spacewander commented on a change in pull request #5727: URL: https://github.com/apache/apisix/pull/5727#discussion_r776543710
########## File path: apisix/plugins/csrf.lua ########## @@ -0,0 +1,170 @@ +-- +-- Licensed to the Apache Software Foundation (ASF) under one or more +-- contributor license agreements. See the NOTICE file distributed with +-- this work for additional information regarding copyright ownership. +-- The ASF licenses this file to You under the Apache License, Version 2.0 +-- (the "License"); you may not use this file except in compliance with +-- the License. You may obtain a copy of the License at +-- +-- http://www.apache.org/licenses/LICENSE-2.0 +-- +-- Unless required by applicable law or agreed to in writing, software +-- distributed under the License is distributed on an "AS IS" BASIS, +-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +-- See the License for the specific language governing permissions and +-- limitations under the License. +-- +local core = require("apisix.core") +local resty_sha256 = require("resty.sha256") +local ck = require("resty.cookie") +local ngx = ngx +local plugin_name = "csrf" +local ngx_encode_base64 = ngx.encode_base64 +local ngx_decode_base64 = ngx.decode_base64 +local ngx_time = ngx.time +local cookie_time = ngx.cookie_time +local math = math + +local schema = { + type = "object", + properties = { + key = { + description = "use to generate csrf token", + type = "string", + }, + expires = { + description = "expires time(s) for csrf token", + type = "integer", + default = 7200 + }, + name = { + description = "the csrf token name", + type = "string", + default = "apisix_csrf_token" + } + }, + required = {"key"} +} + +local _M = { + version = 0.1, + priority = 2980, + name = plugin_name, + schema = schema, +} + +function _M.check_schema(conf) + return core.schema.check(schema, conf) +end + + +local function gen_sign(random, expires, key) + local sha256 = resty_sha256:new() + + local sign = { + random = random, + expires = expires, + key = key, + } + + sha256:update(core.json.encode(sign)) + local digest = sha256:final() + + return ngx_encode_base64(digest) +end + + +local function gen_csrf_token(conf) + local random = math.random() + local sign = gen_sign(random, conf.expires, conf.key) + + local token = { + random = random, + expires = conf.expires, + sign = sign, + } + + local cookie = ngx_encode_base64(core.json.encode(token)) + return cookie +end + + +local function check_csrf_token(conf, ctx, token) + local _token = ngx_decode_base64(token) + if _token == nil then + core.log.error("csrf token is null") + return false + end + + local _token_table, err = core.json.decode(_token) + if err then + core.log.error("decode token error: ", err) + return false + end + + local random = _token_table["random"] + if not random then + core.log.error("no random in token") + return false + end + + local expires = _token_table["expires"] + if not expires then + core.log.error("no expires in token") + return false + end + + local sign = gen_sign(random, expires, conf.key) + if _token_table["sign"] ~= sign then + return false + end + + return true +end + + +function _M.access(conf, ctx) + local method = core.request.get_method(ctx) + if method == 'GET' then + return + end + + local token = core.request.header(ctx, conf.name) + if not token then + return 401, {error_msg = "no csrf token in headers"} + end + + local cookie, err = ck:new() + if not cookie then + return nil, err + end + + local field_cookie, err = cookie:get(conf.name) + if not field_cookie then + return 401, {error_msg = "no csrf cookie"} + end + + if err then + core.log.error(err) + return 400, {error_msg = "read csrf cookie failed"} + end + + if token ~= field_cookie then + return 401, {error_msg = "csrf token mismatch"} + end + + local result = check_csrf_token(conf, ctx, token) + if not result then + return 401, {error_msg = "Failed to verify the csrf token signature"} + end +end + + +function _M.header_filter(conf, ctx) + local csrf_token = gen_csrf_token(conf) + local cookie = conf.name .. "=" .. csrf_token .. ";path=/;Expires=" + .. cookie_time(ngx_time() + conf.expires) + core.response.add_header("Set-Cookie", cookie) +end + Review comment: Ditto ########## File path: docs/en/latest/plugins/csrf.md ########## @@ -0,0 +1,127 @@ +--- +title: csrf +--- + +<!