Is there a way to secure the transport layer without any server certificate?
I read RFC 4492 and it is saying there is a key exchange algorithm name ECDH_ANON which does this, but on many of the links I found that it is not recommended to use this as it is prone to MITM (Man in the Middle) attack.
I just want to mention that my server is not public and my server and clients are in the same local subnet. My server is accepting connection on websocket.
What are the options if I want to secure my transport layer? I don't want to do it by manually encrypting the payload.
You could use a solution called TLS-SRP, if supported by your server and client(s). But probably more common is to just install a self-signed server certificate for your local system, or set up your own CA and issue your own cert to the server and install the CA's root cert as a trusted root on your clients.
Related
A Certified Domain should be accessible only if SSL public certificate of the domain is already present in client's trust store. If not, client should prompt to import server certificate instead of getting it from tomcat server automatically(Via SSL handshake)
This will not work: the server has no knowledge which CA certificates are known to the client so the server cannot decide what to send to the client. Also, the server can only send a certificate to the client but not make the client import a new root CA - no matter if with or without prompt.
Apart from that it makes no sense: the idea of TLS/HTTPS is that the client will only connect to a server which identity can be verified. If the server can make a client import a new trusted root CA an attacker could do the same and thusman in the middle attacks would be possible.
If one instead just want to know if the client will trust a specific certificate or not one could include a resource (image, script...) served with this certificate into a known good HTML page and then check with some script in the page if the resource was loaded successfully. This check could also result in a redirect of the client, for example to some page describing the problem and linking to the correct root CA.
I am rather confused by the purpose of the trustore file in a tomcat server.
I.e use of the truststoreFile parameter when setting up a TLS enabled connector.
According to the tomcat docs:
truststoreFile
The trust store file to use to validate client certificates. The
default is the value of the javax.net.ssl.trustStore system property.
If neither this attribute nor the default system property is set, no
trust store will be configured.
To me this is telling me that for an inbound connection to my tomcat server, this is where I would store certificates that a client would present. (e.g. a users browser)
Would I really put in 3rd party CA certificates here or other 3rd party server certificates, if my tomcat server wants to make an outbound connection to a TLS enabled server (e.g. an LDAPS server)
As per my understanding the place to do this is the cacerts file.
Is my understanding of the truststore wrong?
Yes, you are right, it is quite confusing.
If you need to make an outbound connection a 3rd party, you need to add the certificates to cacerts.
There is a very popular "signing, validation, etc." service for government-owned companies here in Spain, #firma, that just changed its wildcard server certificate and we had to add it to cacerts.
There are several questions on stackoverflow regarding Akka, SSL and certificate management to enable secure (encrypted) peer to peer communication between Akka actors.
The Akka documentation on remoting (http://doc.akka.io/docs/akka/current/scala/remoting.html)
points readers to this resource as an example of how to Generate X.509 Certificates.
http://typesafehub.github.io/ssl-config/CertificateGeneration.html#generating-a-server-ca
Since the actors are running on internal servers, the Generation of a server CA for example.com (or really any DNS name) seems unrelated.
Most servers (for example EC2 instances running on Amazon Web Services) will be run in a VPC and the initial Akka remotes will be private IP addresses like
remote = "akka.tcp://sampleActorSystem#172.16.0.10:2553"
My understanding, is that it should be possible to create a self signed certificate and generate a trust store that all peers share.
As more Akka nodes are brought online, they should (I assume) be able to use the same self signed certificate and trust store used by all other peers. I also assume, there is no need to trust all peers with an ever growing list of certificates, even if you don't have a CA, since the trust store would validate that certificate, and avoid man in the middle attacks.
The ideal solution, and hope - is that it possible to generate a single self signed certificate, without the CA steps, a single trust store file, and share it among any combination of Akka remotes / (both the client calling the remote and the remote, i.e. all peers)
There must be a simple to follow process to generate certificates for simple internal encryption and client authentication (just trust all peers the same)
Question: can these all be the same file on every peer, which will ensure they are talking to trusted clients, and enable encryption?
key-store = "/example/path/to/mykeystore.jks"
trust-store = "/example/path/to/mytruststore.jks"
Question: Are X.509 instructions linked above overkill - Is there a simple self signed / trust store approach without the CA steps? Specifically for internal IP addresses only (no DNS) and without an ever increasing web of IP addresses in a cert, since servers could autoscale up and down.
First, I have to admit that I do not know Akka, but I can give you the guidelines of identification with X509 certificates in the SSL protocol.
akka server configuration require a SSL certificate bound to a hostname
You will need a server with a DNS hostname assigned, for hostname verification. In this example, we assume the hostname is example.com.
A SSL certificate can be bound to a DNS name or an IP (not usual). In order for the client verification to be correct, it must correspond to the IP / hostname of the server
AKKA requires a certificate for each server, issued by a common CA
CA
- server1: server1.yourdomain.com (or IP1)
- server2: server2.yourdomain.com (or IP2)
To simplify server deployment, you can use a wildcard *.yourdomain.com
CA
- server1: *.yourdomain.com
- server2: *.yourdomain.com
On the client side you need to configure a truststore including the public key of the CA certificate in the JKS. The client will trust in any certificate issued by this CA.
