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/*
* Copyright (C) 2012-2014 Dominik Schürmann <dominik@dominikschuermann.de>
* Copyright (C) 2010-2014 Thialfihar <thi@thialfihar.org>
*
* This program 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.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.sufficientlysecure.keychain.pgp;
import android.net.Uri;
import org.openintents.openpgp.OpenPgpSignatureResult;
import org.spongycastle.bcpg.ArmoredInputStream;
import org.spongycastle.bcpg.SignatureSubpacketTags;
import org.spongycastle.openpgp.PGPCompressedData;
import org.spongycastle.openpgp.PGPEncryptedData;
import org.spongycastle.openpgp.PGPEncryptedDataList;
import org.spongycastle.openpgp.PGPException;
import org.spongycastle.openpgp.PGPLiteralData;
import org.spongycastle.openpgp.PGPObjectFactory;
import org.spongycastle.openpgp.PGPOnePassSignature;
import org.spongycastle.openpgp.PGPOnePassSignatureList;
import org.spongycastle.openpgp.PGPPBEEncryptedData;
import org.spongycastle.openpgp.PGPPrivateKey;
import org.spongycastle.openpgp.PGPPublicKey;
import org.spongycastle.openpgp.PGPPublicKeyEncryptedData;
import org.spongycastle.openpgp.PGPPublicKeyRing;
import org.spongycastle.openpgp.PGPSecretKey;
import org.spongycastle.openpgp.PGPSecretKeyRing;
import org.spongycastle.openpgp.PGPSignature;
import org.spongycastle.openpgp.PGPSignatureList;
import org.spongycastle.openpgp.PGPSignatureSubpacketVector;
import org.spongycastle.openpgp.PGPUtil;
import org.spongycastle.openpgp.operator.PBEDataDecryptorFactory;
import org.spongycastle.openpgp.operator.PBESecretKeyDecryptor;
import org.spongycastle.openpgp.operator.PGPDigestCalculatorProvider;
import org.spongycastle.openpgp.operator.PublicKeyDataDecryptorFactory;
import org.spongycastle.openpgp.operator.jcajce.JcaPGPContentVerifierBuilderProvider;
import org.spongycastle.openpgp.operator.jcajce.JcaPGPDigestCalculatorProviderBuilder;
import org.spongycastle.openpgp.operator.jcajce.JcePBEDataDecryptorFactoryBuilder;
import org.spongycastle.openpgp.operator.jcajce.JcePBESecretKeyDecryptorBuilder;
import org.spongycastle.openpgp.operator.jcajce.JcePublicKeyDataDecryptorFactoryBuilder;
import org.sufficientlysecure.keychain.Constants;
import org.sufficientlysecure.keychain.R;
import org.sufficientlysecure.keychain.pgp.exception.PgpGeneralException;
import org.sufficientlysecure.keychain.provider.KeychainContract.KeyRings;
import org.sufficientlysecure.keychain.provider.ProviderHelper;
import org.sufficientlysecure.keychain.util.InputData;
import org.sufficientlysecure.keychain.util.Log;
import org.sufficientlysecure.keychain.util.ProgressDialogUpdater;
import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.SignatureException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;
/**
* This class uses a Builder pattern!
