Files
natsnet/dotnet/src/ZB.MOM.NatsNet.Server/NatsServer.Ocsp.cs
2026-02-28 12:34:38 -05:00

634 lines
19 KiB
C#

// Copyright 2012-2026 The NATS Authors
// Licensed under the Apache License, Version 2.0
using System.Net.Security;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using ZB.MOM.NatsNet.Server.Auth.CertificateIdentityProvider;
using ZB.MOM.NatsNet.Server.Auth.Ocsp;
namespace ZB.MOM.NatsNet.Server;
/// <summary>
/// TLS configuration slot used by OCSP wiring to apply wrapped TLS settings.
/// Mirrors Go <c>tlsConfigKind</c> shape used by <c>configureOCSP</c>.
/// </summary>
internal sealed class OcspTlsConfig
{
public required string Kind { get; init; }
public required SslServerAuthenticationOptions TlsConfig { get; init; }
public required TlsConfigOpts? TlsOptions { get; init; }
public required Action<SslServerAuthenticationOptions> Apply { get; init; }
public bool IsLeafSpoke { get; init; }
}
public sealed partial class NatsServer
{
private const string ClientKindName = "client";
private const string RouterKindName = "router";
private const string GatewayKindName = "gateway";
private const string LeafKindName = "leaf";
private const string DefaultOcspStoreDir = "ocsp";
internal OcspMonitor[] GetOcspMonitors()
{
_mu.EnterReadLock();
try
{
return _ocsps is null ? [] : [.. _ocsps];
}
finally
{
_mu.ExitReadLock();
}
}
internal Exception? SetupOCSPStapleStoreDir()
{
var storeDir = GetOpts().StoreDir;
if (string.IsNullOrEmpty(storeDir))
{
return null;
}
var ocspDir = Path.Combine(storeDir, DefaultOcspStoreDir);
try
{
if (!Directory.Exists(ocspDir))
{
Directory.CreateDirectory(ocspDir);
}
else
{
var attributes = File.GetAttributes(ocspDir);
if ((attributes & FileAttributes.Directory) != FileAttributes.Directory)
{
return new InvalidOperationException("OCSP storage directory is not a directory");
}
}
}
catch (Exception ex)
{
return new InvalidOperationException($"could not create OCSP storage directory - {ex.Message}", ex);
}
return null;
}
internal List<OcspTlsConfig> ConfigureOCSP()
{
var opts = GetOpts();
var configs = new List<OcspTlsConfig>();
if (opts.TlsConfig != null)
{
configs.Add(new OcspTlsConfig
{
Kind = ClientKindName,
TlsConfig = opts.TlsConfig,
TlsOptions = opts.TlsConfigOpts,
Apply = tls => opts.TlsConfig = tls,
});
}
if (opts.Websocket.TlsConfig != null)
{
configs.Add(new OcspTlsConfig
{
Kind = ClientKindName,
TlsConfig = opts.Websocket.TlsConfig,
TlsOptions = opts.Websocket.TlsConfigOpts,
Apply = tls => opts.Websocket.TlsConfig = tls,
});
}
if (opts.Mqtt.TlsConfig != null)
{
configs.Add(new OcspTlsConfig
{
Kind = ClientKindName,
TlsConfig = opts.Mqtt.TlsConfig,
TlsOptions = opts.Mqtt.TlsConfigOpts,
Apply = tls => opts.Mqtt.TlsConfig = tls,
});
}
if (opts.Cluster.TlsConfig != null)
{
configs.Add(new OcspTlsConfig
{
Kind = RouterKindName,
TlsConfig = opts.Cluster.TlsConfig,
TlsOptions = opts.Cluster.TlsConfigOpts,
Apply = tls => opts.Cluster.TlsConfig = tls,
});
}
if (opts.LeafNode.TlsConfig != null)
{
configs.Add(new OcspTlsConfig
{
Kind = LeafKindName,
TlsConfig = opts.LeafNode.TlsConfig,
TlsOptions = opts.LeafNode.TlsConfigOpts,
Apply = tls => opts.LeafNode.TlsConfig = tls,
});
}
foreach (var remote in opts.LeafNode.Remotes)
{
if (remote.TlsConfig == null)
{
continue;
}
var capturedRemote = remote;
configs.Add(new OcspTlsConfig
{
Kind = LeafKindName,
TlsConfig = remote.TlsConfig,
