Questions tagged [x.509]

X.509 is a standard for a public key infrastructure used for authentication and access control. X.509 specifies standard formats for certificates, revocation lists, attribute certificates, and path validation.

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1answer
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Why is there no certificate error while visiting google.net although it presents a certificate issued to google.com?

The following output shows that google.net is presenting a certificate that has been issued to www.google.com. $ openssl s_client -connect google.net:443 < /dev/null > out.txt 2>&1; cat ...
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1answer
996 views

Is it possible to create GnuPG keys from a x509 cert/key pair?

I have a digital cert issued by my organization for signing email. It's imported into Thunderbird and the key and cert can be exported to a .p12 from within Thunderbird. I'd like to use the .p12 to ...
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1answer
883 views

Can an SSL certificate be used to generate a SAML token

An external application (B) requires a SAML token to allow users who log into my application (A) to access it directly without having to log in again. This access is not built yet. My organization has ...
0
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1answer
847 views

Self Signed SSL Certificate - How to verify it correctly on the client side?

For our current implementation we are using a self signed root certificate, which then is used to sign ssl certificates for our secure http connection. My question relates to the verification logic ...
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0answers
93 views

What is a KEA certificate and how it is used?

I'm currently studying IKE and IPsec in the context of VPN applications and I know that a X.509 certificate is used to provide server's public key to the client (and vice-versa in case of mutual ...
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1answer
891 views

What's the state-of-the-art approach to secure a backend API?

Scope Currently we are developing a backend REST API which is consumed by handful of MVC applications. In this case we are talking only about server-server communication and the API won't be consumed ...
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1answer
211 views

How is a certificate extension different from a certificate file name extension?

The following article has explained both differently. X.509 wiki Now my question is: Can we use more than one extension in a certificate? Is it how there can be more than one use of extensions in a ...
0
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1answer
113 views

Is the windows root trust store used by IE?

With the Symantec-Google drama, it would help to know if the Internet Explorer browser has its own root trust store built in to the browser, or uses the automatically updating Windows System root ...
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3answers
1k views

ASN.1 encapsulated BITSTRING type in openSSL

I am currently building an ASN.1 parser which supposed to decode X.509v3 certificates and epoch files in ASN.1 DER format. The parser is working well apart from one issue which I couldn't seem to get. ...
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1answer
149 views

Verification and authentication flow for X509 code-singing certificate

I am developing an embedded devices FW updates (not connected to the internet) and I am using code-signing certificates in order to verify the FW update issuer identity (the FW update is signed with ...
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2answers
879 views

CA signature algorithm vs certificate public key algorithm

Is there any restriction on the CAs signature algorithm with respect to the public algorithm in the actual server/device certificate? For example, can a ECDHE_ECDSA_* certificate be signed by a CA ...
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3answers
5k views

Why does generating a self-signed X509 certificate not require my public key?

Let's say I have an RSA (2048) keypair that I generated private.key public.key For testing purposes I'd like to generate a self-signed X509 certificate. My understanding of a certificate is that it ...
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3answers
1k views

Can X.509 Authentication be subject to brute force attacks?

I am working on an application (using Spring Security) that has two possible user authentication mechanisms: either X.509 certificate (using mutual SSL handshake) or user + password For user+...
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4answers
25k views

IP address in SubjectAltName

Is it allowed to specify IP as DNS name for SAN certificate ?
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1answer
96 views

Building a “Hello, world!” X.509-based system for establishing trust between servers

I want to build a distributed software system with the following elements: A number of workers, which manage potentially sensitive data and execute code on behalf of a number of clients. A number of ...
2
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1answer
250 views

Does X.509v3 certificates prevent MITM attacks in SSH

I was reading RFC 4251 (really all of the SSH RFCs) and in section 9 it goes into great length about security considerations listing 3 cases of MITM attacks. In several places in the RFCs the authors ...
2
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1answer
873 views

Signature in ECDSA-signed X.509 certificates

I wonder if there is a standard way of encoding the ECDSA-signature in the signature field of an X.509 certificate. As far as I understand, the signature is a tuple of two integers r and s. If the ...
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2answers
526 views

At which offset is the public key in an DER encoded certificate chain?

