3 ms·

Careful with their encryption: http://crypto.junod.info/2012/05/24/owncloud-4-0-and-encryption/ http://crypto.junod.info/2012/05/24/owncloud-4-0-and-encrypt...

conformal 14y ago
had a good laugh when i saw this article. thx mithrandir :) passwords stored in the clear in server-side sessions => server hack compromises data. storing keys server-side means admins can get into your data. had a big lol at the use of blowfish ECB - use of any cipher's ECB mode for bulk encryption is asking for problems. they should be using CBC, CTR, LRW or, ideally, XTS modes.
- graue 14y ago
  Using server-side encryption at all means admins can get into your data, does it not? They can modify the source code so that when the server decrypts/encrypts the data at your request, it also saves a copy in cleartext. How would you avoid this without encrypting on the client side?
graue 14y ago
Summary of the link: OwnCloud is using Mersenne Twister (not secure) seeded by time of day and PID (which is not nearly enough entropy) to generate keys. The encryption is done in ECB mode, which leaks data (https://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Electronic_codebook_.28ECB.29 https://en.wikipedia.org/wiki/Block_cipher_modes_of_operatio...). The encryption key is stored in the clear in session data, which usually resides in /tmp. There's more, but those seem to be the worst parts.
- DenisM 14y ago
  Thank you for the useful summary. I wish more people did that.
kijin 14y ago
Oh Gawd. I would have thought that someone who claims to be in the business of making a more secure alternative Dropbox would actually know something about how to encrypt things. Also, what's the benefit of using a 7-year-old pure-PHP implementation of Blowfish when mcrypt gets the job done much better and faster? OwnCloud's install instructions actually require a bunch of PHP extensions. They could have just thrown mcrypt into that list.

conformal 14y ago

had a good laugh when i saw this article. thx mithrandir :) passwords stored in the clear in server-side sessions => server hack compromises data. storing keys server-side means admins can get into your data. had a big lol at the use of blowfish ECB - use of any cipher's ECB mode for bulk encryption is asking for problems. they should be using CBC, CTR, LRW or, ideally, XTS modes.

graue 14y ago
Using server-side encryption at all means admins can get into your data, does it not? They can modify the source code so that when the server decrypts/encrypts the data at your request, it also saves a copy in cleartext. How would you avoid this without encrypting on the client side?

graue 14y ago

Summary of the link: OwnCloud is using Mersenne Twister (not secure) seeded by time of day and PID (which is not nearly enough entropy) to generate keys. The encryption is done in ECB mode, which leaks data (https://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Electronic_codebook_.28ECB.29 https://en.wikipedia.org/wiki/Block_cipher_modes_of_operatio...). The encryption key is stored in the clear in session data, which usually resides in /tmp. There's more, but those seem to be the worst parts.

DenisM 14y ago
Thank you for the useful summary. I wish more people did that.

kijin 14y ago

Oh Gawd. I would have thought that someone who claims to be in the business of making a more secure alternative Dropbox would actually know something about how to encrypt things. Also, what's the benefit of using a 7-year-old pure-PHP implementation of Blowfish when mcrypt gets the job done much better and faster? OwnCloud's install instructions actually require a bunch of PHP extensions. They could have just thrown mcrypt into that list.