Authentication / Authorization Incompatibility Between EMQX 4.4 and EMQX 5.1

This page presents the compatibility information for authentication and authorization configurations between EMQX 4.4 and EMQX 5.1.

Common Incompatibility Changes

SSL Options

EMQX 5.1 provides the option of enabling TLS when there is a need to access external resources, such as connecting to a database (MySQL, PostgreSQL, MongoDB, Redis) for authentication, or using password-based authentication with access to a web server via HTTPS. For more information, refer to TLS for External Resource Access.

Placeholders

Backends that support some kind of data interpolation (MySQL, PostgreSQL, MongoDB, Redis, HTTP for external requests, JWT for data interpolation) now use ${variable} placeholders instead of %X ones.

Authentication

Common Changes (All Authentication Sources)

Password Hashing

All password-based providers (Built-in database, MySQL, PostgreSQL, MongoDB, Redis) now have the same password_hash options, configured in the same way. For details, refer to Password Hashing.

Per-Listener Authentication

Unlike in version 4.4, each MQTT listener in EMQX 5.1 may have its own authentication configuration. Additionally, the enable_authn listener option is available:

• enable_authn=true is the default, delegating authentication to the authentication chain.
• enable_authn=false completely disables authentication for the listener.
• enable_authn=quick_deny_anonymous is similar to true, but also immediately rejects connecting clients without credentials.

Remove the Anonymous Mechanism

EMQX 5.1 no longer has explicit allow_anonymous settings. All clients are allowed to connect by default. If you add and enable any authenticator, EMQX will try to authenticate the clients. To allow anonymous access, remove or disable all authenticators in the global or listener-specific chain.

After traversing the configured authentication chain, if none of the authenticator in the chain can decide that this client is allowed to connect, then the connection is rejected.

The bypass_auth_plugins configuration is also deleted. When you wants to allow all clients to connect without authentication, you can set listeners.{type}.{name}.enable_authn = false.

Built-in Database (Mnesia)

• Mnesia is now referred to as the "built-in" database; No user records in the configuration.
• Change password_hash to password_hash_algorithm: {name = Algo, salt_position = prefix}. For details, refer to Password Hashing.
• user_id_type is used to identify whether the clientid or username should be used as MQTT user identifiers. Mixed types of records are not allowed.
• The REST APIs to manage the authentication data records are changed. For more information, refer to the API doc for POST /authentication/{id}/users.
• Users can use the data import API to import data from older versions into EMQX 5.x, see POST /authentication/{id}/import_users for details.

Example

EMQX 4.4

auth.mnesia.password_hash = sha256

EMQX 5.1

authentication {
   backend = built_in_database
   mechanism = password_based
   password_hash_algorithm {
      name = sha256
      salt_position = prefix
   }
   user_id_type = username
   enable = true
}

Built-in Database (Enhanced Authentication)

• SHA1 hashing support used in EMQX 4.4 is no longer available. Use the algorithm parameter to choose between sha512'and sha256 algorithms.
• iteration_count can now be configured to specify the calculation times of hash function (4096 was implicitly used in EMQX 4.4).

Example

EMQX 4.4

# No configuration

EMQX 5.1

{
    mechanism = scram
    backend = built_in_database
    enable = true

    algorithm = sha512
    iteration_count = 4096
}

Redis

  mechanism = password_based
  backend = redis

• type is changed to redis_type.

  • For type single, server is changed to servers.
  • For type sentinel, server is changed to servers.
  • For type cluster, database option is no longer available.

• database is still database (except for the cluster type); this option is no more applicable for cluster type.

• pool is changed to pool_size.

• password is still password.

• query_timeout is no longer used.

• ssl.* options are changed to common SSL options. Refer to TLS for External Resource Access.

• auth_cmd is changed to cmd. Only supports Redis Hashes data structure and HGET and HMGET query commands. Use ${var}-style placeholders in the command. The command should fetch at least the password (compatible with 4.x) or password_hash field and optionally the salt and is_superuser fields.

