I have created a self-signed certificate to sign my program.
I noticed that importing the certificate using:
certutil.exe -addstore root "Tmp.crt"
Makes UAC warnings "more friendly" (showing the publisher name, without paying hundreds to Certificate Authorities.
My program is dedicated for a small group of people. Is it safe to create a prompt asking users if they want to install the certificate to the "Trusted Root Certification Authorities" store? Assuming they already trust the program enough to allow starting with administrative permissions.
If they import and trust your self-signed certificate, they are explicitly asked to trust you.
If you use a code signing certificate from an "official" (= paid-for) certificate authority, they are not asked to trust you explicitly, but they trust your certificate implicitly through that certificate authority. They have never been asked if they trust that authority, because it's trusted by the operating system for them.
As a consequence, I can't see how asking to trust your self-signed certificate would be more unsafe than relying on someone else's decision to trust a certificate authority. The only downside is that the user might be disconcerted by being asked something they are not usually asked.
You can increase security by making your program check the certificate it's been signed with to make sure it's indeed the one you self-signed.
It's not wrong but it could be unsafe if they are not getting your application from a trusted source. You could instead request a free certificate from the Let's Encrypt project. Here is a link to their getting started page:
Let's Encrypt Getting Started
Related
I'm curious when is "Trusted People" and "Trusted Devices" folder used in the Windows Certificate Store. I'm asking because I need to store Leaf (Personal) Certificates of other parties somewhere. This is a desktop application, I don't want to implement some kind of own store, using the Windows Cert Store seems reasonable.
I need to store the Certificate of other parties as kind of a certificate pinning feature. So the TLS connection would only be accepted if the Certificate chain is valid (I trust the root of the sent certificate) and the certificate that I got from the server is also there in either in the "Trusted People" or "Trusted Devices". My only concern is that I don't know what Windows uses these folders for.
Thank you
It is a set of certificates that are implicitly trusted, even without a trusted root signature on them.
It is safer to use than trusting a certificate as a root, since certificates signed by certificates in the Trusted People store won't also be trusted.
Be aware, though, that not all applications are aware of this certificate store, so it's not ideal to rely on it.
I have a portofolio website runing on a IIS Windows server if that matters.But some people complained that they get "website unsafe" when navigating the website.I personaly didnt get that error , and I tried the website on other diveces and they didnt get it either.
Could have something to do with SSL Certificate ? I didn't bought one ,but I have a self signed certificate according to ssl checker
.Do I need to buy a trusted SSL Certificate ? Or is there another problem ?
On my website i have a "Contact us" page with a web form that users should fill with name,email...
EDIT: I don't know if it's ok to post the website link here, if it's needed let me know .
EDIT: Link to website here.
This is a general problem with self-signed certificates, as the visitors of you website, or their browser, are not able to verify the identity of your server. The reason for this is, that there is no Certification Authority that signed it, thus the browser does not have a (root) certificate that is in the chain of trust linked to your certificate.
This problem with self-signed certificates is well explained in this post
The risks are for the client. The point of the SSL server certificate is that it is used by the client to know the server public key, with some level of guarantee that the key indeed belongs to the intended server. The guarantee comes from the CA: the CA is supposed to perform extensive verification of the requester identity before issuing the certificate.
When a client (the user and his Web browser) "accepts" a certificate which has not been issued by one of the CA that the client trusts (the CA which were embedded in Windows by Microsoft), then the risk is that the client is currently talking to a fake server, i.e. is under attack. Note that passive attacks (the attacker observes the data but does not alter it in any way) are thwarted by SSL regardless of whether the CA certificate was issued by a mainstream CA or not.
On a general basis, you do not want to train your users to ignore the scary security warning from the browser, because this makes them vulnerable to such server impersonation attacks (which are not that hard to mount, e.g. with DNS poisoning). On the other hand, if you can confirm, through some other way, that the certificate is genuine that one time, then the browser will remember the certificate and will not show warnings for subsequent visits as long as the same self-signed certificate is used. The newly proposed Convergence PKI is an extension of this principle. Note that this "remembered certificate" holds as long as the certificate is unchanged, so you really want to set the expiry date of your self-signed certificate in the far future (but not beyond 2038 if you want to avoid interoperability issues).
It shall be noted that since a self-signed certificate is not "managed" by a CA, there is no possible revocation. If an attacker steals your private key, you permanently lose, whereas CA-issued certificates still have the theoretical safety net of revocation (a way for the CA to declare that a given certificate is rotten). In practice, current Web browser do not check revocation status anyway.
