From 76241e90ad440bedaf40f148ba0584e06064096a Mon Sep 17 00:00:00 2001 From: Joey Castillo Date: Wed, 6 May 2015 13:08:03 -0400 Subject: Adding NFC Key to Card operation, accessible from Edit Key activity. --- .../keychain/ui/base/BaseNfcActivity.java | 253 ++++++++++++++++++++- 1 file changed, 246 insertions(+), 7 deletions(-) (limited to 'OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/base/BaseNfcActivity.java') diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/base/BaseNfcActivity.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/base/BaseNfcActivity.java index 1d09b281f..4506fe3c1 100644 --- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/base/BaseNfcActivity.java +++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/base/BaseNfcActivity.java @@ -19,7 +19,9 @@ package org.sufficientlysecure.keychain.ui.base; import java.io.IOException; +import java.math.BigInteger; import java.nio.ByteBuffer; +import java.security.interfaces.RSAPrivateCrtKey; import android.app.Activity; import android.app.PendingIntent; @@ -32,9 +34,12 @@ import android.os.Bundle; import android.widget.Toast; import org.spongycastle.bcpg.HashAlgorithmTags; +import org.spongycastle.util.Arrays; import org.spongycastle.util.encoders.Hex; import org.sufficientlysecure.keychain.Constants; import org.sufficientlysecure.keychain.R; +import org.sufficientlysecure.keychain.pgp.CanonicalizedSecretKey; +import org.sufficientlysecure.keychain.pgp.exception.PgpGeneralException; import org.sufficientlysecure.keychain.pgp.exception.PgpKeyNotFoundException; import org.sufficientlysecure.keychain.provider.CachedPublicKeyRing; import org.sufficientlysecure.keychain.provider.KeychainContract.KeyRings; @@ -54,12 +59,16 @@ import org.sufficientlysecure.keychain.util.Preferences; public abstract class BaseNfcActivity extends BaseActivity { - public static final int REQUEST_CODE_PASSPHRASE = 1; + public static final int REQUEST_CODE_PIN = 1; + public static final int REQUEST_CODE_PASSPHRASE = 2; protected Passphrase mPin; + protected Passphrase mAdminPin; + protected Passphrase mPassphrase; // For key export protected boolean mPw1ValidForMultipleSignatures; protected boolean mPw1ValidatedForSignature; protected boolean mPw1ValidatedForDecrypt; // Mode 82 does other things; consider renaming? + protected boolean mPw3Validated; private NfcAdapter mNfcAdapter; private IsoDep mIsoDep; @@ -127,6 +136,15 @@ public abstract class BaseNfcActivity extends BaseActivity { enableNfcForegroundDispatch(); } + protected void obtainKeyExportPassphrase(RequiredInputParcel requiredInput) { + + Intent intent = new Intent(this, PassphraseDialogActivity.class); + intent.putExtra(PassphraseDialogActivity.EXTRA_REQUIRED_INPUT, + RequiredInputParcel.createRequiredPassphrase(requiredInput)); + startActivityForResult(intent, REQUEST_CODE_PASSPHRASE); + + } + protected void obtainYubiKeyPin(RequiredInputParcel requiredInput) { Preferences prefs = Preferences.getPreferences(this); @@ -138,7 +156,7 @@ public abstract class BaseNfcActivity extends BaseActivity { Intent intent = new Intent(this, PassphraseDialogActivity.class); intent.putExtra(PassphraseDialogActivity.EXTRA_REQUIRED_INPUT, RequiredInputParcel.createRequiredPassphrase(requiredInput)); - startActivityForResult(intent, REQUEST_CODE_PASSPHRASE); + startActivityForResult(intent, REQUEST_CODE_PIN); } @@ -149,7 +167,7 @@ public abstract class BaseNfcActivity extends BaseActivity { @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { switch (requestCode) { - case REQUEST_CODE_PASSPHRASE: + case REQUEST_CODE_PIN: { if (resultCode != Activity.RESULT_OK) { setResult(resultCode); finish(); @@ -158,6 +176,18 @@ public abstract class BaseNfcActivity extends BaseActivity { CryptoInputParcel input = data.getParcelableExtra(PassphraseDialogActivity.RESULT_CRYPTO_INPUT); mPin = input.getPassphrase(); break; + } + + case REQUEST_CODE_PASSPHRASE: { + if (resultCode != Activity.RESULT_OK) { + setResult(resultCode); + finish(); + return; + } + CryptoInputParcel input = data.getParcelableExtra(PassphraseDialogActivity.RESULT_CRYPTO_INPUT); + mPassphrase = input.getPassphrase(); + break; + } default: super.onActivityResult(requestCode, resultCode, data); @@ -208,6 +238,10 @@ public abstract class BaseNfcActivity extends BaseActivity { mPw1ValidForMultipleSignatures = (pwStatusBytes[0] == 1); mPw1ValidatedForSignature = false; mPw1ValidatedForDecrypt = false; + mPw3Validated = false; + + // TODO: Handle non-default Admin PIN + mAdminPin = new Passphrase("12345678"); onNfcPerform(); @@ -460,13 +494,21 @@ public abstract class BaseNfcActivity extends BaseActivity { return Hex.decode(decryptedSessionKey); } - /** Verifies the user's PW1 with the appropriate mode. + /** Verifies the user's PW1 or PW3 with the appropriate mode. * - * @param mode This is 0x81 for signing, 0x82 for everything else + * @param mode For PW1, this is 0x81 for signing, 0x82 for everything else. + * For PW3 (Admin PIN), mode is 0x83. */ public void nfcVerifyPIN(int mode) throws IOException { - if (mPin != null) { - byte[] pin = new String(mPin.getCharArray()).getBytes(); + if (mPin != null || mode == 0x83) { + byte[] pin; + + if (mode == 0x83) { + pin = new String(mAdminPin.getCharArray()).getBytes(); + } else { + pin = new String(mPin.getCharArray()).getBytes(); + } + // SW1/2 0x9000 is the generic "ok" response, which we expect most of the time. // See specification, page 51 String accepted = "9000"; @@ -488,10 +530,207 @@ public abstract class BaseNfcActivity extends BaseActivity { mPw1ValidatedForSignature = true; } else if (mode == 0x82) { mPw1ValidatedForDecrypt = true; + } else if (mode == 0x83) { + mPw3Validated = true; } } } + /** Modifies the user's PW1 or PW3. Before sending, the new PIN will be validated for + * conformance to the card's requirements for key length. + * + * @param pw For PW1, this is 0x81. For PW3 (Admin PIN), mode is 0x83. + * @param newPinString The new PW1 or PW3. + */ + public void nfcModifyPIN(int pw, String newPinString) throws IOException { + final int MAX_PW1_LENGTH_INDEX = 1; + final int MAX_PW3_LENGTH_INDEX = 3; + + byte[] pwStatusBytes = nfcGetPwStatusBytes(); + byte[] newPin = newPinString.getBytes(); + + if (pw == 0x81) { + if (newPin.length < 6 || newPin.length > pwStatusBytes[MAX_PW1_LENGTH_INDEX]) { + throw new IOException("Invalid PIN length"); + } + } else if (pw == 0x83) { + if (newPin.length < 8 || newPin.length > pwStatusBytes[MAX_PW3_LENGTH_INDEX]) { + throw new IOException("Invalid PIN length"); + } + } else { + throw new IOException("Invalid PW index for modify PIN operation"); + } + + byte[] pin; + + if (pw == 0x83) { + pin = new String(mAdminPin.getCharArray()).getBytes(); + } else { + pin = new String(mPin.getCharArray()).getBytes(); + } + + // Command APDU for CHANGE REFERENCE DATA command (page 32) + String changeReferenceDataApdu = "00" // CLA + + "24" // INS + + "00" // P1 + + String.format("%02x", pw) // P2 + + String.format("%02x", pin.length + newPin.length) // Lc + + getHex(pin) + + getHex(newPin); + if (!nfcCommunicate(changeReferenceDataApdu).equals("9000")) { // Change reference data + handlePinError(); + throw new IOException("Failed to change PIN"); + } + } + + /** + * Stores a data object on the card. Automatically validates the proper PIN for the operation. + * Supported for all data objects < 255 bytes in length. Only the cardholder certificate + * (0x7F21) can exceed this length. + * + * @param dataObject The data object to be stored. + * @param data The data to store in the object + */ + public void nfcPutData(int dataObject, byte[] data) throws IOException { + if (data.length > 254) { + throw new IOException("Cannot PUT DATA with length > 254"); + } + if (dataObject == 0x0101 || dataObject == 0x0103) { + if (!mPw1ValidatedForDecrypt) { + nfcVerifyPIN(0x82); // (Verify PW1 for non-signing operations) + } + } else if (!mPw3Validated) { + nfcVerifyPIN(0x83); // (Verify PW3) + } + + String putDataApdu = "00" // CLA + + "DA" // INS + + String.format("%02x", (dataObject & 0xFF00) >> 8) // P1 + + String.format("%02x", dataObject & 0xFF) // P2 + + String.format("%02x", data.length) // Lc + + getHex(data); + + String response = nfcCommunicate(putDataApdu); + if (!response.equals("9000")) { + throw new IOException("Failed to put data for tag " + + String.format("%02x", (dataObject & 0xFF00) >> 8) + + String.format("%02x", dataObject & 0xFF) + + ": " + response); + } + } + + /** + * Puts a key on the card in the given slot. + * + * @param slot The slot on the card where the key should be stored: + * 0xB6: Signature Key + * 0xB8: Decipherment