• super_cmd is no longer used. Provide the is_superuser field in cmd instead. If you need to give clients super-user permissions, please add the is_superuser field to the Redis query command.

  Details

  # bad
  GET emqx_user:${username}
  # bad
  HMGET emqx_user:${username} passwd
  
  # good
  HMGET emqx_user:${username} password_hash
  
  # good
  HMGET emqx_user:${username} password_hash is_superuser

• password_hash now uses common password_hash_algorithm parameters.

You can use auto_reconnect to automatically reconnect to Redis on failure.

Example

EMQX 4.4

auth.redis.type = single
auth.redis.server = 127.0.0.1:6379
auth.redis.pool = 8
auth.redis.database = 0
auth.redis.password = pass
assword salt
auth.redis.auth_cmd = HMGET mqtt_user:%u password salt

auth.redis.password_hash = salt,sha256

auth.redis.ssl = on
auth.redis.ssl.cacertfile = path/to/your/cafile.pem
auth.redis.ssl.certfile = path/to/your/certfile
auth.redis.ssl.keyfile = path/to/your/keyfile
auth.redis.ssl.verify = true
auth.redis.ssl.server_name_indication = myredis

EMQX 5.1

authentication {
  mechanism = password_based
  backend = redis
  enable = true

  redis_type = single
  server = "127.0.0.1:6379"

  password_hash_algorithm {
      name = sha256
      salt_position = prefix
  }

  cmd = "HMGET mqtt_user:${username} password salt"
  database = 0
  password = "pass"
  auto_reconnect = true
  ssl {
    enable = true
    verify = verify_peer
   
    keyfile = path/to/your/keyfile
    certfile = path/to/your/certfile
    cacertfile = path/to/your/cafile.pem
    
    server_name_indication = myredis
  }
}

MySQL

  backend = mysql
  mechanism = password_based

• server, username, password, database, query_timeout are retained.

• pool is changed to pool_size.

• ssl.* options are changed to common SSL options. Refer to TLS for External Resource Access.

• password_hash is changed tocommon password_hash_algorithm parameters.

• auth_query is changed to query. ${var}-style placeholders should be used. Query should fetch at least password or password_hash column and optionally salt and is_superuser columns.

• super_query is not used anymore, is_superuser column is provided in query instead. If you need to give clients super-user permissions, please ensure that the authentication SQL result contains the is_superuser field.

  SELECT
    password as password_hash,
    salt,
    is_superuser
  FROM mqtt_user
    where username = ${username} LIMIT 1

You can use auto_reconnect to reconnect to MySQL automatically on failure.

Example

EMQX 4.4

auth.mysql.server = 127.0.0.1:3306
auth.mysql.pool = 8
auth.mysql.username = dbuser
auth.mysql.database = mqtt

auth.mysql.query_timeout = 5s

auth.mysql.auth_query = select password_hash as password from mqtt where username = '%u' limit 1
auth.mysql.super_query = select is_superuser from mqtt where username = '%u' limit 1

auth.mysql.ssl = on
auth.mysql.ssl.cacertfile = path/to/your/cafile.pem
auth.mysql.ssl.certfile = path/to/your/certfile
auth.mysql.ssl.keyfile = path/to/your/keyfile
auth.mysql.ssl.verify = true
auth.mysql.ssl.server_name_indication = mymysql

EMQX 5.1

authentication {
  backend = mysql
  mechanism = password_based
  
  enable = true

  server = "127.0.0.1:3306"
  username = "dbuser"
  database = "mqtt"
  password = "dbpass"
  pool_size = 8

  password_hash_algorithm {
      name = sha256
      salt_position = prefix
  }

  query = "SELECT password_hash, salt, is_superuser FROM mqtt where username = ${username} LIMIT 1"
  query_timeout = "5s"
  
  auto_reconnect = true
  ssl {
    enable = true
    verify = verify_peer
   
    keyfile = path/to/your/keyfile
    certfile = path/to/your/certfile
    cacertfile = path/to/your/cafile.pem
    
    server_name_indication = mymysql
  }
}

PostgreSQL

  mechanism = password_based
  backend = postgresql

• server, username, password, database are retained.