-- +# +# Licensed to the Apache Software Foundation (ASF) under one or more +# contributor license agreements. See the NOTICE file distributed with +# this work for additional information regarding copyright ownership. +# The ASF licenses this file to You under the Apache License, Version 2.0 +# (the "License"); you may not use this file except in compliance with +# the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# +--> + +## Summary + +- [**Description**](#description) +- [**Attributes**](#attributes) +- [**How To Enable**](#how-to-enable) +- [**Test Plugin**](#test-plugin) +- [**Disable Plugin**](#disable-plugin) + +## Description + +The `CSRF` plugin based on the `Double Submit Cookie` way, protect your API from CSRF attacks. + +## Attributes + +| Name | Type | Requirement | Default | Valid | Description | +| ---------------- | ------- | ----------- | ------- | ----- | ------------------------------------------------------------ | +| name | string | false | `apisix_csrf_token` | | The name of the token in the generated cookie. | +| expires | number | false | `7200` | | Expiration time(s) of csrf cookie. | +| key | string | true | | | The secret key used to encrypt the cookie. | + +## How To Enable + +1. Create the route and enable the plugin. + +``` +curl -i http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X POST -d ' Review comment: ```suggestion curl -i http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT-d ' ``` ########## File path: apisix/plugins/csrf.lua ########## @@ -0,0 +1,170 @@ +-- +-- Licensed to the Apache Software Foundation (ASF) under one or more +-- contributor license agreements. See the NOTICE file distributed with +-- this work for additional information regarding copyright ownership. +-- The ASF licenses this file to You under the Apache License, Version 2.0 +-- (the "License"); you may not use this file except in compliance with +-- the License. You may obtain a copy of the License at +-- +-- http://www.apache.org/licenses/LICENSE-2.0 +-- +-- Unless required by applicable law or agreed to in writing, software +-- distributed under the License is distributed on an "AS IS" BASIS, +-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +-- See the License for the specific language governing permissions and +-- limitations under the License. +-- +local core = require("apisix.core") +local resty_sha256 = require("resty.sha256") +local ck = require("resty.cookie") +local ngx = ngx +local plugin_name = "csrf" +local ngx_encode_base64 = ngx.encode_base64 +local ngx_decode_base64 = ngx.decode_base64 +local ngx_time = ngx.time +local cookie_time = ngx.cookie_time +local math = math + +local schema = { + type = "object", + properties = { + key = { + description = "use to generate csrf token", + type = "string", + }, + expires = { + description = "expires time(s) for csrf token", + type = "integer", + default = 7200 + }, + name = { + description = "the csrf token name", + type = "string", + default = "apisix_csrf_token" + } + }, + required = {"key"} +} + +local _M = { + version = 0.1, + priority = 2980, + name = plugin_name, + schema = schema, +} + +function _M.check_schema(conf) + return core.schema.check(schema, conf) +end + + +local function gen_sign(random, expires, key) + local sha256 = resty_sha256:new() + + local sign = { + random = random, + expires = expires, + key = key, + } + + sha256:update(core.json.encode(sign)) + local digest = sha256:final() + + return ngx_encode_base64(digest) +end + + +local function gen_csrf_token(conf) + local random = math.random() + local sign = gen_sign(random, conf.expires, conf.key) + + local token = { + random = random, + expires = conf.expires, + sign = sign, + } + + local cookie = ngx_encode_base64(core.json.encode(token)) + return cookie +end + + +local function check_csrf_token(conf, ctx, token) + local _token = ngx_decode_base64(token) + if _token == nil then + core.log.error("csrf token is null") Review comment: The error message is incorrect. Also, better to avoid using `_token` & `token`, it is quite confusing about the meaning of the `_` prefix. ########## File path: apisix/plugins/csrf.lua ########## @@ -0,0 +1,170 @@ +-- +-- Licensed to the Apache Software Foundation (ASF) under one or more +-- contributor license agreements. See the NOTICE file distributed with +-- this work for additional information regarding copyright ownership. +-- The ASF licenses this file to You under the Apache License, Version 2.0 +-- (the "License"); you may not use this file except in compliance with +-- the License. You may obtain a copy of the License at +-- +-- http://www.apache.org/licenses/LICENSE-2.0 +-- +-- Unless required by applicable law or agreed to in writing, software +-- distributed under the License is distributed on an "AS IS" BASIS, +-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +-- See the License for the specific language governing permissions and +-- limitations under the License. +-- +local core = require("apisix.core") +local resty_sha256 = require("resty.sha256") +local ck = require("resty.cookie") +local ngx = ngx +local plugin_name = "csrf" +local ngx_encode_base64 = ngx.encode_base64 +local ngx_decode_base64 = ngx.decode_base64 +local ngx_time = ngx.time +local cookie_time = ngx.cookie_time +local math = math + +local schema = { Review comment: Please use two blank lines to separate each section (localized functions, define module-level variables, define functions, return _M) ########## File path: apisix/plugins/csrf.lua ########## @@ -0,0 +1,170 @@ +-- +-- Licensed to the Apache Software Foundation (ASF) under one or more +-- contributor license agreements. See the NOTICE file distributed with +-- this work for additional information regarding copyright ownership. +-- The ASF licenses this file to You under the Apache License, Version 2.0 +-- (the "License"); you may not use this file except in compliance with +-- the License. You may obtain a copy of the License at +-- +-- http://www.apache.org/licenses/LICENSE-2.0 +-- +-- Unless required by applicable law or agreed to in writing, software +-- distributed under the License is distributed on an "AS IS" BASIS, +-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +-- See the License for the specific language governing permissions and +-- limitations under the License. +-- +local core = require("apisix.core") +local resty_sha256 = require("resty.sha256") +local ck = require("resty.cookie") +local ngx = ngx +local plugin_name = "csrf" +local ngx_encode_base64 = ngx.encode_base64 +local ngx_decode_base64 = ngx.decode_base64 +local ngx_time = ngx.time +local cookie_time = ngx.cookie_time +local math = math + +local schema = { + type = "object", + properties = { + key = { + description = "use to generate csrf token", + type = "string", + }, + expires = { + description = "expires time(s) for csrf token", + type = "integer", + default = 7200 + }, + name = { + description = "the csrf token name", + type = "string", + default = "apisix_csrf_token" + } + }, + required = {"key"} +} + +local _M = { + version = 0.1, + priority = 2980, + name = plugin_name, + schema = schema, +} + +function _M.check_schema(conf) + return core.schema.check(schema, conf) +end + + +local function gen_sign(random, expires, key) + local sha256 = resty_sha256:new() + + local sign = { + random = random, + expires = expires, + key = key, + } + + sha256:update(core.json.encode(sign)) + local digest = sha256:final() + + return ngx_encode_base64(digest) +end + + +local function gen_csrf_token(conf) + local random = math.random() + local sign = gen_sign(random, conf.expires, conf.key) + + local token = { + random = random, + expires = conf.expires, + sign = sign, + } + + local cookie = ngx_encode_base64(core.json.encode(token)) + return cookie +end + + +local function check_csrf_token(conf, ctx, token) + local _token = ngx_decode_base64(token) + if _token == nil then + core.log.error("csrf token is null") + return false + end + + local _token_table, err = core.json.decode(_token) + if err then + core.log.error("decode token error: ", err) + return false + end + + local random = _token_table["random"] + if not random then + core.log.error("no random in token") + return false + end + + local expires = _token_table["expires"] + if not expires then + core.log.error("no expires in token") + return false + end + + local sign = gen_sign(random, expires, conf.key) + if _token_table["sign"] ~= sign then + return false + end + + return true +end + + +function _M.access(conf, ctx) + local method = core.request.get_method(ctx) + if method == 'GET' then + return + end + + local token = core.request.header(ctx, conf.name) + if not token then + return 401, {error_msg = "no csrf token in headers"} + end + + local cookie, err = ck:new() + if not cookie then + return nil, err + end + + local field_cookie, err = cookie:get(conf.name) + if not field_cookie then + return 401, {error_msg = "no csrf cookie"} + end + + if err then + core.log.error(err) + return 400, {error_msg = "read csrf cookie failed"} + end + + if token ~= field_cookie then + return 401, {error_msg = "csrf token mismatch"} + end + + local result = check_csrf_token(conf, ctx, token) + if not result then + return 401, {error_msg = "Failed to verify the csrf token signature"} + end +end + + +function _M.header_filter(conf, ctx) + local csrf_token = gen_csrf_token(conf) + local cookie = conf.name .. "=" .. csrf_token .. ";path=/;Expires=" Review comment: Should we set the SameSite field for the cookie? ########## File path: apisix/plugins/csrf.lua ########## @@ -0,0 +1,170 @@ +-- +-- Licensed to the Apache Software Foundation (ASF) under one or more +-- contributor license agreements. See the NOTICE file distributed with +-- this work for additional information regarding copyright ownership. +-- The ASF licenses this file to You under the Apache License, Version 2.0 +-- (the "License"); you may not use this file except in compliance with +-- the License. You may obtain a copy of the License at +-- +-- http://www.apache.org/licenses/LICENSE-2.0 +-- +-- Unless required by applicable law or agreed to in writing, software +-- distributed under the License is distributed on an "AS IS" BASIS, +-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +-- See the License for the specific language governing permissions and +-- limitations under the License. +-- +local core = require("apisix.core") +local resty_sha256 = require("resty.sha256") +local ck = require("resty.cookie") +local ngx = ngx +local plugin_name = "csrf" +local ngx_encode_base64 = ngx.encode_base64 +local ngx_decode_base64 = ngx.decode_base64 +local ngx_time = ngx.time +local cookie_time = ngx.cookie_time +local math = math + +local schema = { + type = "object", + properties = { + key = { + description = "use to generate csrf token", + type = "string", + }, + expires = { + description = "expires time(s) for csrf token", + type = "integer", + default = 7200 + }, + name = { + description = "the csrf token name", + type = "string", + default = "apisix_csrf_token" + } + }, + required = {"key"} +} + +local _M = { + version = 0.1, + priority = 2980, + name = plugin_name, + schema = schema, +} + +function _M.check_schema(conf) + return core.schema.check(schema, conf) +end + + +local function gen_sign(random, expires, key) + local sha256 = resty_sha256:new() + + local sign = { + random = random, + expires = expires, + key = key, + } + + sha256:update(core.json.encode(sign)) + local digest = sha256:final() + + return ngx_encode_base64(digest) +end + + +local function gen_csrf_token(conf) + local random = math.random() + local sign = gen_sign(random, conf.expires, conf.key) + + local token = { + random = random, + expires = conf.expires, + sign = sign, + } + + local cookie = ngx_encode_base64(core.json.encode(token)) + return cookie +end + + +local function check_csrf_token(conf, ctx, token) + local _token = ngx_decode_base64(token) + if _token == nil then + core.log.error("csrf token is null") + return false + end + + local _token_table, err = core.json.decode(_token) + if err then + core.log.error("decode token error: ", err) + return false + end + + local random = _token_table["random"] + if not random then + core.log.error("no random in token") + return false + end + + local expires = _token_table["expires"] + if not expires then + core.log.error("no expires in token") + return false + end + + local sign = gen_sign(random, expires, conf.key) + if _token_table["sign"] ~= sign then + return false + end + + return true +end + + +function _M.access(conf, ctx) + local method = core.request.get_method(ctx) + if method == 'GET' then + return + end + + local token = core.request.header(ctx, conf.name) + if not token then + return 401, {error_msg = "no csrf token in headers"} + end + + local cookie, err = ck:new() + if not cookie then + return nil, err + end + + local field_cookie, err = cookie:get(conf.name) + if not field_cookie then + return 401, {error_msg = "no csrf cookie"} + end + + if err then + core.log.error(err) + return 400, {error_msg = "read csrf cookie failed"} + end + + if token ~= field_cookie then + return 401, {error_msg = "csrf token mismatch"} + end + + local result = check_csrf_token(conf, ctx, token) + if not result then + return 401, {error_msg = "Failed to verify the csrf token signature"} + end +end + + +function _M.header_filter(conf, ctx) + local csrf_token = gen_csrf_token(conf) Review comment: Better to emphasize in the doc that a new cookie is generated for each request -- This is an automated message from the Apache Git Service. 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