allow setting custom headers in autocrypt setup message

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/operations/BackupOperation.java

@@ -26,8 +26,10 @@ import java.io.OutputStream;
 import java.text.SimpleDateFormat;
 import java.util.Collections;
 import java.util.Date;
+import java.util.List;
 import java.util.Locale;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.regex.Pattern;
 
 import android.content.Context;
 import android.database.Cursor;
@@ -84,6 +86,9 @@ public class BackupOperation extends BaseOperation<BackupKeyringParcel> {
     private static final int INDEX_MASTER_KEY_ID = 0;
     private static final int INDEX_HAS_ANY_SECRET = 1;
 
+    // this is a very simple matcher, we only need basic sanitization
+    private static final Pattern HEADER_PATTERN = Pattern.compile("[a-zA-Z0-9_-]+: [^\\n]+");
+
     public BackupOperation(Context context, KeyRepository keyRepository, Progressable
             progressable) {
         super(context, keyRepository, progressable);
@@ -130,7 +135,7 @@ public class BackupOperation extends BaseOperation<BackupKeyringParcel> {
 
             CountingOutputStream outStream = new CountingOutputStream(new BufferedOutputStream(plainOut));
             boolean backupSuccess = exportKeysToStream(log, backupInput.getMasterKeyIds(),
-                    backupInput.getExportSecret(), backupInput.getExportPublic(), outStream);
+                    backupInput.getExportSecret(), backupInput.getExportPublic(), outStream, backupInput.getExtraHeaders());
 
             if (!backupSuccess) {
                 // if there was an error, it will be in the log so we just have to return
@@ -215,7 +220,7 @@ public class BackupOperation extends BaseOperation<BackupKeyringParcel> {
     }
 
     boolean exportKeysToStream(OperationLog log, long[] masterKeyIds, boolean exportSecret, boolean exportPublic,
-            OutputStream outStream) {
+            OutputStream outStream, List<String> extraSecretKeyHeaders) {
         // noinspection unused TODO use these in a log entry
         int okSecret = 0, okPublic = 0;
 
@@ -253,9 +258,10 @@ public class BackupOperation extends BaseOperation<BackupKeyringParcel> {
                     boolean hasSecret = cursor.getInt(INDEX_HAS_ANY_SECRET) > 0;
                     if (exportSecret && hasSecret) {
                         log.add(LogType.MSG_BACKUP_SECRET, 2, KeyFormattingUtils.beautifyKeyId(masterKeyId));
-                        if (writeSecretKeyToStream(masterKeyId, log, outStream)) {
+                        if (writeSecretKeyToStream(masterKeyId, log, outStream, extraSecretKeyHeaders)) {
                             okSecret += 1;
                         }
+                        extraSecretKeyHeaders = null;
                     }
                 }
 
@@ -300,12 +306,17 @@ public class BackupOperation extends BaseOperation<BackupKeyringParcel> {
         return true;
     }
 
-    private boolean writeSecretKeyToStream(long masterKeyId, OperationLog log, OutputStream outStream)
+    private boolean writeSecretKeyToStream(long masterKeyId, OperationLog log, OutputStream outStream,
+            List<String> extraSecretKeyHeaders)
             throws IOException {
         ArmoredOutputStream arOutStream = null;
 
         try {
             arOutStream = new ArmoredOutputStream(outStream);
+            if (extraSecretKeyHeaders != null) {
+                addExtraHeadersToStream(arOutStream, extraSecretKeyHeaders);
+            }
+
             byte[] data = mKeyRepository.loadSecretKeyRingData(masterKeyId);
             UncachedKeyRing uncachedKeyRing = UncachedKeyRing.decodeFromData(data);
             CanonicalizedSecretKeyRing ring = (CanonicalizedSecretKeyRing) uncachedKeyRing.canonicalize(log, 2, true);
@@ -320,6 +331,16 @@ public class BackupOperation extends BaseOperation<BackupKeyringParcel> {
         return true;
     }
 
+    private void addExtraHeadersToStream(ArmoredOutputStream arOutStream, List<String> headers) {
+        for (String header : headers) {
+            if (!HEADER_PATTERN.matcher(header).matches()) {
+                throw new IllegalArgumentException("bad header format");
+            }
+            int sep = header.indexOf(':');
+            arOutStream.setHeader(header.substring(0, sep), header.substring(sep + 2));
+        }
+    }
+
     private Cursor queryForKeys(long[] masterKeyIds) {
         String selection = null, selectionArgs[] = null;
 

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/remote/OpenPgpService.java

@@ -829,10 +829,12 @@ public class OpenPgpService extends Service {
                 }
             }
 
