Additional TLS troubleshooting information (#3346)

Add additional TLS troubleshooting information to the TLS doc.
Also remove outdated information from Fabric v1.1.

Signed-off-by: David Enyeart <enyeart@us.ibm.com>
(cherry picked from commit 0b2e6b5)

docs/source/enable_tls.rst

@@ -125,21 +125,27 @@ as well:
 Debugging TLS issues
 --------------------
 
-Before debugging TLS issues, it is advisable to enable ``GRPC debug`` on both the TLS client
-and the server side to get additional information. To enable ``GRPC debug``, set the
-environment variable ``FABRIC_LOGGING_SPEC`` to include ``grpc=debug``. For example, to
-set the default logging level to ``INFO`` and the GRPC logging level to ``DEBUG``, set
-the logging specification to ``grpc=debug:info``.
+If you see the error message ``remote error: tls: bad certificate`` on the server side
+(for example on the peer node or ordering service node when making requests from a client),
+it usually means that the client is not configured to trust the signer of the server's TLS certificate.
+Check the client's ``CORE_PEER_TLS_ROOTCERT_FILE`` (for connections to peer nodes)
+or ``--cafile`` (for connections to orderer nodes).
+The corresponding error on the client side in these cases is the handshake error ``x509: certificate signed by unknown authority``
+and ultimately connection failure with ``context deadline exceeded``.
 
 If you see the error message ``remote error: tls: bad certificate`` on the client side, it
 usually means that the TLS server has enabled client authentication and the server either did
 not receive the correct client certificate or it received a client certificate that it does
 not trust. Make sure the client is sending its certificate and that it has been signed by one
 of the CA certificates trusted by the peer or orderer node.
 
-If you see the error message ``remote error: tls: bad certificate`` in your chaincode logs,
-ensure that your chaincode has been built using the chaincode shim provided with Fabric v1.1
-or newer.
+To receive additional debug information, enable ``GRPC debug`` on both the TLS client
+and the server side to get additional information. To enable ``GRPC debug``, set the
+environment variable ``FABRIC_LOGGING_SPEC`` to include ``grpc=debug``. For example, to
+set the default logging level to ``INFO`` and the GRPC logging level to ``DEBUG``, set
+the logging specification to ``grpc=debug:info``.
+
+You can check a TLS certificate against a trusted CA certificate by using the "openssl verify" command.
 
 .. Licensed under Creative Commons Attribution 4.0 International License
    https://creativecommons.org/licenses/by/4.0/