"serge calderara" wrote:

> Dear all,
>
> I am sudying the SSL configuration of web site using certificate.
> On my reading it is mention that if an attacker  retrieve the certificate
> request file and install it on his machine, he can use it to decrypt the
> traffic between the initial web server and the client.
>
> What I have understand in this SSL mechanism is that when a web client send
> a request to the web server, the web server send back to the client the
> certificate public key as an asymetric encryption, the the client send back
> to the server a secret key encrypted with the receive plublic key. At this
> time a secret session key is created and used betwen the web server and the
> client to encrypt conversation using symetric encryption.
>
> How can it be possible then that an attacker who could get the certificate
> instaled on his machine, act as a man in middle ??
>
> Thnaks for your clarification on that point casue ai ma realy confused
>
> regards
> serge

"oldbear" wrote:

> Hi
>
> In order to decrypt information sent by the client that was encrypted with
> the certificate's public key, the attacker would have to have the private key
> that goes with it. The private key is not passed in the certificate request,
> so the attacker cannot decrypt incoming messages or sign outgoing ones.
>
> When IIS is used to create a certificate request, the following takes place.
>
> IIS generates a private/public key pair. It then submits the public key in a
> certificate request.
>
> The certificate request does not include the private key, nor does the reply
> from the certification authority (CA). The certificate request information
> includes:
> subject distinguished name;
> subject public key;
> a set of attributes (optional).
>
> This request information is then signed with the private key that
> corresponds to the public key in the request.
>
> The signature is then added to the request with details of the algorithm
> used to sign it.
>
> The signature proves to the CA that the sender has the private key that
> corresponds to the values in the request. At no time is the private key
> exchanged.
>
> According to RSA:
>
> 'The signature on the certification request prevents an entity from
> requesting a certificate with another party's public key. Such an attack
> would give the entity the minor ability to pretend to be the originator of
> any message signed by the other party. This attack is significant only if the
> entity does not know the message being signed and the signed part of the
> message does not identify the signer. The entity would still not be able to
> decrypt messages intended for the other party, of course.'
>
> Hope this helps
>
> --
> ----------------------------------
> Chris Seary
> http://blog.searyblog.com/
>
>
>
>
> "serge calderara" wrote:
>
> > Dear all,
> >
> > I am sudying the SSL configuration of web site using certificate.
> > On my reading it is mention that if an attacker  retrieve the certificate
> > request file and install it on his machine, he can use it to decrypt the
> > traffic between the initial web server and the client.
> >
> > What I have understand in this SSL mechanism is that when a web client send
> > a request to the web server, the web server send back to the client the
> > certificate public key as an asymetric encryption, the the client send back
> > to the server a secret key encrypted with the receive plublic key. At this
> > time a secret session key is created and used betwen the web server and the
> > client to encrypt conversation using symetric encryption.
> >
> > How can it be possible then that an attacker who could get the certificate
> > instaled on his machine, act as a man in middle ??
> >
> > Thnaks for your clarification on that point casue ai ma realy confused
> >
> > regards
> > serge

