Http.abort: leave responses that were read to the end alone

Their connection is back in the pool and may be carrying another request by then (in Plexamp Lite this cut
read-ahead downloads short). From Plexamp Lite 1.14.1.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

net/AssetRoots.java

@@ -4,35 +4,47 @@ import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 
 import android.content.Context;
 
-/** Mozilla roots shipped as assets/roots/<sha1(subject)>-<n>.der */
+/**
+ * Mozilla roots shipped as assets/roots/<sha1(subject)>-<n>.der
+ *
+ * Roots are read from the APK once and kept: an app installed on the SD card loses its APK while the
+ * card is shared over USB, and a failed read must not leave every server "untrusted" until a restart.
+ */
 public final class AssetRoots implements CertVerifier.RootStore {
     private final Context ctx;
-    private Set<String> names;
+    private Set<String> names;                                                  // asset file names, once listed
+    private final Map<String, List<byte[]>> found = new HashMap<String, List<byte[]>>(); // by subject hash; null = none
 
     public AssetRoots(Context c) { ctx = c.getApplicationContext(); }
 
     public synchronized List<byte[]> find(byte[] subjectDer) {
+        String h = CertVerifier.sha1Hex(subjectDer);
+        if (found.containsKey(h)) return found.get(h);
         try {
             if (names == null) {
-                names = new HashSet<String>();
                 String[] l = ctx.getAssets().list("roots");
-                if (l != null) for (int i = 0; i < l.length; i++) names.add(l[i]);
+                if (l == null || l.length == 0) return null; // APK unreadable right now: try again next time
+                Set<String> n = new HashSet<String>();
+                for (int i = 0; i < l.length; i++) n.add(l[i]);
+                names = n;
             }
-            String h = CertVerifier.sha1Hex(subjectDer);
             List<byte[]> out = null;
             for (int i = 0; names.contains(h + "-" + i + ".der"); i++) {
                 if (out == null) out = new ArrayList<byte[]>();
                 out.add(readAll(ctx.getAssets().open("roots/" + h + "-" + i + ".der")));
             }
+            found.put(h, out);
             return out;
         } catch (IOException e) {
-            return null;
+            return null; // not cached: the next handshake reads again
         }
     }
 

net/Http.java

@@ -451,19 +451,25 @@ public final class Http {
     // ------------------------------------------------------------------ body streams
 
     private static final class FixedStream extends InputStream {
-        private final Conn c; private long left; private final boolean keepAlive; private boolean closed;
+        private final Conn c; private long left; private final boolean keepAlive; private volatile boolean closed;
 
         FixedStream(Conn c, long len, boolean keepAlive) {
             this.c = c; this.left = len; this.keepAlive = keepAlive;
             if (len == 0) finish(true);
         }
 
-        private void finish(boolean complete) {
+        private synchronized void finish(boolean complete) {
             if (closed) return;
             closed = true;
             if (complete && keepAlive) release(c); else c.close();
         }
 
+        synchronized void abort() {
+            if (closed) return;   // done: the connection may already be back in the pool, serving someone else
+            closed = true;
+            try { c.socket.close(); } catch (Exception ignored) {}
+        }
+
         @Override public int read() throws IOException {
             byte[] one = new byte[1];
             int n = read(one, 0, 1);
@@ -490,16 +496,22 @@ public final class Http {
 
     private static final class ChunkedStream extends InputStream {
         private final Conn c; private final boolean keepAlive;
-        private long chunkLeft = 0; private boolean eof; private boolean closed;
+        private long chunkLeft = 0; private boolean eof; private volatile boolean closed;
 
         ChunkedStream(Conn c, boolean keepAlive) { this.c = c; this.keepAlive = keepAlive; }
 
-        private void finish(boolean complete) {
+        private synchronized void finish(boolean complete) {
             if (closed) return;
             closed = true;
             if (complete && keepAlive) release(c); else c.close();
         }
 
