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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26
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2answers
4k views

If you revoke a certificate authority's certificate, do all of the certificates it issued become invalid as well?

If you revoke a certificate authority's certificate, do all of the certificates it issued become invalid as well? What about for certificates issued by an authority beneath it? For example, if root ...
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4answers
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Can a revoked certificate be re-instated?

If a certificate is revoked, can it be re-instated, or is the only option to generate a new one?
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3answers
162 views

Sharing an expired certificate?

Today one of our certificates expired and I needed to order a new one. When collecting all the data needed to create a new one, I got the idea that all needed information is already contained in the ...
0
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1answer
48 views

Is it possible to fabricate x.509 certificate with varying issuer and subject fields?

I'm testing a service that might not do a proper checks for the certificate chain but instead it checks issuer and subject fields only. I would need to create a (self signed?) certificate with ...
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3answers
25k views

What is the use of cross signing certificates in X.509?

In X.509 architecture what are the uses of cross signing certificates from other hierarchy? Does it just expand trust? So from the answer I am assuming that if CA3 is cross signed by CA2 (from ...
0
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1answer
68 views

Where precisely are client X509 certificates stored?

Apologies for what might seem like a naive question, but there is a detail to PKI architecture between clients and servers, the answer to which I have so far not been able to come across no matter ...
3
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1answer
212 views

Using NameConstrains in a CA certificate

I am trying to do something similar to what has been pointed out in this nice answer by Jonathon Reinhart. I have a CA certificate with Name Constrains (RFC): Permitted [1]Subtrees (0..0): ...
0
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1answer
74 views

Digital signature using only x509 certificate

Is it possible to digitally sign a document only with a x509 certificate (ie public key)? We received a question from one customer saying that they wanted to sign a document using only a certificate. ...
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2answers
756 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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5answers
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A standard way to manually add a digital signature to a pdf file?

I've created a few certificates to use myself, but I find myself stumped when it comes to creating a certificate which contains a digital signature. First, how would I go about creating a standard ...
0
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3answers
99 views

How does the browser decide to accept a self-signed certificate?

As far as I know, with OpenSSL, you can self-sign your website's certificate. This means that the browsers that will connect your server are supposed to be willing to accept a self-signed certificate ...
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1answer
50 views

Attribute certificate to model subject-object-action for access control

I am using Attribute Certificate (along with X509 PKC) for access control. What I really want to model is an access control semantic where a subject has a privilege to perform certain action on ...
1
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1answer
176 views

OPC-UA Certificate Handling

I am currently developing and extending an OPCUA-Server based on "node-opcua". The next steps would require to add certificate handling and that's also the point that makes me the most problems. My ...
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0answers
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x.509 certificate chain verification in Linux kernel prior to 4.12

I am trying to use certificate chain verification in Linux kernel. The purpose is to use IMA/EVM with public keys that are included in x.509 certificates signed by an own root CA. For this purpose I ...
5
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4answers
16k 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:...
1
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1answer
56 views

Feedback for self-signed certificates setup for custom product auth?

HW (linux) <---Eth---> Official PC (win,mac,linux) | | ----> Man-in-the-middle eavesdrop I'm looking to prevent an unauthorized party inside the ...
5
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4answers
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IP address in SubjectAltName

Is it allowed to specify IP as DNS name for SAN certificate ?
0
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0answers
53 views

percentage of X.509 certs using rsaEncryption as publicKey algorithm

Quoting 2017_TLS_Telemetry_Report.pdf: Not surprisingly, 2048-bit keys now protect 90% of the world’s TLS hosts. The use of 4096-bit keys have quadrupled, as a share of hosts, but we expect it to ...
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0answers
17 views

What would happen to the connection when certificate expires? [duplicate]

We are using X509 certificate to connect between on-premise devices to the cloud services (Device provisioning service from Azure) The expiry date of the certificate is 3 years from now. Once the ...
2
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0answers
47 views

RFC 5280 compliant certificate with x509 extensions

First time posting here, be gentle. Situation: I have a requirement, to link our printer/scanner to our Azure AD (so that it can lookup users etc.). I have enabled Azure AD Domain Services with LDAP ...
10
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1answer
5k views

The difference between Subject Key Identifier and sha1Fingerprint in X509 Certificates

I have some SW that extracts certificates data and the SW utilizes OpenSSL. I am confused what is the difference between the subjectKeyIdentifier and the sha1Fingerprint. Both are hash values. My ...
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0answers
134 views

Creating X509 certificate in C using post-quantum public key algorithm?

I'm trying to implement a self signed x509 certificate that uses a post-quantum (PQ) public key algorithm as the public key algorithm. I looked at the openssl library in c, and the way it's done using ...
3
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1answer
850 views

Does TrustManager PKIX (or RFC 3280/X.509) really check the expiration date of a client's certificate?

It was noticed that the default java implementation of TrustManagerFactory for PKIX trust manager algorithm (X509ExtendedTrustManager) doesn't really check the expiration date of a client's ...
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2answers
226 views

Convert CSR to self-signed x509 Certificate

Is it possible to receive a certificate request (CSR) and convert it to a self-signed X509 Certificate without having access to the private key that signed the CSR? I want to do the following: receive ...
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0answers
205 views

Converting a raw EC public key into EVP_PKEY using openssl

I am trying to convert a raw EC key and EVP_PKEY structure. The process seems straightforward but am running into issues. Here is the code I am using -- unsigned char tmpPubKey[] = { 0x04, ...
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2answers
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What's the difference between X.509 and PKCS#7 Certificate?

