Initial commit: Open sourcing all of the Maple Open Technologies code.

cloud/maplefile-backend/pkg/validation/email.go

@@ -0,0 +1,105 @@
+// Package validation provides shared input validation utilities.
+package validation
+
+import (
+	"net"
+	"net/mail"
+	"strings"
+)
+
+// ValidateEmail validates an email address using Go's standard mail package.
+// Returns an error message if the email is invalid, or an empty string if valid.
+// This provides consistent email validation across all services.
+func ValidateEmail(email string) string {
+	email = strings.TrimSpace(email)
+	if email == "" {
+		return "Email address is required"
+	}
+
+	// Use Go's mail package for proper RFC 5322 email validation
+	if _, err := mail.ParseAddress(email); err != nil {
+		return "Please enter a valid email address"
+	}
+
+	return ""
+}
+
+// IsValidEmail returns true if the email is valid, false otherwise.
+// This is a convenience wrapper around ValidateEmail for simple boolean checks.
+func IsValidEmail(email string) bool {
+	return ValidateEmail(email) == ""
+}
+
+// MaskEmail masks an email address for safe logging.
+// Example: "john.doe@example.com" becomes "jo***@example.com"
+// This prevents PII exposure in logs while still allowing identification.
+func MaskEmail(email string) string {
+	email = strings.TrimSpace(email)
+	if email == "" {
+		return "***"
+	}
+
+	parts := strings.Split(email, "@")
+	if len(parts) != 2 {
+		return "***"
+	}
+
+	localPart := parts[0]
+	domain := parts[1]
+
+	// Mask local part based on length
+	var maskedLocal string
+	switch {
+	case len(localPart) <= 1:
+		maskedLocal = "*"
+	case len(localPart) <= 3:
+		maskedLocal = localPart[:1] + "***"
+	default:
+		maskedLocal = localPart[:2] + "***"
+	}
+
+	return maskedLocal + "@" + domain
+}
+
+// MaskIP masks an IP address for safe logging.
+// IPv4 example: "192.168.1.100" becomes "192.168.1.***"
+// IPv6 example: "2001:db8::1" becomes "2001:db8::***"
+// This prevents PII exposure in logs while still allowing network identification.
+func MaskIP(ip string) string {
+	ip = strings.TrimSpace(ip)
+	if ip == "" {
+		return "***"
+	}
+
+	// Remove port if present (format: "IP:port" or "[IPv6]:port")
+	host, _, err := net.SplitHostPort(ip)
+	if err == nil {
+		ip = host
+	}
+
+	// Parse to determine if IPv4 or IPv6
+	parsedIP := net.ParseIP(ip)
+	if parsedIP == nil {
+		return "***"
+	}
+
+	// Check if IPv4
+	if ipv4 := parsedIP.To4(); ipv4 != nil {
+		// Mask last octet: 192.168.1.100 -> 192.168.1.***
+		parts := strings.Split(ip, ".")
+		if len(parts) == 4 {
+			return parts[0] + "." + parts[1] + "." + parts[2] + ".***"
+		}
+		return "***"
+	}
+
+	// IPv6: mask last segment
+	// Example: 2001:db8:85a3::8a2e:370:7334 -> 2001:db8:85a3::8a2e:370:***
+	parts := strings.Split(ip, ":")
+	if len(parts) > 1 {
+		parts[len(parts)-1] = "***"
+		return strings.Join(parts, ":")
+	}
+
+	return "***"
+}