In the schema you have described I think you do not need the keystore. It is needed when you also want to identify the client with a certificate. The SSL encrypted channel will be stablished in both cases.
If you do not have a domain name like yourdomain.com and you want to use internal IP, I suggest to issue a certificate for each server and bound it to the IP address.
Depending on how akka is verifying the server certificate, it would be possible to use a unique self-signed certificate for all servers. Akka probably relies trust configuration to JVM defaults. If you include a self-signed certificate in the truststore (not the CA), the ssl socket factory will trust connections presenting this certificate, even if it is expired or if the hostname of the server and the certificate will not match. I do not recomend it
Sim800 supports SSL protocol. AT command "AT+CIPSSL" sets TCP to use SSL function.
In the "sim800_series_ssl_application_note_v1.01.pdf" is noted that: "Module will automatic begin SSL certificate after TCP connected."
My Problem: What is the exact meaning of the begin SSL certificate? what does sim800 do exactly? Does sim800 get SSL certificate from website? where does sim800 save SSL certificate?
As far as I know, SIM800 has some certificates in it and when you use a TCP+SSL or HTTP+SSL connection it will automatically use those certificates.
If those certificates are not ok for you, you will need to use an SD card, save there the certificates you want and use the command AT+SSLSETCERT to set the certificate you saved on your SD card. Here you can find how to use the File System.
Usually the certificates that come with the module are enough and you won't need this. But for example they didn't work for me when I tried to communicate with Azure via MQTT. I had to encrypt the data myself using wolfSSL library and send it using TCP without SSL.
Note: Not all SIM800 modules have SD card support.
There are a very few information about sim800 and ssl certificate on the web, and like you i got a lot of questions about it.
About your questions on how does sim800 get certificate and where does it save it, it seems, according to sim800_series_ssl_application_note_v1.01.pdf, that you can create (defining your own path), write and import a ssl certificate on your own with the AT+FSCREATE, AT+FSWRITE and AT+SSLSETCERT commands. An example is provided at the paragraph 3.10.
I'm sorry, i can't answer your other questions.
Anyway, if you get further informations about sim800 and ssl, i would be grateful if you share it with me.
When you use AT+CIPSSL you tell the SIM-module to use the SSL connection with TCP. When you use +CIPSTART command->
SIM module requests the TCP connection with the server through SSL.
Server sends the Server SSL certificate.
The authenticity of that certificate is checked with internal certificate authority certificate (The one that resides inside SIM-module) which is cryptographically connected with server certificate.
If the authenticity of certificate can not be confirmed SIM-module will close the connection unless you use the command AT+SSLOPT=0,0 (which forces the SIM-module to ignore invalid certificate authentication) prior to AT+CIPSSL command.
//Key exchange
SIM-module then encrypts it's master key (already inside SIM-module cannot be changed or read) with the public key (Which is part of the already sent server certificate) and sends it back to server.
Server then encrypts it's master key with SIM-module's master-key and sends it back to SIM-module. Key exchange is now complete as both (server and SIM-module) recieved master keys.
SIM-module currently doesn't support Client authentication which means that server cannot authenticate the client. That means there must be some other option of authentication (For example in MQTT that can be username and password that only client knows)
If you want your module to be able to authenticate server you will need to create the self-signed certificate for server and certificate authority certificate (for SIM-module) which is cryptographically connected to self-signed certificate and upload them to server and SIM-module (through AT+SSLSETCERT command from SD card).
If you only want to encrypt the data traffic you can ignore invalid certificate (AT+SSLOPT=0,0) as you will recieve publickey nevertheless. But if you want to be sure about server authenticity you will need to upload right certificate to module.
1) I am trying to setup an FTPS server on my EC2 Ubuntu instance. I can only find resources to setup tutorials for an SFTP server.
2)From what I understand, the SSL certificate is only applicable to the server. When a user tries to FTPS to my server, should he/she upload a certificate or public/private key file similar to SFTP? Or only hostname, port, username, password is sufficient?
You might have better luck searching for "ftp over tls" which is another name for ftps. TLS is the successor protocol to SSL, though often still referred to casually as "SSL."
I use proftpd and I mention that primarily because their docs discuss some theory and troubleshooting techniques using openssl s_client -connect which you will find quite handy regardless of which server you deploy.
The SSL cert is only required at the server side, and if you happen to have a web server "wildcard" cert, you may be able to reuse that, and avoid purchasing a new one.
Client certs are optional; username and password will suffice in many applications. Properly configured, authentication will only happen over encrypted connections. (Don't configure the server to also operate in cleartext mode on the standard ftp port; inevitably you'll find a client who thinks they are using TLS when they are not).
If client certs are required, it is because of your policy, rather than technical reasons. You'll find that SSL client certs operate differently than SSH. Typically the client certs are signed you a certificate authority that you create, and then you trust them because they are signed by your certificate authority as opposed to your possession of their public key, as in SSH.