Merge bitcoin/bitcoin#22050: p2p: remove tor v2 support

5d82a57db4f67506a4e80d186ba76f3a8665e147 contrib: remove torv2 seed nodes (Jon Atack)
5f7e086dac78c9070f8292a1757d7e77e110f772 contrib: update generate-seeds.py to ignore torv2 addresses (Jon Atack)
8be56f0f8ecc54744d572e5678a3089665587b98 p2p, refactor: extract OnionToString() from CNetAddr::ToStringIp() (Jon Atack)
5f9d3c09b4c9cd026cdc7c3a81f91632280917b7 p2p: remove torv2 from CNetAddr::ToStringIP() (Jon Atack)
3d390421440f1cae9a9f2b089561c183ecd1b073 p2p: remove torv2 in SetIP() and ADDR_TORV2_SIZE constant (Jon Atack)
cff5ec477a388ae9aa9fd9ef6a7dad1f678e7d23 p2p: remove pre-addrv2 onions from SerializeV1Array() (Jon Atack)
4192a74413907717d6173e393724b931f2225dd9 p2p: ignore torv2-in-ipv6 addresses in SetLegacyIPv6() (Jon Atack)
1d631e956fffbbc7891ed40be4fd39aeff036c52 p2p: remove BIP155Network::TORV2 from GetBIP155Network() (Jon Atack)
7d1769bc450a98c093a066d6daed84337040dbfb p2p: remove torv2 from SetNetFromBIP155Network() (Jon Atack)
eba9a94b9f56be2fda623e77f19b960425ea1eb5 fuzz: rename CNetAddr/CService deserialize targets (Jon Atack)
c56a1c9b182815018b8bd3d8e6b8c2cb27859607 p2p: drop onions from IsAddrV1Compatible(), no longer relay torv2 (Jon Atack)
f8e94002fcfdc7890d38c23488b1f3a662e97bc4 p2p: remove torv2/ADDR_TORV2_SIZE from SetTor() (Jon Atack)
0f1c58ae87d6a3fe81816500e7b8275420d151d0 test: update feature_proxy to torv3 (Jon Atack)

Pull request description:

  ![image](https://user-images.githubusercontent.com/2415484/120018909-4d425a00-bfd7-11eb-83c9-95a3dac97926.jpeg)

  This patch removes support in Bitcoin Core for Tor v2 onions, which are already removed from the release of Tor 0.4.6.

  - no longer serialize/deserialize and relay Tor v2 addresses
  - ignore incoming Tor v2 addresses
  - remove Tor v2 addresses from the addrman and peers.dat on node launch
  - update generate-seeds.py to ignore Tor v2 addresses
  - remove Tor v2 hard-coded seeds

  Tested with tor-0.4.6.1-alpha (no v2 support) and 0.4.5.7 (v2 support). With the latest Tor (no v2 support), this removes all the warnings like those reported with current master in https://github.com/bitcoin/bitcoin/issues/21351

  ```
  <bitcoind debug log>
  Socks5() connect to […].onion:8333 failed: general failure

  <tor log>
  Invalid hostname [scrubbed]; rejecting
  ```

  and the addrman no longer has Tor v2 addresses on launching bitcoind.
  ```rake
  $ ./src/bitcoin-cli -addrinfo
  {
    "addresses_known": {
      "ipv4": 44483,
      "ipv6": 8467,
      "torv2": 0,
      "torv3": 2296,
      "i2p": 6,
      "total": 55252
    }
  }
  ```
  After recompiling back to current master and restarting with either of the two Tor versions (0.4.5.7 or 0.4.6.1), -addrinfo initially returns 0 Tor v2 addresses and then begins finding them again.

  Ran nodes on this patch over the past week on mainnet/testnet/signet/regtest after building with DEBUG_ADDRMAN.

  Verified that this patch bootstraps an onlynet=onion node from the Tor v3 hardcoded fixed seeds on mainnet and testnet and connects to blocks and v3 onion peers: `rm ~/.bitcoin/testnet3/peers.dat ; ./src/bitcoind -testnet -dnsseed=0 -onlynet=onion`

  ![Screenshot from 2021-05-28 00-26-17](https://user-images.githubusercontent.com/2415484/119905021-ea02ea00-bf3a-11eb-875f-27ef57640c49.png)

  Tested using `addnode`, `getaddednodeinfo`,`addpeeraddress`, `disconnectnode` and `-addrinfo` that a currently valid, connectable Tor v2 peer can no longer be added:

  ![Screenshot from 2021-05-30 11-32-05](https://user-images.githubusercontent.com/2415484/120099282-29435d80-c12a-11eb-81b6-5084244d7d2a.png)

  Thanks to Vasil Dimov, Carl Dong, and Wladimir J. van der Laan for their work on BIP155 and Tor v3 that got us here.

