add vendoring

vendor/gitlab.com/etke.cc/go/validator/emails.go

@@ -0,0 +1,79 @@
+package validator
+
+import (
+	"net/mail"
+	"strings"
+
+	"gitlab.com/etke.cc/go/trysmtp"
+)
+
+// Email checks if email is valid
+func (v *V) Email(email string) bool {
+	// edge case: email may be optional
+	if email == "" {
+		return !v.enforce.Email
+	}
+
+	length := len(email)
+	// email cannot too short and too big
+	if length < 3 || length > 254 {
+		v.log.Info("email %s invalid, reason: length", email)
+		return false
+	}
+
+	_, err := mail.ParseAddress(email)
+	if err != nil {
+		v.log.Info("email %s invalid, reason: %v", email, err)
+		return false
+	}
+
+	emailb := []byte(email)
+	for _, spamregex := range v.spamlist {
+		if spamregex.Match(emailb) {
+			v.log.Info("email %s invalid, reason: spamlist", email)
+			return false
+		}
+	}
+
+	if v.emailMX(email) {
+		return false
+	}
+
+	smtpCheck := !v.emailSMTP(email)
+	if v.enforce.SMTP {
+		return smtpCheck
+	}
+
+	return true
+}
+
+func (v *V) emailMX(email string) bool {
+	at := strings.LastIndex(email, "@")
+	domain := email[at+1:]
+
+	nomx := !v.MX(domain)
+	if nomx {
+		v.log.Info("email %s domain %s invalid, reason: no MX", email, domain)
+		if v.enforce.MX {
+			return true
+		}
+	}
+
+	return false
+}
+
+func (v *V) emailSMTP(email string) bool {
+	client, err := trysmtp.Connect(v.from, email)
+	if err != nil {
+		if strings.HasPrefix(err.Error(), "45") {
+			v.log.Info("email %s may be invalid, reason: SMTP check (%v)", email, err)
+			return false
+		}
+
+		v.log.Info("email %s invalid, reason: SMTP check (%v)", email, err)
+		return true
+	}
+	defer client.Close()
+
+	return false
+}