我正在尝试使用TLS将MQTT客户端连接到MQTT代理。我使用的库是Paho MQTT C库：https://github.com/eclipse/paho.mqtt.c
但是，代理与客户端之间的连接不会成功，因此，我需要更多的说明和帮助来解决此问题。
根据Paho MQTT C文档中的SSL选项： https://www.eclipse.org/paho/files/mqttdoc/MQTTAsync/html/struct_m_q_t_t_async___s_s_l_options.html
我需要用正确的文件句柄和配置填充此结构，然后将其传递给“连接选项”结构。
我的机器（本地主机）上运行了一个蚊子中介。 这是配置文件：
# =================================================================
# Default listener
# =================================================================
# IP address/hostname to bind the default listener to. If not
# given, the default listener will not be bound to a specific
# address and so will be accessible to all network interfaces.
# bind_address ip-address/host name
#bind_address
# Port to use for the default listener.
port 8883
# -----------------------------------------------------------------
# Certificate based SSL/TLS support
# -----------------------------------------------------------------
# The following options can be used to enable SSL/TLS support for
# this listener. Note that the recommended port for MQTT over TLS
# is 8883, but this must be set manually.
#
# See also the mosquitto-tls man page.
# At least one of cafile or capath must be defined. They both
# define methods of accessing the PEM encoded Certificate
# Authority certificates that have signed your server certificate
# and that you wish to trust.
# cafile defines the path to a file containing the CA certificates.
# capath defines a directory that will be searched for files
# containing the CA certificates. For capath to work correctly, the
# certificate files must have ".crt" as the file ending and you must run
# "openssl rehash <path to capath>" each time you add/remove a certificate.
#capath
cafile /etc/mosquitto/ca_certificates/mqttRSACA.crt
# Path to the PEM encoded server certificate.
certfile /etc/mosquitto/certs/mqttrsabroker.crt
# Path to the PEM encoded keyfile.
keyfile /etc/mosquitto/certs/mqttrsabroker.key
# If you have require_certificate set to true, you can create a certificate
# revocation list file to revoke access to particular client certificates. If
# you have done this, use crlfile to point to the PEM encoded revocation file.
#crlfile
# If you wish to control which encryption ciphers are used, use the ciphers
# option. The list of available ciphers can be obtained using the "openssl
# ciphers" command and should be provided in the same format as the output of
# that command.
# If unset defaults to DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2:@STRENGTH
#ciphers DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2:@STRENGTH
# To allow the use of ephemeral DH key exchange, which provides forward
# security, the listener must load DH parameters. This can be specified with
# the dhparamfile option. The dhparamfile can be generated with the command
# e.g. "openssl dhparam -out dhparam.pem 2048"
#dhparamfile
# By default a TLS enabled listener will operate in a similar fashion to a
# https enabled web server, in that the server has a certificate signed by a CA
# and the client will verify that it is a trusted certificate. The overall aim
# is encryption of the network traffic. By setting require_certificate to true,
# the client must provide a valid certificate in order for the network
# connection to proceed. This allows access to the broker to be controlled
# outside of the mechanisms provided by MQTT.
#require_certificate false
# This option defines the version of the TLS protocol to use for this listener.
# The default value allows all of v1.3, v1.2 and v1.1. The valid values are
# tlsv1.3 tlsv1.2 and tlsv1.1.
tls_version tlsv1.2
我点击了以下链接： http://www.steves-internet-guide.com/mosquitto-tls/
我有一个具有以下配置的mqtt客户端：
conn_opts.keepAliveInterval = 20;
conn_opts.cleansession = 1;
conn_opts.onSuccess = onConnect;
conn_opts.onFailure = onConnectFailure;
conn_opts.context = (void*)&mqtt_ctx;
conn_opts.ssl = &ssl_opts;
// Set SSL options
ssl_opts.struct_version = 1;
ssl_opts.keyStore = key_store_file;
ssl_opts.trustStore = trust_store_file;
ssl_opts.sslVersion = MQTT_SSL_VERSION_TLS_1_2;
环境变量读取key_store_file和trust_store_file，它们指向：
key_store_file: mqttrsaclient.key
trust_store_file: mqttrsaclient.crt
两个文件均为PEM格式。
我设置了MQTT_C_CLIENT_TRACE=ON，这是我观察到的：
Starting Up!
