diff options
Diffstat (limited to 'OpenKeychain/src/main/java')
| -rw-r--r-- | OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/NfcIntentActivity.java | 312 | ||||
| -rw-r--r-- | OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/Iso7816TLV.java | 195 |
2 files changed, 507 insertions, 0 deletions
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/NfcIntentActivity.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/NfcIntentActivity.java new file mode 100644 index 000000000..cb15dbec2 --- /dev/null +++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/NfcIntentActivity.java @@ -0,0 +1,312 @@ +/** + * Copyright (c) 2013-2014 Philipp Jakubeit, Signe Rüsch, Dominik Schürmann + * + * Licensed under the Bouncy Castle License (MIT license). See LICENSE file for details. + */ + +package org.sufficientlysecure.keychain.ui; + +import android.annotation.TargetApi; +import android.app.PendingIntent; +import android.content.Intent; +import android.content.IntentFilter; +import android.nfc.NfcAdapter; +import android.nfc.Tag; +import android.nfc.tech.IsoDep; +import android.os.Build; +import android.os.Bundle; +import android.support.v7.app.ActionBarActivity; +import android.view.WindowManager; +import android.widget.Toast; + +import org.spongycastle.util.encoders.Hex; +import org.sufficientlysecure.keychain.Constants; +import org.sufficientlysecure.keychain.R; +import org.sufficientlysecure.keychain.util.Iso7816TLV; +import org.sufficientlysecure.keychain.ui.util.KeyFormattingUtils; +import org.sufficientlysecure.keychain.util.Log; + +import java.io.IOException; +import java.nio.ByteBuffer; + +/** + * This class provides a communication interface to OpenPGP applications on ISO SmartCard compliant + * NFC devices. + * + * For the full specs, see http://g10code.com/docs/openpgp-card-2.0.pdf + */ +@TargetApi(Build.VERSION_CODES.GINGERBREAD_MR1) +public class NfcIntentActivity extends ActionBarActivity { + + // special extra for OpenPgpService + public static final String EXTRA_DATA = "data"; + + private Intent mServiceIntent; + + private static final int TIMEOUT = 100000; + + private NfcAdapter mNfcAdapter; + + @Override + protected void onCreate(Bundle savedInstanceState) { + super.onCreate(savedInstanceState); + Log.d(Constants.TAG, "NfcActivity.onCreate"); + + getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); + + setContentView(R.layout.nfc_activity); + + Intent intent = getIntent(); + Bundle data = intent.getExtras(); + String action = intent.getAction(); + + Log.d(Constants.TAG, action); + Log.d(Constants.TAG, intent.getDataString()); + + // TODO check fingerprint + // mFingerprint = data.getByteArray(EXTRA_FINGERPRINT); + + if (!NfcAdapter.ACTION_NDEF_DISCOVERED.equals(action)) { + Log.d(Constants.TAG, "Action not supported: " + action); + finish(); + } + + try { + Tag detectedTag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG); + + // Connect to the detected tag, setting a couple of settings + IsoDep isoDep = IsoDep.get(detectedTag); + isoDep.setTimeout(TIMEOUT); // timeout is set to 100 seconds to avoid cancellation during calculation + isoDep.connect(); + + nfcGreet(isoDep); + // nfcPin(isoDep, "yoloswag"); + nfcGetFingerprint(isoDep); + + } catch (IOException e) { + Log.e(Constants.TAG, "IOException!", e); + finish(); + } + + } + + /** + * Called when the system is about to start resuming a previous activity, + * disables NFC Foreground Dispatch + */ + public void onPause() { + super.onPause(); + Log.d(Constants.TAG, "NfcActivity.onPause"); + + // disableNfcForegroundDispatch(); + } + + /** + * Called when the activity will start interacting with the user, + * enables NFC Foreground Dispatch + */ + public void onResume() { + super.onResume(); + Log.d(Constants.TAG, "NfcActivity.onResume"); + + // enableNfcForegroundDispatch(); + } + + /** Handle NFC communication