ID2中的mbedtls_ssl_handshake返回错误

在使用ID2 因特网设备的身份识别认证时，总是返回错误，如0x7780或者0x7280等，是怎么回事呢？

[10:16:34.554]收←◆I (2044) wifi: n:11 0, o:1 0, ap:255 255, sta:11 0, prof:1

[10:16:35.396]收←◆I (2888) wifi: state: init -> auth (b0)

[10:16:35.430]收←◆I (2922) wifi: state: auth -> assoc (0)

[10:16:35.465]收←◆I (2957) wifi: state: assoc -> run (10)

[10:16:35.801]收←◆I (3292) wifi: connected with S2G, channel 11
I (3293) wifi: pm start, type: 1

D (3293) event: SYSTEM_EVENT_STA_CONNECTED, ssid:S2G, ssid_len:7, bssid:28:6c:07:4f:c6:e5, channel:11, authmode:3[0m
D (3300) tcpip_adapter: check: local, if=0 fn=0x400d6070
[0m
D (3305) tcpip_adapter: check: local, if=0 fn=
[10:16:35.854]收←◆0x400d6a84
[0m
D (3311) tcpip_adapter: dhcp client init ip/mask/gw to all-0[0m
D (3316) tcpip_adapter: if0 start ip lost tmr: enter[0m
D (3322) tcpip_adapter: if0 start ip lost tmr: no need start because netif=0x3ffdd420 interval=120 ip=0[0m
D (3333) tcpip_adapter: dhcp cl