Broker IP: ssl://127.0.0.1:8883
=========================================================
Trace Output
Product name: Eclipse Paho Asynchronous MQTT C Client Library
Version: 1.3.0
Build level: Wed Jul 31 15:23:35 PDT 2019
OpenSSL version: OpenSSL 1.1.1 11 Sep 2018
OpenSSL flags: compiler: gcc -fPIC -pthread -m64 -Wa,--noexecstack -Wall -Wa,--noexecstack -g -O2 -fdebug-prefix-map=/build/openssl-cn9tZy/openssl-1.1.1=. -fstack-protector-strong -Wformat -Werror=format-security -DOPENSSL_USE_NODELETE -DL_ENDIAN -DOPENSSL_PIC -DOPENSSL_CPUID_OBJ -DOPENSSL_IA32_SSE2 -DOPENSSL_BN_ASM_MONT -DOPENSSL_BN_ASM_MONT5 -DOPENSSL_BN_ASM_GF2m -DSHA1_ASM -DSHA256_ASM -DSHA512_ASM -DKECCAK1600_ASM -DRC4_ASM -DMD5_ASM -DAES_ASM -DVPAES_ASM -DBSAES_ASM -DGHASH_ASM -DECP_NISTZ256_ASM -DX2
OpenSSL build timestamp: built on: Thu Jun 20 17:36:28 2019 UTC
OpenSSL platform: platform: debian-amd64
OpenSSL directory: OPENSSLDIR: "/usr/lib/ssl"
/proc/version: Linux version 4.15.0-55-generic (buildd@lcy01-amd64-029) (gcc version 7.4.0 (Ubuntu 7.4.0-1ubuntu1~18.04.1)) #60-Ubuntu SMP Tue Jul 2 18:22:20 UTC 2019
=========================================================
19691231 160000.000 (299804416) (1)> Socket_outInitialize:131
19691231 160000.000 (299804416) (2)> SocketBuffer_initialize:94
19691231 160000.000 (299804416) (2)< SocketBuffer_initialize:98
19691231 160000.000 (299804416) (1)< Socket_outInitialize:144
19691231 160000.000 (299804416) (1)> SSLSocket_initialize:443
19691231 160000.000 (299804416) (2)> SSL_create_mutex:343
19691231 160000.000 (299804416) (2)< SSL_create_mutex:349 (0)
19691231 160000.000 (299804416) (2)> SSL_create_mutex:343
19691231 160000.000 (299804416) (2)< SSL_create_mutex:349 (0)
19691231 160000.000 (299804416) (1)< SSLSocket_initialize:487 (1)
19691231 160000.000 (299804416) (1)> MQTTStrncpy:848
19691231 160000.000 (299804416) (1)< MQTTStrncpy:858
19691231 160000.000 (299804416) (1)> MQTTStrncpy:848
19691231 160000.000 (299804416) (1)< MQTTStrncpy:858
19691231 160000.000 (299804416) (1)> MQTTPersistence_create:52
19691231 160000.000 (299804416) (1)< MQTTPersistence_create:98 (0)
19691231 160000.000 (299804416) (1)> MQTTPersistence_initialize:113
19691231 160000.000 (299804416) (1)< MQTTPersistence_initialize:121 (0)
19691231 160000.000 (299804416) (1)> MQTTAsync_restoreCommands:936
20190827 183834.980 0 commands restored for client am65x-ti-0
20190827 183834.980 (299804416) (1)< MQTTAsync_restoreCommands:974 (0)
20190827 183834.980 (299804416) (1)> MQTTPersistence_restoreMessageQueue:714
20190827 183834.980 0 queued messages restored for client am65x-ti-0
20190827 183834.980 (299804416) (1)< MQTTPersistence_restoreMessageQueue:753 (0)
20190827 183834.980 (299804416) (0)< MQTTAsync_createWithOptions:593 (0)
20190827 183834.980 (299804416) (0)> MQTTAsync_setCallbacks:2426
20190827 183834.980 (299804416) (0)< MQTTAsync_setCallbacks:2440 (-1)
20190827 183834.980 (299804416) (0)> MQTTAsync_connect:2738
20190827 183834.980 (299804416) (1)> Thread_start:69
20190827 183834.980 (299804416) (1)< Thread_start:79
20190827 183834.980 (299804416) (1)> Thread_start:69
20190827 183834.980 (291411712) (0)> MQTTAsync_sendThread:1784
20190827 183834.980 (299804416) (1)< Thread_start:79
20190827 183834.980 (283019008) (0)> MQTTAsync_receiveThread:2064