I have a simple question (maybe stupid) and i didn't find any clear answer to it. If i get a certificate from a trusted signing company (like verisign...) for one of my server (web for instance), i'll have private an public keys. With this certificate can i set up my own intermediate CA and sign cert request and the be trusted by every one (i know that's shouldn't be..)? My real question is : what will prevent me for issuing certificate and how the company can garanty that nobody does ??
Thanking in advance!
The certificate issued for your web site is suitable for SSL/TLS and is not suitable for issuing other certificates (Key Usage field is different). Consequently while you technically can generate another certificate using yours as a CA, such generated certificate won't be trusted by properly implemented and configured validators (those that check Key Usage).
You are not paying verisign or other certificate organisation for the certificate publishing but for the certificate validation, this meens that they have web services that respond if your certificate is valid or not, if it is still active and not expired and your contact information as requested.
Unfortunatly this is something you have to live with it and pay them if you really need ssl over your site.
I have used a homemade certificate for my lan server and when i visit this https site a big red warning notifies me that this site is malicious and it has not a valid certificate. This doesn't bother me but I am sure that all of my clients would have freeked out if they see such a bold warning popping up to their browser.
what can you do? it's a companies' world
I want to use SSL (https) to secure communication. Is it possible to do it without buying a certificate of some sort?
You can use a self-signed certificate (google it) but your users will get a message saying the certificate is not valid. The traffic will still be encrypted, however.
The reason you have to pay a third party for a "valid" SSL certificate is that part of the purpose of an SSL certificate is to verify the authenticity of your server. If any body could issue an SSL cert with any information they wanted, what's to prevent me from setting up an SSL certificate using Walmart.com's contact information and tricking users into thinking my site is a branch of walmart.com?
In short, you can get the encryption part for free, but if you want to avoid browser identity warnings, you'll need to pay for a third party cert.
You can self sign a cert, or get one from cacert.org or a related free signing community. Most browsers will throw up warnings, so you shouldn't do it for production (if you are an ebusiness), but during development, or if you don't care about the warnings, it's a cheap alternative
As others have said, you can simply and easily use self-signed certificates or set up your own certificate authority (CA) and then issue as many certificates as you want. All these certificates are as valid as the "commercial" ones issued by the big CAs, so there is no technical difference between your certificate and the one from, say, verisign.
The reason most browsers and other client applications warn about your certificate is, that they do not know and therefore not trust your CA. Browsers usually come with hundreds of well-known CA certificates everyone automatically trusts (if thats a good thing, well...), so you don't get a warning when visiting amazon.com via HTTPS. In Firefox, you can go to "Preferences" > "Advanced" > "Encryption" > "View Certificates" to see which CAs or individual certificates your browser currently trusts.
In the end, it's a question of whom you and the users of your service trust. If your users know and trust you (say in company network or a small development team), they can add your CAs certificate to the trusted certificates in their browser. From then, every certificate issued by your own CA will generate no warning and will be trusted just like every other certificate.
A friend of mine asked me why we pay so much for SSL certificates if everyone could theoretically issue one. Why indeed? And how do we judge if the little lock in the browser is really trustworthy?
Certificates are cryptographically signed by something called a Certificate Authority(CA), and each browser has a list of CAs it implicitly trusts. These CAs are entities that have a set of cryptographic keys that can be used to sign any certificate, often for a fee. Any certificate signed by a CA in the trusted list will give a lock on a browser, because it's proven to be "trusted" and belongs to that domain.
You can self-sign a certificate, but the browser will warn you that the signer is not trusted, either by showing a big error box before allowing you in, or showing a broken lock icon.
In addition, even a trusted certificate will give an error if it's used for the wrong domain, or is modified to include another domain. This is ensured because the certificate includes the domains it is allowed to be used for, and it also has a cryptographic checksum/fingerprint that ensures its integrity.
This is not 100% safe at the moment, as there is the possibility to fake CA certificates that use MD5, see this link: http://www.phreedom.org/research/rogue-ca/. Though it has to be noted that this is pretty hard, as they exploited a weakness in an already existing CA, which may or may not have been closed by now.
In essence, we trust the certificates as much as we trust that our browser providers know how to select "proper" CAs. Those CAs are only trusted on virtue of their reputation, as a single misstep theoretically would be a very heavy blow on their trustworthiness if detected.
The whole CA business is amazing. I've purchased a couple of certificates from rapidssl.com, and all the "proof" they required was:
I could receive mail to the domain.
I could answer my phone.
That was it. Keep in mind, when trusting the little locks in the browser.
