db: split password & user

cmd/rushlink/main.go

@@ -32,6 +32,10 @@ func main() {
 		log.Fatal(errors.Wrap(err, "migrating database"))
 	}
 
+	if err := db.CreateAdminUser(database, "admin"); err != nil {
+		log.Fatalln(err)
+	}
+
 	go rushlink.StartMetricsServer(*metricsListen, database, filestore)
 	rushlink.StartMainServer(*httpListen, database, filestore, *rootURL)
 }

handlers.go

@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"strconv"
 	"strings"
 	"time"
 
@@ -244,6 +245,12 @@ func (rl *rushlink) viewActionSuccess(w http.ResponseWriter, r *http.Request, p
 }
 
 func (rl *rushlink) newPasteHandler(w http.ResponseWriter, r *http.Request) {
+	// Check if the user is authenticated
+	user := rl.authenticateUser(w, r, false, nil)
+	if user == nil {
+		return
+	}
+
 	if err := r.ParseMultipartForm(formParseMaxMemory); err != nil {
 		msg := fmt.Sprintf("could not parse form: %v\n", err)
 		rl.renderError(w, r, http.StatusBadRequest, msg)
@@ -262,7 +269,7 @@ func (rl *rushlink) newPasteHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	if shortensPrs {
-		rl.newRedirectPasteHandler(w, r, shortens[0])
+		rl.newRedirectPasteHandler(w, r, user, shortens[0])
 		return
 	}
 	if fileHeadersPrs {
@@ -272,17 +279,163 @@ func (rl *rushlink) newPasteHandler(w http.ResponseWriter, r *http.Request) {
 			rl.renderInternalServerError(w, r, err)
 			return
 		}
-		rl.newFileUploadPasteHandler(w, r, file, *fileHeader)
+		rl.newFileUploadPasteHandler(w, r, user, file, *fileHeader)
 		return
 	}
 }
+func (rl *rushlink) createUserHandler(w http.ResponseWriter, r *http.Request) {
+	// Check if the user is authenticated as an admin
+	user := rl.authenticateUser(w, r, true, nil)
+	if user == nil {
+		return
+	}
 