20190827 183834.980 (283019008) (1)> MQTTAsync_cycle:3663
20190827 183834.980 (283019008) (2)> Socket_getReadySocket:237
20190827 183834.980 (283019008) (2)< Socket_getReadySocket:309 (0)
20190827 183834.980 (283019008) (2)> MQTTAsync_sleep:420
20190827 183834.980 (299804416) (1)> MQTTStrncpy:848
20190827 183834.981 (299804416) (1)< MQTTStrncpy:858
20190827 183834.981 (291411712) (1)> Thread_wait_cond:411
20190827 183834.981 (299804416) (1)> MQTTStrncpy:848
20190827 183834.981 (299804416) (1)< MQTTStrncpy:858
20190827 183834.981 (299804416) (1)> MQTTAsync_addCommand:984
20190827 183834.981 (299804416) (2)> Thread_signal_cond:393
20190827 183834.981 (299804416) (2)< Thread_signal_cond:398 (0)
20190827 183834.981 (299804416) (1)< MQTTAsync_addCommand:1018 (0)
20190827 183834.981 (299804416) (0)< MQTTAsync_connect:3039 (0)
Connection Attempt Return Code: 0
20190827 183834.981 (291411712) (1)< Thread_wait_cond:419 (0)
20190827 183834.981 (291411712) (1)> MQTTAsync_checkTimeouts:1730
20190827 183834.981 (291411712) (1)< MQTTAsync_checkTimeouts:1778
20190827 183834.981 (291411712) (1)> MQTTAsync_processCommand:1324
20190827 183834.981 Connecting to serverURI 127.0.0.1:8883 with MQTT version 4
20190827 183834.981 (291411712) (2)> MQTTProtocol_connect:114
20190827 183834.981 (291411712) (3)> MQTTProtocol_addressPort:58
20190827 183834.981 (291411712) (3)< MQTTProtocol_addressPort:90
20190827 183834.981 (291411712) (3)> Socket_new:668
20190827 183834.981 New socket 3 for 127.0.0.1:8883, port 8883
20190827 183834.981 (291411712) (4)> Socket_addSocket:173
20190827 183834.981 (291411712) (5)> Socket_setnonblocking:85
20190827 183834.981 (291411712) (5)< Socket_setnonblocking:90 (0)
20190827 183834.981 (291411712) (4)< Socket_addSocket:196 (0)
20190827 183834.981 Connect pending
20190827 183834.981 (291411712) (3)< Socket_new:785 (115)
20190827 183834.981 (291411712) (2)< MQTTProtocol_connect:156 (115)
20190827 183834.981 (291411712) (2)> MQTTProperties_free:366
20190827 183834.981 (291411712) (2)< MQTTProperties_free:389
20190827 183834.981 (291411712) (1)< MQTTAsync_processCommand:1660 (1)
20190827 183834.981 (291411712) (1)> Thread_wait_cond:411
20190827 183834.981 (283019008) (2)< MQTTAsync_sleep:426
20190827 183834.981 (283019008) (2)> MQTTAsync_retry:3495
20190827 183834.981 (283019008) (3)> MQTTProtocol_keepalive:608
20190827 183834.981 (283019008) (3)< MQTTProtocol_keepalive:641
20190827 183834.981 (283019008) (3)> MQTTProtocol_retry:727
20190827 183834.981 (283019008) (3)< MQTTProtocol_retry:746
20190827 183834.981 (283019008) (2)< MQTTAsync_retry:3505
20190827 183834.981 (283019008) (1)< MQTTAsync_cycle:3810 (-1)
20190827 183834.981 (283019008) (1)> MQTTAsync_cycle:3663
20190827 183834.981 (283019008) (2)> Socket_getReadySocket:237
20190827 183835.081 (283019008) (3)> Socket_continueWrites:928
20190827 183835.081 (283019008) (3)< Socket_continueWrites:952 (0)
20190827 183835.081 (283019008) (3)> isReady:213
20190827 183835.081 (283019008) (3)< isReady:218 (1)
20190827 183835.081 (283019008) (2)< Socket_getReadySocket:309 (3)
20190827 183835.081 m->c->connect_state = 1
20190827 183835.081 (283019008) (2)> MQTTAsync_connecting:3513
20190827 183835.081 (283019008) (3)> MQTTProtocol_addressPort:58
20190827 183835.081 (283019008) (3)< MQTTProtocol_addressPort:90
