Java tutorial
/* * Copyright (C) 2012-2014 Dominik Schrmann <dominik@dominikschuermann.de> * Copyright (C) 2010-2014 Thialfihar <thi@thialfihar.org> * Copyright (C) 2015-2016 Vincent Breitmoser <look@my.amazin.horse> * * 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 java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.nio.ByteBuffer; import java.security.SignatureException; import java.util.Date; import java.util.Iterator; import java.util.Map; import java.util.Map.Entry; import android.content.Context; import android.support.annotation.NonNull; import android.text.TextUtils; import android.webkit.MimeTypeMap; import org.bouncycastle.bcpg.ArmoredInputStream; import org.bouncycastle.openpgp.PGPCompressedData; import org.bouncycastle.openpgp.PGPDataValidationException; import org.bouncycastle.openpgp.PGPEncryptedData; import org.bouncycastle.openpgp.PGPEncryptedDataList; import org.bouncycastle.openpgp.PGPException; import org.bouncycastle.openpgp.PGPKeyValidationException; import org.bouncycastle.openpgp.PGPLiteralData; import org.bouncycastle.openpgp.PGPPBEEncryptedData; import org.bouncycastle.openpgp.PGPPublicKeyEncryptedData; import org.bouncycastle.openpgp.PGPSignatureList; import org.bouncycastle.openpgp.PGPUtil; import org.bouncycastle.openpgp.jcajce.JcaSkipMarkerPGPObjectFactory; import org.bouncycastle.openpgp.operator.PBEDataDecryptorFactory; import org.bouncycastle.openpgp.operator.PGPDigestCalculatorProvider; import org.bouncycastle.openpgp.operator.jcajce.CachingDataDecryptorFactory; import org.bouncycastle.openpgp.operator.jcajce.JcaPGPDigestCalculatorProviderBuilder; import org.bouncycastle.openpgp.operator.jcajce.JcePBEDataDecryptorFactoryBuilder; import org.bouncycastle.util.encoders.DecoderException; import org.openintents.openpgp.OpenPgpDecryptionResult; import org.openintents.openpgp.OpenPgpMetadata; import org.sufficientlysecure.keychain.Constants; import org.sufficientlysecure.keychain.Constants.key; import org.sufficientlysecure.keychain.R; import org.sufficientlysecure.keychain.operations.BaseOperation; import org.sufficientlysecure.keychain.operations.results.DecryptVerifyResult; import org.sufficientlysecure.keychain.operations.results.OperationResult.LogType; import org.sufficientlysecure.keychain.operations.results.OperationResult.OperationLog; import org.sufficientlysecure.keychain.pgp.CanonicalizedSecretKey.SecretKeyType; 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; import org.sufficientlysecure.keychain.provider.ProviderHelper; import org.sufficientlysecure.keychain.service.input.CryptoInputParcel; import org.sufficientlysecure.keychain.service.input.RequiredInputParcel; import org.sufficientlysecure.keychain.ui.util.KeyFormattingUtils; import org.sufficientlysecure.keychain.util.CharsetVerifier; import org.sufficientlysecure.keychain.util.FileHelper; import org.sufficientlysecure.keychain.util.InputData; import org.sufficientlysecure.keychain.util.Log; import org.sufficientlysecure.keychain.util.Passphrase; import org.sufficientlysecure.keychain.util.ProgressScaler; public class PgpDecryptVerifyOperation extends BaseOperation<PgpDecryptVerifyInputParcel> { public static final int PROGRESS_STRIDE_MILLISECONDS = 200; public PgpDecryptVerifyOperation(Context context, ProviderHelper providerHelper, Progressable progressable) { super(context, providerHelper, progressable); } /** Decrypts and/or verifies data based on parameters of PgpDecryptVerifyInputParcel. */ @NonNull public DecryptVerifyResult execute(PgpDecryptVerifyInputParcel input, CryptoInputParcel cryptoInput) { InputData inputData; OutputStream outputStream; long startTime = System.currentTimeMillis(); if (input.getInputBytes() != null) { byte[] inputBytes = input.getInputBytes(); inputData = new InputData(new ByteArrayInputStream(inputBytes), inputBytes.length); } else { try { InputStream inputStream = mContext.getContentResolver().openInputStream(input.getInputUri()); long inputSize = FileHelper.getFileSize(mContext, input.getInputUri(), 0); inputData = new