update database to store repo key fingerprint

The stored fingerprint is needed for comparing new, incoming repos that are
in the Add Repo dialog.  This is to prevent malicious use of the automated
adding of repos via QR Codes, NFC, etc.  The only other option that I could
think of for handling this situation is for the Add Repo dialog to open a
socket to the proposed repo to get its pubkey.  That seems much less
desirable than just storing the fingerprints in the database.

src/org/fdroid/fdroid/DB.java

@@ -21,10 +21,12 @@ package org.fdroid.fdroid;
 
 import android.annotation.SuppressLint;
 import java.io.File;
+import java.security.MessageDigest;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Date;
+import java.util.Formatter;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
@@ -434,7 +436,8 @@ public class DB {
     private static final String CREATE_TABLE_REPO = "create table "
             + TABLE_REPO + " (id integer primary key, address text not null, "
             + "name text, description text, inuse integer not null, "
-            + "priority integer not null, pubkey text, lastetag text);";
+            + "priority integer not null, pubkey text, fingerprint text, "
+            + "lastetag text);";
 
     public static class Repo {
         public int id;
@@ -444,10 +447,11 @@ public class DB {
         public boolean inuse;
         public int priority;
         public String pubkey; // null for an unsigned repo
+        public String fingerprint; // always null for an unsigned repo
         public String lastetag; // last etag we updated from, null forces update
     }
 
-    private final int DBVersion = 28;
+    private final int DBVersion = 29;
 
     private static void createAppApk(SQLiteDatabase db) {
         db.execSQL(CREATE_TABLE_APP);
@@ -457,6 +461,26 @@ public class DB {
         db.execSQL("create index apk_id on " + TABLE_APK + " (id);");
     }
 
+    public static String calcFingerprint(String pubkey) {
+        String ret = null;
+        try {
+            // keytool -list -v gives you the SHA-256 fingerprint
+            MessageDigest digest = MessageDigest.getInstance("SHA-256");
+            digest.update(Hasher.unhex(pubkey));
+            byte[] fingerprint = digest.digest();
+            Formatter formatter = new Formatter(new StringBuilder());
+            for (int i = 1; i < fingerprint.length; i++) {
+                formatter.format("%02X", fingerprint[i]);
+            }
+            ret = formatter.toString();
+            formatter.close();
+        } catch (Exception e) {
+            Log.w("FDroid", "Unable to get certificate fingerprint.\n"
+                    + Log.getStackTraceString(e));
+        }
+        return ret;
+    }
+
     public void resetTransient(SQLiteDatabase db) {
         mContext.getSharedPreferences("FDroid", Context.MODE_PRIVATE).edit()
                 .putBoolean("triedEmptyUpdate", false).commit();
@@ -491,8 +515,10 @@ public class DB {
                     mContext.getString(R.string.default_repo_name));
             values.put("description",
                     mContext.getString(R.string.default_repo_description));
-            values.put("pubkey",
+            String pubkey = mContext.getString(R.string.default_repo_pubkey);
-                    mContext.getString(R.string.default_repo_pubkey));
+            String fingerprint = DB.calcFingerprint(pubkey);
+            values.put("pubkey", pubkey);
+            values.put("fingerprint", fingerprint);
             values.put("inuse", 1);
             values.put("priority", 10);
             values.put("lastetag", (String) null);
@@ -505,8 +531,9 @@ public class DB {
                     mContext.getString(R.string.default_repo_name2));
             values.put("description",
                     mContext.getString(R.string.default_repo_description2));
-            values.put("pubkey",
+            // default #2 is /archive which has the same key as /repo
-                    mContext.getString(R.string.default_repo_pubkey));
+            values.put("pubkey", pubkey);
+            values.put("fingerprint", fingerprint);
             values.put("inuse", 0);
             values.put("priority", 20);
             values.put("lastetag", (String) null);
@@ -568,6 +595,28 @@ public class DB {
                     mContext.getString(R.string.default_repo_address2) });
             }
 
+            if (oldVersion < 29) {
+                if (!columnExists(db, TABLE_REPO, "fingerprint"))
+                    db.execSQL("alter table " + TABLE_REPO + " add column fingerprint text");
+                List<Repo> oldrepos = new ArrayList<Repo>();
+                Cursor c = db.query(TABLE_REPO,
+                        new String[] { "address", "pubkey" },
+                        null, null, null, null, null);
+                c.moveToFirst();
+                while (!c.isAfterLast()) {
+                    Repo repo = new Repo();
+                    repo.address = c.getString(0);
+                    repo.pubkey = c.getString(1);
+                    oldrepos.add(repo);
+                    c.moveToNext();
+                }
+                c.close();
+                for (Repo repo : oldrepos) {
+                    ContentValues values = new ContentValues();
+                    values.put("fingerprint", DB.calcFingerprint(repo.pubkey));
+                    db.update(TABLE_REPO, values, "address = ?", new String[] { repo.address });
+                }
+            }
         }
 