*/
public class PgpDecryptVerify {
private ProviderHelper mProviderHelper;
private PassphraseCache mPassphraseCache;
private InputData mData;
private OutputStream mOutStream;
private ProgressDialogUpdater mProgressDialogUpdater;
private boolean mAllowSymmetricDecryption;
private String mPassphrase;
private Set<Long> mAllowedKeyIds;
private PgpDecryptVerify(Builder builder) {
// private Constructor can only be called from Builder
this.mProviderHelper = builder.mProviderHelper;
this.mPassphraseCache = builder.mPassphraseCache;
this.mData = builder.mData;
this.mOutStream = builder.mOutStream;
this.mProgressDialogUpdater = builder.mProgressDialogUpdater;
this.mAllowSymmetricDecryption = builder.mAllowSymmetricDecryption;
this.mPassphrase = builder.mPassphrase;
this.mAllowedKeyIds = builder.mAllowedKeyIds;
}
public static class Builder {
// mandatory parameter
private ProviderHelper mProviderHelper;
private PassphraseCache mPassphraseCache;
private InputData mData;
private OutputStream mOutStream;
// optional
private ProgressDialogUpdater mProgressDialogUpdater = null;
private boolean mAllowSymmetricDecryption = true;
private String mPassphrase = null;
private Set<Long> mAllowedKeyIds = null;
public Builder(ProviderHelper providerHelper, PassphraseCache passphraseCache,
InputData data, OutputStream outStream) {
this.mProviderHelper = providerHelper;
this.mPassphraseCache = passphraseCache;
this.mData = data;
this.mOutStream = outStream;
}
public Builder progressDialogUpdater(ProgressDialogUpdater progressDialogUpdater) {
this.mProgressDialogUpdater = progressDialogUpdater;
return this;
}
public Builder allowSymmetricDecryption(boolean allowSymmetricDecryption) {
this.mAllowSymmetricDecryption = allowSymmetricDecryption;
return this;
}
public Builder passphrase(String passphrase) {
this.mPassphrase = passphrase;
return this;
}
/**
* Allow these key ids alone for decryption.
* This means only ciphertexts encrypted for one of these private key can be decrypted.
*
* @param allowedKeyIds
* @return
*/
public Builder allowedKeyIds(Set<Long> allowedKeyIds) {
this.mAllowedKeyIds = allowedKeyIds;
return this;
}
public PgpDecryptVerify build() {
return new PgpDecryptVerify(this);
}
}
public void updateProgress(int message, int current, int total) {
if (mProgressDialogUpdater != null) {
mProgressDialogUpdater.setProgress(message, current, total);
}
}
public void updateProgress(int current, int total) {
if (mProgressDialogUpdater != null) {
mProgressDialogUpdater.setProgress(current, total);
}
}
public interface PassphraseCache {
public String getCachedPassphrase(long masterKeyId);
}
public static class InvalidDataException extends Exception {
public InvalidDataException() {
}
}
public static class KeyExtractionException extends Exception {
public KeyExtractionException() {
}
}
public static class WrongPassphraseException extends Exception {
public WrongPassphraseException() {
}
}
public static class NoSecretKeyException extends Exception {
public NoSecretKeyException() {
}
}
public static class IntegrityCheckFailedException extends Exception {
public IntegrityCheckFailedException() {
}
}
/**
* Decrypts and/or verifies data based on parameters of class
*
* @return
* @throws IOException
* @throws PgpGeneralException
* @throws PGPException
* @throws SignatureException
*/
public PgpDecryptVerifyResult execute()
throws IOException, PgpGeneralException, PGPException, SignatureException,
WrongPassphraseException, NoSecretKeyException, KeyExtractionException,
InvalidDataException, IntegrityCheckFailedException {
// automatically works with ascii armor input and binary
InputStream in = PGPUtil.getDecoderStream(mData.getInputStream());
if (in instanceof ArmoredInputStream) {
ArmoredInputStream aIn = (ArmoredInputStream) in;
// it is ascii armored
Log.d(Constants.TAG, "ASCII Armor Header Line: " + aIn.getArmorHeaderLine());
if (aIn.isClearText()) {
// a cleartext signature, verify it with the other method
return verifyCleartextSignature(aIn);
}
// else: ascii armored encryption! go on...
