Bug#877721: racoon: IPsec tunnel with HMAC SHA256 in phase 2 is not working correctly

[Bartek Krawczyk]

And below you see a working strongSwan configuration with HMAC SHA256 
tested on the same server also on Debian stretch with the same PSK

conn VPN
        left=217.182.74.61
        leftsubnet=4.4.4.4/32[gre]
        rightsubnet=2.2.2.2/32[gre]
        rightauth=psk
        leftauth=psk
        authby=psk
        auto=add
        dpdaction=restart
        dpddelay=30s
        dpdtimeout=120s
        ike=aes128-sha256-modp3072!
        esp=aes128-sha256-modp3072!
        ikelifetime=24h
        lifetime=4h
        installpolicy=yes
        keyexchange=ikev1
        type=tunnel

Regards
Bartek Krawczyk