openvpn ATTENZIONE: nessun metodo di verifica del certificato del server è stato abilitato

Ho provato a installare openvpn su debian squeez (server) e connettermi dal mio fedora 17 come (client). Ecco la mia configurazione:

configurazione del server

# Server TCP
proto tcp
port 1194
dev tun

# Keys and certificates
ca /etc/openvpn/easy-rsa/keys/ca.crt
cert /etc/openvpn/easy-rsa/keys/server.crt
key /etc/openvpn/easy-rsa/keys/server.key
dh /etc/openvpn/easy-rsa/keys/dh1024.pem

# Network
# Virtual address of the VPN network
server 192.170.70.0 255.255.255.0
# This line adds the client to the router network server
push "route 192.168.1.0 255.255.255.0"
# Create a route server to the tun interface
#route 192.170.70.0 255.255.255.0

# Security
keepalive 10 120
# type of data encryption
cipher AES-128-CBC
# enabling compression
comp-lzo
# maximum number of clients allowed
max-clients 10
# no user and group specific to the use of the VPN
user nobody
group nogroup

# to make persistent connection
persist-key
persist-tun

# Log of the OpenVPN status
status /var/log/openvpn-status.log

# logs openvpnlog /var/log/openvpn.log
log-append /var/log/openvpn.log

# verbosity
verb 5

configurazione client

client
dev tun
proto tcp-client
remote <my server wan IP> 1194
resolv-retry infinite
cipher AES-128-CBC

# Keys
ca ca.crt
cert client.crt
key client.key

# Security
nobind
persist-key
persist-tun
comp-lzo
verb 3

Messaggio dal client host (fedora 17) nel file di registro /var/log/messages:

Dec  6 21:56:00 GlobalTIC NetworkManager[691]: <info> Starting VPN service 'openvpn'...
Dec  6 21:56:00 GlobalTIC NetworkManager[691]: <info> VPN service 'openvpn' started (org.freedesktop.NetworkManager.openvpn), PID 7470
Dec  6 21:56:00 GlobalTIC NetworkManager[691]: <info> VPN service 'openvpn' appeared; activating connections
Dec  6 21:56:00 GlobalTIC NetworkManager[691]: <info> VPN plugin state changed: starting (3)
Dec  6 21:56:01 GlobalTIC NetworkManager[691]: <info> VPN connection 'Connexion VPN 1' (Connect) reply received.
Dec  6 21:56:01 GlobalTIC nm-openvpn[7472]: OpenVPN 2.2.2 x86_64-redhat-linux-gnu [SSL] [LZO2] [EPOLL] [PKCS11] [eurephia] built on Sep  5 2012
Dec  6 21:56:01 GlobalTIC nm-openvpn[7472]:[COLOR="Red"][U][B] WARNING: No server certificate verification method has been enabled.[/B][/U][/COLOR]  See http://openvpn.net/howto.html#mitm for more info.
Dec  6 21:56:01 GlobalTIC nm-openvpn[7472]: NOTE: the current --script-security setting may allow this configuration to call user-defined scripts
Dec  6 21:56:01 GlobalTIC nm-openvpn[7472]:[COLOR="Red"] WARNING: file '/home/login/client/client.key' is group or others accessible[/COLOR]
Dec  6 21:56:01 GlobalTIC nm-openvpn[7472]: UDPv4 link local: [undef]
Dec  6 21:56:01 GlobalTIC nm-openvpn[7472]: UDPv4 link remote: [COLOR="Red"]<my server wan IP>[/COLOR]:1194
Dec  6 21:56:01 GlobalTIC nm-openvpn[7472]: [COLOR="Red"]read UDPv4 [ECONNREFUSED]: Connection refused (code=111)[/COLOR]
Dec  6 21:56:03 GlobalTIC nm-openvpn[7472]: [COLOR="Red"]read UDPv4[/COLOR] [ECONNREFUSED]: Connection refused (code=111)
Dec  6 21:56:07 GlobalTIC nm-openvpn[7472]: read UDPv4 [ECONNREFUSED]: Connection refused (code=111)
Dec  6 21:56:15 GlobalTIC nm-openvpn[7472]: read UDPv4 [ECONNREFUSED]: Connection refused (code=111)
Dec  6 21:56:31 GlobalTIC nm-openvpn[7472]: read UDPv4 [ECONNREFUSED]: Connection refused (code=111)
Dec  6 21:56:41 GlobalTIC NetworkManager[691]: <warn> VPN connection 'Connexion VPN 1' (IP Conf[/CODE]