• query_timeout is not used anymore.

• encoding is not used anymore.

• pool is changed to pool_size.

• ssl.* is changed to common SSL options. Refer to TLS for External Resource Access.

• password_hash is changed to common password_hash_algorithm parameters.

• auth_query is changed to query. ${var}-style placeholders should be used. Query should fetch at least password or password_hash column and optionally salt and is_superuser columns.

• super_query is not used anymore, is_superuser column is provided in the query instead. If you need to give clients super-user permissions, please ensure that the authentication SQL result contains the is_superuser field.

  SELECT
    password as password_hash,
    salt,
    is_superuser
  FROM mqtt_user
    where username = ${username} LIMIT 1

Example

EMQX 4.4

auth.pgsql.server = 127.0.0.1:5432
auth.pgsql.pool = 8
auth.pgsql.username = root
auth.pgsql.password = dbpass

auth.pgsql.database = mqtt
auth.pgsql.encoding = utf8

auth.pgsql.auth_query = select password, salt from mqtt_user where username = '%u' limit 1
auth.pgsql.password_hash = salt,sha256
auth.pgsql.super_query = select is_superuser from mqtt_user where username = '%u' limit 1

auth.pgsql.ssl = on
auth.pgsql.ssl.cacertfile = path/to/your/cafile.pem
auth.pgsql.ssl.certfile = path/to/your/certfile
auth.pgsql.ssl.keyfile = path/to/your/keyfile
auth.pgsql.ssl.verify = true
auth.pgsql.ssl.server_name_indication = mypgsql

EMQX 5.1

authentication {
  backend = postgresql
  mechanism = password_based
  
  enable = true

  server = "127.0.0.1:5432"
  username = "root"
  database = "mqtt"
  password = "dbpass"
  pool_size = 8

  password_hash_algorithm {
      name = sha256
      salt_position = prefix
  }

  query = "SELECT password_hash, salt, is_superuser FROM mqtt_user where username = ${username} LIMIT 1"
  
  auto_reconnect = true
  ssl {
    enable = true
    verify = verify_peer
   
    keyfile = path/to/your/keyfile
    certfile = path/to/your/certfile
    cacertfile = path/to/your/cafile.pem
    
    server_name_indication = mypgsql
  }
}

MongoDB

mechanism = password_based
backend = mongodb

• type is changed to mongo_type field. Possible values are single, rs, sharded. Unknown value is not available anymore.

• server

  • For rs, sharded to servers
  • For single to server

• srv_record, username, password, auth_source, database, w_mode, topology, collection are retained.

• r_mode is availalable only for rs type.

• pool is changed to pool_size.

• ssl.* is changed to common SSL options. Refer to TLS for External Resource Access.

• auth_query.selector is changed to filter. The filter should not be a string, but the whole selector data structure. ${var}-style placeholders may be used in selector values.

• auth_query.salt_field is changed to salt_field.

• auth_query.super_field is changed to is_superuser_field.

• super_query is not used anymore. Provide is_superuser_field field in the documents fetched with filter together with is_superuser_field setting.

  Details

  authentication = [
    {
      ...
      mechanism = "password_based"
      backend = "mongodb"
      # is_superuser_field = "is_superuser"
    }
  ]

• password_hash is changed to common password_hash_algorithm parameters.

• query_timeout is not used.

Example

EMQX 4.4

auth.mongo.type = single
auth.mongo.srv_record = false
auth.mongo.server = 127.0.0.1:27017
auth.mongo.pool = 8
auth.mongo.username = user
auth.mongo.password = pass
auth.mongo.auth_source = admin
auth.mongo.database = mqtt
auth.mongo.query_timeout = 5s

auth.mongo.ssl = on
auth.mongo.ssl.cacertfile = path/to/your/cafile.pem
auth.mongo.ssl.certfile = path/to/your/certfile
auth.mongo.ssl.keyfile = path/to/your/keyfile
auth.mongo.ssl.verify = true
auth.mongo.ssl.server_name_indication = mymongo

auth.mongo.w_mode = unsafe

auth.mongo.topology.pool_size = 1
auth.mongo.topology.max_overflow = 0

## auth.mongo.auth_query.password_hash = salt,sha256

auth.mongo.auth_query.collection = mqtt_user
auth.mongo.auth_query.password_field = password_hash

auth.mongo.auth_query.selector = username=%u, clientid=%c

auth.mongo.super_query.collection = mqtt_user
auth.mongo.super_query.super_field = is_superuser
auth.mongo.super_query.selector = username=%u, clientid=%c