-func (rl *rushlink) newFileUploadPasteHandler(w http.ResponseWriter, r *http.Request, file multipart.File, header multipart.FileHeader) {
+	if err := r.ParseMultipartForm(formParseMaxMemory); err != nil {
+		msg := fmt.Sprintf("could not parse form: %v\n", err)
+		rl.renderError(w, r, http.StatusBadRequest, msg)
+		return
+	}
+
+	new_username := r.FormValue("username")
+	new_password := r.FormValue("password")
+	new_admin, _ := strconv.ParseBool(r.FormValue("admin"))
+
+	// Create the user
+	if err := db.NewUser(rl.db, new_username, new_password, new_admin); err != nil {
+		// Failed to create the user, return a 500 Internal Server Error response
+		http.Error(w, "Failed to create user", http.StatusInternalServerError)
+		return
+	}
+
+	// Return a 201 Created response
+	w.WriteHeader(http.StatusCreated)
+}
+
+func (rl *rushlink) setWWWAuthenticate(w http.ResponseWriter, r *http.Request) {
+	// Set authentication headers for Basic Authentication
+	w.Header().Set("WWW-Authenticate", `Basic realm="Restricted"`)
+	w.WriteHeader(http.StatusUnauthorized)
+}
+
+func (rl *rushlink) authenticateUser(w http.ResponseWriter, r *http.Request, shouldBeAdmin bool, canAlsoBe *string) *db.User {
+	// Check if the user is authenticated
+	username, password, ok := r.BasicAuth()
+	if !ok {
+		// User is not authenticated, return a 401 Unauthorized response
+		rl.setWWWAuthenticate(w, r)
+		return nil
+	}
+
+	// Authenticate the user
+	user, err := db.Authenticate(rl.db, username, password)
+	if err != nil {
+		rl.setWWWAuthenticate(w, r)
+		log.Printf("authentication failure: %s", err)
+		return nil
+	}
+
+	if (shouldBeAdmin && !user.Admin && (canAlsoBe == nil || *canAlsoBe != user.User)) {
+		// Authentication failed, return a 401 Unauthorized response
+		rl.setWWWAuthenticate(w, r)
+		log.Printf("user '%s' should be admin (or '%s'), but isn't", username, canAlsoBe)
+		return nil
+	}
+	return user
+}
+func (rl *rushlink) deleteUserHandler(w http.ResponseWriter, r *http.Request) {
+	// Parse the user ID from the request URL
+	vars := mux.Vars(r)
+	userName := vars["user"]
+
+	// Check if the user is authenticated as an admin or self
+	user := rl.authenticateUser(w, r, true, &userName)
+	if user == nil {
+		return
+	}
+
+	// Delete the user
+	if err := db.DeleteUser(rl.db, userName); err != nil {
+		// Failed to delete the user, return a 500 Internal Server Error response
+		http.Error(w, "Failed to delete user", http.StatusInternalServerError)
+		return
+	}
+
+	// Return a 204 No Content response
+	w.WriteHeader(http.StatusNoContent)
+}
+func (rl *rushlink) changeUserHandler(w http.ResponseWriter, r *http.Request) {
+	// Parse the user ID from the request URL
+	vars := mux.Vars(r)
+	userName := vars["user"]
+
+	// Check if the user is authenticated as an admin or self
+	user := rl.authenticateUser(w, r, true, &userName)
+	if user == nil {
+		return
+	}
+
+	// Parse the request multipart form
+	if err := r.ParseMultipartForm(formParseMaxMemory); err != nil {
+		msg := fmt.Sprintf("could not parse form: %v\n", err)
+		rl.renderError(w, r, http.StatusBadRequest, msg)
+		return
+	}
+
+	// Get the user record from the database
+	updatedUser := new(db.User)
+	if err := rl.db.Where("user = ?", userName).First(&updatedUser).Error; err != nil {
+		// User record not found, return a 404 Not Found response
+		http.NotFound(w, r)
+		return
+	}
+
+	// Get the updated user data from the form
+	if newUsername := r.FormValue("new_username"); newUsername != "" {
+		updatedUser.User = newUsername
+	}
+	if newPassword := r.FormValue("new_password"); newPassword != "" {
+		hashedPassword, err := db.HashPassword(newPassword)
+		if err != nil {
+			msg := fmt.Sprintf("could not hash password: %v\n", err)
+			rl.renderError(w, r, http.StatusInternalServerError, msg)
+			return
+		}
+		updatedUser.Password = hashedPassword
+	}
+	if newAdminStr := r.FormValue("new_admin"); newAdminStr != "" {
+		newAdmin, err := strconv.ParseBool(newAdminStr)
+		if err != nil {
+			msg := fmt.Sprintf("could not parse admin status: %v\n", err)
+			rl.renderError(w, r, http.StatusBadRequest, msg)
+			return
+		}
+		updatedUser.Admin = newAdmin
+	}
+
+	// Check if the user is trying to update their own admin status
+	if updatedUser.Admin && !user.Admin {
+		// User is trying to update their own admin status, return a 403 Forbidden response
+		http.Error(w, "You do not have permission to update your own admin status", http.StatusForbidden)
+		return
+	}
+
+	// Update the user in the database
+	if err := db.ChangeUser(rl.db, userName, updatedUser); err != nil {
+		// Failed to update the user, return a 500 Internal Server Error response
+		http.Error(w, "Failed to update user", http.StatusInternalServerError)
+		return
+	}
+
+	// Return a 200 OK response
+	w.WriteHeader(http.StatusOK)
+}
+
+func (rl *rushlink) newFileUploadPasteHandler(w http.ResponseWriter, r *http.Request, user *db.User, file multipart.File, header multipart.FileHeader) {
 	var fu *db.FileUpload
 	var paste *db.Paste
 	if err := rl.db.Transaction(func(tx *db.Database) error {
 		var err error
-		fu, err = db.NewFileUpload(rl.fs, file, header.Filename)
+		fu, err = db.NewFileUpload(rl.fs, file, user, header.Filename)
 		if err != nil {
 			panic(errors.Wrap(err, "creating fileUpload"))
 		}
@@ -290,7 +443,7 @@ func (rl *rushlink) newFileUploadPasteHandler(w http.ResponseWriter, r *http.Req
 			panic(errors.Wrap(err, "saving fileUpload in db"))
 		}
 
-		paste, err = shortenFileUploadID(tx, fu.PubID)
+		paste, err = shortenFileUploadID(tx, user, fu.PubID)
 		return err
 	}); err != nil {
 		panic(err)
@@ -298,7 +451,7 @@ func (rl *rushlink) newFileUploadPasteHandler(w http.ResponseWriter, r *http.Req
 	rl.viewActionSuccess(w, r, paste, fu)
 }
 
