ElGamal support added, fix of some minor GUI bugs, added a bunch of safe primes for ElGamal key creation

7 files changed, 287 insertions, 40 deletions

diff --git a/src/org/thialfihar/android/apg/Apg.java b/src/org/thialfihar/android/apg/Apg.java
index df0911814..4257c2afb 100644
--- a/src/org/thialfihar/android/apg/Apg.java
+++ b/src/org/thialfihar/android/apg/Apg.java
@@ -277,7 +277,8 @@ public class Apg {
         return mPassPhrase;

     }

 

-    public static PGPSecretKey createKey(int algorithmChoice, int keySize, String passPhrase)

+    public static PGPSecretKey createKey(int algorithmChoice, int keySize, String passPhrase,

+                                         PGPSecretKey masterKey)

                   throws NoSuchAlgorithmException, PGPException, NoSuchProviderException,

                   GeneralException, InvalidAlgorithmParameterException {

 

@@ -303,21 +304,17 @@ public class Apg {
             }

 

             case Id.choice.algorithm.elgamal: {

-                if (keySize != 2048) {

-                    throw new GeneralException("ElGamal currently requires 2048bit");

+                if (masterKey == null) {

+                    throw new GeneralException("The master key cannot be an ElGamal key.");

                 }

                 keyGen = KeyPairGenerator.getInstance("ELGAMAL", new BouncyCastleProvider());

-                BigInteger p = new BigInteger(

-                "36F0255DDE973DCB3B399D747F23E32ED6FDB1F77598338BFDF44159C4EC64DDAEB5F78671CBFB22" +

-                "106AE64C32C5BCE4CFD4F5920DA0EBC8B01ECA9292AE3DBA1B7A4A899DA181390BB3BD1659C81294" +

-                "F400A3490BF9481211C79404A576605A5160DBEE83B4E019B6D799AE131BA4C23DFF83475E9C40FA" +

-                "6725B7C9E3AA2C6596E9C05702DB30A07C9AA2DC235C5269E39D0CA9DF7AAD44612AD6F88F696992" +

-                "98F3CAB1B54367FB0E8B93F735E7DE83CD6FA1B9D1C931C41C6188D3E7F179FC64D87C5D13F85D70" +

-                "4A3AA20F90B3AD3621D434096AA7E8E7C66AB683156A951AEA2DD9E76705FAEFEA8D71A575535597" +

-                "0000000000000001", 16);

-                ElGamalParameterSpec elParams = new ElGamalParameterSpec(p, new BigInteger("2"));

+                BigInteger p = Primes.getBestPrime(keySize);

+                BigInteger g = new BigInteger("2");

+

+                ElGamalParameterSpec elParams = new ElGamalParameterSpec(p, g);

+

                 keyGen.initialize(elParams);

-                algorithm = PGPPublicKey.ELGAMAL_GENERAL;

+                algorithm = PGPPublicKey.ELGAMAL_ENCRYPT;

                 break;

             }

 

@@ -336,11 +333,39 @@ public class Apg {
 

         PGPKeyPair keyPair = new PGPKeyPair(algorithm, keyGen.generateKeyPair(), new Date());

 

-        // enough for now, as we assemble the key again later anyway

-        PGPSecretKey secretKey =

-                new PGPSecretKey(PGPSignature.DEFAULT_CERTIFICATION, keyPair, "",

-                                 PGPEncryptedData.CAST5, passPhrase.toCharArray(), null, null,

-                                 new SecureRandom(), new BouncyCastleProvider().getName());

+        PGPSecretKey secretKey = null;

+        if (masterKey == null) {

+            // enough for now, as we assemble the key again later anyway

+            secretKey = new PGPSecretKey(PGPSignature.DEFAULT_CERTIFICATION, keyPair, "",

+                                         PGPEncryptedData.CAST5, passPhrase.toCharArray(),

+                                         null, null,

+                                         new SecureRandom(), new BouncyCastleProvider().getName());

+

+        } else {

+            PGPPublicKey tmpKey = masterKey.getPublicKey();

+            PGPPublicKey masterPublicKey =

+                new PGPPublicKey(tmpKey.getAlgorithm(),

+                                 tmpKey.getKey(new BouncyCastleProvider()),

+                                 tmpKey.getCreationTime());

+            PGPPrivateKey masterPrivateKey =

+                masterKey.extractPrivateKey(passPhrase.toCharArray(),

+                                            new BouncyCastleProvider());