TlsOptions = remote.TlsConfigOpts,
IsLeafSpoke = true,
Apply = tls => capturedRemote.TlsConfig = tls,
});
}
if (opts.Gateway.TlsConfig != null)
{
configs.Add(new OcspTlsConfig
{
Kind = GatewayKindName,
TlsConfig = opts.Gateway.TlsConfig,
TlsOptions = opts.Gateway.TlsConfigOpts,
Apply = tls => opts.Gateway.TlsConfig = tls,
});
}
foreach (var gateway in opts.Gateway.Gateways)
{
if (gateway.TlsConfig == null)
{
continue;
}
var capturedGateway = gateway;
configs.Add(new OcspTlsConfig
{
Kind = GatewayKindName,
TlsConfig = gateway.TlsConfig,
TlsOptions = gateway.TlsConfigOpts,
Apply = tls => capturedGateway.TlsConfig = tls,
});
}
return configs;
}
internal (SslServerAuthenticationOptions? tlsConfig, OcspMonitor? monitor, Exception? error) NewOCSPMonitor(
OcspTlsConfig config)
{
var opts = GetOpts();
var ocspConfig = opts.OcspConfig;
var certFile = config.TlsOptions?.CertFile ?? opts.TlsCert;
var caFile = config.TlsOptions?.CaFile ?? opts.TlsCaCert;
if (config.TlsConfig.ServerCertificate is not X509Certificate2 leaf)
{
return (null, null, new InvalidOperationException("no certificate found"));
}
var shutdownOnRevoke = false;
var mustStaple = OcspHandler.HasOCSPStatusRequest(leaf);
if (ocspConfig != null)
{
switch (ocspConfig.Mode)
{
case OcspMode.Never:
if (mustStaple)
{
Warnf("Certificate at '{0}' has MustStaple but OCSP is disabled", certFile);
}
return (config.TlsConfig, null, null);
case OcspMode.Always:
mustStaple = true;
shutdownOnRevoke = true;
break;
case OcspMode.Must when mustStaple:
shutdownOnRevoke = true;
break;
case OcspMode.Auto when !mustStaple:
return (config.TlsConfig, null, null);
}
}
if (!mustStaple)
{
return (config.TlsConfig, null, null);
}
var setupError = SetupOCSPStapleStoreDir();
if (setupError != null)
{
return (null, null, setupError);
}
var chain = new List<byte[]> { leaf.RawData };
if (config.TlsConfig.ServerCertificateContext != null)
{
foreach (var intermediate in config.TlsConfig.ServerCertificateContext.IntermediateCertificates)
{
chain.Add(intermediate.RawData);
}
}
var (issuer, issuerError) = OcspHandler.GetOCSPIssuer(caFile, chain);
if (issuerError != null || issuer == null)
{
return (null, null, issuerError ?? new InvalidOperationException("no issuers found"));
}
var monitor = new OcspMonitor
{
Kind = config.Kind,
Server = this,
CertFile = certFile,
CaFile = caFile,
Leaf = leaf,
Issuer = issuer,
ShutdownOnRevoke = shutdownOnRevoke,
};
var (_, response, statusError) = monitor.GetStatus();
if (statusError != null)
{
return (null, null,
new InvalidOperationException($"bad OCSP status update for certificate at '{certFile}': {statusError.Message}", statusError));
}
if (response != null && response.Status != OcspStatusAssertion.Good && shutdownOnRevoke)
{
return (null, null,
new InvalidOperationException(
$"found existing OCSP status for certificate at '{certFile}': {OcspHandler.OcspStatusString((int)response.Status)}"));
}
return (config.TlsConfig, monitor, null);
}
internal Exception? EnableOCSP()
{
var configs = ConfigureOCSP();
var monitors = new List<OcspMonitor>(configs.Count);
foreach (var config in configs)
{
if (config.Kind != LeafKindName)
{
var (tlsConfig, monitor, error) = NewOCSPMonitor(config);
if (error != null)
{
return error;
}
if (monitor != null && tlsConfig != null)
{
monitors.Add(monitor);
config.Apply(tlsConfig);
}
}
// OCSP peer verification hook is implemented in batch 9 F4.