20190827 183835.081 (283019008) (3)> SSLSocket_setSocketForSSL:647
20190827 183835.081 (283019008) (4)> SSLSocket_createContext:521
20190827 183835.081 (283019008) (5)> SSLSocket_error:97
20190827 183835.081 SSLSocket error (151584876) in SSL_CTX_use_certificate_chain_file for socket 3 rc 0 errno 2 No such file or directory
20190827 183835.081 (283019008) (5)< SSLSocket_error:117 (151584876)
20190827 183835.081 (283019008) (4)< SSLSocket_createContext:637 (0)
20190827 183835.081 (283019008) (3)< SSLSocket_setSocketForSSL:686 (0)
20190827 183835.081 (283019008) (3)> nextOrClose:1667
20190827 183835.081 (283019008) (4)> MQTTAsync_checkConn:467
20190827 183835.081 (283019008) (4)< MQTTAsync_checkConn:470 (1)
20190827 183835.081 (283019008) (4)> MQTTAsync_closeOnly:2559
20190827 183835.082 (283019008) (5)> MQTTProtocol_checkPendingWrites:1138
20190827 183835.082 (283019008) (5)< MQTTProtocol_checkPendingWrites:1155
20190827 183835.082 (283019008) (5)> WebSocket_close:397
20190827 183835.082 (283019008) (5)< WebSocket_close:450
20190827 183835.082 (283019008) (5)> SSLSocket_close:852
20190827 183835.082 (283019008) (6)> SSLSocket_destroyContext:839
20190827 183835.082 (283019008) (6)< SSLSocket_destroyContext:843
20190827 183835.082 (283019008) (5)< SSLSocket_close:864 (1)
20190827 183835.082 (283019008) (5)> Socket_close:613
20190827 183835.082 (283019008) (6)> Socket_close_only:587
20190827 183835.082 (283019008) (6)< Socket_close_only:601 (0)
20190827 183835.082 (283019008) (6)> Socket_abortWrite:895
20190827 183835.082 (283019008) (6)< Socket_abortWrite:913 (0)
20190827 183835.082 (283019008) (6)> SocketBuffer_cleanup:136
20190827 183835.082 (283019008) (6)< SocketBuffer_cleanup:148
20190827 183835.082 Removed socket 3
20190827 183835.082 (283019008) (5)< Socket_close:640
20190827 183835.082 (283019008) (4)< MQTTAsync_closeOnly:2581
20190827 183835.082 Connect failed, more to try
20190827 183835.082 (283019008) (4)> MQTTAsync_addCommand:984
20190827 183835.082 (283019008) (5)> Thread_signal_cond:393
20190827 183835.082 (283019008) (5)< Thread_signal_cond:398 (0)
20190827 183835.082 (283019008) (4)< MQTTAsync_addCommand:1018 (0)
20190827 183835.082 (283019008) (3)< nextOrClose:1720
20190827 183835.082 (283019008) (2)< MQTTAsync_connecting:3652 (-1)
20190827 183835.082 m->c->connect_state = 0
20190827 183835.082 CONNECT sent, *rc is -1
20190827 183835.082 (291411712) (1)< Thread_wait_cond:419 (0)
20190827 183835.082 (291411712) (1)> MQTTAsync_checkTimeouts:1730
20190827 183835.082 (291411712) (1)< MQTTAsync_checkTimeouts:1778
20190827 183835.082 (291411712) (1)> MQTTAsync_processCommand:1324
20190827 183835.082 (283019008) (2)> MQTTAsync_retry:3495
20190827 183835.082 (283019008) (3)> MQTTProtocol_retry:727
20190827 183835.082 (283019008) (3)< MQTTProtocol_retry:746
20190827 183835.082 (283019008) (2)< MQTTAsync_retry:3505
20190827 183835.082 (283019008) (1)< MQTTAsync_cycle:3810 (-1)
20190827 183835.082 Connecting to serverURI 127.0.0.1:8883 with MQTT version 3
20190827 183835.082 (291411712) (2)> MQTTProtocol_connect:114
20190827 183835.082 (291411712) (3)> MQTTProtocol_addressPort:58
20190827 183835.082 (291411712) (3)< MQTTProtocol_addressPort:90
20190827 183835.083 (291411712) (3)> Socket_new:668
