Files
urupam/lib/Urupam/Validation.pm

415 lines
12 KiB
Perl

package Urupam::Validation;
use Mojo::Base -base;
use Mojo::URL;
use Mojo::UserAgent;
use Mojo::Promise;
use Mojo::IOLoop;
use Urupam::Utils qw(sanitize_url);
use Socket
qw(getaddrinfo getnameinfo NI_NUMERICHOST NI_NUMERICSERV AF_INET AF_INET6 SOCK_STREAM);
my $MAX_URL_LENGTH = 2048;
my $CONNECT_TIMEOUT = 10;
my $REQUEST_TIMEOUT = 10;
my $MAX_REDIRECTS = 3;
my $DNS_ERROR_PATTERN =
qr/Name or service not known|getaddrinfo failed|Could not resolve|DNS|hostname|Name resolution|nodename nor servname provided/i;
my $SSL_ERROR_PATTERN = qr/SSL|certificate|TLS|verification failed/i;
my $CONNECTION_ERROR_PATTERN = qr/Connection refused|Can't connect|timeout/i;
my $PRIVATE_IP_PATTERN =
qr/^(127\.|192\.168\.|10\.|172\.(1[6-9]|2[0-9]|3[01])\.)/;
my @BLOCKED_DOMAINS = qw(
localhost 127.0.0.1 0.0.0.0 ::1
);
my $DNS_CACHE_TTL = 300;
my %dns_cache;
has ua => sub {
my $self = shift;
Mojo::UserAgent->new(
connect_timeout => $self->connect_timeout,
request_timeout => $self->request_timeout,
max_redirects => $self->max_redirects,
insecure => 0
);
};
has connect_timeout => sub { $CONNECT_TIMEOUT };
has request_timeout => sub { $REQUEST_TIMEOUT };
has max_redirects => sub { $MAX_REDIRECTS };
sub _parse_url {
my ( $self, $url ) = @_;
return undef unless defined $url;
my $parsed;
eval { $parsed = Mojo::URL->new($url); 1 } or return undef;
return $parsed;
}
sub _classify_error {
my ( $self, $err_str ) = @_;
return 'ssl' if $err_str =~ $SSL_ERROR_PATTERN;
return 'dns' if $err_str =~ $DNS_ERROR_PATTERN;
return 'connection' if $err_str =~ $CONNECTION_ERROR_PATTERN;
return 'unknown';
}
sub _format_error_message {
my ( $self, $error_type, $err_str ) = @_;
return "SSL certificate error: $err_str" if $error_type eq 'ssl';
return "DNS resolution failed: $err_str" if $error_type eq 'dns';
return "Cannot reach URL: $err_str" if $error_type eq 'connection';
return "URL validation failed: $err_str";
}
sub is_valid_url_length {
my ( $self, $url ) = @_;
return 0 unless defined $url && length($url) > 0;
return length($url) <= $MAX_URL_LENGTH;
}
sub _is_valid_ipv4 {
my ( $self, $ip ) = @_;
return 0 unless defined $ip;
return 0 unless $ip =~ /^(\d+)\.(\d+)\.(\d+)\.(\d+)$/;
my ( $a, $b, $c, $d ) = ( $1, $2, $3, $4 );
return
$a >= 0
&& $a <= 255
&& $b >= 0
&& $b <= 255
&& $c >= 0
&& $c <= 255
&& $d >= 0
&& $d <= 255;
}
sub _is_private_ipv4 {
my ( $self, $ip ) = @_;
return 0 unless $self->_is_valid_ipv4($ip);
return $ip =~ $PRIVATE_IP_PATTERN;
}
sub _is_private_ipv6 {
my ( $self, $ip ) = @_;
return 0 unless defined $ip;
$ip = lc($ip);
$ip =~ s/^\[|\]$//g;
return 1 if $ip eq '::1';
return 1 if $ip eq '::';
if ( $ip =~ /^::ffff:(.+)$/ ) {
return $self->_is_private_ipv4($1) ? 1 : 0;
}
return 0 unless $ip =~ /^([0-9a-f]{0,4}:)+[0-9a-f]{0,4}$/ || $ip =~ /^::/;
my @parts = split /:/, $ip;
return 0 unless @parts > 0;
my $first_part = $parts[0] || '';
return 0 unless length($first_part) > 0;
my $first = hex($first_part);
return 1 if ( $first & 0xfe00 ) == 0xfc00;
return 1 if ( $first & 0xffc0 ) == 0xfe80;
return 0;
}
sub _resolve_host {
my ( $self, $host ) = @_;
return Mojo::Promise->resolve( [] )
unless defined $host && length($host) > 0;
if ( $self->_is_valid_ipv4($host) ) {
