Forum Discussion

IheartF5_45022's avatar
Sep 03, 2010

AES::encrypt - can decrypt function be carried out elsewhere?

If the F5 has used AES ecryption to encrypt a string via AES::encrypt, can the key be exported and used on another downstream device to decrypt? This downstream device could be



a) another F5


b) not an F5



I'm putting those 2 options there in case the answer is different for each.



The last devcentral posts I saw on this indicated that the encryption/decryption was intended to be carried out on the same device but that new information may be released soon. This was a year ago. Are there any updates?








3 Replies

  • Hamish's avatar
    Icon for Cirrocumulus rankCirrocumulus
    Another F5 device, yes certainly (You can prove that with an HA pair and a hard-coded or shared key. When an HA failover occurs, the backup device can now decrypt the content that the primary device encrypted)...



    A non-F5 device, SHOULD be possible, but I've never tried it...



    I suspect what you're trying to do though is to tunnel traffic across a network from one F5 to another? If so, why not simply use an SSL/TLS tunnel or connection?



  • As Hamish said, this is possible, as long as you use a hardcoded key. Do not use [AES::key] command, as this generates a random key and the same key must be used to encrypt or decrypt. This is due to AES being a symmetric key encryption algorithm, meaning both sides need to use a shared key.





    • patonbike's avatar
      Icon for Cirrus rankCirrus

      Does anyone know the syntax to decrypt data on say, a linux machine with openssl command? I am trying to do this as a proof of concept. Obviously we are using a pre shared key.

      What cipher is it?

      This does NOT work:


      openssl aes-256-ecb -d -K MY_AES_256_KEY_HERE base64 -in MY_F5_Base64_encoded_aes256_string_here.txt -debug