X.509 is just the format of the data. Certificates include a public key and a signature from a certificate authority (CA). On the web, typically web sites have a server cert that is issued …

Nov 19, 2014 · Edit #3: Ok, I figured the relationship between PEM and DER formats. The Base64 encoded payload of the PEM file is actually data in DER format. So initially the X.509 …

X.509 certificates are a generic, highly flexible format. SSL (now known as "TLS") uses X.509 certificates. A "SSL certificate" is a certificate whose contents make it usable for SSL (usually, …

Sep 25, 2020 · X.509 was initially issued on July 3, 1988 and was begun in association with the X.500 standard. X.500 is a series of computer networking standards covering electronic …

Feb 19, 2013 · Thus, X.509 is a way to distribute public keys, by which I mean: a method which allows various actors (e.g. you) to know, with some guarantee of non alteration by malicious …

Feb 16, 2016 · In X.509 certificates, the signature algorithm is protected because it is duplicated in the TBSCertificate.signature field with the proviso that the validator is to compare both fields …

Jul 11, 2022 · I understand how Key Usage Extension of x.509 certificate works. I have gone through the Key Usage section of RFC5280 and I know of all the valid values and what they …

Mar 22, 2019 · Is the serial number attribute of an X509 certificate Issuer or Subject, as defined in RFC5280, required to be the same as the Serial Number of the issuing or subject certificate?

Jul 24, 2015 · How can we identify which root CA client used when there are multiple root CAs on the server? We can compare the public keys of the client certificate and the root certificate but …

Jul 21, 2021 · The validity of a certificate can be shown by any tool that can parse / decode X.509 certificates: openssl x509 -text -in <certficiate.cer> You may have to add -inform DER if your …