}
_mu.EnterWriteLock();
try
{
_ocsps = monitors.Count == 0 ? null : [.. monitors];
}
finally
{
_mu.ExitWriteLock();
}
return null;
}
internal void StartOCSPMonitoring()
{
OcspMonitor[]? monitors;
_mu.EnterReadLock();
try
{
monitors = _ocsps;
}
finally
{
_mu.ExitReadLock();
}
if (monitors == null || monitors.Length == 0)
{
return;
}
foreach (var monitor in monitors)
{
Noticef("OCSP Stapling enabled for {0} connections", monitor.Kind);
monitor.Start();
StartGoRoutine(() => monitor.Run(_quitCts.Token).GetAwaiter().GetResult());
}
}
internal Exception? ReloadOCSP()
{
var setupError = SetupOCSPStapleStoreDir();
if (setupError != null)
{
return setupError;
}
var existingMonitors = GetOcspMonitors();
foreach (var monitor in existingMonitors)
{
monitor.Stop();
}
var configs = ConfigureOCSP();
var replacement = new List<OcspMonitor>(configs.Count);
_mu.EnterWriteLock();
try
{
_ocspPeerVerify = false;
}
finally
{
_mu.ExitWriteLock();
}
foreach (var config in configs)
{
if (config.Kind != LeafKindName)
{
var (tlsConfig, monitor, error) = NewOCSPMonitor(config);
if (error != null)
{
return error;
}
if (monitor != null && tlsConfig != null)
{
replacement.Add(monitor);
config.Apply(tlsConfig);
}
}
}
_mu.EnterWriteLock();
try
{
_ocsps = replacement.Count == 0 ? null : [.. replacement];
}
finally
{
_mu.ExitWriteLock();
}
StartOCSPMonitoring();
return null;
}
internal (SslServerAuthenticationOptions? tlsConfig, bool plugged, Exception? error) PlugTLSOCSPPeer(OcspTlsConfig? config)
{
if (config == null || config.TlsConfig == null)
{
return (null, false, new InvalidOperationException(OcspMessages.ErrUnableToPlugTLSEmptyConfig));
}
var kind = config.Kind;
var isSpoke = config.IsLeafSpoke;
var tlsOptions = config.TlsOptions;
if (tlsOptions?.OcspPeerConfig == null || !tlsOptions.OcspPeerConfig.Verify)
{
return (config.TlsConfig, false, null);
}
Debugf(OcspMessages.DbgPlugTLSForKind, config.Kind);
if (kind == ClientKindName || (kind == LeafKindName && !isSpoke))
{
if (!tlsOptions.Verify)
{
return (null, false, new InvalidOperationException(OcspMessages.ErrMTLSRequired));
}
return PlugClientTLSOCSPPeer(config);
}
if (kind == LeafKindName && isSpoke)
{
return PlugServerTLSOCSPPeer(config);
}
return (config.TlsConfig, false, null);
}
internal (SslServerAuthenticationOptions? tlsConfig, bool plugged, Exception? error) PlugClientTLSOCSPPeer(OcspTlsConfig? config)
{
if (config?.TlsConfig == null || config.TlsOptions == null)
{
return (null, false, new InvalidOperationException(OcspMessages.ErrUnableToPlugTLSClient));
}
var tlsConfig = config.TlsConfig;
var tlsOptions = config.TlsOptions;
if (tlsOptions.OcspPeerConfig == null || !tlsOptions.OcspPeerConfig.Verify)
{
return (tlsConfig, false, null);
}
tlsConfig.RemoteCertificateValidationCallback = (_, _, chain, _) =>
{
if (chain?.ChainElements == null || chain.ChainElements.Count == 0)
{
return false;
}
var converted = chain.ChainElements
.Select(e => e.Certificate)
.OfType<X509Certificate2>()
.ToArray();
return TlsClientOCSPValid([converted], tlsOptions.OcspPeerConfig);
};
return (tlsConfig, true, null);
}
internal (SslServerAuthenticationOptions? tlsConfig, bool plugged, Exception? error) PlugServerTLSOCSPPeer(OcspTlsConfig? config)
{
if (config?.TlsConfig == null || config.TlsOptions == null)
{
return (null, false, new InvalidOperationException(OcspMessages.ErrUnableToPlugTLSServer));
}
var tlsConfig = config.TlsConfig;
var tlsOptions = config.TlsOptions;
if (tlsOptions.OcspPeerConfig == null || !tlsOptions.OcspPeerConfig.Verify)
{
return (tlsConfig, false, null);
}
tlsConfig.RemoteCertificateValidationCallback = (_, _, chain, _) =>