InputData(inputStream, inputSize); } catch (FileNotFoundException e) { Log.e(Constants.TAG, "Input URI could not be opened: " + input.getInputUri(), e); OperationLog log = new OperationLog(); log.add(LogType.MSG_DC_ERROR_INPUT, 1); return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log); } } if (input.getOutputUri() == null) { outputStream = new ByteArrayOutputStream(); } else { try { outputStream = mContext.getContentResolver().openOutputStream(input.getOutputUri()); } catch (FileNotFoundException e) { Log.e(Constants.TAG, "Output URI could not be opened: " + input.getOutputUri(), e); OperationLog log = new OperationLog(); log.add(LogType.MSG_DC_ERROR_IO, 1); return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log); } } DecryptVerifyResult result = executeInternal(input, cryptoInput, inputData, outputStream); if (outputStream instanceof ByteArrayOutputStream) { byte[] outputData = ((ByteArrayOutputStream) outputStream).toByteArray(); result.setOutputBytes(outputData); } result.mOperationTime = System.currentTimeMillis() - startTime; Log.d(Constants.TAG, "total time taken: " + String.format("%.2f", result.mOperationTime / 1000.0) + "s"); return result; } @NonNull public DecryptVerifyResult execute(PgpDecryptVerifyInputParcel input, CryptoInputParcel cryptoInput, InputData inputData, OutputStream outputStream) { return executeInternal(input, cryptoInput, inputData, outputStream); } @NonNull private DecryptVerifyResult executeInternal(PgpDecryptVerifyInputParcel input, CryptoInputParcel cryptoInput, InputData inputData, OutputStream outputStream) { try { if (input.getDetachedSignature() != null) { Log.d(Constants.TAG, "Detached signature present, verifying with this signature only"); return verifyDetachedSignature(input, inputData, outputStream, 0); } else { // automatically works with PGP ascii armor and PGP binary InputStream inputStream = PGPUtil.getDecoderStream(inputData.getInputStream()); if (inputStream instanceof ArmoredInputStream) { ArmoredInputStream aIn = (ArmoredInputStream) inputStream; // 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(input, aIn, outputStream, 0); } else { // else: ascii armored encryption! go on... return decryptVerify(input, cryptoInput, inputData, inputStream, outputStream, 0); } } else { return decryptVerify(input, cryptoInput, inputData, inputStream, outputStream, 0); } } } catch (PGPException e) { Log.d(Constants.TAG, "PGPException", e); OperationLog log = new OperationLog(); log.add(LogType.MSG_DC_ERROR_PGP_EXCEPTION, 1); return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log); } catch (DecoderException | ArrayIndexOutOfBoundsException e) { // these can happen if assumptions in JcaPGPObjectFactory.nextObject() aren't // fulfilled, so we need to catch them here to handle this gracefully Log.d(Constants.TAG, "data error", e); OperationLog log = new OperationLog(); log.add(LogType.MSG_DC_ERROR_IO, 1); return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log); } catch (IOException e) { Log.d(Constants.TAG, "IOException", e); OperationLog log = new OperationLog(); log.add(LogType.MSG_DC_ERROR_IO, 1); return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log); } } private static class EncryptStreamResult { // this is non-null iff an error occured, return directly DecryptVerifyResult errorResult; // for verification PGPEncryptedData encryptedData; InputStream cleartextStream; // the cached session key byte[] sessionKey; byte[] decryptedSessionKey; int symmetricEncryptionAlgo = 0; boolean skippedDisallowedKey = false; boolean insecureEncryptionKey = false; // convenience method to return with error public EncryptStreamResult with(DecryptVerifyResult result) { errorResult = result; return this; } } private static class ArmorHeaders { String charset = null; Integer backupVersion = null; } private ArmorHeaders parseArmorHeaders(InputStream in, OperationLog log, int indent) { ArmorHeaders armorHeaders = new ArmorHeaders(); // If the input stream is armored, and there is a charset specified, take a note for later // https://tools.ietf.org/html/rfc4880#page56 if (in instanceof ArmoredInputStream) { ArmoredInputStream aIn = (ArmoredInputStream) in; if (aIn.getArmorHeaders() != null) { for (String header : aIn.getArmorHeaders()) { String[] pieces = header.split(":", 2); if (pieces.length != 2 || TextUtils.isEmpty(pieces[0]) || TextUtils.isEmpty(pieces[1])) { continue; } switch (pieces[0].toLowerCase()) { case "charset": { armorHeaders.charset = pieces[1].trim(); break; } case "backupversion": { try { armorHeaders.backupVersion = Integer.valueOf(pieces[1].trim()); } catch (NumberFormatException e) { continue; } break; } default: { // continue; } } } if (armorHeaders.charset != null) { log.add(LogType.MSG_DC_CHARSET, indent, armorHeaders.charset); } if (armorHeaders.backupVersion != null) { log.add(LogType.MSG_DC_BACKUP_VERSION, indent, Integer.toString(armorHeaders.backupVersion)); } } } return armorHeaders; } /** Decrypt and/or verify binary or ascii armored pgp data. */ @NonNull private DecryptVerifyResult decryptVerify(PgpDecryptVerifyInputParcel input, CryptoInputParcel cryptoInput, InputData inputData, InputStream in, OutputStream out, int indent) throws IOException, PGPException { OperationLog log = new OperationLog(); log.add(LogType.MSG_DC, indent); indent += 1; updateProgress(R.string.progress_reading_data, 0, 100); // parse ASCII Armor headers ArmorHeaders armorHeaders = parseArmorHeaders(in, log, indent); String charset = armorHeaders.charset; boolean useBackupCode = false; if (armorHeaders.backupVersion != null && armorHeaders.backupVersion == 2) { useBackupCode = true; } OpenPgpDecryptionResultBuilder decryptionResultBuilder = new OpenPgpDecryptionResultBuilder(); JcaSkipMarkerPGPObjectFactory plainFact; Object dataChunk; EncryptStreamResult esResult = null; { // resolve encrypted (symmetric and asymmetric) packets JcaSkipMarkerPGPObjectFactory pgpF = new JcaSkipMarkerPGPObjectFactory(in); Object obj = pgpF.nextObject(); if (obj instanceof PGPEncryptedDataList) { esResult = handleEncryptedPacket(input, cryptoInput, (PGPEncryptedDataList) obj, log, indent, useBackupCode); // if there is an error, nothing left to do here if (esResult.errorResult != null) { return esResult.errorResult; } // if this worked out so far, the data is encrypted decryptionResultBuilder.setEncrypted(true); if (esResult.sessionKey != null && esResult.decryptedSessionKey != null) { decryptionResultBuilder.setSessionKey(esResult.sessionKey, esResult.decryptedSessionKey); } if (esResult.insecureEncryptionKey) { log.add(LogType.MSG_DC_INSECURE_SYMMETRIC_ENCRYPTION_ALGO, indent + 1); decryptionResultBuilder.setInsecure(true); } // Check for insecure encryption algorithms! if (!PgpSecurityConstants.isSecureSymmetricAlgorithm(esResult.symmetricEncryptionAlgo)) { log.add(LogType.MSG_DC_INSECURE_SYMMETRIC_ENCRYPTION_ALGO, indent + 1); decryptionResultBuilder.setInsecure(true); } plainFact = new JcaSkipMarkerPGPObjectFactory(esResult.cleartextStream); dataChunk = plainFact.nextObject(); } else { decryptionResultBuilder.setEncrypted(false); plainFact = pgpF; dataChunk = obj; } } log.add(LogType.MSG_DC_PREP_STREAMS, indent); log.add(LogType.MSG_DC_CLEAR, indent); indent += 1; // resolve compressed data if (dataChunk instanceof PGPCompressedData) { log.add(LogType.MSG_DC_CLEAR_DECOMPRESS, indent + 1); PGPCompressedData compressedData = (PGPCompressedData) dataChunk; JcaSkipMarkerPGPObjectFactory fact = new JcaSkipMarkerPGPObjectFactory(compressedData.getDataStream()); dataChunk = fact.nextObject(); plainFact = fact; } PgpSignatureChecker signatureChecker = new PgpSignatureChecker(mProviderHelper, input.getSenderAddress()); if (signatureChecker.initializeOnePassSignature(dataChunk, log, indent + 1)) { dataChunk = plainFact.nextObject(); } if (dataChunk instanceof PGPSignatureList) { // skip dataChunk = plainFact.nextObject(); } OpenPgpMetadata metadata; if (!