+

+            PGPKeyPair masterKeyPair = new PGPKeyPair(masterPublicKey, masterPrivateKey);

+            PGPKeyRingGenerator ringGen =

+                new PGPKeyRingGenerator(PGPSignature.POSITIVE_CERTIFICATION,

+                                        masterKeyPair, "",

+                                        PGPEncryptedData.CAST5, passPhrase.toCharArray(),

+                                        null, null,

+                                        new SecureRandom(), new BouncyCastleProvider().getName());

+            ringGen.addSubKey(keyPair);

+            PGPSecretKeyRing secKeyRing = ringGen.generateSecretKeyRing();

+            Iterator it = secKeyRing.getSecretKeys();

+            // first one is the master key

+            it.next();

+            secretKey = (PGPSecretKey) it.next();

+        }

+

 

         return secretKey;

     }

@@ -490,7 +515,7 @@ public class Apg {
 

         progress.setProgress("building master key ring...", 30, 100);

         PGPKeyRingGenerator keyGen =

-                new PGPKeyRingGenerator(PGPSignature.DEFAULT_CERTIFICATION,

+                new PGPKeyRingGenerator(PGPSignature.POSITIVE_CERTIFICATION,

                                         masterKeyPair, mainUserId,

                                         PGPEncryptedData.CAST5, newPassPhrase.toCharArray(),

                                         hashedPacketsGen.generate(), unhashedPacketsGen.generate(),

diff --git a/src/org/thialfihar/android/apg/EditKeyActivity.java b/src/org/thialfihar/android/apg/EditKeyActivity.java
index 72c119246..b458c214e 100644
--- a/src/org/thialfihar/android/apg/EditKeyActivity.java
+++ b/src/org/thialfihar/android/apg/EditKeyActivity.java
@@ -72,7 +72,10 @@ public class EditKeyActivity extends BaseActivity implements OnClickListener {
         if (intent.getExtras() != null) {
             keyId = intent.getExtras().getLong("keyId");
         }
-        if (keyId != 0) {
+
+        if (keyId == 0) {
+            Apg.setPassPhrase(null);
+        } else {
             PGPSecretKey masterKey = null;
             mKeyRing = Apg.getSecretKeyRing(keyId);
             if (mKeyRing != null) {
diff --git a/src/org/thialfihar/android/apg/EncryptMessageActivity.java b/src/org/thialfihar/android/apg/EncryptMessageActivity.java
index e09ae9ade..c394fb45f 100644
--- a/src/org/thialfihar/android/apg/EncryptMessageActivity.java
+++ b/src/org/thialfihar/android/apg/EncryptMessageActivity.java
@@ -283,6 +283,14 @@ public class EncryptMessageActivity extends BaseActivity {
     @Override
     protected void onActivityResult(int requestCode, int resultCode, Intent data) {
         switch (requestCode) {
+            case Id.request.secret_keys: {
+                if (resultCode == RESULT_OK) {
+                    super.onActivityResult(requestCode, resultCode, data);
+                    updateView();
+                }
+                break;
+            }
+
             case Id.request.public_keys: {
                 if (resultCode == RESULT_OK) {
                     Bundle bundle = data.getExtras();
diff --git a/src/org/thialfihar/android/apg/MainActivity.java b/src/org/thialfihar/android/apg/MainActivity.java
index 33d79ecda..92e9bcfd2 100644
--- a/src/org/thialfihar/android/apg/MainActivity.java
+++ b/src/org/thialfihar/android/apg/MainActivity.java
@@ -222,6 +222,8 @@ public class MainActivity extends BaseActivity {
                 SpannableString info =
                         new SpannableString("Read the warnings!\n\n" +
                                             "Changes:\n" +
+                                            "* ElGamal subkey support\n" +
+                                            "* bug fixes\n" +
                                             "\n" +
                                             "WARNING: be careful editing your existing keys, as they " +
                                             "WILL be stripped of certificates right now.\n" +
diff --git a/src/org/thialfihar/android/apg/Primes.java b/src/org/thialfihar/android/apg/Primes.java
new file mode 100644
index 000000000..28ff732a2
--- /dev/null
+++ b/src/org/thialfihar/android/apg/Primes.java
@@ -0,0 +1,185 @@
+/*

+ * 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.thialfihar.android.apg;

+

+import java.math.BigInteger;