20190827 183835.083 New socket 3 for 127.0.0.1:8883, port 8883
20190827 183835.083 (291411712) (4)> Socket_addSocket:173
20190827 183835.083 (291411712) (5)> Socket_setnonblocking:85
20190827 183835.083 (291411712) (5)< Socket_setnonblocking:90 (0)
20190827 183835.083 (291411712) (4)< Socket_addSocket:196 (0)
20190827 183835.083 Connect pending
20190827 183835.083 (291411712) (3)< Socket_new:785 (115)
20190827 183835.083 (291411712) (2)< MQTTProtocol_connect:156 (115)
20190827 183835.083 (291411712) (2)> MQTTProperties_free:366
20190827 183835.083 (291411712) (2)< MQTTProperties_free:389
20190827 183835.083 (291411712) (1)< MQTTAsync_processCommand:1660 (1)
20190827 183835.083 (291411712) (1)> Thread_wait_cond:411
20190827 183835.083 Error from MQTTAsync_cycle() - removing socket 3
20190827 183835.083 (283019008) (1)> nextOrClose:1667
20190827 183835.083 (283019008) (2)> MQTTAsync_checkConn:467
20190827 183835.083 (283019008) (2)< MQTTAsync_checkConn:470 (0)
20190827 183835.083 (283019008) (2)> MQTTAsync_closeSession:2587
20190827 183835.083 (283019008) (3)> MQTTAsync_closeOnly:2559
20190827 183835.083 (283019008) (4)> MQTTProtocol_checkPendingWrites:1138
20190827 183835.083 (283019008) (4)< MQTTProtocol_checkPendingWrites:1155
20190827 183835.083 (283019008) (4)> WebSocket_close:397
20190827 183835.083 (283019008) (4)< WebSocket_close:450
20190827 183835.083 (283019008) (4)> SSLSocket_close:852
20190827 183835.083 (283019008) (5)> SSLSocket_destroyContext:839
20190827 183835.083 (283019008) (5)< SSLSocket_destroyContext:843
20190827 183835.083 (283019008) (4)< SSLSocket_close:864 (1)
20190827 183835.083 (283019008) (4)> Socket_close:613
20190827 183835.083 (283019008) (5)> Socket_close_only:587
20190827 183835.083 (283019008) (5)< Socket_close_only:601 (0)
20190827 183835.083 (283019008) (5)> Socket_abortWrite:895
20190827 183835.083 (283019008) (5)< Socket_abortWrite:913 (0)
20190827 183835.083 (283019008) (5)> SocketBuffer_cleanup:136
20190827 183835.083 (283019008) (5)< SocketBuffer_cleanup:148
20190827 183835.083 Removed socket 3
20190827 183835.083 (283019008) (4)< Socket_close:640
20190827 183835.083 (283019008) (3)< MQTTAsync_closeOnly:2581
20190827 183835.083 (283019008) (3)> MQTTAsync_cleanSession:2616
20190827 183835.083 (283019008) (4)> MQTTPersistence_clear:160
20190827 183835.083 (283019008) (4)< MQTTPersistence_clear:164 (0)
20190827 183835.084 (283019008) (4)> MQTTProtocol_emptyMessageList:809
20190827 183835.084 (283019008) (4)< MQTTProtocol_emptyMessageList:818
20190827 183835.084 (283019008) (4)> MQTTProtocol_emptyMessageList:809
20190827 183835.084 (283019008) (4)< MQTTProtocol_emptyMessageList:818
20190827 183835.084 (283019008) (4)> MQTTAsync_emptyMessageQueue:1820
20190827 183835.084 (283019008) (4)< MQTTAsync_emptyMessageQueue:1834
20190827 183835.084 (283019008) (4)> MQTTAsync_removeResponsesAndCommands:1844
20190827 183835.084 0 responses removed for client am65x-ti-0
20190827 183835.084 0 commands removed for client am65x-ti-0
20190827 183835.084 (283019008) (4)< MQTTAsync_removeResponsesAndCommands:1929
20190827 183835.084 (283019008) (3)< MQTTAsync_cleanSession:2632 (0)
20190827 183835.084 (283019008) (2)< MQTTAsync_closeSession:2594
20190827 183835.084 Calling connect failure for client am65x-ti-0