-func (rl *rushlink) newRedirectPasteHandler(w http.ResponseWriter, r *http.Request, rawurl string) {
+func (rl *rushlink) newRedirectPasteHandler(w http.ResponseWriter, r *http.Request, user *db.User, rawurl string) {
 	userURL, err := url.Parse(rawurl)
 	if err != nil {
 		msg := fmt.Sprintf("invalid url (%v): %v", err, rawurl)
@@ -317,7 +470,7 @@ func (rl *rushlink) newRedirectPasteHandler(w http.ResponseWriter, r *http.Reque
 	var paste *db.Paste
 	if err := rl.db.Transaction(func(tx *db.Database) error {
 		var err error
-		paste, err = shortenURL(tx, userURL)
+		paste, err = shortenURL(tx, user, userURL)
 		return err
 	}); err != nil {
 		panic(err)
@@ -370,19 +523,19 @@ func (rl *rushlink) deletePasteHandler(w http.ResponseWriter, r *http.Request) {
 //
 // Returns the new paste key if the fileUpload was successfully added to the
 // database
-func shortenFileUploadID(tx *db.Database, id uuid.UUID) (*db.Paste, error) {
-	return shorten(tx, db.PasteTypeFileUpload, id[:])
+func shortenFileUploadID(tx *db.Database, user *db.User, id uuid.UUID) (*db.Paste, error) {
+	return shorten(tx, user, db.PasteTypeFileUpload, id[:])
 }
 
 // Add a new URL to the database
 //
 // Returns the new paste key if the url was successfully shortened
-func shortenURL(tx *db.Database, userURL *url.URL) (*db.Paste, error) {
-	return shorten(tx, db.PasteTypeRedirect, []byte(userURL.String()))
+func shortenURL(tx *db.Database, user *db.User, userURL *url.URL) (*db.Paste, error) {
+	return shorten(tx, user, db.PasteTypeRedirect, []byte(userURL.String()))
 }
 
 // Add a paste (of any kind) to the database with arbitrary content.
-func shorten(tx *db.Database, ty db.PasteType, content []byte) (*db.Paste, error) {
+func shorten(tx *db.Database, user *db.User, ty db.PasteType, content []byte) (*db.Paste, error) {
 	// Generate the paste key
 	var keyEntropy int
 	if ty == db.PasteTypeFileUpload || ty == db.PasteTypePaste {
@@ -403,6 +556,7 @@ func shorten(tx *db.Database, ty db.PasteType, content []byte) (*db.Paste, error
 	p := db.Paste{
 		Type:        ty,
 		State:       db.PasteStatePresent,
+		CreatedBy:   user.ID,
 		Content:     content,
 		Key:         pasteKey,
 		DeleteToken: deleteToken,

internal/db/fileupload.go

@@ -38,6 +38,9 @@ type FileUpload struct {
 	// UUID publically identifies this FileUpload.
 	PubID uuid.UUID `gorm:"uniqueIndex"`
 
+	// User ID that created this file
+	CreatedBy uint `gorm:"index"`
+
 	// FileName contains the original filename of this FileUpload.
 	FileName string
 
@@ -126,7 +129,7 @@ func (fs *FileStore) filePath(pubID uuid.UUID, fileName string) string {
 //
 // Internally, this function detects the type of the file stored in `r` using
 // `http.DetectContentType`.
-func NewFileUpload(fs *FileStore, r io.Reader, fileName string) (*FileUpload, error) {
+func NewFileUpload(fs *FileStore, r io.Reader, user *User, fileName string) (*FileUpload, error) {
 	// Generate a file ID
 	pubID, err := uuid.NewRandom()
 	if err != nil {
@@ -168,6 +171,7 @@ func NewFileUpload(fs *FileStore, r io.Reader, fileName string) (*FileUpload, er
 	fu := &FileUpload{
 		State:       FileUploadStatePresent,
 		PubID:       pubID,
+		CreatedBy:   user.ID,
 		FileName:    baseName,
 		ContentType: contentType,
 		Checksum:    hash.Sum32(),

