1 files changed, 121 insertions, 0 deletions
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/ComparableS2K.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/ComparableS2K.java
new file mode 100644
index 000000000..99b9cdab2
--- /dev/null
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/ComparableS2K.java
@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2016 Vincent Breitmoser <look@my.amazin.horse>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.sufficientlysecure.keychain.pgp;
+
+
+import java.util.Arrays;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+import org.bouncycastle.bcpg.S2K;
+
+
+/** This is an immutable and parcelable class which stores the full s2k parametrization
+ * of an encrypted secret key, i.e. all fields of the {@link S2K} class (type, hash algo,
+ * iteration count, iv) plus the encryptionAlgorithm. This class is intended to be used
+ * as key in a HashMap for session key caching purposes, and overrides the
+ * {@link #hashCode} and {@link #equals} methods in a suitable way.
+ *
+ * Note that although it is a rather unlikely scenario that secret keys of the same key
+ * are encrypted with different ciphers, the encryption algorithm still determines the
+ * length of the specific session key and thus needs to be considered for purposes of
+ * session key caching.
+ *
+ * @see org.bouncycastle.bcpg.S2K
+ */
+public class ComparableS2K implements Parcelable {
+
+    private final int encryptionAlgorithm;
+    private final int s2kType;
+    private final int s2kHashAlgo;
+    private final long s2kItCount;
+    private final byte[] s2kIV;
+
+    Integer cachedHashCode;
+
+    public ComparableS2K(int encryptionAlgorithm, S2K s2k) {
+        this.encryptionAlgorithm = encryptionAlgorithm;
+        this.s2kType = s2k.getType();
+        this.s2kHashAlgo = s2k.getHashAlgorithm();
+        this.s2kItCount = s2k.getIterationCount();
+        this.s2kIV = s2k.getIV();
+    }
+
+    protected ComparableS2K(Parcel in) {
+        encryptionAlgorithm = in.readInt();
+        s2kType = in.readInt();
+        s2kHashAlgo = in.readInt();
+        s2kItCount = in.readLong();
+        s2kIV = in.createByteArray();
+    }
+
+    @Override
+    public int hashCode() {
+        if (cachedHashCode == null) {
+            cachedHashCode = encryptionAlgorithm;
+            cachedHashCode = 31 * cachedHashCode + s2kType;
+            cachedHashCode = 31 * cachedHashCode + s2kHashAlgo;
+            cachedHashCode = 31 * cachedHashCode + (int) (s2kItCount ^ (s2kItCount >>> 32));
+            cachedHashCode = 31 * cachedHashCode + Arrays.hashCode(s2kIV);
+        }
+
+        return cachedHashCode;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        boolean isComparableS2K = o instanceof ComparableS2K;
+        if (!isComparableS2K) {
+            return false;
+        }
+        ComparableS2K other = (ComparableS2K) o;
+        return encryptionAlgorithm == other.encryptionAlgorithm
+                && s2kType == other.s2kType
+                && s2kHashAlgo == other.s2kHashAlgo
+                && s2kItCount == other.s2kItCount
+                && Arrays.equals(s2kIV, other.s2kIV);
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {
+        dest.writeInt(encryptionAlgorithm);
+        dest.writeInt(s2kType);
+        dest.writeInt(s2kHashAlgo);
+        dest.writeLong(s2kItCount);
+        dest.writeByteArray(s2kIV);
+    }
+
+    public static final Creator<ComparableS2K> CREATOR = new Creator<ComparableS2K>() {
+        @Override
+        public ComparableS2K createFromParcel(Parcel in) {
+            return new ComparableS2K(in);
+        }
+
+        @Override
+        public ComparableS2K[] newArray(int size) {
+            return new ComparableS2K[size];
+        }
+    };
+
+}