Add users system, required for uploading new pastes

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/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 +1,153 @@
+package db
+
+import (
+	"bytes"
+	"crypto/rand"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/google/uuid"
+	"golang.org/x/crypto/argon2"
+	"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
+	if !comparePassword(user.Password, password) {
+		return nil, errors.New("invalid password")
+	}
+
+	return &user, nil
+}
+
+func HashPassword(password string) (string, error) {
+	// Generate a salt for the password hash
+	salt := make([]byte, 16)
+	if _, err := rand.Read(salt); err != nil {
+		return "", err
+	}
+
+	// Hash the password using argon2id
+	hash := argon2.IDKey([]byte(password), salt, 2, 64*1024, 1, 64)
+
+	// Encode the salt and hash as a string
+	return string(salt) + string(hash), nil
+}
+
+func comparePassword(hashedPassword string, password string) bool {
+	// Decode the salt and hash from the hashed password string
+	salt := []byte(hashedPassword)[:16]
+	hash := []byte(hashedPassword)[16:]
+
+	// Hash the password using the same salt and parameters
+	computedHash := argon2.IDKey([]byte(password), salt, 2, 64*1024, 1, 64)
+
+	// Compare the computed hash with the stored hash
+	return bytes.Equal(hash, computedHash)
+}
+
+// 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
+}