As per 2019-03-11 I am archiving this repository and closing all currently open issues and pull requests without prejudice. The repository will continue to exist and you are welcome to work on your own fork of it, as long as you observe the LICENSEs.
I have not used the mosquitto-auth-plug myself for years now, but my users expect, nay, demand, that I support and help them with it. We've received over 580 stars (thank you for that!), and yet some people can't even be bothered to read the documentation and then send me private e-mails or DMs on Twitter, etc. to complain and/or ask for help. I'm tired of having to work on understanding and fixing issues users are experiencing with the software. I'm also a bit tired of the lack of help I've received for this project.
The original README begins below this line.
This is a plugin to authenticate and authorize Mosquitto users from one or more of a variety of back-ends:
- CDB
- Files
- HTTP (custom HTTP API)
- JWT
- LDAP
- MongoDB
- MySQL
- PostgreSQL
- Redis key/value store
- SQLite3 database
- TLS PSK (the
pskback-end is a bit of a shim which piggy-backs on the other database back-ends)
This plugin can perform authentication (check username / password) and authorization (grant permission to subscribe and/or publish to specific topics via ACL). Currently, not all back-ends have the same capabilities (see the section on the back-end you're interested in).
| Capability | cdb | files | http | jwt | ldap | mongo | mysql | postgres | psk | redis | sqlite |
|---|---|---|---|---|---|---|---|---|---|---|---|
| authentication | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y |
| superusers | Y | Y | Y | Y | Y | 3 | |||||
| acl checking | 2 | Y | Y | Y | Y | Y | Y | 3 | 1 | 2 | |
| static superusers | Y | Y | Y | Y | Y | Y | Y | 3 | Y | Y |
- Topic wildcards (+/#) are not supported
- Currently not implemented; back-end returns TRUE
- Dependent on the database used by PSK
Multiple back-ends can be configured simultaneously for authentication, and they're attempted in
the order you specify. Once a user has been authenticated, the same back-end is used to
check authorization (ACLs). Superusers are checked for in all back-ends.
The configuration option is called auth_opt_backends and it takes a
comma-separated list of back-end names which are checked in exactly that order.
auth_opt_backends cdb,sqlite,mysql,redis,postgres,http,jwt,mongo
Note: anonymous MQTT connections are assigned a username configured in the
plugin as auth_opt_anonusername and they
are handled by a so-called fallback back-end which is the first configured
back-end.
Passwords are obtained from the back-end as PBKDF2 strings (see Passwords below). If you store a clear-text password or any hash not generated the same way, the comparison and the authentication will fail.
The mysql and mongo back-ends support expansion of %c and %u as clientid and username
respectively. This allows ACLs in the database to look like this:
+-----------+---------------------------------+----+
| username | topic | rw |
+-----------+---------------------------------+----+
| bridge-01 | $SYS/broker/connection/%c/state | 2 |
+-----------+---------------------------------+----+
The plugin supports so-called superusers. These are usernames exempt from ACL checking. In other words, if a user is a superuser, that user can access any topic without needing ACLs.
A static superuser is one configured with the fnmatch(3) auth_opt_superusers
option. Regular superusers are configured (i.e., enabled) from within the
particular database back-end. Effectively, both are identical in that ACL
checking is disabled if a user is a superuser.
Note that not all back-ends currently have 'superuser' queries implemented.
This is a todo and the auth_opt_superusers option will probably disappear when it is finished.
In order to compile the plugin you'll require:
- a copy of the Mosquitto source code together with the libraries required for the back-end you want to use in the plugin, and
- a recent version of OpenSSL (if the version with your OS, e.g., OS X, is too old, you may need to use one supplied by home brew or build your own).
Copy config.mk.in to config.mk and modify config.mk to suit your building environment. In particular, you have
to configure which back-ends you want to provide as well as the path to the
Mosquitto source and its library, and possibly the path to OpenSSL (OPENSSLDIR).
After a make you should have a shared object called auth-plug.so
which you will reference in your mosquitto.conf.
