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2

The risk of using a shifty-looking CA is not in the certificate enrollment process: as long as you generate the key pair yourself and send only the certificate request to the CA (which contains only the public key) and receive the raw certificate in return (not a PKCS#12/PFX archive), then your private key is yours and yours only. The risk, though, is in ...


4

There is no risk of compromising the private key, because you send only the CSR which contains the public, but not the private key. But, using a CA is in effect a trust delegation, e.g. people trust your certificate because they (or the browser) trusts the CA which signed the certificate. Once they notice, that the CA is no longer trustworthy (like DigiNotar ...


-2

Yes, a major one. They will have the private key (because they got it, then passed to you) and can thereby impersonate your website at will.


0

CMP is a generic protocol which aims at covering most (if not all) network exchanges involving a Certificate Authority; e.g. it includes messages for a CA who wants to announce that it has a new key pair. The protocol is rather complex, and has been around for quite some time (first published version is from 1999). SCEP is a specialized protocol which has a ...


0

Php can determine what is browsers is running and other system detail by running a bit of code. Try to identify the MAC address of each computer by php, so only known computers can gain access.


2

What you are describing is actually your own, reduced auto-update feature, limited to updating what amounts to a "trust store" for certificates. The bad thing about it is that it works outside of the normal app update mechanism, without much possible user intervention, so the user will get the updates whether he wants them or not. The good thing about it ...


0

There's a very interesting use case in this other answer, using client-side certificates: Why would the BBC web site always ask for a personal certificate, and how do I avoid giving it away? Another quick-and-dirty option might be implementing a VPN and shifting the domain of the problem from PHP to system administration. This might prove useful if, in the ...


0

thats long story, can't comment so leave as link here Using SSL Client Certificates with PHP also you may take look at apache SSLRequire Directive may a bit sorter story also PHP OpenSSL module php.net/openssl plenty of stuff around that question


0

You could setup SSL and create your own certificate. I believe there is an option to create something like client approved certificates. That means that you need to install the client part of the certificate on the client (the browser). If the client doesn't have this installed, it won't work. To be honest - this is something that I read about last week, ...


0

Limiting access for the web browser (user-agent) is something that is very easy to manipulate using a tool like Tamper data. You can change the header to make it look like the request is coming from any browser you want. If you want to make sure they can only access the website from the office (if this is one location) you could restrict access based on IP ...


0

If you are using PHP web application, you can use this function to check client browser.


0

On the server, it's easy to check the headers of each HTTP request (the User-Agent header, in your case) and redirect to a landing page that explains why the browser can't be used, and which browsers are supported. You'll need to install a form of authentication to validate requests originating from unauthorized clients. Installing an X.509 certificate on ...


33

You shouldn't really be worrying about this, the certificate contains only your public key, which is supposed to be public anyway. The only issue is the privacy concern of giving away the information in your certificate to any site that asks for it. Summary of the issue: The BBC weather page has a request to http://www.live.bbc.co.uk. HTTPS Everywhere is ...


0

Can you explain exactly how the other browsers fall back? I've seen the following scenarios with servers and middleboxes: try to connect with TLS 1.0 or higher, peer responds with SSLv3 and thus the connection continues with SSLv3. This usually succeeds. try to connect with TLS 1.0 or higher, peer closes connection and browser tries again with lower TLS ...


5

I find the question useful, because it is actually hard to find out if a certificate got revoked the right way. If you know who issued the original certificate you can download the CRLs (which contains only the serial numbers and the date of revocation, not the revoked certificate itself). If not you are out of luck. If you know the serial number of the ...


5

Oooh, that's a tricky one. Theoretically, the nextUpdate field is meant to be a (future) date at which a new, updated version of the CRL should be made available. The idea is that if you have a cached CRL, then there is no point trying to download a new one before that date. In "true X.509" each relying party (a "relying party" is "some system which tries ...


0

Turns out the problem had nothing to do with the certificate and everything to do with the fact that the client was coming in over the VPN. When the client was physically on the network, everything worked fine. I ended up having to change the MTU on the ubuntu server and everything worked fine.


1

Let's assume, for an instant, that you really need to "re-key your Web servers" because of the heartbleed bug (if there is such a need, then you quite logically also need to do it for every other similar vulnerability which shows up, hence several times per year, and you must also do it for vulnerabilities which will show up, so, by that reasoning, your ...


