Reuse signature creation timestamp for synchronous signing

3 files changed, 44 insertions, 33 deletions

diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpSignEncrypt.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpSignEncrypt.java
index cc34e8737..41b81bf1c 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpSignEncrypt.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpSignEncrypt.java
@@ -18,10 +18,8 @@
 
 package org.sufficientlysecure.keychain.pgp;
 
-import org.openkeychain.nfc.NfcHandler;
 import org.spongycastle.bcpg.ArmoredOutputStream;
 import org.spongycastle.bcpg.BCPGOutputStream;
-import org.spongycastle.bcpg.S2K;
 import org.spongycastle.openpgp.PGPCompressedDataGenerator;
 import org.spongycastle.openpgp.PGPEncryptedDataGenerator;
 import org.spongycastle.openpgp.PGPException;
@@ -41,17 +39,14 @@ import org.sufficientlysecure.keychain.util.InputData;
 import org.sufficientlysecure.keychain.util.Log;
 
 import java.io.BufferedReader;
-import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.io.UnsupportedEncodingException;
-import java.nio.charset.Charset;
 import java.security.NoSuchAlgorithmException;
 import java.security.NoSuchProviderException;
 import java.security.SignatureException;
-import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Date;
 import java.util.LinkedList;
@@ -77,7 +72,9 @@ public class PgpSignEncrypt {
     private String mSignaturePassphrase;
     private boolean mEncryptToSigner;
     private boolean mCleartextInput;
-    private byte[] mNfcData;
+
+    private byte[] mNfcSignedHash = null;
+    private Date mNfcCreationTimestamp = null;
 
     private static byte[] NEW_LINE;
 
@@ -108,7 +105,8 @@ public class PgpSignEncrypt {
         this.mSignaturePassphrase = builder.mSignaturePassphrase;
         this.mEncryptToSigner = builder.mEncryptToSigner;
         this.mCleartextInput = builder.mCleartextInput;
-        this.mNfcData = builder.mNfcData;
+        this.mNfcSignedHash = builder.mNfcSignedHash;
+        this.mNfcCreationTimestamp = builder.mNfcCreationTimestamp;
     }
 
     public static class Builder {
@@ -131,7 +129,9 @@ public class PgpSignEncrypt {
         private String mSignaturePassphrase = null;
         private boolean mEncryptToSigner = false;
         private boolean mCleartextInput = false;
-        private byte[] mNfcData = null;
+
+        private byte[] mNfcSignedHash = null;
+        private Date mNfcCreationTimestamp = null;
 
         public Builder(ProviderHelper providerHelper, String versionHeader, InputData data, OutputStream outStream) {
             this.mProviderHelper = providerHelper;
@@ -216,8 +216,9 @@ public class PgpSignEncrypt {
             return this;
         }
 
-        public Builder setNfcData(byte[] nfcData) {
-            mNfcData = nfcData;
+        public Builder setNfcState(byte[] signedHash, Date creationTimestamp) {
+            mNfcSignedHash = signedHash;
+            mNfcCreationTimestamp = creationTimestamp;
             return this;
         }
 
@@ -259,19 +260,15 @@ public class PgpSignEncrypt {
     }
 
     public static class NeedNfcDataException extends Exception {
-        public byte[] mData;
+        public byte[] mHashToSign;
+        public Date mCreationTimestamp;
 
-        public NeedNfcDataException(byte[] data) {
-            mData = data;
+        public NeedNfcDataException(byte[] hashToSign, Date creationTimestamp) {
+            mHashToSign = hashToSign;
+            mCreationTimestamp = creationTimestamp;
         }
     }
 