> Thnaks for your reply.
>
> Now I get confused. In the MS-PRess book relative tto the 70-330 exam
> based on .NEt security a chapter discuss about SSL configuration and
> Certificate.There is sample steps to follow in order to succeed that
> configuration. Works great.
>
> then at the end there is an important note mentionning :
>
> "Remove the certificate request file and store the SSL certificate
> file in a safe location. If an attacker retrievs the SSL certificate,
> he can use it to impersonate your server and decrypt traffic"
>
> how should I understand that ?
>
> regards
> serge
> "oldbear" wrote:
>
>> Hi
>>
>> In order to decrypt information sent by the client that was encrypted
>> with the certificate's public key, the attacker would have to have
>> the private key that goes with it. The private key is not passed in
>> the certificate request, so the attacker cannot decrypt incoming
>> messages or sign outgoing ones.
>>
>> When IIS is used to create a certificate request, the following takes
>> place.
>>
>> IIS generates a private/public key pair. It then submits the public
>> key in a certificate request.
>>
>> The certificate request does not include the private key, nor does
>> the reply
>> from the certification authority (CA). The certificate request
>> information
>> includes:
>> subject distinguished name;
>> subject public key;
>> a set of attributes (optional).
>> This request information is then signed with the private key that
>> corresponds to the public key in the request.
>>
>> The signature is then added to the request with details of the
>> algorithm used to sign it.
>>
>> The signature proves to the CA that the sender has the private key
>> that corresponds to the values in the request. At no time is the
>> private key exchanged.
>>
>> According to RSA:
>>
>> 'The signature on the certification request prevents an entity from
>> requesting a certificate with another party's public key. Such an
>> attack would give the entity the minor ability to pretend to be the
>> originator of any message signed by the other party. This attack is
>> significant only if the entity does not know the message being signed
>> and the signed part of the message does not identify the signer. The
>> entity would still not be able to decrypt messages intended for the
>> other party, of course.'
>>
>> Hope this helps
>>
>> --
>> ----------------------------------
>> Chris Seary
>> http://blog.searyblog.com/
>> "serge calderara" wrote:
>>
>>> Dear all,
>>>
>>> I am sudying the SSL configuration of web site using certificate.
>>> On my reading it is mention that if an attacker  retrieve the
>>> certificate
>>> request file and install it on his machine, he can use it to decrypt
>>> the
>>> traffic between the initial web server and the client.
>>> What I have understand in this SSL mechanism is that when a web
>>> client send a request to the web server, the web server send back to
>>> the client the certificate public key as an asymetric encryption,
>>> the the client send back to the server a secret key encrypted with
>>> the receive plublic key. At this time a secret session key is
>>> created and used betwen the web server and the client to encrypt
>>> conversation using symetric encryption.
>>>
>>> How can it be possible then that an attacker who could get the
>>> certificate instaled on his machine, act as a man in middle ??
>>>
>>> Thnaks for your clarification on that point casue ai ma realy
>>> confused
>>>
>>> regards
>>> serge

"serge calderara" wrote:

> Thnaks for your reply.
>
> Now I get confused. In the MS-PRess book relative tto the 70-330 exam based
> on .NEt security a chapter discuss about SSL configuration and
> Certificate.There is sample steps to follow in order to succeed that
> configuration. Works great.
>
> then at the end there is an important note mentionning :
>
> "Remove the certificate request file and store the SSL certificate file in a
> safe location. If an attacker retrievs the SSL certificate, he can use it to
> impersonate your server and decrypt traffic"
>
> how should I understand that ?
>
> regards
> serge
>
> "oldbear" wrote:
>
> > Hi
> >
> > In order to decrypt information sent by the client that was encrypted with
> > the certificate's public key, the attacker would have to have the private key
> > that goes with it. The private key is not passed in the certificate request,
> > so the attacker cannot decrypt incoming messages or sign outgoing ones.
> >
> > When IIS is used to create a certificate request, the following takes place.
> >
> > IIS generates a private/public key pair. It then submits the public key in a
> > certificate request.
> >
> > The certificate request does not include the private key, nor does the reply
> > from the certification authority (CA). The certificate request information
> > includes:
> > subject distinguished name;
> > subject public key;
> > a set of attributes (optional).
> >
> > This request information is then signed with the private key that
> > corresponds to the public key in the request.
> >
> > The signature is then added to the request with details of the algorithm
> > used to sign it.
> >
> > The signature proves to the CA that the sender has the private key that
> > corresponds to the values in the request. At no time is the private key
> > exchanged.
> >
> > According to RSA:
> >
> > 'The signature on the certification request prevents an entity from
> > requesting a certificate with another party's public key. Such an attack
> > would give the entity the minor ability to pretend to be the originator of
> > any message signed by the other party. This attack is significant only if the
> > entity does not know the message being signed and the signed part of the
> > message does not identify the signer. The entity would still not be able to
> > decrypt messages intended for the other party, of course.'
> >
> > Hope this helps
> >
> > --
> > ----------------------------------
> > Chris Seary
> > http://blog.searyblog.com/
> >
> >
> >
> >
> > "serge calderara" wrote:
> >
> > > Dear all,
> > >
> > > I am sudying the SSL configuration of web site using certificate.
> > > On my reading it is mention that if an attacker  retrieve the certificate
> > > request file and install it on his machine, he can use it to decrypt the
> > > traffic between the initial web server and the client.
> > >
> > > What I have understand in this SSL mechanism is that when a web client send
> > > a request to the web server, the web server send back to the client the
> > > certificate public key as an asymetric encryption, the the client send back
> > > to the server a secret key encrypted with the receive plublic key. At this
> > > time a secret session key is created and used betwen the web server and the
> > > client to encrypt conversation using symetric encryption.
> > >
> > > How can it be possible then that an attacker who could get the certificate
> > > instaled on his machine, act as a man in middle ??
> > >
> > > Thnaks for your clarification on that point casue ai ma realy confused
> > >
> > > regards
> > > serge

