Skip to content

Address feedback: enforce Azure DLL public key token at bind time under STRONG_NAME_SIGNING #3983

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
paulmedynski merged 2 commits into from
Feb 25, 2026
Merged

Address feedback: enforce Azure DLL public key token at bind time under STRONG_NAME_SIGNING #3983

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
83f6647
Initial plan
Copilot Feb 25, 2026
c27acee
Load Azure extension assembly with public key token under STRONG_NAME…
Copilot Feb 25, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
27 changes: 10 additions & 17 deletions ...Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/SqlAuthenticationProviderManager.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -55,7 +55,17 @@ static SqlAuthenticationProviderManager()
try
{
// Try to load our Azure extension.
#if STRONG_NAME_SIGNING
// When strong-name signing is enabled, build a fully-qualified AssemblyName
// that includes the expected public key token. The runtime then enforces the
// token during binding, so an untrusted assembly with the same simple name
// is never loaded (and its module initializers never run).
var qualifiedName = new AssemblyName(assemblyName);
qualifiedName.SetPublicKeyToken([0x23, 0xec, 0x7f, 0xc2, 0xd6, 0xea, 0xa4, 0xa5]);
var assembly = Assembly.Load(qualifiedName);
#else
var assembly = Assembly.Load(assemblyName);
#endif

if (assembly is null)
{
Expand All @@ -66,23 +76,6 @@ static SqlAuthenticationProviderManager()
return;
}

#if STRONG_NAME_SIGNING
// When assembly strong name signing is enabled, check the public key token, which
// gives us a mediocre level of confidence that this assembly is actually ours.
byte[] expectedToken = [0x23, 0xec, 0x7f, 0xc2, 0xd6, 0xea, 0xa4, 0xa5];
byte[]? actualToken = assembly.GetName().GetPublicKeyToken();

if (actualToken is null || !actualToken.AsSpan().SequenceEqual(expectedToken))
{
SqlClientEventSource.Log.TryTraceEvent(
nameof(SqlAuthenticationProviderManager) +
$": Azure extension assembly={assemblyName} has an " +
"unexpected public key token; " +
"no default Active Directory provider installed");
return;
}
#endif

SqlClientEventSource.Log.TryTraceEvent(
nameof(SqlAuthenticationProviderManager) +
$": Azure extension assembly={assemblyName} found; " +
Expand Down
Loading