ACKs for top commit:
  laanwj:
    Code review ACK 5d82a57db4f67506a4e80d186ba76f3a8665e147

Tree-SHA512: 590ff3d2f6ef682608596facb4b01f44fef69716d2ab3552ae1655aa225f4bf104f9ee08d6769abb9982a8031de93340df553279ce1f5023771f9f2b651178bb

3 files changed, 22 insertions, 59 deletions

diff --git a/src/test/fuzz/deserialize.cpp b/src/test/fuzz/deserialize.cpp
index 1290c78712..700e368319 100644
--- a/src/test/fuzz/deserialize.cpp
+++ b/src/test/fuzz/deserialize.cpp
@@ -143,7 +143,7 @@ FUZZ_TARGET_DESERIALIZE(script_deserialize, {
         CScript script;
         DeserializeFromFuzzingInput(buffer, script);
 })
-FUZZ_TARGET_DESERIALIZE(sub_net_deserialize, {
+FUZZ_TARGET_DESERIALIZE(subnet_deserialize, {
         CSubNet sub_net_1;
         DeserializeFromFuzzingInput(buffer, sub_net_1, INIT_PROTO_VERSION);
         AssertEqualAfterSerializeDeserialize(sub_net_1, INIT_PROTO_VERSION);
@@ -223,7 +223,7 @@ FUZZ_TARGET_DESERIALIZE(coins_deserialize, {
         Coin coin;
         DeserializeFromFuzzingInput(buffer, coin);
 })
-FUZZ_TARGET_DESERIALIZE(netaddr_deserialize, {
+FUZZ_TARGET_DESERIALIZE(net_address_deserialize, {
         CNetAddr na;
         DeserializeFromFuzzingInput(buffer, na);
         if (na.IsAddrV1Compatible()) {
@@ -231,7 +231,7 @@ FUZZ_TARGET_DESERIALIZE(netaddr_deserialize, {
         }
         AssertEqualAfterSerializeDeserialize(na, INIT_PROTO_VERSION | ADDRV2_FORMAT);
 })
-FUZZ_TARGET_DESERIALIZE(service_deserialize, {
+FUZZ_TARGET_DESERIALIZE(net_service_deserialize, {
         CService s;
         DeserializeFromFuzzingInput(buffer, s);
         if (s.IsAddrV1Compatible()) {
diff --git a/src/test/net_tests.cpp b/src/test/net_tests.cpp
index 7a122bd8b0..46f88c1282 100644
--- a/src/test/net_tests.cpp
+++ b/src/test/net_tests.cpp
@@ -318,15 +318,8 @@ BOOST_AUTO_TEST_CASE(cnetaddr_basic)
     BOOST_CHECK(!addr.IsBindAny());
     BOOST_CHECK_EQUAL(addr.ToString(), link_local);
 
-    // TORv2
-    BOOST_REQUIRE(addr.SetSpecial("6hzph5hv6337r6p2.onion"));
-    BOOST_REQUIRE(addr.IsValid());
-    BOOST_REQUIRE(addr.IsTor());
-
-    BOOST_CHECK(!addr.IsI2P());
-    BOOST_CHECK(!addr.IsBindAny());
-    BOOST_CHECK(addr.IsAddrV1Compatible());
-    BOOST_CHECK_EQUAL(addr.ToString(), "6hzph5hv6337r6p2.onion");
+    // TORv2, no longer supported
+    BOOST_CHECK(!addr.SetSpecial("6hzph5hv6337r6p2.onion"));
 
     // TORv3
     const char* torv3_addr = "pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion";
@@ -470,10 +463,8 @@ BOOST_AUTO_TEST_CASE(cnetaddr_serialize_v1)
     BOOST_CHECK_EQUAL(HexStr(s), "1a1b2a2b3a3b4a4b5a5b6a6b7a7b8a8b");
     s.clear();
 
-    BOOST_REQUIRE(addr.SetSpecial("6hzph5hv6337r6p2.onion"));
-    s << addr;
-    BOOST_CHECK_EQUAL(HexStr(s), "fd87d87eeb43f1f2f3f4f5f6f7f8f9fa");
-    s.clear();
+    // TORv2, no longer supported
+    BOOST_CHECK(!addr.SetSpecial("6hzph5hv6337r6p2.onion"));
 
