feat: HTTP panel on :8000 with first admin setup

internal/auth/password.go

@@ -0,0 +1,45 @@
+package auth
+
+import (
+	"errors"
+	"regexp"
+	"unicode/utf8"
+
+	"golang.org/x/crypto/bcrypt"
+)
+
+var (
+	ErrPasswordTooShort = errors.New("password must be at least 8 characters")
+	ErrInvalidEmail     = errors.New("invalid email")
+	ErrInvalidUsername  = errors.New("username must be 3-64 characters: letters, digits, underscore")
+)
+
+var (
+	emailRegex    = regexp.MustCompile(`^[^\s@]+@[^\s@]+\.[^\s@]+$`)
+	usernameRegex = regexp.MustCompile(`^[a-zA-Z0-9_]{3,64}$`)
+)
+
+func HashPassword(password string) (string, error) {
+	if utf8.RuneCountInString(password) < 8 {
+		return "", ErrPasswordTooShort
+	}
+	hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
+	if err != nil {
+		return "", err
+	}
+	return string(hash), nil
+}
+
+func ValidateEmail(email string) error {
+	if !emailRegex.MatchString(email) {
+		return ErrInvalidEmail
+	}
+	return nil
+}
+
+func ValidateUsername(username string) error {
+	if !usernameRegex.MatchString(username) {
+		return ErrInvalidUsername
+	}
+	return nil
+}