+

+public final class Primes {

+    // taken from http://www.ietf.org/rfc/rfc3526.txt

+    public static final String P1536 =

+            "FFFFFFFF FFFFFFFF C90FDAA2 2168C234 C4C6628B 80DC1CD1" +

+            "29024E08 8A67CC74 020BBEA6 3B139B22 514A0879 8E3404DD" +

+            "EF9519B3 CD3A431B 302B0A6D F25F1437 4FE1356D 6D51C245" +

+            "E485B576 625E7EC6 F44C42E9 A637ED6B 0BFF5CB6 F406B7ED" +

+            "EE386BFB 5A899FA5 AE9F2411 7C4B1FE6 49286651 ECE45B3D" +

+            "C2007CB8 A163BF05 98DA4836 1C55D39A 69163FA8 FD24CF5F" +

+            "83655D23 DCA3AD96 1C62F356 208552BB 9ED52907 7096966D" +

+            "670C354E 4ABC9804 F1746C08 CA237327 FFFFFFFF FFFFFFFF";

+

+    public static final String P2048 =

+            "FFFFFFFF FFFFFFFF C90FDAA2 2168C234 C4C6628B 80DC1CD1" +

+            "29024E08 8A67CC74 020BBEA6 3B139B22 514A0879 8E3404DD" +

+            "EF9519B3 CD3A431B 302B0A6D F25F1437 4FE1356D 6D51C245" +

+            "E485B576 625E7EC6 F44C42E9 A637ED6B 0BFF5CB6 F406B7ED" +

+            "EE386BFB 5A899FA5 AE9F2411 7C4B1FE6 49286651 ECE45B3D" +

+            "C2007CB8 A163BF05 98DA4836 1C55D39A 69163FA8 FD24CF5F" +

+            "83655D23 DCA3AD96 1C62F356 208552BB 9ED52907 7096966D" +

+            "670C354E 4ABC9804 F1746C08 CA18217C 32905E46 2E36CE3B" +

+            "E39E772C 180E8603 9B2783A2 EC07A28F B5C55DF0 6F4C52C9" +

+            "DE2BCBF6 95581718 3995497C EA956AE5 15D22618 98FA0510" +

+            "15728E5A 8AACAA68 FFFFFFFF FFFFFFFF";

+

+    public static final String P3072 =

+            "FFFFFFFF FFFFFFFF C90FDAA2 2168C234 C4C6628B 80DC1CD1" +

+            "29024E08 8A67CC74 020BBEA6 3B139B22 514A0879 8E3404DD" +

+            "EF9519B3 CD3A431B 302B0A6D F25F1437 4FE1356D 6D51C245" +

+            "E485B576 625E7EC6 F44C42E9 A637ED6B 0BFF5CB6 F406B7ED" +

+            "EE386BFB 5A899FA5 AE9F2411 7C4B1FE6 49286651 ECE45B3D" +

+            "C2007CB8 A163BF05 98DA4836 1C55D39A 69163FA8 FD24CF5F" +

+            "83655D23 DCA3AD96 1C62F356 208552BB 9ED52907 7096966D" +

+            "670C354E 4ABC9804 F1746C08 CA18217C 32905E46 2E36CE3B" +

+            "E39E772C 180E8603 9B2783A2 EC07A28F B5C55DF0 6F4C52C9" +

+            "DE2BCBF6 95581718 3995497C EA956AE5 15D22618 98FA0510" +

+            "15728E5A 8AAAC42D AD33170D 04507A33 A85521AB DF1CBA64" +

+            "ECFB8504 58DBEF0A 8AEA7157 5D060C7D B3970F85 A6E1E4C7" +

+            "ABF5AE8C DB0933D7 1E8C94E0 4A25619D CEE3D226 1AD2EE6B" +

+            "F12FFA06 D98A0864 D8760273 3EC86A64 521F2B18 177B200C" +

+            "BBE11757 7A615D6C 770988C0 BAD946E2 08E24FA0 74E5AB31" +

+            "43DB5BFC E0FD108E 4B82D120 A93AD2CA FFFFFFFF FFFFFFFF";

