Certificate Revocation is a process through which we make sure that those certificates that are not considered valid are not used by relying parties.

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What bits of data is revoked in a CRL? Is it the hash(CSR) or hash(CSR + PKI signature)

My understanding is that a CSR contains the public key from the client, and the response is a signed version of that CSR, with certain attributes (EKU, expiration) and other attributes the CA decides ...
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41 views

Can revoked certificates be “lost” if the base CRL is updated before expiration?

Assumption Suppose I have a CA that issues a base and a Freshest CRL. I also understand the Freshest CRL to be a Delta of revoked certs in the base. I also understand that clients should pull the ...
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1answer
35 views

Mail Signing Certificate – What are the impacts when revocated?

Suppose I open a signed mail on 1st January 2000, signature is OK. What about this two cases : 1) If next CRL is to be published one week later, I found it strange that it is “probably” valid until ...
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56 views

Check signature when next CRL will be published after end of validity of certificate

My situation looks like this: I have to verify signature on document. For this I will wait when next CRL will be published to check that involved certificate was not revocated. But what if ...
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2answers
78 views

SHA1 - S/MIME and CRL validity after deprecation?

In an internal PKI using SHA1 for hashing, will S/MIME signature and CRL/ARL signature be considered invalid in the next few years (SHA1 Deprecation) ? End certificates can be revoked, CA ...
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25 views

Can I store a GPG revoke certificate online?

It's clearly a good idea to store the revocation certificate in a way which is both secure and reliable. Cloud-based storage services are great for reliability, but of course they lack of security. ...
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2answers
161 views

Why Google Chrome complains about mozilla.org identity?

On a "brand new" (but fully updated) Windows XP installation (an Asus EeePC that I restored to factory setting and than updated with all Microsoft's upgrades) I installed a few days ago Google Chrome. ...
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600 views

Is publishing CRLs over HTTP a potential vulnerability?

I noticed that at least one major CA (Comodo) publishes their CRL over HTTP rather than HTTPS. This seems to me to be somewhat of a vulnerability, as an attacker could hijack the HTTP connection that ...
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28 views

What are valid OpenPGP revocation signature types?

I'm working on an analysis of the full OpenPGP keyring (ca. 3.8 million keys). I imported all keys to a local instance of hockeypuck (keyserver implemented in go). Hockeypuck uses a PostgreSQL ...
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79 views

PKI expired and renewed, do my correspondents have to do anything?

My PKI certificate (Digital ID for email from Symantec, issuer is "VeriSign Client External Certification Authority - G3") expired after 1 year and so I have renewed it. Do the people I correspond ...
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1answer
556 views

When does iOS check validity of enterprise certificates?

Here is an article that should give a little more context (and see my comment on it, same username, for additional info). iOS developers are able to distribute apps outside of the App Store using an ...
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2answers
881 views

Website Certificate Revocation check - Big deal? [duplicate]

As I was about to make payment for my flight ticket, I noticed something strange with the British Airways website's SSL cert. My browser (Google Chrome) was unable to check whether the certificate has ...
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4 views

Do any certificate revocation schemes revoke certificates issued before a certain date?

In the case of a large number of certificates needing to be revoked, the certificate revocation list may get quite long. This could be difficult to distribute over low bandwidth connections or to ...
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2answers
1k views

Trying to get rid of hackers who have access to all my devices [closed]

What is the best way to go about getting rid of hackers that have gained access to all my personal computers, (both old and recently purchased) phones, and even random computers I use to simply get ...
2
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2answers
87 views

Should expired compromised certificates be taken care of if the time is always correct?

I am trying to set up a CA for my company, and issuing every employee a digital certificate and a private key. I am worrying about revocation and expiration. In my case, the root certificate of CA is ...
0
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1answer
56 views

Keep OpenPGP revocation certificate in safe place?

Do I have to keep the revocation certificate of my OpenPGP key in a safe place or may I place it in e.g. Dropbox to have it ready on all my machines? I know that, if compromised, the certificate can ...
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426 views

How can we revoke all ssl certificates issued for our domain?

