mirror of
https://github.com/rspamd/rspamd.git
synced 2024-08-16 02:13:24 +02:00
340 lines
9.9 KiB
Lua
340 lines
9.9 KiB
Lua
-- Licensed to the Apache Software Foundation (ASF) under one or more
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-- contributor license agreements. See the NOTICE file distributed with
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-- this work for additional information regarding copyright ownership.
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-- The ASF licenses this file to you under the Apache License, Version 2.0
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-- (the "License"); you may not use this file except in compliance with
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-- the License. You may obtain a copy of the License at:
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--
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-- http://www.apache.org/licenses/LICENSE-2.0
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--
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-- Unless required by applicable law or agreed to in writing, software
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-- distributed under the License is distributed on an "AS IS" BASIS,
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-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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-- See the License for the specific language governing permissions and
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-- limitations under the License.
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local reconf = config['regexp']
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-- Messages that have only HTML part
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reconf['MIME_HTML_ONLY'] = {
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re = 'has_only_html_part()',
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score = 0.2,
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description = 'Messages that have only HTML part',
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group = 'headers'
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}
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local function check_html_image(task, min, max)
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local tp = task:get_text_parts()
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for _,p in ipairs(tp) do
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if p:is_html() then
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local hc = p:get_html()
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local len = p:get_length()
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if hc and len >= min and len < max then
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local images = hc:get_images()
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if images then
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for _,i in ipairs(images) do
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local tag = i['tag']
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if tag then
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local parent = tag:get_parent()
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if parent then
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if parent:get_type() == 'a' then
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-- do not trigger on small and unknown size images
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if i['height'] + i['width'] >= 210 or not i['embedded'] then
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return true
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end
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end
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end
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end
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end
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end
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end
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end
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end
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end
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rspamd_config.HTML_SHORT_LINK_IMG_1 = {
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callback = function(task)
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return check_html_image(task, 0, 1024)
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end,
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score = 2.0,
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group = 'html',
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description = 'Short html part (0..1K) with a link to an image'
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}
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rspamd_config.HTML_SHORT_LINK_IMG_2 = {
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callback = function(task)
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return check_html_image(task, 1024, 1536)
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end,
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score = 1.0,
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group = 'html',
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description = 'Short html part (1K..1.5K) with a link to an image'
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}
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rspamd_config.HTML_SHORT_LINK_IMG_3 = {
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callback = function(task)
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return check_html_image(task, 1536, 2048)
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end,
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score = 0.5,
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group = 'html',
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description = 'Short html part (1.5K..2K) with a link to an image'
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}
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rspamd_config.R_EMPTY_IMAGE = {
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callback = function(task)
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local tp = task:get_text_parts() -- get text parts in a message
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for _,p in ipairs(tp) do -- iterate over text parts array using `ipairs`
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if p:is_html() then -- if the current part is html part
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local hc = p:get_html() -- we get HTML context
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local len = p:get_length() -- and part's length
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if hc and len < 50 then -- if we have a part that has less than 50 bytes of text
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local images = hc:get_images() -- then we check for HTML images
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if images then -- if there are images
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for _,i in ipairs(images) do -- then iterate over images in the part
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if i['height'] + i['width'] >= 400 then -- if we have a large image
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local tag = i['tag']
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if tag then
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local parent = tag:get_parent()
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if parent then
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if parent:get_type() ~= 'a' then
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return true
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end
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end
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end
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end
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end
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end
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end
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end
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end
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end,
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score = 2.0,
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group = 'html',
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description = 'Message contains empty parts and image'
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}
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rspamd_config.R_SUSPICIOUS_IMAGES = {
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callback = function(task)
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local tp = task:get_text_parts() -- get text parts in a message
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for _, p in ipairs(tp) do
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local h = p:get_html()
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if h then
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local l = p:get_words_count()
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local img = h:get_images()
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local pic_words = 0
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if img then
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for _, i in ipairs(img) do
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local dim = i['width'] + i['height']
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local tag = i['tag']
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if tag then
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local parent = tag:get_parent()
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if parent then
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if parent:get_type() == 'a' then
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-- do not trigger on small and large images
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if dim > 100 and dim < 3000 then
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-- We assume that a single picture 100x200 contains approx 3 words of text
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pic_words = pic_words + dim / 100
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end
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end
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end
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end
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end
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end
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if l + pic_words > 0 then
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local rel = pic_words / (l + pic_words)
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if rel > 0.5 then
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return true, (rel - 0.5) * 2
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end
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end
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end
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end
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return false
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end,
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score = 5.0,
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group = 'html',
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description = 'Message contains many suspicious messages'
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}
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rspamd_config.R_WHITE_ON_WHITE = {