(dataChunk instanceof PGPLiteralData)) { log.add(LogType.MSG_DC_ERROR_INVALID_DATA, indent); return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log); } log.add(LogType.MSG_DC_CLEAR_DATA, indent + 1); indent += 2; PGPLiteralData literalData = (PGPLiteralData) dataChunk; String originalFilename = literalData.getFileName(); // reject filenames with slashes completely (path traversal issue) if (originalFilename.contains("/")) { originalFilename = ""; } String mimeType = null; if (literalData.getFormat() == PGPLiteralData.TEXT || literalData.getFormat() == PGPLiteralData.UTF8) { mimeType = "text/plain"; } else { // try to guess from file ending String extension = MimeTypeMap.getFileExtensionFromUrl(originalFilename); if (extension != null) { MimeTypeMap mime = MimeTypeMap.getSingleton(); mimeType = mime.getMimeTypeFromExtension(extension); } } if (mimeType == null) { mimeType = "application/octet-stream"; } if (!"".equals(originalFilename)) { log.add(LogType.MSG_DC_CLEAR_META_FILE, indent + 1, originalFilename); } log.add(LogType.MSG_DC_CLEAR_META_TIME, indent + 1, new Date(literalData.getModificationTime().getTime()).toString()); // return here if we want to decrypt the metadata only if (input.isDecryptMetadataOnly()) { log.add(LogType.MSG_DC_CLEAR_META_MIME, indent + 1, mimeType); // this operation skips the entire stream to find the data length! Long originalSize = literalData.findDataLength(); if (originalSize != null) { log.add(LogType.MSG_DC_CLEAR_META_SIZE, indent + 1, Long.toString(originalSize)); } else { log.add(LogType.MSG_DC_CLEAR_META_SIZE_UNKNOWN, indent + 1); } metadata = new OpenPgpMetadata(originalFilename, mimeType, literalData.getModificationTime().getTime(), originalSize == null ? 0 : originalSize, charset); log.add(LogType.MSG_DC_OK_META_ONLY, indent); DecryptVerifyResult result = new DecryptVerifyResult(DecryptVerifyResult.RESULT_OK, log); result.setDecryptionMetadata(metadata); return result; } InputStream dataIn = literalData.getInputStream(); long opTime, startTime = System.currentTimeMillis(); long alreadyWritten = 0; long wholeSize = inputData.getSize() - inputData.getStreamPosition(); boolean sizeIsKnown = inputData.getSize() != InputData.UNKNOWN_FILESIZE && wholeSize > 0; int length; byte[] buffer = new byte[8192]; byte[] firstBytes = new byte[48]; CharsetVerifier charsetVerifier = new CharsetVerifier(buffer, mimeType, charset); updateProgress(R.string.progress_decrypting, 1, 100); long nextProgressTime = 0L; int lastReportedProgress = 1; while ((length = dataIn.read(buffer)) > 0) { // Log.d(Constants.TAG, "read bytes: " + length); if (out != null) { out.write(buffer, 0, length); } // update signature buffer if signature is also present signatureChecker.updateSignatureData(buffer, 0, length); charsetVerifier.readBytesFromBuffer(0, length); // note down first couple of bytes for "magic bytes" file type detection if (alreadyWritten == 0) { System.arraycopy(buffer, 0, firstBytes, 0, length > firstBytes.length ? firstBytes.length : length); } alreadyWritten += length; if (sizeIsKnown && nextProgressTime < System.currentTimeMillis()) { long progress = 100 * inputData.getStreamPosition() / wholeSize; // stop at 100% for wrong file sizes... if (progress > 100) { progress = 100; } if (progress > lastReportedProgress) { updateProgress((int) progress, 100); lastReportedProgress = (int) progress; nextProgressTime = System.currentTimeMillis() + PROGRESS_STRIDE_MILLISECONDS; } } } if (signatureChecker.isInitialized()) { Object o = plainFact.nextObject(); boolean signatureCheckOk = signatureChecker.verifySignatureOnePass(o, log, indent + 1); if (!signatureCheckOk) { return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log); } } opTime = System.currentTimeMillis() - startTime; Log.d(Constants.TAG, "decrypt time taken: " + String.format("%.2f", opTime / 1000.0) + "s, for " + alreadyWritten + " bytes"); // special treatment to detect pgp mime types // TODO move into CharsetVerifier? seems like that would be a plausible place for this logic if (matchesPrefix(firstBytes, "-----BEGIN PGP PUBLIC KEY BLOCK-----") || matchesPrefix(firstBytes, "-----BEGIN PGP PRIVATE KEY BLOCK-----")) { mimeType = Constants.MIME_TYPE_KEYS; } else if (matchesPrefix(firstBytes, "-----BEGIN PGP MESSAGE-----")) { // this is NOT application/pgp-encrypted, see RFC 3156! mimeType = Constants.MIME_TYPE_ENCRYPTED_ALTERNATE; } else { mimeType = charsetVerifier.getGuessedMimeType(); } metadata = new OpenPgpMetadata(originalFilename, mimeType, literalData.getModificationTime().getTime(), alreadyWritten, charsetVerifier.getCharset()); log.add(LogType.MSG_DC_CLEAR_META_MIME, indent + 1, mimeType); Log.d(Constants.TAG, metadata.toString()); indent -= 1; if (esResult != null) { if (esResult.encryptedData.isIntegrityProtected()) { if (esResult.encryptedData.verify()) { log.add(LogType.MSG_DC_INTEGRITY_CHECK_OK, indent); } else { log.add(LogType.MSG_DC_ERROR_INTEGRITY_CHECK, indent); return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log); } } else if (!signatureChecker.isInitialized()) { // If no signature is present, we *require* an MDC! // Handle missing integrity protection like failed integrity protection! // The MDC packet can be stripped by an attacker! log.add(LogType.MSG_DC_INSECURE_MDC_MISSING, indent); decryptionResultBuilder.setInsecure(true); } } updateProgress(R.string.progress_done, 100, 100); log.add(LogType.MSG_DC_OK, indent); // Return a positive result, with metadata and verification info DecryptVerifyResult result = new DecryptVerifyResult(DecryptVerifyResult.RESULT_OK, log); result.setCachedCryptoInputParcel(cryptoInput); result.setSignatureResult(signatureChecker.getSignatureResult()); result.setDecryptionResult(decryptionResultBuilder.build()); result.setDecryptionMetadata(metadata); result.mOperationTime = opTime; return result; } private EncryptStreamResult handleEncryptedPacket(PgpDecryptVerifyInputParcel input, CryptoInputParcel cryptoInput, PGPEncryptedDataList enc, OperationLog log, int indent, boolean useBackupCode) throws PGPException { EncryptStreamResult result = new EncryptStreamResult(); boolean asymmetricPacketFound = false; boolean symmetricPacketFound = false; boolean anyPacketFound = false; boolean decryptedSessionKeyAvailable = false; PGPPublicKeyEncryptedData encryptedDataAsymmetric = null; PGPPBEEncryptedData encryptedDataSymmetric = null; CanonicalizedSecretKey decryptionKey = null; CachingDataDecryptorFactory cachedKeyDecryptorFactory = new CachingDataDecryptorFactory( Constants.BOUNCY_CASTLE_PROVIDER_NAME, cryptoInput.getCryptoData()); ; Passphrase passphrase = null; Iterator<?> it = enc.getEncryptedDataObjects(); // go through all objects and find one we can decrypt while (it.hasNext()) { Object obj = it.next(); if (obj instanceof PGPPublicKeyEncryptedData) { anyPacketFound = true; PGPPublicKeyEncryptedData encData = (PGPPublicKeyEncryptedData) obj; long subKeyId = encData.getKeyID(); log.add(LogType.MSG_DC_ASYM, indent, KeyFormattingUtils.convertKeyIdToHex(subKeyId)); decryptedSessionKeyAvailable = cachedKeyDecryptorFactory.hasCachedSessionData(encData); if (decryptedSessionKeyAvailable) { asymmetricPacketFound = true; encryptedDataAsymmetric = encData; break; } CachedPublicKeyRing cachedPublicKeyRing; try { // get actual keyring object based on master key id cachedPublicKeyRing = mProviderHelper .getCachedPublicKeyRing(KeyRings.buildUnifiedKeyRingsFindBySubkeyUri(subKeyId)); long masterKeyId = cachedPublicKeyRing.getMasterKeyId(); // allow only specific keys for decryption? if (input.getAllowedKeyIds() != null) { Log.d(Constants.TAG, "encData.getKeyID(): " + subKeyId); Log.d(Constants.TAG, "mAllowedKeyIds: " + input.getAllowedKeyIds()); Log.d(Constants.TAG, "masterKeyId: " + masterKeyId); if (!input.getAllowedKeyIds().contains(masterKeyId)) { // this key is in our db, but NOT allowed! // continue with the next packet in the while loop result.skippedDisallowedKey = true; log.add(LogType.MSG_DC_ASKIP_NOT_ALLOWED, indent + 1); continue; } } SecretKeyType secretKeyType = cachedPublicKeyRing.getSecretKeyType(subKeyId); if (!secretKeyType.isUsable()) { decryptionKey = null; log.add(LogType.MSG_DC_ASKIP_UNAVAILABLE, indent + 1); continue; } // get actual subkey which has been used for this