Key + * 0xA4: Authentication Key + */ + public void nfcPutKey(int slot, CanonicalizedSecretKey secretKey) + throws IOException { + if (slot != 0xB6 && slot != 0xB8 && slot != 0xA4) { + throw new IOException("Invalid key slot"); + } + + RSAPrivateCrtKey crtSecretKey = null; + try { + secretKey.unlock(mPassphrase); + crtSecretKey = secretKey.getCrtSecretKey(); + } catch (PgpGeneralException e) { + throw new IOException(e.getMessage()); + } + + // Shouldn't happen; the UI should block the user from getting an incompatible key this far. + if (crtSecretKey.getModulus().bitLength() > 2048) { + throw new IOException("Key too large to export to smart card."); + } + + // Should happen only rarely; all GnuPG keys since 2006 use public exponent 65537. + if (!crtSecretKey.getPublicExponent().equals(new BigInteger("65537"))) { + throw new IOException("Invalid public exponent for smart card key."); + } + + if (!mPw3Validated) { + nfcVerifyPIN(0x83); // (Verify PW1 with mode 83) + } + + byte[] header= Hex.decode( + "4D82" + "03A2" // Extended header list 4D82, length of 930 bytes. (page 23) + + String.format("%02x", slot) + "00" // CRT to indicate targeted key, no length + + "7F48" + "15" // Private key template 0x7F48, length 21 (decimal, 0x15 hex) + + "9103" // Public modulus, length 3 + + "928180" // Prime P, length 128 + + "938180" // Prime Q, length 128 + + "948180" // Coefficient (1/q mod p), length 128 + + "958180" // Prime exponent P (d mod (p - 1)), length 128 + + "968180" // Prime exponent Q (d mod (1 - 1)), length 128 + + "97820100" // Modulus, length 256, last item in private key template + + "5F48" + "820383");// DO 5F48; 899 bytes of concatenated key data will follow + byte[] dataToSend = new byte[934]; + byte[] currentKeyObject; + int offset = 0; + + System.arraycopy(header, 0, dataToSend, offset, header.length); + offset += header.length; + currentKeyObject = crtSecretKey.getPublicExponent().toByteArray(); + System.arraycopy(currentKeyObject, 0, dataToSend, offset, 3); + offset += 3; + // NOTE: For a 2048-bit key, these lengths are fixed. However, bigint includes a leading 0 + // in the array to represent sign, so we take care to set the offset to 1 if necessary. + currentKeyObject = crtSecretKey.getPrimeP().toByteArray(); + System.arraycopy(currentKeyObject, currentKeyObject.length - 128, dataToSend, offset, 128); + Arrays.fill(currentKeyObject, (byte)0); + offset += 128; + currentKeyObject = crtSecretKey.getPrimeQ().toByteArray(); + System.arraycopy(currentKeyObject, currentKeyObject.length - 128, dataToSend, offset, 128); + Arrays.fill(currentKeyObject, (byte)0); + offset += 128; + currentKeyObject = crtSecretKey.getCrtCoefficient().toByteArray(); + System.arraycopy(currentKeyObject, currentKeyObject.length - 128, dataToSend, offset, 128); + Arrays.fill(currentKeyObject, (byte)0); + offset += 128; + currentKeyObject = crtSecretKey.getPrimeExponentP().toByteArray(); + System.arraycopy(currentKeyObject, currentKeyObject.length - 128, dataToSend, offset, 128); + Arrays.fill(currentKeyObject, (byte)0); + offset += 128; + currentKeyObject = crtSecretKey.getPrimeExponentQ().toByteArray(); + System.arraycopy(currentKeyObject, currentKeyObject.length - 128, dataToSend, offset, 128); + Arrays.fill(currentKeyObject, (byte)0); + offset += 128; + currentKeyObject = crtSecretKey.getModulus().toByteArray(); + System.arraycopy(currentKeyObject, currentKeyObject.length - 256, dataToSend, offset, 256); + + String putKeyCommand = "10DB3FFF"; + String lastPutKeyCommand = "00DB3FFF"; + + // Now we're ready to communicate with the card. + offset = 0; + String response; + while(offset < dataToSend.length) { + int dataRemaining = dataToSend.length - offset; + if (dataRemaining > 254) { + response = nfcCommunicate( + putKeyCommand + "FE" + Hex.toHexString(dataToSend, offset, 254) + ); + offset += 254; + } else { + int length = dataToSend.length - offset; + response = nfcCommunicate( + lastPutKeyCommand + String.format("%02x", length) + + Hex.toHexString(dataToSend, offset, length)); + offset += length; + } + + if (!response.endsWith("9000")) { + throw new IOException("Key export to card failed"); + } + } + + // Clear array with secret data before we return. + Arrays.fill(dataToSend, (byte) 0); + } + /** * Prints a message to the screen * -- cgit v1.2.3