Foro de elhacker.net

Buenas noches,
quería saber como podría validar un correo electrónico usando javascript, para validar emails hago usando PHP con el siguiente código:

function Validate_Email($email)
{
	$result = false;
 
	if(is_string($email))
	{
		if(filter_var($email, FILTER_VALIDATE_EMAIL))
		{
			$result = true;
		}
	}
 
	return $result;
}
 

La idea sería hacerlo lo más similar posible a como lo hago con PHP pero bueno tampoco quiero complicarlos...

FILTER_VALIDATE_EMAIL no es magia negra. Tiene un código detrás.

void php_filter_validate_email(PHP_INPUT_FILTER_PARAM_DECL) /* {{{ */
{
	/*
	 * The regex below is based on a regex by Michael Rushton.
	 * However, it is not identical.  I changed it to only consider routeable
	 * addresses as valid.  Michael's regex considers a@b a valid address
	 * which conflicts with section 2.3.5 of RFC 5321 which states that:
	 *
	 *   Only resolvable, fully-qualified domain names (FQDNs) are permitted
	 *   when domain names are used in SMTP.  In other words, names that can
	 *   be resolved to MX RRs or address (i.e., A or AAAA) RRs (as discussed
	 *   in Section 5) are permitted, as are CNAME RRs whose targets can be
	 *   resolved, in turn, to MX or address RRs.  Local nicknames or
	 *   unqualified names MUST NOT be used.
	 *
	 * This regex does not handle comments and folding whitespace.  While
	 * this is technically valid in an email address, these parts aren't
	 * actually part of the address itself.
	 *
	 * Michael's regex carries this copyright:
	 *
	 * Copyright © Michael Rushton 2009-10
	 * http://squiloople.com/
	 * Feel free to use and redistribute this code. But please keep this copyright notice.
	 *
	 */
	pcre2_code *re = NULL;
	pcre2_match_data *match_data = NULL;
	uint32_t capture_count;
	zend_string *sregexp;
	int rc;
	const char regexp0[] = "/^(?!(?:(?:\\x22?\\x5C[\\x00-\\x7E]\\x22?)|(?:\\x22?[^\\x5C\\x22]\\x22?)){255,})(?!(?:(?:\\x22?\\x5C[\\x00-\\x7E]\\x22?)|(?:\\x22?[^\\x5C\\x22]\\x22?)){65,}@)(?:(?:[\\x21\\x23-\\x27\\x2A\\x2B\\x2D\\x2F-\\x39\\x3D\\x3F\\x5E-\\x7E\\pL\\pN]+)|(?:\\x22(?:[\\x01-\\x08\\x0B\\x0C\\x0E-\\x1F\\x21\\x23-\\x5B\\x5D-\\x7F\\pL\\pN]|(?:\\x5C[\\x00-\\x7F]))*\\x22))(?:\\.(?:(?:[\\x21\\x23-\\x27\\x2A\\x2B\\x2D\\x2F-\\x39\\x3D\\x3F\\x5E-\\x7E\\pL\\pN]+)|(?:\\x22(?:[\\x01-\\x08\\x0B\\x0C\\x0E-\\x1F\\x21\\x23-\\x5B\\x5D-\\x7F\\pL\\pN]|(?:\\x5C[\\x00-\\x7F]))*\\x22)))*@(?:(?:(?!.*[^.]{64,})(?:(?:(?:xn--)?[a-z0-9]+(?:-+[a-z0-9]+)*\\.){1,126}){1,}(?:(?:[a-z][a-z0-9]*)|(?:(?:xn--)[a-z0-9]+))(?:-+[a-z0-9]+)*)|(?:\\[(?:(?:IPv6:(?:(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){7})|(?:(?!(?:.*[a-f0-9][:\\]]){7,})(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,5})?::(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,5})?)))|(?:(?:IPv6:(?:(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){5}:)|(?:(?!(?:.*[a-f0-9]:){5,})(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,3})?::(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,3}:)?)))?(?:(?:25[0-5])|(?:2[0-4][0-9])|(?:1[0-9]{2})|(?:[1-9]?[0-9]))(?:\\.(?:(?:25[0-5])|(?:2[0-4][0-9])|(?:1[0-9]{2})|(?:[1-9]?[0-9]))){3}))\\]))$/iDu";
	const char regexp1[] = "/^(?!(?:(?:\\x22?\\x5C[\\x00-\\x7E]\\x22?)|(?:\\x22?[^\\x5C\\x22]\\x22?)){255,})(?!(?:(?:\\x22?\\x5C[\\x00-\\x7E]\\x22?)|(?:\\x22?[^\\x5C\\x22]\\x22?)){65,}@)(?:(?:[\\x21\\x23-\\x27\\x2A\\x2B\\x2D\\x2F-\\x39\\x3D\\x3F\\x5E-\\x7E]+)|(?:\\x22(?:[\\x01-\\x08\\x0B\\x0C\\x0E-\\x1F\\x21\\x23-\\x5B\\x5D-\\x7F]|(?:\\x5C[\\x00-\\x7F]))*\\x22))(?:\\.(?:(?:[\\x21\\x23-\\x27\\x2A\\x2B\\x2D\\x2F-\\x39\\x3D\\x3F\\x5E-\\x7E]+)|(?:\\x22(?:[\\x01-\\x08\\x0B\\x0C\\x0E-\\x1F\\x21\\x23-\\x5B\\x5D-\\x7F]|(?:\\x5C[\\x00-\\x7F]))*\\x22)))*@(?:(?:(?!.*[^.]{64,})(?:(?:(?:xn--)?[a-z0-9]+(?:-+[a-z0-9]+)*\\.){1,126}){1,}(?:(?:[a-z][a-z0-9]*)|(?:(?:xn--)[a-z0-9]+))(?:-+[a-z0-9]+)*)|(?:\\[(?:(?:IPv6:(?:(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){7})|(?:(?!(?:.*[a-f0-9][:\\]]){7,})(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,5})?::(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,5})?)))|(?:(?:IPv6:(?:(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){5}:)|(?:(?!(?:.*[a-f0-9]:){5,})(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,3})?::(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,3}:)?)))?(?:(?:25[0-5])|(?:2[0-4][0-9])|(?:1[0-9]{2})|(?:[1-9]?[0-9]))(?:\\.(?:(?:25[0-5])|(?:2[0-4][0-9])|(?:1[0-9]{2})|(?:[1-9]?[0-9]))){3}))\\]))$/iD";
	const char *regexp;
	size_t regexp_len;
 