The plugin is configured in Mosquitto's configuration file (typically mosquitto.conf),
and it is loaded into Mosquitto auth with the auth_plugin option.
auth_plugin /path/to/auth-plug.so
Options therein with a leading auth_opt_ are handed to the plugin. The following
"global" auth_opt_* plugin options exist:
| Option | default | Mandatory | Meaning |
|---|---|---|---|
| backends | Y | comma-separated list of back-ends to load | |
| superusers | fnmatch(3) case-sensitive string | ||
| log_quiet | false | don't log DEBUG messages | |
| cacheseconds | Deprecated. Alias for acl_cacheseconds | ||
| acl_cacheseconds | 300 | number of seconds to cache ACL lookups. 0 disables | |
| auth_cacheseconds | 0 | number of seconds to cache AUTH lookups. 0 disables | |
| acl_cachejitter | 0 | maximum number of seconds to add/remove to ACL lookups cache TTL. 0 disables | |
| auth_cachejitter | 0 | maximum number of seconds to add/remove to AUTH lookups cache TTL. 0 disables |
Individual back-ends each have various additional options described in the sections below.
There are two caches, one for ACL and another for authentication. By default only the ACL cache is enabled.
After a backend responds (postitively or negatively) to an ACL or AUTH lookup, the result will be kept in cache for
the configured TTL. The same ACL lookup will be served from the cache as long as the TTL is valid.
The configured TTL is the auth_cacheseconds/acl_cacheseconds combined with a random value between -auth_/acl_cachejitter and +auth_/acl_cachejitter.
For example, with an acl_cacheseconds of 300 and acl_cachejitter of 10, ACL lookup TTLs are distributed between 290 and 310 seconds.
Set auth/acl_cachejitter to 0 disable any randomization of cache TTL. Setting auth/acl_cacheseconds to 0 disables caching entirely. Caching is useful when your backend lookup is expensive. Remember that ACL lookup will be performed for each message which is sent/received on a topic. Jitter is useful to reduce lookup storms that could occur every auth/acl_cacheseconds if lots of clients connect at the same time (for example, after a server restart, all your clients may reconnect immediately and each cause ACL lookups every acl_cacheseconds).
The mysql back-end is currently the most feature-complete: it supports
obtaining passwords, checking for superusers, and verifying ACLs by
configuring up to three distinct SQL queries used to obtain those results.
You configure the SQL queries in order to adapt to whichever schema you currently have.
The following auth_opt_ options are supported by the mysql back-end:
| Option | default | Mandatory | Meaning |
|---|---|---|---|
| host | localhost | hostname/address | |
| port | 3306 | TCP port | |
| user | username | ||
| pass | password | ||
| dbname | Y | database name | |
| userquery | Y | SQL for users | |
| superquery | SQL for superusers | ||
| aclquery | SQL for ACLs | ||
| mysql_opt_reconnect | true | enable MYSQL_OPT_RECONNECT option | |
| mysql_auto_connect | true | enable auto_connect function | |
| anonusername | anonymous | username to use for anonymous connections | |
| ssl_enabled | false | enable SSL | |
| ssl_key | path name of client private key file | ||
| ssl_cert | path name of client public key certificate file | ||
| ssl_ca | path name of Certificate Authority(CA) certificate file | ||
| ssl_capath | path name of directory that contains trusted CA certifcate files | ||
| ssl_cipher | permitted ciphers for SSL encryption |
The SQL query for looking up a user's password hash is mandatory. The query
MUST return a single row only (any other number of rows is considered to be
"user not found"), and it MUST return a single column with only the PBKDF2
password hash. Two '%s' in the auth_opt_userquery string are replaced by the
username attempting to access the broker and the clientid, in that order. If the clientid is not
to be used in the SQL, insert just a single '%s':
SELECT pw FROM users WHERE username = '%s' LIMIT 1The SQL query for checking whether a user is a superuser - and thus
circumventing ACL checks - is optional. If it is specified, the query MUST
return a single row with a single value: 0 is false and 1 is true. We recommend
using a SELECT IFNULL(COUNT(*),0) FROM ... for this query as it satisfies
both conditions. A single '%s' in the auth_opt_superquery string is replaced by the
username attempting to access the broker. The following example uses the
same users table, but it could just as well reference a distinct table
or view.
