From a02f985efaa29371a823266ba2ffbf71218243ae Mon Sep 17 00:00:00 2001
From: Hans-Christoph Steiner <hans@eds.org>
Date: Tue, 28 Jan 2014 19:02:23 -0500
Subject: [PATCH] for signed repo with public key, guarantee fingerprint is
 also set

The stored fingerprint is checked when a repo URI is received by FDroid to
prevent bad actors from overriding repo configs with other keys. So if the
fingerprint is not stored yet, calculate it and store it. If the fingerprint
is stored, then check it against the calculated fingerprint just to make sure
it is correct. If the fingerprint is empty, then store the calculated one.

This was in place before, but it needed to be updated for the new Repo
ContentProvider.
---
 src/org/fdroid/fdroid/data/RepoProvider.java | 37 +++++++++++++++-----
 1 file changed, 28 insertions(+), 9 deletions(-)

diff --git a/src/org/fdroid/fdroid/data/RepoProvider.java b/src/org/fdroid/fdroid/data/RepoProvider.java
index 8232d7cf9..3f955fd37 100644
--- a/src/org/fdroid/fdroid/data/RepoProvider.java
+++ b/src/org/fdroid/fdroid/data/RepoProvider.java
@@ -15,6 +15,7 @@ import java.util.List;
 public class RepoProvider extends FDroidProvider {
 
     public static final class Helper {
+        public static final String TAG = "RepoProvider.Helper";
 
         private Helper() {}
 
@@ -91,16 +92,34 @@ public class RepoProvider extends FDroidProvider {
                 values.put(DataColumns.NAME, name);
             }
 
-            // Recalculate the fingerprint if we are saving a public key (it is
-            // probably a new public key. If not, we will get the same
-            // fingerprint anyhow).
-            if (values.containsKey(DataColumns.PUBLIC_KEY) &&
-                    values.containsKey(DataColumns.FINGERPRINT)) {
-
+            /*
+             * If the repo is signed and has a public key, then guarantee that
+             * the fingerprint is also set. The stored fingerprint is checked
+             * when a repo URI is received by FDroid to prevent bad actors from
+             * overriding repo configs with other keys. So if the fingerprint is
+             * not stored yet, calculate it and store it. If the fingerprint is
+             * stored, then check it against the calculated fingerprint just to
+             * make sure it is correct. If the fingerprint is empty, then store
+             * the calculated one.
+             */
+            if (values.containsKey(DataColumns.PUBLIC_KEY)) {
                 String publicKey = values.getAsString(DataColumns.PUBLIC_KEY);
-                String fingerprint = values.getAsString(DataColumns.FINGERPRINT);
-                if (publicKey != null && fingerprint == null) {
-                    values.put(DataColumns.FINGERPRINT, DB.calcFingerprint(publicKey));
+                String calcedFingerprint = DB.calcFingerprint(publicKey);
+                if (values.containsKey(DataColumns.FINGERPRINT)) {
+                    String fingerprint = values.getAsString(DataColumns.FINGERPRINT);
+                    if (!TextUtils.isEmpty(publicKey)) {
+                        if (TextUtils.isEmpty(fingerprint)) {
+                            values.put(DataColumns.FINGERPRINT, calcedFingerprint);
+                        } else if (!fingerprint.equals(calcedFingerprint)) {
+                            // TODO the UI should represent this error!
+                            Log.e(TAG, "The stored and calculated fingerprints do not match!");
+                            Log.e(TAG, "stored: " + fingerprint);
+                            Log.e(TAG, "calced: " + calcedFingerprint);
+                        }
+                    }
+                } else if (!TextUtils.isEmpty(publicKey)) {
+                    // no fingerprint in 'values', so put one there
+                    values.put(DataColumns.FINGERPRINT, calcedFingerprint);
                 }
             }