add diffKeyrings method

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/testsupport/KeyringTestingHelper.java

@@ -2,12 +2,18 @@ package org.sufficientlysecure.keychain.testsupport;
 
 import android.content.Context;
 
+import org.spongycastle.util.Arrays;
 import org.sufficientlysecure.keychain.pgp.NullProgressable;
 import org.sufficientlysecure.keychain.pgp.UncachedKeyRing;
 import org.sufficientlysecure.keychain.provider.ProviderHelper;
 import org.sufficientlysecure.keychain.service.OperationResults;
 
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
 import java.util.Collection;
+import java.util.HashSet;
+import java.util.Set;
 
 /**
  * Helper for tests of the Keyring import in ProviderHelper.
@@ -44,6 +50,132 @@ public class KeyringTestingHelper {
         return saveSuccess;
     }
 
+    public static class Packet {
+        int tag;
+        int length;
+        byte[] buf;
+
+        public boolean equals(Object other) {
+            return other instanceof Packet && Arrays.areEqual(this.buf, ((Packet) other).buf);
+        }
+
+        public int hashCode() {
+            System.out.println("tag: " + tag + ", code: " + Arrays.hashCode(buf));
+            return Arrays.hashCode(buf);
+        }
+    }
+
+    public static boolean diffKeyrings(byte[] ringA, byte[] ringB, Set<Packet> onlyA, Set<Packet> onlyB)
+            throws IOException {
+        InputStream streamA = new ByteArrayInputStream(ringA);
+        InputStream streamB = new ByteArrayInputStream(ringB);
+
+        HashSet<Packet> a = new HashSet<Packet>(), b = new HashSet<Packet>();
+
+        Packet p;
+        while(true) {
+            p = readPacket(streamA);
+            if (p == null) {
+                break;
+            }
+            a.add(p);
+        }
+        while(true) {
+            p = readPacket(streamB);
+            if (p == null) {
+                break;
+            }
+            b.add(p);
+        }
+
+        onlyA.addAll(a);
+        onlyA.removeAll(b);
+        onlyB.addAll(b);
+        onlyB.removeAll(a);
+
+        return onlyA.isEmpty() && onlyB.isEmpty();
+    }
+
+    private static Packet readPacket(InputStream in) throws IOException {
+
+        // save here. this is tag + length, max 6 bytes
+        in.mark(6);
+
+        int hdr = in.read();
+        int headerLength = 1;
+
+        if (hdr < 0) {
+            return null;
+        }
+
+        if ((hdr & 0x80) == 0) {
+            throw new IOException("invalid header encountered");
+        }
+
+        boolean newPacket = (hdr & 0x40) != 0;
+        int tag = 0;
+        int bodyLen = 0;
+
+        if (newPacket) {
+            tag = hdr & 0x3f;
+
+            int l = in.read();
+            headerLength += 1;
+
+            if (l < 192) {
+                bodyLen = l;
+            } else if (l <= 223) {
+                int b = in.read();
+                headerLength += 1;
+
+                bodyLen = ((l - 192) << 8) + (b) + 192;
+            } else if (l == 255) {
+                bodyLen = (in.read() << 24) | (in.read() << 16) | (in.read() << 8) | in.read();
+                headerLength += 4;
+            } else {
+                // bodyLen = 1 << (l & 0x1f);
+                throw new IOException("no support for partial bodies in test classes");
+            }
+        } else {
+            int lengthType = hdr & 0x3;
+
+            tag = (hdr & 0x3f) >> 2;
+
+            switch (lengthType) {
+                case 0:
+                    bodyLen = in.read();
+                    headerLength += 1;
+                    break;
+                case 1:
+                    bodyLen = (in.read() << 8) | in.read();
+                    headerLength += 2;
+                    break;
+                case 2:
+                    bodyLen = (in.read() << 24) | (in.read() << 16) | (in.read() << 8) | in.read();
+                    headerLength += 4;
+                    break;
+                case 3:
+                    // bodyLen = 1 << (l & 0x1f);
+                    throw new IOException("no support for partial bodies in test classes");
+                default:
+                    throw new IOException("unknown length type encountered");
+            }
+        }
+
+        in.reset();
+
+        // read the entire packet INCLUDING the header here
+        byte[] buf = new byte[headerLength+bodyLen];
+        if (in.read(buf) != headerLength+bodyLen) {
+            throw new IOException("read length mismatch!");
+        }
+        Packet p = new Packet();
+        p.tag = tag;
+        p.length = bodyLen;
+        p.buf = buf;
+        return p;
+
+    }
 
     private void retrieveKeyAndExpectNotFound(ProviderHelper providerHelper, long masterKeyId) {
         try {
@@ -53,4 +185,5 @@ public class KeyringTestingHelper {
             // good
         }
     }
+
 }