EMQX 5.1

authentication {
  mechanism = password_based
  backend = mongodb
  enable = true

  password_hash_algorithm {
    name = sha256
    salt_position = prefix
  }

  collection = "mqtt_user"
  filter { username = "${username}", clientid = "${clientid}" }
  
  password_hash_field = "password_hash"
  salt_field = "salt"
  is_superuser_field = "is_superuser"

  mongo_type = single
  server = "127.0.0.1:27017"

  database = "mqtt"
  username = "emqx"
  password = "pass"
  
  ssl {
    enable = true
    verify = verify_peer
   
    keyfile = path/to/your/keyfile
    certfile = path/to/your/certfile
    cacertfile = path/to/your/cafile.pem
    
    server_name_indication = mymongo
  }
  
  topology {
    pool_size = 1
    max_overflow = 0
  }
}

JWT

mechanism = jwt

• secret, from, verify_claims, acl_claim_name, refresh_interval are retained.
• pubkey is changed to public_key.
• jwks is changed to endpoint.
• signature_format is no more available.

In verifiy_claims, ${var}-style placeholders (${username} and ${clientid}) should be used in selector values instead of %X ones.

Additional parameters:

• use_jwks: whether to fetch keys from JWKS
• algorithm: public-key|hmac-based which type of signature to verify.
• secret_base64_encoded: specifies secret format
• pool_size: number of connections to JWKS server
• ssl SSL options for connecting to JWKS server

Not all sets of parameters are allowed.

EMQX 4.x supports public key and hmac secret algorithms, as well as jwks at the same time. Unlike EMQX 4.4, not all combinations of (secret, secret_base64_encoded,public_key, endpoint, pool_size, refresh_interval , ssl ) parameters are allowed. EMQX 5.1 uses one algorithm at a time only, which is set in the global config. use_jwks and algorithm identify the available sets:

With use_jwks=true and algorithm=public-key: endpoint, pool_size,``refresh_interval, ssl`

With use_jwks=false and algorithm=public-key: public_key

With use_jwks=false and algorithm=hmac-based: secret, secret_base64_encoded

Combination use_jwks=true and algorithm=hmac-based is invalid.

Example

EMQX 4.4

auth.jwt.jwks = https://127.0.0.1:8080/jwks
auth.jwt.jwks.refresh_interval = 5m
auth.jwt.from = password

auth.jwt.verify_claims = on

auth.jwt.verify_claims.username = %u

auth.jwt.acl_claim_name = acl

EMQX 5.1

{
  mechanism = jwt
  from = password,
  acl_claim_name = acl
  use_jwks = true
  algorithm = "public-key"
  verify_claims = {
    username = "${username}
  }
  
  ssl {
    enable = true
  }
  
  endpoint = "https://127.0.0.1:8080/jwks"
}

HTTP

mechanism = password_based
backend = http

• method, pool_size, connect_timeout, and enable_pipelining are retained.
• auth_req.url is changed to url.
• auth_req.headers is changed to headers.
• auth_req.params is changed with body.
• timeout is changed to request_timeout.
• ssl.* is changed to common SSL options. Refer to TLS for External Resource Access.
• super_req is not available. Provide is_superuser field in the service response instead.

Unlike version 4.4, url, headers, and body parameters allow placeholders. In version 5.1, body is not a string, but a map. It is serialized using JSON or X-WWW-Form-Urlencoded format (for post requests) or as query params (for get requests).

Unlike version 4.4, HTTP authentication only respects responses with successful HTTP code (2XX) and takes the resolution from the response body (from result) field. In version 5.1, the authentication result is now determined through JSON fields within the response body, rather than utilizing HTTP response status codes.

