6 ms·

Hmm... did this site get served a secret warrant last week? Or did they just forget to update their warrant canary? https://mediacru.sh/transparency/warrant-ca

by graue 13y ago

Hmm... did this site get served a secret warrant last week? Or did they just forget to update their warrant canary? https://mediacru.sh/transparency/warrant-canary.txt https://mediacru.sh/transparency/warrant-canary.txt (Note: the date 08/11 is written European style meaning November 8th, as you can see if you go up a directory.)

Sir_Cmpwn 13y ago
Ack! My other half is responsible for the warrant canary. He keeps forgetting it. We may as well not even have it. It doesn't mean much without a signature, but I assure you that we have never been served a warrant.
- laureny 13y ago
  Nice try, NSA.
  - Sir_Cmpwn 13y ago
    Well, even if we had been served a warrant, I dunno what we'd give them. We don't store anything about our users. https://blog.mediacru.sh/2013/07/19/MediaCrush-for-nerds.html https://blog.mediacru.sh/2013/07/19/MediaCrush-for-nerds.htm...
    - deleted 13y ago
      [deleted]
      - Sir_Cmpwn 13y ago
        How do I word it? As of November 11th, 2013, neither MediaCrush nor its admins have ever received any sort of warrant, or any other kind of notice or request, from the government of any country. Additionally, we do not store anything about a user who visits our site. Here's an example from the HTTP log: [21/Nov/2013:06:59:36 +0000] "GET /static/favicon.ico HTTP/1.1" 200 16958 "-" 0.000 When you upload a file, your IP address is run though bcrypt (12 rounds) and saved with the file information in redis. Reversing bcrypt is infeasible with modern technology (and probably for many years to come). We store nothing else about you.
        gunn 13y ago
        Is there a reason a complete IP address rainbow-table wouldn't defeat this?
        Sir_Cmpwn 13y ago
        bcrypt is designed to thwart rainbow-table attacks. It salts the hashes and it takes a while (1/3 of a second on my machine) to compute a single hash. https://en.wikipedia.org/wiki/Bcrypt https://en.wikipedia.org/wiki/Bcrypt
        birken 13y ago
        I don't know exactly what situation you are trying to avoid, but with the standard bcrypt, if somebody has the IP hash and a candidate's specific IP, they can positively match the two (something you specifically mention on your privacy page). One possible tweak is to continue using bcrypt and a salt, but instead shorten the hash output to something like 24 bits. This way it still cannot be so easily reversed or rainbow-tabled, and collisions still shouldn't be an active problem. However, it wont be possible to positively match a given IP to a hash, since multiple IPs will likely hash to a given output. Granted, if you have a candidate IP and it matches the output hash, there is a very high probability that it was the source IP, but it wouldn't be 100%.
        gunn 13y ago
        Good answer... It looks like it would take on the order of 7 CPU years to create a table of every used address, much less time to target an area or individual. I don't think this is an issue at all though, I was just curious.
        Sir_Cmpwn 13y ago
        Actually, the salting is an important detail. Those 7 CPU years would only create a table for one hash. That's how long it takes to brute force a single hash, not the entire space.
        13y ago
    - vinceguidry 13y ago
      I'm pretty sure he was joking.
- duiker101 13y ago
  can't you make it automatic, taking the news with rss and stop it if you get a warrant?
  - Sir_Cmpwn 13y ago
    Nope. If an adversary seizes our servers, we couldn't stop it from falsely reporting that all is well.
    - duiker101 13y ago
      If an adversary seizes your servers wouldn't you have bigger worries like getting them back or complaying with the warrant?
    - atlbeer 13y ago
      If you sign the request w/ a key that isn't present on your servers than it should be impossible for that to occur. Unless they seize the computer with the key as well
  - Wilya 13y ago
    That defeats the purpose. I think the whole point of a warrant canary is that you have to do something, every week/month, to confirm that you never had to obey a warrant. And (presumably, I don't think it has been tried in courts yet) a gag order can prevent you to speak about a warrant, but it can't force you to do anything, including actively saying that you didn't receive anything. If it's automated.. the gag order prevents you to stop it, so it might as well not be there.
mike-cardwell 13y ago
mike@glue:~$ wget -qO - https://mediacru.sh/transparency/warrant-canary.txt|gpg --verify gpg: Signature made Fri 08 Nov 2013 11:48:13 GMT using RSA key ID 5044F2FC gpg: BAD signature from "MediaCrush Administrators <admin@mediacru.sh>" mike@glue:~$
- jdiez17 13y ago
  That's not the signed warrant canary - the PGP signed message lives at https://mediacru.sh/transparency/warrant-canary.signed.txt https://mediacru.sh/transparency/warrant-canary.signed.txt. josemanueldiez@InfiniteImprobabilityDrive:~$ wget -qO - https://mediacru.sh/transparency/warrant-canary.signed.txt|gpg --verify gpg: Signature made Fri Nov 8 12:48:13 2013 CET using RSA key ID 5044F2FC gpg: Good signature from "MediaCrush Administrators <admin@mediacru.sh>"
  - deleted 13y ago
    [deleted]
jdiez17 13y ago
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 This is a reply to a comment posted by graue on 2013/11/21 at 06:00h GMT. > Hmm... did this site get served a secret warrant last week? Or did they just forget to update their warrant canary? > https://mediacru.sh/transparency/warrant-canary.txt > (Note: the date 08/11 is written European style meaning November 8th, as you can see if you go up a directory.) Hi, just wanted to let you know that we haven't, in fact, been served a warrant. The failure to update the canary was due to my own mistake, and I'm terribly sorry about that. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.14 (GNU/Linux) iQIcBAEBAgAGBQJSjdtLAAoJELJF4ERQRPL8VuMP/j8bqNm/uAMzq1n+ebf90RRq cDQUsjCbENoR3/1VF4GR0iQhzxDQ28C2Wcc/rjgPjNkL5fLL9QQNb5hUZ38a+ray r3fBE4ZQZ5XSriq9iOGy2RoXKhwM/1QuJ9qaOOYmJwkc+/Re+1WbAtAbKnBoPkOy z5xMkSnr7b1jI/sUHHmlU6s5wvchXKKLmniCKjtaLp2WLVv95FoxrzRoNu/gHVv2 LXnjKTllzfcPm9thvCRoikv/N3PKuDBvCIbGm6yhYsNo8a1croAlnChEf0rDWk1B 8IFM5SXcsuVOSymHJ18VVp2s7xGi1RRcTpUyDt/s74kUuLx7Wpd27YWf5Yko8O+m BWfLXbAUamxwRyCmNN219xnhdAb0paaiddbvQX+PHUMMM2+UwdWSSgWnyloFVhGs bqZ/vQO6FSP4CVCZvvxyFm493MWSBTvZ2bpWWgdVdIBAg/qSv+D0I6XGyAhUdCqh 5j38U7nMaHFROr+lCISXdtMxUvPBzNFxKV+3ZTxm/L3hWU75pT9XWsJOxejiIdFe 7IMgKpbwsWDUg5Mat5muhn13vBH9B5qfa1smhO1eiP/29XLogLj3B2gZ0nnEIO0q 1o+j/G5crxxhqW01nGBzJq3IaP3+dsCP9Eiwom3cO0EsulZUL9TRsAPjT5IhXJNz uPzRgvYpICnrL2qqyGfP =uKWu -----END PGP SIGNATURE-----
- jqueryin 13y ago
  Speaking of warrant canaries, has anybody open sourced one to produce something similar with PGP and news? http://www.rsync.net/resources/notices/canary.txt http://www.rsync.net/resources/notices/canary.txt http://en.wikipedia.org/wiki/Warrant_canary http://en.wikipedia.org/wiki/Warrant_canary

