From 5cf07b4a039bb4b03ced54a9d3d939ec7c1cad7c Mon Sep 17 00:00:00 2001
From: Thialfihar <thialfihar@gmail.com>
Date: Thu, 29 Apr 2010 01:38:19 +0000
Subject: [PATCH] only allow asymmetric encryption or symmetric encryption of
 files, not both like before

---
 src/org/thialfihar/android/apg/Apg.java       | 16 +++++++++++++++-
 .../android/apg/DecryptFileActivity.java      | 19 ++++++++++++-------
 .../android/apg/DecryptMessageActivity.java   |  2 ++
 3 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/src/org/thialfihar/android/apg/Apg.java b/src/org/thialfihar/android/apg/Apg.java
index 31720c5af..af4cbf1ed 100644
--- a/src/org/thialfihar/android/apg/Apg.java
+++ b/src/org/thialfihar/android/apg/Apg.java
@@ -166,6 +166,14 @@ public class Apg {
         }
     }
 
+    public static class NoAsymmetricEncryptionException extends Exception {
+        static final long serialVersionUID = 0xf812773343L;
+
+        public NoAsymmetricEncryptionException() {
+            super();
+        }
+    }
+
     static {
         mPublicKeyRings = new Vector<PGPPublicKeyRing>();
         mSecretKeyRings = new Vector<PGPSecretKeyRing>();
@@ -1366,7 +1374,7 @@ public class Apg {
     }
 
     public static long getDecryptionKeyId(InputStream inStream)
-            throws GeneralException, IOException {
+            throws GeneralException, NoAsymmetricEncryptionException, IOException {
         InputStream in = PGPUtil.getDecoderStream(inStream);
         PGPObjectFactory pgpF = new PGPObjectFactory(in);
         PGPEncryptedDataList enc;
@@ -1387,9 +1395,11 @@ public class Apg {
         // 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 = findSecretKey(pbe.getKeyID());
                 if (secretKey != null) {
@@ -1398,6 +1408,10 @@ public class Apg {
             }
         }
 
+        if (!gotAsymmetricEncryption) {
+            throw new NoAsymmetricEncryptionException();
+        }
+
         if (secretKey == null) {
             return 0;
         }
diff --git a/src/org/thialfihar/android/apg/DecryptFileActivity.java b/src/org/thialfihar/android/apg/DecryptFileActivity.java
index 8e21eae11..49f039423 100644
--- a/src/org/thialfihar/android/apg/DecryptFileActivity.java
+++ b/src/org/thialfihar/android/apg/DecryptFileActivity.java
@@ -129,18 +129,23 @@ public class DecryptFileActivity extends BaseActivity {
 
         try {
             InputStream in = new FileInputStream(mInputFilename);
-            setSecretKeyId(Apg.getDecryptionKeyId(in));
-            if (getSecretKeyId() == 0) {
+            try {
+                setSecretKeyId(Apg.getDecryptionKeyId(in));
+                if (getSecretKeyId() == 0) {
+                    throw new Apg.GeneralException("no suitable keys found");
+                }
+                mAssumeSymmetricEncryption = false;
+            } catch (Apg.NoAsymmetricEncryptionException e) {
+                setSecretKeyId(0);
                 // reopen the file to check whether there's symmetric encryption data in there
                 in = new FileInputStream(mInputFilename);
                 if (!Apg.hasSymmetricEncryption(in)) {
-                    throw new Apg.GeneralException("no suitable keys found");
+                    throw new Apg.GeneralException("no known kind of encryption found");
                 }
                 mAssumeSymmetricEncryption = true;
-            } else {
-                mAssumeSymmetricEncryption = false;
-            }
-            showDialog(Id.dialog.pass_phrase);
+           }
+
+           showDialog(Id.dialog.pass_phrase);
         } catch (FileNotFoundException e) {
             error = "file not found: " + e.getLocalizedMessage();
         } catch (IOException e) {
diff --git a/src/org/thialfihar/android/apg/DecryptMessageActivity.java b/src/org/thialfihar/android/apg/DecryptMessageActivity.java
index d3a84eff5..76589016f 100644
--- a/src/org/thialfihar/android/apg/DecryptMessageActivity.java
+++ b/src/org/thialfihar/android/apg/DecryptMessageActivity.java
@@ -155,6 +155,8 @@ public class DecryptMessageActivity extends BaseActivity {
             error = e.getLocalizedMessage();
         } catch (Apg.GeneralException e) {
             error = e.getLocalizedMessage();
+        } catch (Apg.NoAsymmetricEncryptionException e) {
+            error = "no asymmetric encryption found";
         }
         if (error != null) {
             Toast.makeText(this, "Error: " + error, Toast.LENGTH_SHORT).show();