Details

Success response status code:

200 or 204

The authenticator will be ignored if the request fails or returns another status code.

Success response body (JSON):

Name	Type	Required	Description
result	Enum	true	`allow
is_supseruser	Boolean	false

{
  "result": "allow",
  "is_supseruser": true
}

Example

EMQX 4.4

auth.http.auth_req.url = http://127.0.0.1:80/mqtt/auth
auth.http.auth_req.method = post
auth.http.auth_req.headers.content_type = application/x-www-form-urlencoded

auth.http.auth_req.params = clientid=%c,username=%u,password=%P

auth.http.timeout = 5s

auth.http.connect_timeout = 5s
auth.http.pool_size = 32

auth.http.enable_pipelining = 100

auth.http.ssl = on
auth.http.ssl.cacertfile = path/to/your/cafile.pem
auth.http.ssl.certfile = path/to/your/certfile
auth.http.ssl.keyfile = path/to/your/keyfile
auth.http.ssl.verify = true
auth.http.ssl.server_name_indication = myhttp

EMQX 5.1

{
    mechanism = password_based
    backend = http
    enable = true

    method = post
    url = "http://127.0.0.1:80/mqtt/auth"
    body {
        username = "${username}"
        clientid = "${clientid}"
        password = "${password}"
    }
    headers {
        "Content-Type" = "application/x-www-form-urlencoded"
    }
    request_timeout = "5s"
    connect_timeout = "5s"
    pool_size = 32
    
    enable_pipelining = 100
    
    ssl {
      enable = true
      verify = verify_peer
    
      keyfile = path/to/your/keyfile
      certfile = path/to/your/certfile
      cacertfile = path/to/your/cafile.pem
      
      server_name_indication = myhttp
    } 
}

Authorization

ACL File

1. Removed the acl_file configuration. The file-based ACL (acl.conf) will be used as one of the authorization sources and added to EMQX by default.
2. acl.conf data file syntax has been changed.
3. In dsl, pubsub is renamed to all.

4.x	5.1	Compatibility
user	username	Yes
client	clientid	Yes
pubsub	all	No

Example

EMQX 4.3

{allow, {user, "dashboard"}, subscribe, ["$SYS/#"]}.

{allow, {ipaddr, "127.0.0.1"}, pubsub, ["$SYS/#", "#"]}.

{deny, all, subscribe, ["$SYS/#", {eq, "#"}]}.

{allow, all}.

EMQX 5.1

{allow, {user, "dashboard"}, subscribe, ["$SYS/#"]}.

{allow, {ipaddr, "127.0.0.1"}, all, ["$SYS/#", "#"]}.

{deny, all, subscribe, ["$SYS/#", {eq, "#"}]}.

{allow, all}.

Built-in Database

• Mnesia renamed to the Built-in Database.
• The data format and REST API have changed. 4.x ACL data can be exported with ./bin/emqx_ctl data export command. Users may convert the data into 5.x format and import it through the corresponding REST API /authorization/sources/built_in_database/rules/{clients,users}.

Example

EMQX 4.4

# No settings

EMQX 5.1

{
  type = built_in_database
  enable = true
}

JWT

This is the implicit ACL based on claims fetched during JWT authentication. In ACL claims, ${variable} placeholders instead of %X ones should be used.

HTTP

type = http

• method, pool_size, connect_timeout, enable_pipelining are retained.
• acl_req.url is changed to url.
• acl_req.headers is changed to headers.
• acl_req.params is changed to body.
• timeout to request_timeout.
• ssl.* is changed to common SSL options. Refer to TLS for External Resource Access.

Unlike 4.4, url, headers, and body parameters allow placeholders.

In 5.1, body is not a string, but a map. It is serialized using JSON or X-WWW-Form-Urlencoded format (for post requests) or as query params (for get requests).

Unlike 4.4, the authorization result is now determined through JSON fields within the response body, rather than utilizing HTTP response status codes. HTTP authorization only respects responses with successful HTTP code (2XX) and takes the resolution from the response body (from result) field.