and return a result. + * + * This method is called by onNewIntent above upon discovery of an NFC tag. + * It handles initialization and login to the application, subsequently + * calls either nfcCalculateSignature() or nfcDecryptSessionKey(), then + * finishes the activity with an appropiate result. + * + * On general communication, see also + * http://www.cardwerk.com/smartcards/smartcard_standard_ISO7816-4_annex-a.aspx + * + * References to pages are generally related to the OpenPGP Application + * on ISO SmartCard Systems specification. + * + */ + private void nfcGreet(IsoDep isoDep) throws IOException { + + // SW1/2 0x9000 is the generic "ok" response, which we expect most of the time. + // See specification, page 51 + String accepted = "9000"; + + // Command APDU (page 51) for SELECT FILE command (page 29) + String opening = + "00" // CLA + + "A4" // INS + + "04" // P1 + + "00" // P2 + + "06" // Lc (number of bytes) + + "D27600012401" // Data (6 bytes) + + "00"; // Le + if (!card(isoDep, opening).equals(accepted)) { // activate connection + toast("Opening Error!"); + setResult(RESULT_CANCELED, mServiceIntent); + finish(); + } + } + + private void nfcPin(IsoDep isoDep, String pin) throws IOException { + + String data = "00CA006E00"; + String fingerprint = card(isoDep, data); + + // Command APDU for VERIFY command (page 32) + String login = + "00" // CLA + + "20" // INS + + "00" // P1 + + "82" // P2 (PW1) + + String.format("%02x", pin.length()) // Lc + + Hex.toHexString(pin.getBytes()); + if ( ! card(isoDep, login).equals("9000")) { // login + toast("Pin Error!"); + setResult(RESULT_CANCELED, mServiceIntent); + finish(); + } + + } + + /** + * Gets the user ID + * + * @return the user id as "name <email>" + * @throws java.io.IOException + */ + public static String getUserId(IsoDep isoDep) throws IOException { + String info = "00CA006500"; + String data = "00CA005E00"; + return getName(card(isoDep, info)) + " <" + (new String(Hex.decode(getDataField(card(isoDep, data))))) + ">"; + } + + /** + * Gets the long key ID + * + * @return the long key id (last 16 bytes of the fingerprint) + * @throws java.io.IOException + */ + public static long getKeyId(IsoDep isoDep) throws IOException { + String keyId = nfcGetFingerprint(isoDep).substring(24); + Log.d(Constants.TAG, "keyId: " + keyId); + return Long.parseLong(keyId, 16); + } + + /** + * Gets the fingerprint of the signature key + * + * @return the fingerprint + * @throws java.io.IOException + */ + public static String nfcGetFingerprint(IsoDep isoDep) throws IOException { + String data = "00CA006E00"; + byte[] buf = isoDep.transceive(Hex.decode(data)); + + Iso7816TLV tlv = Iso7816TLV.readSingle(buf, true); + Log.d(Constants.TAG, "nfc tlv data:\n" + tlv.prettyPrint()); + + Iso7816TLV fptlv = Iso7816TLV.findRecursive(tlv, 0xc5); + if (fptlv != null) { + ByteBuffer fpbuf = ByteBuffer.wrap(fptlv.mV); + byte[] fp = new byte[20]; + fpbuf.get(fp); + Log.d(Constants.TAG, "fingerprint 1: " + KeyFormattingUtils.convertFingerprintToHex(fp)); + fpbuf.get(fp); + Log.d(Constants.TAG, "fingerprint 2: " + KeyFormattingUtils.convertFingerprintToHex(fp)); + fpbuf.get(fp); + Log.d(Constants.TAG, "fingerprint 3: " + KeyFormattingUtils.convertFingerprintToHex(fp)); + } + + return "nope"; + } + + /** + * Prints a message to the screen + * + * @param text the text which should be contained within the toast + */ + private void toast(String text) { + Toast.makeText(this, text, Toast.LENGTH_LONG).show(); + } + + /** + * Receive new NFC Intents to this activity only by enabling foreground dispatch. + * This can only be done in onResume! + */ + public void enableNfcForegroundDispatch() { + mNfcAdapter = NfcAdapter.getDefaultAdapter(this); + Intent nfcI = new Intent(this, NfcIntentActivity.class) + .addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP | Intent.FLAG_ACTIVITY_CLEAR_TOP); + PendingIntent nfcPendingIntent = PendingIntent.getActivity(this, 0, nfcI, 0); + IntentFilter[] writeTagFilters = new IntentFilter[]{ + new IntentFilter(NfcAdapter.ACTION_TAG_DISCOVERED) + }; + + // https://code.google.com/p/android/issues/detail?id=62918 + // maybe mNfcAdapter.enableReaderMode(); ? + try { + mNfcAdapter.enableForegroundDispatch(this, nfcPendingIntent, writeTagFilters, null); + } catch (IllegalStateException e) { + Log.i(Constants.TAG, "NfcForegroundDispatch Error!", e); + } + Log.d(Constants.TAG, "NfcForegroundDispatch has been enabled!"); + } + + /** + * Disable foreground dispatch in onPause! + */ + public void disableNfcForegroundDispatch() { + mNfcAdapter.disableForegroundDispatch(this); + Log.d(Constants.TAG, "NfcForegroundDispatch has been disabled!"); + } + + /** + * Gets the name of the user out of the raw card output regarding card holder related data + * + * @param name the raw card holder related data from the card + * @return the name given in this data + */ + public static String getName(String name) { + String slength; + int ilength; + name = name.substring(6); + slength = name.substring(0, 2); + ilength = Integer.parseInt(slength, 16) * 2; + name = name.substring(2, ilength + 2); + name = (new String(Hex.decode(name))).replace('<', ' '); + return (name); + } + + /** + * Reduces the raw data from the card by four characters + * + * @param output the raw data from the card + * @return the data field of that data + */ + private static String getDataField(String output) { + return output.substring(0, output.length() - 4); + } + + /** + * Communicates with the OpenPgpCard via the APDU + * + * @param hex the hexadecimal APDU + * @return The answer from the card + * @throws java.io.IOException throws an exception if something goes wrong + */ + public static String card(IsoDep isoDep, String hex) throws IOException { + return getHex(isoDep.transceive(Hex.decode(hex))); + } + + /** + * Converts a byte array into an hex string + * + * @param raw the byte array representation + * @return the hexadecimal string representation + */ + public static String getHex(byte[] raw) { + return new String(Hex.encode(raw)); + } + +} diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/Iso7816TLV.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/Iso7816TLV.java new file mode 100644 index 000000000..90afd3bc0 --- /dev/null +++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/Iso7816TLV.java @@ -0,0 +1,195 @@ +/* Copyright (C) 2014 Vincent Breitmoser <v.breitmoser@mugenguild.com> + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.sufficientlysecure.keychain.util; + +import java.io.IOException; +import java.nio.ByteBuffer; +import java.util.ArrayList; + +/** TLV data structure and parser implementation. + * + * This class is used for parsing and working with TLV packets as specified in + * the Functional Specification of the OpenPGP application on ISO Smart Card + * Operating Systems, and ISO 7816-4. + * + * Objects of this class are immutable data structs parsed from BER-TLV data. + * They include at least the T, L and V fields they were originally parsed + * from, subclasses may also carry more specific information. + * + * @see { @linktourl http://www.cardwerk.com/smartcards/smartcard_standard_ISO7816-4_annex-d.aspx} + * + */ +public class Iso7816TLV { + + public final int mT; + public final int mL; + public final byte[] mV; + + private Iso7816TLV(int T, int L, byte[] V) { + mT = T; + mL = L; + mV = V; + } + + public String prettyPrint() { + return prettyPrint(0); + } + + public String prettyPrint(int indent) { + // lol + String padding = " ".substring(0, indent*2); + return padding + String.format("tag T %4x L %04d", mT, mL); + } + + /** Read a single Iso7816 TLV packet from a given ByteBuffer, either + * recursively or flat. + * + * This is a