Developer guides and tutorials

Catastrophic Regex Backtracking in .NET: Timeouts and Safer Patterns

How nested quantifiers like (a+)+ cause exponential regex time in .NET, measured on .NET 8, with fixes: match timeouts, NonBacktracking, safer patterns.

Base64 vs Base64URL in .NET: When + and / Break URLs

Base64 can contain + and /, which behave differently in URL paths and query strings. Tested ASP.NET Core examples and the Base64URL fix.

JWT Clock Skew in .NET: Fixing IDX10222 (Token Not Yet Valid)

Why a valid JWT is rejected as not yet valid when clocks differ, how ClockSkew works (default 5 minutes), and how to backdate nbf. Tested on .NET 8.

DateTime vs DateTimeOffset in .NET: Comparison Pitfalls

DateTime comparison ignores Kind, so Local, Utc and Unspecified compare by ticks. Tested examples, the Unix-timestamp trap, and the DateTimeOffset fix.