I was testing enabling TLS support on Pico HTTP server (using mbedtls_config.h from pico-examples), and noticed about 3 second delay during TLS handshake on incoming connections. Is this to be expected or is there perhaps some tricks that could be used to speed up the TLS handshake?
I noticed that curl was complaining about server not supporting ALPN, so I tried enabling that, but it didn't seem to have any effect on the TLS handshake speed...
Code:
1 0.000000000 192.168.1.40 → 192.168.4.221 TCP 74 45296 → 443 [SYN] Seq=0 Win=64240 Len=0 MSS=1460 SACK_PERM TSval=1271741520 TSecr=0 WS=128 2 0.105772747 192.168.4.221 → 192.168.1.40 TCP 60 443 → 45296 [SYN, ACK] Seq=0 Ack=1 Win=17520 Len=0 MSS=1460 3 0.105825030 192.168.1.40 → 192.168.4.221 TCP 54 45296 → 443 [ACK] Seq=1 Ack=1 Win=64240 Len=0 4 0.109828290 192.168.1.40 → 192.168.4.221 TLSv1 571 Client Hello 5 0.120327558 192.168.4.221 → 192.168.1.40 TLSv1.2 1201 Server Hello, Certificate, Certificate Request, Server Hello Done 6 0.120389604 192.168.1.40 → 192.168.4.221 TCP 54 45296 → 443 [ACK] Seq=518 Ack=1148 Win=63093 Len=0 7 0.122103775 192.168.1.40 → 192.168.4.221 TLSv1.2 384 Certificate, Client Key Exchange, Change Cipher Spec, Encrypted Handshake Message 8 0.450569223 192.168.1.40 → 192.168.4.221 TCP 384 [TCP Retransmission] 45296 → 443 [PSH, ACK] Seq=518 Ack=1148 Win=63093 Len=330 9 1.090563129 192.168.1.40 → 192.168.4.221 TCP 384 [TCP Retransmission] 45296 → 443 [PSH, ACK] Seq=518 Ack=1148 Win=63093 Len=330 10 2.370580702 192.168.1.40 → 192.168.4.221 TCP 384 [TCP Retransmission] 45296 → 443 [PSH, ACK] Seq=518 Ack=1148 Win=63093 Len=330 11 3.223508406 192.168.4.221 → 192.168.1.40 TLSv1.2 105 Change Cipher Spec, Encrypted Handshake Message 12 3.223704998 192.168.4.221 → 192.168.1.40 TCP 60 [TCP Dup ACK 11#1] 443 → 45296 [ACK] Seq=1199 Ack=848 Win=16673 Len=0 13 3.224003885 192.168.4.221 → 192.168.1.40 TCP 60 [TCP Dup ACK 11#2] 443 → 45296 [ACK] Seq=1199 Ack=848 Win=16673 Len=0 14 3.224215422 192.168.1.40 → 192.168.4.221 TLSv1.2 159 Application DataI noticed that curl was complaining about server not supporting ALPN, so I tried enabling that, but it didn't seem to have any effect on the TLS handshake speed...
Code:
#define MBEDTLS_SSL_ALPNStatistics: Posted by vadelma-pi — Sun Jan 07, 2024 3:58 am