Fix bugs in I2P implementation

Bug fixes:
1. i2p_tests.cpp: Fix comment/assertion mismatch in i2p_service test
   - Updated comments to clarify that CService preserves ports but SAM rejects non-zero ports

2. net.cpp: Fix I2P connections when pszDest is provided
   - Parse .b32.i2p addresses from pszDest before checking IsI2P()
   - Update addrConnect with parsed I2P address for correct CNode creation
   - This ensures -addnode=xxx.b32.i2p works correctly

3. i2p.cpp: Validate corrupted private keys, not just empty ones
   - Call MyDestination() after loading private key to detect corruption
   - Regenerate key if validation fails (truncated/corrupted files)

Co-authored-by: reuben <[email protected]>

Author: cursoragent

src/i2p.cpp

@@ -518,6 +518,16 @@ void Session::CreateIfNotCreatedAlready()
                     if (m_private_key.empty()) {
                         LogPrintf("I2P: Private key file %s is empty, regenerating\n", m_private_key_file.string());
                         GenerateAndSavePrivateKey(sock);
+                    } else {
+                        // Validate the private key by attempting to derive the destination
+                        // This will detect truncated or corrupted key files
+                        try {
+                            MyDestination();
+                        } catch (const std::runtime_error& e) {
+                            LogPrintf("I2P: Private key file %s is corrupted (%s), regenerating\n", 
+                                      m_private_key_file.string(), e.what());
+                            GenerateAndSavePrivateKey(sock);
+                        }
                     }
                 } else {
                     GenerateAndSavePrivateKey(sock);

src/net.cpp

@@ -31,6 +31,8 @@
 #include "evo/mnauth.h"
 #include "i2p.h"
 
+#include <algorithm>
+
 #ifdef WIN32
 #include <string.h>
 #else
@@ -400,8 +402,36 @@ CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCo
     bool proxyConnectionFailed = false;
     bool connected = false;
 
+    // Check if this is an I2P connection - either via addrConnect or pszDest
+    bool isI2P = addrConnect.IsI2P();
+    CService i2pDest;
+    
+    // If pszDest is provided, check if it's an I2P address (.b32.i2p suffix)
+    if (!isI2P && pszDest) {
+        std::string dest(pszDest);
+        // Check for I2P address suffix (case-insensitive)
+        if (dest.size() > 8) {
+            std::string suffix = dest.substr(dest.size() - 8);
+            std::transform(suffix.begin(), suffix.end(), suffix.begin(), ::tolower);
+            if (suffix == ".b32.i2p") {
+                CNetAddr i2pAddr;
+                if (i2pAddr.SetSpecial(dest)) {
+                    i2pDest = CService(i2pAddr, i2p::I2P_SAM31_PORT);
+                    isI2P = true;
+                    LogPrint("i2p", "I2P: Parsed destination %s from pszDest\n", i2pDest.ToString());
+                }
+            }
+        }
+    }
+
     // Handle I2P connections via SAM session
-    if (addrConnect.IsI2P()) {
+    if (isI2P) {
+        // Use i2pDest if we parsed from pszDest, otherwise use addrConnect
+        if (i2pDest.IsValid()) {
+            // Update addrConnect so it's used correctly for CNode creation and address manager
+            addrConnect = CAddress(i2pDest, addrConnect.nServices);
+        }
+        
         if (m_i2p_sam_session) {
             i2p::Connection conn;
             if (m_i2p_sam_session->Connect(addrConnect, conn, proxyConnectionFailed)) {

src/test/i2p_tests.cpp

@@ -113,12 +113,13 @@ BOOST_AUTO_TEST_CASE(i2p_service)
     const std::string valid_i2p = "ukeu3k5oycgaauneqgtnvselmt4yemvoilkln7jpvamvfx7dnkdq.b32.i2p";
     BOOST_CHECK(addr.SetSpecial(valid_i2p));
 
-    // I2P uses port 0 (SAM 3.1 doesn't use ports)
+    // I2P SAM 3.1 uses port 0 as the standard port
     CService service(addr, 0);
     BOOST_CHECK(service.IsI2P());
     BOOST_CHECK_EQUAL(service.GetPort(), 0);
 
-    // The port in I2P is always 0, so testing with non-zero port
+    // CService preserves whatever port is supplied, even for I2P addresses.
+    // However, the I2P SAM session will reject non-zero ports when connecting.
     CService service2(addr, 8333);
     BOOST_CHECK_EQUAL(service2.GetPort(), 8333);
 }