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callback = function(task)
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local tp = task:get_text_parts() -- get text parts in a message
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local ret = false
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local diff = 0.0
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local transp_rate = 0
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local arg
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for _,p in ipairs(tp) do -- iterate over text parts array using `ipairs`
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if p:is_html() and p:get_html() then -- if the current part is html part
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local normal_len = p:get_length()
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local transp_len = 0
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local hc = p:get_html() -- we get HTML context
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hc:foreach_tag({'font', 'span', 'div', 'p'}, function(tag)
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local bl = tag:get_extra()
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if bl then
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if bl['bgcolor'] and bl['color'] and bl['visible'] then
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local color = bl['color']
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local bgcolor = bl['bgcolor']
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-- Should use visual approach here some day
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local diff_r = math.abs(color[1] - bgcolor[1]) / 255.0
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local diff_g = math.abs(color[2] - bgcolor[2]) / 255.0
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local diff_b = math.abs(color[3] - bgcolor[3]) / 255.0
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diff = (diff_r + diff_g + diff_b) / 3.0
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if diff < 0.1 then
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ret = true
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transp_len = (tag:get_content_length()) *
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(0.1 - diff) * 5.0
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normal_len = normal_len - tag:get_content_length()
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local tr = transp_len / (normal_len + transp_len)
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if tr > transp_rate then
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transp_rate = tr
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arg = string.format('%s color #%x%x%x bgcolor #%x%x%x',
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tostring(tag:get_type()),
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color[1], color[2], color[3],
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bgcolor[1], bgcolor[2], bgcolor[3])
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end
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end
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end
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end
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return false -- Continue search
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end)
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end
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end
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if ret then
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if transp_rate > 0.1 then
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if transp_rate > 0.5 or transp_rate ~= transp_rate then
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transp_rate = 0.5
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end
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return true,(transp_rate * 2.0),arg
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end
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end
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return false
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end,
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score = 4.0,
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group = 'html',
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one_shot = true,
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description = 'Message contains low contrast text'
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}
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rspamd_config.EXT_CSS = {
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callback = function(task)
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local regexp_lib = require "rspamd_regexp"
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local re = regexp_lib.create_cached('/^.*\\.css(?:[?#].*)?$/i')
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local tp = task:get_text_parts() -- get text parts in a message
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local ret = false
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for _,p in ipairs(tp) do -- iterate over text parts array using `ipairs`
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if p:is_html() and p:get_html() then -- if the current part is html part
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local hc = p:get_html() -- we get HTML context
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hc:foreach_tag({'link'}, function(tag)
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local bl = tag:get_extra()
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if bl then
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local s = tostring(bl)
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if s and re:match(s) then
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ret = true
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end
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end
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return ret -- Continue search
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end)
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end
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end
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return ret
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end,
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score = 1.0,
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group = 'html',
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description = 'Message contains external CSS reference'
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}
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rspamd_config.HTTP_TO_HTTPS = {
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callback = function(task)
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local tp = task:get_text_parts()
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if (not tp) then return false end
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for _,p in ipairs(tp) do
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if p:is_html() then
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local hc = p:get_html()
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if (not hc) then return false end
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local found = false
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hc:foreach_tag('a', function (tag, length)
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-- Skip this loop if we already have a match
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if (found) then return true end
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local c = tag:get_content()
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if (c) then
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c = tostring(c):lower()
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if (not c:match('^http')) then return false end
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local u = tag:get_extra()
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if (not u) then return false end
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u = tostring(u):lower()
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if (not u:match('^http')) then return false end
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if ((c:match('^http:') and u:match('^https:')) or
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(c:match('^https:') and u:match('^http:')))
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then
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found = true
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return true
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end
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end
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return false
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end)
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if (found) then return true end
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return false
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end
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end
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return false
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end,
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description = 'Anchor text contains different scheme to target URL',
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score = 2.0,
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group = 'html'
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}
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rspamd_config.HTTP_TO_IP = {
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callback = function(task)
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local tp = task:get_text_parts()
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if (not tp) then return false end
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for _,p in ipairs(tp) do
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if p:is_html() then
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local hc = p:get_html()
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if (not hc) then return false end
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local found = false
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hc:foreach_tag('a', function (tag, length)
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if (found) then return true end
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local u = tag:get_extra()
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if (u) then
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u = tostring(u):lower()
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if (u:match('^https?://%d+%.%d+%.%d+%.%d+')) then
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found = true
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end
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end
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return false
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end)
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if found then return true end
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return false
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end
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end
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end,
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description = 'Anchor points to an IP address',
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score = 1.0,
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group = 'html'
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}
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