+

+    public static final String P4096 =

+            "FFFFFFFF FFFFFFFF C90FDAA2 2168C234 C4C6628B 80DC1CD1" +

+            "29024E08 8A67CC74 020BBEA6 3B139B22 514A0879 8E3404DD" +

+            "EF9519B3 CD3A431B 302B0A6D F25F1437 4FE1356D 6D51C245" +

+            "E485B576 625E7EC6 F44C42E9 A637ED6B 0BFF5CB6 F406B7ED" +

+            "EE386BFB 5A899FA5 AE9F2411 7C4B1FE6 49286651 ECE45B3D" +

+            "C2007CB8 A163BF05 98DA4836 1C55D39A 69163FA8 FD24CF5F" +

+            "83655D23 DCA3AD96 1C62F356 208552BB 9ED52907 7096966D" +

+            "670C354E 4ABC9804 F1746C08 CA18217C 32905E46 2E36CE3B" +

+            "E39E772C 180E8603 9B2783A2 EC07A28F B5C55DF0 6F4C52C9" +

+            "DE2BCBF6 95581718 3995497C EA956AE5 15D22618 98FA0510" +

+            "15728E5A 8AAAC42D AD33170D 04507A33 A85521AB DF1CBA64" +

+            "ECFB8504 58DBEF0A 8AEA7157 5D060C7D B3970F85 A6E1E4C7" +

+            "ABF5AE8C DB0933D7 1E8C94E0 4A25619D CEE3D226 1AD2EE6B" +

+            "F12FFA06 D98A0864 D8760273 3EC86A64 521F2B18 177B200C" +

+            "BBE11757 7A615D6C 770988C0 BAD946E2 08E24FA0 74E5AB31" +

+            "43DB5BFC E0FD108E 4B82D120 A9210801 1A723C12 A787E6D7" +

+            "88719A10 BDBA5B26 99C32718 6AF4E23C 1A946834 B6150BDA" +

+            "2583E9CA 2AD44CE8 DBBBC2DB 04DE8EF9 2E8EFC14 1FBECAA6" +

+            "287C5947 4E6BC05D 99B2964F A090C3A2 233BA186 515BE7ED" +

+            "1F612970 CEE2D7AF B81BDD76 2170481C D0069127 D5B05AA9" +

+            "93B4EA98 8D8FDDC1 86FFB7DC 90A6C08F 4DF435C9 34063199" +

+            "FFFFFFFF FFFFFFFF";

