0/16"}
 	user.Filters.AllowedIP = []string{}
-	if user.IsLoginAllowed("192.168.5.255") {
+	if user.IsLoginFromAddrAllowed("192.168.5.255") {
 		t.Error("unexpected login allowed")
 	}
-	if user.IsLoginAllowed("172.16.1.2") {
+	if user.IsLoginFromAddrAllowed("172.16.1.2") {
 		t.Error("unexpected login allowed")
 	}
-	if !user.IsLoginAllowed("172.18.2.1") {
+	if !user.IsLoginFromAddrAllowed("172.18.2.1") {
 		t.Error("unexpected login denied")
 	}
 	user.Filters.AllowedIP = []string{"10.4.4.0/24"}
-	if user.IsLoginAllowed("10.5.4.2") {
+	if user.IsLoginFromAddrAllowed("10.5.4.2") {
 		t.Error("unexpected login allowed")
 	}
-	if !user.IsLoginAllowed("10.4.4.2") {
+	if !user.IsLoginFromAddrAllowed("10.4.4.2") {
 		t.Error("unexpected login denied")
 	}
-	if !user.IsLoginAllowed("invalid") {
+	if !user.IsLoginFromAddrAllowed("invalid") {
 		t.Error("unexpected login denied")
 	}
 }

templates/user.html

@@ -70,6 +70,19 @@
         </div>
     </div>
 
+    <div class="form-group row">
+        <label for="idLoginMethods" class="col-sm-2 col-form-label">Denied login methods</label>
+        <div class="col-sm-10">
+            <select class="form-control" id="idLoginMethods" name="ssh_login_methods" multiple>
+                {{range $method := .ValidSSHLoginMethods}}
+                <option value="{{$method}}"
+                    {{range $m := $.User.Filters.DeniedLoginMethods }}{{if eq $m $method}}selected{{end}}{{end}}>{{$method}}
+                </option>
+                {{end}}
+            </select>
+        </div>
+    </div>
+
     <div class="form-group row">
         <label for="idPermissions" class="col-sm-2 col-form-label">Permissions</label>
         <div class="col-sm-10">