+            List<String> headerLines = data.getStringArrayListExtra(OpenPgpApi.EXTRA_CUSTOM_HEADERS);
+
             Passphrase autocryptTransferCode = Numeric9x4PassphraseUtil.generateNumeric9x4Passphrase();
             CryptoInputParcel inputParcel = CryptoInputParcel.createCryptoInputParcel(autocryptTransferCode);
 
-            BackupKeyringParcel input = BackupKeyringParcel.createExportAutocryptSetupMessage(masterKeyIds);
+            BackupKeyringParcel input = BackupKeyringParcel.createExportAutocryptSetupMessage(masterKeyIds, headerLines);
             BackupOperation op = new BackupOperation(this, mKeyRepository, null);
             ExportResult pgpResult = op.execute(input, inputParcel, outputStream);
 

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/service/BackupKeyringParcel.java

@@ -18,6 +18,8 @@
 package org.sufficientlysecure.keychain.service;
 
 
+import java.util.List;
+
 import android.net.Uri;
 import android.os.Parcelable;
 import android.support.annotation.Nullable;
@@ -36,15 +38,24 @@ public abstract class BackupKeyringParcel implements Parcelable {
     public abstract boolean getEnableAsciiArmorOutput();
     @Nullable
     public abstract Uri getOutputUri();
+    @Nullable
+    public abstract List<String> getExtraHeaders();
 
     public static BackupKeyringParcel create(long[] masterKeyIds, boolean exportSecret,
             boolean isEncrypted, boolean enableAsciiArmorOutput, Uri outputUri) {
         return new AutoValue_BackupKeyringParcel(
-                masterKeyIds, exportSecret, true, isEncrypted, enableAsciiArmorOutput, outputUri);
+                masterKeyIds, exportSecret, true, isEncrypted, enableAsciiArmorOutput, outputUri, null);
     }
 
-    public static BackupKeyringParcel createExportAutocryptSetupMessage(long[] masterKeyIds) {
+    public static BackupKeyringParcel create(long[] masterKeyIds, boolean exportSecret,
+            boolean isEncrypted, boolean enableAsciiArmorOutput, Uri outputUri, List<String> extraHeaders) {
         return new AutoValue_BackupKeyringParcel(
-                masterKeyIds, true, false, true, true, null);
+                masterKeyIds, exportSecret, true, isEncrypted, enableAsciiArmorOutput, outputUri, extraHeaders);
+    }
+
+    public static BackupKeyringParcel createExportAutocryptSetupMessage(long[] masterKeyIds,
+            List<String> extraHeaders) {
+        return new AutoValue_BackupKeyringParcel(
+                masterKeyIds, true, false, true, true, null, extraHeaders);
     }
 }

OpenKeychain/src/test/java/org/sufficientlysecure/keychain/operations/BackupOperationTest.java

@@ -24,6 +24,7 @@ import java.io.PipedInputStream;
 import java.io.PipedOutputStream;
 import java.io.PrintStream;
 import java.security.Security;
+import java.util.Arrays;
 import java.util.Iterator;
 
 import android.app.Application;
@@ -157,7 +158,7 @@ public class BackupOperationTest {
         assertTrue("second keyring has local certification", checkForLocal(mStaticRing2));
 
         ByteArrayOutputStream out = new ByteArrayOutputStream();
-        boolean result = op.exportKeysToStream(new OperationLog(), null, false, true, out);
+        boolean result = op.exportKeysToStream(new OperationLog(), null, false, true, out, null);
 
         assertTrue("export must be a success", result);
 
@@ -194,7 +195,7 @@ public class BackupOperationTest {
         }
 
         out = new ByteArrayOutputStream();
-        result = op.exportKeysToStream(new OperationLog(), null, true, true, out);
+        result = op.exportKeysToStream(new OperationLog(), null, true, true, out, null);
 
         assertTrue("export must be a success", result);
 
@@ -238,6 +239,22 @@ public class BackupOperationTest {
 
     }
 
+    @Test
+    public void testExportWithExtraHeaders() throws Exception {
+        BackupOperation op = new BackupOperation(RuntimeEnvironment.application,
+                KeyWritableRepository.create(RuntimeEnvironment.application), null);
+
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+        boolean result = op.exportKeysToStream(
+                new OperationLog(), new long[] { mStaticRing1.getMasterKeyId() }, true, false,
+                        out, Arrays.asList("header: value"));
+
+        assertTrue(result);
+
+        String resultData = new String(out.toByteArray());
+        assertTrue(resultData.startsWith("-----BEGIN PGP PRIVATE KEY BLOCK-----\nheader: value\n\n"));
+    }
+
     @Test
     public void testExportUnencrypted() throws Exception {
         ContentResolver mockResolver = mock(ContentResolver.class);