Obfuscate credentials in shovel worker states to avoid plaintext pass…

[thuandb]

…words being logged on crashes

When a shovel is configured incorrectly (either with incorrect username/password, or the targeted broker is down or unreachable), rabbit_shovel_worker crashes with its full state including URIs with plain text passwords being logged in the crash log, and sometimes also in the default log.

• This is an example of a crash log having password logged in plaintext:

2021-08-04 02:22:23 =SUPERVISOR REPORT====
     Supervisor: {<0.740.0>,rabbit_shovel_dyn_worker_sup}
     Context:    child_terminated
     Reason:     shutdown
     Offender:   [{pid,<0.860.0>},{id,{<<"/">>,<<"notWorkingShovel">>}},{mfargs,{rabbit_shovel_worker,start_link,[dynamic,{<<"/">>,<<"notWorkingShovel">>},[{<<"ack-mode">>,<<"on-confirm">>},{<<"dest-add-forward-headers">>,false},{<<"dest-protocol">>,<<"amqp091">>},{<<"dest-uri">>,<<"amqp://">>},{<<"src-delete-after">>,<<"never">>},{<<"src-protocol">>,<<"amqp091">>},{<<"src-queue">>,<<"test-shovel-queue">>},{<<"src-uri">>,<<"amqp://user:pass@wronghost.com:5671">>}]]}},{restart_type,{permanent,5}},{shutdown,4294967295},{child_type,worker}]

• When node is restarted, plain text password get logged in default log too:

2021-08-04 02:22:07.857 [info] <0.740.0> supervisor: {<0.740.0>,rabbit_shovel_dyn_worker_sup}, errorContext: child_terminated, reason: shutdown, offender: [{pid,<0.741.0>},{id,{<<"/">>,<<"notWorkingShovel">>}},{mfargs,{rabbit_shovel_worker,start_link,[dynamic,{<<"/">>,<<"notWorkingShovel">>},[{<<"ack-mode">>,<<"on-confirm">>},{<<"dest-add-forward-headers">>,false},{<<"dest-protocol">>,<<"amqp091">>},{<<"dest-uri">>,<<"amqp://">>},{<<"src-delete-after">>,<<"never">>},{<<"src-protocol">>,<<"amqp091">>},{<<"src-queue">>,<<"test-shovel-queue">>},{<<"src-uri">>,<<"amqp://user:pass@wronghost.com:5671">>}]]}},{restart_type,{permanent,5}},{shutdown,4294967295},{child_type,worker}]

The issue was reported in the past: rabbitmq#2709

Proposed Changes

The following change is an implementation to avoid plain text passwords being logged with the shovel workers' states upon crashing. Specifically, the change is to only store obfuscated URIs in the shovel workers' states and deobfuscate them when accessed. As a result, when shovel workers crash, the passwords will not be logged in plain text. The error logs from the shovel plugin will tell users what went wrong.

For example, when the targeted broker's DNS is not correct, the error message in default log indicates what the problem is:

2021-07-31 17:25:29.294574+00:00 [erro] <0.22741.5> Shovel 'notWorkingShovel' failed to connect (URI: amqp://wronghost.com:5671): unknown host (failed to resolve hostname)
2021-07-31 17:25:29.294677+00:00 [erro] <0.22741.5> Shovel 'notWorkingShovel' has no more URIs to try for connection
2021-07-31 17:25:29.294727+00:00 [erro] <0.22741.5> Shovel 'notWorkingShovel' could not connect to source

The crash log will not show the password in plain text:

2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>     supervisor: {<0.22740.5>,rabbit_shovel_dyn_worker_sup}
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>     errorContext: child_terminated
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>     reason: shutdown
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>     offender: [{pid,<0.22741.5>},
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                {id,{<<"/">>,<<"notWorkingShovel">>}},
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                {mfargs,
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                    {rabbit_shovel_worker,start_link,
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                        [dynamic,
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                         {<<"/">>,<<"notWorkingShovel">>},
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                         [{<<"dest-uri">>,
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                           [{encrypted,
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                                <<"HtDNAVY31TtCO2I1UByk1OWwXn5AfSl/zouMBki3NG1nnAWxF3WpfEu7lmz//btl">>}]},
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                          {<<"src-uri">>,
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                           [{encrypted,
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                                <<"m1B4OoxBTldD2Xo5VuDepCsfcmALH/mM61IuATxMBvS+MPJqxfUVfCtLh+ZCikouPmdGX1CkoOgVh+UIlmFN05ByuYsM3GmvcxjMjAvIvRo=">>}]},
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                          {<<"ack-mode">>,<<"on-confirm">>},
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                          {<<"dest-add-forward-headers">>,false},
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                          {<<"dest-protocol">>,<<"amqp091">>},
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                          {<<"src-delete-after">>,<<"never">>},
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                          {<<"src-protocol">>,<<"amqp091">>},
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                          {<<"src-queue">>,<<"test-shovel-queue">>}]]}},
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                {restart_type,{permanent,5}},
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                {shutdown,4294967295},
2021-07-31 17:25:29.294843+00:00 [erro] <0.22740.5>                {child_type,worker}]

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