}
return decryptVerify(in);
}
/**
* Decrypt and/or verifies binary or ascii armored pgp
*
* @param in
* @return
* @throws IOException
* @throws PgpGeneralException
* @throws PGPException
* @throws SignatureException
*/
private PgpDecryptVerifyResult decryptVerify(InputStream in)
throws IOException, PgpGeneralException, PGPException, SignatureException,
WrongPassphraseException, KeyExtractionException, NoSecretKeyException,
InvalidDataException, IntegrityCheckFailedException {
PgpDecryptVerifyResult result = new PgpDecryptVerifyResult();
PGPObjectFactory pgpF = new PGPObjectFactory(in);
PGPEncryptedDataList enc;
Object o = pgpF.nextObject();
int currentProgress = 0;
updateProgress(R.string.progress_reading_data, currentProgress, 100);
if (o instanceof PGPEncryptedDataList) {
enc = (PGPEncryptedDataList) o;
} else {
enc = (PGPEncryptedDataList) pgpF.nextObject();
}
if (enc == null) {
// throw new PgpGeneralException(mContext.getString(R.string.error_invalid_data));
throw new InvalidDataException();
}
InputStream clear;
PGPEncryptedData encryptedData;
currentProgress += 5;
PGPPublicKeyEncryptedData encryptedDataAsymmetric = null;
PGPPBEEncryptedData encryptedDataSymmetric = null;
PGPSecretKey secretKey = null;
Iterator<?> it = enc.getEncryptedDataObjects();
boolean asymmetricPacketFound = false;
boolean symmetricPacketFound = false;
// find secret key
while (it.hasNext()) {
Object obj = it.next();
if (obj instanceof PGPPublicKeyEncryptedData) {
updateProgress(R.string.progress_finding_key, currentProgress, 100);
PGPPublicKeyEncryptedData encData = (PGPPublicKeyEncryptedData) obj;
long masterKeyId = 0;
PGPSecretKeyRing secretKeyRing = null;
try {
// get master key id for this encryption key id
masterKeyId = mProviderHelper.getMasterKeyId(
KeyRings.buildUnifiedKeyRingsFindBySubkeyUri(Long.toString(encData.getKeyID()))
);
// get actual keyring object based on master key id
secretKeyRing = mProviderHelper.getPGPSecretKeyRing(masterKeyId);
} catch (ProviderHelper.NotFoundException e) {
// continue with the next packet in the while loop
continue;
}
if (secretKeyRing == null) {
// continue with the next packet in the while loop
continue;
}
secretKey = secretKeyRing.getSecretKey(encData.getKeyID());
if (secretKey == null) {
// continue with the next packet in the while loop
continue;
}
/* secret key exists in database! */
// allow only a specific key for decryption?
if (mAllowedKeyIds != null) {
Log.d(Constants.TAG, "encData.getKeyID():" + encData.getKeyID());
Log.d(Constants.TAG, "allowedKeyIds: " + mAllowedKeyIds);
Log.d(Constants.TAG, "masterKeyId: " + masterKeyId);
if (!mAllowedKeyIds.contains(masterKeyId)) {
// this key is in our db, but NOT allowed!
// continue with the next packet in the while loop
continue;
}
}
/* secret key exists in database and is allowed! */
asymmetricPacketFound = true;
encryptedDataAsymmetric = encData;
// if no passphrase was explicitly set try to get it from the cache service
if (mPassphrase == null) {
// returns "" if key has no passphrase
mPassphrase = mPassphraseCache.getCachedPassphrase(masterKeyId);
// mPassphrase =
// PassphraseCacheService.getCachedPassphrase(mContext, masterKeyId);
// if passphrase was not cached, return here
// indicating that a passphrase is missing!
if (mPassphrase == null) {
result.setKeyIdPassphraseNeeded(masterKeyId);
result.setStatus(PgpDecryptVerifyResult.KEY_PASSHRASE_NEEDED);
return result;
}
}
// break out of while, only decrypt the first packet where we have a key
// TODO???: There could be more pgp objects, which are not decrypted!
break;
} else if (mAllowSymmetricDecryption && obj instanceof PGPPBEEncryptedData) {
/*
* When mAllowSymmetricDecryption == true and we find a data packet here,
* we do not search for other available asymmetric packets!