+

+    public static final String P6144 =

+            "FFFFFFFF FFFFFFFF C90FDAA2 2168C234 C4C6628B 80DC1CD1" +

+            "29024E08 8A67CC74 020BBEA6 3B139B22 514A0879 8E3404DD" +

+            "EF9519B3 CD3A431B 302B0A6D F25F1437 4FE1356D 6D51C245" +

+            "E485B576 625E7EC6 F44C42E9 A637ED6B 0BFF5CB6 F406B7ED" +

+            "EE386BFB 5A899FA5 AE9F2411 7C4B1FE6 49286651 ECE45B3D" +

+            "C2007CB8 A163BF05 98DA4836 1C55D39A 69163FA8 FD24CF5F" +

+            "83655D23 DCA3AD96 1C62F356 208552BB 9ED52907 7096966D" +

+            "670C354E 4ABC9804 F1746C08 CA18217C 32905E46 2E36CE3B" +

+            "E39E772C 180E8603 9B2783A2 EC07A28F B5C55DF0 6F4C52C9" +

+            "DE2BCBF6 95581718 3995497C EA956AE5 15D22618 98FA0510" +

+            "15728E5A 8AAAC42D AD33170D 04507A33 A85521AB DF1CBA64" +

+            "ECFB8504 58DBEF0A 8AEA7157 5D060C7D B3970F85 A6E1E4C7" +

+            "ABF5AE8C DB0933D7 1E8C94E0 4A25619D CEE3D226 1AD2EE6B" +

+            "F12FFA06 D98A0864 D8760273 3EC86A64 521F2B18 177B200C" +

+            "BBE11757 7A615D6C 770988C0 BAD946E2 08E24FA0 74E5AB31" +

+            "43DB5BFC E0FD108E 4B82D120 A9210801 1A723C12 A787E6D7" +

+            "88719A10 BDBA5B26 99C32718 6AF4E23C 1A946834 B6150BDA" +

+            "2583E9CA 2AD44CE8 DBBBC2DB 04DE8EF9 2E8EFC14 1FBECAA6" +

+            "287C5947 4E6BC05D 99B2964F A090C3A2 233BA186 515BE7ED" +

+            "1F612970 CEE2D7AF B81BDD76 2170481C D0069127 D5B05AA9" +

+            "93B4EA98 8D8FDDC1 86FFB7DC 90A6C08F 4DF435C9 34028492" +

+            "36C3FAB4 D27C7026 C1D4DCB2 602646DE C9751E76 3DBA37BD" +

+            "F8FF9406 AD9E530E E5DB382F 413001AE B06A53ED 9027D831" +

+            "179727B0 865A8918 DA3EDBEB CF9B14ED 44CE6CBA CED4BB1B" +

+            "DB7F1447 E6CC254B 33205151 2BD7AF42 6FB8F401 378CD2BF" +

+            "5983CA01 C64B92EC F032EA15 D1721D03 F482D7CE 6E74FEF6" +

+            "D55E702F 46980C82 B5A84031 900B1C9E 59E7C97F BEC7E8F3" +

+            "23A97A7E 36CC88BE 0F1D45B7 FF585AC5 4BD407B2 2B4154AA" +

+            "CC8F6D7E BF48E1D8 14CC5ED2 0F8037E0 A79715EE F29BE328" +

+            "06A1D58B B7C5DA76 F550AA3D 8A1FBFF0 EB19CCB1 A313D55C" +

+            "DA56C9EC 2EF29632 387FE8D7 6E3C0468 043E8F66 3F4860EE" +

+            "12BF2D5B 0B7474D6 E694F91E 6DCC4024 FFFFFFFF FFFFFFFF";