+        synchronized void abort() {
+            if (closed) return;   // done: the connection may already be back in the pool, serving someone else
+            closed = true;
+            try { c.socket.close(); } catch (Exception ignored) {}
+        }
+
         private boolean nextChunk() throws IOException {
             if (eof) return false;
             String line = readLine(c.in);
@@ -551,7 +563,7 @@ public final class Http {
     }
 
     private static final class EofStream extends InputStream {
-        private final Conn c; private boolean closed;
+        private final Conn c; private volatile boolean closed;
         EofStream(Conn c) { this.c = c; }
 
         @Override public int read() throws IOException {
@@ -568,21 +580,25 @@ public final class Http {
             return n;
         }
 
-        @Override public void close() {
+        @Override public synchronized void close() {
             if (!closed) { closed = true; c.close(); }
         }
-    }
 
-    /** Close one in-flight response's socket from another thread (used to abort streams). */
-    public static void abort(Response r) {
-        if (r == null) return;
-        InputStream b = r.body;
-        Conn c = null;
-        if (b instanceof FixedStream) c = ((FixedStream) b).c;
-        else if (b instanceof ChunkedStream) c = ((ChunkedStream) b).c;
-        else if (b instanceof EofStream) c = ((EofStream) b).c;
-        if (c != null) {
+        synchronized void abort() {
+            if (closed) return;
+            closed = true;
             try { c.socket.close(); } catch (Exception ignored) {}
         }
     }
+
+    /** Close one in-flight response's socket from another thread (used to abort streams). A response that has
+     *  already been read to the end is left alone: its connection went back to the pool and may be carrying
+     *  another request by now (closing it cut read-ahead downloads short: "Unexpected end of stream"). */
+    public static void abort(Response r) {
+        if (r == null) return;
+        InputStream b = r.body;
+        if (b instanceof FixedStream) ((FixedStream) b).abort();
+        else if (b instanceof ChunkedStream) ((ChunkedStream) b).abort();
+        else if (b instanceof EofStream) ((EofStream) b).abort();
+    }
 }

spec.md

@@ -0,0 +1,41 @@
+# tlskit — spec
+
+The short contract for working on the shared HTTP/TLS client. `README.md` explains its use; this file says
+what it promises to the apps that copy it.
+
+## Goal
+
+Let Android 2.2/2.3 apps reach modern `https://` servers (TLS 1.2, today's roots, SNI), which the
+system's own TLS 1.0 stack can't.
+
+## Users
+
+Copied into: Plexamp Lite, Podlite, Noticias Lite, Calendar Lite (by hand, under
+`android/org/gingercal/net`), AcasaLite, Tenda Lite and WikipeLite. The apps carry copies, not a dependency.
+
+## What it provides
+
+- `net/Http.java`: HTTP/1.1 on Bouncy Castle TLS 1.2 (renamed `com.minamp.bc`), keep-alive pooling, session
+  resumption, chunked bodies.
+- `net/CertVerifier.java`: host name, validity dates, chain up to a bundled Mozilla root (trust anchors must
+  be CAs); optionally one pinned leaf certificate (SHA-256), with the fingerprint shown to the user. Untrusted
+  errors carry the chain.
+- `net/AssetRoots.java` + `roots/`: Mozilla's roots as `assets/roots/<sha1(subject)>-<n>.der`; loaded roots
+  are kept in memory and a failed read is retried.
+- `net/Threads.java`: threads with a 256 KB stack; network work must run on one.
+- `net/DiagLog.java`: connection log with tokens removed from URLs.
+
+## Must not break
+
+- Must run on Dalvik for API 8: no newer Java or Android APIs.
+- Must not clash with the old Bouncy Castle inside Android (keep the `com.minamp.bc` rename).
+- Never log tokens or passwords.
+- A change here is not done until it has been reinstalled into every app above and each one rebuilt
+  (and released through Tenda).
+
+## Workflow
+
+- `./install.sh <app dir> <java package>` copies `net/` into the app's package and `roots/` into its `assets/`.
+- Bouncy Castle sources come from Plexamp Lite's `tools/setup_toolchain.sh` (`~/android-toolchain/bcsrc`);
+  roots are regenerated with Plexamp Lite's `tools/make_roots.py`.
+- Test: `test/KitTest.java` on a desktop JVM against real FreshRSS, Nextcloud and Audiobookshelf servers.