10
Digital Certificates and Certification Authorities
In the previous two chapters, we discussed the nuts and bolts of public key cryptography and digital signatures. In the current chapter, we delve into the details of the infrastructure needed to verify the authenticity of public keys. We will see that digital signatures play an important part in this: digital certificates are digitally signed documents, where a trusted third party warrants that a public key belongs to a certain entity, whereas certificate authorities are the entities responsible for issuing certificates. More precisely, we will look at so-called X.509 certificates including the following:
Data fields
Enrollment
Revocation
Trust model
After describing the format of a digital certificate and the processes needed to issue and verify a certificate in general, we turn to RFC 8446 and describe the usage of certificates and certificate authorities within TLS. Here, you will learn the following:
What TLS extensions look...
