[ssl] OpenSSL Command to check if a server is presenting a certificate

I encountered the write:errno=104 attempting to test connecting to an SSL-enabled RabbitMQ broker port with openssl s_client.

The issue turned out to be simply that the user RabbitMQ was running as did not have read permissions on the certificate file. There was little-to-no useful logging in RabbitMQ.

Examples related to ssl

Requests (Caused by SSLError("Can't connect to HTTPS URL because the SSL module is not available.") Error in PyCharm requesting website A fatal error occurred while creating a TLS client credential. The internal error state is 10013 curl: (35) error:1408F10B:SSL routines:ssl3_get_record:wrong version number How to install OpenSSL in windows 10? ssl.SSLError: tlsv1 alert protocol version Invalid self signed SSL cert - "Subject Alternative Name Missing" "SSL certificate verify failed" using pip to install packages ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:749) Powershell Invoke-WebRequest Fails with SSL/TLS Secure Channel "ssl module in Python is not available" when installing package with pip3

Examples related to openssl

dyld: Library not loaded: /usr/local/opt/openssl/lib/libssl.1.0.0.dylib How to install OpenSSL in windows 10? SSL_connect: SSL_ERROR_SYSCALL in connection to github.com:443 How to fix: fatal error: openssl/opensslv.h: No such file or directory in RedHat 7 Homebrew refusing to link OpenSSL Solving sslv3 alert handshake failure when trying to use a client certificate How to install latest version of openssl Mac OS X El Capitan How to resolve the "EVP_DecryptFInal_ex: bad decrypt" during file decryption SSL error SSL3_GET_SERVER_CERTIFICATE:certificate verify failed Can't get private key with openssl (no start line:pem_lib.c:703:Expecting: ANY PRIVATE KEY)