SELECT IFNULL(COUNT(*), 0) FROM users WHERE username = '%s' AND super = 1The SQL query for checking ACLs is optional, but if it is specified, the
mysql back-end can try to limit access to particular topics or topic branches
depending on the value of a database table. The query MAY return zero or more
rows for a particular user, each containing EXACTLY one column containing a
topic (wildcards are supported). A single '%s' in the query string is
replaced by the username attempting to access the broker, and a single '%d' is
replaced with an integer, 1 signifying a read-only access attempt
(SUB) or 2 signifying a read-write access attempt (PUB).
In the following example, the table has an INT(1) column rw containing 1 for
readonly topics, and 2 for read-write topics:
SELECT topic FROM acls WHERE (username = '%s') AND (rw >= %d)Sample Mosquitto configuration (e.g., mosquitto.conf) for the mysql back-end:
auth_plugin /home/jpm/mosquitto-auth-plug/auth-plug.so
auth_opt_host localhost
auth_opt_port 3306
auth_opt_dbname test
auth_opt_user jjj
auth_opt_pass supersecret
auth_opt_userquery SELECT pw FROM users WHERE username = '%s'
# auth_opt_userquery SELECT pwhash FROM user WHERE username = '%s' AND clientid = '%s'
auth_opt_superquery SELECT COUNT(*) FROM users WHERE username = '%s' AND super = 1
auth_opt_aclquery SELECT topic FROM acls WHERE (username = '%s') AND (rw >= %d)
auth_opt_anonusername AnonymouS
Assuming the following database tables:
mysql> SELECT * FROM users;
+----+----------+---------------------------------------------------------------------+-------+
| id | username | pw | super |
+----+----------+---------------------------------------------------------------------+-------+
| 1 | jjolie | PBKDF2$sha256$901$x8mf3JIFTUFU9C23$Mid2xcgTrKBfBdye6W/4hE3GKeksu00+ | 0 |
| 2 | a | PBKDF2$sha256$901$XPkOwNbd05p5XsUn$1uPtR6hMKBedWE44nqdVg+2NPKvyGst8 | 0 |
| 3 | su1 | PBKDF2$sha256$901$chEZ4HcSmKtlV0kf$yRh2N62uq6cHoAB6FIrxIN2iihYqNIJp | 1 |
+----+----------+---------------------------------------------------------------------+-------+
mysql> SELECT * FROM acls;
+----+----------+-------------------+----+
| id | username | topic | rw |
+----+----------+-------------------+----+
| 1 | jjolie | loc/jjolie | 1 |
| 2 | jjolie | $SYS/something | 1 |
| 3 | a | loc/test/# | 1 |
| 4 | a | $SYS/broker/log/+ | 1 |
| 5 | su1 | mega/secret | 1 |
| 6 | nop | mega/secret | 1 |
+----+----------+-------------------+----+
the above SQL queries would enable the following combinations (the * at
the beginning of the line indicates a superuser)
jjolie PBKDF2$sha256$901$x8mf3JIFTUFU9C23$Mid2xcgTrKBfBdye6W/4hE3GKeksu00+
loc/a DENY
loc/jjolie PERMIT
mega/secret DENY
loc/test DENY
$SYS/broker/log/N DENY
nop <nil>
loc/a DENY
loc/jjolie DENY
mega/secret PERMIT
loc/test DENY
$SYS/broker/log/N DENY
a PBKDF2$sha256$901$XPkOwNbd05p5XsUn$1uPtR6hMKBedWE44nqdVg+2NPKvyGst8
loc/a DENY
loc/jjolie DENY
mega/secret DENY
loc/test PERMIT
$SYS/broker/log/N PERMIT
* su1 PBKDF2$sha256$901$chEZ4HcSmKtlV0kf$yRh2N62uq6cHoAB6FIrxIN2iihYqNIJp
loc/a PERMIT
loc/jjolie PERMIT
mega/secret PERMIT
loc/test PERMIT
$SYS/broker/log/N PERMIT
The mysql back-end will re-connect to the MySQL server when the connection has been lost.