Am I correct calling file with .p7b file extension saved as 'Cryptographic Message Syntax Standard - PKCS#7 Certificates (.P7B)' in Windows - a 'PKCS#7 certificate'? Or is it better called 'X.509 ...
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1answer
200 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 ...
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1answer
46 views

Server to Server Communication RSA or x509 Certificate

I want to build Server (My) to Server (Other Client parties) web service and I want to add security layer for client verification. Do I need to force clients to create x509 Certificates or RSA key ...
73
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2answers
91k views

What is the difference between serial number and thumbprint?

I have problems to understand what is the difference between the serial number of a certificate and its SHA1 hash. The MSDN says: Serial number A number that uniquely identifies the ...
4
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1answer
118 views

Should TLS clients put a limit on certificate chain depth?

Specifcally, when configuring nginx to validate proxy target SSL certificates (which it mystifyingly does not do by default), a maximum cert chain depth must be specified in the proxy_ssl_verify_depth ...
0
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1answer
772 views

X509 “Serial Number of certificate” vs serial number attribute in Issuer and Subject?

Is the serial number attribute of an X509 certificate Issuer or Subject, as defined in RFC5280, required to be the same as the Serial Number of the issuing or subject certificate? It seems quite ...
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0answers
52 views

Examples for use of encipheronly and decipheronly bits in the keyUsage field of a X.509 certificate

I am requesting for real life example of using the encipheronly or decipheronly bits together with the keyAgreement bit in the keyUsage field of a X.509 certificate. The RFC 5280 specifies about these ...
2
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1answer
61 views

How common is it for CAs to issue end entity certificates with Extended Key Usage marked as critical?

Does anyone know whether it is common for CAs to issue end entity certificates, which can be used as client certs (possibly among other purposes), with the Extended Key Usage (EKU) extension marked as ...
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2answers
251 views

Is SubjectAlternativeName in X.509 always used for DNS Names?

X.509 certificates as of RFC5280 offer the two fields "Subject" and "Subject Alternative Name" that can be used to describe the Subject of the certificate (e.g. a Domain example.com). Section 4.2.1.6 ...
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2answers
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Creating root CA to issue certificates programmatically

I have to generate a self signed root CA and use it to issue to certificates programmatically. I am new to security and certificates and I think I am missing some pieces required to make the whole ...
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1answer
2k views

When can I commit an OpenSSL Certificate (.pem) to source control?

That is to say, in what cases does it make sense to commit .cer files, or a stack of .cer files in a .pem, to internal source control like SVN or Git? If it's just a list of signed public keys, I ...
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0answers
92 views

X.509 Certitificate Authentication between Client / Server (REST Implementation Model)

Can you please list of advantages /disadvantages on X509 Certificate based authentication instead of traditional username/password model ? Architecture Scenario : Lets suppose i have Client ...
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2answers
280 views

What is being verified in OpenSSL's SSL_get_verify_result

In OpenSSL the following function is used to verify certs. SSL_get_verify_result I looked at the manual here. But it does not detail what is being verified. Can you clarify to me what does this ...
7
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2answers
2k views

Custom data in SSL certificate

I am looking for a way to add extra, custom data in a SSL server certificate issued by a standard CA. Is this possible? I want to get a SSL server certificate issued by a standard CA, so that it'll ...
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0answers
49 views

What is this error for rootca for wrong system time?

Getting this error for openssl smime verify 140392937076368:error:21075075:PKCS7 routines:PKCS7_verify:certificate verify error:pk7_smime.c:342:Verify error:certificate is not yet valid After ...
0
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1answer
79 views

Can rootca validity start date be lower than current date?

What will happen if we create rootca X509 certificate with validity date lower than current date? Will date of creation taken into account while cms_verify? What will happen if we change the system ...
0
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1answer
66 views

Is this CA store related to Ubuntu or OpenSSL

I am checking TLS certificates chain validity against CA sore in this path: etc/ssl/certs/ca-certificates.crt I use Ubuntu 18.04 and OpenSSL 1.1.0g. I need to know whether this CAs store is from ...
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2answers
12k 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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1answer
1k 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 -...
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2answers
4k views

Why one should prefer EST protocol instead of SCEP?

For many years SCEP was a simple and widely used protocol for obtaining X.509 certificates. However, not too so long ago another protocol called EST (RFC 7030) was developed. What are the main ...
3
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1answer
316 views

How can I use X.509 cross signing to replace a CA?

I have a self-signed CA that I want to rotate the key for. I want to use cross-signing to facilitate this, with gradual replacement of the certificate on the clients so they can still communicate. I'...
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0answers
61 views

Is there a compiled list of TEE (Trusted Execution Environment) manufacturer/CA certificates?

I may be misunderstanding TEEs (I just learned about them from an HN post), but I have question regarding the features that seem to allow what seems to be the perfect form of DRM (to my maybe limited ...
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 ...
1
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1answer
71 views

Self-signed CA certificates - Can we throw away the private keys

I'm rather confused about self-signed certificates. I would be grateful if anyone can clear up my confusion. I'm working with Amazon AWS IoT, and in order to create our own certificates on a device ...
1
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1answer
361 views

Understanding Microsoft list of disallowed certificates

Microsoft publishes their untrusted certificates as disallowedcerts.stl Warning: direct download. It is ASN.1 encoded. After decoding it there is a list of sequences like so: SEQUENCE { ...