First, some background on strong public/private key cryptography, which SSL is based on:
A key has two parts, the private part and the public part. The public key can be used to encrypt material that requires the private key to decrypt. This allows the use of open communication channels to communicate securely.
One important aspect of public/private key cryptography is that the private key can be used to digitally sign a message which can be verified using the public key. This gives the receiver of a message the ability to verify concretely that the message they received was sent by the sender (the holder of the key).
The key to SSL certificates is that encryption keys themselves can be digitally signed.
A "certificate" is composed of a private/public key pair as well as digitally signed data. When someone buys an SSL certificate they generate a private/public key and submit the public key to a Certification Authority (CA) to be signed. The CA performs an appropriate level of due diligence on the buyer of the SSL certificate and signs the certificate with their private key. The SSL certificate will be bound to a particular website or set of websites and is essentially the CA indicating that they trust the owner of the private key of the certificate to be the proper owner of those websites.
The root certificates (public keys and other meta-data) for trusted CAs are included by default in major shipping browsers and operating systems (in windows, type "certmgr.msc" into a run prompt to see the certificate manager). When you connect to a web server using SSL the server will send you its SSL certificate including the public key and other meta data, all of which is signed by the CA. Your browser is able to verify the validity of the certificate, through the signature and the preloaded root certificates. This creates a chain of trust between the CA and the web server you are connecting to.
Because we have to trust someone.
Trusted SSL certificates have signatures of trusted authorities. For example, VeriSign has a deal with Microsoft, that their certificate is built in your browser. So you can trust every page with a VeriSign trusted certificate.
This graphic really picks the point:
RA = Registration Authority
CA = Certification Authority
VA = Validation Authority
Rough outline: A user applies for a
certificate with his public key at a
registration authority (RA). The
latter confirms the user's identity to
the certification authority (CA) which
in turn issues the certificate. The
user can then digitally sign a
contract using his new certificate.
His identity is then checked by the
contracting party with a validation
authority (VA) which again receives
information about issued certificates
by the certification authority.
If you are not using one of the accepted CAs people will get a message box when accessing the site talking about an untrusted certificate. That won't help to generate traffic to the site.
The lock only means that the site owner showed a CA some kind of proof that he really is who he claims to be. You must judge on your own if you trust that person/site.
It's like a stranger showing you a photo ID. Do you trust him more because you know for sure his name is John Doe? Probably not.
But when people you trust told you: "John Doe" is a good guy. The proof that the guy in front of you actually IS "John Doe", than you might choose to trust him as well.
Why? Because you're paying to ride along on someone elses reputation.... to vouch for you.
Its all about whose validating your claim to be you. Despite some of the documentaries Ive watched lately, and the recession, I'm still more likely to believe corporate America when they confirm your identity to me, than I am the Russian mafia. Even though both can just as easily issue certificates.
The amount you pay is basically just (how much it costs them to secure that reputation and/or suppress any security breaches) + (however much they can afford to gouge the market as a margin %).
Now the barriers to entry are quite high, cos its really expensive to earn that trust, so theres not a lot of competition. Therefore chances are the price isn't going to fall anytime soon.... unless Sony or GE etc decide to play.
You pay for a certificate so that when you go HTTPS (which you should for anything a little sensitive) your clients don’t get big warnings and go call your support saying that you have infected them & al…
Very little security, lot of FUD.
If you have the possibility of giving your clients your own certificate directly, do it. But it is a rare case.
Let's create an attack scenario.
Suppose the DNS was corrupted and https://facebook.com/ points to attacker's IP.
You sit down to your PC and open Facebook to loose few minutes on pointless scrolling. And then BANG, Certificate invalid error shows on your screen. Attacker signed https://facebook.com/ with his own cert to make sure no one will leave his copied facebook page because it's not encrypted so it looks suspicious. If browser wouldn't check certificate's authority, then attacker could sign corrupted page with his cert and you won't be aware you're connecting to the wrong IP.
So the attacker has 2 options to choose from:
Sign corrupted facebook page with his cert, so users will see an error.
Don't use https on his corrupted page.
Certificates are built on a chain of trust, and if let anyone be a signing authority, we would be implicitly trusting everyone. It's a bit scary today though, since there are over 200 so called "trusted authorities" whose certs are built into your browser!
There is one free CA that I know of though: StartCom. They issue free SSL certs, but they are only accepted in Firefox, not IE. (Not sure about Safari or Opera).
The other answers have explained the CA-system. The perspectives project aims to deploy a new approach to SSL, where you can choose whom to trust: http://perspectives-project.org/