ifconfig sull'host server (debian):

ifconfig 
eth0      Link encap:Ethernet  HWaddr 08:00:27:16:21:ac  
          inet addr:192.168.1.6  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::a00:27ff:fe16:21ac/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:9059 errors:0 dropped:0 overruns:0 frame:0
          TX packets:5660 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:919427 (897.8 KiB)  TX bytes:1273891 (1.2 MiB)
tun0      Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  
          inet addr:192.170.70.1  P-t-P:192.170.70.2  Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

ifconfig sull'host client (fedora 17)

as0t0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1500
        inet 5.5.0.1  netmask 255.255.252.0  destination 5.5.0.1
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 200  (UNSPEC)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2  bytes 321 (321.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

as0t1: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1500
        inet 5.5.4.1  netmask 255.255.252.0  destination 5.5.4.1
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 200  (UNSPEC)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2  bytes 321 (321.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

as0t2: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1500
        inet 5.5.8.1  netmask 255.255.252.0  destination 5.5.8.1
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 200  (UNSPEC)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2  bytes 321 (321.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

as0t3: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1500
        inet 5.5.12.1  netmask 255.255.252.0  destination 5.5.12.1
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 200  (UNSPEC)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2  bytes 321 (321.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

**p255p1**: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.2  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::21d:baff:fe20:b7e6  prefixlen 64  scopeid 0x20<link>
        ether 00:1d:ba:20:b7:e6  txqueuelen 1000  (Ethernet)
        RX packets 4842070  bytes 3579798184 (3.3 GiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 3996158  bytes 2436442882 (2.2 GiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device interrupt 16  

p255p1 è un'etichetta per l'interfaccia eth0

e

sul server:

root@hoteserver:/etc/openvpn# tree
.
├── client
│** ├── ca.crt
│** ├── client.conf
│** ├── client.crt
│** ├── client.csr
│** ├── client.key
│** ├── client.ovpn
│*
│** 
├── easy-rsa
│** ├── build-ca
│** ├── build-dh
│** ├── build-inter
│** ├── build-key
│** ├── build-key-pass
│** ├── build-key-pkcs12
│** ├── build-key-server
│** ├── build-req
│** ├── build-req-pass
│** ├── clean-all
│** ├── inherit-inter
│** ├── keys
│** │** ├── 01.pem
│** │** ├── 02.pem
│** │** ├── ca.crt
│** │** ├── ca.key
│** │** ├── client.crt
│** │** ├── client.csr
│** │** ├── client.key
│** │** ├── dh1024.pem
│** │** ├── index.txt
│** │** ├── index.txt.attr
│** │** ├── index.txt.attr.old
│** │** ├── index.txt.old
│** │** ├── serial
│** │** ├── serial.old
│** │** ├── server.crt
│** │** ├── server.csr
│** │** └── server.key
│** ├── list-crl
│** ├── Makefile
│** ├── openssl-0.9.6.cnf.gz
│** ├── openssl.cnf
│** ├── pkitool
│** ├── README.gz
│** ├── revoke-full
│** ├── sign-req
│** ├── vars
│** └── whichopensslcnf
├── openvpn.log
├── openvpn-status.log
├── server.conf
└── update-resolv-conf

sul cliente:

[login@hoteclient openvpn]$ tree 
.
|-- easy-rsa
|   |-- 1.0
|   |   |-- build-ca
|   |   |-- build-dh
|   |   |-- build-inter
|   |   |-- build-key
|   |   |-- build-key-pass
|   |   |-- build-key-pkcs12
|   |   |-- build-key-server
|   |   |-- build-req
|   |   |-- build-req-pass
|   |   |-- clean-all
|   |   |-- list-crl
|   |   |-- make-crl
|   |   |-- openssl.cnf
|   |   |-- README
|   |   |-- revoke-crt
|   |   |-- revoke-full
|   |   |-- sign-req
|   |   `-- vars
|   `-- 2.0
|       |-- build-ca
|       |-- build-dh
|       |-- build-inter
|       |-- build-key
|       |-- build-key-pass
|       |-- build-key-pkcs12
|       |-- build-key-server
|       |-- build-req
|       |-- build-req-pass
|       |-- clean-all
|       |-- inherit-inter
|       |-- keys [error opening dir]
|       |-- list-crl
|       |-- Makefile
|       |-- openssl-0.9.6.cnf
|       |-- openssl-0.9.8.cnf
|       |-- openssl-1.0.0.cnf
|       |-- pkitool
|       |-- README
|       |-- revoke-full
|       |-- sign-req
|       |-- vars
|       `-- whichopensslcnf
|-- keys -> ./easy-rsa/2.0/keys/
`-- server.conf

L'origine del problema cipher AES-128-CBC, proto tcp-cliento UDP o l'interfaccia p255p1su Fedora17 o l'autenticazione del file ta.keynon è stata trovata?

Innanzitutto è necessario modificare le autorizzazioni sul /home/login/client/client.keyfile in modo che non siano accessibili a gruppi o ad altri.

chmod 400 /home/login/client/client.key

Quindi, come descritto qui, è necessario implementare un metodo per verificare che i client si connettano al server corretto e che non sia possibile alcun attacco man-in-middle.

C'è un elenco completo di problemi qui e dovresti prendere sul serio le avvertenze fornite da OpenVPN. Ma ci sono solo avvisi e non il motivo del tuo problema per ottenere una connessione. Il plug-in openvpn di NetworkManager sta tentando di connettersi tramite UDP. Non so quale relazione abbia il tuo client.conf con la tua attuale configurazione client. È stato utilizzato per importare le impostazioni VPN in NetworkManager?
In ogni caso, devi selezionare la casella di controllo Connessione TCP nella finestra di dialogo delle impostazioni avanzate del tuo profilo di connessione VPN.
Dato che non sembra che usi tls-auth né sul client né sul lato server, non dovrebbe mancare il file ta.key (ma usare tls-auth è una buona idea).
Il codice sembra essere lo stesso su entrambi i lati e non dovrebbe essere un problema.
Ho davvero consigliamo vivamente averifica il certificato del server , come indicato da morlix.

Per eliminare l' No server certificate verification method has been enabledavviso, genera i certificati client e server con l' extendedKeyUsageestensione corretta e aggiungi quelli remote-cert-tls serverdel client openvpn.conf.

Aggiungi due sezioni alle CA openssl.cnf:

[server_cert]
basicConstraints = CA:FALSE
nsCertType = server
nsComment = "OpenSSL Generated Server Certificate"
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid,issuer:always
keyUsage = critical, digitalSignature, keyEncipherment
extendedKeyUsage = serverAuth

[client_cert]
basicConstraints = CA:FALSE
nsCertType = client, email
nsComment = "OpenSSL Generated Client Certificate"
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid,issuer
keyUsage = critical, nonRepudiation, digitalSignature, keyEncipherment
extendedKeyUsage = clientAuth, emailProtection

Firma i certificati del server nella tua CA in questo modo:

openssl ca -config openssl.cnf -extensions server_cert -notext -md sha256 -in csr.pem -out cert.pem

Firma i certificati dei clienti in questo modo:

openssl ca -config openssl.cnf -extensions client_cert -notext -md sha256 -in csr.pem -out cert.pem

Quindi, nel tuo client, openvpn.cnfaggiungi la seguente riga:

remote-cert-tls server

e riavviare il servizio openvpn.