"oldbear" wrote:

> Hi
>
> Here's the PKCS information:
>
> http://www.rsasecurity.com/rsalabs/node.asp?id=2132
>
> I believe your book is instructing you to keep the private key secure. When
> you use the certificate request wizard in IIS to install the cert after it's
> been issued to you by the CA, have a look in the cert store. Double click on
> the certificate that's just been installed.
>
> The dialog that comes up shows that you have a private key that corresponds
> to the certificate. Keep this private key secure.
>
> The SSL certificate cannot let an intruder decrypt traffic. Only the private
> key can do this.
>
> Hope this helps
>
> --
> ----------------------------------
> Chris Seary
> http://blog.searyblog.com/
>
>
>
>
> "serge calderara" wrote:
>
> > Thnaks for your reply.
> >
> > Now I get confused. In the MS-PRess book relative tto the 70-330 exam based
> > on .NEt security a chapter discuss about SSL configuration and
> > Certificate.There is sample steps to follow in order to succeed that
> > configuration. Works great.
> >
> > then at the end there is an important note mentionning :
> >
> > "Remove the certificate request file and store the SSL certificate file in a
> > safe location. If an attacker retrievs the SSL certificate, he can use it to
> > impersonate your server and decrypt traffic"
> >
> > how should I understand that ?
> >
> > regards
> > serge
> >
> > "oldbear" wrote:
> >
> > > Hi
> > >
> > > In order to decrypt information sent by the client that was encrypted with
> > > the certificate's public key, the attacker would have to have the private key
> > > that goes with it. The private key is not passed in the certificate request,
> > > so the attacker cannot decrypt incoming messages or sign outgoing ones.
> > >
> > > When IIS is used to create a certificate request, the following takes place.
> > >
> > > IIS generates a private/public key pair. It then submits the public key in a
> > > certificate request.
> > >
> > > The certificate request does not include the private key, nor does the reply
> > > from the certification authority (CA). The certificate request information
> > > includes:
> > > subject distinguished name;
> > > subject public key;
> > > a set of attributes (optional).
> > >
> > > This request information is then signed with the private key that
> > > corresponds to the public key in the request.
> > >
> > > The signature is then added to the request with details of the algorithm
> > > used to sign it.
> > >
> > > The signature proves to the CA that the sender has the private key that
> > > corresponds to the values in the request. At no time is the private key
> > > exchanged.
> > >
> > > According to RSA:
> > >
> > > 'The signature on the certification request prevents an entity from
> > > requesting a certificate with another party's public key. Such an attack
> > > would give the entity the minor ability to pretend to be the originator of
> > > any message signed by the other party. This attack is significant only if the
> > > entity does not know the message being signed and the signed part of the
> > > message does not identify the signer. The entity would still not be able to
> > > decrypt messages intended for the other party, of course.'
> > >
> > > Hope this helps
> > >
> > > --
> > > ----------------------------------
> > > Chris Seary
> > > http://blog.searyblog.com/
> > >
> > >
> > >
> > >
> > > "serge calderara" wrote:
> > >
> > > > Dear all,
> > > >
> > > > I am sudying the SSL configuration of web site using certificate.
> > > > On my reading it is mention that if an attacker  retrieve the certificate
> > > > request file and install it on his machine, he can use it to decrypt the
> > > > traffic between the initial web server and the client.
> > > >
> > > > What I have understand in this SSL mechanism is that when a web client send
> > > > a request to the web server, the web server send back to the client the
> > > > certificate public key as an asymetric encryption, the the client send back
> > > > to the server a secret key encrypted with the receive plublic key. At this
> > > > time a secret session key is created and used betwen the web server and the
> > > > client to encrypt conversation using symetric encryption.
> > > >
> > > > How can it be possible then that an attacker who could get the certificate
> > > > instaled on his machine, act as a man in middle ??
> > > >
> > > > Thnaks for your clarification on that point casue ai ma realy confused
> > > >
> > > > regards
> > > > serge