I am new to kubernetes. here I have some confusions about the CA certificates used in a kubernetes cluster. As far as I know there are several CA certificates in kubernetes, but still not clear what each functionality of them. Here is my understanding of them, but still not sure of them.
Root CA also know as serving CA,
it signs the apiserver certwhich are configured in the apiserver with --tls-cert-file and --tls-private-key-file.
this CA certificate is configured in kube-controller-manager with --root-ca-file
Client CA
this CA certificate can be a intermediate CA certificate signed by ROOT CA certificate.
which is used to sign the individual components in cluster, help to identify their identities when RBAC and NODE authorization are enabled. for example, sign the kube-controller-manager, kube-scheduler, kube-proxy, kubelet.
can be configured in apiserver with --client-ca-file
requestheader client ca
this CA certificate can also be a intermediate CA certificate signed by ROOT CA certificate.
Still not understand what this CA is used for ? what scenario of the CA file, just found that if metric server is deployed, it will ask for requestheader related certificates and keys
for --proxy-client-cert-file and --proxy-client-key-file in kube-apiserver, what the value of these parameter? can kubelet certificates and keys be used?
Besides these CA certificates, some other certificates relative confusions are also encountered.
--service-account-key-file parameter in kube-apiserver and kube-controller-manager, which file can be configured? is the apiserver key file or ROOT CA key file ?
what can be set to
--cluster-signing-cert-file and --cluster-signing-key-file in kube-controller-manager? can we use client ca and client ca key file?
A good summary is at https://github.com/kubernetes/kubernetes/issues/54665#issuecomment-340960398
The request header CA is used to verify a client cert presented by an authenticating proxy along with user info set in request headers. The proxy authenticated the user, proxies the request, and sets username/groups in headers. The API server verifies the client cert before trusting user info in any headers.
Related
According to TLS connection definition, for example, as the client-side, I use keystore to store my private key and certificate, and use truststore to store some kinds of certs. On the server-side, that call it Youtube, it has a root certificate called Youtube.pem which is signed by Google.crt CA.
I know the truststore is to verify the 3rd party certificate during handshake
My question is what should my truststore actually store during handshake?
Youtube.pem (the CA signed certificate sent from 3rd part)
Google.crt (the CA certificate)
According to TLS connection definition, for example, as the client-side, I use keystore to store my private key and certificate, and use truststore to store some kinds of certs.
Yes, but you only need a keystore if you want to use client side authentication. Note that "keystore" and "truststore" indicate how the store is used, they can be of the same type (e.g. PKCS#12) and even the same file.
On the server-side, that call it Youtube, it has a root certificate called Youtube.pem which is signed by Google.crt CA.
No, YouTube is a service, it has a leaf or end-entity certificate. The root certificate is that of a third party CA. The end-entity certificate is usually signed by an intermediate CA certificate, and that is in turn signed by a self signed root certificate.
I know the truststore is to verify the 3rd party certificate during handshake
It is used to validate and verify the trust path from leaf certificate to a trust anchor in your truststore. The trust anchor is usually one of the root certificates stored in your truststore. The leaf certificate is indicated by the end entity / server, the intermediate certificates are usually sent by the server as well, but they could also be retrieved from a cache.
In the case of YouTube, the Google root CA is used, possibly using the GlobalSign root through a linked certificate if the Google root is not present in the trust store.
So your truststore should either contain the Google root certificate or the GlobalSign root for the connection to work in this example.
I have the company CA signed certificate, intermediate and server certificate in the identity store ( .jks) but still the browser says , cannot be verified by a trusted authority error. Using weblogic -10.3.1 from the weblogic logs i also notice this -
Invalid/unknown SSL header was received from peer x.y.z.12 during SSL handshake
But when I install the root and intermediate certificates into certmgr.msc then when i access the url again in a new window it has no error on the browser and also no error log in the weblogic server.
What could be wrong ?
Global CA's have their root and intermediates recognised by all the modern browsers. However when browser encounter s a certificate whose intermediate and roots aka chain certificates & ca certificates are not a part of its trust store so it fails to chain the leaf certificate to its issuer. So in order to mitigate thi, the roots and intermediates of the company ca must be added so that the browser can verify the complete chain.
Agreed .but thats how the trust works. The company issues ca certificate is known only to your organization but browsers are accessed globally and if you want make the certificate trusted in all the browsers then either you switch to public ca issued certificates or get your root certificate cross signed by a global ca root.
