[strongSwan] SHA1 vs SHA256

[Dusan Ilic]

Hi Thomas,

I haven't upgraded it cause that's not an option, both endpoints are 
routers with Linux embedded.
Below is the output after some pings from both sides.

Strongswan 5.5.2

ip -s x s s
src 85.24.241.x dst 94.254.123.x
         proto esp spi 0xce291943(3458799939) reqid 1(0x00000001) mode 
tunnel
         replay-window 0 seq 0x00000000 flag nopmtudisc af-unspec 
(0x00100100)
         auth-trunc hmac(sha256) 
0xc45dd8403c10cfd32f8fe74003cc80a309b7a0decb185826ef62ac1763ae4bcd (256 
bits) 128
         enc cbc(aes) 
0x0abb9115383986028a844ff1e71bd0f55aa22099d76785b288803ed7204aa23e (256 
bits)
         lifetime config:
           limit: soft (INF)(bytes), hard (INF)(bytes)
           limit: soft (INF)(packets), hard (INF)(packets)
           expire add: soft 2762(sec), hard 3600(sec)
           expire use: soft 0(sec), hard 0(sec)
         lifetime current:
           1416(bytes), 25(packets)
           add 2017-08-06 20:08:26 use 2017-08-06 20:08:31
         stats:
           replay-window 0 replay 0 failed 0
src 94.254.123.x dst 85.24.241.x
         proto esp spi 0xc9359a4e(3375733326) reqid 1(0x00000001) mode 
tunnel
         replay-window 32 seq 0x00000000 flag nopmtudisc af-unspec 
(0x00100100)
         auth-trunc hmac(sha256) 
0xfe9408ba634fe4276972fa79c9b60f12bffc766434298cb25738396d2b94dda9 (256 
bits) 128
         enc cbc(aes) 
0x1fd6fd06781cee3bab6ed97a2f01793eded22f7360691430fdfb604c4e424066 (256 
bits)
         lifetime config:
           limit: soft (INF)(bytes), hard (INF)(bytes)
           limit: soft (INF)(packets), hard (INF)(packets)
           expire add: soft 2895(sec), hard 3600(sec)
           expire use: soft 0(sec), hard 0(sec)
         lifetime current:
           0(bytes), 0(packets)
           add 2017-08-06 20:08:26 use 2017-08-06 20:08:28
         stats:
           replay-window 0 replay 0 failed 49

Strongswan 5.2.2

ip -s x s s
src 94.254.123.x dst 85.24.241.x
         proto esp spi 0xc9359a4e(3375733326) reqid 1(0x00000001) mode 
tunnel

Den 2017-08-06 kl. 16:49, skrev Thomas Egerer:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA256
>
> Hello Dusan,
>
> if you haven't yet updated your kernel, we might shed some light on
> the problem. Set up the tunnel with SHA256 and send a couple of
> packets from both sides. Then provide the output of
> 'ip -s x s s'
>
> Cheers,
> Thomas
>
>
> On 08/04/2017 12:23 PM, Dusan Ilic wrote:
>> Hello!
>>
>> I have a strange issue, with both settings below the tunnel goes up as it should, but only with SHA1 in ESP traffic goes through. When I ping the remote client with ESP SHA256 it times out, even though the tunnel reports as being up by Strongswan.
>>
>> Traffic working:
>>
>> ike=aes256-sha256-modp2048!
>> esp=aes128-sha1-modp2048!
>>
>> Traffic not working:
>>
>> ike=aes256-sha256-modp2048!
>> esp=aes256-sha256-modp2048!
>>
>> Below combo doesn't work either:
>>
>> ike=aes256-sha256-modp2048!
>> esp=aes128-sha256-modp2048!
>>
>>
>> Also, are above settings good? I'm having AES128 on ESP because with AES256 I loose too much througput. Do you have any suggestions for change?
>>
>>
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