5 ms·

This is pretty similar to my own thoughts on the matter that came from thoughts about doing something similar (mostly to make sure there’s not random malware fr

This is pretty similar to my own thoughts on the matter that came from thoughts about doing something similar (mostly to make sure there’s not random malware from family members). Imagine being in corp information security though. It seems like it won’t be long before command and control or exfiltration happens via certificate pinned apps you learn you can’t inspect. Corporate networks will have to start banning them if they don’t have a way for them to inspect.

mr_toad 8y ago
Honestly, if corporate IT has to drop connections to a bank, because they can’t MiTM the connection, I see this as a good thing. Too many people are unaware that their connections to their banks etc from work are insecure because of corporate firewalls and what are (essentially) compromised certificate stores.
- tialaramex 8y ago
  It's not uncommon with TLS 1.2 to have a setup where what actually happens is this: You make an outgoing TLS connection, the MITM Proxy Meg intervenes, but you actually wanted MyBank You->Meg (thinking she's MyBank): Hi, I'm looking for MyBank? Meg->MyBank: Hi, I'm looking for MyBank? MyBank->Meg: Yes, we're MyBank <cert for MyBank> [ Meg inspects the cert ] Meg->You: Yes, we're MyBank <cert for MyBank> Now Meg stitches the TCP connection back together so you're talking to MyBank. She no longer eavesdrops. This works for the business because now they're not paying for a box that can proxy your connection _and_ they're less likely to find that one of their "security" employees emptied your bank account. They feel comfortable that MyBank aren't bad guys, so they aren't scared that you'll, say, exfiltrate stolen corporate secrets via MyBank or download Malware from it. In TLS 1.3 this doesn't work, because the conversation goes like this: You->Meg (thinking she's MyBank): Hi, I'm looking for MyBank and I picked 14, and the letter Q Meg->MyBank: Hi, I'm looking for MyBank and I picked 14, and the letter Q MyBank->Meg: Cool, I picked a Banana and 209. <Unintelligible encrypted data> [ Meg can't do anything with this ] Or Meg could try picking her own Elliptic Curve Diffie Hellman values: You->Meg (thinking she's MyBank): Hi, I'm looking for MyBank and I picked 14, and the letter Q Meg->MyBank: Hi, I'm looking for MyBank and I picked 81, and the letter Z MyBank->Meg: Cool, I picked a Banana and 209. <We're MyBank - encrypted data> [ Meg now has a connection to MyBank, but she can't give it you because it doesn't work if you picked different values ] In the medium term we expect corporations which do this will just clamp everything to TLS 1.2 with full proxying. This will be very expensive, and worse, but well, we did tell you not to do this, so now that's broken you get to keep both halves. Ordinary folks who aren't trying to put middleboxes everywhere get TLS 1.3, with better performance and more security.
  - exikyut 8y ago
    I liked that explanation. So... with TLS 1.3, it won't be possible to do connection-jockey anymore, will it? (This is why I was saying things were such a mess earlier)

mr_toad 8y ago

Honestly, if corporate IT has to drop connections to a bank, because they can’t MiTM the connection, I see this as a good thing. Too many people are unaware that their connections to their banks etc from work are insecure because of corporate firewalls and what are (essentially) compromised certificate stores.

tialaramex 8y ago
It's not uncommon with TLS 1.2 to have a setup where what actually happens is this: You make an outgoing TLS connection, the MITM Proxy Meg intervenes, but you actually wanted MyBank You->Meg (thinking she's MyBank): Hi, I'm looking for MyBank? Meg->MyBank: Hi, I'm looking for MyBank? MyBank->Meg: Yes, we're MyBank <cert for MyBank> [ Meg inspects the cert ] Meg->You: Yes, we're MyBank <cert for MyBank> Now Meg stitches the TCP connection back together so you're talking to MyBank. She no longer eavesdrops. This works for the business because now they're not paying for a box that can proxy your connection _and_ they're less likely to find that one of their "security" employees emptied your bank account. They feel comfortable that MyBank aren't bad guys, so they aren't scared that you'll, say, exfiltrate stolen corporate secrets via MyBank or download Malware from it. In TLS 1.3 this doesn't work, because the conversation goes like this: You->Meg (thinking she's MyBank): Hi, I'm looking for MyBank and I picked 14, and the letter Q Meg->MyBank: Hi, I'm looking for MyBank and I picked 14, and the letter Q MyBank->Meg: Cool, I picked a Banana and 209. <Unintelligible encrypted data> [ Meg can't do anything with this ] Or Meg could try picking her own Elliptic Curve Diffie Hellman values: You->Meg (thinking she's MyBank): Hi, I'm looking for MyBank and I picked 14, and the letter Q Meg->MyBank: Hi, I'm looking for MyBank and I picked 81, and the letter Z MyBank->Meg: Cool, I picked a Banana and 209. <We're MyBank - encrypted data> [ Meg now has a connection to MyBank, but she can't give it you because it doesn't work if you picked different values ] In the medium term we expect corporations which do this will just clamp everything to TLS 1.2 with full proxying. This will be very expensive, and worse, but well, we did tell you not to do this, so now that's broken you get to keep both halves. Ordinary folks who aren't trying to put middleboxes everywhere get TLS 1.3, with better performance and more security.
- exikyut 8y ago
  I liked that explanation. So... with TLS 1.3, it won't be possible to do connection-jockey anymore, will it? (This is why I was saying things were such a mess earlier)