*/
symmetricPacketFound = true;
encryptedDataSymmetric = (PGPPBEEncryptedData) obj;
// if no passphrase is given, return here
// indicating that a passphrase is missing!
if (mPassphrase == null) {
result.setStatus(PgpDecryptVerifyResult.SYMMETRIC_PASSHRASE_NEEDED);
return result;
}
// break out of while, only decrypt the first packet
// TODO???: There could be more pgp objects, which are not decrypted!
break;
}
}
if (symmetricPacketFound) {
updateProgress(R.string.progress_preparing_streams, currentProgress, 100);
PGPDigestCalculatorProvider digestCalcProvider = new JcaPGPDigestCalculatorProviderBuilder()
.setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME).build();
PBEDataDecryptorFactory decryptorFactory = new JcePBEDataDecryptorFactoryBuilder(
digestCalcProvider).setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME).build(
mPassphrase.toCharArray());
clear = encryptedDataSymmetric.getDataStream(decryptorFactory);
encryptedData = encryptedDataSymmetric;
currentProgress += 5;
} else if (asymmetricPacketFound) {
currentProgress += 5;
updateProgress(R.string.progress_extracting_key, currentProgress, 100);
PGPPrivateKey privateKey;
try {
PBESecretKeyDecryptor keyDecryptor = new JcePBESecretKeyDecryptorBuilder()
.setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME).build(
mPassphrase.toCharArray());
privateKey = secretKey.extractPrivateKey(keyDecryptor);
} catch (PGPException e) {
// throw new PGPException(mContext.getString(R.string.error_wrong_passphrase));
throw new WrongPassphraseException();
}
if (privateKey == null) {
// throw new PgpGeneralException(
// mContext.getString(R.string.error_could_not_extract_private_key));
throw new KeyExtractionException();
}
currentProgress += 5;
updateProgress(R.string.progress_preparing_streams, currentProgress, 100);
PublicKeyDataDecryptorFactory decryptorFactory = new JcePublicKeyDataDecryptorFactoryBuilder()
.setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME).build(privateKey);
clear = encryptedDataAsymmetric.getDataStream(decryptorFactory);
encryptedData = encryptedDataAsymmetric;
currentProgress += 5;
} else {
// no packet has been found where we have the corresponding secret key in our db
// throw new PgpGeneralException(mContext.getString(R.string.error_no_secret_key_found));
throw new NoSecretKeyException();
}
PGPObjectFactory plainFact = new PGPObjectFactory(clear);
Object dataChunk = plainFact.nextObject();
PGPOnePassSignature signature = null;
OpenPgpSignatureResult signatureResult = null;
PGPPublicKey signatureKey = null;
int signatureIndex = -1;
if (dataChunk instanceof PGPCompressedData) {
updateProgress(R.string.progress_decompressing_data, currentProgress, 100);
PGPObjectFactory fact = new PGPObjectFactory(
((PGPCompressedData) dataChunk).getDataStream());
dataChunk = fact.nextObject();
plainFact = fact;
currentProgress += 10;
}
if (dataChunk instanceof PGPOnePassSignatureList) {
updateProgress(R.string.progress_processing_signature, currentProgress, 100);
signatureResult = new OpenPgpSignatureResult();
PGPOnePassSignatureList sigList = (PGPOnePassSignatureList) dataChunk;
Long masterKeyId = null;
for (int i = 0; i < sigList.size(); ++i) {
try {
Uri uri = KeyRings.buildUnifiedKeyRingsFindBySubkeyUri(
Long.toString(sigList.get(i).getKeyID()));
masterKeyId = mProviderHelper.getMasterKeyId(uri);
signatureIndex = i;
} catch (ProviderHelper.NotFoundException e) {
Log.d(Constants.TAG, "key not found!");
}
}
if (masterKeyId == null) {
try {
signatureKey = mProviderHelper
.getPGPPublicKeyRing(masterKeyId).getPublicKey();
} catch (ProviderHelper.NotFoundException e) {