I have the following bytes array storing a certificate chain (DER encoded): ...
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0answers
38 views

Why Signature Hash Algo SHA-1 still uses for X509 by GeoTrust [duplicate]

Google has successfully shattered SHA-1 and still I found that SHA-1 digest algorithm is used for signing the hash. Even Google Chrome is accepting this kind of certificate without any kind of warning....
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2answers
650 views

Correct settings to generate private intermediate CA

I am using 'xca' in Linux to set up a private CA. xca only includes templates for the Root CA and End-User CA, no intermediates. What are the correct settings (fields and flags) for an intermediate (...
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2answers
97 views

How to get public prime from DHE from TLS v1 DHE-RSA x.509 certificate?

I can view the certificate using openssl s_client -showcerts -connect www.masaood.com:443 </dev/null I can view the public key of a RSA, but cannot find any information for DHE: openssl ...
3
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1answer
280 views

X.509 Why is the signature algorithm added twice in the Attribute Certificate?

As I read some parts of the X.509 specification I found the signature added twice - first in the AttributeCertificate as signatureAlgorithm and second in the AttributeCertificateInfo as signature. ...
2
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2answers
118 views

Verify that a second TLS connection comes from the same client

I would like to implement kind of a trust-on-first-use (TOFU) scheme with TLS: A client creates a key and a self-signed certificate. The client connects to the server with this certificate. The ...
6
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2answers
3k views

WPA2 Enterprise EAP-TLS Key Exchange

I'm in the process of implementing 802.1x WPA2 Enterprise Authentication using FreeRadius and EAP-TLS (Mutual TLS Cert Based Auth). I am keen to understand how to actual protocols work together and ...
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2answers
2k views

X.509 certificate renew vs. rekey

What is the difference from CA perspective between renewal and rekeying of the certificate previously issued by this CA?
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2answers
902 views

RSA or ECDHE for key establishment?

Recently, i have been looking at PKI and certificates, and TLS 1.2 as part of my study of cryptography. I have the understanding that the public key included in the certificate of a website is the key ...
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3answers
2k views

RSA or ECDHE for x.509 certificates-what does each do?

I am relatively new to x.509 certificates, but recently i have been looking at the https connection padlock at the top of the screen. On certain websites, clicking on the pad informs me that the site ...
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4answers
25k views

Missing X509 extensions with an openssl-generated certificate

My goal is to create a certificate with opensslsimilar to this one generated with cfssl Certificate: Data: Version: 3 (0x2) Serial Number: 60:44:dc:0d:80:f4:54:55:e8:...
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7answers
7k views

Could governments and banks become CAs?

When you apply for a passport, driver's license, home mortgage, bank account, credit card, etc., the issuing organization must verify your identity. In the course of doing so, would it be feasible for ...
3
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1answer
2k views

How are ECDSA signatures computed for X509 Certificates?

I am trying to verify a certificate signature on my own. To do this, I created a self-signed certificate using OpenSSL with the two following command lines: openssl ecparam -name secp256k1 -genkey -...
2
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1answer
2k views

Using short hostname in X509 certificates

We are using an internal Certificate Authority for our company. We noticed that it is possible to add as subjectAltName the hostname without the domain. We are using example.org for internal servers ...
4
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1answer
9k views

OpenSSL Verify: Difference Between “unable to get issuer certificate” and “unable to get local issuer certificate”

From the man pages: 2 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT: unable to get issuer certificate the issuer certificate of a looked up certificate could not be found. This normally means the ...
4
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1answer
406 views

How to restrict a X509 certificate to be used only for a web server

I would like to restrict the X509 certificate for a site to be used strictly for a web service, as opposed to code signing or certificate signing. Which basicConstraints and keyUsage usage attributes ...
6
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2answers
17k views

Does openssl refuse self signed certificates without basic constraints?