Connect failed, rc -1
20190827 183835.084 (283019008) (1)< nextOrClose:1720
20190827 183835.084 (283019008) (1)> MQTTAsync_cycle:3663
20190827 183835.084 (283019008) (2)> Socket_getReadySocket:237
20190827 183835.084 (283019008) (2)< Socket_getReadySocket:309 (0)
20190827 183835.084 (283019008) (2)> MQTTAsync_sleep:420
20190827 183835.084 (283019008) (2)< MQTTAsync_sleep:426
20190827 183835.084 (283019008) (2)> MQTTAsync_retry:3495
20190827 183835.184 (283019008) (3)> MQTTProtocol_retry:727
20190827 183835.184 (283019008) (3)< MQTTProtocol_retry:746
20190827 183835.184 (283019008) (2)< MQTTAsync_retry:3505
20190827 183835.184 (283019008) (1)< MQTTAsync_cycle:3810 (-1)
20190827 183835.184 (283019008) (1)> MQTTAsync_cycle:3663
20190827 183835.184 (283019008) (2)> Socket_getReadySocket:237
20190827 183835.184 (283019008) (2)< Socket_getReadySocket:309 (0)
20190827 183835.184 (283019008) (2)> MQTTAsync_sleep:420
20190827 183835.184 (283019008) (2)< MQTTAsync_sleep:426
20190827 183835.184 (283019008) (2)> MQTTAsync_retry:3495
20190827 183835.184 (283019008) (3)> MQTTProtocol_retry:727
20190827 183835.184 (283019008) (3)< MQTTProtocol_retry:746
20190827 183835.184 (283019008) (2)< MQTTAsync_retry:3505
20190827 183835.184 (283019008) (1)< MQTTAsync_cycle:3810 (-1)
20190827 183835.184 (283019008) (1)> MQTTAsync_cycle:3663
20190827 183835.184 (283019008) (2)> Socket_getReadySocket:237
20190827 183835.184 (283019008) (2)< Socket_getReadySocket:309 (0)
20190827 183835.184 (283019008) (2)> MQTTAsync_sleep:420
20190827 183835.184 (283019008) (2)< MQTTAsync_sleep:426
20190827 183835.184 (283019008) (2)> MQTTAsync_retry:3495
20190827 183835.385 (283019008) (3)> MQTTProtocol_retry:727
20190827 183835.385 (283019008) (3)< MQTTProtocol_retry:746
20190827 183835.385 (283019008) (2)< MQTTAsync_retry:3505
20190827 183835.385 (283019008) (1)< MQTTAsync_cycle:3810 (-1)
20190827 183835.385 (283019008) (1)> MQTTAsync_cycle:3663
20190827 183835.385 (283019008) (2)> Socket_getReadySocket:237
20190827 183835.385 (283019008) (2)< Socket_getReadySocket:309 (0)
20190827 183835.385 (283019008) (2)> MQTTAsync_sleep:420
20190827 183835.385 (283019008) (2)< MQTTAsync_sleep:426
20190827 183835.385 (283019008) (2)> MQTTAsync_retry:3495
20190827 183835.385 (283019008) (3)> MQTTProtocol_retry:727
20190827 183835.385 (283019008) (3)< MQTTProtocol_retry:746
20190827 183835.385 (283019008) (2)< MQTTAsync_retry:3505
20190827 183835.385 (283019008) (1)< MQTTAsync_cycle:3810 (-1)
20190827 183835.385 (283019008) (1)> MQTTAsync_cycle:3663
20190827 183835.385 (283019008) (2)> Socket_getReadySocket:237
20190827 183835.385 (283019008) (2)< Socket_getReadySocket:309 (0)
20190827 183835.385 (283019008) (2)> MQTTAsync_sleep:420
20190827 183835.385 (283019008) (2)< MQTTAsync_sleep:426
20190827 183835.385 (283019008) (2)> MQTTAsync_retry:3495
20190827 183835.585 (283019008) (3)> MQTTProtocol_retry:727
20190827 183835.585 (283019008) (3)< MQTTProtocol_retry:746
20190827 183835.585 (283019008) (2)< MQTTAsync_retry:3505
20190827 183835.585 (283019008) (1)< MQTTAsync_cycle:3810 (-1)
20190827 183835.585 (283019008) (1)> MQTTAsync_cycle:3663
20190827 183835.585 (283019008) (2)> Socket_getReadySocket:237
20190827 183835.585 (283019008) (2)< Socket_getReadySocket:309 (0)
20190827 183835.585 (283019008) (2)> MQTTAsync_sleep:420