internal/db/migrate.go

@@ -42,5 +42,56 @@ func Gormigrate(db *gorm.DB) *gormigrate.Gormigrate {
 				return tx.Migrator().DropTable(&FileUpload{}, &Paste{})
 			},
 		},
+		{
+			ID: "202304301337",
+			Migrate: func(tx *gorm.DB) error {
+				type User struct {
+					ID        uint   `gorm:"primaryKey"`
+					User      string `gorm:"uniqueIndex"`
+					Password  string
+					Admin     bool
+					CreatedAt time.Time
+					UpdatedAt time.Time
+					DeletedAt gorm.DeletedAt
+				}
+				type FileUpload struct {
+					ID          uint            `gorm:"primaryKey"`
+					State       FileUploadState `gorm:"index"`
+					PubID       uuid.UUID       `gorm:"uniqueIndex"`
+					CreatedBy   uint            `gorm:"index"`
+					FileName    string
+					ContentType string
+					Checksum    uint32
+					CreatedAt   time.Time
+					UpdatedAt   time.Time
+					DeletedAt   gorm.DeletedAt
+				}
+				type Paste struct {
+					ID          uint       `gorm:"primaryKey"`
+					Type        PasteType  `gorm:"index"`
+					State       PasteState `gorm:"index"`
+					CreatedBy   uint       `gorm:"index"`
+					Content     []byte
+					Key         string `gorm:"uniqueIndex"`
+					DeleteToken string
+					CreatedAt   time.Time
+					UpdatedAt   time.Time
+					DeletedAt   gorm.DeletedAt
+				}
+				return tx.AutoMigrate(&User{}, &FileUpload{}, &Paste{})
+			},
+			Rollback: func(tx *gorm.DB) error {
+				if err := tx.Migrator().DropTable(&User{}); err != nil {
+					return err
+				}
+				if err := tx.Migrator().DropColumn(&FileUpload{}, "CreatedBy"); err != nil {
+					return err
+				}
+				if err := tx.Migrator().DropColumn(&Paste{}, "CreatedBy"); err != nil {
+					return err
+				}
+				return nil
+			},
+		},
 	})
 }

internal/db/password.go

@@ -0,0 +1,72 @@
+package db
+
+import (
+	"crypto/rand"
+	"crypto/subtle"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"strings"
+
+	"golang.org/x/crypto/argon2"
+)
+
+const (
+	pwdSaltSize = 16
+	pwdHashSize = 32
+
+	// chosen from https://cheatsheetseries.owasp.org/cheatsheets/Password_Storage_Cheat_Sheet.html
+	pwdMemory   = 64 * 1024
+	pwdThreads  = 1
+	pwdIterations = 2
+	pwdParams   = "m=65536,t=2,p=1,v=19"
+	pwdVersion  = "v=19"
+	pwdAlgo     = "argon2id"
+)
+
+func HashPassword(password string) (string, error) {
+	if argon2.Version != 19 {
+		// go has no static asserts
+		panic("Unexpected argon2 version")
+	}
+	// Generate a salt for the password hash
+	salt := make([]byte, pwdSaltSize)
+	if _, err := rand.Read(salt); err != nil {
+		return "", err
+	}
+
+	// Hash the password using argon2id
+	hash := argon2.IDKey([]byte(password), salt, pwdIterations, pwdMemory, pwdThreads, pwdHashSize)
+
+	// Encode the salt and hash as a string in PHC format
+	encodedSalt := base64.RawStdEncoding.EncodeToString(salt)
+	encodedHash := base64.RawStdEncoding.EncodeToString(hash)
+	return fmt.Sprintf("$%s$%s$%s$%s$%s", pwdAlgo, pwdVersion, pwdParams, encodedSalt, encodedHash), nil
+}
+
+var errInvalidDBPasswordFormat = errors.New("invalid password format in db")
+
+func comparePassword(hashedPassword string, password string) (bool, error) {
+	// Extract the salt and hash from the hashed password string
+	fields := strings.Split(hashedPassword, "$")
+	if len(fields) != 6 || fields[1] != pwdAlgo || fields[2] != pwdVersion || fields[3] != pwdParams {
+		return false, errInvalidDBPasswordFormat
+	}
+	encodedSalt, encodedHash := fields[4], fields[5]
+
+	// Decode the salt and hash from base64
+	salt, err := base64.RawStdEncoding.DecodeString(encodedSalt)
+	if err != nil {
+		return false, err
+	}
+	hash, err := base64.RawStdEncoding.DecodeString(encodedHash)
+	if err != nil {
+		return false, err
+	}
+
+	// Hash the password using the extracted salt and parameters
+	computedHash := argon2.IDKey([]byte(password), salt, pwdIterations, pwdMemory, pwdThreads, pwdHashSize)
+
+	// Compare the computed hash with the stored hash
+	return subtle.ConstantTimeCompare(hash, computedHash) == 1, nil
+}

internal/db/paste.go

@@ -24,6 +24,7 @@ type Paste struct {
 	ID          uint       `gorm:"primaryKey"`
 	Type        PasteType  `gorm:"index"`
 	State       PasteState `gorm:"index"`
+	CreatedBy   uint       `gorm:"index"`
 	Content     []byte
 	Key         string `gorm:"uniqueIndex"`
 	DeleteToken string

