Add support for hashed passwords (#876)

* Add support for hashed passwords in ftpserver.json

* Add option for config file to automatically hash plain-text passwords

* Prevent hashing of anonymous user's plain-text password

* Fix issue where ftpserver.json got truncated without being saved

* Improve the way config is saved after hashing passwords

* Change in-memory config when hashing plain-text passwords

Author: wanieru

config-schema.json

@@ -51,6 +51,15 @@
                 200
             ]
         },
+        "hash_plaintext_passwords": {
+            "type": "boolean",
+            "default": false,
+            "title": "Overwrite plain-text passwords with hashed equivalents",
+            "examples": [
+                true,
+                false
+            ]
+        },
         "passive_transfer_port_range": {
             "type": "object",
             "default": {},
@@ -183,22 +192,15 @@
                         "type": "string",
                         "title": "The FTP user",
                         "examples": [
-                            "test",
-                            "dropbox",
-                            "gdrive",
-                            "s3",
-                            "sftp"
+                            "username"
                         ]
                     },
                     "pass": {
                         "type": "string",
                         "title": "The FTP password",
                         "examples": [
-                            "test",
-                            "dropbox",
-                            "gdrive",
-                            "s3",
-                            "sftp"
+                            "plaintext-password",
+                            "$2a$10$jG7tuqIlcUDMl1m1Ytj1TunU7pk.ko8lj3nOGzZvkIeU/BsfPVBra"
                         ]
                     },
                     "fs": {

config/config.go

@@ -4,12 +4,15 @@ package config
 import (
 	"encoding/json"
 	"errors"
+	"fmt"
 	"os"
 
 	log "github.com/fclairamb/go-log"
+	"github.com/tidwall/sjson"
 
 	"github.com/fclairamb/ftpserver/config/confpar"
 	"github.com/fclairamb/ftpserver/fs"
+	"golang.org/x/crypto/bcrypt"
 )
 
 // ErrUnknownUser is returned when the provided user cannot be identified through our authentication mechanism
@@ -82,9 +85,50 @@ func (c *Config) Load() error {
 
 	c.Content = &content
 
+	if c.Content.HashPlaintextPasswords {
+		c.HashPlaintextPasswords()
+	}
+
 	return c.Prepare()
 }
 
+func (c *Config) HashPlaintextPasswords() error {
+
+	json, errReadFile := os.ReadFile(c.fileName)
+	if errReadFile != nil {
+		c.logger.Error("Cannot read config file!", "err", errReadFile)
+		return errReadFile
+	}
+
+	save := false
+	for i, a := range c.Content.Accesses {
+		if a.User == "anonymous" && a.Pass == "*" {
+			continue
+		}
+		_, errCost := bcrypt.Cost([]byte(a.Pass))
+		if errCost != nil {
+			//This password is not hashed
+			hash, errHash := bcrypt.GenerateFromPassword([]byte(a.Pass), 10)
+			if errHash == nil {
+				modified, errJsonSet := sjson.Set(string(json), "accesses."+fmt.Sprint(i)+".pass", string(hash))
+				c.Content.Accesses[i].Pass = string(hash)
+				if errJsonSet == nil {
+					save = true
+					json = []byte(modified)
+				}
+			}
+		}
+	}
+	if save {
+		errWriteFile := os.WriteFile(c.fileName, json, 0644)
+		if errWriteFile != nil {
+			c.logger.Error("Cannot write config file!", "err", errWriteFile)
+			return errWriteFile
+		}
+	}
+	return nil
+}
+
 // Prepare the config before using it
 func (c *Config) Prepare() error {
 	ct := c.Content
@@ -116,8 +160,20 @@ func (c *Config) CheckAccesses() error {
 // GetAccess return a file system access given some credentials
 func (c *Config) GetAccess(user string, pass string) (*confpar.Access, error) {
 	for _, a := range c.Content.Accesses {
-		if a.User == user && (a.Pass == pass || (a.User == "anonymous" && a.Pass == "*")) {
-			return a, nil
+		if a.User == user {
+			_, errCost := bcrypt.Cost([]byte(a.Pass))
+			if errCost == nil {
+				//This user's password is bcrypted
+				errCompare := bcrypt.CompareHashAndPassword([]byte(a.Pass), []byte(pass))
+				if errCompare == nil {
+					return a, nil
+				}
+			} else {
+				//This user's password is plain-text
+				if a.Pass == pass || (a.User == "anonymous" && a.Pass == "*") {
+					return a, nil
+				}
+			}
 		}
 	}
 

config/confpar/confpar.go

@@ -50,6 +50,7 @@ type Content struct {
 	ListenAddress            string     `json:"listen_address"`              // Address to listen on
 	PublicHost               string     `json:"public_host"`                 // Public host to listen on
 	MaxClients               int        `json:"max_clients"`                 // Maximum clients who can connect
+	HashPlaintextPasswords   bool       `json:"hash_plaintext_passwords"`    // Overwrite plain-text passwords with hashed equivalents
 	Accesses                 []*Access  `json:"accesses"`                    // Accesses offered to users
 	PassiveTransferPortRange *PortRange `json:"passive_transfer_port_range"` // Listen port range
 	Logging                  Logging    `json:"logging"`                     // Logging parameters

go.mod

@@ -17,6 +17,13 @@ require (
 	golang.org/x/oauth2 v0.4.0
 )
 
+require (
+	github.com/tidwall/gjson v1.14.4 // indirect
+	github.com/tidwall/match v1.1.1 // indirect
+	github.com/tidwall/pretty v1.2.1 // indirect
+	github.com/tidwall/sjson v1.2.5 // indirect
+)
+
 require (
 	cloud.google.com/go/compute v1.7.0 // indirect
 	github.com/dropbox/dropbox-sdk-go-unofficial v5.6.0+incompatible // indirect

go.sum

@@ -639,6 +639,16 @@ github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.8.0 h1:pSgiaMZlXftHpm5L7V1+rVB+AZJydKsMxsQBIJw4PKk=
+github.com/tidwall/gjson v1.14.2/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
+github.com/tidwall/gjson v1.14.4 h1:uo0p8EbA09J7RQaflQ1aBRffTR7xedD2bcIVSYxLnkM=
+github.com/tidwall/gjson v1.14.4/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
+github.com/tidwall/match v1.1.1 h1:+Ho715JplO36QYgwN9PGYNhgZvoUSc9X2c80KVTi+GA=
+github.com/tidwall/match v1.1.1/go.mod h1:eRSPERbgtNPcGhD8UCthc6PmLEQXEWd3PRB5JTxsfmM=
+github.com/tidwall/pretty v1.2.0/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
+github.com/tidwall/pretty v1.2.1 h1:qjsOFOWWQl+N3RsoF5/ssm1pHmJJwhjlSbZ51I6wMl4=
+github.com/tidwall/pretty v1.2.1/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
+github.com/tidwall/sjson v1.2.5 h1:kLy8mja+1c9jlljvWTlSazM7cKDRfJuR/bOJhcY5NcY=
+github.com/tidwall/sjson v1.2.5/go.mod h1:Fvgq9kS/6ociJEDnK0Fk1cpYF4FIW6ZF7LAe+6jwd28=
 github.com/yuin/goldmark v1.1.25/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.1.32/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=