After having the hostmaster@domain.com email compromised, we found that someone issued a Domain Validated SSL certificate for our domain. Now we want to have all such certificates revoked. Is there ...
7
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1answer
111 views

What considerations should apply for self service Renewing, Revoking, or Unrevoking a certificate?

I need to design a self service portal for renewing, revoking, and unrevoking a certificate and have come up with the following rules*: Renewal Certificates have a short term validity and need to ...
2
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2answers
83 views

What's the mitigation strategy for when a CA's private key is stolen?

I'm new to SSL/TSL and was wondering if you could walk me through the following scenario. Scenario Let's say I am one of a thousand websites that has a certificate signed by some certificate ...
2
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1answer
94 views

Is there any mechanism to audit which signed certificates are unrevoked?

We are currently using EasyRSA and OpenSSL to manage our user VPN certificates for OpenVPN. The process we have in place currently is: User generates a CSR on their laptop and sends it to us to sign ...
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4answers
97 views

Temporarily suspending a Certificate Authority's Certiticate

The PKI RFC talks about revoking or suspending certificates. It also talks about revoking CA certs. However, I could not find anything about whether a CA or a Sub CA's certificates can be revoked or ...
4
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3answers
809 views

From a trust perspective, is renewing a CA certificate the same as trusting a sub-CA?

I'm trying to understand the validation logic that would occur in the following hypothetical scenario An unpatched XP user who trusts a list of root CAs. Those CAs in particular have been renewed ...
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5answers
2k views

Why are certificates limited in time?

If a certificate has a limited duration of, say 5 years, but it gets somehow compromised after 2 years, waiting the 3 remaining years for it to get invalid is not a real solution to the breach ...
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1answer
75 views

How does checking CRLs make sites less safe?

With the frantic certificate upheaval resulting from the Heartbleed fiasco [drink!], there has been lots of talk regarding certificate revocation, and in particular the policy of certificate ...
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2answers
150 views

A doubt in certificate chain validation and revocation checking

So when i do a tls handshake with the server, it responds with a cert chain which the browser verifies and which ends at a trusted root CA. In this the browser checks if the cert presented by the ...
7
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1answer
293 views

How can I verify if a website revoked its old SSL certificate keys? [duplicate]

Through reading from multiple sources and watching Security Now's How the Heartbleeds, I have come to the understanding that the following procedure is recommended to be safe from the Heartbleed ...
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3answers
335 views

How are CRLsets more secure?

Google Chrome doesn't do typical CRL/OSCP checks, instead it depends on CRLsets. In simple terms, Google scoops up the CRLs from most CAs, trims them down and delivers the CRLset to the browser via ...
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2answers
609 views

SSL cert minimize downtime key rotation strategy

As you already know, due to the heartbleed bug, we need to perform re-keying on our web servers (>10), before I do that, I want to check if my proposed strategy is a proper way or not a. Generate a ...
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2answers
2k views

How to configure Browser to detect revoked certificates?

In the context of the Heartbleed bug I would like to make sure that I can detect if someone tries to do a MITM attack with a stolen certificate, which since has been revoked. The problem is that ...
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1answer
145 views

Is long-term validity definitively corrupted upon TSA certificate revocation?

Suppose a document that was signed with a long-term signature (e.g. CAdES-A): D S T1 (D - document, S - signature, T1 - time-stamp created using a time-stamping certificate C1). If C1 appears in the ...
3
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1answer
191 views

How to handle CRLs correctly in long-term electronic signatures?

What is a recommended way of handling CRLs in long-term electronic signatures (specifically the CAdES-A)? The problem I see is in that CRLs are not protected against modification (they are plain ...
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1answer
95 views

Good reason to continue using fraudulent certificate?

A relative of mine used a favorites link to login to yahoo. The favorite link is https://de.mg40.mail.yahoo.com/neo/launch? However, this link uses a fraudulent certificate. Visiting the Yahoo ...
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1answer
82 views

Is a PGP revocation certificate sensitive?

