Need the understanding about SSL and the way it functions. Kindly help answer the below.
I understand that the CSR that we generate has our public key and DN info i.e C=,CN=,L=,O=,OU=,ST=.
Are both these two compoments (JPMC public key and the DN) hashed and if the hash is also send to verisign at the time we request them for a cert (new cert or a cert renewal).
What amount these (public key, DN and the hash) are encrypted using JPMC's private key.
Does Verisign (CA) use the public key that we send them as part of the CSR or do they have it from other means inorder to decrypt whatever was encrypted above.
No, the information in a certificate signing request is not hashed - how could it be - you can't get the information back after hashing? It is not encrypted either, none of the information is sensitive.
A CSR contains the version of the PKCS#10 standard which is being used, the DN of the entity the certificate is for, the public key that will be used, and optionally, some attributes such as subject alternate names, etc.
The CSR is signed, using the private key generated to initiate the request (or, in renewal, the private key of the existing certificate).
PKCS#10 is the main specification for all of this.
Related
I was given a certificate from BaltimoreCyberTrustRoot but I wasn't given a key, Would I be able to generate a key for an existing certificate?
Obviously no you cannot generate a private key out of an existing certificate otherwise you would be able to impersonate basically any given HTTPS website (How? the certificate is public, you download it and magically create the associated private key and you have then a validated website for that certificate name...)
Normally generating a certificate works like this:
you generate a public/private key and the public key is used to compute a CSR or Certificate Signing Request which has the public key and some meta data
you give the CSR to the CA
the CA gives you back a certificate based on the content of the CSR, and signed by their own private key (so that by using the CA certificate - which has the corresponding CA public key - you can validate that this generated certificate was indeed signed/issued by this specific CA).
So you have the private key.
If you are on a case where the CA or the intermediate generates everything for you (which is bad security wise it means they have the private key and hence can impersonate YOU), then you have to ask them to send you both the certificate and the private key!
I have done some research on this but still have some trouble connecting the dots as to what exactly happens when the server send its certificate to the client in terms of verifying signature and root certificates.
When you create a CSR, it generates a private key along with it, and you send it to the CA to generate the cert and sign it, but doesn't the CA use it's own private key to sign? So what is the point of the private key you generated with your CSR?
When server sends its certificate for client to validate, how exactly does client validate that it is a valid CA cert. It has a collection of trusted CA certs, ok - but how exactly are they used to verify that it was a valid CA that signed the server's certificate using the signature and public key of the server certificate? What things are compared to make sure it was not forged?
Is there any point in encrypting your internal self signed certs? How about an internal root cert? Or is the private key the only one worth encrypting?
If we don't keep a database of encrypted data for our web service (over SSL) for example, would we ever care about storing our own private key once we generated the self signed cert, and if we do, they why?
When you create a CSR, it generates a private key along with it
Or you have already generated your own private key.
and you send it to the CA to generate the cert and sign it
You send the CSR. You don't send your private key. It's private. You don't send it to anyone.
but doesn't the CA use it's own private key to sign?
Yes.
So what is the point of the private key you generated with your CSR?
It pairs with the public key contained in the certificate and it is part of the process used to prove that you and only you own that certificate, as only you can generate digital signatures with that private key that can be verified by the public key in the certificate.
When server sends its certificate for client to validate, how exactly does client validate that it is a valid CA cert. It has a collection of trusted CA certs, ok - but how exactly are they used to verify that it was a valid CA that signed the server's certificate using the signature and public key of the server certificate? What things are compared to make sure it was not forged?
The certificate itself is verified, by verifying its digital signature; it is checked for being within its validity period; and then an attempt is made to form a certificate chain using the alleged signer of the certificate (the 'issuer') and the trusted certificates in the collection.
Is there any point in encrypting your internal self signed certs?
No. They are public documents. Only the private key is private, and that isn't in the certificate.
How about an internal root cert?
No.
Or is the private key the only one worth encrypting?
Yes.
If we don't keep a database of encrypted data for our web service (over SSL) for example, would we ever care about storing our own private key once we generated the self signed cert, and if we do, they why?
