Add tracking of session renegotiation successs count and test

sslyze/plugins/session_renegotiation_plugin.py

@@ -40,23 +40,26 @@ class SessionRenegotiationScanResult(ScanCommandResult):
     Attributes:
         accepts_client_renegotiation: True if the server honors client-initiated renegotiation attempts.
         supports_secure_renegotiation: True if the server supports secure renegotiation.
+        client_renegotiations_success_count: the number of successful client-initiated renegotiation attempts.
     """
 
     supports_secure_renegotiation: bool
     is_vulnerable_to_client_renegotiation_dos: bool
+    client_renegotiations_success_count: int
 
 
 class SessionRenegotiationScanResultAsJson(BaseModelWithOrmModeAndForbid):
     supports_secure_renegotiation: bool
     is_vulnerable_to_client_renegotiation_dos: bool
+    client_renegotiations_success_count: int
 
 
 class SessionRenegotiationScanAttemptAsJson(ScanCommandAttemptAsJson):
     result: Optional[SessionRenegotiationScanResultAsJson]
 
 
 class _ScanJobResultEnum(Enum):
-    IS_VULNERABLE_TO_CLIENT_RENEG_DOS = 1
+    CLIENT_RENEG_RESULT = 1
     SUPPORTS_SECURE_RENEG = 2
 
 
@@ -87,7 +90,9 @@ def result_to_console_output(cls, result: SessionRenegotiationScanResult) -> Lis
         return result_txt
 
 
-class SessionRenegotiationImplementation(ScanCommandImplementation[SessionRenegotiationScanResult, None]):
+class SessionRenegotiationImplementation(
+    ScanCommandImplementation[SessionRenegotiationScanResult, SessionRenegotiationExtraArgument]
+):
     """Test a server for insecure TLS renegotiation and client-initiated renegotiation."""
 
     cli_connector_cls = _SessionRenegotiationCliConnector
@@ -118,11 +123,13 @@ def result_for_completed_scan_jobs(
             result_enum, value = job.get_result()
             results_dict[result_enum] = value
 
+        is_vulnerable_to_client_renegotiation_dos, client_renegotiations_success_count = results_dict[
+            _ScanJobResultEnum.CLIENT_RENEG_RESULT
+        ]
         return SessionRenegotiationScanResult(
-            is_vulnerable_to_client_renegotiation_dos=results_dict[
-                _ScanJobResultEnum.IS_VULNERABLE_TO_CLIENT_RENEG_DOS
-            ],
+            is_vulnerable_to_client_renegotiation_dos=is_vulnerable_to_client_renegotiation_dos,
             supports_secure_renegotiation=results_dict[_ScanJobResultEnum.SUPPORTS_SECURE_RENEG],
+            client_renegotiations_success_count=client_renegotiations_success_count,
         )
 
 
@@ -163,9 +170,10 @@ def _test_secure_renegotiation(server_info: ServerConnectivityInfo) -> Tuple[_Sc
 
 def _test_client_renegotiation(
     server_info: ServerConnectivityInfo, client_renegotiation_attempts: int
-) -> Tuple[_ScanJobResultEnum, bool]:
+) -> Tuple[_ScanJobResultEnum, Tuple[bool, int]]:
     """Check whether the server honors session renegotiation requests."""
     # Try with TLS 1.2 even if the server supports TLS 1.3 or higher as there is no reneg with TLS 1.3
+    client_renegotiations_success_count = 0
     if server_info.tls_probing_result.highest_tls_version_supported.value >= TlsVersionEnum.TLS_1_3.value:
         tls_version_to_use = TlsVersionEnum.TLS_1_2
         downgraded_from_tls_1_3 = True
@@ -198,6 +206,7 @@ def _test_client_renegotiation(
             # https://github.com/nabla-c0d3/sslyze/issues/473
             for i in range(client_renegotiation_attempts):
                 ssl_connection.ssl_client.do_renegotiate()
+                client_renegotiations_success_count += 1
             accepts_client_renegotiation = True
 
         # Errors caused by a server rejecting the renegotiation
@@ -246,4 +255,4 @@ def _test_client_renegotiation(
     finally:
         ssl_connection.close()
 
-    return _ScanJobResultEnum.IS_VULNERABLE_TO_CLIENT_RENEG_DOS, accepts_client_renegotiation
+    return _ScanJobResultEnum.CLIENT_RENEG_RESULT, (accepts_client_renegotiation, client_renegotiations_success_count)

tests/plugins_tests/test_session_renegotiation_plugin.py

@@ -4,6 +4,7 @@
     SessionRenegotiationImplementation,
     SessionRenegotiationScanResult,
     SessionRenegotiationScanResultAsJson,
+    SessionRenegotiationExtraArgument,
 )
 
 from sslyze.server_setting import (
@@ -40,17 +41,26 @@ def test_renegotiation_good(self) -> None:
     @can_only_run_on_linux_64
     def test_renegotiation_is_vulnerable_to_client_renegotiation_dos(self) -> None:
         # Given a server that is vulnerable to client renegotiation DOS
+        expected_renegotiations_success_count = 3
+
         with LegacyOpenSslServer() as server:
             server_location = ServerNetworkLocation(
                 hostname=server.hostname, ip_address=server.ip_address, port=server.port
             )
+            extra_arg = SessionRenegotiationExtraArgument(
+                client_renegotiation_attempts=expected_renegotiations_success_count
+            )
             server_info = check_connectivity_to_server_and_return_info(server_location)
 
             # When testing for insecure reneg, it succeeds
-            result: SessionRenegotiationScanResult = SessionRenegotiationImplementation.scan_server(server_info)
+            result: SessionRenegotiationScanResult = SessionRenegotiationImplementation.scan_server(
+                server_info,
+                extra_arguments=extra_arg,
+            )
 
         # And the server is reported as vulnerable
         assert result.is_vulnerable_to_client_renegotiation_dos
+        assert result.client_renegotiations_success_count == expected_renegotiations_success_count
 
         # And a CLI output can be generated
         assert SessionRenegotiationImplementation.cli_connector_cls.result_to_console_output(result)