I am trying to connect to a new Minecraft server I own (from a client I own as well). This is a brand new Ubuntu 18.04 installation with Java 10 and the latest Minecraft 1.12 server.
During the connection, the JRE is establishing a connection to authentication servers and the whole connection ends (from the Minecraft server perspective) with a
[09:06:57] [User Authenticator #4/ERROR]: Couldn't verify username because servers are unavailable
[09:06:57] [Server thread/INFO]: com.mojang.authlib.GameProfile@949cab4d[id=<null>,name=TheNameOfTheUser,properties={},legacy=false] (/10.1.1.19: 41433) lost connection: Authentication servers are down. Please try again later, sorry!
The authentication servers certainly not being down, I traced the connection and see in a network dump
No. Time Source Destination Protocol Length Info
98 3.254294 10.200.0.133 54.230.198.91 TCP 74 43370 → 443 [SYN] Seq=0 Win=29200 Len=0 MSS=1460 SACK_PERM=1 TSval=1994960819 TSecr=0 WS=128
No. Time Source Destination Protocol Length Info
99 3.265065 54.230.198.91 10.200.0.133 TCP 74 443 → 43370 [SYN, ACK] Seq=0 Ack=1 Win=28960 Len=0 MSS=1460 SACK_PERM=1 TSval=1446415026 TSecr=1994960819 WS=256
No. Time Source Destination Protocol Length Info
100 3.265079 10.200.0.133 54.230.198.91 TCP 66 43370 → 443 [ACK] Seq=1 Ack=1 Win=29312 Len=0 TSval=1994960830 TSecr=1446415026
No. Time Source Destination Protocol Length Info
101 3.266259 10.200.0.133 54.230.198.91 TLSv1.2 342 Client Hello
No. Time Source Destination Protocol Length Info
102 3.275952 54.230.198.91 10.200.0.133 TCP 66 443 → 43370 [ACK] Seq=1 Ack=277 Win=30208 Len=0 TSval=1446415027 TSecr=1994960831
No. Time Source Destination Protocol Length Info
103 3.279589 54.230.198.91 10.200.0.133 TLSv1.2 5538 Server Hello, Certificate, Certificate Status, Server Key Exchange, Server Hello Done
Frame 103: 5538 bytes on wire (44304 bits), 5538 bytes captured (44304 bits)
Ethernet II, Src: 12:5b:d3:1d:51:cf (12:5b:d3:1d:51:cf), Dst: d6:8b:35:0c:a2:f2 (d6:8b:35:0c:a2:f2)
Internet Protocol Version 4, Src: 54.230.198.91, Dst: 10.200.0.133
Transmission Control Protocol, Src Port: 443, Dst Port: 43370, Seq: 1, Ack: 277, Len: 5472
Secure Sockets Layer
TLSv1.2 Record Layer: Handshake Protocol: Server Hello
Content Type: Handshake (22)
Version: TLS 1.2 (0x0303)
Length: 65
Handshake Protocol: Server Hello
TLSv1.2 Record Layer: Handshake Protocol: Certificate
Content Type: Handshake (22)
Version: TLS 1.2 (0x0303)
Length: 4566
Handshake Protocol: Certificate
TLSv1.2 Record Layer: Handshake Protocol: Certificate Status
Content Type: Handshake (22)
Version: TLS 1.2 (0x0303)
Length: 479
Handshake Protocol: Certificate Status
TLSv1.2 Record Layer: Handshake Protocol: Server Key Exchange
Content Type: Handshake (22)
Version: TLS 1.2 (0x0303)
Length: 333
Handshake Protocol: Server Key Exchange
TLSv1.2 Record Layer: Handshake Protocol: Server Hello Done
Content Type: Handshake (22)
Version: TLS 1.2 (0x0303)
Length: 4
Handshake Protocol: Server Hello Done
No. Time Source Destination Protocol Length Info
