HackTheBoxにてopenvpnでマシンに接続できない時の対処法

マシンの接続方法で"OpenVPN"を選んだ後、ProtocolをUDPにしてもTCPにしても

# openvpn lab_hoge.ovpn

を実行した際に以下の様なエラーが出続けた。

2022-11-23 12:01:22 Outgoing Control Channel Authentication: Using 256 bit message hash 'SHA256' for HMAC authentication
2022-11-23 12:01:22 Incoming Control Channel Authentication: Using 256 bit message hash 'SHA256' for HMAC authentication
2022-11-23 12:01:22 TCP/UDP: Preserving recently used remote address: [AF_INET]23.106.59.94:1337
2022-11-23 12:01:22 Socket Buffers: R=[212992->212992] S=[212992->212992]
2022-11-23 12:01:22 UDP link local: (not bound)
2022-11-23 12:01:22 UDP link remote: [AF_INET]23.106.59.94:1337
2022-11-23 12:01:22 TLS: Initial packet from [AF_INET]23.106.59.94:1337, sid=b0f93406 a51c096f
2022-11-23 12:01:22 VERIFY ERROR: depth=0, error=CA signature digest algorithm too weak: C=UK, ST=City, L=London, O=HackTheBox, CN=htb, name=htb, emailAddress=info@hackthebox.eu, serial=1
2022-11-23 12:01:22 OpenSSL: error:0A000086:SSL routines::certificate verify failed
2022-11-23 12:01:22 TLS_ERROR: BIO read tls_read_plaintext error
2022-11-23 12:01:22 TLS Error: TLS object -> incoming plaintext read error
2022-11-23 12:01:22 TLS Error: TLS handshake failed
2022-11-23 12:01:22 SIGUSR1[soft,tls-error] received, process restarting
2022-11-23 12:01:22 Restart pause, 5 second(s)

解決策としては、SERVERを別の場所（自分の場合はASIA Free → US FREE）にすると直った。