In relation to an openpgp key on a smartcard: Besides revoking the key, is there anything else it can be (ab)used for? Can I just ensure it's reliably stored but not worry about it's confidentiality? ...
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30 views

Specify port for cRLDistributionPoint?

cRLDistributionPoints is OID 2.5.29.31. Here's what one looks like under Gutmann's dumpasn1: SEQUENCE { OBJECT IDENTIFIER cRLDistributionPoints (2 5 29 31) OCTET STRING, encapsulates { ...
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0answers
54 views

Cetificate Pinning. How do we handle the situation where a website is visited for the first time?

What I essentially mean to ask is, how is the scenario where a user who visits a website for the first time (the certificate for the website is not pinned in the browser) handled ? Additionally how is ...
3
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3answers
159 views

The best way to change my pgp key

I would like to change my pgp key because I have the same one 2 years ago. But, I want to warn my freinds that the owner of the old key and the owner of the new one is the same person (me). hwat is ...
4
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3answers
451 views

Certificate Transparency

From what I read here, if the intermediate CA has been compromised, a fake cert can be issued and the privacy of the end-users could be compromised as well. In order to remediate this situation, ...
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1answer
143 views

Should all Server Certificates from one CA have the same CRL

I am setting up my own PKI, and I came across a question to which I couldn't find an answer. I want to specify CRLDistributionPoints in my server certificates but I am curious whether to use the same ...
3
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1answer
112 views

In theory, can x509 certificates use Accumulator-based revocation schemes? How do these schemes work?

On page 3 of this U-Prove document regarding toke revocation, the author says the benefit of Accumulator-based revocation schemes is A cryptographic accumulator allows the aggregation of a large ...
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3answers
2k views

Revoke a certificate without index.txt

I generate self-signed client certificates for a little Apache server hosted under my stairs. The script below was hacked together for this purpose - note it uses the 'mini-CA' x509 method, therefore ...
2
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1answer
428 views

ISO 27001 failure to comply

Say a small company just earned an ISO 27001 accreditation. What happens if during one of the audits it is found that the company didn't follow the ISMS? Is there a certain warning process that ...
6
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3answers
427 views

Why does OpenSSL need the private key to revoke a certificate?

openssl ca -revoke signed/0A.pem -config caconfig.cnf What does this do which requires the CA's private key? Does it do anything except updating index.txt?
8
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1answer
672 views

Force a subordinate CA cert to be signed to include a the CRL distribution point extension?

How can I attach a crlDistributionPoints parameter when signing a CSR I've generated as follows: openssl req -new -key /root/ca/private/private.key -out /root/public.csr I usually sign with: ...
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3answers
2k views

Why are Certificate Revocation List periodically renewed?

While studying a security course I have been asked this very question: Why are CRL periodically renewed, even if there are no new revoked certificates to add to the list? Honestly I can't find the ...
5
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3answers
839 views

Why do we allow SSL certificates to be replaced before their expiry date, without revokation of others?

Imagine a situation where a rogue CA creates a certificate for your site. Since the user's browser trusts the CA, it will accept the certificate without any fuss. However, the site's real certificate ...
2
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1answer
2k views

How does an offline CA revoke certificates?

If an RSA private key of a root CA is stored offline, how does it revoke certificates it signs? From looking at OpenSSL config the default_crl_days option seems to indicate that a CRL must be ...
4
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1answer
160 views

User Groups (Circles) Inside a Web of Trust

Assume I have a universe of U users. Every user has his private key. I want to build user groups by adding a company sub key to his key set. Now users can sign his company sub key with there company ...
5
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1answer
716 views

Is there any malicious reason to block CRLs?

I've noticed that in order to 'illegally' crack certain applications, it is necessary to patch the host file to stop communication with the activation servers. I've found that with several ...
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3answers
301 views

What is a reasonable expiry for user authentication certificates?

This question is about a nearly decentralized P2P system with a centralized certificate authority where users can authenticate and receive a certificate on their public key and then can authenticate ...
0
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1answer
338 views

Does S/MIME provide means to propagate a certificate's revocation?

Can a revocation certificate for an old X.509 certificate be attached to an email in addition to a replacement certificate in such a way that the client user does not have to manually intervene? Or ...