-    // TODO: remove later
-    static String convertStreamToString(java.io.InputStream is) {
-        java.util.Scanner s = new java.util.Scanner(is).useDelimiter("\\A");
-        return s.hasNext() ? s.next() : "";
-    }
-
     /**
      * Signs and/or encrypts data based on parameters of class
      */
@@ -381,7 +378,7 @@ public class PgpSignEncrypt {
                             mSignatureHashAlgorithm, cleartext);
                 } else {
                     signatureGenerator = signingKey.getSignatureGenerator(
-                            mSignatureHashAlgorithm, cleartext, mNfcData);
+                            mSignatureHashAlgorithm, cleartext, mNfcSignedHash, mNfcCreationTimestamp);
                 }
             } catch (PgpGeneralException e) {
                 // TODO throw correct type of exception (which shouldn't be PGPException)
@@ -546,8 +543,8 @@ public class PgpSignEncrypt {
                 try {
                     signatureGenerator.generate().encode(pOut);
                 } catch (NfcSyncPGPContentSignerBuilder.NfcInteractionNeeded e) {
-                    // this secret key diverts to a OpenPGP card, throw exception with to-be-signed hash
-                    throw new NeedNfcDataException(e.hashToSign);
+                    // this secret key diverts to a OpenPGP card, throw exception with hash that will be signed
+                    throw new NeedNfcDataException(e.hashToSign, e.creationTimestamp);
                 }
             }
         }
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/WrappedSecretKey.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/WrappedSecretKey.java
index 141f2d5eb..ea919b683 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/WrappedSecretKey.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/WrappedSecretKey.java
@@ -1,7 +1,6 @@
 package org.sufficientlysecure.keychain.pgp;
 
 import org.spongycastle.bcpg.HashAlgorithmTags;
-import org.spongycastle.bcpg.PublicKeyAlgorithmTags;
 import org.spongycastle.bcpg.S2K;
 import org.spongycastle.openpgp.PGPException;
 import org.spongycastle.openpgp.PGPPrivateKey;
@@ -30,11 +29,9 @@ import org.sufficientlysecure.keychain.util.Log;
 import java.security.NoSuchAlgorithmException;
 import java.security.NoSuchProviderException;
 import java.security.SignatureException;
-import java.util.ArrayList;
-import java.util.HashSet;
+import java.util.Date;
 import java.util.LinkedList;
 import java.util.List;
-import java.util.Set;
 
 /** Wrapper for a PGPSecretKey.
  *
@@ -121,7 +118,7 @@ public class WrappedSecretKey extends WrappedPublicKey {
     }
 
     public PGPSignatureGenerator getSignatureGenerator(int hashAlgo, boolean cleartext,
-                                                       byte[] nfcSignedHash)
+                                                       byte[] nfcSignedHash, Date nfcCreationTimestamp)
             throws PgpGeneralException {
         if (mPrivateKeyState == PRIVATE_KEY_STATE_LOCKED) {
             throw new PrivateKeyNotUnlockedException();
@@ -129,11 +126,21 @@ public class WrappedSecretKey extends WrappedPublicKey {
 
         PGPContentSignerBuilder contentSignerBuilder;
         if (mPrivateKeyState == PRIVATE_KEY_STATE_DIVERT_TO_CARD) {
+            // to sign using nfc PgpSignEncrypt is executed two times.
+            // the first time it stops to return the PendingIntent for nfc connection and signing the hash
+            // the second time the signed hash is used.
+            // to get the same hash we cache the timestamp for the second round!
+            if (nfcCreationTimestamp == null) {
+                nfcCreationTimestamp = new Date();
+            }
+
             // use synchronous "NFC based" SignerBuilder
             contentSignerBuilder = new NfcSyncPGPContentSignerBuilder(
                     mSecretKey.getPublicKey().getAlgorithm(), hashAlgo,
-                    mSecretKey.getKeyID(), nfcSignedHash)
+                    mSecretKey.getKeyID(), nfcSignedHash, nfcCreationTimestamp)
                     .setProvider(Constants.BOUNCY_CASTLE_PROVIDER_NAME);
+
+            Log.d(Constants.TAG, "mSecretKey.getKeyID() "+ PgpKeyHelper.convertKeyIdToHex(mSecretKey.getKeyID()));
         } else {
             // content signer based on signing key algorithm and chosen hash algorithm
             contentSignerBuilder = new JcaPGPContentSignerBuilder(
@@ -155,6 +162,10 @@ public class WrappedSecretKey extends WrappedPublicKey {
 