return Mojo::Promise->resolve( [ { type => 'ipv4', ip => $host } ] );
}
my $ipv6_host = $host;
$ipv6_host =~ s/^\[|\]$//g;
if ( $self->_is_private_ipv6($ipv6_host) ) {
return Mojo::Promise->resolve(
[ { type => 'ipv6', ip => $ipv6_host } ] );
}
if ( $ipv6_host =~ /^([0-9a-f]{0,4}:){2,}[0-9a-f]{0,4}$/i
|| $ipv6_host =~ /^::/ )
{
return Mojo::Promise->resolve(
[ { type => 'ipv6', ip => $ipv6_host } ] );
}
my $cache_key = lc($host);
my $now = time();
if ( exists $dns_cache{$cache_key} ) {
my $cached = $dns_cache{$cache_key};
if ( $now < $cached->{expires} ) {
return Mojo::Promise->resolve( $cached->{addresses} );
}
delete $dns_cache{$cache_key};
}
my $promise = Mojo::Promise->new;
Mojo::IOLoop->subprocess(
sub {
my ($hostname) = @_;
my ( $err, @results ) =
getaddrinfo( $hostname, undef, { socktype => SOCK_STREAM } );
return { error => $err, results => \@results };
},
sub {
my ( $subprocess, $err, $data ) = @_;
if ($err) {
$promise->resolve( [] );
return;
}
my $res = $data;
if ( $res->{error} ) {
$promise->resolve( [] );
return;
}
my @addresses;
for my $result ( @{ $res->{results} } ) {
my ( $hostnum, undef ) =
getnameinfo( $result->{addr},
NI_NUMERICHOST | NI_NUMERICSERV );
next unless defined $hostnum && length $hostnum;
if ( $result->{family} == AF_INET ) {
push @addresses, { type => 'ipv4', ip => $hostnum };
}
elsif ( $result->{family} == AF_INET6 ) {
push @addresses, { type => 'ipv6', ip => $hostnum };
}
}
my $addresses_ref = \@addresses;
$dns_cache{$cache_key} = {
addresses => $addresses_ref,
expires => $now + $DNS_CACHE_TTL
};
$promise->resolve($addresses_ref);
},
$host
);
return $promise;
}
sub is_blocked_url {
my ( $self, $url ) = @_;
return Mojo::Promise->resolve(0) unless defined $url;
my $parsed = $self->_parse_url($url);
return Mojo::Promise->resolve(0) unless $parsed;
my $host = lc( $parsed->host // '' );
return Mojo::Promise->resolve(0) unless length($host) > 0;
for my $blocked (@BLOCKED_DOMAINS) {
return Mojo::Promise->resolve(1) if $host eq $blocked;
}
if ( $self->_is_private_ipv4($host) ) {
return Mojo::Promise->resolve(1);
}
if ( $self->_is_private_ipv6($host) ) {
return Mojo::Promise->resolve(1);
}
return $self->_resolve_host($host)->then(
sub {
my $addresses = shift;
for my $addr (@$addresses) {
if ( $addr->{type} eq 'ipv4'
&& $self->_is_private_ipv4( $addr->{ip} ) )
{
return 1;
}
if ( $addr->{type} eq 'ipv6'
&& $self->_is_private_ipv6( $addr->{ip} ) )
{
return 1;
}
}
return 0;
}
);
}
sub _create_ssrf_safe_ua {
my $self = shift;
return Mojo::UserAgent->new(
connect_timeout => $self->connect_timeout,
request_timeout => $self->request_timeout,
max_redirects => 0,
insecure => 0
);
}
sub _follow_redirect_with_validation {
my ( $self, $ua, $url, $redirect_count ) = @_;
$redirect_count //= 0;
return Mojo::Promise->reject('Too many redirects')
if $redirect_count > $self->max_redirects;
return $ua->head_p($url)->then(
sub {
my $tx = shift;
my $code = $tx->result->code;
if ( $code >= 300 && $code < 400 ) {
my $location = $tx->result->headers->location;
return Mojo::Promise->reject('Redirect without Location header')
unless defined $location;
my $redirect_url = Mojo::URL->new($location)->to_abs($url);
return $self->is_blocked_url($redirect_url)->then(