by graue 13y ago

Sir_Cmpwn 13y ago

Ack! My other half is responsible for the warrant canary. He keeps forgetting it. We may as well not even have it. It doesn't mean much without a signature, but I assure you that we have never been served a warrant.

laureny 13y ago
Nice try, NSA.
- Sir_Cmpwn 13y ago
  Well, even if we had been served a warrant, I dunno what we'd give them. We don't store anything about our users. https://blog.mediacru.sh/2013/07/19/MediaCrush-for-nerds.html https://blog.mediacru.sh/2013/07/19/MediaCrush-for-nerds.htm...
  - deleted 13y ago
    [deleted]
    - Sir_Cmpwn 13y ago
      How do I word it? As of November 11th, 2013, neither MediaCrush nor its admins have ever received any sort of warrant, or any other kind of notice or request, from the government of any country. Additionally, we do not store anything about a user who visits our site. Here's an example from the HTTP log: [21/Nov/2013:06:59:36 +0000] "GET /static/favicon.ico HTTP/1.1" 200 16958 "-" 0.000 When you upload a file, your IP address is run though bcrypt (12 rounds) and saved with the file information in redis. Reversing bcrypt is infeasible with modern technology (and probably for many years to come). We store nothing else about you.
      - gunn 13y ago
        Is there a reason a complete IP address rainbow-table wouldn't defeat this?
        Sir_Cmpwn 13y ago
        bcrypt is designed to thwart rainbow-table attacks. It salts the hashes and it takes a while (1/3 of a second on my machine) to compute a single hash. https://en.wikipedia.org/wiki/Bcrypt https://en.wikipedia.org/wiki/Bcrypt
        birken 13y ago
        I don't know exactly what situation you are trying to avoid, but with the standard bcrypt, if somebody has the IP hash and a candidate's specific IP, they can positively match the two (something you specifically mention on your privacy page). One possible tweak is to continue using bcrypt and a salt, but instead shorten the hash output to something like 24 bits. This way it still cannot be so easily reversed or rainbow-tabled, and collisions still shouldn't be an active problem. However, it wont be possible to positively match a given IP to a hash, since multiple IPs will likely hash to a given output. Granted, if you have a candidate IP and it matches the output hash, there is a very high probability that it was the source IP, but it wouldn't be 100%.
        gunn 13y ago
        Good answer... It looks like it would take on the order of 7 CPU years to create a table of every used address, much less time to target an area or individual. I don't think this is an issue at all though, I was just curious.
        Sir_Cmpwn 13y ago
        Actually, the salting is an important detail. Those 7 CPU years would only create a table for one hash. That's how long it takes to brute force a single hash, not the entire space.
        13y ago
  - vinceguidry 13y ago
    I'm pretty sure he was joking.
duiker101 13y ago
can't you make it automatic, taking the news with rss and stop it if you get a warrant?
- Sir_Cmpwn 13y ago
  Nope. If an adversary seizes our servers, we couldn't stop it from falsely reporting that all is well.
  - duiker101 13y ago
    If an adversary seizes your servers wouldn't you have bigger worries like getting them back or complaying with the warrant?
  - atlbeer 13y ago
    If you sign the request w/ a key that isn't present on your servers than it should be impossible for that to occur. Unless they seize the computer with the key as well
- Wilya 13y ago
  That defeats the purpose. I think the whole point of a warrant canary is that you have to do something, every week/month, to confirm that you never had to obey a warrant. And (presumably, I don't think it has been tried in courts yet) a gag order can prevent you to speak about a warrant, but it can't force you to do anything, including actively saying that you didn't receive anything. If it's automated.. the gag order prevents you to stop it, so it might as well not be there.

