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2

First, this is a pretty broad question already. Please don't add anymore questions to this and ask for further details in new questions instead. Question 1: Is this observation correct? No. If you do a openssl x509 -text -in cert.pem you can see the public key and also the type of the public key: ... Subject Public Key Info: Public Key ...


2

No, he cannot have recorded your traffic then decrypt it later. That takes an incredible amount of power and time. Could he have been able to see your traffic while you were there? Yes, using the methods you read about in the workplace questions you mentioned. Primarily by installing a certificate on your devices so that the lock would be there, but he was ...


5

Great question! I don't know if there's definitive source for this, so I'm going to make educated guesses based on the RFCs. TL;DR: the following keyUsage bits are supported in TLS 1.2 for end-entity certs: digitalSignature (0), keyEncipherment (2), keyAgreement (4), Now let's go through the keyUsages one at a time: ...


-1

At the end, I didn't had to rebuild it manually. I used wireshark and its automatic decryption tools to build the master key and extract the desired information.


2

It depends on many parameters, such as the encryption algorithm used, the specific mode being used, and the exact difference of data. For example AES uses block sizes of 16 bytes, and will always pad up to 16 bytes. Any message that is not a multiple of 16 bytes will therefore be padded up to 16 bytes. In your example with yes and no, this means that both ...


2

EDIT: I misunderstood the question, original answer below Standard HTTPS will protect everything from evesdroppers on the network; the POST data, any HTTP headers, cookies, even the URL that they are accessing. If your site has standard HTTPS, then you do not need extra encryption of the content. Yes, you can remove that extra call to ...


0

The SslBump feature in Squid allows the proxy to inspect the decrypted web traffic, but the tools on the Security Onion node (Snort, Zeek etc.) will still only see the encrypted traffic because they don't support passive TLS decryption. You will need to replay the proxied network traffic in decrypted form to a network interface in order to enable the tools ...


5

There's no way to guarantee the ability to listen to all TLS traffic from a given host. As you mention, the malware might not even use the system security store. It also might have a hard-coded certificate (or at least public key) that it is expecting, in which case it will notice any attempt at a man-in-the-middle attack unless you can steal the server's ...


3

Before I answer your questions, here are a few principles that will make the answers easier to understand. Keep network usage to a minimum. All transmissions are vulnerabilities. You are using the network to synchronize passwords between devices. All of the other functions should be performed locally on a cached database. Sensitive data should stay ...


5

As for example described in Wikipedia the PEM format requires a begin and end label, i.e. -----BEGIN CERTIFICATE----- and -----END CERTIFICATE----- . What you have here does not have such labels and thus cannot be PEM. It is instead a base64 encoded DER representation of the certificate, prefixed with the SHA-1 fingerprint of the certificate. I.e. what you ...


2

What is the relation of Peer signing digest with Signature hash algorithm (Certificate)? Peer signing digest is the algorithm used by the peer when signing things during the TLS handshake - see What is the Peer Signing digest on an OpenSSL s_client connection?. This is independent of the certificate. Signature hash algorithm (Certificate) is instead the ...


0

To have the same private key on both sides of a connection is the same as having a simetric key and is fine as long as the key distribution channel and storage are secure. I would suggest you to have different keys for the Kafka and java app even if you use the shared keystore. This will make easier to separate things in the future if necessary.


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There is no restriction in TLS itself which prevents using the same key pair on both sides of the connection. It is not really a good idea since a private key should be kept private (which it really isn't when shared between client and server) but it should nevertheless work.


3

You are mixing the concepts of authentication and authorization. The first is to know who the client is and the second to decide what this client can do. A client certificate in TLS is just used for authentication, i.e. like username + password but only better. If the service you want to access will accept this certificate as authorized is fully up to this ...


1

What you want is something very hard to achieve. Just ask most massive online multiplayer games about unnoficial clients. If the attacker can run the client on a device he controls, he can change the client's code to do whatever he wants. He can learn the protocol you use, and create another client implementing the protocol. SSL will not protect you, as he ...


2

Right now, we're concerned with an attacker getting around pinning and using a proxy to be able to open the html page (by getting its URL from the proxy) in a device browser (like Chrome) outside of the app Pinning is to ensure in the client that it connects to the right server. But it looks like that this is not your actual problem. Instead you are trying ...


