In the realm of cryptography, handling and managing keys is a crucial task. The command provided is a series of operations using OpenSSL and other command-line utilities to extract and format an elliptic curve (EC) public key. Let’s break down the command to understand its purpose and functionality. The Command Extracting EC Public Keys with…
ECDSA keys are commonly used in various areas like blockchains. OpenSSL is a commonly used tools in Linux for handling signature/encryption/decryption. This post introduces how to generate ECDSA keys using OpenSSL in Linux. Generate keys for K1 secp256k1 elliptic curve We start with K1 (secp256k1) as the example. To generae ECDSA keys using other curves,…
This post summarizes Linux Kernel new features, bugfixes and changes in Linux 4.19.178 Release. Linux 4.19.178 Release contains 248 changes, patches or new features. In total, there are 239,909 lines of Linux source code changed/added in Linux 4.19.178 release compared to Linux 4.19 release. To view the source code of Linux 4.19.178 kernel release online,…
Hyperledger Fabric is a consortium blockchain system. It’s performance is relatively good and its modular architecture enables it to be usable in many scenarios. Hyperledger Fabric itself has rich documents and samples of test networks. For beginners, deploying a new network for trying and testing still consumes quite some time. In this post, we will…
RSA (Rivest–Shamir–Adleman) is a widely used public-key cryptosystem that is used for secure communication over the internet. In this post, we will explore how to generate a pair of RSA private and public keys in Linux using the OpenSSL library. Generating a pair of RSA private and public keys in Linux using OpenSSL is a…
How to encrypt a file using openssl on Linux non-interactively? The passphrase shall be provied to openssl in a programmatic way instead of requesting the user to input it, so that the command may work in a regular cron job or some batch jobs. To encrypt file file.tgz and store it to file.tgz using aes-256-ebc…
Admins usually need to generate some passwords for others, such as when creating a new user in a Linux system. How to generate a password in Shell on Linux? Several possible and short methods. Here, we generate a password of length 8. Using pwgen: $ pwgen 8 1 dao3PaW9 Password based on base64 (note that…
I am renewing my SSL key for my websites. The CA requests a CSR. I have my private key. How to generate a CSR (Certificate Signing Request) from a private SSL key? You can generate a CSR from your private key with openssl: openssl req -new -key ssl.key -out req.pem Here, ssl.key is your private…
VitualBox is installed on Fedora 21 by # yum install VirtualBox The following packages are installed kmod-VirtualBox-3.18.7-200.fc21.x86_64-4.3.20-4.fc21.4.x86_64 VirtualBox-4.3.20-3.fc21.x86_64 There is the kernel modules package installed. However, when running virtualbox (after reboot), it reports: [zma@laptop:~]$ virtualbox WARNING: The vboxdrv kernel module is not loaded. Either there is no module available for the current kernel (3.18.7-200.fc21.x86_64) or…
I got a password protected RSA private key with headers like (I have the password): —–BEGIN RSA PRIVATE KEY—– Proc-Type: 4,ENCRYPTED DEK-Info: AES-256-CBC,… How to decrypt a password protected RSA private key? You can use the openssl command to decrypt the key: openssl rsa -in /path/to/encrypted/key -out /paht/to/decrypted/key For example, if you have a encrypted…
Building Linux kernel may sound a complex and geek-only thing. However, as Linux kernel itself has much less depended tools/packages compared to other software packages, it is quite easy to compile, build and install a Linux kernel from the source code in an existing Linux OS. Building Linux kernel is needed if you need to…
As you may know, Adobe stopped supporting the NPAPI version of Flash on Linux and the latest NPAPI version of Flash player at version 11.2 released back in 2012 will only receive security fixes. Even the security fixes to the 11.2 version of the Flash Plugin your Firefox is using will end on May 4,…
If your website uses a self-signed certificates, Chrome will show a warning every time and you need clicks to continue. In this post, I will introduce how to make Chrome accept self-signed certificates for sites on Linux. This post is made short on purpose and you need to search the Web and learn if you…
ns is a discrete-event network simulator targeted primarily for research and educational use. There are two version of ns, ns-2 and ns-3, which are quite different with each other in the implementation and method to use them. In this post, we introduce how to install ns-2 and ns-3 on Fedora Linux 15. Install ns-2.34 on…