mike-cardwell 13y ago

mike@glue:~$ wget -qO - https://mediacru.sh/transparency/warrant-canary.txt|gpg --verify gpg: Signature made Fri 08 Nov 2013 11:48:13 GMT using RSA key ID 5044F2FC gpg: BAD signature from "MediaCrush Administrators <admin@mediacru.sh>" mike@glue:~$

jdiez17 13y ago
That's not the signed warrant canary - the PGP signed message lives at https://mediacru.sh/transparency/warrant-canary.signed.txt https://mediacru.sh/transparency/warrant-canary.signed.txt. josemanueldiez@InfiniteImprobabilityDrive:~$ wget -qO - https://mediacru.sh/transparency/warrant-canary.signed.txt|gpg --verify gpg: Signature made Fri Nov 8 12:48:13 2013 CET using RSA key ID 5044F2FC gpg: Good signature from "MediaCrush Administrators <admin@mediacru.sh>"
- deleted 13y ago
  [deleted]

jdiez17 13y ago

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 This is a reply to a comment posted by graue on 2013/11/21 at 06:00h GMT. > Hmm... did this site get served a secret warrant last week? Or did they just forget to update their warrant canary? > https://mediacru.sh/transparency/warrant-canary.txt > (Note: the date 08/11 is written European style meaning November 8th, as you can see if you go up a directory.) Hi, just wanted to let you know that we haven't, in fact, been served a warrant. The failure to update the canary was due to my own mistake, and I'm terribly sorry about that. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.14 (GNU/Linux) iQIcBAEBAgAGBQJSjdtLAAoJELJF4ERQRPL8VuMP/j8bqNm/uAMzq1n+ebf90RRq cDQUsjCbENoR3/1VF4GR0iQhzxDQ28C2Wcc/rjgPjNkL5fLL9QQNb5hUZ38a+ray r3fBE4ZQZ5XSriq9iOGy2RoXKhwM/1QuJ9qaOOYmJwkc+/Re+1WbAtAbKnBoPkOy z5xMkSnr7b1jI/sUHHmlU6s5wvchXKKLmniCKjtaLp2WLVv95FoxrzRoNu/gHVv2 LXnjKTllzfcPm9thvCRoikv/N3PKuDBvCIbGm6yhYsNo8a1croAlnChEf0rDWk1B 8IFM5SXcsuVOSymHJ18VVp2s7xGi1RRcTpUyDt/s74kUuLx7Wpd27YWf5Yko8O+m BWfLXbAUamxwRyCmNN219xnhdAb0paaiddbvQX+PHUMMM2+UwdWSSgWnyloFVhGs bqZ/vQO6FSP4CVCZvvxyFm493MWSBTvZ2bpWWgdVdIBAg/qSv+D0I6XGyAhUdCqh 5j38U7nMaHFROr+lCISXdtMxUvPBzNFxKV+3ZTxm/L3hWU75pT9XWsJOxejiIdFe 7IMgKpbwsWDUg5Mat5muhn13vBH9B5qfa1smhO1eiP/29XLogLj3B2gZ0nnEIO0q 1o+j/G5crxxhqW01nGBzJq3IaP3+dsCP9Eiwom3cO0EsulZUL9TRsAPjT5IhXJNz uPzRgvYpICnrL2qqyGfP =uKWu -----END PGP SIGNATURE-----

jqueryin 13y ago
Speaking of warrant canaries, has anybody open sourced one to produce something similar with PGP and news? http://www.rsync.net/resources/notices/canary.txt http://www.rsync.net/resources/notices/canary.txt http://en.wikipedia.org/wiki/Warrant_canary http://en.wikipedia.org/wiki/Warrant_canary