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Code Issues Releases Wiki Activity

FFSend implementation

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M66B 2022-07-31 14:11:13 +02:00
parent 895751cd91
commit 1660aa2e01
3 changed files with 252 additions and 0 deletions
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4
app/build.gradle
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@ -386,6 +386,7 @@ dependencies {
def compress_version = "1.21"
def ipaddress_version = "5.3.4"
def canary_version = "2.9.1"
def ws_version = "2.14"
// https://developer.android.com/jetpack/androidx/releases/startup
implementation "androidx.startup:startup-runtime:$startup_version"
@ -600,4 +601,7 @@ dependencies {
// https://square.github.io/leakcanary/getting_started/
// https://mvnrepository.com/artifact/com.squareup.leakcanary/leakcanary-android
debugImplementation "com.squareup.leakcanary:leakcanary-android:$canary_version"
// https://github.com/TakahikoKawasaki/nv-websocket-client
implementation "com.neovisionaries:nv-websocket-client:$ws_version"
}

8
app/src/dummy/java/eu/faircode/email/FFSend.java Normal file
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@ -0,0 +1,8 @@
package eu.faircode.email;
import java.io.File;
public class FFSend {
public static void upload(File file, int dLimit, int timeLimit, String uri) {
}
}

240
app/src/extra/java/eu/faircode/email/FFSend.java Normal file
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@ -0,0 +1,240 @@
package eu.faircode.email;
import android.util.Base64;
import com.neovisionaries.ws.client.WebSocket;
import com.neovisionaries.ws.client.WebSocketAdapter;
import com.neovisionaries.ws.client.WebSocketFactory;
import org.bouncycastle.crypto.digests.SHA256Digest;
import org.bouncycastle.crypto.generators.HKDFBytesGenerator;
import org.bouncycastle.crypto.params.HKDFParameters;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.GCMParameterSpec;
import javax.crypto.spec.SecretKeySpec;
public class FFSend {
// https://github.com/timvisee/send-instances/
// https://github.com/nneonneo/ffsend/blob/master/ffsend.py
// https://datatracker.ietf.org/doc/html/rfc8188
// wss://send.vis.ee/api/ws
/*
curl --request POST \
--url https://send.zcyph.cc/api/info/... \
--header 'Content-Type: application/json' \
--data '{"owner_token": "..."}'
*/
private static final int FF_TIMEOUT = 5000;
public static void upload(File file, int dLimit, int timeLimit, String uri) throws Throwable {
SecureRandom rnd = new SecureRandom();
byte[] secret = new byte[16];
rnd.nextBytes(secret);
JSONObject jupload = getMetadata(file, dLimit, timeLimit, secret);
WebSocket ws = new WebSocketFactory().createSocket(uri, FF_TIMEOUT);
Semaphore sem = new Semaphore(0);
List<String> queue = Collections.synchronizedList(new ArrayList<>());
ws.addListener(new WebSocketAdapter() {
@Override
public void onTextMessage(WebSocket ws, String text) throws Exception {
Log.i("FFSend text message=" + text);
queue.add(text);
sem.release();
}
});
Log.i("FFSend connect");
ws.connect();
try {
Log.i("FFSend upload=" + jupload);
ws.sendText(jupload.toString());
Log.i("FFSend wait reply");
sem.tryAcquire(FF_TIMEOUT, TimeUnit.MILLISECONDS);
JSONObject jreply = new JSONObject(queue.remove(0));
Log.i("FFSend reply=" + jreply);
Log.i("FFSend url=" + jreply.getString("url") +
"#" + Base64.encodeToString(secret, Base64.URL_SAFE | Base64.NO_PADDING | Base64.NO_WRAP));
// The record sequence number (SEQ) is a 96-bit unsigned integer in network byte order that starts at zero.
// network byte order = transmitting the most significant byte first
// Java = big endian = network byte order
// sizeof(int) = 4 bytes
int seq = 0;
byte[] buffer = new byte[65536];
byte[] salt = new byte[16];
rnd.nextBytes(salt);
// https://datatracker.ietf.org/doc/html/rfc8188#section-2.1
byte[] header = new byte[16 /* salt */ + 4 /* rs */ + 1 /* idlen */ + 0 /* keyid */];
ByteBuffer.wrap(header)
.put(salt)
.putInt(salt.length, buffer.length);
// idlen = 0
// keyid = ""
Log.i("FFSend header=" + Helper.hex(header));
ws.sendBinary(header);
// https://datatracker.ietf.org/doc/html/rfc8188#section-2.2
// cek_info = "Content-Encoding: aes128gcm" || 0x00
// CEK = HMAC-SHA-256(PRK, cek_info || 0x01)
// AEAD_AES_128_GCM requires a 16-octet (128-bit) content-encryption key (CEK),