1

.... ASN1_mbstring_ncopy:string too long:a_mbstr.c:158:maxsize=2 ^^^^^^^^^^^^^^^ ^^^^^^^^^ It is not about missing values but about an invalid value When reading the documentation you'll see that using prompt=no changes the interpretation of the values in the config: prompt if set to the value no this disables ...


4

You can pin leaf, intermediate CA, or root CA. All will work, but each comes with a usability / security tradeoff depending on the details of your setup. The article you link actually gives a fairly good run-down of the differences: Leaf certificate. By pinning against your leaf certificate you are guaranteeing with close to 100% certainty that this is ...


1

You could do both, you hash it at the client so if the attacker can get through the https security they will not be able to see the plain text password. Then hash it again at the server so if the attacker gets the passwords stored in the server he can not just send that to the server and gain access to the password.


2

Certificates only contain public keys for an asymmetric algorithm such as RSA or ECC. They do not contain symmetric keys, which is what operates using block ciphers in the various modes. Symmetric keys are established during the SSL handshake, and are based on the list of ciphers presented by the server and negotiated with the client at the time the ...


0

I'm not going to say "ignore them entirely", but this is pretty common. They're automated scans for logins - basically, anyone and their dog/cat/cow/python/rat can scan a site for common login URLs. If the scan finds them, then they'll usually probably try following up with credential stuffing attacks (i.e. using username/password combos that are either ...


0

If you are using OpenSSL below 1.0.2g 1.1.0m (both Nov. 2017) or 1.1.1 (Sep. 2018) there was a bug that did this -- see https://unix.stackexchange.com/questions/393601/local-ssl-certificates-in-chrome-ium-63/ -- and my workaround at https://unix.stackexchange.com/questions/371997/creating-a-local-ssl-certificate is to specify in the CA config section (your [...


-1

It seems that hotmail.com mail server sitting at hotmail-com.olc.protection.outlook.com How often do you send messages to (mailbox)@hotmail-com.olc.protection.outlook.com? Where did you get hotmail-com.olc.protection.outlook.com from? The certificate needs to match the MX record for the domain. When I check: $ nslookup > set type=MX > outlook....


2

The pros of using TLS 1.3 are that it is more secure. It mandates things like perfect forward security, removes support for insecure crypto-primitives like MD5, adds new more secure ciphers, etc. The cons of using TLS 1.3 is that it's so new (August 2018) that it's not often supported by underlying tools, and if it is it's often only supported under the ...


2

... what are these pros and cons of both and currently what is a better option? If TLS 1.3 is possible you should use it since it has a faster TLS handshake and encrypts not only the application payload but also parts of the TLS handshake like the certificate. TLS 1.2 is not insecure though, i.e. you can continue to use it. The best is currently to ...


-1

It's currently fixed (2020-01-11), Certificate chain is valid: mail.protection.outlook.com 128 days remaining / 2048 bit / sha256WithRSAEncryption GlobalSign Organization Validation CA - SHA256 - G3 2062 days remaining / 2048 bit / sha256WithRSAEncryption GlobalSign Root CA (Certificate is self-signed.) 2939 days remaining / ...


3

The handshake was integrity protected already in previous TLS versions. The early encryption is explicitly done to get more confidentially, especially to encrypt the certificate which is a major source of meta information in deep packet inspection. Server identity can still be leaked by other means such as server_name or SNI extension sent by a client. ...


3

TLS provides authentication with the use of certificates on its own. TLS actually can do a number of things, but is most commonly used for establishing an encrypted session/tunnel between two end points. It certainly can be used to provide authentication, but many of the EAP protocols that do make use of TLS only do so to encrypt the traffic between ...


3

For validating the certificate it is relevant that the domain in the URL matches the certificate. The certificate itself can be provided from any IP address, i.e. it does not have to be the public visible IP address but can also be a local one like 127.0.0.1. The mapping of domain to IP address is usually done by DNS but can also be done with a local hosts ...


2

TLS can provide mutual authentication with the use of public-key certificates. However, it is not necessary to use public-key certificates with TLS for authentication. TLS can be used solely to provide encryption (data integrity & privacy) for the data being transferred on the wire, without user authentication mechanisms. Often in TLS scenarios, only the ...


4

tl/dr: This company has no idea what they are doing. If you want to protect your data, the only option is to refuse to do business with them. Privacy and HTTP The first question is whether or not it is possible to communicate privately over HTTP. The answer is generally a solid "NO!". HTTP is a plain text protocol, which means that every server in ...


