feat: I2P integration (process-based) + updated icons + Qt UI for I2P address display

src/i2p.h

@@ -0,0 +1,95 @@
+// Copyright (c) 2024 Triangles developers
+// I2P (SAM v3) transport support
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+//
+// This module gives Triangles real I2P connectivity that mirrors the existing
+// embedded-Tor design: instead of a SOCKS proxy it talks the SAM v3 protocol
+// to a locally running I2P router (i2pd or Java I2P) and obtains a persistent
+// I2P destination whose ".b32.i2p" address is shown alongside the .onion
+// address.  The wallet:
+//   * creates / loads a persistent destination (i2p_private_key in datadir),
+//   * runs a STREAM session so peers can dial us,
+//   * accepts inbound I2P streams and feeds them to the net layer,
+//   * dials outbound ".b32.i2p" peers through the same session.
+//
+// A running I2P router with its SAM bridge enabled (default 127.0.0.1:7656) is
+// required; nothing is bundled.  Enable with -i2p and optionally -i2psam=host:port.
+
+#ifndef TRIANGLES_I2P_H
+#define TRIANGLES_I2P_H
+
+#include <atomic>
+#include <mutex>
+#include <string>
+#include <thread>
+
+#include "compat.h"   // SOCKET / INVALID_SOCKET
+
+// Default SAM bridge endpoint exposed by i2pd / Java I2P.
+#define I2P_DEFAULT_SAM_HOST "127.0.0.1"
+#define I2P_DEFAULT_SAM_PORT 7656
+
+// Manages a single persistent I2P STREAM session over SAM v3.
+class CI2PSession
+{
+public:
+    static CI2PSession* GetInstance();
+
+    // Bring the session up: connect to the SAM bridge, load/generate the
+    // persistent destination and start accepting inbound streams.
+    // Returns false (and logs) if no router/SAM bridge is reachable.
+    bool Start();
+
+    // Tear the session down and stop the accept loop.
+    void Stop();
+
+    bool IsEnabled() const { return fEnabled.load(); }
+    bool IsActive() const { return fActive.load(); }
+
+    // Our own ".b32.i2p" address (empty until the session is up).
+    std::string GetB32Address();
+
+    // Dial a remote ".b32.i2p" (or full base64 destination) through the
+    // session.  On success hSocketRet is a connected, blocking data socket the
+    // caller can hand to a CNode.  The caller takes ownership of the socket.
+    bool Connect(const std::string& strDest, SOCKET& hSocketRet);
+
+private:
+    CI2PSession();
+    ~CI2PSession();
+
+    // --- low level SAM helpers ---
+    bool SamConnect(SOCKET& hSocketRet);                 // raw TCP to the bridge
+    bool SamHandshake(SOCKET hSocket);                   // HELLO VERSION
+    bool SamSendLine(SOCKET hSocket, const std::string& strLine);
+    bool SamRecvLine(SOCKET hSocket, std::string& strLineRet);
+    static std::string SamGetValue(const std::string& strReply, const std::string& strKey);
+
+    bool LoadOrCreateDestination(std::string& strPrivKeyRet);
+    bool CreateSession();                                 // SESSION CREATE
+    bool ResolveMyB32();                                  // NAMING LOOKUP ME
+    void AcceptLoop();                                    // inbound STREAM ACCEPT
+
+    // Compute the ".b32.i2p" address from a base64 (I2P alphabet) destination.
+    static std::string DestToB32(const std::string& strB64Dest);
+
+    std::string samHost;
+    int samPort;
+    std::string sessionId;
+    std::string privateKey;   // persistent destination private key (base64)
+    std::string b32Address;   // our own .b32.i2p
+    SOCKET hSession;          // long-lived control socket owning the session
+
+    std::atomic<bool> fEnabled;
+    std::atomic<bool> fActive;
+    std::atomic<bool> fShutdown;
+    std::thread acceptThread;
+    std::mutex cs;
+};
+
+// Convenience: start/stop from init.cpp.
+bool StartI2P();
+void StopI2P();
+
+#endif // TRIANGLES_I2P_H