sub {
my $blocked = shift;
if ($blocked) {
return Mojo::Promise->reject(
'Redirect to blocked domain or local address');
}
return $self->_follow_redirect_with_validation( $ua,
$redirect_url, $redirect_count + 1 );
}
);
}
return 1 if $code >= 200 && $code < 400;
if ( $code == 403 || $code == 404 || $code == 405 ) {
return $ua->get_p($url)->then(
sub {
my $get_tx = shift;
my $get_code = $get_tx->result->code;
return 1 if $get_code >= 200 && $get_code < 400;
return 1
if $get_code == 403
|| $get_code == 404
|| $get_code == 405;
return Mojo::Promise->reject(
"URL returned $get_code error")
if $get_code >= 400;
return Mojo::Promise->reject(
"URL returned unexpected status: $get_code");
}
);
}
return Mojo::Promise->reject("URL returned $code error")
if $code >= 400;
return Mojo::Promise->reject(
"URL returned unexpected status: $code");
}
)->catch(
sub {
my $err = shift;
my $err_str = "$err";
my $error_type = $self->_classify_error($err_str);
return Mojo::Promise->reject(
$self->_format_error_message( $error_type, $err_str ) );
}
);
}
sub check_url_reachable {
my ( $self, $url ) = @_;
return Mojo::Promise->reject('URL is required')
unless defined $url && length($url) > 0;
my $ssrf_ua = $self->_create_ssrf_safe_ua;
return $self->_follow_redirect_with_validation( $ssrf_ua, $url );
}
sub check_ssl_certificate {
my ( $self, $url ) = @_;
return Mojo::Promise->reject('URL is required')
unless defined $url && length($url) > 0;
my $parsed = $self->_parse_url($url);
return Mojo::Promise->resolve(1)
unless $parsed && $parsed->scheme && $parsed->scheme eq 'https';
return $self->ua->head_p($url)->then( sub { return 1; } )->catch(
sub {
my $err = shift;
my $err_str = "$err";
my $error_type = $self->_classify_error($err_str);
if ( $error_type eq 'ssl' ) {
return Mojo::Promise->reject(
"Invalid SSL certificate: $err_str");
}
return Mojo::Promise->reject(
$self->_format_error_message( $error_type, $err_str ) );
}
);
}
sub validate_short_code {
my ( $self, $code ) = @_;
return defined $code && length($code) == 12 && $code =~ /^[0-9a-zA-Z\-_]+$/;
}
sub validate_url_with_checks {
my ( $self, $url ) = @_;
return Mojo::Promise->reject('URL is required')
unless defined $url && length($url) > 0;
my $sanitized = sanitize_url($url);
return Mojo::Promise->reject('Invalid URL format')
unless defined $sanitized;
my $parsed = $self->_parse_url($sanitized);
return Mojo::Promise->reject('Invalid URL format') unless $parsed;
return Mojo::Promise->reject('Invalid URL format')
unless $parsed->scheme && $parsed->scheme =~ /^https?$/i;
return Mojo::Promise->reject('Invalid URL format') unless $parsed->host;
my $normalized = $parsed->to_string;
return Mojo::Promise->reject(
"URL exceeds maximum length of $MAX_URL_LENGTH characters")
unless $self->is_valid_url_length($normalized);
return $self->is_blocked_url($normalized)->then(
sub {
my $blocked = shift;
return Mojo::Promise->reject(
'This URL cannot be shortened (blocked domain or local address)'
) if $blocked;
my $ssl_check =
$parsed->scheme eq 'https'
? $self->check_ssl_certificate($normalized)
: Mojo::Promise->resolve(1);
return $ssl_check->then(
sub { return $self->check_url_reachable($normalized); } )
->then( sub { return $normalized; } );
}
);
}
1;