	if (flags & FILTER_FLAG_EMAIL_UNICODE) {
		regexp = regexp0;
		regexp_len = sizeof(regexp0) - 1;
	} else {
		regexp = regexp1;
		regexp_len = sizeof(regexp1) - 1;
	}
 
	/* The maximum length of an e-mail address is 320 octets, per RFC 2821. */
	if (Z_STRLEN_P(value) > 320) {
		RETURN_VALIDATION_FAILED
	}
 
	sregexp = zend_string_init(regexp, regexp_len, 0);
	re = pcre_get_compiled_regex(sregexp, &capture_count);
	zend_string_release_ex(sregexp, 0);
	if (!re) {
		RETURN_VALIDATION_FAILED
	}
	match_data = php_pcre_create_match_data(capture_count, re);
	if (!match_data) {
		RETURN_VALIDATION_FAILED
	}
	rc = pcre2_match(re, (PCRE2_SPTR)Z_STRVAL_P(value), Z_STRLEN_P(value), 0, 0, match_data, php_pcre_mctx());
	php_pcre_free_match_data(match_data);
 
	/* 0 means that the vector is too small to hold all the captured substring offsets */
	if (rc < 0) {
		RETURN_VALIDATION_FAILED
	}
 
}
/* }}} */

Pórtalo a javascript. Si quieres que te quede más limpio el código para trabajar crea una carpetas libs y añades el código con Etiqueta script src ="libs/filtros/f_email.js">finEtiquetaScript

No tiene mucho sentido utilizar la de PHP, demasiado complicado y de hecho creo que los flags ni siquiera son compatibles. Puedes usar el estándar oficial (RFC 2822) y a correr.

function validateEmail(email) {
    var re = /^[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?$/;
    return re.test(String(email).toLowerCase());
}

https://stackoverflow.com/a/1373724/1974385

Saludos

Hola! ¿Es decir la función PHP que uso para validar los correos no es segura? ¿o para usarlo en javascript no es recomendable?

Simplemente es un overkill, es segura, pero implementarla tal cual esta implementada en PHP seria invertir demasiado tiempo para algo que ya esta hecho de otras formas.

Saludos