// can't happen
}
signature = sigList.get(signatureIndex);
signatureResult.setUserId(PgpKeyHelper.getMainUserId(signatureKey));
signatureResult.setKeyId(signature.getKeyID());
JcaPGPContentVerifierBuilderProvider contentVerifierBuilderProvider =
new JcaPGPContentVerifierBuilderProvider()
.setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME);
signature.init(contentVerifierBuilderProvider, signatureKey);
} else {
if (!sigList.isEmpty()) {
signatureResult.setKeyId(sigList.get(0).getKeyID());
}
Log.d(Constants.TAG, "SIGNATURE_UNKNOWN_PUB_KEY");
signatureResult.setStatus(OpenPgpSignatureResult.SIGNATURE_UNKNOWN_PUB_KEY);
}
dataChunk = plainFact.nextObject();
currentProgress += 10;
}
if (dataChunk instanceof PGPSignatureList) {
dataChunk = plainFact.nextObject();
}
if (dataChunk instanceof PGPLiteralData) {
updateProgress(R.string.progress_decrypting, currentProgress, 100);
PGPLiteralData literalData = (PGPLiteralData) dataChunk;
byte[] buffer = new byte[1 << 16];
InputStream dataIn = literalData.getInputStream();
int startProgress = currentProgress;
int endProgress = 100;
if (signature != null) {
endProgress = 90;
} else if (encryptedData.isIntegrityProtected()) {
endProgress = 95;
}
int n;
// TODO: progress calculation is broken here! Try to rework it based on commented code!
// int progress = 0;
long startPos = mData.getStreamPosition();
while ((n = dataIn.read(buffer)) > 0) {
mOutStream.write(buffer, 0, n);
// progress += n;
if (signature != null) {
try {
signature.update(buffer, 0, n);
} catch (SignatureException e) {
Log.d(Constants.TAG, "SIGNATURE_ERROR");
signatureResult.setStatus(OpenPgpSignatureResult.SIGNATURE_ERROR);
signature = null;
}
}
// TODO: dead code?!
// unknown size, but try to at least have a moving, slowing down progress bar
// currentProgress = startProgress + (endProgress - startProgress) * progress
// / (progress + 100000);
if (mData.getSize() - startPos == 0) {
currentProgress = endProgress;
} else {
currentProgress = (int) (startProgress + (endProgress - startProgress)
* (mData.getStreamPosition() - startPos) / (mData.getSize() - startPos));
}
updateProgress(currentProgress, 100);
}
if (signature != null) {
updateProgress(R.string.progress_verifying_signature, 90, 100);
PGPSignatureList signatureList = (PGPSignatureList) plainFact.nextObject();
PGPSignature messageSignature = signatureList.get(signatureIndex);
// these are not cleartext signatures!
// TODO: what about binary signatures?
signatureResult.setSignatureOnly(false);
//Now check binding signatures
boolean validKeyBinding = verifyKeyBinding(messageSignature, signatureKey);
boolean validSignature = signature.verify(messageSignature);
// TODO: implement CERTIFIED!
if (validKeyBinding && validSignature) {
Log.d(Constants.TAG, "SIGNATURE_SUCCESS_UNCERTIFIED");
signatureResult.setStatus(OpenPgpSignatureResult.SIGNATURE_SUCCESS_UNCERTIFIED);
} else {
signatureResult.setStatus(OpenPgpSignatureResult.SIGNATURE_ERROR);
Log.e(Constants.TAG, "Error!\nvalidKeyBinding: " + validKeyBinding
+ "\nvalidSignature: " + validSignature);
}
}
}
if (encryptedData.isIntegrityProtected()) {
updateProgress(R.string.progress_verifying_integrity, 95, 100);
if (encryptedData.verify()) {
// passed
Log.d(Constants.TAG, "Integrity verification: success!");
} else {
// failed
Log.d(Constants.TAG, "Integrity verification: failed!");
// throw new PgpGeneralException(mContext.getString(R.string.error_integrity_check_failed));
throw new IntegrityCheckFailedException();
}
} else {
// no integrity check
Log.e(Constants.TAG, "Encrypted data was not integrity protected!");
// TODO: inform user?