Details

Success response status code:

200 or 204

Other status codes or request failure will be treated as ignore.

Success response body (JSON):

Name	Type	Required	Description
result	Enum	true	`allow

{
  "result": "deny"
}

Example

EMQX 4.4

auth.http.acl_req.url = http://127.0.0.1:80/mqtt/acl
auth.http.acl_req.method = post
auth.http.acl_req.headers.content_type = application/x-www-form-urlencoded

auth.http.acl_req.params = clientid=%c,username=%u,password=%P

auth.http.timeout = 5s

auth.http.connect_timeout = 5s
auth.http.pool_size = 32

auth.http.enable_pipelining = 100

auth.http.ssl = on
auth.http.ssl.cacertfile = path/to/your/cafile.pem
auth.http.ssl.certfile = path/to/your/certfile
auth.http.ssl.keyfile = path/to/your/keyfile
auth.http.ssl.verify = true
auth.http.ssl.server_name_indication = myhttp

EMQX 5.1

{
    type = http

    method = post
    url = "http://127.0.0.1:80/mqtt/acl"
    body {
        username = "${username}"
        clientid = "${clientid}"
        password = "${password}"
    }
    headers {
        "Content-Type" = "application/x-www-form-urlencoded"
    }
    request_timeout = "5s"
    connect_timeout = "5s"
    pool_size = 32
    
    enable_pipelining = 100
    
    ssl {
      enable = true
      verify = verify_peer
    
      keyfile = path/to/your/keyfile
      certfile = path/to/your/certfile
      cacertfile = path/to/your/cafile.pem
      
      server_name_indication = myhttp
    } 
}

Redis

  type = redis

auto_reconnect may be used to reconnect to Redis automatically on failure.

• type is changed to redis_type.
  • For type single, server is changed to servers.
  • For type sentinel, server is changed to servers.
  • For type cluster, database option is no longer available.
• database is changed to database (except for the cluster type; this option is not available for clusters anymore).
• pool is changed to pool_size.
• password is changed to password.
• query_timeout is no longer used.
• ssl.* options are changed to common SSL options. Refer to TLS for External Resource Access.
• auth_cmd is changed to cmd. ${var}-style placeholders should be used in the command.
• Redis data source still only supports white list mode, which requires setting acl_nomatch = deny;
• The access field name changes to action, and the data changes from numbers to action strings.

If you want to continue using the data from in 4.x, please make necessary migrations manually.

The correspondence between 4.x and 5.x data

4.x	5.x	action
1	subscribe	subscribe
2	publish	publish
3	all	subscribe & publish

Data example in 5.x

HSET mqtt_acl:emqx_u t/# subscribe
HSET mqtt_acl:emqx_u # all
HSET mqtt_acl:emqx_u a/1 publish

Example

EMQX 4.4

auth.redis.type = single
auth.redis.server = 127.0.0.1:6379
auth.redis.pool = 8
auth.redis.database = 0
auth.redis.password = pass
assword salt
auth.redis.acl_cmd = HGETALL mqtt_user:%u

auth.redis.password_hash = salt,sha256

auth.redis.ssl = on
auth.redis.ssl.cacertfile = path/to/your/cafile.pem
auth.redis.ssl.certfile = path/to/your/certfile
auth.redis.ssl.keyfile = path/to/your/keyfile
auth.redis.ssl.verify = true
auth.redis.ssl.server_name_indication = myredis

EMQX 5.1

{
  type = redis
  enable = true

  redis_type = single
  server = "127.0.0.1:6379"

  cmd = "HMGET mqtt_user:${username}"
  database = 0
  password = "pass"
  auto_reconnect = true
  ssl {
    enable = true
    verify = verify_peer
   
    keyfile = path/to/your/keyfile
    certfile = path/to/your/certfile
    cacertfile = path/to/your/cafile.pem
    
    server_name_indication = myredis
  }
}

MySQL

  type = mysql

• The ipaddr/username/clientid field is no longer required in the query result.

