Hello Michael/Anyone Else,
Can you be kind enough to please point me to some place/URL where I can
get a bit more information about how the key is negotiated upon ?
I have gone through a a couple of write-ups on OpenSSL which throw light
upon everything else except for this vital piece of information.
Thanks & Regards
Manish Jain
On 07-Jan-12 19:23, Michael S. Zick wrote:
On Sat January 7 2012, Manish Jain wrote:
Hi,
I am new to OpenSSL and am trying to prepare some illustrative
documentation on how it works.
AFAIK, OpenSSL uses the concept of a pair of keys per host : one is a
private key which is never communicated to any other host, and the other
is a public key which is transmitted to the peer (the other party). The
client uses the public key of the server (contained in the server's
certificate) to encrypt its communication, which can only be decrypted
with the server's private key. Please correct me if I am wrong.
That is the essence of what happens and by that the client knows
that it is communicating with the server it intended to reach (authentication).
Now the question is : when the server sends data to the client, what key
does it use for encryption ?
The general answer is: The client and server establish a shared key
for that propose early in the protocol.
Does the client communicate its public key
to the server (at some initial stage) which the server uses for
encryption ?
If the communications set up between the two requires client authentication.
In many cases the client remains a stranger to the server (un-authenticated).
If yes, what if the client does not have a pair of
public/private keys ?
The usual case for public web browsing using https and some other protocols.
The client remains a stranger to the server.
The question arises because it does not seem logical that the server
would its private key for encrypting data to be sent to the client.
Else, snoopers who might have picked the public key could decrypt the
data too.
There is an early stage in nearly all protocols, called: key agreement
where the client and server agree on a key without exchanging any of
the 'private' information that it is based on.
Any help on clearing up the above points would be greatly appreciated.
My comments above are at a very general level.
If the process was as simple as my answers, OpenSSL would not be as
large a body of code as it is. ;-)
Mike
Thank you&
Regards
Manish Jain
invalid.poin...@gmail.com
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______________________________________________________________________
OpenSSL Project http://www.openssl.org
User Support Mailing List openssl-users@openssl.org
Automated List Manager majord...@openssl.org
______________________________________________________________________
OpenSSL Project http://www.openssl.org
User Support Mailing List openssl-users@openssl.org
Automated List Manager majord...@openssl.org