+

+    public static final String P8192 =

+            "FFFFFFFF FFFFFFFF C90FDAA2 2168C234 C4C6628B 80DC1CD1" +

+            "29024E08 8A67CC74 020BBEA6 3B139B22 514A0879 8E3404DD" +

+            "EF9519B3 CD3A431B 302B0A6D F25F1437 4FE1356D 6D51C245" +

+            "E485B576 625E7EC6 F44C42E9 A637ED6B 0BFF5CB6 F406B7ED" +

+            "EE386BFB 5A899FA5 AE9F2411 7C4B1FE6 49286651 ECE45B3D" +

+            "C2007CB8 A163BF05 98DA4836 1C55D39A 69163FA8 FD24CF5F" +

+            "83655D23 DCA3AD96 1C62F356 208552BB 9ED52907 7096966D" +

+            "670C354E 4ABC9804 F1746C08 CA18217C 32905E46 2E36CE3B" +

+            "E39E772C 180E8603 9B2783A2 EC07A28F B5C55DF0 6F4C52C9" +

+            "DE2BCBF6 95581718 3995497C EA956AE5 15D22618 98FA0510" +

+            "15728E5A 8AAAC42D AD33170D 04507A33 A85521AB DF1CBA64" +

+            "ECFB8504 58DBEF0A 8AEA7157 5D060C7D B3970F85 A6E1E4C7" +

+            "ABF5AE8C DB0933D7 1E8C94E0 4A25619D CEE3D226 1AD2EE6B" +

+            "F12FFA06 D98A0864 D8760273 3EC86A64 521F2B18 177B200C" +

+            "BBE11757 7A615D6C 770988C0 BAD946E2 08E24FA0 74E5AB31" +

+            "43DB5BFC E0FD108E 4B82D120 A9210801 1A723C12 A787E6D7" +

+            "88719A10 BDBA5B26 99C32718 6AF4E23C 1A946834 B6150BDA" +

+            "2583E9CA 2AD44CE8 DBBBC2DB 04DE8EF9 2E8EFC14 1FBECAA6" +

+            "287C5947 4E6BC05D 99B2964F A090C3A2 233BA186 515BE7ED" +

+            "1F612970 CEE2D7AF B81BDD76 2170481C D0069127 D5B05AA9" +

+            "93B4EA98 8D8FDDC1 86FFB7DC 90A6C08F 4DF435C9 34028492" +

+            "36C3FAB4 D27C7026 C1D4DCB2 602646DE C9751E76 3DBA37BD" +

+            "F8FF9406 AD9E530E E5DB382F 413001AE B06A53ED 9027D831" +

+            "179727B0 865A8918 DA3EDBEB CF9B14ED 44CE6CBA CED4BB1B" +

+            "DB7F1447 E6CC254B 33205151 2BD7AF42 6FB8F401 378CD2BF" +

+            "5983CA01 C64B92EC F032EA15 D1721D03 F482D7CE 6E74FEF6" +

+            "D55E702F 46980C82 B5A84031 900B1C9E 59E7C97F BEC7E8F3" +

+            "23A97A7E 36CC88BE 0F1D45B7 FF585AC5 4BD407B2 2B4154AA" +

+            "CC8F6D7E BF48E1D8 14CC5ED2 0F8037E0 A79715EE F29BE328" +

+            "06A1D58B B7C5DA76 F550AA3D 8A1FBFF0 EB19CCB1 A313D55C" +

+            "DA56C9EC 2EF29632 387FE8D7 6E3C0468 043E8F66 3F4860EE" +

+            "12BF2D5B 0B7474D6 E694F91E 6DBE1159 74A3926F 12FEE5E4" +

+            "38777CB6 A932DF8C D8BEC4D0 73B931BA 3BC832B6 8D9DD300" +

+            "741FA7BF 8AFC47ED 2576F693 6BA42466 3AAB639C 5AE4F568" +

+            "3423B474 2BF1C978 238F16CB E39D652D E3FDB8BE FC848AD9" +

+            "22222E04 A4037C07 13EB57A8 1A23F0C7 3473FC64 6CEA306B" +

+            "4BCBC886 2F8385DD FA9D4B7F A2C087E8 79683303 ED5BDD3A" +

+            "062B3CF5 B3A278A6 6D2A13F8 3F44F82D DF310EE0 74AB6A36" +

+            "4597E899 A0255DC1 64F31CC5 0846851D F9AB4819 5DED7EA1" +

+            "B1D510BD 7EE74D73 FAF36BC3 1ECFA268 359046F4 EB879F92" +

+            "4009438B 481C6CD7 889A002E D5EE382B C9190DA6 FC026E47" +

+            "9558E447 5677E9AA 9E3050E2 765694DF C81F56E8 80B96E71" +

+            "60C980DD 98EDD3DF FFFFFFFF FFFFFFFF";

+

+    public static BigInteger getBestPrime(int keySize) {

+        String primeString;

+        if (keySize >= 8192) {

+            primeString = P8192;

+        } else if (keySize >= 6144) {

+            primeString = P6144;

+        } else if (keySize >= 4096) {

+            primeString = P4096;

+        } else if (keySize >= 3072) {

+            primeString = P3072;

+        } else if (keySize >= 2048) {

+            primeString = P2048;

+        } else {

+            primeString = P1536;

+        }

+

+        return new BigInteger(primeString.replaceAll(" ", ""), 16);

+    }

+}

diff --git a/src/org/thialfihar/android/apg/ui/widget/KeyEditor.java b/src/org/thialfihar/android/apg/ui/widget/KeyEditor.java
index 2ec1dcc4d..c490686ea 100644
--- a/src/org/thialfihar/android/apg/ui/widget/KeyEditor.java
+++ b/src/org/thialfihar/android/apg/ui/widget/KeyEditor.java
@@ -22,6 +22,7 @@ import java.util.Date;
 import java.util.GregorianCalendar;

 import java.util.Vector;

 

+import org.bouncycastle2.openpgp.PGPPublicKey;

 import org.bouncycastle2.openpgp.PGPSecretKey;

 import org.thialfihar.android.apg.Apg;

 import org.thialfihar.android.apg.Id;

@@ -150,30 +151,42 @@ public class KeyEditor extends LinearLayout implements Editor, OnClickListener {
         mKeyId.setText(keyId1Str + " " + keyId2Str);

 

         Vector<Choice> choices = new Vector<Choice>();

-        choices.add(new Choice(Id.choice.usage.sign_only,

-                               getResources().getString(R.string.sign_only)));

+        boolean isElGamalKey = (key.getPublicKey().getAlgorithm() == PGPPublicKey.ELGAMAL_ENCRYPT);

+        if (!isElGamalKey) {

+            choices.add(new Choice(Id.choice.usage.sign_only,

+                                   getResources().getString(R.string.sign_only)));

+        }

         if (!mIsMasterKey) {

             choices.add(new Choice(Id.choice.usage.encrypt_only,

                                    getResources().getString(R.string.encrypt_only)));

         }

-        choices.add(new Choice(Id.choice.usage.sign_and_encrypt,

-                               getResources().getString(R.string.sign_and_encrypt)));

+        if (!isElGamalKey) {

+            choices.add(new Choice(Id.choice.usage.sign_and_encrypt,

+                                   getResources().getString(R.string.sign_and_encrypt)));

