Understanding PKCS8 vs PKCS1 vs PKCS12

PKCS8 is the eighth of the Public-Key Cryptography Standards (PKCS) and is a syntax for storing private key material. The private keys may be encrypted with a symmetric key algorithm. If the usage of your key requires it to be in plain text, make sure it is stored in a secured location. If at all […]


Error message: [email protected]:~$ ssh-add david/.ssh/id_rsa @@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: UNPROTECTED PRIVATE KEY FILE! @ @@@@@@@@@@@@@@@@@@@@@@@@@@ Permissions 0775 for ‘david/.ssh/id_rsa’ are too open. It is required that your private key files are NOT accessible by others. This private key will be ignored. [email protected] Understanding id_rsa Private Key File ~/.ssh/id_rsa Contains the private key for authentication. These files […]

How to fix unable to load Private Key

OpenSSH has its own Private Key format. It doesn’t match with OpenSSL. But We can create or convert to a Openssl style private key. Error message: ssh-keygen -t rsa -b 4096 openssl rsa -in ~/.ssh/id_rsa -outform pem > id_rsa.pem unable to load Private Key 140735944156104:error:0906D06C:PEM routines:PEM_read_bio:no start line:/BuildRoot/Library/Caches/com.apple.xbs/Sources/libressl/libressl-22.50.2/libressl/crypto/pem/pem_lib.c:704:Expecting: ANY PRIVATE KEY   Understanding OpenSSH key […]

How Encryption works with Private Key and Public Key

Each private key has a corresponding public key. Generally, the public key can be easily derived from the private key, but deriving the private key from the public key is computationally infeasible. In a public-key cryptosystem, a public key is a key that can be used for verifying digital signatures generated using a corresponding private […]

Check Root CA Certificates in Linux

Root certificate is the first link in the chain of trust, . Unlike other certificates, it is self-signed, meaning the issuer and subject are the same. It is a kind of X.509 certificate that can be used to issue other certificates. Certificate authorities (CAs) adhere to strict requirements to merit the trust of having a […]

Check SSL Encryption in Linux

SSL encryption applies two keys named Public key and Private Key to encrypt connection. Both keys are similar in nature but their usage is different. Even these keys length may vary in terms of bits. The more the key is lengthy; it is hard to break it. The receiver uses public key to encode the […]

5 ways to Fix invalid SSL certificate Error

An invalid SSL certificate can be one of the worst things for our business. With its scary warning messages showing in the browser, it can make people run away from our site like nothing else. Therefore, we should fix it at the earliest. And hopefully, we will not have any trouble fixing it now when […]

2 Ways to Check TLS Certificate expiration Date with OpenSSL Command

We can quickly solve TLS or SSL certificate issues by checking the certificate’s expiration from the openssl command line. Today, let us see how to check certificate’s expiration date in 2 ways. The first one is to check the certificate on remote server side. The second is to check the certificate by PEM files. Check […]

Convert SSL Cer to PEM by OpenSSL

There are two major encoding schemes for X.509 certificates and keys: PEM (Base64 ASCII), and DER (binary). DER (Distinguished Encoding Rules) is a data object encoding schema that can be used to encode certificate objects into binary files. PEM (Privacy Enhanced Mail) is an encrypted email encoding schema that can be borrowed to encode certificate […]

Create SSL Certificate With OpenSSL Command

A self-signed SSL certificate is a security certificate that is not signed by a certificate authority (CA). These certificates are easy to make and do not cost money. The Self-signed SSL certificate is mainly used for non-production applications or other experiments. Generate private key and self signed SSL certificate Run the following OpenSSL command to […]