If you wish, you can disable this by configuring:
auth_opt_mysql_opt_reconnect false
auth_opt_mysql_auto_connect false
The LDAP plugin currently does authentication only; authenticated users are allowed to publish/subscribe at will.
The user that connects to the broker is searched for in the LDAP directory indicated
via the ldap_uri configuration parameter. This LDAP search MUST return exactly one
entry. The user's password is then used with the DN of the that entry to bind to the
directory. If that LDAP bind succeeds, the user is authenticated. In all other cases,
authentication fails.
| Option | default | Mandatory | Meaning |
|---|---|---|---|
| binddn | Y | the DN of an object which may search users | |
| bindpw | Y | its password | |
| ldap_uri | Y | an LDAP uri with filter | |
| ldap_acl_deny | false | return DENY instead of ALLOW to ACL checks |
Example configuration:
auth_plugin /path/to/auth-plug.so
auth_opt_backends ldap
auth_opt_binddn cn=manager,dc=mens,dc=de
auth_opt_bindpw s3crit
auth_opt_ldap_uri ldap://127.0.0.1/ou=Users,dc=mens,dc=de?cn?sub?(&(objectclass=inetOrgPerson)(uid=@))
auth_opt_ldap_acl_deny false
With the ldap_acl_deny we return DENY instead of ALLOW for every ACL check. This makes it possible to chain other backends with ldap backend, and use LDAP for authentification and, e.g., MySQL for ACL checking.
| Option | default | Mandatory | Meaning |
|---|---|---|---|
| cdbname | Y | path to .cdb |
| Option | default | Mandatory | Meaning |
|---|---|---|---|
| dbpath | Y | path to database | |
| sqliteuserquery | Y | SQL for users |
Example:
auth_opt_sqliteuserquery SELECT pw FROM users WHERE username = ?
auth_opt_redis_userquery GET %s
auth_opt_redis_aclquery GET %s-%s
In auth_opt_redis_userquery the %s parameter is the username, whereas in auth_opt_redis_aclquery, the first %s is the username and the second is the topic. When using ACLs, topic must be an exact match - wildcards are not supported.
If no options are provided, then the plugin will default to not using an ACL and using the above userquery.
| Option | default | Mandatory | Meaning |
|---|---|---|---|
| redis_host | localhost | hostname / IP address | |
| redis_port | 6379 | TCP port number |
The http back-end is for auth by custom HTTP API.
The following auth_opt_ options are supported by the http back-end:
| Option | default | Mandatory | Meaning |
|---|---|---|---|
| http_ip | Y | IP address, will skip DNS lookup | |
| http_port | 80 | TCP port number | |
| http_hostname | hostname for HTTP header | ||
| http_getuser_uri | Y | URI for checking username/password | |
| http_superuser_uri | Y | URI for checking superuser | |
| http_aclcheck_uri | Y | URI for checking acl | |
| http_with_tls | false | Use TLS on connect | |
| http_basic_auth_key | Basic Authentication Key | ||
| http_retry_count | 3 | Number of retries done if backend is unavailable |
If the configured URLs return an HTTP status code == 2xx, the authentication /
authorization succeeds. If the status code == 4xx, authentication /
authorization fails. For a status code == 5xx or server Unreachable, the HTTP request
will be retried up to http_retry_count. If all tries fail and if no other backend succeeded,
then an error is returned and the client is disconnected.
| URI-Param | username | password | clientid | topic | acc |
|---|---|---|---|---|---|
| http_getuser_uri | Y | Y | N | N | N |
| http_superuser_uri | Y | N | N | N | N |
| http_aclcheck_uri | Y | N | Y | Y | Y |
Mosquitto configuration for the http back-end:
auth_opt_backends http
auth_opt_http_ip 127.0.0.1
auth_opt_http_port 8089
#auth_opt_http_hostname example.org
auth_opt_http_getuser_uri /auth
auth_opt_http_superuser_uri /superuser
auth_opt_http_aclcheck_uri /acl
A very simple example service using Python and bottle can be found in examples/http-auth-be.py.