}
updateProgress(R.string.progress_done, 100, 100);
result.setSignatureResult(signatureResult);
return result;
}
/**
* This method verifies cleartext signatures
* as defined in http://tools.ietf.org/html/rfc4880#section-7
* <p/>
* The method is heavily based on
* pg/src/main/java/org/spongycastle/openpgp/examples/ClearSignedFileProcessor.java
*
* @return
* @throws IOException
* @throws PgpGeneralException
* @throws PGPException
* @throws SignatureException
*/
private PgpDecryptVerifyResult verifyCleartextSignature(ArmoredInputStream aIn)
throws IOException, PgpGeneralException, PGPException, SignatureException, InvalidDataException {
PgpDecryptVerifyResult result = new PgpDecryptVerifyResult();
OpenPgpSignatureResult signatureResult = new OpenPgpSignatureResult();
// cleartext signatures are never encrypted ;)
signatureResult.setSignatureOnly(true);
ByteArrayOutputStream out = new ByteArrayOutputStream();
updateProgress(R.string.progress_done, 0, 100);
ByteArrayOutputStream lineOut = new ByteArrayOutputStream();
int lookAhead = readInputLine(lineOut, aIn);
byte[] lineSep = getLineSeparator();
byte[] line = lineOut.toByteArray();
out.write(line, 0, getLengthWithoutSeparator(line));
out.write(lineSep);
while (lookAhead != -1 && aIn.isClearText()) {
lookAhead = readInputLine(lineOut, lookAhead, aIn);
line = lineOut.toByteArray();
out.write(line, 0, getLengthWithoutSeparator(line));
out.write(lineSep);
}
out.close();
byte[] clearText = out.toByteArray();
mOutStream.write(clearText);
updateProgress(R.string.progress_processing_signature, 60, 100);
PGPObjectFactory pgpFact = new PGPObjectFactory(aIn);
PGPSignatureList sigList = (PGPSignatureList) pgpFact.nextObject();
if (sigList == null) {
// throw new PgpGeneralException(mContext.getString(R.string.error_corrupt_data));
throw new InvalidDataException();
}
PGPSignature signature = null;
long signatureKeyId = 0;
PGPPublicKey signatureKey = null;
for (int i = 0; i < sigList.size(); ++i) {
signature = sigList.get(i);
signatureKeyId = signature.getKeyID();
// find data about this subkey
HashMap<String, Object> data = mProviderHelper.getGenericData(
KeyRings.buildUnifiedKeyRingsFindBySubkeyUri(Long.toString(signature.getKeyID())),
new String[]{KeyRings.MASTER_KEY_ID, KeyRings.USER_ID},
new int[]{ProviderHelper.FIELD_TYPE_INTEGER, ProviderHelper.FIELD_TYPE_STRING});
// any luck? otherwise, try next.
if (data.get(KeyRings.MASTER_KEY_ID) == null) {
signature = null;
// do NOT reset signatureMasterKeyId, that one is shown when no known one is found!