     BOOST_REQUIRE(addr.SetSpecial("pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion"));
     s << addr;
@@ -508,10 +499,8 @@ BOOST_AUTO_TEST_CASE(cnetaddr_serialize_v2)
     BOOST_CHECK_EQUAL(HexStr(s), "02101a1b2a2b3a3b4a4b5a5b6a6b7a7b8a8b");
     s.clear();
 
-    BOOST_REQUIRE(addr.SetSpecial("6hzph5hv6337r6p2.onion"));
-    s << addr;
-    BOOST_CHECK_EQUAL(HexStr(s), "030af1f2f3f4f5f6f7f8f9fa");
-    s.clear();
+    // TORv2, no longer supported
+    BOOST_CHECK(!addr.SetSpecial("6hzph5hv6337r6p2.onion"));
 
     BOOST_REQUIRE(addr.SetSpecial("kpgvmscirrdqpekbqjsvw5teanhatztpp2gl6eee4zkowvwfxwenqaid.onion"));
     s << addr;
@@ -617,26 +606,14 @@ BOOST_AUTO_TEST_CASE(cnetaddr_unserialize_v2)
     BOOST_CHECK(!addr.IsValid());
     BOOST_REQUIRE(s.empty());
 
-    // Valid TORv2.
+    // TORv2, no longer supported.
     s << MakeSpan(ParseHex("03"                      // network type (TORv2)
                            "0a"                      // address length
                            "f1f2f3f4f5f6f7f8f9fa")); // address
     s >> addr;
-    BOOST_CHECK(addr.IsValid());
-    BOOST_CHECK(addr.IsTor());
-    BOOST_CHECK(addr.IsAddrV1Compatible());
-    BOOST_CHECK_EQUAL(addr.ToString(), "6hzph5hv6337r6p2.onion");
+    BOOST_CHECK(!addr.IsValid());
     BOOST_REQUIRE(s.empty());
 
-    // Invalid TORv2, with bogus length.
-    s << MakeSpan(ParseHex("03"    // network type (TORv2)
-                           "07"    // address length
-                           "00")); // address
-    BOOST_CHECK_EXCEPTION(s >> addr, std::ios_base::failure,
-                          HasReason("BIP155 TORv2 address with length 7 (should be 10)"));
-    BOOST_REQUIRE(!s.empty()); // The stream is not consumed on invalid input.
-    s.clear();
-
     // Valid TORv3.
     s << MakeSpan(ParseHex("04"                               // network type (TORv3)
                            "20"                               // address length
diff --git a/src/test/netbase_tests.cpp b/src/test/netbase_tests.cpp
index 3c47cf83e2..687d2f6747 100644
--- a/src/test/netbase_tests.cpp
+++ b/src/test/netbase_tests.cpp
@@ -44,13 +44,12 @@ static CNetAddr CreateInternal(const std::string& host)
 
 BOOST_AUTO_TEST_CASE(netbase_networks)
 {
-    BOOST_CHECK(ResolveIP("127.0.0.1").GetNetwork()                              == NET_UNROUTABLE);
-    BOOST_CHECK(ResolveIP("::1").GetNetwork()                                    == NET_UNROUTABLE);
-    BOOST_CHECK(ResolveIP("8.8.8.8").GetNetwork()                                == NET_IPV4);
-    BOOST_CHECK(ResolveIP("2001::8888").GetNetwork()                             == NET_IPV6);
-    BOOST_CHECK(ResolveIP("FD87:D87E:EB43:edb1:8e4:3588:e546:35ca").GetNetwork() == NET_ONION);
-    BOOST_CHECK(CreateInternal("foo.com").GetNetwork()                           == NET_INTERNAL);
-
+    BOOST_CHECK(ResolveIP("127.0.0.1").GetNetwork() == NET_UNROUTABLE);
+    BOOST_CHECK(ResolveIP("::1").GetNetwork() == NET_UNROUTABLE);
+    BOOST_CHECK(ResolveIP("8.8.8.8").GetNetwork() == NET_IPV4);
+    BOOST_CHECK(ResolveIP("2001::8888").GetNetwork() == NET_IPV6);
+    BOOST_CHECK(ResolveIP("pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion").GetNetwork() == NET_ONION);
+    BOOST_CHECK(CreateInternal("foo.com").GetNetwork() == NET_INTERNAL);
 }
 