internal/db/user.go

@@ -0,0 +1,129 @@
+package db
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/google/uuid"
+	"gorm.io/gorm"
+)
+
+type User struct {
+	ID        uint   `gorm:"primaryKey"`
+	User      string `gorm:"uniqueIndex"`
+	Password  string
+	Admin     bool
+	CreatedAt time.Time
+	UpdatedAt time.Time
+	DeletedAt gorm.DeletedAt
+}
+
+func NewUser(db *gorm.DB, username string, password string, admin bool) error {
+	// Generate a new UUID for the user
+	id, err := uuid.NewRandom()
+	if err != nil {
+		return err
+	}
+
+	// Hash the password using argon2id
+	hashedPassword, err := HashPassword(password)
+	if err != nil {
+		return err
+	}
+
+	// Create a new user record
+	user := &User{
+		ID:       uint(id.ID()),
+		User:     username,
+		Password: hashedPassword,
+		Admin:    admin,
+	}
+	return db.Create(user).Error
+}
+
+func Authenticate(db *gorm.DB, username string, password string) (*User, error) {
+	// Get the user record by username
+	var user User
+	if err := db.Where("user = ?", username).First(&user).Error; err != nil {
+		return nil, errors.New("user not found")
+	}
+
+	// Compare the hashed password with the provided password
+	valid, err := comparePassword(user.Password, password)
+	if err != nil {
+		return nil, err
+	}
+	if !valid {
+		return nil, errors.New("invalid password")
+	}
+
+	return &user, nil
+}
+
+// DeleteUser deletes a user with the specified username from the database.
+func DeleteUser(db *gorm.DB, username string) error {
+	// Find the user by username
+	var user User
+	if err := db.Where("user = ?", username).First(&user).Error; err != nil {
+		return err
+	}
+
+	// Delete the user
+	if err := db.Delete(&user).Error; err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func ChangeUser(db *gorm.DB, username string, updatedUser *User) error {
+	// Retrieve the existing user
+	var existingUser User
+	if err := db.Where("user = ?", username).First(&existingUser).Error; err != nil {
+		return err
+	}
+
+	// Update the user fields
+	existingUser.User = updatedUser.User
+	existingUser.Password = updatedUser.Password
+	existingUser.Admin = updatedUser.Admin
+
+	// Save the updated user to the database
+	if err := db.Save(&existingUser).Error; err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func CreateAdminUser(db *gorm.DB, adminUsername string) error {
+	// Check if the admin user already exists
+	var admins []User
+	if err := db.Unscoped().Limit(1).Where("user = ?", adminUsername).Find(&admins).Error; err != nil {
+		return err
+	}
+	if len(admins) > 0 {
+		// already exists
+		return nil
+	}
+
+	// Generate a random 24-char password
+	passwordBytes := make([]byte, 24)
+	if _, err := rand.Read(passwordBytes); err != nil {
+		return err
+	}
+	password := base64.URLEncoding.EncodeToString(passwordBytes)
+
+	// Create the admin user
+	if err := NewUser(db, adminUsername, password, true); err != nil {
+		return err
+	}
+
+	// Print out the generated password
+	fmt.Printf("Generated password for admin user %s: %s\n", adminUsername, password)
+
+	return nil
+}

router.go

@@ -106,6 +106,9 @@ func InitMainRouter(r *mux.Router, rl *rushlink) {
 	r.HandleFunc("/{path:js/"+staticFilenameExpr+"}", rl.staticGetHandler).Methods("GET", "HEAD")
 	r.HandleFunc("/", rl.indexGetHandler).Methods("GET", "HEAD")
 	r.HandleFunc("/", rl.newPasteHandler).Methods("POST")
+	r.HandleFunc("/users", rl.createUserHandler).Methods("POST")
+	r.HandleFunc("/users/{user}", rl.changeUserHandler).Methods("POST")
+	r.HandleFunc("/users/{user}", rl.deleteUserHandler).Methods("DELETE")
 	r.HandleFunc("/"+urlKeyExpr, rl.viewPasteHandler).Methods("GET", "HEAD")
 	r.HandleFunc("/"+urlKeyWithExtExpr, rl.viewPasteHandler).Methods("GET", "HEAD")
 	r.HandleFunc("/"+urlKeyExpr+"/nr", rl.viewPasteHandlerNoRedirect).Methods("GET", "HEAD")