Category Archives: Linux

Linux mixed reality

The GPG_TTY environment variable or github commit problem

I used a lot of different source control systems: SVN, CVS, Rational ClearCase, Perforce Helix, Bitbucket and others. Currently I am on github. Github looks indeed complex, even after Bitbucket which is based on git solution as well. Recently I cloned my repository on new Azure Linux virtual machine, everything was OK until commit step.… Read More »

Get Thumbprints from Windows Catalog File on Linux

This article is related to the “Windows Catalog Files” post and describes how to parse catalog file using posix c++ on Linux platform. On Windows as it is mentioned in “Windows Catalog Files” it is possible to retrieve thumbprints with mscat.h API. The Linux parsing method is based on searching positions of some OIDs… Read More »

Alice, Bob and Asymmetric Cryptography

I suppose a lot of people know about Alice and Bob, the characters of many cryptographic tales. Previously I posted article “Encrypt and Decrypt Data on Linux Devices using OpenSSL” which explains how encrypt and decrypt files in symmetric way, currently I want to do the same using asymmetric cryptography, exactly how Alice and Bob… Read More »

Experimenting with ECB and CBC Ciphers of AES

The openssl help shows 2 groups ciphers with ECB (Electronic Code book) and CBC (Cipher Block Chaining) suffixes. For example aes-128-ecb and aes-128-cbc or aes-256-ecb and aes-256-cbc for AES (Advanced Encryption Standard) ciphers. In ECB mode input data is divided in blocks of the same length. Then every block will be encrypted with the same… Read More »

Changing Certificate Verification Flags in openssl

Recently I was needed to modify some flags for verification of X.509 public key certificates. These flags defined in x509_vfy.h include files. Particularly it was necessary to set X509_V_FLAG_X509_STRICT flag, which enables additional security checks and turns off workarounds for broken certificate chain. In other words this flag makes the certificate verification more strictly. This… Read More »

About dladdr function.

dladdr function from Unix-like OS looks similar as GetProcAddress Win32 API function. However dladdr obtains more information related to requested function than function entry point address as GetProcAddress does. Besides GetProcAddress requires the handle of the DLL module that contains the requested function, dladdr needs only the function name. Definitely in both cases DLL or… Read More »

Apache on CentOS and HTTP -> HTTPS redirection

Apache HTTP server is a free, open source and popular web Server. It is cross platform server that may run on Linux, Windows and other operating systems. This post is about Apache installation and configuration on CentOS 8. I wrote it for myself as a reminder for future own references. Apache is available in CentOS… Read More »

Installing swift on CentOS 8

Previously I worked with swift occasionally and using xCode only. There is my previous post with XML parser written in swift language. Here is my experience in swift installation on Linux platform with initial command line programming example. The first step – swift installation: It takes several minutes. Check swift version: # swift –version Swift… Read More »

Signing Windows PE file on Linux

The first question is: what for? There are a lot of reason for example someone download Windows application from Linux Apache server. The downloaded application is signed in runtime with different certificate according to selected license. Later during execution Windows application checks certificate type, revocation status and blocks or grants some features. Also application may… Read More »