private void downloadMediaFileIfChanged(File mediaDir, MediaFile m, FormStatus fs) throws Exception { File mediaFile = new File(mediaDir, m.filename); if (m.hash.startsWith(MD5_COLON_PREFIX)) { // see if the file exists and has the same hash String hashToMatch = m.hash.substring(MD5_COLON_PREFIX.length()); if (mediaFile.exists()) { String hash = FileSystemUtils.getMd5Hash(mediaFile); if (hash.equalsIgnoreCase(hashToMatch)) return; mediaFile.delete(); } } if (isCancelled()) { fs.setStatusString("aborting fetch of media file...", true); EventBus.publish(new FormStatusEvent(fs)); throw new TransmissionException("Transfer cancelled by user."); } AggregateUtils.commonDownloadFile(serverInfo, mediaFile, m.downloadUrl); }
private static boolean decryptSubmissionFiles( String base64EncryptedSymmetricKey, FormInstanceMetadata fim, List<String> mediaNames, String encryptedSubmissionFile, String base64EncryptedElementSignature, PrivateKey rsaPrivateKey, File instanceDir, File unencryptedDir) throws FileSystemException, CryptoException, ParsingException { EncryptionInformation ei = new EncryptionInformation(base64EncryptedSymmetricKey, fim.instanceId, rsaPrivateKey); byte[] elementDigest; try { // construct the base64-encoded RSA-encrypted symmetric key Cipher pkCipher; pkCipher = Cipher.getInstance(ASYMMETRIC_ALGORITHM); // extract digest pkCipher.init(Cipher.DECRYPT_MODE, rsaPrivateKey); byte[] encryptedElementSignature = Base64.decodeBase64(base64EncryptedElementSignature); elementDigest = pkCipher.doFinal(encryptedElementSignature); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); throw new CryptoException( "Error decrypting base64EncryptedElementSignature Cause: " + e.toString()); } catch (NoSuchPaddingException e) { e.printStackTrace(); throw new CryptoException( "Error decrypting base64EncryptedElementSignature Cause: " + e.toString()); } catch (InvalidKeyException e) { e.printStackTrace(); throw new CryptoException( "Error decrypting base64EncryptedElementSignature Cause: " + e.toString()); } catch (IllegalBlockSizeException e) { e.printStackTrace(); throw new CryptoException( "Error decrypting base64EncryptedElementSignature Cause: " + e.toString()); } catch (BadPaddingException e) { e.printStackTrace(); throw new CryptoException( "Error decrypting base64EncryptedElementSignature Cause: " + e.toString()); } // NOTE: will decrypt only the files in the media list, plus the encryptedSubmissionFile File[] allFiles = instanceDir.listFiles(); List<File> filesToProcess = new ArrayList<File>(); for (File f : allFiles) { if (mediaNames.contains(f.getName())) { filesToProcess.add(f); } else if (encryptedSubmissionFile.equals(f.getName())) { filesToProcess.add(f); } } // should have all media files plus one submission.xml.enc file if (filesToProcess.size() != mediaNames.size() + 1) { // figure out what we're missing... int lostFileCount = 0; List<String> missing = new ArrayList<String>(); for (String name : mediaNames) { if (name == null) { // this was lost due to an pre-ODK Aggregate 1.4.5 mark-as-complete action ++lostFileCount; continue; } File f = new File(instanceDir, name); if (!filesToProcess.contains(f)) { missing.add(name); } } StringBuilder b = new StringBuilder(); for (String name : missing) { b.append(" ").append(name); } if (!filesToProcess.contains(new File(instanceDir, encryptedSubmissionFile))) { b.append(" ").append(encryptedSubmissionFile); throw new FileSystemException( "Error decrypting: " + instanceDir.getName() + " Missing files:" + b.toString()); } else { // ignore the fact that we don't have the lost files if (filesToProcess.size() + lostFileCount != mediaNames.size() + 1) { throw new FileSystemException( "Error decrypting: " + instanceDir.getName() + " Missing files:" + b.toString()); } } } // decrypt the media files IN ORDER. for (String mediaName : mediaNames) { String displayedName = (mediaName == null) ? "<missing .enc file>" : mediaName; File f = (mediaName == null) ? null : new File(instanceDir, mediaName); try { decryptFile(ei, f, unencryptedDir); } catch (InvalidKeyException e) { e.printStackTrace(); throw new CryptoException("Error