1

You assume incorrectly: a cert does not have to be revoked when re-issued. It is typically a different process altogether. This means that you should add a last step to your plan: revoke the old certificate once you are done with installing the new one. Clients will not cache your certificate. In fact, they cannot keep a cached copy since it is your server ...


1

File name "extensions" are immaterial. There is no real standard for these few letters, only loosely maintained traditions. The PKCS#7 standard (now called CMS) describes how to encode and decode signed and/or encrypted and/or authenticated "messages" into sequences of bytes. How these sequences of bytes are stored or exchanged is completely out of scope; in ...


1

Good Question. TACK is a "dynamic pinning" solution to the broken Certificate Authority model we all depend on today. A competitor is Google's Certificate Transparency (CT). Status of TACK is No browsers currently support it. There are no browser extensions to enable it. The last posting from the developers (January, 2014) is that it is entirely up ...


5

Normal, serious root CA are offline. They are hosted on machines which are never connected to any kind of network. This tends to make them immune to remote attacks, and that's the point. Technically, the reasons which have warranted key renewal ("the bug was there, so there might have been a compromise that we don't know of") are still valid: it would be ...


1

There are variety of ways to look into your question . Apply the patch for the heartbleed bug and use openssl Use Options to bypass heartbleed or versions of openssl that dont have heartbleed problem. more here Use some other Crypto Library (does not gaurentee it does not bleed later ) Basically, there is no fool proof way or ideal way to distribute keys ...


5

Yes. Most private keys have an easily identifiable format. If its say an RSA private key generated with openssl, they have a specific format e.g., will always start with the same three bytes depending on key size: 30 82 01 (for 768 bit key or MIIB in base64) 30 82 02 (for 1024 bit key or MIIC in base64), 30 82 04 (for 2048 bit key or MIIE in base64), 30 ...


0

Upon SSL establishment to the remote server, the certificate chain is retrieved to ensure the trust of the host, if any certificate in the chain is revoked, the chain will be broken and you will recieve a certificate error(untrusted site) upon entering. This is why we use external root CA's like godaddy and such, to confirm the identity of the remote ...


0

In case of HTTPS protocol, Common Name can also be used by some of the client applications for verification of the server's identity. The RFC 2818 says the following about the server's identity: If a subjectAltName extension of type dNSName is present, that MUST be used as the identity. Otherwise, the (most specific) Common Name field in the Subject ...


3

As far as X.509 is concerned, the Common Name is not mandatory. However, a number of systems will use the CN for display purposes, e.g. most "certificate manager" GUI in Windows. Therefore, it is recommended, if only for ease of sysadmin tasks, to include reasonably precise CN in certificates. If you want to, from an application, pinpoint a specific ...


0

To keep it short and simple. Is there a need for external trust? If what you wish to protect is for internal use only, there is no need for an external CA like GoDaddy or Symantec. With a deployment service you can provision the affected nodes with the CA cert used to create trust in the 'network'


1

A certificate is basically a binding between an identity and a public key, but there are details: The notion of "identity" which is most adequate for your situation is not necessarily the same as the notion of identity for a SSL server certificate (i.e. a server DNS name...). The lifecycle of the private key matters: who generates it, where it is stored, ...


-1

Take my chrome as an example, in the url, there's a green lock: when you click the green lock, you will see: when click "certificate information", you will see the certificate, click details, you can see: the "not valid before" is when the certificate create. Actually in this case, since Yahoo is affected, so its certificate is issued just today. ...


0

Basically, any CA does exactly what it wishes to do. However, OS and browser vendors won't accept just any CA as a "trusted root". E.g. Microsoft runs a root certificate program which defines the contractual conditions that a CA must fulfil in order to get its root CA public key included in the "trusted store" of all Windows systems. These conditions include ...


3

Heartbleed has pretty little relation with certificates. The only link is that a potential consequence of a successfully exploited heartbleed is a reveal of the SSL server private key. Therefore you might want to go to full paranoia mode and consider that any private key which was used in a vulnerable server is toast and must be replaced. This is quite ...


0

According to the wikipedia page and specifications a certificate does not hold information regarding the creation date.


0

To expand on Stefan's answer: I would also ensure that the certificate used for signing is different than the one used for encryption, as well as different from the one the TLS (I hope you aren't still using SSL) is using to secure the communications channel. In other words... A unique certificate for each thing.


