Обсуждение: SSL without verifying server certificate

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Oliver Nolden wrote:
> Hi everyone,
>
> I want to realize a secure database connection with jdbc and SSL
> between an applet and a postgres database 7.4. The driver pg74jdbc3.jar
> supports SSL, I created the server certificates with OpenSSL. The
> postgres server works fine with ssl. To establish a ssl connection with
> the client, you have to import the self-signed certificate to the
> client`s machine.
>
> Now my question: Is it possible to establish a ssl connection without
> importing the server certificate to the client machine? i.e. that
> the jdbc driver does not verify the self-signed server certificate?
> Thereby I could use the applet on every computer.

If you do this, you become vulnerable to man-in-the-middle attacks.
Might as well just use an unencrypted connection in the first place.

-O

 > If you do this, you become vulnerable to man-in-the-middle attacks.
Might as well just use an unencrypted connection > in the first place.

Well, a man-in-the-middle attack is non-trivial since it typically means
stealing a domain name.  And with an encrypted channel, at least
userid/passwords are nicely encrypted as is the data in the database.  I
think a simple sniffer type attack is far easier.  But you are right
that having the client import the cert (or using a well-known CA signed
cert) is preferable.

David

>

On Mon, 16 Feb 2004, [iso-8859-1] Oliver Nolden wrote:

> Hi everyone,
>  I want to realize a secure database connection with jdbc and SSL
> between an applet and a postgres database 7.4. The driver
> pg74jdbc3.jar supports SSL, I created the server certificates with
> OpenSSL. The postgres server works fine with ssl. To establish a ssl
> connection with the client, you have to import the self-signed
> certificate to the client`s machine.

Java's ssl implementation requires authenticating the server I believe.
I think a better question to ask would be if there was any way to
programmatically supply the server's certificate instead of having to
import it into the cert.  Unfortunately I don't know the answer to that
question.

Kris Jurka

Kris Jurka wrote:
> Java's ssl implementation requires authenticating the server I
> believe. I think a better question to ask would be if there was any
> way to programmatically supply the server's certificate instead of
> having to import it into the cert.  Unfortunately I don't know the
> answer to that question.

IIRC, the place to look in modern versions of the J2SDK is
javax.net.X509TrustManager.  You can specify an X509TrustManager when you call
SSLContext.init.  You'd then need to get an SSLSocketFactory from that
SSLContext and finally create a socket using that SocketFactory.

Currently, org.postgresql.Driver.makeSSL obtains a default SSLSocketFactory by
calling the static method SSLSocketFactory.getDefault().  What we'd ideally do
here is leave that default in place, but allow a client to specify a different
SSLSocketFactory somehow.  All the dealing with X509TrustManager and
SSLContext could be left to the application code, since the right way to do it
is highly app-specific and security-sensitive.

Any opinions on the best way to specify that SSLSocketFactory?  Sticking with
URL parameters is unworkable, since we would like to specify a specific
instance obtained from the SSLContext, *not* a class name for a whole set of
these things.  We could add a method to Driver or to PGConnection, perhaps?

--
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The Easiest Way to Train Anyone... Anywhere.

Chris Smith - Lead Software Developer/Technical Trainer
MindIQ Corporation

 --- Oliver Jowett <oliver@opencloud.com> schrieb: >
Oliver Nolden wrote:

Thank for your answer. You're rigth, but for me the
authentication of the server is not important,
I only want a secure connection between applet and
database.

In the meantime I solved my problem: I modified the
postgres jdbc driver "pg74jdbc3", so that I can use it
for SSL connection without verifyinf the server
certificate, So I dont't have to import the server
certificate on the client machine. Now I can use the
applet on every machine.

If somebody is interested in, I could send him the
modified driver.

OLiver

> > Hi everyone,
> >
> > I want to realize a secure database connection
> with jdbc and SSL
> > between an applet and a postgres database 7.4. The
> driver pg74jdbc3.jar
> > supports SSL, I created the server certificates
> with OpenSSL. The
> > postgres server works fine with ssl. To establish
> a ssl connection with
> > the client, you have to import the self-signed
> certificate to the
> > client`s machine.
> >
> > Now my question: Is it possible to establish a ssl
> connection without
> > importing the server certificate to the client
> machine? i.e. that
> > the jdbc driver does not verify the self-signed
> server certificate?
> > Thereby I could use the applet on every computer.
>
> If you do this, you become vulnerable to
> man-in-the-middle attacks.
> Might as well just use an unencrypted connection in
> the first place.
>
> -O




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