+        }

 

         ArrayAdapter<Choice> adapter =

                 new ArrayAdapter<Choice>(getContext(),

-                                                        android.R.layout.simple_spinner_item,

-                                                        choices);

+                                         android.R.layout.simple_spinner_item, choices);

         adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

         mUsage.setAdapter(adapter);

 

+        int selectId = 0;

         if (Apg.isEncryptionKey(key)) {

             if (Apg.isSigningKey(key)) {

-                mUsage.setSelection(2);

+                selectId = Id.choice.usage.sign_and_encrypt;

             } else {

-                mUsage.setSelection(1);

+                selectId = Id.choice.usage.encrypt_only;

             }

         } else {

-            mUsage.setSelection(0);

+            selectId = Id.choice.usage.sign_only;

+        }

+

+        for (int i = 0; i < choices.size(); ++i) {

+            if (choices.get(i).getId() == selectId) {

+                mUsage.setSelection(i);

+                break;

+            }

         }

 

         GregorianCalendar cal = new GregorianCalendar();

diff --git a/src/org/thialfihar/android/apg/ui/widget/SectionView.java b/src/org/thialfihar/android/apg/ui/widget/SectionView.java
index 5a9f47702..2cac2375b 100644
--- a/src/org/thialfihar/android/apg/ui/widget/SectionView.java
+++ b/src/org/thialfihar/android/apg/ui/widget/SectionView.java
@@ -181,16 +181,23 @@ public class SectionView extends LinearLayout implements OnClickListener, Editor
                 View view = mInflater.inflate(R.layout.create_key, null);

                 dialog.setView(view);

                 dialog.setTitle("Create Key");

+                dialog.setMessage("Note: only subkeys support ElGamal, and for ElGamal will use " +

+                                  "the next smallest keysize of 1536, 2048, 3072, 4096, or 8192.");

+

+                boolean wouldBeMasterKey = (mEditors.getChildCount() == 0);

 

                 final Spinner algorithm = (Spinner) view.findViewById(R.id.algorithm);

-                Choice choices[] = {

-                        new Choice(Id.choice.algorithm.dsa,

-                                   getResources().getString(R.string.dsa)),

-                        /*new Choice(Id.choice.algorithm.elgamal,

-                                   getResources().getString(R.string.elgamal)),*/

-                        new Choice(Id.choice.algorithm.rsa,

-                                   getResources().getString(R.string.rsa)),

-                };

+                Vector<Choice> choices = new Vector<Choice>();

+                choices.add(new Choice(Id.choice.algorithm.dsa,

+                                       getResources().getString(R.string.dsa)));

+                if (!wouldBeMasterKey) {

+                    choices.add(new Choice(Id.choice.algorithm.elgamal,

+                                           getResources().getString(R.string.elgamal)));

+                }

+

+                choices.add(new Choice(Id.choice.algorithm.rsa,

+                                       getResources().getString(R.string.rsa)));

+

                 ArrayAdapter<Choice> adapter =

                         new ArrayAdapter<Choice>(getContext(),

                                                  android.R.layout.simple_spinner_item,

@@ -198,8 +205,8 @@ public class SectionView extends LinearLayout implements OnClickListener, Editor
                 adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

                 algorithm.setAdapter(adapter);

                 // make RSA the default

-                for (int i = 0; i < choices.length; ++i) {

-                    if (choices[i].getId() == Id.choice.algorithm.rsa) {

+                for (int i = 0; i < choices.size(); ++i) {

+                    if (choices.get(i).getId() == Id.choice.algorithm.rsa) {

                         algorithm.setSelection(i);

                         break;

                     }

@@ -294,8 +301,12 @@ public class SectionView extends LinearLayout implements OnClickListener, Editor
     public void run() {

         String error = null;

         try {

+            PGPSecretKey masterKey = null;

+            if (mEditors.getChildCount() > 0) {

+                masterKey = ((KeyEditor) mEditors.getChildAt(0)).getValue();

+            }

             mNewKey = Apg.createKey(mNewKeyAlgorithmChoice.getId(),

-                                    mNewKeySize, Apg.getPassPhrase());

+                                    mNewKeySize, Apg.getPassPhrase(), masterKey);

         } catch (NoSuchProviderException e) {

             error = e.getMessage();

         } catch (NoSuchAlgorithmException e) {