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[BED-6140] Add cache invalidation #158

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[BED-6140] Add cache invalidation #158

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e69f4e2
fix: Add cache invalidation
definitelynotagoblin Jul 2, 2025
fe40ec8
chore: Formatting
definitelynotagoblin Jul 2, 2025
3f147fe
fix: Create new cache with version when invalidating
definitelynotagoblin Jul 2, 2025
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59 changes: 45 additions & 14 deletions src/SharpLinks.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,7 @@
using System.DirectoryServices.ActiveDirectory;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Security.Principal;
using System.Threading.Tasks;
using Microsoft.Extensions.Logging;
Expand All @@ -29,8 +30,7 @@
using SharpHoundCommonLib.Processors;
using Timer = System.Timers.Timer;

namespace Sharphound
{
namespace Sharphound {
internal class SharpLinks : Links<IContext> {
/// <summary>
/// Define methods that SharpHound executes as part of operation pipeline.
Expand Down Expand Up @@ -62,7 +62,8 @@ public IContext Initialize(IContext context, LdapConfig options) {
if (!context.LDAPUtils.GetDomain(out var d)) {
context.Logger.LogCritical("unable to get current domain");
context.Flags.IsFaulted = true;
} else {
}
else {
context.DomainName = d.Name;
context.Logger.LogInformation("Resolved current domain to {Domain}", d.Name);
}
Expand Down Expand Up @@ -90,7 +91,8 @@ public IContext Initialize(IContext context, LdapConfig options) {
}

File.Delete(filename);
} catch (Exception e) {
}
catch (Exception e) {
context.Logger.LogCritical(e, "unable to write to target directory");
context.Flags.IsFaulted = true;
}
Expand Down Expand Up @@ -137,26 +139,53 @@ public IContext InitCommonLib(IContext context) {
context.Logger.LogTrace("Getting cache path");
var path = context.GetCachePath();
context.Logger.LogTrace("Cache Path: {Path}", path);

var version = Assembly.GetExecutingAssembly().GetName().Version;
Cache cache;
if (!File.Exists(path)) {
context.Logger.LogTrace("Cache file does not exist");
cache = null;
} else
cache = Cache.CreateNewCache(version);
}
else if (context.Flags.InvalidateCache) {
context.Logger.LogTrace($"Skipping cache load per option {nameof(Options.RebuildCache)}");
cache = Cache.CreateNewCache(version);
}
else {
try {
context.Logger.LogTrace("Loading cache from disk");
var json = File.ReadAllText(path);
cache = JsonConvert.DeserializeObject<Cache>(json, CacheContractResolver.Settings);
context.Logger.LogInformation("Loaded cache with stats: {stats}", cache?.GetCacheStats());
} catch (Exception e) {
}
catch (Exception e) {
context.Logger.LogError("Error loading cache: {exception}, creating new", e);
cache = null;
cache = Cache.CreateNewCache(version);
}

if (CacheNeedsInvalidation(cache, version)) {
context.Logger.LogInformation("Old cache found, ignoring");
cache = Cache.CreateNewCache(version);
}
}

CommonLib.InitializeCommonLib(context.Logger, cache);
context.Logger.LogTrace("Exiting InitCommonLib");
return context;
}

private bool CacheNeedsInvalidation(Cache cache, Version version) {
var threshold = DateTime.Now.Subtract(TimeSpan.FromDays(30));
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@mykeelium mykeelium Jul 11, 2025

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It might be valuable to make this value at least a constant.

if (cache.CacheCreationDate < threshold) {
return true;
}

if (cache.CacheCreationVersion == null || version > cache.CacheCreationVersion) {
return true;
}

return false;
}

public async Task<IContext> GetDomainsForEnumeration(IContext context) {
context.Logger.LogTrace("Entering GetDomainsForEnumeration");
if (context.Flags.RecurseDomains) {
Expand All @@ -178,7 +207,8 @@ public async Task<IContext> GetDomainsForEnumeration(IContext context) {
Forest forest;
try {
forest = dObj.Forest;
} catch (Exception e) {
}
catch (Exception e) {
context.Logger.LogError("Unable to get forest object for SearchForest: {Message}", e.Message);
context.Flags.IsFaulted = true;
return context;
Expand Down Expand Up @@ -224,7 +254,8 @@ public async Task<IContext> GetDomainsForEnumeration(IContext context) {
DomainSid = sid
}
};
} else {
}
else {
context.Domains = new[] {
new EnumerationDomain {
Name = domain,
Expand Down Expand Up @@ -315,11 +346,11 @@ public IContext Finish(IContext context) {
}

public IContext SaveCacheFile(IContext context) {
if (context.Flags.MemCache)
return context;
// 15. Program exit started. Save the cache file
// if (context.Flags.MemCache)
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@mykeelium mykeelium Jul 11, 2025 •
edited
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Do we support memcache? (not sure how it would work) If no, should we remove this line from readme? Also should we removed this commented out code if we are removing support?

// return context;
// // 15. Program exit started. Save the cache file
var cache = Cache.GetCacheInstance();
context.Logger.LogInformation("Saving cache with stats: {stats}", cache.GetCacheStats());
// context.Logger.LogInformation("Saving cache with stats: {stats}", cache.GetCacheStats());
var serialized = JsonConvert.SerializeObject(cache, CacheContractResolver.Settings);
using var stream =
new StreamWriter(context.GetCachePath());
Expand Down