 BOOST_AUTO_TEST_CASE(netbase_properties)
@@ -73,7 +72,7 @@ BOOST_AUTO_TEST_CASE(netbase_properties)
     BOOST_CHECK(ResolveIP("2001:20::").IsRFC7343());
     BOOST_CHECK(ResolveIP("FE80::").IsRFC4862());
     BOOST_CHECK(ResolveIP("64:FF9B::").IsRFC6052());
-    BOOST_CHECK(ResolveIP("FD87:D87E:EB43:edb1:8e4:3588:e546:35ca").IsTor());
+    BOOST_CHECK(ResolveIP("pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion").IsTor());
     BOOST_CHECK(ResolveIP("127.0.0.1").IsLocal());
     BOOST_CHECK(ResolveIP("::1").IsLocal());
     BOOST_CHECK(ResolveIP("8.8.8.8").IsRoutable());
@@ -133,18 +132,6 @@ BOOST_AUTO_TEST_CASE(netbase_lookupnumeric)
     BOOST_CHECK(TestParse("[fd6c:88c0:8724:1:2:3:4:5]", "[fd6c:88c0:8724:1:2:3:4:5]:65535"));
 }
 
-BOOST_AUTO_TEST_CASE(onioncat_test)
-{
-    // values from https://web.archive.org/web/20121122003543/http://www.cypherpunk.at/onioncat/wiki/OnionCat
-    CNetAddr addr1(ResolveIP("5wyqrzbvrdsumnok.onion"));
-    CNetAddr addr2(ResolveIP("FD87:D87E:EB43:edb1:8e4:3588:e546:35ca"));
-    BOOST_CHECK(addr1 == addr2);
-    BOOST_CHECK(addr1.IsTor());
-    BOOST_CHECK(addr1.ToStringIP() == "5wyqrzbvrdsumnok.onion");
-    BOOST_CHECK(addr1.IsRoutable());
-
-}
-
 BOOST_AUTO_TEST_CASE(embedded_test)
 {
     CNetAddr addr1(ResolveIP("1.2.3.4"));
@@ -338,7 +325,6 @@ BOOST_AUTO_TEST_CASE(netbase_getgroup)
     BOOST_CHECK(ResolveIP("64:FF9B::102:304").GetGroup(asmap) == std::vector<unsigned char>({(unsigned char)NET_IPV4, 1, 2})); // RFC6052
     BOOST_CHECK(ResolveIP("2002:102:304:9999:9999:9999:9999:9999").GetGroup(asmap) == std::vector<unsigned char>({(unsigned char)NET_IPV4, 1, 2})); // RFC3964
     BOOST_CHECK(ResolveIP("2001:0:9999:9999:9999:9999:FEFD:FCFB").GetGroup(asmap) == std::vector<unsigned char>({(unsigned char)NET_IPV4, 1, 2})); // RFC4380
-    BOOST_CHECK(ResolveIP("FD87:D87E:EB43:edb1:8e4:3588:e546:35ca").GetGroup(asmap) == std::vector<unsigned char>({(unsigned char)NET_ONION, 239})); // Tor
     BOOST_CHECK(ResolveIP("2001:470:abcd:9999:9999:9999:9999:9999").GetGroup(asmap) == std::vector<unsigned char>({(unsigned char)NET_IPV6, 32, 1, 4, 112, 175})); //he.net
     BOOST_CHECK(ResolveIP("2001:2001:9999:9999:9999:9999:9999:9999").GetGroup(asmap) == std::vector<unsigned char>({(unsigned char)NET_IPV6, 32, 1, 32, 1})); //IPv6
 
@@ -481,10 +467,10 @@ BOOST_AUTO_TEST_CASE(netbase_dont_resolve_strings_with_embedded_nul_characters)
     BOOST_CHECK(!LookupSubNet("1.2.3.0/24\0"s, ret));
     BOOST_CHECK(!LookupSubNet("1.2.3.0/24\0example.com"s, ret));
     BOOST_CHECK(!LookupSubNet("1.2.3.0/24\0example.com\0"s, ret));
-    BOOST_CHECK(LookupSubNet("5wyqrzbvrdsumnok.onion"s, ret));
-    BOOST_CHECK(!LookupSubNet("5wyqrzbvrdsumnok.onion\0"s, ret));
-    BOOST_CHECK(!LookupSubNet("5wyqrzbvrdsumnok.onion\0example.com"s, ret));
-    BOOST_CHECK(!LookupSubNet("5wyqrzbvrdsumnok.onion\0example.com\0"s, ret));
+    BOOST_CHECK(LookupSubNet("pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion"s, ret));
+    BOOST_CHECK(!LookupSubNet("pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion\0"s, ret));
+    BOOST_CHECK(!LookupSubNet("pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion\0example.com"s, ret));
+    BOOST_CHECK(!LookupSubNet("pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion\0example.com\0"s, ret));
 }
 
 // Since CNetAddr (un)ser is tested separately in net_tests.cpp here we only