104 3.279602 10.200.0.133 54.230.198.91 TCP 66 43370 → 443 [ACK] Seq=277 Ack=5473 Win=40192 Len=0 TSval=1994960844 TSecr=1446415028
Frame 104: 66 bytes on wire (528 bits), 66 bytes captured (528 bits)
Ethernet II, Src: d6:8b:35:0c:a2:f2 (d6:8b:35:0c:a2:f2), Dst: 12:5b:d3:1d:51:cf (12:5b:d3:1d:51:cf)
Internet Protocol Version 4, Src: 10.200.0.133, Dst: 54.230.198.91
Transmission Control Protocol, Src Port: 43370, Dst Port: 443, Seq: 277, Ack: 5473, Len: 0
No. Time Source Destination Protocol Length Info
105 3.280246 10.200.0.133 54.230.198.91 TLSv1.2 73 Alert (Level: Fatal, Description: Internal Error)
Frame 105: 73 bytes on wire (584 bits), 73 bytes captured (584 bits)
Ethernet II, Src: d6:8b:35:0c:a2:f2 (d6:8b:35:0c:a2:f2), Dst: 12:5b:d3:1d:51:cf (12:5b:d3:1d:51:cf)
Internet Protocol Version 4, Src: 10.200.0.133, Dst: 54.230.198.91
Transmission Control Protocol, Src Port: 43370, Dst Port: 443, Seq: 277, Ack: 5473, Len: 7
Secure Sockets Layer
TLSv1.2 Record Layer: Alert (Level: Fatal, Description: Internal Error)
Content Type: Alert (21)
Version: TLS 1.2 (0x0303)
Length: 2
Alert Message
Level: Fatal (2)
Description: Internal Error (80)
No. Time Source Destination Protocol Length Info
106 3.280277 10.200.0.133 54.230.198.91 TCP 66 43370 → 443 [FIN, ACK] Seq=284 Ack=5473 Win=40192 Len=0 TSval=1994960845 TSecr=1446415028
Frame 106: 66 bytes on wire (528 bits), 66 bytes captured (528 bits)
Ethernet II, Src: d6:8b:35:0c:a2:f2 (d6:8b:35:0c:a2:f2), Dst: 12:5b:d3:1d:51:cf (12:5b:d3:1d:51:cf)
Internet Protocol Version 4, Src: 10.200.0.133, Dst: 54.230.198.91
Transmission Control Protocol, Src Port: 43370, Dst Port: 443, Seq: 284, Ack: 5473, Len: 0
No. Time Source Destination Protocol Length Info
112 3.290075 54.230.198.91 10.200.0.133 TCP 66 443 → 43370 [FIN, ACK] Seq=5473 Ack=285 Win=30208 Len=0 TSval=1446415029 TSecr=1994960845
Frame 112: 66 bytes on wire (528 bits), 66 bytes captured (528 bits)
Ethernet II, Src: 12:5b:d3:1d:51:cf (12:5b:d3:1d:51:cf), Dst: d6:8b:35:0c:a2:f2 (d6:8b:35:0c:a2:f2)
Internet Protocol Version 4, Src: 54.230.198.91, Dst: 10.200.0.133
Transmission Control Protocol, Src Port: 443, Dst Port: 43370, Seq: 5473, Ack: 285, Len: 0
No. Time Source Destination Protocol Length Info
113 3.290088 10.200.0.133 54.230.198.91 TCP 66 43370 → 443 [ACK] Seq=285 Ack=5474 Win=40192 Len=0 TSval=1994960855 TSecr=1446415029
Frame 113: 66 bytes on wire (528 bits), 66 bytes captured (528 bits)
Ethernet II, Src: d6:8b:35:0c:a2:f2 (d6:8b:35:0c:a2:f2), Dst: 12:5b:d3:1d:51:cf (12:5b:d3:1d:51:cf)
Internet Protocol Version 4, Src: 10.200.0.133, Dst: 54.230.198.91
Transmission Control Protocol, Src Port: 43370, Dst Port: 443, Seq: 285, Ack: 5474, Len: 0
Problems are on frame 105, where an Internal Error happens. Since the game is in Java, I assume that this is liked with the Java TLS implementation and this "Internal Error" may actually mean something more?
I reinstalled the Java certificates (update-ca-certificates -f) as one of the possible causes, but no luck.