When a TLS handshake takes place, the server sends in his ServerHello message, his digital certificate. This digital certificate is digitally signed by a intermediate CA named A and CA A also has a certificate which is signed by CA named root whose certificate is self signed, thus forming a certificate chain. The client then has to establish a trust, validating the server certificate. To perform that validation the client has to validate the entire chain correct?
Must the client have in a truststore all the certificates (A and Root) or the client will download them?
The client usually has only the root CA in the local trust store. The leaf certificate and the intermediate certificate leading to the root CA need to be provided by the server. The intermediate certificates are usually send in addition to the leaf certificate within the TLS handshake.
But it is a typical misconfiguration to only have the leaf certificate send by the server. In this case the certificate validation will fail unless the client has already knowledge of the intermediate certificates or can obtain these somehow. Since often the same intermediate certificates are used, some browsers like Firefox will cache the intermediate certificates they'll got when communicating with server A and fill these in when a broken server B is not sending the required intermediate certificates. Other browsers (like Google Chrome) will try to download the missing intermediate certificates from the internet. Most simpler clients (i.e. apps written in Python, Java ... or curl) will instead just fail with a certificate validation error.
I am trying to set up 2 way ssl mutual authentication for my web application. I currently haven't set up my client and am testing my web service through my browser.
I created a client certificate using the keychain tool on my mac and import the certificate.p12 file in Firefox. I also have a certificate.cert file. From my understanding I need to add this cert file in my servers truststore.
For that I need to using the following command:
keytool -import -trustcacerts -alias <hostname of DP> -file <your file.crt> -keystore <truststorefile>
However what do I add as the hostname of my system? What will the browser show the hostname as to my webserver?
First if you have client cert(s) issued by either a well-known CA (like Verisign, GoDaddy, etc) or a locally-trusted one (like your employer), you don't have to do anything. The client will simply present the cert with a chain that leads to the already-trusted CA.
If you have issued client certs from your own CA, you should add the CA (root) cert only to the server truststore. Then all client certs issued by that CA will be validated without further effort. If you make the CA cert long-lived, as is the usual practice, you can even renew and/or replace client certs with no effort on the server. And you can automatically revoke them if you set up CRL distribution and/or OCSP, although DIY CAs don't always want to go to that effort.
If you have created a self-signed client cert, then and only then you need to add that specific cert to the server truststore. Although SSL/TLS server certs must be identified by the hostname(s) of the server, client certs are not required to, and CA certs (which are the certs usually in your truststore by default) never have a hostname as the Subject (although some extensions usually contain URLs that contain hostnames). Codesigning certs also don't need to use a hostname.
The alias of a cert entry in a Java truststore does not need to be the hostname; it only needs to be unique, although it should be mnemonic of the subject of the cert. If for example your client certs are for users named Alice and Bob (or more likely their PCs or whatever devices) you can just use alice and bob as the aliases.
We have an Azure web role deployed that uses HTTPS. We upload a certificate to azure and shortly after the portal refreshes and two more certificate appear. This is not a wild cart certificate and maybe this is standard behavior, but I haven't seen it before.
The original certificate is named something like:
subdomain.domain.com
The three certificates that appear are named like so:
VeriSign Class 3 Public Primary Certification Authority - G5
Class 3 Public Primary Certification Authority
VeriSign Class 3 International Server CA - G3
Are the 3 certificates I mentioned normally generated or is this an issue I should be looking into?
We have a similar deployment that has an ssl, but does not generate these extra certificates. This is what triggered our concern and has me asking why ...?
When you enabled HTTPS endpoint in any web application and bind SSL certificate to it, the certificate bind to HTTPS endpoint is could be a single certificate or it could be a chain and
it is depend on several factors as below:
When the certificate is created as self signed ROOT then it will have only one certificate in the chain. This certificate can not be validated to have SSL tunnel because there is no other part to verify it and that why it is called self signed root
When you buy certificate from a reputed CA (Certificate Authority) in almost all cases you will get 3 (or more) certificates:
2.1. Root Certificate : This certificate is helps to create a SSL tunnel between two machines using PKI security Infrastructure.
2.2. Intermediate Certificate -> This is to create a chain with multiple certs as if needed
2.3. Domain Certificate -> This is for your *.domainname.com or domainname.com
Here is an example of chained SSL certificate at https://mail.google.com
And all of these certificate are chained into one single PFX (if private key embedded into certs) or CER (without any Private Key) so when you deploy only ONE PFX cert, you see the chain is open and all certificates are listed.
If you browser your url and open the certificate view through browser, you will see exactly same chain as you could see in your portal and you can also verify the certificate thumbprint as well to match.