2

I think I understand the question as: If a servers' private keys have been compromised, won't a MITM attack be possible even if the heartbleed vulnerability has been patched? (given that not all browsers mandate Certificate Revocation List (CRL) checking?) And I believe the answer is indeed yes. Patching against the heartbleed vulnerability ...


0

It is not specified that the certificates for two idps must be unique. As far as I know you dont even have to have a certificate. But its recommended.


2

If you're trying to protect data-in-transit between two servers, please just use SSL/TLS certificates instead of rolling a new encryption scheme. Note that SSL/TLS technically uses symmetric encryption as well, but the shared session keys are encrypted with asymmetric keys during the initial exchange (hence the need for certificates). One of the huge ...


2

When AD Certificate Services starts up, it insists on validating its own certificate (the subordinate CA certificate). This entails verifying that the CA certificate has not been revoked, by obtaining the CRL referenced from the CRL Distribution Points extension found in that certificate. If the CRL have been moved, and not up-to-date CRL can be found at ...


8

Depending on how the CA does things, it may or may not have a copy of your private key. Usually it doesn't. The normal method is that you generate your private/public key pair on your own machine, then send the public key to the CA as part of a certificate request. The CA assembles and signs the certificate, and sends it back to you. Your private key never ...


1

When the CA signs the locally generated keypair, the private key is never seen by the CA server. If you use IE in a corporate environment, or a similarly configured EXE, it may be possible possible for that website to request the ActiveX control to upload the private key to the CA for key archival/escrow purposes.


1

Ultimately, many of the vulnerabilities noted in these answers come from mixing levels of trust. But if you understand how wildcard certs work, you can mitigate these vulnerabilities for particular use cases. I think that explaining this in more detail will improve the usefulness of this question and its answers. Unless all of the systems in your domain ...


1

There are mostly two main ways, one of which using certificate extensions, and one of which being a bad idea. These two are the same... In a certificate, you can encode "usages" as part of the Extended Key Usage extension. In your terminology, you would define some OIDs for actions A, B, C and D, and put only OIDs for A and C in the certificate. What is ...


0

In the Microsoft / Active Directory world, there are several ways by which certificate-based authentication may happen, but the short answer is: yes, a user can have several certificates. In IIS terminology, that is called "certificate mapping", with the option clientCertificateMappingAuthentication (not to be confused with ...


3

PKCS#12 is an extremely flexible format, so any answer to your question is relative to what the archive producer decided to do: which algorithms, which parameters... Normally, when doing password-based encryption, you will end up with 3DES or AES, and the key derivation algorithm is PBKDF2 with a cost parameter that you do not get to choose. To make the ...


0

You can only make assumptions based on the contents of the Organization field (DV certificate will either have the domain or "Persona Not Validated" in the organization name field) or in the policy identifier if it is there. Certificate issuers do not follow any unified scheme to differentiate OV vs DV. So, with cURL, you will have to do write your own ...


2

X.509 security certificates are mainly about the authentication of the site providing it, i.e. you know the site is really the site it claims to be. This is why e.g. banks use certificates at a high trust level (which means they are signed by more certification authorities, signed by more established cas rather than unknown ones, etc.). Even without ...


3

There is a standard for STARTTLS in plain HTTP. Note that "STARTTLS" is still SSL; it merely modifies the dynamics, but no implementation complexity is avoided that way. Generally speaking, nobody uses STARTTLS for HTTP, mostly because it is less secure. Indeed, a very big part of SSL-for-Web-browsers is the visual feedback, by which the user is made aware ...


0

I think you misunderstood STARTTLS. This command just tells the other server, that the clients wants to do TLS and after the server agreed the normal TLS handshake will start, e.g. with certificates and all the stuff - same as with https. The main difference is, that you don't commit to TLS right after TCP connect, but only after exchanging some plain text ...


0

You shouldn't. The reason being, the https:// URI scheme signals both to the user and to the browser that it is acting in a secure environment, and precautions should be taken to prevent secure information from leaking to an insecure environment. This is well-understood and a pretty strong system. The mechanism a server would use for switching from an ...


1

the common name cannot be an IP address. You may put IP addresses into the subject alternative name section, but as IP address not DNS the certificate might need a CA=true property if you want to import it as authority, simply self-signing might not be enough. You might still be able to import it and it will show up, but does not work. it failed for me for ...



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