// so the length (L) parameter to HKDF is 16
byte[] cek = new byte[16];
HKDFBytesGenerator hkdf = new HKDFBytesGenerator(new SHA256Digest());
hkdf.init(new HKDFParameters(secret /* ikm */, salt, "Content-Encoding: aes128gcm\0".getBytes()));
hkdf.generateBytes(cek /* okm */, 0, cek.length);
// nonce_info = "Content-Encoding: nonce" || 0x00
// NONCE = HMAC-SHA-256(PRK, nonce_info || 0x01) XOR SEQ
// The length (L) parameter is 12 octets.
byte[] nonce_base = new byte[12];
hkdf = new HKDFBytesGenerator(new SHA256Digest());
hkdf.init(new HKDFParameters(secret /* ikm */, salt, "Content-Encoding: nonce\0".getBytes()));
hkdf.generateBytes(nonce_base /* okm */, 0, nonce_base.length);
Log.i("FFSend nonce base=" + Helper.hex(nonce_base));
// TODO zero length files
try (InputStream is = new FileInputStream(file)) {
int len;
long size = 0;
long fileSize = file.length();
// content any length up to rs-17 octets
while ((len = is.read(buffer, 0, buffer.length - 17)) > 0) {
Log.i("FFSend read=" + len);
// add a delimiter octet (0x01 or 0x02)
// then 0x00-valued octets to rs-16 (or less on the last record)
// The last record uses a padding delimiter octet set to the value 2,
// all other records have a padding delimiter octet value of 1.
size += len;
if (size == fileSize)
buffer[len++] = 0x02;
else {
buffer[len++] = 0x01;
while (len < buffer.length - 17)
buffer[len++] = 0x00;
}
Log.i("FFSend record len=" + len + " size=" + size + "/" + fileSize);
byte[] nonce = Arrays.copyOf(nonce_base, nonce_base.length);
ByteBuffer xor = ByteBuffer.wrap(nonce);
xor.putInt(nonce.length - 4, xor.getInt(nonce.length - 4) ^ seq);
Log.i("FFSend seq=" + seq + " nonce=" + Helper.hex(nonce));
// encrypt with AEAD_AES_128_GCM; final size is rs; the last record can be smaller
Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
cipher.init(Cipher.ENCRYPT_MODE,
new SecretKeySpec(cek, "AES"),
new GCMParameterSpec(16 * 8, nonce));
byte[] message = cipher.doFinal(buffer, 0, len);
Log.i("FFSend message len=" + message.length);
ws.sendBinary(message);
seq++;
}
Log.i("FFSend EOF size=" + size);
ws.sendBinary(new byte[]{0}, true);
}
Log.i("FFSend wait confirm");
sem.tryAcquire(FF_TIMEOUT, TimeUnit.MILLISECONDS);
JSONObject jconfirm = new JSONObject(queue.remove(0));
Log.i("FFSend confirm=" + jconfirm);
if (!jconfirm.getBoolean("ok"))
throw new FileNotFoundException();
} finally {
ws.disconnect();
}
}
private static JSONObject getMetadata(File file, int dLimit, int timeLimit, byte[] secret)
throws JSONException, NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
String fileName = file.getName();
long fileSize = file.length();
String mimeType = Helper.guessMimeType(fileName);
JSONObject jfile = new JSONObject();
jfile.put("name", fileName);
jfile.put("size", fileSize);
jfile.put("type", mimeType);
JSONArray jfiles = new JSONArray();
jfiles.put(jfile);
JSONObject jmanifest = new JSONObject();
jmanifest.put("files", jfiles);
JSONObject jmeta = new JSONObject();
jmeta.put("name", fileName); // Shown on website
jmeta.put("size", fileSize);
jmeta.put("type", mimeType);
jmeta.put("manifest", jmanifest);
Log.i("FFSend meta=" + jmeta);
byte[] auth_key = new byte[64];
HKDFBytesGenerator hkdf = new HKDFBytesGenerator(new SHA256Digest());
hkdf.init(new HKDFParameters(secret /* ikm */, new byte[0] /* salt */, "authentication".getBytes()));
hkdf.generateBytes(auth_key /* okm */, 0, auth_key.length);
byte[] meta_key = new byte[16];
hkdf = new HKDFBytesGenerator(new SHA256Digest());
hkdf.init(new HKDFParameters(secret /* ikm */, new byte[0] /* salt */, "metadata".getBytes()));
hkdf.generateBytes(meta_key /* okm */, 0, meta_key.length);
Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
cipher.init(Cipher.ENCRYPT_MODE,
new SecretKeySpec(meta_key, "AES"),
new GCMParameterSpec(16 * 8, new byte[12]));
byte[] metadata = cipher.doFinal(jmeta.toString().getBytes());
JSONObject jupload = new JSONObject();
jupload.put("fileMetadata", Base64.encodeToString(metadata, Base64.URL_SAFE | Base64.NO_PADDING | Base64.NO_WRAP));
jupload.put("authorization", "send-v1 " + Base64.encodeToString(auth_key, Base64.URL_SAFE | Base64.NO_PADDING | Base64.NO_WRAP));
jupload.put("dlimit", dLimit);
jupload.put("timeLimit", timeLimit); // seconds
return jupload;
}
}