이메일 주소 형식 검증하기
이메일 주소 검증 코드를 짤 일이 있어 작업한 기록을 남긴다
email regex php
정규식을 얻어와 복붙하자
정규식을 일일이 작성하기는 귀찮은 노릇이니 emailregex.com에서 정규식을 얻었다.
구글에서 verify email address with regex로 검색하면 바로 나오는 사이트인데,
타이틀이 굉장히 자신감 넘친다.
"Email Address Regular Expression That 99.99% Works."
들어가보면 이메일 형식 검증을 위한 정규식을 여러 언어별로 소개하고 있다.
일단 나는 오늘 php로 작업했으므로 php 이메일 정규식을 복사했다.
/^(?!(?:(?:\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\x
23-\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-z
0-9]+))(?:-[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}))\]))$/iD
1070 글자나 된다.
어쨌건 복붙하고 다음과 같은 함수를 작성하였다.
private const EMAIL_REGEX = '/^.....$/iD'; // 길어서 생략
public function isValidAddress(string $address): bool
{
return !empty($address) && preg_match(self::EMAIL_REGEX, $address);
}
테스트 케이스도 작성하자
제대로 돌아가는지 확인하기 위해 kahlan을 써서 테스트 코드도 작성하였다.
테스트 케이스는 MSDN의 Email Address test cases을 거의 그대로 가져다 썼다.
인덴트가 많아서 고의로 인덴트를 2 space로 표현하였다.
describe('isValid', function() {
context('with valid email addresses', function(){
given('addresses', function () {
// see: https://blogs.msdn.microsoft.com/testing123/2009/02/06/email-address-test-cases/
return [
'email@domain.com' , // Valid email
'firstname.lastname@domain.com', // Email contains dot in the address field
'email@subdomain.domain.com', // Email contains dot with subdomain
'firstname+lastname@domain.com', // Plus sign is considered valid character
'email@123.123.123.123', // Domain is valid IP address
'email@[123.123.123.123]', // Square bracket around IP address is considered valid
'"email"@domain.com', // Quotes around email is considered valid
'1234567890@domain.com', // Digits in address are valid
'email@domain-one.com', // Dash in domain name is valid
'_______@domain.com', // Underscore in the address field is valid
'email@domain.name', // .name is valid Top Level Domain name
'email@domain.co.jp', // Dot in Top Level Domain name also considered valid (use co.jp as example here)
'firstname-lastname@domain.com' // Dash in address field is valid
];
});
it('returns true', function(){
foreach ($this->addresses as $address) {
expect($this->emailUtil->isValidAddress($address))->toBeTruthy();
}
});
});
context('with invalid email addresses', function(){
given('addresses', function () {
// see: https://blogs.msdn.microsoft.com/testing123/2009/02/06/email-address-test-cases/
return [
'',
' ',
'123',
'plainaddress', // Missing @ sign and domain
'#@%^%#$@#$@#.com', // Garbage
'@domain.com', // Missing username
'Joe Smith <email@domain.com>', // Encoded html within email is invalid
'email.domain.com', // Missing @
'email@domain@domain.com', // Two @ sign
'.email@domain.com', // Leading dot in address is not allowed
'email.@domain.com', // Trailing dot in address is not allowed
'email..email@domain.com', // Multiple dots
'あいうえお@domain.com', // Unicode char as address
'email@domain.com (Joe Smith)', // Text followed email is not allowed
'email@domain', // Missing top level domain (.com/.net/.org/etc)
'email@-domain.com', // Leading dash in front of domain is invalid
'email@111.222.333.44444', // Invalid IP format
'email@domain..com', // Multiple dot in the domain portion is invalid
];
});
it('returns false', function(){
foreach ($this->addresses as $address) {
expect($this->emailUtil->isValidAddress($address))->toBeFalsy();
}
});
});
});
테스트 케이스가 실패하니 정규식을 고치자
그런데 with valid email addresses의
email@123.123.123.123, email@[123.123.123.123]에서 테스트가 실패한다!
99.99% 통하는 정규식이라더니 이 두 케이스가 0.01% 에 해당하는 경우인 모양이다.
하는 수 없지. 정규식을 수정해서 쓰기로 했다.
저 두 경우만 통과하면 되니까 |과 함께 집어넣으면 될 것이다.
적당히 쪼개고 딱 두 줄만 추가했다.
private const EMAIL_REGEX = '/^'
. '(?!(?:(?:\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]+)*)'
. '|(?:[0-9]{3}\.){3}[0-9]{3}' // for test case 'email@123.123.123.123'
. '|\[(?:[0-9]{3}\.){3}[0-9]{3}\]' // for test case 'email@[123.123.123.123]'
. '|(?:\[(?:(?:(?:(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){7})|(?:(?!(?:.*[a-f0-9][:\]]){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})?)))'
. '|(?:(?:(?:(?:[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}))\]))'
. '$/iD';
이제 모든 테스트 케이스가 다 통과한다.
하지만 이걸로 끝일까?
IPv4, IPv6 도 검증 가능하도록 고치자
테스트 케이스는 통과하지만 추가한 두 줄을 잘 살펴보면 IP 주소를 제대로 표현하지 못한다는 것을 쉽게 알 수 있다.
