├── kong-plugin-mtls-auth-1.0.0-0.rockspec ├── kong └── plugins │ └── mtls-auth │ ├── schema.lua │ └── handler.lua ├── README.md └── LICENSE /kong-plugin-mtls-auth-1.0.0-0.rockspec: -------------------------------------------------------------------------------- 1 | local plugin_name = "mtls-auth" 2 | local package_name = "kong-plugin-"..plugin_name 3 | local package_version = "1.0.0" 4 | local rockspec_revision = "0" 5 | 6 | package = package_name 7 | version = package_version .. "-" .. rockspec_revision 8 | supported_platforms = { "linux", "macosx" } 9 | 10 | source = { 11 | url = "git://github.com/callistaenterprise/kong-plugin-mtls-auth", 12 | tag = "v1.0.0", 13 | dir = "kong-plugin-mtls-auth" 14 | } 15 | 16 | description = { 17 | summary = "Kong Gateway plugin used to authenticate clients using mTLS", 18 | detailed = [[ 19 | kong-plugin-mtls-auth is a Kong Gateway plugin for authenticating clients using mTLS. 20 | It is similar (but simpler) than the mTLS plugin provided in Kong Enterprise edition. 21 | 22 | Information extracted from the mTLS client certificate can be made available using headers for 23 | the upstream service, or used by other plugins (such as the kong-plugin-mtls-acl plugin) 24 | to further limit access. 25 | ]], 26 | homepage = "https://github.com/callistaenterprise/kong-plugin-mtls-auth", 27 | license = "Apache 2.0", 28 | } 29 | 30 | dependencies = { 31 | } 32 | 33 | build = { 34 | type = "builtin", 35 | modules = { 36 | ["kong.plugins."..plugin_name..".handler"] = "kong/plugins/"..plugin_name.."/handler.lua", 37 | ["kong.plugins."..plugin_name..".schema"] = "kong/plugins/"..plugin_name.."/schema.lua", 38 | } 39 | } 40 | -------------------------------------------------------------------------------- /kong/plugins/mtls-auth/schema.lua: -------------------------------------------------------------------------------- 1 | local typedefs = require "kong.db.schema.typedefs" 2 | 3 | return { 4 | name = "mtls-auth", 5 | fields = { 6 | { consumer = typedefs.no_consumer }, 7 | { protocols = typedefs.protocols_http }, 8 | { 9 | config = { 10 | type = "record", 11 | fields = { 12 | { 13 | error_response_code = { 14 | type = "number", 15 | required = false, 16 | default = 401, 17 | }, 18 | }, 19 | { 20 | upstream_cert_header = { 21 | type = "string", 22 | required = false, 23 | }, 24 | }, 25 | { 26 | upstream_cert_fingerprint_header = { 27 | type = "string", 28 | required = false, 29 | }, 30 | }, 31 | { 32 | upstream_cert_serial_header = { 33 | type = "string", 34 | required = false, 35 | }, 36 | }, 37 | { 38 | upstream_cert_i_dn_header = { 39 | type = "string", 40 | required = false, 41 | }, 42 | }, 43 | { 44 | upstream_cert_s_dn_header = { 45 | type = "string", 46 | required = false, 47 | }, 48 | }, 49 | { 50 | upstream_cert_cn_header = { 51 | type = "string", 52 | required = false, 53 | }, 54 | }, 55 | { 56 | upstream_cert_org_header = { 57 | type = "string", 58 | required = false, 59 | }, 60 | }, 61 | }, 62 | }, 63 | }, 64 | }, 65 | entity_checks = {}, 66 | } 67 | -------------------------------------------------------------------------------- /kong/plugins/mtls-auth/handler.lua: -------------------------------------------------------------------------------- 1 | local BasePlugin = require("kong.plugins.base_plugin") 2 | local set_header = kong.service.request.set_header 3 | 4 | -- utils 5 | local function is_empty(s) 6 | return s == nil or s == '' 7 | end 8 | 9 | -- extract 'relative distinguished name' (which is a KEY=VALUE pair) from a 10 | -- distinguished name string, as given by start and end position 11 | local function extract_and_add_rdn (t, dn, startPos, endPos) 12 | local delimiterPos, _ = string.find(dn, "=", startPos) 13 | if (delimiterPos) 14 | then 15 | local k = string.sub(dn, startPos, delimiterPos-1) 16 | local v = string.sub(dn, delimiterPos+1, endPos) 17 | t[k] = v 18 | end 19 | end 20 | 21 | -- parse a distinguished name string in rfc2253 format into map of 'relative distinguished names' 22 | -- (i.e. KEY=VALUE pairs), allowing VALUEs to contain '\'-escaped comma characters 23 | local function parse_dn (dn) 24 | local t={} 25 | local nextRdn = 1 26 | while(nextRdn <= #dn) 27 | do 28 | local endOfRdnPos, _ = string.find(dn, "[^\\],", nextRdn) 29 | if (endOfRdnPos == nil) then 30 | endOfRdnPos = #dn 31 | end 32 | extract_and_add_rdn (t, dn, nextRdn, endOfRdnPos) 33 | nextRdn = endOfRdnPos+2 34 | end 35 | return t 36 | end 37 | 38 | local MtlsAuth = BasePlugin:extend() 39 | 40 | MtlsAuth.VERSION = "1.0.0" 41 | MtlsAuth.PRIORITY = 975 42 | 43 | function MtlsAuth:new() 44 | MtlsAuth.super.new(self, "mtls-auth") 45 | end 46 | 47 | function MtlsAuth:access(config) 48 | MtlsAuth.super.access(self) 49 | 50 | if ngx.var.ssl_client_verify ~= "SUCCESS" then 51 | kong.response.exit(config.error_response_code, [[{"error":"invalid_request", "error_description": "mTLS client not provided or invalid"}]], { 52 | ["Content-Type"] = "application/json" 53 | }) 54 | end 55 | 56 | local cert_dn = parse_dn(ngx.var.ssl_client_s_dn) 57 | 58 | if not is_empty(config.upstream_cert_header) then 59 | set_header(config.upstream_cert_header, ngx.var.ssl_client_escaped_cert) 60 | end 61 | 62 | if not is_empty(config.upstream_cert_fingerprint_header) then 63 | set_header(config.upstream_cert_fingerprint_header, ngx.var.ssl_client_fingerprint) 64 | end 65 | 66 | if not is_empty(config.upstream_cert_serial_header) then 67 | set_header(config.upstream_cert_serial_header, ngx.var.ssl_client_serial) 68 | end 69 | 70 | if not is_empty(config.upstream_cert_i_dn_header) then 71 | set_header(config.upstream_cert_i_dn_header, ngx.var.ssl_client_i_dn) 72 | end 73 | 74 | if not is_empty(config.upstream_cert_s_dn_header) then 75 | set_header(config.upstream_cert_s_dn_header, ngx.var.ssl_client_s_dn) 76 | end 77 | 78 | if not is_empty(config.upstream_cert_cn_header) then 79 | set_header(config.upstream_cert_cn_header, cert_dn["CN"]) 80 | end 81 | 82 | if not is_empty(config.upstream_cert_org_header) then 83 | set_header(config.upstream_cert_org_header, cert_dn["O"]) 84 | end 85 | 86 | end 87 | 88 | return MtlsAuth 89 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # kong-plugin-mtls-auth 2 | 3 | **kong-plugin-mtls-auth** is an Open Source plugin for [Kong](https://github.com/Mashape/kong) which authenticates 4 | clients using mTLS. It is similar (but simpler) than the [mTLS](https://docs.konghq.com/hub/kong-inc/mtls-auth/) plugin provided in Kong Enterprise edition. 5 | 6 | Information extracted from the mTLS client certificate can be made available using headers for 7 | the upstream service, or used by other plugins (such as the [kong-plugin-mtls-acl](https://github.com/callistaenterprise/kong-plugin-mtls-acl) plugins) 8 | to further limit access. 9 | 10 | The implementation of this plugin was inspired by the 11 | [mtls-validate](https://github.com/emersonqueiroz/kong-plugin-mtls-validate) plugin. 12 | 13 | ## Installation 14 | 15 | If you're using `luarocks` execute the following: 16 | 17 | luarocks install kong-plugin-mtls-auth 18 | 19 | You also need to set the `KONG_PLUGINS` environment variable 20 | 21 | export KONG_PLUGINS=mtls-auth 22 | 23 | ## Configuration 24 | 25 | Configure nginx to use verify client certificate in `kong.conf`: 26 | 27 | nginx_proxy_ssl_client_certificate = /path/to/rootCA.crt 28 | nginx_proxy_ssl_verify_client = on 29 | 30 | To enable the plugin only for one service: 31 | 32 | curl -X POST http://localhost:8001/services/{ID}/plugins \ 33 | --data "name=mtls-auth" \ 34 | --data "config.upstream_cert_cn_header=X-Client-Cert-San" 35 | 36 | To enable the plugin using declarative config in `kong.yml`: 37 | 38 | plugins: 39 | - name: mtls-auth 40 | config: 41 | upstream_cert_cn_header: "X-Client-Cert-San" 42 | 43 | 44 | ### Parameters 45 | 46 | | Parameter | Default | Required | Description | 47 | |------------------------------------|---------|----------|----------------------------------------------------------------------------------------------------------------------------| 48 | | `error_response_code` | 401 | false | Response code to return if client certificate validation fails | 49 | | `upstream_cert_header` | | false | HTTP header name in which the client certificate in PEM format (urlencoded) will be made available to the upstream service | 50 | | `upstream_cert_fingerprint_header` | | false | HTTP header name in which the client certificate fingerprint will be made available to the upstream service | 51 | | `upstream_cert_serial_header` | | false | HTTP header name in which the client certificate serial number will be made available to the upstream service | 52 | | `upstream_cert_i_dn_header` | | false | HTTP header name in which the client certificate issuer DN will be made available to the upstream service | 53 | | `upstream_cert_s_dn_header` | | false | HTTP header name in which the client certificate subject DN will be made available to the upstream service | 54 | | `upstream_cert_cn_header` | | false | HTTP header name in which the client certificate Common Name will be made available to the upstream service | 55 | | `upstream_cert_org_header` | | false | HTTP header name in which the client certificate Organization will be made available to the upstream service | 56 | 57 | 58 | ## License 59 | 60 | Copyright 2023 Björn Beskow, Callista Enterprise AB 61 | 62 | Licensed under the Apache License, Version 2.0 (the "License"); 63 | you may not use this file except in compliance with the License. 64 | You may obtain a copy of the License at 65 | 66 | http://www.apache.org/licenses/LICENSE-2.0 67 | 68 | Unless required by applicable law or agreed to in writing, software 69 | distributed under the License is distributed on an "AS IS" BASIS, 70 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 71 | See the License for the specific language governing permissions and 72 | limitations under the License. -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. 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