I have two extremely similar self signed certificates, generated via two different methods. To test them I have: Added an entry in my hosts file for local.mydomain.com Set up an nginx server to ...
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0answers
194 views

Can I revoke a CRL-signing certificate by using split CRLs?

I'm setting up an X.509 certificate authority that will issue only three types of certificate: Subordinate CA certificates, CRL-signing certificates, and OCSP responder certificates I'm interested ...
0
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2answers
7k views

What's the difference between “Public Key Algorithm” and “Signature Algorithm” in OpenSSL output?

If the output is:- ➜ $?=0 % openssl x509 -noout -in ./cert -text | grep Algo Signature Algorithm: sha256WithRSAEncryption Public Key Algorithm: id-ecPublicKey Signature ...
0
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1answer
190 views

Certificate chain mantainance [closed]

According to standard rfc5280 , when user wants to validate a certificate, one step is to build a certificate chain, then check whether it is complete. I understand the idea to make a list to ...
2
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2answers
6k views

One certificate for both client and server authentication

Is there any reason why I shouldn't issue end entity certificate with both TLS Web Server Authentication and TLS Web Client Authentication? What should happen if the client certificate which should ...
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1answer
2k views

Certificate verification worries

I am having trouble getting a SSL connection to work. I did a lot of research on the web, but i am still missing some understanding it seems. I hope you can help me. I generate a development ...
0
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1answer
509 views

Testing Digital signature on an incoming request via Apache

I am creating an API endpoint that receives payload from a third party. The third party is signing the request with there X509 Certificate(Private Key). I have been provided with their Public ...
2
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1answer
1k views

How issuer's certificate is found to verify a given certificate?

I'm trying to understand how digital signing using x509 certificates works. I read a few articles and related answers on the web, but still there are a few questions left to confirm my understanding: ...
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3answers
1k views

Reason for Subject name in an X.509 Certificate

For my studies, I'd like to dive a bit deeper into PKI and X.509. Talking about certificates, one always gets the following sentence: "Digital certificates map public keys to entities" This means, ...
3
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2answers
4k views

Where is the version number in an x509 version 1 certificate?

I'm parsing x509, versions 1 and 3. I found the version field in the v3 cert, but I have two v1 certs (one from my organization, one I generated via OpenSSL) and in both of these the first non-...
0
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2answers
103 views

Certificate Validation [duplicate]

Sorry if this has been asked before, but I couldn't find an answer anywhere. Maybe I overlooked something, but I just can't wrap my head around how certificate validation works. This post details how ...
12
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2answers
251 views

Who was in the first set of CAs

I am currently digging into the history of SSL/TLS. I found that netscape introduced SSL around 1994/1995. They obviously decided to go with a X.509 PKI to mitigate MitM attacks. I, however, could not ...
2
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0answers
63 views

Is there an imbalance of issuer and responders in OCSP verification?

I'm trying out OCSP verification, and I'm not sure I'm following all that's going on. The requester can send 1-N certificate IDs, each has issuer hashes/serial no. The responder generates the counter-...
12
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2answers
3k views

How to properly create and use cross-signed CAs and certificates

I'm trying to create an environment with cross-signed CAs, and verify a certificate issued against one of the CAs, all using openssl. The best I got so far is getting openssl into an endless loop ...
5
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2answers
8k views

How TLS certificate chain is verified

Assume the verification of a TLS certificate chain. Suppose the chain has certificates A-B-C-D where D is the root certificate and A is signed by B, B by C, C by D. Suppose the intermediate ...
4
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1answer
105 views

Establishing trust between a device and a developer, TLS signal vs X.509, GnuPG (or both)

Let's say you wanted to implement a "secure sideloading" mechanism for your embedded device so that the device could establish trust with authorized 3rd party developers. Developers would have local ...
5
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1answer
640 views

Why are there leading 0x00 bytes in the subjectPublicKey field of a DER X.509 cert?

For a simple example, I'm using a 512-bit RSA cert to illustrate my question. The cert can be found in both DER and PEM form here. I've been going through the certificate using this ASN.1 decoder (the ...

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