init

internal/auth/password.go

@@ -0,0 +1,35 @@
+package auth
+
+import (
+	"fmt"
+	"strings"
+
+	"golang.org/x/crypto/bcrypt"
+)
+
+const bcryptCost = 12
+
+func HashPassword(password string) (string, error) {
+	if strings.TrimSpace(password) == "" {
+		return "", fmt.Errorf("password is required")
+	}
+
+	if len(password) > 72 {
+		return "", fmt.Errorf("password must be 72 bytes or fewer")
+	}
+
+	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(password), bcryptCost)
+	if err != nil {
+		return "", fmt.Errorf("hash password: %w", err)
+	}
+
+	return string(hashedPassword), nil
+}
+
+func ComparePassword(hash, password string) error {
+	if hash == "" {
+		return fmt.Errorf("password hash is required")
+	}
+
+	return bcrypt.CompareHashAndPassword([]byte(hash), []byte(password))
+}