3

Yes, each extension defines what it means. A server that has never heard about this extension (e.g. the server is old and the extension is new) just disregards it, and the client must be ready to deal with that (at worst, by breaking the connection after ServerHello, but usually by falling back to the behavior before the extension was defined). The ...


0

While Steffen's answer is correct, knowing that this particular project is in the EU - it is actually possible to rely on Public CAs in Europe under the eIDAS standard. A qualified website authentication certificate (QWAC certificate) can be used for mutual TLS & Client Authentication. A CA (or Trust Service Provider) can grant these QWAC (x509) ...


2

What fields can I rely on in this case? It probably depends. But since there are fields in the subject for email, organization etc it is likely that these are actually filled in with the clients information. Would I be able to just map the Subject Name to a user in my application and trust the CA/Browser bundle? You should not just trust arbitrary ...


0

The error is because the client - postman - cannot verify the server certificate. My assumption based on the information you provided is that your organization's proxy acts as a Man-In-The-Middle and terminates SSL at the proxy. As a result, you recieve a certificate signed by your organization rather than something signed by a trusted certificate authority. ...


0

To verify that the server is the correct one and not some man in the middle TLS the server authenticates itself against the server. Usually this is done with certificates: here the server sends a certificate, proves (by signing some challenge) that it owns the private key for this certificate and the client checks if the certificate is valid for the server....


3

How is the PSK shared? A pre-shared key is, by definition, pre-shared. The term for this is that it is distributed out-of-band. In other words, the protocol does not prescribe a mechanism for sharing the key. It could be done using a logically-separate key agreement protocol, or by being generated from a shared secret hardcoded in both devices, or over a ...


5

Most websites intended for a general audience will want to select TLS versions based on security and browser compatibility. If you have guarantees that the clients used to connect to your website will be reasonably up to date, you may be able to depend on TLS1.3 alone. The optimal configuration for your website will depend on a number of parameters, and the ...


-2

As more vulnerabilities and exploits come out, an attacker can downgrade their communication method to exploit the older versions of TLS.


0

I see there are no Client Hello messages with the mail.yahoo.com name in the SNI extension field. Every ClientHello in both pcaps you've provided has a server_name extension with the name of the target server. There is no connection with a ClientHello for mail.yahoo.com in the second pcap though which matches your description. There are several other TLS ...


2

The origin is able to detect the server IP? Unless the socks server explicitly provides information about it (like adding an X-Forwarded-For header) the website cannot detect the originating IP address (what you call "server"). I don't have control over the agent (SOCKS5 server), how safe is this connection? The owner of the SOCKS5 server is able to see ...


0

@steffen-ullrich, your advice was helpful! I decode my sample traffic as some protocols in wireshark (because there was non-standard ports on traffic) and finally i found 'ServerHello message' and all information i needed!


2

These modules communicate with SSL (PSK) ... If these modules use SSL the encryption algorithm (AES, ...) and key length are encoded in the cipher used. Which cipher is used can be seen from the TLS handshake, notably the ServerHello message send by the server.


4

Below is a screenshot of an image search at the time of this discussion. The source image from the OP is referenced in numerous websites, and appears to be the subject of discussion due to the image content. The original image appears to be from a vpnMentor blog post: https://www.vpnmentor.com/blog/report-conor-leak/ Looking though https://crt.sh/?q=...


1

This is exactly the problem that protocols like PAKE and SRP aim to solve. With PAKE/SRP, the client and the server mutually authenticate each other based on a password known to both the client and the server. The client demonstrates to the server that it knows the password, without the client sending the password (or password-equivalent data) to the ...


60

The article states that: a connection was discovered to a web filter app built by Conor [Solutions] Given that it was a web filter, and given that it was able to log URLs, we can infer that this was a Man-in-the-Middle (MITM) proxy which decrypted the requests, filtered based on the unencrypted request, and then re-encrypted and forwarded the request to ...


-2

Unfortunately the days of a simple application Authentication and Authorization are gone. Authentication or trusting of just the end-user and not the server is the basis of Man-in-the-middle attacks. In today's threat environment there are no simple "safe" methods. There are three current Web Authentication and Authorization specifications that are proven ...


3

For example, hashing the password and the challenge together and sending it back to the server. The server would do the same with the user's stored password and check if both values are the same. In this scenario, the server would need to have the user's complete password, stored in plaintext or encrypted form. This introduces a security risk - if your ...


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