decrypting:" + displayedName + " Cause: " + e.toString()); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); throw new CryptoException("Error decrypting:" + displayedName + " Cause: " + e.toString()); } catch (InvalidAlgorithmParameterException e) { e.printStackTrace(); throw new CryptoException("Error decrypting:" + displayedName + " Cause: " + e.toString()); } catch (NoSuchPaddingException e) { e.printStackTrace(); throw new CryptoException("Error decrypting:" + displayedName + " Cause: " + e.toString()); } catch (IOException e) { e.printStackTrace(); throw new FileSystemException( "Error decrypting:" + displayedName + " Cause: " + e.toString()); } } // decrypt the submission file File f = new File(instanceDir, encryptedSubmissionFile); try { decryptFile(ei, f, unencryptedDir); } catch (InvalidKeyException e) { e.printStackTrace(); throw new CryptoException("Error decrypting:" + f.getName() + " Cause: " + e.toString()); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); throw new CryptoException("Error decrypting:" + f.getName() + " Cause: " + e.toString()); } catch (InvalidAlgorithmParameterException e) { e.printStackTrace(); throw new CryptoException("Error decrypting:" + f.getName() + " Cause: " + e.toString()); } catch (NoSuchPaddingException e) { e.printStackTrace(); throw new CryptoException("Error decrypting:" + f.getName() + " Cause: " + e.toString()); } catch (IOException e) { e.printStackTrace(); throw new FileSystemException("Error decrypting:" + f.getName() + " Cause: " + e.toString()); } // get the FIM for the decrypted submission file File submissionFile = new File( unencryptedDir, encryptedSubmissionFile.substring(0, encryptedSubmissionFile.lastIndexOf(".enc"))); FormInstanceMetadata submissionFim; try { Document subDoc = XmlManipulationUtils.parseXml(submissionFile); submissionFim = XmlManipulationUtils.getFormInstanceMetadata(subDoc.getRootElement()); } catch (ParsingException e) { e.printStackTrace(); throw new FileSystemException( "Error decrypting: " + submissionFile.getName() + " Cause: " + e.toString()); } catch (FileSystemException e) { e.printStackTrace(); throw new FileSystemException( "Error decrypting: " + submissionFile.getName() + " Cause: " + e.getMessage()); } boolean same = submissionFim.xparam.formId.equals(fim.xparam.formId); if (!same) { throw new FileSystemException( "Error decrypting:" + unencryptedDir.getName() + " Cause: form instance metadata differs from that in manifest"); } // Construct the element signature string StringBuilder b = new StringBuilder(); appendElementSignatureSource(b, fim.xparam.formId); if (fim.xparam.modelVersion != null) { appendElementSignatureSource(b, Long.toString(fim.xparam.modelVersion)); } appendElementSignatureSource(b, base64EncryptedSymmetricKey); appendElementSignatureSource(b, fim.instanceId); boolean missingFile = false; for (String encFilename : mediaNames) { if (encFilename == null) { missingFile = true; continue; } File decryptedFile = new File(unencryptedDir, encFilename.substring(0, encFilename.lastIndexOf(".enc"))); if (decryptedFile.getName().endsWith(".missing")) { // this is a missing file -- we will not be able to // confirm the signature of the submission. missingFile = true; continue; } String md5 = FileSystemUtils.getMd5Hash(decryptedFile); appendElementSignatureSource(b, decryptedFile.getName() + "::" + md5); } String md5 = FileSystemUtils.getMd5Hash(submissionFile); appendElementSignatureSource(b, submissionFile.getName() + "::" + md5); // compute the digest of the element signature string byte[] messageDigest; try { MessageDigest md = MessageDigest.getInstance("MD5"); md.update(b.toString().getBytes("UTF-8")); messageDigest = md.digest(); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); throw new CryptoException("Error computing xml signature Cause: " + e.toString()); } catch (UnsupportedEncodingException e) { e.printStackTrace(); throw new CryptoException("Error computing xml signature Cause: " + e.toString()); } same = true; for (int i = 0; i < messageDigest.length; ++i) { if (messageDigest[i] != elementDigest[i]) { same = false; break; } } return same; }