continue;
}
// this one can't fail now (yay database constraints)
try {
signatureKey = mProviderHelper.getPGPPublicKeyRing((Long) data.get(KeyRings.MASTER_KEY_ID)).getPublicKey();
} catch (ProviderHelper.NotFoundException e) {
Log.e(Constants.TAG, "key not found!", e);
}
signatureResult.setUserId((String) data.get(KeyRings.USER_ID));
break;
}
signatureResult.setKeyId(signatureKeyId);
if (signature == null) {
Log.d(Constants.TAG, "SIGNATURE_UNKNOWN_PUB_KEY");
signatureResult.setStatus(OpenPgpSignatureResult.SIGNATURE_UNKNOWN_PUB_KEY);
result.setSignatureResult(signatureResult);
updateProgress(R.string.progress_done, 100, 100);
return result;
}
JcaPGPContentVerifierBuilderProvider contentVerifierBuilderProvider =
new JcaPGPContentVerifierBuilderProvider()
.setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME);
signature.init(contentVerifierBuilderProvider, signatureKey);
InputStream sigIn = new BufferedInputStream(new ByteArrayInputStream(clearText));
lookAhead = readInputLine(lineOut, sigIn);
processLine(signature, lineOut.toByteArray());
if (lookAhead != -1) {
do {
lookAhead = readInputLine(lineOut, lookAhead, sigIn);
signature.update((byte) '\r');
signature.update((byte) '\n');
processLine(signature, lineOut.toByteArray());
} while (lookAhead != -1);
}
//Now check binding signatures
boolean validKeyBinding = verifyKeyBinding(signature, signatureKey);
boolean validSignature = signature.verify();
if (validKeyBinding && validSignature) {
Log.d(Constants.TAG, "SIGNATURE_SUCCESS_UNCERTIFIED");
signatureResult.setStatus(OpenPgpSignatureResult.SIGNATURE_SUCCESS_UNCERTIFIED);
} else {
signatureResult.setStatus(OpenPgpSignatureResult.SIGNATURE_ERROR);
Log.e(Constants.TAG, "Error!\nvalidKeyBinding: " + validKeyBinding
+ "\nvalidSignature: " + validSignature);
}
// TODO: what about SIGNATURE_SUCCESS_CERTIFIED and SIGNATURE_ERROR????
result.setSignatureResult(signatureResult);
updateProgress(R.string.progress_done, 100, 100);
return result;
}
private boolean verifyKeyBinding(PGPSignature signature, PGPPublicKey signatureKey) {
long signatureKeyId = signature.getKeyID();
boolean validKeyBinding = false;
PGPPublicKey mKey = null;
try {
PGPPublicKeyRing signKeyRing = mProviderHelper.getPGPPublicKeyRingWithKeyId(
signatureKeyId);
mKey = signKeyRing.getPublicKey();
} catch (ProviderHelper.NotFoundException e) {
Log.d(Constants.TAG, "key not found");
}
if (signature.getKeyID() != mKey.getKeyID()) {
validKeyBinding = verifyKeyBinding(mKey, signatureKey);
} else { //if the key used to make the signature was the master key, no need to check binding sigs
validKeyBinding = true;
}
return validKeyBinding;
}
private boolean verifyKeyBinding(PGPPublicKey masterPublicKey, PGPPublicKey signingPublicKey) {
boolean validSubkeyBinding = false;
boolean validTempSubkeyBinding = false;
boolean validPrimaryKeyBinding = false;
JcaPGPContentVerifierBuilderProvider contentVerifierBuilderProvider =
new JcaPGPContentVerifierBuilderProvider()
.setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME);
Iterator<PGPSignature> itr = signingPublicKey.getSignatures();
while (itr.hasNext()) { //what does gpg do if the subkey binding is wrong?
//gpg has an invalid subkey binding error on key import I think, but doesn't shout
//about keys without subkey signing. Can't get it to import a slightly broken one
//either, so we will err on bad subkey binding here.
PGPSignature sig = itr.next();
if (sig.getKeyID() == masterPublicKey.getKeyID() &&
sig.getSignatureType() == PGPSignature.SUBKEY_BINDING) {
//check and if ok, check primary key binding.