The http plugin can utilize environment variables which are exported before it (i.e., Mosquitto) is started by adding configuration settings like
auth_opt_<interface>_<method>_params <key>=<evn_name>[,<key>=<evn_name>]*
For example, set the following:
export DOMAIN=example.com
export PORT=8080and add the following settings to mosquitto.conf:
auth_opt_http_getuser_params domain=DOMAIN,port=PORT
auth_opt_http_superuser_params domain=DOMAIN,port=PORT
auth_opt_http_aclcheck_params domain=DOMAIN,port=PORT
The jwt back-end is for auth by JWT-webtokens. The JWT and HTTP configurations are identical, so please read the http-section above.
The username field is interpreted as the token-field and passed to the http-server in an Authorization-header.
Authorization: Bearer %token
Note: Some clients require the password field to be populated. This field is ignored by the JWT-backend, so feel free to input some gibberish.
The postgres back-end, like mysql, is currently the most feature-complete: it supports
distinct SQL queries for obtaining passwords, checking for superusers, and verifying ACLs,
each configurable to suit your schema.
The following auth_opt_ options are supported by the postgres back-end:
| Option | default | Mandatory | Meaning |
|---|---|---|---|
| host | localhost | hostname/address | |
| port | 5432 | TCP port | |
| user | username | ||
| pass | password | ||
| dbname | Y | database name | |
| userquery | Y | SQL for users | |
| superquery | SQL for superusers | ||
| aclquery | SQL for ACLs | ||
| sslcert | SSL/TLS Client Cert. | ||
| sslkey | SSL/TLS Client Cert. Key |
The SQL query for looking up a user's password hash is mandatory. The query
must return a single row only (any other number of rows is considered to be
"user not found"), and it must return a single column only with the PBKDF2
password hash. A single $1 in the query string is replaced by the
username attempting to access the broker.
SELECT pass FROM account WHERE username = $1 limit 1The SQL query for checking whether a user is a superuser - and thus
circumventing ACL checks - is optional. If it is specified, the query must
return a single row with a single value: 0 is false and 1 is true. We recommend
using a SELECT COALESCE(COUNT(*),0) FROM ... for this query as it satisfies
both conditions. A single $1 in the auth_opt_superquery string is replaced by the
username attempting to access the broker. The following example uses the
same account table, but it could just as well reference a distinct table
or view.
SELECT COALESCE(COUNT(*),0) FROM account WHERE username = $1 AND super = 1The SQL query for checking ACLs is optional, but if it is specified, the
postgres back-end can try to limit access to particular topics or topic branches
depending on the value of a database table. The query MAY return zero or more
rows for a particular user, each containing EXACTLY one column containing a
topic (wildcards are supported). A single $1 in the query string is
replaced by the username attempting to access the broker, and a single $2 is
replaced with an integer, 1 signifying a read-only access attempt
(SUB) or 2 signifying a read-write access attempt (PUB).