그래서 IPv4 와 IPv6 를 표현할 수 있도록 다음과 같이 수정하였다.
private const IPV4_REGEX = '(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)';
private const IPV6_REGEX = '(?:(?:[A-F0-9]{1,4}:){7}[A-F0-9]{1,4}|(?=(?:[A-F0-9]{0,4}:){0,7}[A-F0-9]{0,4}$)(([0-9A-F]{1,4}:){1,7}|:)((:[0-9A-F]{1,4}){1,7}|:)|(?:[A-F0-9]{1,4}:){7}:|:(:[A-F0-9]{1,4}){7})';
// see: http://emailregex.com/
private const EMAIL_REGEX = '/^'
. '(?!(?:(?:\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]+)*)'
. '|' . self::IPV4_REGEX
. '|\[' . self::IPV4_REGEX . '\]'
. '|' . self::IPV6_REGEX
. '|\[' . self::IPV6_REGEX . '\]'
. '|(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)'
. '|\[(?:[0-9]{3}\.){3}[0-9]{3}\]' // for test case 'email@[123.123.123.123]'
. '|(?:\[(?:(?:(?:(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){7})|(?:(?!(?:.*[a-f0-9][:\]]){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})?)))'
. '|(?:(?:(?:(?:[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}))\]))'
. '$/iD';
위의 두 정규식은 한 권으로 끝내는 정규표현식(Regular Expressions Cookbook)을 참고해 옮긴 것이다.
그리고 다음은 IPv6 테스트까지 포함한 테스트 코드이다.
describe('isValidAddress', function() {
context('with valid email addresses', function(){
given('addresses', function () {
// see: https://blogs.msdn.microsoft.com/testing123/2009/02/06/email-address-test-cases/
return [
'email@domain.com' , // Valid email
'firstname.lastname@domain.com', // Email contains dot in the address field
'email@subdomain.domain.com', // Email contains dot with subdomain
'firstname+lastname@domain.com', // Plus sign is considered valid character
'email@123.123.123.123', // Domain is valid IP address
'email@127.0.0.1',
'email@[123.123.123.123]', // Square bracket around IP address is considered valid
'email@[127.0.0.1]',
'"email"@domain.com', // Quotes around email is considered valid
'1234567890@domain.com', // Digits in address are valid
'email@domain-one.com', // Dash in domain name is valid
'_______@domain.com', // Underscore in the address field is valid
'email@domain.name', // .name is valid Top Level Domain name
'email@domain.co.jp', // Dot in Top Level Domain name also considered valid (use co.jp as example here)
'firstname-lastname@domain.com', // Dash in address field is valid
'email@FE84:0000:0000:0000:1112:BBFF:AEFA:9999', // IPv6
'email@[FE84:0000:0000:0000:1112:BBFF:AEFA:9999]', // IPv6
];
});
it('returns true', function(){
foreach ($this->addresses as $address) {
expect($this->emailUtil->isValidAddress($address))->toBeTruthy();
}
});
});
context('with invalid email addresses', function(){
given('addresses', function () {
// see: https://blogs.msdn.microsoft.com/testing123/2009/02/06/email-address-test-cases/
return [
'',
' ',
'123',
'plainaddress', // Missing @ sign and domain
'#@%^%#$@#$@#.com', // Garbage
'@domain.com', // Missing username
'Joe Smith <email@domain.com>', // Encoded html within email is invalid
'email.domain.com', // Missing @
'email@domain@domain.com', // Two @ sign
'.email@domain.com', // Leading dot in address is not allowed
'email.@domain.com', // Trailing dot in address is not allowed
'email..email@domain.com', // Multiple dots
'あいうえお@domain.com', // Unicode char as address
'email@domain.com (Joe Smith)', // Text followed email is not allowed
'email@domain', // Missing top level domain (.com/.net/.org/etc)
'email@-domain.com', // Leading dash in front of domain is invalid
'email@111.222.333.44444', // Invalid IP format
'email@domain..com', // Multiple dot in the domain portion is invalid
];
});
it('returns false', function(){
foreach ($this->addresses as $address) {
expect($this->emailUtil->isValidAddress($address))->toBeFalsy();
}
});
});
php의 Filter 사용하기
FILTER_VALIDATE_EMAIL을 사용하면 위와 같이 복잡한 정규식을 사용하지 않아도 된다.- 이 필터는 RFC 822를 따른다고 한다.
- 단, 이 방법을 사용하면
@뒤쪽에 IPv4, IPv6 포맷의 도메인이 오는 경우를 검증하지 못한다.
public function isValidAddress(string $address): bool
{
return !empty($address) && filter_var($address, FILTER_VALIDATE_EMAIL);
}
Links
- RFC 4291 - IP Version 6 Addressing Architecture
- RFC 5321 - Simple Mail Transfer Protocol(SMTP)
- RFC 822 - Standard for ARPA Internet Text Messages
- emailregex.com
- Email Address test cases(MSDN)
- 한 권으로 끝내는 정규표현식(Regular Expressions Cookbook)
- php Validate filters