mirror of https://github.com/M66B/FairEmail.git
M66B
4 years ago
parent
fd8cb3f68a
commit
eae08d5e29
File diff suppressed because it is too large
Load Diff
@ -0,0 +1,156 @@
|
||||
package eu.faircode.email;
|
||||
|
||||
/*
|
||||
This file is part of FairEmail.
|
||||
|
||||
FairEmail is free software: you can redistribute it and/or modify
|
||||
it under the terms of the GNU General Public License as published by
|
||||
the Free Software Foundation, either version 3 of the License, or
|
||||
(at your option) any later version.
|
||||
|
||||
FairEmail is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
GNU General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU General Public License
|
||||
along with FairEmail. If not, see <http://www.gnu.org/licenses/>.
|
||||
|
||||
Copyright 2018-2021 by Marcel Bokhorst (M66B)
|
||||
*/
|
||||
|
||||
import android.text.TextUtils;
|
||||
|
||||
import java.net.Inet4Address;
|
||||
import java.net.Inet6Address;
|
||||
import java.net.InetAddress;
|
||||
import java.net.UnknownHostException;
|
||||
import java.util.Date;
|
||||
import java.util.Hashtable;
|
||||
import java.util.Map;
|
||||
|
||||
public class DnsBlockList {
|
||||
// https://www.spamhaus.org/zen/
|
||||
static String[] DEFAULT_BLOCKLISTS = new String[]{"zen.spamhaus.org"};
|
||||
private static final long CACHE_EXPIRY_AFTER = 3600 * 1000L; // milliseconds
|
||||
private static final Map<InetAddress, CacheEntry> cache = new Hashtable<>();
|
||||
|
||||
static boolean isJunk(String email) {
|
||||
return isJunk(email, DEFAULT_BLOCKLISTS);
|
||||
}
|
||||
|
||||
static boolean isJunk(String email, String[] blocklists) {
|
||||
if (TextUtils.isEmpty(email))
|
||||
return false;
|
||||
int at = email.indexOf('@');
|
||||
if (at < 0)
|
||||
return false;
|
||||
String domain = email.substring(at + 1);
|
||||
for (String blocklist : blocklists)
|
||||
if (isJunk(domain, blocklist))
|
||||
return true;
|
||||
return false;
|
||||
}
|
||||
|
||||
private static boolean isJunk(String domain, String blocklist) {
|
||||
boolean blocked = false;
|
||||
try {
|
||||
for (InetAddress addr : InetAddress.getAllByName(domain))
|
||||
try {
|
||||
synchronized (cache) {
|
||||
CacheEntry cached = cache.get(addr);
|
||||
if (cached != null && !cached.isExpired())
|
||||
return cached.isJunk();
|
||||
}
|
||||
|
||||
StringBuilder lookup = new StringBuilder();
|
||||
if (addr instanceof Inet4Address) {
|
||||
byte[] a = addr.getAddress();
|
||||
for (int i = 3; i >= 0; i--)
|
||||
lookup.append(a[i] & 0xff).append('.');
|
||||
} else if (addr instanceof Inet6Address) {
|
||||
byte[] a = addr.getAddress();
|
||||
for (int i = 15; i >= 0; i--) {
|
||||
int b = a[i] & 0xff;
|
||||
lookup.append(String.format("%01x", b & 0xf)).append('.');
|
||||
lookup.append(String.format("%01x", b >> 4)).append('.');
|
||||
}
|
||||
}
|
||||
|
||||
lookup.append(blocklist);
|
||||
|
||||
InetAddress result;
|
||||
try {
|
||||
result = InetAddress.getByName(lookup.toString());
|
||||
if (result instanceof Inet4Address) {
|
||||
/*
|
||||
https://www.spamhaus.org/faq/section/DNSBL%20Usage#200
|
||||
|
||||
127.0.0.2 SBL Spamhaus SBL Data
|
||||
127.0.0.3 SBL Spamhaus SBL CSS Data
|
||||
127.0.0.4 XBL CBL Data
|
||||
127.0.0.9 SBL Spamhaus DROP/EDROP Data (in addition to 127.0.0.2, since 01-Jun-2016)
|
||||
127.0.0.10 PBL ISP Maintained
|
||||
127.0.0.11 PBL Spamhaus Maintained
|
||||
*/
|
||||
|
||||
byte[] a = result.getAddress();
|
||||
int statusClass = a[1] & 0xFF;
|
||||
int statusCode = a[3] & 0xFF;
|
||||
if (statusClass != 0 ||
|
||||
(statusCode != 2 &&
|
||||
statusCode != 3 &&
|
||||
statusCode != 4 &&
|
||||
statusCode != 9)) {
|
||||
Log.w("isJunk" +
|
||||
" addr=" + addr +
|
||||
" lookup=" + lookup +
|
||||
" result=" + result +
|
||||
" status=" + statusClass + "/" + statusCode);
|
||||
result = null;
|
||||
}
|
||||
} else {
|
||||
Log.w("isJunk result=" + result);
|
||||
result = null;
|
||||
}
|
||||
} catch (UnknownHostException ignored) {
|
||||
// Not blocked
|
||||
result = null;
|
||||
}
|
||||
|
||||
Log.i("isJunk " + addr + " " + lookup + "=" + (result == null ? "false" : result));
|
||||
|
||||
synchronized (cache) {
|
||||
cache.put(addr, new CacheEntry(result));
|
||||
}
|
||||
|
||||
if (result != null)
|
||||
blocked = true;
|
||||
} catch (Throwable ex) {
|
||||
Log.w(ex);
|
||||
}
|
||||
} catch (Throwable ex) {
|
||||
Log.w(ex);
|
||||
}
|
||||
|
||||
return blocked;
|
||||
}
|
||||
|
||||
private static class CacheEntry {
|
||||
private final long time;
|
||||
private final InetAddress result;
|
||||
|
||||
CacheEntry(InetAddress result) {
|
||||
this.time = new Date().getTime();
|
||||
this.result = result;
|
||||
}
|
||||
|
||||
boolean isExpired() {
|
||||
return (new Date().getTime() - this.time) > CACHE_EXPIRY_AFTER;
|
||||
}
|
||||
|
||||
boolean isJunk() {
|
||||
return (this.result != null);
|
||||
}
|
||||
}
|
||||
}
|
||||
Loading…
Reference in new issue