convenience wrapper for readSingle with ByteBuffer argument. + */ + public static Iso7816TLV readSingle(byte[] data, boolean recursive) throws IOException { + return readSingle(ByteBuffer.wrap(data), recursive); + } + + /** Read a single Iso7816 TLV packet from a given ByteBuffer, either + * recursively or flat. + * + * If the recursive flag is true, a composite packet will be parsed and + * returned as an Iso7816CompositeTLV. Otherwise, a regular Iso7816TLV + * object will be returned regardless of actual packet type. + * + * This method is fail-fast, if any parsing error occurs it will throw an + * exception. + * + */ + public static Iso7816TLV readSingle(ByteBuffer data, boolean recursive) throws IOException { + + int T = data.get() & 0xff; + boolean composite = (T & 0x20) == 0x20; + if ((T & 0x1f) == 0x1f) { + int T2 = data.get() & 0xff; + if ((T2 & 0x1f) == 0x1f) { + throw new IOException("Only tags up to two bytes are supported!"); + } + T = (T << 8) | (T2 & 0x7f); + } + + // Log.d(Constants.TAG, String.format("T %02x", T)); + + // parse length, according to ISO 7816-4 (openpgp card 2.0 specs, page 24) + int L = data.get() & 0xff; + if (L == 0x81) { + L = data.get() & 0xff; + } else if (L == 0x82) { + L = data.get() & 0xff; + L = (L << 8) | (data.get() & 0xff); + } else if (L >= 0x80) { + throw new IOException("Invalid length field!"); + } + + // Log.d(Constants.TAG, String.format("L %02x", L)); + + // read L bytes into new buffer + byte[] V = new byte[L]; + data.get(V); + + // if we are supposed to parse composites, do that + if (recursive && composite) { + // Log.d(Constants.TAG, "parsing composite TLV"); + Iso7816TLV[] subs = readList(V, true); + return new Iso7816CompositeTLV(T, L, V, subs); + } + + return new Iso7816TLV(T, L, V); + + } + + /** Parse a list of TLV packets from byte data, recursively or flat. + * + * This method is fail-fast, if any parsing error occurs it will throw an + * exception. + * + */ + public static Iso7816TLV[] readList(byte[] data, boolean recursive) throws IOException { + ByteBuffer buf = ByteBuffer.wrap(data); + + ArrayList<Iso7816TLV> result = new ArrayList<Iso7816TLV>(); + + // read while data is available. this will fail if there is trailing data! + while (buf.hasRemaining()) { + // skip 0x00 and 0xFF filler bytes + buf.mark(); + byte peek = buf.get(); + if (peek == 0xff || peek == 0x00) { + continue; + } + buf.reset(); + + Iso7816TLV packet = readSingle(buf, recursive); + result.add(packet); + } + + Iso7816TLV[] resultX = new Iso7816TLV[result.size()]; + result.toArray(resultX); + return resultX; + } + + /** This class represents a composite TLV packet. + * + * Note that only actual composite TLV packets are instances of this class. + * A regular non-composite Iso7816TLV object may however be a composite + * packet if it was parsed non-recursively. + * + */ + public static class Iso7816CompositeTLV extends Iso7816TLV { + + public final Iso7816TLV[] mSubs; + + public Iso7816CompositeTLV(int T, int L, byte[] V, Iso7816TLV[] subs) { + super(T, L, V); + + mSubs = subs; + } + + public String prettyPrint(int indent) { + StringBuilder result = new StringBuilder(); + // lol + result.append(" ".substring(0, indent*2)); + result.append(String.format("composite tag T %4x L %04d", mT, mL)); + for (Iso7816TLV sub : mSubs) { + result.append('\n'); + result.append(sub.prettyPrint(indent+1)); + } + return result.toString(); + } + + } + + /** Recursively searches for a specific tag in a composite TLV packet structure, depth first. */ + public static Iso7816TLV findRecursive(Iso7816TLV in, int tag) { + if (in.mT == tag) { + return in; + } else if (in instanceof Iso7816CompositeTLV) { + for (Iso7816TLV sub : ((Iso7816CompositeTLV) in).mSubs) { + Iso7816TLV result = findRecursive(sub, tag); + if (result != null) { + return result; + } + } + } + return null; + } + +} |