3 ms·

For the uninformed, what does this mean? (Btw, I did read the post; I just didn't understand it.)

mbrubeck 15y ago
This Ars article from last week gives some context and explanation: http://arstechnica.com/business/news/2012/02/critics-slam-ssl-authority-for-minting-cert-used-to-impersonate-sites.ars http://arstechnica.com/business/news/2012/02/critics-slam-ss... In short, at least one CA, Trustwave, has issued a "subordinate CA certificate" (which allows another party to issue certs which will be trusted as if they were from Trustwave) to a network admin who used it to create forged certificates and intercept SSL traffic on their internal network.
- dmboyd 15y ago
  Has there been any talk about which company received the subordinated cert? The excuse for it being used in an internal network only doesn't really hold any weight due to the ability to install custom certs on all web browsers.
  - LaGrange 15y ago
    This way even user-installed browsers would accept the subordinated cert. It's one of those things I believe should be prosecuted.
matkam 15y ago
Apparently some root certificate authorities have been issuing certificates that lets others generate their own, valid certificates at their own discretion. Sounds these subordinate CA certificates are being used for SSL man-in-the-middle attacks (http://en.wikipedia.org/wiki/Man-in-the-middle_attack http://en.wikipedia.org/wiki/Man-in-the-middle_attack). So say your employer wants to monitor everything you're doing at work. In order to get around the fact that a lot of your network data is encrypted, they put in a device between your network connection and the internet that looks at all your network traffic. For any connection that is SSL encrypted (like https pages), it will forge its own valid certificate, and use it to prove to your web browser (etc) that nothing is wrong with the connection. Meanwhile, its logging the content of your Gmail, etc.
- astrodust 15y ago
  This is the unfortunate flaw with SSL and TLS. The certificates are bound only to the "domain name" which is a wobbly concept at best without DNSsec to validate your DNS responses. Anyone clever enough to create a DNS redirector that turns paypal.com into 10.0.0.2 on their closed network could also create an accompanying SSL certificate that they own for paypal.com and you'd be none the wiser as they proxy all of your traffic through their server, logging every bit of it.
  - jvdongen 15y ago
    And even if the IP address is unaltered - what will prevent the owner of the closed network from routing every http(s) request silently through a proxy on its way out to the Internet?
  - omgtehlion 15y ago
    If you have a router with “deep packet inspection” there’s no need to change IP address.
    - icebraining 15y ago
      Or if you just set up a transparent HTTP proxy.
  - tptacek 15y ago
    Wait, what? No they can't. The whole point of SSL/TLS is that you don't trust the DNS. The only way an attacker can redirect DNS for Paypal and have a valid-looking CA for Paypal is if they compromise a CA root certificate. That's the point of SSL/TLS. Before you suggest "but we can't trust the CAs", note two things: (1) if you don't trust the CA, SSL/TLS isn't doing anything for you anyways, and (2) DNSSEC also has a hierarchical PKI in which you are required to trust commercial enterprises --- or governments, explicitly.
    - astrodust 15y ago
      SSH has more robust security than SSL seems to if only because once you've established a connection with a remote host, whereupon their public key is displayed and validated, it can be saved as "trusted". The same principle doesn't seem to apply for SSL in browsers where, so long as it's signed by a "trusted" authority, there's no question the certificate is valid. There has to be a better way than this.

This Ars article from last week gives some context and explanation: http://arstechnica.com/business/news/2012/02/critics-slam-ssl-authority-for-minting-cert-used-to-impersonate-sites.ars http://arstechnica.com/business/news/2012/02/critics-slam-ss... In short, at least one CA, Trustwave, has issued a "subordinate CA certificate" (which allows another party to issue certs which will be trusted as if they were from Trustwave) to a network admin who used it to create forged certificates and intercept SSL traffic on their internal network.

dmboyd 15y ago
Has there been any talk about which company received the subordinated cert? The excuse for it being used in an internal network only doesn't really hold any weight due to the ability to install custom certs on all web browsers.
- LaGrange 15y ago
  This way even user-installed browsers would accept the subordinated cert. It's one of those things I believe should be prosecuted.

matkam 15y ago

Apparently some root certificate authorities have been issuing certificates that lets others generate their own, valid certificates at their own discretion. Sounds these subordinate CA certificates are being used for SSL man-in-the-middle attacks (http://en.wikipedia.org/wiki/Man-in-the-middle_attack http://en.wikipedia.org/wiki/Man-in-the-middle_attack). So say your employer wants to monitor everything you're doing at work. In order to get around the fact that a lot of your network data is encrypted, they put in a device between your network connection and the internet that looks at all your network traffic. For any connection that is SSL encrypted (like https pages), it will forge its own valid certificate, and use it to prove to your web browser (etc) that nothing is wrong with the connection. Meanwhile, its logging the content of your Gmail, etc.

astrodust 15y ago
This is the unfortunate flaw with SSL and TLS. The certificates are bound only to the "domain name" which is a wobbly concept at best without DNSsec to validate your DNS responses. Anyone clever enough to create a DNS redirector that turns paypal.com into 10.0.0.2 on their closed network could also create an accompanying SSL certificate that they own for paypal.com and you'd be none the wiser as they proxy all of your traffic through their server, logging every bit of it.
- jvdongen 15y ago
  And even if the IP address is unaltered - what will prevent the owner of the closed network from routing every http(s) request silently through a proxy on its way out to the Internet?
- omgtehlion 15y ago
  If you have a router with “deep packet inspection” there’s no need to change IP address.
  - icebraining 15y ago
    Or if you just set up a transparent HTTP proxy.
- tptacek 15y ago
  Wait, what? No they can't. The whole point of SSL/TLS is that you don't trust the DNS. The only way an attacker can redirect DNS for Paypal and have a valid-looking CA for Paypal is if they compromise a CA root certificate. That's the point of SSL/TLS. Before you suggest "but we can't trust the CAs", note two things: (1) if you don't trust the CA, SSL/TLS isn't doing anything for you anyways, and (2) DNSSEC also has a hierarchical PKI in which you are required to trust commercial enterprises --- or governments, explicitly.
  - astrodust 15y ago
    SSH has more robust security than SSL seems to if only because once you've established a connection with a remote host, whereupon their public key is displayed and validated, it can be saved as "trusted". The same principle doesn't seem to apply for SSL in browsers where, so long as it's signed by a "trusted" authority, there's no question the certificate is valid. There has to be a better way than this.