2

According to wikipedia or https://www.us-cert.gov/ncas/alerts/TA14-290A

this is an issue with the SSL v3.0 non deterministic padding used in CBC. Is AES in CBC mode itself is un-secure or it is an issue only when used in SSLv3.0/TLS ? Can you please clarify ?

I use openssl (an old version before the poodle attack fix) aes-128-cbc mode to encrypt a file like below, openssl enc -aes-128-cbc -in test -out test.enc -K $key128 -iv $iv

Is test.enc secure as far as the poodle attack/padding oracle attack is concerned ? If not secure, how can I make it secure ? will patching openssl to the new version take care ?

Thanks

  • The problem can be with (mostly) unchecked padding plus an oracle, in any cipher and mode that uses padding. SSL/TLS does not have any modes that pad other than CBC, but it does have ciphers other than AES that operate in CBC with padding. enc with a block-mode cipher uses PKCS#5/7 padding which is checked. – dave_thompson_085 Jan 28 '15 at 11:37
1

POODLE requires a MITM component to be successful. You need to have a long enough stream of cyphertexts before you are able to decypher the stream. Encrypting a single file does not expose MITM vectors.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.