             PGPSignatureSubpacketGenerator spGen = new PGPSignatureSubpacketGenerator();
             spGen.setSignerUserID(false, mRing.getPrimaryUserIdWithFallback());
+            if (nfcCreationTimestamp != null) {
+                spGen.setSignatureCreationTime(false, nfcCreationTimestamp);
+                Log.d(Constants.TAG, "For NFC: set sig creation time to " + nfcCreationTimestamp);
+            }
             signatureGenerator.setHashedSubpackets(spGen.generate());
             return signatureGenerator;
         } catch(PGPException e) {
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/remote/OpenPgpService.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/remote/OpenPgpService.java
index a00759180..e18af2eda 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/remote/OpenPgpService.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/remote/OpenPgpService.java
@@ -50,6 +50,7 @@ import org.sufficientlysecure.keychain.util.Log;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.util.ArrayList;
+import java.util.Date;
 import java.util.Set;
 
 public class OpenPgpService extends RemoteService {
@@ -136,11 +137,11 @@ public class OpenPgpService extends RemoteService {
         return result;
     }
 
-    private Intent getNfcIntent(Intent data, byte[] in) {
+    private Intent getNfcIntent(Intent data, byte[] hashToSign) {
         // build PendingIntent for Yubikey NFC operations
         Intent intent = new Intent(getBaseContext(), NfcActivity.class);
         intent.setAction(NfcActivity.ACTION_SIGN_HASH);
-        intent.putExtra(NfcActivity.EXTRA_NFC_DATA, in);
+        intent.putExtra(NfcActivity.EXTRA_NFC_HASH_TO_SIGN, hashToSign);
         intent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP | Intent.FLAG_ACTIVITY_CLEAR_TOP);
         // pass params through to activity that it can be returned again later to repeat pgp operation
         intent.putExtra(NfcActivity.EXTRA_DATA, data);
@@ -191,7 +192,8 @@ public class OpenPgpService extends RemoteService {
                 return passphraseBundle;
             }
 
-            byte[] nfcData = data.getByteArrayExtra(OpenPgpApi.EXTRA_NFC_DATA);
+            byte[] nfcSignedHash = data.getByteArrayExtra(OpenPgpApi.EXTRA_NFC_SIGNED_HASH);
+            Date nfcCreationTimestamp = new Date(data.getLongExtra(OpenPgpApi.EXTRA_NFC_SIG_CREATION_TIMESTAMP, 0));
 
             // Get Input- and OutputStream from ParcelFileDescriptor
             InputStream is = new ParcelFileDescriptor.AutoCloseInputStream(input);
@@ -210,7 +212,7 @@ public class OpenPgpService extends RemoteService {
                         .setSignatureForceV3(false)
                         .setSignatureMasterKeyId(accSettings.getKeyId())
                         .setSignaturePassphrase(passphrase)
-                        .setNfcData(nfcData);
+                        .setNfcState(nfcSignedHash, nfcCreationTimestamp);
 
                 // TODO: currently always assume cleartext input, no sign-only of binary currently!
                 builder.setCleartextInput(true);
@@ -229,7 +231,8 @@ public class OpenPgpService extends RemoteService {
                     throw new Exception(getString(R.string.error_no_signature_key));
                 } catch (PgpSignEncrypt.NeedNfcDataException e) {
                     // return PendingIntent to execute NFC activity
-                    Intent nfcIntent = getNfcIntent(data, e.mData);
+                    data.putExtra(OpenPgpApi.EXTRA_NFC_SIG_CREATION_TIMESTAMP, e.mCreationTimestamp.getTime());
+                    Intent nfcIntent = getNfcIntent(data, e.mHashToSign);
                     return nfcIntent;
                 }
             } finally {