In the following example, the table has a column rw containing 1 for
readonly topics, 2 for writeonly topics and 3 for readwrite topics:
SELECT topic FROM acl WHERE (username = $1) AND rw >= $2Sample Mosquitto configuration for the postgres back-end:
auth_plugin /home/jpm/mosquitto-auth-plug/auth-plug.so
auth_opt_host localhost
auth_opt_port 5432
auth_opt_dbname test
auth_opt_user jjj
auth_opt_pass supersecret
auth_opt_userquery SELECT pw FROM account WHERE username = $1 limit 1
auth_opt_superquery SELECT COALESCE(COUNT(*),0) FROM account WHERE username = $1 AND mosquitto_super = 1
auth_opt_aclquery SELECT topic FROM acls WHERE (username = $1) AND (rw & $2) > 0
auth_opt_sslcert /etc/postgresql/ssl/client.crt
auth_opt_sslkey /etc/postgresql/ssl/client.key
Assuming the following database tables:
=> SELECT * FROM account;
+----+----------+---------------------------------------------------------------------+-------+
| id | username | pw | super |
+----+----------+---------------------------------------------------------------------+-------+
| 1 | jjolie | PBKDF2$sha256$901$x8mf3JIFTUFU9C23$Mid2xcgTrKBfBdye6W/4hE3GKeksu00+ | 0 |
| 2 | a | PBKDF2$sha256$901$XPkOwNbd05p5XsUn$1uPtR6hMKBedWE44nqdVg+2NPKvyGst8 | 0 |
| 3 | su1 | PBKDF2$sha256$901$chEZ4HcSmKtlV0kf$yRh2N62uq6cHoAB6FIrxIN2iihYqNIJp | 1 |
+----+----------+---------------------------------------------------------------------+-------+
=> SELECT * FROM acls;
+----+----------+-------------------+----+
| id | username | topic | rw |
+----+----------+-------------------+----+
| 1 | jjolie | loc/jjolie | 1 |
| 2 | jjolie | $SYS/something | 1 |
| 3 | a | loc/test/# | 1 |
| 4 | a | $SYS/broker/log/+ | 1 |
| 5 | su1 | mega/secret | 1 |
| 6 | nop | mega/secret | 1 |
+----+----------+-------------------+----+
the above SQL queries would enable the following combinations (the * at
the beginning of the line indicates a superuser)
jjolie PBKDF2$sha256$901$x8mf3JIFTUFU9C23$Mid2xcgTrKBfBdye6W/4hE3GKeksu00+
loc/a DENY
loc/jjolie PERMIT
mega/secret DENY
loc/test DENY
$SYS/broker/log/N DENY
nop <nil>
loc/a DENY
loc/jjolie DENY
mega/secret PERMIT
loc/test DENY
$SYS/broker/log/N DENY
a PBKDF2$sha256$901$XPkOwNbd05p5XsUn$1uPtR6hMKBedWE44nqdVg+2NPKvyGst8
loc/a DENY
loc/jjolie DENY
mega/secret DENY
loc/test PERMIT
$SYS/broker/log/N PERMIT
* su1 PBKDF2$sha256$901$chEZ4HcSmKtlV0kf$yRh2N62uq6cHoAB6FIrxIN2iihYqNIJp
loc/a PERMIT
loc/jjolie PERMIT
mega/secret PERMIT
loc/test PERMIT
$SYS/broker/log/N PERMIT
Note that the above sample auth_opt_aclquery is sensitive to new permission values used in Mosquitto 1.5.
You can either adapt to the updated binary-style permissions
(2 for write, 5 for read+subscribe, 7 for read/write),
modify your query to work around them, or modify the constants in the Mosquitto source.
The mongo back-end works with superuser and ACL checks. Additional build dependencies are https://github.com/mongodb/mongo-c-driver >=1.4.0
and https://github.com/mongodb/libbson >=1.4.0.
You should set up a users collection (required) and a topic lists collection (optional) with the following format:
Each user document must have a username, a hashed password, and at least one of:
- A superuser prop, allowing full access to all topics
- An embedded array or sub-document to use as an ACL (see 'ACL format')
- A foreign key pointing to another document containing an ACL (see 'ACL format')
You may use any combination of these options; authorisation will be granted if any check passes.
The user document has the following format (note that the property names are configurable variables, see 'Configuration').
