chore: better error reporting when connecting to tls with plain socket (#2740)

* chore: better error reporting when connecting to tls with plain socket

---------

Signed-off-by: Roman Gershman <roman@dragonflydb.io>

helio

@@ -1 +1 @@
-Subproject commit 91c4f48d025bccd6fc3ff14e471accf1c7801f38
+Subproject commit 8985263c3acca038752e8f9fdd8e9f61d2ec2b6f

src/facade/dragonfly_connection.cc

@@ -6,12 +6,12 @@
 
 #include <absl/container/flat_hash_map.h>
 #include <absl/strings/match.h>
+#include <absl/strings/str_cat.h>
 #include <mimalloc.h>
 
 #include <numeric>
 #include <variant>
 
-#include "absl/strings/str_cat.h"
 #include "base/flags.h"
 #include "base/io_buf.h"
 #include "base/logging.h"
@@ -613,10 +613,25 @@ void Connection::HandleRequests() {
     if (!(IsPrivileged() && no_tls_on_admin_port)) {
       // Must be done atomically before the premption point in Accept so that at any
       // point in time, the socket_ is defined.
+      uint8_t buf[2];
+      auto read_sz = socket_->Read(io::MutableBytes(buf));
+      if (!read_sz || *read_sz < sizeof(buf)) {
+        VLOG(1) << "Error reading from peer " << remote_ep << " " << read_sz.error().message();
+        return;
+      }
+      if (buf[0] != 0x16 || buf[1] != 0x03) {
+        VLOG(1) << "Bad TLS header "
+                << absl::StrCat(absl::Hex(buf[0], absl::kZeroPad2),
+                                absl::Hex(buf[1], absl::kZeroPad2));
+        peer->Write(
+            io::Buffer("-ERR Bad TLS header, double check "
+                       "if you enabled TLS for your client.\r\n"));
+      }
+
       {
         FiberAtomicGuard fg;
         unique_ptr<tls::TlsSocket> tls_sock = make_unique<tls::TlsSocket>(std::move(socket_));
-        tls_sock->InitSSL(ssl_ctx_);
+        tls_sock->InitSSL(ssl_ctx_, buf);
         SetSocket(tls_sock.release());
       }
       FiberSocketBase::AcceptResult aresult = socket_->Accept();

tests/dragonfly/connection_test.py

@@ -4,12 +4,12 @@ import pytest
 import asyncio
 import time
 from redis import asyncio as aioredis
-from redis.exceptions import ConnectionError as redis_conn_error
+from redis.exceptions import ConnectionError as redis_conn_error, ResponseError
 import async_timeout
 from dataclasses import dataclass
 
 from . import dfly_args
-from .instance import DflyInstance
+from .instance import DflyInstance, DflyInstanceFactory
 
 BASE_PORT = 1111
 
@@ -564,7 +564,7 @@ async def test_large_cmd(async_client: aioredis.Redis):
 
 @pytest.mark.asyncio
 async def test_reject_non_tls_connections_on_tls(with_tls_server_args, df_local_factory):
-    server = df_local_factory.create(
+    server: DflyInstance = df_local_factory.create(
         no_tls_on_admin_port="true",
         admin_port=1111,
         port=1211,
@@ -573,13 +573,12 @@ async def test_reject_non_tls_connections_on_tls(with_tls_server_args, df_local_
     )
     server.start()
 
-    client = aioredis.Redis(port=server.port, password="XXX")
-    try:
-        await client.execute_command("DBSIZE")
-    except redis_conn_error:
-        pass
+    client = server.client(password="XXX")
+    with pytest.raises((ResponseError)):
+        await client.dbsize()
+    await client.close()
 
-    client = aioredis.Redis(port=server.admin_port, password="XXX")
+    client = server.admin_client(password="XXX")
     assert await client.dbsize() == 0
     await client.close()
 
@@ -605,27 +604,19 @@ async def test_tls_full_auth(with_ca_tls_server_args, with_ca_tls_client_args, d
 
 
 @pytest.mark.asyncio
-async def test_tls_reject(with_ca_tls_server_args, with_tls_client_args, df_local_factory):
-    server = df_local_factory.create(port=BASE_PORT, **with_ca_tls_server_args)
+async def test_tls_reject(
+    with_ca_tls_server_args, with_tls_client_args, df_local_factory: DflyInstanceFactory
+):
+    server: DflyInstance = df_local_factory.create(port=BASE_PORT, **with_ca_tls_server_args)
     server.start()
 
-    client = aioredis.Redis(port=server.port, **with_tls_client_args, ssl_cert_reqs=None)
-    try:
+    client = server.client(**with_tls_client_args, ssl_cert_reqs=None)
+    await client.ping()
+    await client.close()
+
+    client = server.client(**with_tls_client_args)
+    with pytest.raises(redis_conn_error):
         await client.ping()
-    except redis_conn_error:
-        pass
-
-    client = aioredis.Redis(port=server.port, **with_tls_client_args)
-    try:
-        assert await client.dbsize() != 0
-    except redis_conn_error:
-        pass
-
-    client = aioredis.Redis(port=server.port, ssl_cert_reqs=None)
-    try:
-        assert await client.dbsize() != 0
-    except redis_conn_error:
-        pass
     await client.close()
 
 

tests/dragonfly/tls_conf_test.py

@@ -141,7 +141,7 @@ async def test_config_enable_tls(
             await client.ping()
 
         # Connecting without TLS should fail.
-        with pytest.raises(redis.exceptions.ConnectionError):
+        with pytest.raises(redis.exceptions.ResponseError):
             async with server.client() as client_unauth:
                 await client_unauth.ping()