try {
sig.init(contentVerifierBuilderProvider, masterPublicKey);
validTempSubkeyBinding = sig.verifyCertification(masterPublicKey, signingPublicKey);
} catch (PGPException e) {
continue;
} catch (SignatureException e) {
continue;
}
if (validTempSubkeyBinding) {
validSubkeyBinding = true;
}
if (validTempSubkeyBinding) {
validPrimaryKeyBinding = verifyPrimaryKeyBinding(sig.getUnhashedSubPackets(),
masterPublicKey, signingPublicKey);
if (validPrimaryKeyBinding) {
break;
}
validPrimaryKeyBinding = verifyPrimaryKeyBinding(sig.getHashedSubPackets(),
masterPublicKey, signingPublicKey);
if (validPrimaryKeyBinding) {
break;
}
}
}
}
return (validSubkeyBinding & validPrimaryKeyBinding);
}
private boolean verifyPrimaryKeyBinding(PGPSignatureSubpacketVector pkts,
PGPPublicKey masterPublicKey,
PGPPublicKey signingPublicKey) {
boolean validPrimaryKeyBinding = false;
JcaPGPContentVerifierBuilderProvider contentVerifierBuilderProvider =
new JcaPGPContentVerifierBuilderProvider()
.setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME);
PGPSignatureList eSigList;
if (pkts.hasSubpacket(SignatureSubpacketTags.EMBEDDED_SIGNATURE)) {
try {
eSigList = pkts.getEmbeddedSignatures();
} catch (IOException e) {
return false;
} catch (PGPException e) {
return false;
}
for (int j = 0; j < eSigList.size(); ++j) {
PGPSignature emSig = eSigList.get(j);
if (emSig.getSignatureType() == PGPSignature.PRIMARYKEY_BINDING) {
try {
emSig.init(contentVerifierBuilderProvider, signingPublicKey);
validPrimaryKeyBinding = emSig.verifyCertification(masterPublicKey, signingPublicKey);
if (validPrimaryKeyBinding) {
break;
}
} catch (PGPException e) {
continue;
} catch (SignatureException e) {
continue;
}
}
}
}
return validPrimaryKeyBinding;
}
/**
* Mostly taken from ClearSignedFileProcessor in Bouncy Castle
*
* @param sig
* @param line
* @throws SignatureException
*/
private static void processLine(PGPSignature sig, byte[] line)
throws SignatureException {
int length = getLengthWithoutWhiteSpace(line);
if (length > 0) {
sig.update(line, 0, length);
}
}
private static int readInputLine(ByteArrayOutputStream bOut, InputStream fIn)
throws IOException {
bOut.reset();
int lookAhead = -1;
int ch;
while ((ch = fIn.read()) >= 0) {
bOut.write(ch);
if (ch == '\r' || ch == '\n') {
lookAhead = readPassedEOL(bOut, ch, fIn);
break;
}
}
return lookAhead;
}
private static int readInputLine(ByteArrayOutputStream bOut, int lookAhead, InputStream fIn)
throws IOException {
bOut.reset();
int ch = lookAhead;
do {
bOut.write(ch);
if (ch == '\r' || ch == '\n') {
lookAhead = readPassedEOL(bOut, ch, fIn);
break;
}
} while ((ch = fIn.read()) >= 0);
if (ch < 0) {
lookAhead = -1;
}
return lookAhead;
}
private static int readPassedEOL(ByteArrayOutputStream bOut, int lastCh, InputStream fIn)
throws IOException {
int lookAhead = fIn.read();
if (lastCh == '\r' && lookAhead == '\n') {
bOut.write(lookAhead);
lookAhead = fIn.read();
}
return lookAhead;
}
private static int getLengthWithoutSeparator(byte[] line) {
int end = line.length - 1;
while (end >= 0 && isLineEnding(line[end])) {
end--;
}
return end + 1;
}
private static boolean isLineEnding(byte b) {
return b == '\r' || b == '\n';
}
private static int getLengthWithoutWhiteSpace(byte[] line) {
int end = line.length - 1;
while (end >= 0 && isWhiteSpace(line[end])) {
end--;
}
return end + 1;
}
private static boolean isWhiteSpace(byte b) {
return b == '\r' || b == '\n' || b == '\t' || b == ' ';
}
private static byte[] getLineSeparator() {
String nl = System.getProperty("line.separator");
byte[] nlBytes = new byte[nl.length()];
for (int i = 0; i != nlBytes.length; i++) {
nlBytes[i] = (byte) nl.charAt(i);
}
return nlBytes;
}
}
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