Can set couch_peruser.database_prefix with illegal characters

[paulbert]

Description

When using couch_peruser it is allowed to set database_prefix with illegal characters for a database name. For us this resulted in CouchDB crashing and being unable to start until we changed the configuration manually in local.ini

Steps to Reproduce

1. Set up single node CouchDB
2. Run

curl -H 'Content-Type: application/json' -X PUT http:https://localhost:5984/_node/nonode@nohost/_config/couch_peruser/database_prefix -d '"userdb-.-"'
curl -H 'Content-Type: application/json' -X PUT http:https://localhost:5984/_node/nonode@nohost/_config/couch_peruser/enable -d '"true"'

3. CouchDB has now crashed, and will crash immediately on restart. The error messages I saw after attempted restart were:

Error: {error,{illegal_database_name,<<"userdb-.-">>}}
[error] 2019-10-31T14:28:37.769379Z nonode@nohost <0.416.0> -------- CRASH REPORT Process couch_peruser (<0.416.0>) with 0 neighbors exited with reason: bad return value {error,{illegal_database_name,<<"userdb-.-">>}} at gen_server:init_it/6(line:356) <= proc_lib:init_p_do_apply/3(line:247); initial_call: {couch_peruser,init,['Argument__1']}, ancestors: [couch_peruser_sup,<0.414.0>], messages: [], links: [<0.415.0>,<0.87.0>], dictionary: [], trap_exit: false, status: running, heap_size: 1598, stack_size: 27, reductions: 1586
[error] 2019-10-31T14:28:37.769649Z nonode@nohost <0.415.0> -------- Supervisor couch_peruser_sup had child couch_peruser started with couch_peruser:start_link() at undefined exit with reason bad return value {error,{illegal_database_name,<<"userdb-.-">>}} in context start_error
[error] 2019-10-31T14:28:37.770164Z nonode@nohost <0.413.0> -------- CRASH REPORT Process  (<0.413.0>) with 0 neighbors exited with reason: {{shutdown,{failed_to_start_child,couch_peruser,{bad_return_value,{error,{illegal_database_name,<<"userdb-.-">>}}}}},{couch_peruser_app,start,[normal,[]]}} at application_master:init/4(line:134) <= proc_lib:init_p_do_apply/3(line:247); initial_call: {application_master,init,['Argument__1','Argument__2',...]}, ancestors: [<0.412.0>], messages: [{'EXIT',<0.414.0>,normal}], links: [<0.412.0>,<0.9.0>], dictionary: [], trap_exit: true, status: running, heap_size: 376, stack_size: 27, reductions: 105
[info] 2019-10-31T14:28:37.770459Z nonode@nohost <0.9.0> -------- Application couch_peruser exited with reason: {{shutdown,{failed_to_start_child,couch_peruser,{bad_return_value,{error,{illegal_database_name,<<"userdb-.-">>}}}}},{couch_peruser_app,start,[normal,[]]}}

Expected Behaviour

Setting couch_peruser.database_prefix to a value with invalid database characters will throw an error.

Your Environment

• CouchDB Version used: 2.3.1
• Operating System and version: Debain 10 (buster)

[mnxumalo]

Hi,
Can I work on this bug?

[mnxumalo]

@wohali is there anyone working on this bug?

[wohali]

If you don't see a pull request open for it, then no.