20190827 183835.585 (283019008) (2)< MQTTAsync_sleep:426
20190827 183835.585 (283019008) (2)> MQTTAsync_retry:3495
20190827 183835.585 (283019008) (3)> MQTTProtocol_retry:727
20190827 183835.585 (283019008) (3)< MQTTProtocol_retry:746
20190827 183835.585 (283019008) (2)< MQTTAsync_retry:3505
20190827 183835.585 (283019008) (1)< MQTTAsync_cycle:3810 (-1)
20190827 183835.585 (283019008) (1)> MQTTAsync_cycle:3663
20190827 183835.585 (283019008) (2)> Socket_getReadySocket:237
20190827 183835.585 (283019008) (2)< Socket_getReadySocket:309 (0)
20190827 183835.585 (283019008) (2)> MQTTAsync_sleep:420
20190827 183835.585 (283019008) (2)< MQTTAsync_sleep:426
20190827 183835.585 (283019008) (2)> MQTTAsync_retry:3495
20190827 183835.786 (283019008) (3)> MQTTProtocol_retry:727
20190827 183835.786 (283019008) (3)< MQTTProtocol_retry:746
20190827 183835.786 (283019008) (2)< MQTTAsync_retry:3505
20190827 183835.786 (283019008) (1)< MQTTAsync_cycle:3810 (-1)
20190827 183835.786 (283019008) (1)> MQTTAsync_cycle:3663
20190827 183835.786 (283019008) (2)> Socket_getReadySocket:237
20190827 183835.786 (283019008) (2)< Socket_getReadySocket:309 (0)
20190827 183835.786 (283019008) (2)> MQTTAsync_sleep:420
20190827 183835.786 (283019008) (2)< MQTTAsync_sleep:426
20190827 183835.786 (283019008) (2)> MQTTAsync_retry:3495
20190827 183835.786 (283019008) (3)> MQTTProtocol_retry:727
20190827 183835.786 (283019008) (3)< MQTTProtocol_retry:746
20190827 183835.786 (283019008) (2)< MQTTAsync_retry:3505
20190827 183835.786 (283019008) (1)< MQTTAsync_cycle:3810 (-1)
20190827 183835.786 (283019008) (1)> MQTTAsync_cycle:3663
20190827 183835.786 (283019008) (2)> Socket_getReadySocket:237
20190827 183835.786 (283019008) (2)< Socket_getReadySocket:309 (0)
20190827 183835.786 (283019008) (2)> MQTTAsync_sleep:420
专门看这一行：
20190827 183835.081 SSLSocket error (151584876) in SSL_CTX_use_certificate_chain_file for socket 3 rc 0 errno 2 No such file or directory
在经纪人方面：
1566956315: New connection from 127.0.0.1 on port 8883.
1566956315: Socket error on client <unknown>, disconnecting.
我不确定自己想念什么。
深入了解正确设置SSL选项将很有帮助。
-----------------编辑---------------
正如Marco在评论中建议的那样，我跑了strace -e trace=open,openat,stat,fstat -s200 ./mqttTest
`
我用您建议的命令尝试了它，这是输出（我关闭了MQTT的跟踪）。
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=148012, ...}) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libpthread.so.0", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0755, st_size=144976, ...}) = 0
openat(AT_FDCWD, "/usr/local/lib/libpaho-mqtt3as.so.1", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=609680, ...}) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0755, st_size=2030544, ...}) = 0
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/libssl.so.1.1", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=577312, ...}) = 0
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/libcrypto.so.1.1", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=2917216, ...}) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libdl.so.2", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=14560, ...}) = 0
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 1), ...}) = 0
Starting Up!
Broker IP: ssl://127.0.0.1:8883
Connection Attempt Return Code: 0
Connect failed, rc -1