diff options
Diffstat (limited to 'OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpHelper.java')
-rw-r--r-- | OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpHelper.java | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpHelper.java b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpHelper.java new file mode 100644 index 000000000..7ac904d89 --- /dev/null +++ b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpHelper.java @@ -0,0 +1,219 @@ +/* + * Copyright (C) 2012-2013 Dominik Schürmann <dominik@dominikschuermann.de> + * Copyright (C) 2010 Thialfihar <thi@thialfihar.org> + * + * 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.pgp; + +import java.io.File; +import java.io.FileNotFoundException; +import java.io.IOException; +import java.io.InputStream; +import java.io.RandomAccessFile; +import java.security.SecureRandom; +import java.util.Iterator; +import java.util.regex.Pattern; + +import org.spongycastle.openpgp.PGPEncryptedDataList; +import org.spongycastle.openpgp.PGPObjectFactory; +import org.spongycastle.openpgp.PGPPublicKeyEncryptedData; +import org.spongycastle.openpgp.PGPPublicKeyRing; +import org.spongycastle.openpgp.PGPSecretKey; +import org.spongycastle.openpgp.PGPSecretKeyRing; +import org.spongycastle.openpgp.PGPUtil; +import org.sufficientlysecure.keychain.Constants; +import org.sufficientlysecure.keychain.Id; +import org.sufficientlysecure.keychain.R; +import org.sufficientlysecure.keychain.pgp.exception.NoAsymmetricEncryptionException; +import org.sufficientlysecure.keychain.pgp.exception.PgpGeneralException; +import org.sufficientlysecure.keychain.provider.ProviderHelper; +import org.sufficientlysecure.keychain.util.Log; +import org.sufficientlysecure.keychain.util.ProgressDialogUpdater; + +import android.content.Context; +import android.content.pm.PackageInfo; +import android.content.pm.PackageManager.NameNotFoundException; + +public class PgpHelper { + + public static Pattern PGP_MESSAGE = Pattern.compile( + ".*?(-----BEGIN PGP MESSAGE-----.*?-----END PGP MESSAGE-----).*", Pattern.DOTALL); + + public static Pattern PGP_SIGNED_MESSAGE = Pattern + .compile( + ".*?(-----BEGIN PGP SIGNED MESSAGE-----.*?-----BEGIN PGP SIGNATURE-----.*?-----END PGP SIGNATURE-----).*", + Pattern.DOTALL); + + public static Pattern PGP_PUBLIC_KEY = Pattern.compile( + ".*?(-----BEGIN PGP PUBLIC KEY BLOCK-----.*?-----END PGP PUBLIC KEY BLOCK-----).*", + Pattern.DOTALL); + + public static String getVersion(Context context) { + String version = null; + try { + PackageInfo pi = context.getPackageManager().getPackageInfo(Constants.PACKAGE_NAME, 0); + version = pi.versionName; + return version; + } catch (NameNotFoundException e) { + Log.e(Constants.TAG, "Version could not be retrieved!", e); + return "0.0.0"; + } + } + + public static String getFullVersion(Context context) { + return "OpenPGP Keychain v" + getVersion(context); + } + + public static long getDecryptionKeyId(Context context, InputStream inputStream) + throws PgpGeneralException, NoAsymmetricEncryptionException, IOException { + InputStream in = PGPUtil.getDecoderStream(inputStream); + PGPObjectFactory pgpF = new PGPObjectFactory(in); + PGPEncryptedDataList enc; + Object o = pgpF.nextObject(); + + // the first object might be a PGP marker packet. + if (o instanceof PGPEncryptedDataList) { + enc = (PGPEncryptedDataList) o; + } else { + enc = (PGPEncryptedDataList) pgpF.nextObject(); + } + + if (enc == null) { + throw new PgpGeneralException(context.getString(R.string.error_invalid_data)); + } + + // TODO: currently we always only look at the first known key + // find the secret key + PGPSecretKey secretKey = null; + Iterator<?> it = enc.getEncryptedDataObjects(); + boolean gotAsymmetricEncryption = false; + while (it.hasNext()) { + Object obj = it.next(); + if (obj instanceof PGPPublicKeyEncryptedData) { + gotAsymmetricEncryption = true; + PGPPublicKeyEncryptedData pbe = (PGPPublicKeyEncryptedData) obj; + secretKey = ProviderHelper.getPGPSecretKeyByKeyId(context, pbe.getKeyID()); + if (secretKey != null) { + break; + } + } + } + + if (!gotAsymmetricEncryption) { + throw new NoAsymmetricEncryptionException(); + } + + if (secretKey == null) { + return Id.key.none; + } + + return secretKey.getKeyID(); + } + + public static int getStreamContent(Context context, InputStream inStream) throws IOException { + InputStream in = PGPUtil.getDecoderStream(inStream); + PGPObjectFactory pgpF = new PGPObjectFactory(in); + Object object = pgpF.nextObject(); + while (object != null) { + if (object instanceof PGPPublicKeyRing || object instanceof PGPSecretKeyRing) { + return Id.content.keys; + } else if (object instanceof PGPEncryptedDataList) { + return Id.content.encrypted_data; + } + object = pgpF.nextObject(); + } + + return Id.content.unknown; + } + + /** + * Generate a random filename + * + * @param length + * @return + */ + public static String generateRandomFilename(int length) { + SecureRandom random = new SecureRandom(); + + byte bytes[] = new byte[length]; + random.nextBytes(bytes); + String result = ""; + for (int i = 0; i < length; ++i) { + int v = (bytes[i] + 256) % 64; + if (v < 10) { + result += (char) ('0' + v); + } else if (v < 36) { + result += (char) ('A' + v - 10); + } else if (v < 62) { + result += (char) ('a' + v - 36); + } else if (v == 62) { + result += '_'; + } else if (v == 63) { + result += '.'; + } + } + return result; + } + + /** + * Go once through stream to get length of stream. The length is later used to display progress + * when encrypting/decrypting + * + * @param in + * @return + * @throws IOException + */ + public static long getLengthOfStream(InputStream in) throws IOException { + long size = 0; + long n = 0; + byte dummy[] = new byte[0x10000]; + while ((n = in.read(dummy)) > 0) { + size += n; + } + return size; + } + + /** + * Deletes file securely by overwriting it with random data before deleting it. + * + * TODO: Does this really help on flash storage? + * + * @param context + * @param progress + * @param file + * @throws FileNotFoundException + * @throws IOException + */ + public static void deleteFileSecurely(Context context, ProgressDialogUpdater progress, File file) + throws FileNotFoundException, IOException { + long length = file.length(); + SecureRandom random = new SecureRandom(); + RandomAccessFile raf = new RandomAccessFile(file, "rws"); + raf.seek(0); + raf.getFilePointer(); + byte[] data = new byte[1 << 16]; + int pos = 0; + String msg = context.getString(R.string.progress_deleting_securely, file.getName()); + while (pos < length) { + if (progress != null) + progress.setProgress(msg, (int) (100 * pos / length), 100); + random.nextBytes(data); + raf.write(data); + pos += data.length; + } + raf.close(); + file.delete(); + } +} |