     }
@@ -1245,7 +1294,8 @@ public class DB {
         Cursor c = null;
         try {
             c = db.query(TABLE_REPO, new String[] { "address", "name",
-                "description", "inuse", "priority", "pubkey", "lastetag" },
+                "description", "inuse", "priority", "pubkey", "fingerprint",
+                "lastetag" },
                     "id = ?", new String[] { Integer.toString(id) }, null, null, null);
             if (!c.moveToFirst())
                 return null;
@@ -1257,7 +1307,8 @@ public class DB {
             repo.inuse = (c.getInt(3) == 1);
             repo.priority = c.getInt(4);
             repo.pubkey = c.getString(5);
-            repo.lastetag = c.getString(6);
+            repo.fingerprint = c.getString(6);
+            repo.lastetag = c.getString(7);
             return repo;
         } finally {
             if (c != null)
@@ -1271,7 +1322,8 @@ public class DB {
         Cursor c = null;
         try {
             c = db.query(TABLE_REPO, new String[] { "id", "address", "name",
-                    "description", "inuse", "priority", "pubkey", "lastetag" },
+                    "description", "inuse", "priority", "pubkey", "fingerprint",
+                    "lastetag" },
                     null, null, null, null, "priority");
             c.moveToFirst();
             while (!c.isAfterLast()) {
@@ -1283,7 +1335,8 @@ public class DB {
                 repo.inuse = (c.getInt(4) == 1);
                 repo.priority = c.getInt(5);
                 repo.pubkey = c.getString(6);
-                repo.lastetag = c.getString(7);
+                repo.fingerprint = c.getString(7);
+                repo.lastetag = c.getString(8);
                 repos.add(repo);
                 c.moveToNext();
             }
@@ -1316,6 +1369,12 @@ public class DB {
         values.put("inuse", repo.inuse);
         values.put("priority", repo.priority);
         values.put("pubkey", repo.pubkey);
+        if (repo.pubkey != null && repo.fingerprint == null) {
+            // we got a new pubkey, so calc the fingerprint
+            values.put("fingerprint", DB.calcFingerprint(repo.pubkey));
+        } else {
+            values.put("fingerprint", repo.fingerprint);
+        }
         values.put("lastetag", (String) null);
         db.update(TABLE_REPO, values, "address = ?",
                 new String[] { repo.address });
@@ -1329,7 +1388,8 @@ public class DB {
     }
 
     public void addRepo(String address, String name, String description,
-            int priority, String pubkey, boolean inuse) {
+            int priority, String pubkey, String fingerprint, boolean inuse)
+                    throws SecurityException {
         ContentValues values = new ContentValues();
         values.put("address", address);
         values.put("name", name);
@@ -1337,6 +1397,17 @@ public class DB {
         values.put("inuse", inuse ? 1 : 0);
         values.put("priority", priority);
         values.put("pubkey", pubkey);
+        String calcedFingerprint = DB.calcFingerprint(pubkey);
+        if (fingerprint == null) {
+            fingerprint = calcedFingerprint;
+        } else {
+            fingerprint = fingerprint.toUpperCase();
+            if (!fingerprint.equals(calcedFingerprint)) {
+                throw new SecurityException("Given fingerprint does not match calculated one! ("
+                        + fingerprint + " != " + calcedFingerprint);
+            }
+        }
+        values.put("fingerprint", fingerprint);
         values.put("lastetag", (String) null);
         db.insert(TABLE_REPO, null, values);
     }

src/org/fdroid/fdroid/ManageRepo.java

@@ -19,10 +19,8 @@
 
 package org.fdroid.fdroid;
 
-import java.security.MessageDigest;
 import java.util.ArrayList;
 import java.util.Date;
-import java.util.Formatter;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
@@ -157,9 +155,8 @@ public class ManageRepo extends ListActivity {
             } else {
                 server_line.put("inuse", R.drawable.btn_check_off);
             }
-            if (repo.pubkey != null) {
+            if (repo.fingerprint != null) {
-                String fingerprint = getRepoFingerprint(repo);
+                server_line.put("fingerprint", repo.fingerprint);
-                server_line.put("fingerprint", fingerprint);
             }
             result.add(server_line);
         }
@@ -202,10 +199,10 @@ public class ManageRepo extends ListActivity {
         return true;
     }
 
-    protected void addRepo(String repoUri) {
+    protected void addRepo(String repoUri, String fingerprint) {
         try {
             DB db = DB.getDB();
-            db.addRepo(repoUri, null, null, 10, null, true);
+            db.addRepo(repoUri, null, null, 10, null, fingerprint, true);
         } finally {
             DB.releaseDB();
         }
@@ -230,26 +227,6 @@ public class ManageRepo extends ListActivity {
         return null;
     }
 
-    protected String getRepoFingerprint(Repo repo) {
-        String ret = null;
-        try {
-            // keytool -list -v gives you the SHA-256 fingerprint
-            MessageDigest digest = MessageDigest.getInstance("SHA-256");
-            digest.update(Hasher.unhex(repo.pubkey));
-            byte[] fingerprint = digest.digest();
-            Formatter formatter = new Formatter(new StringBuilder());
-            for (int i = 1; i < fingerprint.length; i++) {
-                formatter.format("%02X", fingerprint[i]);
-            }
-            ret = formatter.toString();
-            formatter.close();
-        } catch (Exception e) {
-            Log.w("FDroid", "Unable to get certificate fingerprint.\n"
-                    + Log.getStackTraceString(e));
-        }
-        return ret;
-    }
-
     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {
@@ -275,7 +252,8 @@ public class ManageRepo extends ListActivity {
                 new DialogInterface.OnClickListener() {
                     @Override
                     public void onClick(DialogInterface dialog, int which) {
-                        addRepo(uriEditText.getText().toString());
+                        addRepo(uriEditText.getText().toString(),
+                                fingerprintEditText.getText().toString());
                         changed = true;
                         redraw();
                     }