keepassgo/androidsrc/org/julianfamily/keepassgo/AutofillCacheStore.java

package org.julianfamily.keepassgo;

import android.content.Context;
import android.util.JsonReader;
import android.util.Log;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

final class AutofillCacheStore {
    private static final String TAG = "KeePassGOAutofill";

    private AutofillCacheStore() {
    }

    static Entry findBestMatch(Context context, String webDomain) {
        File cacheFile = findCacheFile(context);
        if (cacheFile == null) {
            Log.i(TAG, "autofill cache file not found");
            return null;
        }
        List<Entry> entries;
        try {
            entries = readEntries(cacheFile);
        } catch (IOException err) {
            Log.e(TAG, "failed to read autofill cache", err);
            return null;
        }
        if (entries.isEmpty()) {
            return null;
        }
        String normalizedDomain = normalizeHost(webDomain);
        if (normalizedDomain.isEmpty()) {
            return entries.get(0);
        }
        Entry fallback = null;
        for (Entry entry : entries) {
            if (entry.host.equals(normalizedDomain)) {
                return entry;
            }
            if (fallback == null && normalizedDomain.endsWith("." + entry.host)) {
                fallback = entry;
            }
        }
        return fallback;
    }

    private static File findCacheFile(Context context) {
        List<File> candidates = new ArrayList<>();
        File filesDir = context.getFilesDir();
        if (filesDir != null) {
            candidates.add(new File(filesDir, "keepassgo/autofill-cache.json"));
            candidates.add(new File(filesDir, ".config/keepassgo/autofill-cache.json"));
            candidates.add(new File(filesDir, "config/keepassgo/autofill-cache.json"));
        }
        File baseDir = context.getDataDir();
        if (baseDir != null) {
            candidates.add(new File(baseDir, "files/keepassgo/autofill-cache.json"));
            candidates.add(new File(baseDir, "files/.config/keepassgo/autofill-cache.json"));
            candidates.add(new File(baseDir, "files/config/keepassgo/autofill-cache.json"));
        }
        for (File candidate : candidates) {
            if (candidate.isFile()) {
                Log.i(TAG, "using autofill cache " + candidate.getAbsolutePath());
                return candidate;
            }
        }
        Log.i(TAG, "no autofill cache file in " + candidates);
        return null;
    }

    private static List<Entry> readEntries(File cacheFile) throws IOException {
        List<Entry> entries = new ArrayList<>();
        try (JsonReader reader = new JsonReader(new InputStreamReader(new FileInputStream(cacheFile), StandardCharsets.UTF_8))) {
            reader.beginObject();
            while (reader.hasNext()) {
                String name = reader.nextName();
                if ("entries".equals(name)) {
                    reader.beginArray();
                    while (reader.hasNext()) {
                        entries.add(readEntry(reader));
                    }
                    reader.endArray();
                } else {
                    reader.skipValue();
                }
            }
            reader.endObject();
        }
        return entries;
    }

    private static Entry readEntry(JsonReader reader) throws IOException {
        String title = "";
        String username = "";
        String password = "";
        String host = "";
        reader.beginObject();
        while (reader.hasNext()) {
            String name = reader.nextName();
            switch (name) {
                case "title":
                    title = nextString(reader);
                    break;
                case "username":
                    username = nextString(reader);
                    break;
                case "password":
                    password = nextString(reader);
                    break;
                case "host":
                    host = normalizeHost(nextString(reader));
                    break;
                default:
                    reader.skipValue();
                    break;
            }
        }
        reader.endObject();
        return new Entry(title, username, password, host);
    }

    private static String nextString(JsonReader reader) throws IOException {
        if (reader.peek() == android.util.JsonToken.NULL) {
            reader.nextNull();
            return "";
        }
        return reader.nextString();
    }

    private static String normalizeHost(String raw) {
        if (raw == null) {
            return "";
        }
        String value = raw.trim().toLowerCase(Locale.US);
        if (value.startsWith("http://")) {
            value = value.substring("http://".length());
        } else if (value.startsWith("https://")) {
            value = value.substring("https://".length());
        }
        int slash = value.indexOf('/');
        if (slash >= 0) {
            value = value.substring(0, slash);
        }
        int colon = value.indexOf(':');
        if (colon >= 0) {
            value = value.substring(0, colon);
        }
        return value;
    }

    static final class Entry {
        final String title;
        final String username;
        final String password;
        final String host;

        Entry(String title, String username, String password, String host) {
            this.title = title;
            this.username = username;
            this.password = password;
            this.host = host;
        }
    }
}