{
[user_username_prop]: string, // Username as given in the MQTT connect request
[user_password_prop]: string, // A PBKDF2 hash, see 'Passwords' section
[user_topiclist_fk_prop]: int | oid | string, // reference to a document in collection_topics)
[user_topics_prop]: string[] | { [topic: string]: "r"|"w"|"rw" }, // see 'ACL format'
[user_superuser_prop]: int | boolean // optional, superuser if truthy
}
As an example using default options, a user document with an embedded ACL might look like:
{
"username": "user1",
"password": "PBKDF2$sha256$901$8ebTR72Pcmjl3cYq$SCVHHfqn9t6Ev9sE6RMTeF3pawvtGqTu",
"superuser": false,
"topics": {
"public/#": "r",
"client/user1/#": "rw"
}
}If the user document references a separate topics document, that document should exist and must have the format:
{
[topiclist_key_prop]: int | oid | string, // unique id, as referenced by users[user_topiclist_fk_prop],
[topiclist_topics_prop]: string[] | { [topic: string]: "r"|"w"|"rw" } // see 'ACL format'
}
This strategy will be especially suitable if you have a complex ACL shared between many users.
Topics may be given as either an array of topic strings, eg ["topic1/#", "topic2/+"], in which case all topics will
be read-write, or as a sub-document mapping topic names to the strings "r", "w", "rw", eg
{ "article/#":"r", "article/+/comments":"rw", "ballotbox":"w" }.
The following auth_opt_mongo_ options are supported by the mongo back-end:
| Option | default | Meaning |
|---|---|---|
| uri | mongodb://localhost:27107 | MongoDB connection string (database part is ignored) |
| database | mqGate | Name of the database containing users (and topiclists) |
| user_coll | users | Collection for user documents |
| topiclist_coll | topics | Collection for topiclist documents (optional if embedded topics are used) |
| user_username_prop | username | Username property name in the user document |
| user_password_prop | password | Password property name in the user document |
| user_superuser_prop | superuser | Superuser property name in the user document |
| user_topics_prop | topics | Name of a property on the user document containing an embedded topic list |
| user_topiclist_fk_prop | topics | Property used as a foreign key to reference a topiclist document |
| topiclist_key_prop | _id | Unique key in the topiclist document pointed to by user_topiclist_fk_prop |
| topiclist_topics_prop | topics | Property containing topics within the topiclist document |
Mosquitto configuration for the mongo back-end:
auth_plugin /home/jpm/mosquitto-auth-plug/auth-plug.so
auth_opt_mongo_uri mongodb://localhost:27017
The files backend attempts to re-implement the files behavior in vanilla Mosquitto, however the user's password file contains PBKDF2 passwords instead of passwords hashed with the mosquitto-passwd program; you would use our np utility or similar to create the PBKDF2 hashes.
The configuration directives for the Files backend are as follows:
auth_opt_backends files
auth_opt_password_file file.pw
auth_opt_acl_file file.acl
with examples of these files being:
# comment
jpm:PBKDF2$sha256$901$UGfDz79cAaydRsEF$XvYwauPeviFd1NfbGL+dxcn1K7BVfMeW
jane:PBKDF2$sha256$901$wvvH0fe7Ftszt8nR$NZV6XWWg01dCRiPOheVNsgMJDX1mzd2v
user jane
topic read #
user jpm
topic dd
The syntax for the ACL file is that as described in mosquitto.conf(5).
If Mosquitto has been built with PSK support, and auth-plug has been built
with BE_PSK defined, it supports authenticating PSK connections over TLS, as
long as Mosquitto is appropriately configured.
The way this works is that the psk back-end actually uses one of auth-plug's
other databases (mysql, sqlite, cdb, etc.) to obtain the pre-shared key
from the "users" query, and it uses the same database's back-end for performing
authorization (aka ACL checks).
Consider the following mosquitto.conf snippet:
...
auth_opt_psk_database mysql
...
listener 8885
psk_hint hint1
tls_version tlsv1
use_identity_as_username true
TLS PSK is available on port 8885 and is activated with, say,
mosquitto_pub -h localhost -p 8885 -t x -m hi --psk-identity ps2 --psk 020202
The use_identity_as_username option has auth-plug see the name ps2 as the
username, and this is given to the database back-end (here: mysql) to look up
the password as defined for the mysql back-end. auth-plug uses its getuser() query
to read the clear-text (not PKBDF2) hex key string which it returns to Mosquitto
for authentication. If authentication passes, the connection is established.
For authorization, auth_plug uses the identity as the username and the topic to perform ACL-checking as described earlier.
