gh0stwizard / libeav Goto Github PK

Following functions will both output 1, i.e valid emails

int try_rfc_6531() {
  eav_t eav;
  eav_init(&eav);
  eav.tld_check = false;
  eav.rfc = EAV_RFC_6531;
  eav_setup(&eav);
  const char eml[] = "abc@def_ghi.us";
  int len = sizeof(eml) - 1;
  int ret = eav_is_email(&eav, eml, len);
  eav_free(&eav);
  return ret;
}

int try_rfc_5321() {
  eav_t eav;
  eav_init(&eav);
  eav.tld_check = false;
  eav.rfc = EAV_RFC_5321;
  eav_setup(&eav);
  const char eml[] = "abc@def_ghi.us";
  int len = sizeof(eml) - 1;
  int ret = eav_is_email(&eav, eml, len);
  eav_free(&eav);
  return ret;
}

int main() {
    printf("rfc-6531 for underscore=%d\nrfc-5321 for underscore=%d",
    try_rfc_6531(), try_rfc_5321());
    return 0;
}

but as per RFC 5321, an email address's domain part cannot contain _ and this RFC particularly mentions this restriction:

To promote interoperability and consistent with long-standing
guidance about conservative use of the DNS in naming and applications
(e.g., see Section 2.3.1 of the base DNS document, RFC 1035 [2]),
characters outside the set of alphabetic characters, digits, and
hyphen MUST NOT appear in domain name labels for SMTP clients or
servers. In particular, the underscore character is not permitted.
SMTP servers that receive a command in which invalid character codes
have been employed, and for which there are no other reasons for
rejection, MUST reject that command with a 501 response (this rule,
like others, could be overridden by appropriate SMTP extensions).

So I think it may be an issue in current implemention.

By the way, thank you for your great library, it helped a lot :P