{
if (chain?.ChainElements == null || chain.ChainElements.Count == 0)
{
return false;
}
var converted = chain.ChainElements
.Select(e => e.Certificate)
.OfType<X509Certificate2>()
.ToArray();
return TlsServerOCSPValid([converted], tlsOptions.OcspPeerConfig);
};
return (tlsConfig, true, null);
}
internal bool TlsServerOCSPValid(X509Certificate2[][] chains, OcspPeerConfig options)
{
Debugf(OcspMessages.DbgNumServerChains, chains.Length);
return PeerOCSPValid(chains, options);
}
internal bool TlsClientOCSPValid(X509Certificate2[][] chains, OcspPeerConfig options)
{
Debugf(OcspMessages.DbgNumClientChains, chains.Length);
return PeerOCSPValid(chains, options);
}
internal bool PeerOCSPValid(X509Certificate2[][] chains, OcspPeerConfig options)
{
var peer = OcspHandler.PeerFromVerifiedChains(chains);
if (peer == null)
{
Errorf(OcspMessages.ErrPeerEmptyAutoReject);
return false;
}
for (var chainIndex = 0; chainIndex < chains.Length; chainIndex++)
{
var chain = chains[chainIndex];
Debugf(OcspMessages.DbgLinksInChain, chainIndex, chain.Length);
if (chain.Length == 1)
{
Debugf(OcspMessages.DbgSelfSignedValid, chainIndex);
return true;
}
var chainEligible = false;
var eligibleLinks = new List<ChainLink>();
for (var linkPos = 0; linkPos < chain.Length - 1; linkPos++)
{
var cert = chain[linkPos];
var link = new ChainLink { Leaf = cert };
if (OcspUtilities.CertOCSPEligible(link))
{
chainEligible = true;
link.Issuer = chain[linkPos + 1];
eligibleLinks.Add(link);
}
}
if (!chainEligible)
{
Debugf(OcspMessages.DbgValidNonOCSPChain, chainIndex);
return true;
}
Debugf(OcspMessages.DbgChainIsOCSPEligible, chainIndex, eligibleLinks.Count);
var chainValid = true;
foreach (var link in eligibleLinks)
{
var (reason, good) = CertOCSPGood(link, options);
if (good)
{
continue;
}
Debugf(reason);
chainValid = false;
break;
}
if (chainValid)
{
Debugf(OcspMessages.DbgChainIsOCSPValid, chainIndex);
return true;
}
}
Debugf(OcspMessages.DbgNoOCSPValidChains);
return false;
}
internal (string reason, bool good) CertOCSPGood(ChainLink? link, OcspPeerConfig options)
{
if (link?.Leaf == null || link.Issuer == null || link.OcspWebEndpoints == null || link.OcspWebEndpoints.Count == 0)
{
return ("Empty chainlink found", false);
}
var log = new OcspLog
{
Debugf = (fmt, args) => Debugf(fmt, args),
Noticef = (fmt, args) => Noticef(fmt, args),
Warnf = (fmt, args) => Warnf(fmt, args),
Errorf = (fmt, args) => Errorf(fmt, args),
};
var fingerprint = Convert.ToHexString(SHA256.HashData(link.Leaf.RawData)).ToLowerInvariant();
var cached = _ocsprc?.Get(fingerprint);
if (cached is { Length: > 0 })
{
var (parsed, parseError) = OcspHandler.ParseOcspResponse(cached);
if (parseError == null && parsed != null && OcspUtilities.OCSPResponseCurrent(parsed, options, log))
{
if (parsed.Status == OcspStatusAssertion.Revoked ||
(parsed.Status == OcspStatusAssertion.Unknown && !options.UnknownIsGood))
{
if (options.WarnOnly)
{
Warnf("allowing OCSP peer due warn_only for [{0}]", link.Leaf.Subject);
return (string.Empty, true);
}
return ($"OCSP response invalid status: {OcspStatusAssertionExtensions.GetStatusAssertionStr((int)parsed.Status)}", false);
}
Debugf(OcspMessages.DbgOCSPValidPeerLink, link.Leaf.Subject);
return (string.Empty, true);
}
}
if (options.AllowWhenCAUnreachable || options.WarnOnly)
{
if (options.WarnOnly)
{
Warnf("allowing OCSP peer due warn_only for [{0}]", link.Leaf.Subject);
}
if (options.AllowWhenCAUnreachable)
{
Warnf("allowing OCSP peer due unreachable CA for [{0}]", link.Leaf.Subject);
}
return (string.Empty, true);
}
return ("failed to fetch OCSP response", false);
}
}