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-- 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 reconf = config['regexp']
local rspamd_regexp = require "rspamd_regexp"
local rspamd_logger = require "rspamd_logger"
-- Messages that have only HTML part
reconf['MIME_HTML_ONLY'] = 'has_only_html_part()'
local function check_html_image(task, min, max)
local tp = task:get_text_parts()
for _,p in ipairs(tp) do
if p:is_html() then
local hc = p:get_html()
local len = p:get_length()
if len >= min and len < max then
local images = hc:get_images()
if images then
for _,i in ipairs(images) do
if i['embedded'] then
return true
end
end
end
end
end
end
end
rspamd_config.HTML_SHORT_LINK_IMG_1 = {
callback = function(task)
return check_html_image(task, 0, 1024)
end,
score = 3.0,
group = 'html',
description = 'Short html part (0..1K) with a link to an image'
}
rspamd_config.HTML_SHORT_LINK_IMG_2 = {
callback = function(task)
return check_html_image(task, 1024, 1536)
end,
score = 1.0,
group = 'html',
description = 'Short html part (1K..1.5K) with a link to an image'
}
rspamd_config.HTML_SHORT_LINK_IMG_3 = {
callback = function(task)
return check_html_image(task, 1536, 2048)
end,
score = 0.5,
group = 'html',
description = 'Short html part (1.5K..2K) with a link to an image'
}
rspamd_config.R_EMPTY_IMAGE = {
callback = function(task)
local tp = task:get_text_parts() -- get text parts in a message
for _,p in ipairs(tp) do -- iterate over text parts array using `ipairs`
if p:is_html() then -- if the current part is html part
local hc = p:get_html() -- we get HTML context
local len = p:get_length() -- and part's length
if len < 50 then -- if we have a part that has less than 50 bytes of text
local images = hc:get_images() -- then we check for HTML images
if images then -- if there are images
for _,i in ipairs(images) do -- then iterate over images in the part
if i['height'] + i['width'] >= 400 then -- if we have a large image
return true -- add symbol
end
end
end
end
end
end
end,
score = 2.0,
group = 'html',
description = 'Message contains empty parts and image'
}
rspamd_config.R_SUSPICIOUS_IMAGES = {
callback = function(task)
local tp = task:get_text_parts() -- get text parts in a message
for _, p in ipairs(tp) do
local h = p:get_html()
if h then
local l = p:get_words_count()
local img = h:get_images()
local pic_words = 0
if img then
for _, i in ipairs(img) do
if i['embedded'] then
local dim = i['width'] + i['height']
-- do not trigger on small and large images
if dim > 100 and dim < 3000 then
-- We assume that a single picture 100x200 contains approx 3 words of text
pic_words = pic_words + dim / 100
end
end
end
end
if l + pic_words > 0 then
local rel = pic_words / (l + pic_words)
if rel > 0.5 then
return true, (rel - 0.5) * 2
end
end
end
end
return false
end,
score = 5.0,
group = 'html',
description = 'Message contains many suspicious messages'
}
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