Re: Decrypting data in RX path

[Stephan Mueller <smueller@chronox.de>]

Am Montag, 16. Mai 2016, 17:24:12 schrieb Gadre Nayan:

Hi Gadre,

> Hi,
> 
> I am able to encrypt data using the asynchronous kernel crypto API's.
> I can observe the encrypted data on the protocol analyzer.
> 
> I wanted to decry-pt the data now on the receiver side, So I have
> following questions.
> 
> 1. What is the best place to decrypt the data, in kernel space (module
> (pre-routing hook) or driver) OR user space using (maybe using raw
> sockets or after socket recv).

This is a very broad question and cannot be answered without knowning the 
context.
> 
> What precautions should be taken in terms of locking while using
> crypto api's in kernel space in RX path (Softirq context) --> Can
> someone point to existing sample in kernel where decryption is done in
> RX path.

net/ipv4/esp4.c:esp_input for rx and esp_output for tx.
> 
> 
> 2. If I encrypt data in kernel space can I decrypt it in User-space
> using same encryption methods and Keys.

Sure, if you have the keys and all information about the used crypto.
> 
> Thanks.
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Ciao
Stephan