Because it's private. It is a critical part of your identity. If you leak it, others can impersonate you.
I am reading the following article about HTTPS:
http://www.moserware.com/2009/06/first-few-milliseconds-of-https.html
I do understand how we can verify that a signature was truly created by VeriSign.
But how can we know that VeriSign created this signature for this specific domain that we are connected to (or actually for this certificate)?
Since I can see the certificate, including the signature, what stops me from creating my own certificate, replacing the signature with the one I saw on the Amazon.com certificate, and pretending to have a certificate signed by VeriSign?
Since I can see the certificate, including the signature, what stops me from creating my own certificate, replacing the signature with the one I saw on the Amazon.com certificate, and pretending to have a certificate signed by VeriSign?
A certificate has a subject, public key, issuer and signature (among other fields). For example, a subject might be example.com (a DNS name) or joe#example.com (and email address), and the issuer might be Startcom. The issuer's signature binds the subject's public key to the subject. That's all a certificate does: it binds a public key to an entity through an authority's signature. The authority is often called "trusted" or "trusted third party".
So the person who is validating the certificate you are trying to forge will extract the issuer, get the issuer's public key (that's in a different certificate), and then use the issuer's public key to verify your certificate data. Since you forged the signature (i.e., used a different public key than that of the issuer), the signature verification will fail.
Because the public key with which you can verify the signature is part of the certificate and also part of the signature. So you can't change any of those things without breaking the signature.
#gilden But I do not try to create a new signature. I use (almost) exactly the same certificate amazon sent me when I tried to https-contact its website (so same signature and same public key as on amazon's cert). The only thing I change on that cert is the name field (i.e. the name of the website/computer who was given the authority by the signer to use this cert to authenticate itself). So I'm going to change this field from "amazon.com" to "rapt.com". Now I can use this cert to convince people rapt.com is a trusted website. What in the SSL algorithm is going to make me fail in my scheme?
Then the browser/client will use the amazon.com public key to communicate with your server, for which you do not have the corresponding private key. Hence you will not be able to decrypt the pre_master_secret from the client certificate message, and the ssl/tls handshake will fail.
Amazon Cloudfront is giving me errors, either my private key doesn't match my public key certificate or my public key certificate cannot be parsed as it's invalid.
Using Godaddy for my SSL certificate middle man/provider, I got a:
.pem whoose contents beings with "-----BEGIN RSA PRIVATE KEY-----"
(I'm assuming that's my private key)
Inside Godaddy I am able to download some certs for the SSL, they are:
.crt (type = Security Certificate)
.p7b (type = PKCS #7 Certificate)
Is one of the above my public key? Or is there another way I am supposed to get my public key?
I have encountered this issue before with bad CSR Request.
According to GoDaddy:
To install a digital certificate, you must first generate and submit a Certificate Signing Request (CSR) to the Certification Authority (CA). The CSR contains your certificate-application information, including your public key. Use your Web server software to generate the CSR, which will also create your public/private key pair used for encrypting and decrypting secure transactions.
http://support.godaddy.com/help/article/5343/generating-a-certificate-signing-request
It also states: NOTE: When generating your CSR, specify a key size of 2048 or higher.
The key size is sometimes the culprit. Hope it helps.
As I understand, the root of SSL security is based on the public key of certificate authority. And I don't know why this key can be faked by a man in the middle:
The man in the middle received this CA public key but then sends me a public key and fake certificate of his own and pretends that it is valid. I use this key to compute the certificate signature to verify it but if this key is fake, how can I know certificate is not from a trusted source?
In order for any PKI to work, each party should have a list of public keys for CA they trust. These keys have been obtained out of band, securely, from a software vendor.
The SSL certificate (containing the SSL server's public key) received from the server is signed by the private key of one of AC. There is no way to forge a valid certificate without access to one of the CA's private key, so the man in the middle can not send a forged one that will look valid.
The is two things that we need trust in order to use PKI :
1/ that we can securely retrieve the CA's public keys
2/ that the CA won't mess up by signing forged certificates or by getting their keys stolen.