encryption packet CanonicalizedSecretKeyRing canonicalizedSecretKeyRing = mProviderHelper .getCanonicalizedSecretKeyRing(masterKeyId); CanonicalizedSecretKey candidateDecryptionKey = canonicalizedSecretKeyRing .getSecretKey(subKeyId); if (!candidateDecryptionKey.canEncrypt()) { log.add(LogType.MSG_DC_ASKIP_BAD_FLAGS, indent + 1); continue; } if (secretKeyType == SecretKeyType.DIVERT_TO_CARD) { passphrase = null; } else if (secretKeyType == SecretKeyType.PASSPHRASE_EMPTY) { passphrase = new Passphrase(""); } else if (cryptoInput.hasPassphrase()) { passphrase = cryptoInput.getPassphrase(); } else { // if no passphrase was explicitly set try to get it from the cache service try { // returns "" if key has no passphrase passphrase = getCachedPassphrase(subKeyId); log.add(LogType.MSG_DC_PASS_CACHED, indent + 1); } catch (PassphraseCacheInterface.NoSecretKeyException e) { log.add(LogType.MSG_DC_ERROR_NO_KEY, indent + 1); return result.with(new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log)); } // if passphrase was not cached, return here indicating that a passphrase is missing! if (passphrase == null) { log.add(LogType.MSG_DC_PENDING_PASSPHRASE, indent + 1); return result.with(new DecryptVerifyResult(log, RequiredInputParcel.createRequiredDecryptPassphrase(masterKeyId, subKeyId), cryptoInput)); } } // check for insecure encryption key if (!PgpSecurityConstants.isSecureKey(candidateDecryptionKey)) { log.add(LogType.MSG_DC_INSECURE_KEY, indent + 1); result.insecureEncryptionKey = true; } // we're good, write down the data for later asymmetricPacketFound = true; encryptedDataAsymmetric = encData; decryptionKey = candidateDecryptionKey; } catch (PgpKeyNotFoundException | ProviderHelper.NotFoundException e) { // continue with the next packet in the while loop log.add(LogType.MSG_DC_ASKIP_NO_KEY, indent + 1); continue; } // break out of while, only decrypt the first packet where we have a key break; } else if (obj instanceof PGPPBEEncryptedData) { anyPacketFound = true; log.add(LogType.MSG_DC_SYM, indent); if (!input.isAllowSymmetricDecryption()) { log.add(LogType.MSG_DC_SYM_SKIP, indent + 1); continue; } /* * 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 (!cryptoInput.hasPassphrase()) { try { passphrase = getCachedPassphrase(key.symmetric); log.add(LogType.MSG_DC_PASS_CACHED, indent + 1); } catch (PassphraseCacheInterface.NoSecretKeyException e) { // nvm } if (passphrase == null) { log.add(LogType.MSG_DC_PENDING_PASSPHRASE, indent + 1); RequiredInputParcel requiredInputParcel = useBackupCode ? RequiredInputParcel.createRequiredBackupCode() : RequiredInputParcel.createRequiredSymmetricPassphrase(); return result.with(new DecryptVerifyResult(log, requiredInputParcel, cryptoInput)); } } else { passphrase = cryptoInput.getPassphrase(); } // break out of while, only decrypt the first packet break; } } // More data, just acknowledge and ignore. while (it.hasNext()) { Object obj = it.next(); if (obj instanceof PGPPublicKeyEncryptedData) { PGPPublicKeyEncryptedData encData = (PGPPublicKeyEncryptedData) obj; long subKeyId = encData.getKeyID(); log.add(LogType.MSG_DC_TRAIL_ASYM, indent, KeyFormattingUtils.convertKeyIdToHex(subKeyId)); } else if (obj instanceof PGPPBEEncryptedData) { log.add(LogType.MSG_DC_TRAIL_SYM, indent); } else { log.add(LogType.MSG_DC_TRAIL_UNKNOWN, indent); } } // we made sure above one of these two would be true if (symmetricPacketFound) { PGPDigestCalculatorProvider digestCalcProvider = new JcaPGPDigestCalculatorProviderBuilder() .setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME).build(); PBEDataDecryptorFactory decryptorFactory = new JcePBEDataDecryptorFactoryBuilder(digestCalcProvider) .setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME).build(passphrase.getCharArray()); try { result.cleartextStream = encryptedDataSymmetric.getDataStream(decryptorFactory); } catch (PGPDataValidationException e) { log.add(LogType.MSG_DC_ERROR_SYM_PASSPHRASE, indent + 1); RequiredInputParcel requiredInputParcel = useBackupCode ? RequiredInputParcel.createRequiredBackupCode() : RequiredInputParcel.createRequiredSymmetricPassphrase(); return result.with(new DecryptVerifyResult(log, requiredInputParcel, cryptoInput)); } result.encryptedData = encryptedDataSymmetric; result.symmetricEncryptionAlgo = encryptedDataSymmetric.getSymmetricAlgorithm(decryptorFactory); } else if (asymmetricPacketFound) { CachingDataDecryptorFactory decryptorFactory; if (decryptedSessionKeyAvailable) { decryptorFactory = cachedKeyDecryptorFactory; } else { try { log.add(LogType.MSG_DC_UNLOCKING, indent + 1); if (!decryptionKey.unlock(passphrase)) { log.add(LogType.MSG_DC_ERROR_BAD_PASSPHRASE, indent + 1); return result.with(new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log)); } } catch (PgpGeneralException e) { log.add(LogType.MSG_DC_ERROR_EXTRACT_KEY, indent + 1); return result.with(new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log)); } decryptorFactory = decryptionKey.getCachingDecryptorFactory(cryptoInput); // special case: if the decryptor does not have a session key cached for this encrypted // data, and can't actually decrypt on its own, return a pending intent if (!decryptorFactory.canDecrypt() && !decryptorFactory.hasCachedSessionData(encryptedDataAsymmetric)) { log.add(LogType.MSG_DC_PENDING_NFC, indent + 1); return result.with(new DecryptVerifyResult(log, RequiredInputParcel.createSecurityTokenDecryptOperation( decryptionKey.getRing().getMasterKeyId(), decryptionKey.getKeyId(), encryptedDataAsymmetric.getSessionKey()[0]), cryptoInput)); } } try { result.cleartextStream = encryptedDataAsymmetric.getDataStream(decryptorFactory); } catch (PGPKeyValidationException | ArrayIndexOutOfBoundsException e) { log.add(LogType.MSG_DC_ERROR_CORRUPT_DATA, indent + 1); return result.with(new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log)); } result.symmetricEncryptionAlgo = encryptedDataAsymmetric.getSymmetricAlgorithm(decryptorFactory); result.encryptedData = encryptedDataAsymmetric; Map<ByteBuffer, byte[]> cachedSessionKeys = decryptorFactory.getCachedSessionKeys(); cryptoInput.addCryptoData(cachedSessionKeys); if (cachedSessionKeys.size() >= 1) { Entry<ByteBuffer, byte[]> entry = cachedSessionKeys.entrySet().iterator().next(); result.sessionKey = entry.getKey().array(); result.decryptedSessionKey = entry.getValue(); } } else { // there wasn't even any useful data if (!anyPacketFound) { log.add(LogType.MSG_DC_ERROR_NO_DATA, indent + 1); return result.with(new DecryptVerifyResult(DecryptVerifyResult.RESULT_NO_DATA, log)); } // there was data but key wasn't allowed if (result.skippedDisallowedKey) { log.add(LogType.MSG_DC_ERROR_NO_KEY, indent + 1); return result.with(new DecryptVerifyResult(DecryptVerifyResult.RESULT_KEY_DISALLOWED, log)); } // no packet has been found where we have the corresponding secret key in our db log.add(LogType.MSG_DC_ERROR_NO_KEY, indent + 1); return result.with(new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log)); } 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/bouncycastle/openpgp/examples/ClearSignedFileProcessor.java */ @NonNull private DecryptVerifyResult verifyCleartextSignature(PgpDecryptVerifyInputParcel input, ArmoredInputStream aIn, OutputStream outputStream, int indent) throws IOException, PGPException { OperationLog log = new OperationLog(); byte[] clearText; { // read cleartext ByteArrayOutputStream out = new ByteArrayOutputStream(); updateProgress(R.string.progress_reading_data, 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(); clearText = out.toByteArray(); } if (outputStream != null) { outputStream.write(clearText); outputStream.close(); } updateProgress(R.string.progress_processing_signature, 60, 100); JcaSkipMarkerPGPObjectFactory pgpFact = new JcaSkipMarkerPGPObjectFactory(aIn); PgpSignatureChecker signatureChecker = new PgpSignatureChecker(mProviderHelper, input.getSenderAddress()); Object o = pgpFact.nextObject(); if (!signatureChecker.initializeSignature(o, log, indent + 1)) { log.add(LogType.MSG_DC_ERROR_INVALID_DATA, 0); return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log); } if (signatureChecker.isInitialized()) { try { updateProgress(R.string.progress_verifying_signature, 90, 100); signatureChecker.updateSignatureWithCleartext(clearText); signatureChecker.verifySignature(log, indent); } catch (SignatureException e) { Log.d(Constants.TAG, "SignatureException", e); return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log); } } updateProgress(R.string.progress_done, 100, 100); log.add(LogType.MSG_DC_OK, indent); OpenPgpMetadata metadata = new OpenPgpMetadata("", "text/plain", -1, clearText.length, "utf-8"); DecryptVerifyResult result = new DecryptVerifyResult(DecryptVerifyResult.RESULT_OK, log); result.setSignatureResult(signatureChecker.getSignatureResult()); result.setDecryptionResult(new OpenPgpDecryptionResult(OpenPgpDecryptionResult.RESULT_NOT_ENCRYPTED)); result.setDecryptionMetadata(metadata); return result; } @NonNull private DecryptVerifyResult verifyDetachedSignature(PgpDecryptVerifyInputParcel input, InputData inputData, OutputStream out, int indent) throws IOException, PGPException { OperationLog log = new OperationLog(); updateProgress(R.string.progress_processing_signature, 0, 100); InputStream detachedSigIn = new ByteArrayInputStream(input.getDetachedSignature()); detachedSigIn = PGPUtil.getDecoderStream(detachedSigIn); JcaSkipMarkerPGPObjectFactory pgpFact = new JcaSkipMarkerPGPObjectFactory(detachedSigIn); Object o = pgpFact.nextObject(); if (o instanceof PGPCompressedData) { PGPCompressedData c1 = (PGPCompressedData) o; pgpFact = new JcaSkipMarkerPGPObjectFactory(c1.getDataStream()); o = pgpFact.nextObject(); } PgpSignatureChecker signatureChecker = new PgpSignatureChecker(mProviderHelper, input.getSenderAddress()); if (!signatureChecker.initializeSignature(o, log, indent + 1)) { log.add(LogType.MSG_DC_ERROR_INVALID_DATA, 0); return new DecryptVerifyResult(DecryptVerifyResult.RESULT_ERROR, log); } if (signatureChecker.isInitialized()) { updateProgress(R.string.progress_reading_data, 60, 100); ProgressScaler progressScaler = new ProgressScaler(mProgressable, 60, 90, 100); long alreadyWritten = 0; long wholeSize = inputData.getSize() - inputData.getStreamPosition(); int length; byte[] buffer = new byte[1 << 16]; InputStream in = inputData.getInputStream(); while ((length = in.read(buffer)) > 0) { if (out != null) { out.write(buffer, 0, length); } // update signature buffer if signature is also present signatureChecker.updateSignatureData(buffer, 0, length); alreadyWritten += length; if (wholeSize > 0) { long progress = 100 * alreadyWritten / wholeSize; // stop at 100% for wrong file sizes... if (progress > 100) { progress = 100; } progressScaler.setProgress((int) progress, 100); } } updateProgress(R.string.progress_verifying_signature, 90, 100); log.add(LogType.MSG_DC_CLEAR_SIGNATURE_CHECK, indent); signatureChecker.verifySignature(log, indent); } updateProgress(R.string.progress_done, 100, 100); log.add(LogType.MSG_DC_OK, indent); // TODO return metadata object? DecryptVerifyResult result = new DecryptVerifyResult(DecryptVerifyResult.RESULT_OK, log); result.setSignatureResult(signatureChecker.getSignatureResult()); result.setDecryptionResult(new OpenPgpDecryptionResult(OpenPgpDecryptionResult.RESULT_NOT_ENCRYPTED)); return result; } 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 = readPastEOL(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 = readPastEOL(bOut, ch, fIn); break; } } while ((ch = fIn.read()) >= 0); if (ch < 0) { lookAhead = -1; } return lookAhead; } private static int readPastEOL(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 byte[] getLineSeparator() { String nl = System.getProperty("line.separator"); return nl.getBytes(); } /// Convenience method - Trivially checks if a byte array matches the bytes of a plain text string // Assumes data.length >= needle.length() static boolean matchesPrefix(byte[] data, String needle) { byte[] needleBytes = needle.getBytes(); for (int i = 0; i < needle.length(); i++) { if (data[i] != needleBytes[i]) { return false; } } return true; } }