The following log-snippet serves as an illustration:
New connection from ::1 on port 8885.
|-- psk_key_get(hint1, ps1) from [mysql] finds PSK: 1
New client connected from ::1 as mosqpub/90759-tiggr.ww. (c1, k60).
Sending CONNACK to mosqpub/90759-tiggr.ww. (0)
|-- user ps1 was authenticated in back-end 0 (psk)
|-- mysql: topic_matches(x, x) == 1
|-- aclcheck(ps1, x, 2) AUTHORIZED=1 by psk
Received PUBLISH from mosqpub/90759-tiggr.ww. (d0, q0, r0, m0, 'x', ... (2 bytes))
Received DISCONNECT from mosqpub/90759-tiggr.ww.
In the case of this MySQL example, we added the clear text of the PSK key to the database:
mysql> INSERT INTO user (username, pwhash, superuser) VALUES ('mylistener', 'F0BEEF', 0);
A user's password is stored as a PBKDF2 hash in the back-end. An example
"password" is a string with five pieces in it, delimited by $, inspired by
this.
PBKDF2$sha256$901$8ebTR72Pcmjl3cYq$SCVHHfqn9t6Ev9sE6RMTeF3pawvtGqTu
--^--- --^--- -^- ------^--------- -------------^------------------
| | | | |
| | | | +-- : hashed password
| | | +-------------------------- : salt
| | +----------------------------------- : iterations
| +----------------------------------------- : hash function
+------------------------------------------------ : marker
Note that the salt by default will be taken as-is (thus it will not be
base64 decoded before the validation). In case your own implementation uses
the raw bytes when hashing the password and base64 is only used for display
purpose, compile this project with the -DRAW_SALT flag (you could add this
in the config.mk file to CFG_CFLAGS).
A trivial utility to generate hashes is included as np. Copy and paste the
whole string generated into the respective back-end.
$ np
Enter password:
Re-enter same password:
PBKDF2$sha256$901$Qh18ysY4wstXoHhk$g8d2aDzbz3rYztvJiO3dsV698jzECxSgFor example, in Redis:
$ redis-cli
> SET n2 PBKDF2$sha256$901$Qh18ysY4wstXoHhk$g8d2aDzbz3rYztvJiO3dsV698jzECxSg
> QUIT
listener 1883
auth_plugin /path/to/auth-plug.so
auth_opt_redis_host 127.0.0.1
auth_opt_redis_port 6379
# Usernames with this fnmatch(3) (a.k.a glob(3)) pattern are exempt from the
# module's ACL checking
auth_opt_superusers S*
In addition to the ACL checking which might be performed by a back-end,
there's a more "static" checking which can be configured in mosquitto.conf.
Note that if ACLs are being verified by the plugin, this also applies to Will topics (last will and testament). Failing to correctly set up an ACL for these, will cause a broker to silently fail with a 'not authorized' message.
Users can be given "superuser" status (i.e. they may access any topic)
if their username matches the glob specified in auth_opt_superusers.
In our example above, any user with a username beginning with a capital "S"
is exempt from ACL-checking.
At this point you ought to be able to connect to Mosquitto using, e.g., the Mosquitto client:
mosquitto_pub -t '/location/n2' -m hello -u n2 -P secret
- A Mosquitto broker
- OpenSSL (tested with 1.0.0c, but should work with earlier versions)
Some of the back-ends require a server instance or client libraries. For example:
- for redis: a Redis server and hiredis, the Minimalistic C client for Redis
- for cdb: TinyCDB by Michael Tokarev (included in
contrib/) - for postgres: the latest
devversion ofpostgresql-server
- Uses
base64.[ch](and yes, I know OpenSSL has base64 routines, but no thanks). These files are
Copyright (c) 1995, 1996, 1997 Kungliga Tekniska Hgskolan (Royal Institute of Technology, Stockholm, Sweden).
- Uses uthash by Troy D. Hanson.
- docker-mosquitto - easy installation of this plugin
- mosquitto_pyauth
- mosquitto-auth-plugin-http
- lua_auth_plugin