Posts on this page:
Yesterday I pushed new PSPKI release with version number v3.3.0. New version is even more stable and even more powerful. More technical change list is moved to dedicated article: Release notes for PSPKI v3.3.0. In this (and, possibly next) blog post I would like to outline major changes/improvements to this release.
I bet that ADCS database access is one of the most popular features people love in my module. And there are reasons: I put a lot of efforts to simplify access to CA database and provide flexible filter options. For example, get certificates that will expire in next 30 days:
Hello world! Last time (year or so) I was busy on anything else but my module. Now I’m happy to announce that the project isn’t died, it is alive and new version is published.
This version doesn’t bring new commands, nor deprecate any. I think, command list is well-established and I don’t see anything useful to add. People doesn’t ask either. However there are things to work with code: refactor, optimize, make it cleaner and so on. Let’s look at what I’ve done here:
Initially, project was hosted at CodePlex which is died now. I moved all my sources to GitHub, documentation to my web site and used CodePlex as module download place.
Since CodePlex is done, the only real option to ship binaries was to use PowerShell Gallery. It is something new to me (I never used it till today) and was a bit lost there. But it appeared more easier than I thought. Starting with v3.2.7, the module is available on PowerShell Gallery: PSPKI. Please, provide feedback on your experience with getting PowerShell PKI module from gallery.
In the past, I used MSI installer to ship the module. It is still very good option to do that, because you can use various tools, like group policies or ConfigMgr to deploy the module within organization. Thanks to Caphyon Advanced Installer and their free NFR license (as a part of my Microsoft MVP award) I was able to do that. And their tool was really great and easy to use. However, my MVP award options are uncertain and PowerShell Gallery is an acceptable tradeoff, so there is no big need in MSI anymore.
Hey guys! I was silent for a while due to a lack of good topics to discuss. Today I want to present another piece of my class work at university for “Compiler Development” course. The task is to write a manual lexical parser for a language of my choice. I decided to take JSON language, because its syntax is relatively simple and requires most common techniques to parse. In addition, it has well-looking BNF grammar for custom parser implementations.
The purpose of lexical analysis is to read the source code and convert them to a sequence of tokens (lexemes) which are minimal parts of each language. It is important understand that lexical analysis doesn’t perform semantic (meaning) validation. That is, lexical analysis determines whether the source code can be written in a specific language’s alphabet. It doesn’t mean that the code will be executed successfully. Source code semantic is validated only after lexical analysis and uses its product (a set of tables, keywords, operators, literals, identifiers, etc.).
You can think that there is no need to write your own lexical parser, because there are LOTS of them. For example, PowerShell contains built-in JSON encoder and decoder via ConvertTo-JSON and ConvertFrom-JSON cmdlets. Though, these cmdlets completely hide parsing result and perform object conversion. You can’t access internal parser to look at exact results of the parsing. But results of lexical parsers are actively used in web. For example, JS-based syntax highlighters use lexical parser to split the source code into tokens and colorize or highlight them for better readability. And my website does it as well (though, not via JS). For example, all XML and PowerShell code snippets on my blog are colorized by using lexical parsers. For PowerShell code I’m using Tokenize method in System.Management.Automation.PSParser class. For XML strings I’m using custom XML tokenizer. And cororize them according to token types.
Hello blog readers!
Here is another tl;dr; blog post! Yesterday I completed my winter exam session at university and want to recall one interesting work I had year ago at the course called “Data structures and algorithms” where we learned various data structures and manipulation algorithms. During the course we developed them in programming languages with further analysis. In array search class work I had to implement, analyze and compare two search methods: sentinel search and hash table search.
Most search algorithms have complexity. This means that their performance depends on array size. Larger is array, more time is required to find element in array. There is binary search that gives which better than linear, but still depends on array size and requires sorted array. Binary search is impossible for unsorted arrays. What next? Next is search algorithm that would give us constant complexity. This means that regardless of array size, search will be completed in constant time. This algorithm (actually, data structure) is hash table.
What is hash table? It is an associative array that maps keys to data values. Unlike classic arrays, there is no such term as array index, instead there used term key value. Key is an identification information about data value. During class work I learned a lot about hash tables and faced a number of very interesting challenges while attempting to develop a reliable implementation of hash table. And this blog post will reveal all of them!