• The access field name is changed to action, and its data type is changed from integer to character or character enumeration.

• The allow field name is changed to permission, and its data type is changed from integer to character or character enumeration.

  The correspondence between 4.x integer values and 5.x character/enumeration values

  Access/action field mapping

  4.x (int)	5.x (varchar/enum)	action
  1	subscribe	subscribe
  2	publish	publish
  3	all	subscribe & publish

  Allow/permission field mapping

  4.x (int)	5.x (varchar/enum)	permission
  0	deny	deny
  1	allow	allow

• server, username, password, database, query_timeout are retained.

• pool is changed to pool_size.

• ssl.* options are changed to common SSL options. Refer to TLS for External Resource Access.

• acl_query is changed to query. ${var}-style placeholders should be used.

You can use auto_reconnect to reconnect to MySQL automatically on failure.

Storage schema is changed.

In EMQX 4.4, the query should fetch rows with columns [Allow, IpAddr, Username, ClientId, Access, Topic] under any name exactly in this order.

In EMQX 5.1, the query should fetch rows with columns permission, action, topic in any order but under exactly these names. The “who“ part (IpAddr, Username, ClientId) is now suggested to be a part of the query.

Example

EMQX 4.4

auth.mysql.server = 127.0.0.1:3306
auth.mysql.pool = 8
auth.mysql.username = dbuser
auth.mysql.database = mqtt

auth.mysql.query_timeout = 5s

auth.mysql.acl_query = select allow, ipaddr, username, clientid, access, topic from mqtt_acl where username = '%u'

auth.mysql.ssl = on
auth.mysql.ssl.cacertfile = path/to/your/cafile.pem
auth.mysql.ssl.certfile = path/to/your/certfile
auth.mysql.ssl.keyfile = path/to/your/keyfile
auth.mysql.ssl.verify = true
auth.mysql.ssl.server_name_indication = mymysql

EMQX 5.1

{
  type = mysql
  enable = true

  server = "127.0.0.1:3306"
  username = "dbuser"
  database = "mqtt"
  password = "dbpass"
  pool_size = 8


  query = "select allow as permission, access as action, topic from mqtt_acl where username = ${username} and ipaddr = ${peerhost} and clientid = ${clientid}"
  query_timeout = "5s"
  
  auto_reconnect = true
  ssl {
    enable = true
    verify = verify_peer
   
    keyfile = path/to/your/keyfile
    certfile = path/to/your/certfile
    cacertfile = path/to/your/cafile.pem
    
    server_name_indication = mymysql
  }
}

PostgreSQL

type = postgresql

• The ipaddr/username/clientid field is no longer required in the query result.
• The access field name is changed to action, and its data type is changed from integer to character or character enumeration.
• The allow field name is changed to permission, and its data type is changed from integer to character or character enumeration.

The correspondence between 4.x integer values and 5.x character/enumeration values

Access/action field mapping

4.x (int)	5.x (varchar/enum)	action
1	subscribe	subscribe
2	publish	publish
3	all	subscribe & publish

Allow/permission field mapping

4.x (int)	5.x (varchar/enum)	permission
0	deny	deny
1	allow	allow

• server, username, password, database are retained.
• query_timeout is not used anymore.
• encoding is not used anymore.
• pool is changed to pool_size.
• ssl.* options are changed to common SSL options. Refer to TLS for External Resource Access.
• acl_query is changed to query. ${var}-style placeholders should be used.

Storage schema is changed.

In EMQX 4.4, the query should fetch rows with columns [Allow, IpAddr, Username, ClientId, Access, Topic] under any name exactly in this order.

In EMQX 5.1, the query should fetch rows with columns permission, action, topic in any order but under exactly these names. The “who“ part (IpAddr, Username, ClientId) is now suggested to be a part of the query.

Example

EMQX 4.4

auth.pgsql.server = 127.0.0.1:5432
auth.pgsql.pool = 8
auth.pgsql.username = root
auth.pgsql.password = dbpass

auth.pgsql.database = mqtt
auth.pgsql.encoding = utf8

auth.pgsql.acl_query = select allow, ipaddr, username, clientid, access, topic from mqtt_acl where username = '%u'

auth.pgsql.ssl = on
auth.pgsql.ssl.cacertfile = path/to/your/cafile.pem
auth.pgsql.ssl.certfile = path/to/your/certfile
auth.pgsql.ssl.keyfile = path/to/your/keyfile
auth.pgsql.ssl.verify = true
auth.pgsql.ssl.server_name_indication = mypgsql

EMQX 5.1

{
  type = postgresql
  
  enable = true

  server = "127.0.0.1:5432"
  username = "root"
  database = "mqtt"
  password = "dbpass"
  pool_size = 8

  query = "select allow as permission, access as action, topic from mqtt_acl where username = ${username} and ipaddr = ${peerhost} and clientid = ${clientid}"
  
  auto_reconnect = true
  ssl {
    enable = true
    verify = verify_peer
   
    keyfile = path/to/your/keyfile
    certfile = path/to/your/certfile
    cacertfile = path/to/your/cafile.pem
    
    server_name_indication = mypgsql
  }
}

MongoDB

type = mongodb

• type is changed to mongo_type field. Possible values are single, rs, sharded. Unknown value is not available anymore.
• server
  • For rs, sharded to servers
  • For single to server
• srv_record, username, password, auth_source, database, w_mode, topology, collection are retained.
• r_mode is availalable only for rs type.
• pool is changed to pool_size.
• ssl.* is changed to common SSL options. Refer to TLS for External Resource Access.
• auth_query.selector is changed to filter. The filter should not be a string, but the whole selector data structure. ${var}-style placeholders may be used in selector values.
• query_timeout is not used.

Storage schema is changed.

In EMQX 4.4, the resulting documents should contain topics lists by action key, like in Redis or JWT:

{
  "publish": ["t1", "t2"],
  "subscribe": ["t3", "t4"],
  "pubsub": ["t5", "t6"]
}

In EMQX 5.1, MongoDB data source can be used for both allow and deny rules. Previously, only white list mode was supported, and it was required to set acl_nomatch = deny. The documents should contain individual rules with permission, action, topics fields. Note that topics should be an array of topics. For details, see AuthZ-MongoDB.

If you want to continue using the data from in 4.x, please make the necessary migrations manually.

Data example in 5.x

[
  {
      "username": "emqx_u",
      "clientid": "emqx_c",
      "ipaddress": "127.0.0.1",
      "permission": "allow",
      "action": "all",
      "topics": ["#"]
  }
]

Example

EMQX 4.4

auth.mongo.type = single
auth.mongo.srv_record = false
auth.mongo.server = 127.0.0.1:27017
auth.mongo.pool = 8
auth.mongo.username = user
auth.mongo.password = pass
auth.mongo.auth_source = admin
auth.mongo.database = mqtt
auth.mongo.query_timeout = 5s

auth.mongo.ssl = on
auth.mongo.ssl.cacertfile = path/to/your/cafile.pem
auth.mongo.ssl.certfile = path/to/your/certfile
auth.mongo.ssl.keyfile = path/to/your/keyfile
auth.mongo.ssl.verify = true
auth.mongo.ssl.server_name_indication = mymongo

auth.mongo.w_mode = unsafe

auth.mongo.topology.pool_size = 1
auth.mongo.topology.max_overflow = 0


auth.mongo.acl_query.collection = mqtt_user
auth.mongo.acl_query.selector = username=%u, clientid=%c

EMQX 5.1

{
  type = mongodb
  enable = true

  collection = "mqtt_user"
  filter { username = "${username}", clientid = "${clientid}" }
  
  mongo_type = single
  server = "127.0.0.1:27017"

  database = "mqtt"
  username = "emqx"
  password = "pass"
  
  ssl {
    enable = true
    verify = verify_peer
   
    keyfile = path/to/your/keyfile
    certfile = path/to/your/certfile
    cacertfile = path/to/your/cafile.pem
    
    server_name_indication = mymongo
  }
  
  topology {
    pool_size = 1
    max_overflow = 0
  }
}