discourse/lib/upload_security.rb

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FEATURE: Secure media allowing duplicated uploads with category-level privacy and post-based access rules (#8664) ### General Changes and Duplication * We now consider a post `with_secure_media?` if it is in a read-restricted category. * When uploading we now set an upload's secure status straight away. * When uploading if `SiteSetting.secure_media` is enabled, we do not check to see if the upload already exists using the `sha1` digest of the upload. The `sha1` column of the upload is filled with a `SecureRandom.hex(20)` value which is the same length as `Upload::SHA1_LENGTH`. The `original_sha1` column is filled with the _real_ sha1 digest of the file. * Whether an upload `should_be_secure?` is now determined by whether the `access_control_post` is `with_secure_media?` (if there is no access control post then we leave the secure status as is). * When serializing the upload, we now cook the URL if the upload is secure. This is so it shows up correctly in the composer preview, because we set secure status on upload. ### Viewing Secure Media * The secure-media-upload URL will take the post that the upload is attached to into account via `Guardian.can_see?` for access permissions * If there is no `access_control_post` then we just deliver the media. This should be a rare occurrance and shouldn't cause issues as the `access_control_post` is set when `link_post_uploads` is called via `CookedPostProcessor` ### Removed We no longer do any of these because we do not reuse uploads by sha1 if secure media is enabled. * We no longer have a way to prevent cross-posting of a secure upload from a private context to a public context. * We no longer have to set `secure: false` for uploads when uploading for a theme component.
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# frozen_string_literal: true
##
# A note on determining whether an upload should be marked as secure:
#
# Some of these flags checked (e.g. all of the for_X flags and the opts[:type])
# are only set when _initially uploading_ via UploadCreator and are not present
# when an upload already exists, these will only be checked when the @creating
# option is present.
FEATURE: Secure media allowing duplicated uploads with category-level privacy and post-based access rules (#8664) ### General Changes and Duplication * We now consider a post `with_secure_media?` if it is in a read-restricted category. * When uploading we now set an upload's secure status straight away. * When uploading if `SiteSetting.secure_media` is enabled, we do not check to see if the upload already exists using the `sha1` digest of the upload. The `sha1` column of the upload is filled with a `SecureRandom.hex(20)` value which is the same length as `Upload::SHA1_LENGTH`. The `original_sha1` column is filled with the _real_ sha1 digest of the file. * Whether an upload `should_be_secure?` is now determined by whether the `access_control_post` is `with_secure_media?` (if there is no access control post then we leave the secure status as is). * When serializing the upload, we now cook the URL if the upload is secure. This is so it shows up correctly in the composer preview, because we set secure status on upload. ### Viewing Secure Media * The secure-media-upload URL will take the post that the upload is attached to into account via `Guardian.can_see?` for access permissions * If there is no `access_control_post` then we just deliver the media. This should be a rare occurrance and shouldn't cause issues as the `access_control_post` is set when `link_post_uploads` is called via `CookedPostProcessor` ### Removed We no longer do any of these because we do not reuse uploads by sha1 if secure media is enabled. * We no longer have a way to prevent cross-posting of a secure upload from a private context to a public context. * We no longer have to set `secure: false` for uploads when uploading for a theme component.
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#
# If the upload already exists the best way to figure out whether it should be
# secure alongside the site settings is the access_control_post_id, because the
# original post the upload is linked to has far more bearing on its security context
# post-upload. If the access_control_post_id does not exist then we just rely
# on the current secure? status, otherwise there would be a lot of additional
# complex queries and joins to perform.
#
# These queries will be performed only if the @creating option is false. So if
# an upload is included in a post, and it's an upload from a different source
# (e.g. a category logo, site setting upload) then we will determine secure
# state _based on the first place the upload was referenced_.
#
# NOTE: When updating this to add more cases where uploads will be marked
# secure, consider uploads:secure_upload_analyse_and_update as well, which
# does not use this class directly but uses an SQL version of its rules for
# efficient updating of many uploads in bulk.
FEATURE: Secure media allowing duplicated uploads with category-level privacy and post-based access rules (#8664) ### General Changes and Duplication * We now consider a post `with_secure_media?` if it is in a read-restricted category. * When uploading we now set an upload's secure status straight away. * When uploading if `SiteSetting.secure_media` is enabled, we do not check to see if the upload already exists using the `sha1` digest of the upload. The `sha1` column of the upload is filled with a `SecureRandom.hex(20)` value which is the same length as `Upload::SHA1_LENGTH`. The `original_sha1` column is filled with the _real_ sha1 digest of the file. * Whether an upload `should_be_secure?` is now determined by whether the `access_control_post` is `with_secure_media?` (if there is no access control post then we leave the secure status as is). * When serializing the upload, we now cook the URL if the upload is secure. This is so it shows up correctly in the composer preview, because we set secure status on upload. ### Viewing Secure Media * The secure-media-upload URL will take the post that the upload is attached to into account via `Guardian.can_see?` for access permissions * If there is no `access_control_post` then we just deliver the media. This should be a rare occurrance and shouldn't cause issues as the `access_control_post` is set when `link_post_uploads` is called via `CookedPostProcessor` ### Removed We no longer do any of these because we do not reuse uploads by sha1 if secure media is enabled. * We no longer have a way to prevent cross-posting of a secure upload from a private context to a public context. * We no longer have to set `secure: false` for uploads when uploading for a theme component.
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class UploadSecurity
@@custom_public_types = []
PUBLIC_TYPES = %w[
avatar
custom_emoji
profile_background
card_background
category_logo
category_logo_dark
category_background
group_flair
badge_image
]
PUBLIC_UPLOAD_REFERENCE_TYPES = %w[
Badge
Category
CustomEmoji
Group
SiteSetting
ThemeField
User
UserAvatar
UserProfile
]
def self.register_custom_public_type(type)
@@custom_public_types << type if !@@custom_public_types.include?(type)
end
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# used in tests
def self.reset_custom_public_types
@@custom_public_types = []
end
FEATURE: Secure media allowing duplicated uploads with category-level privacy and post-based access rules (#8664) ### General Changes and Duplication * We now consider a post `with_secure_media?` if it is in a read-restricted category. * When uploading we now set an upload's secure status straight away. * When uploading if `SiteSetting.secure_media` is enabled, we do not check to see if the upload already exists using the `sha1` digest of the upload. The `sha1` column of the upload is filled with a `SecureRandom.hex(20)` value which is the same length as `Upload::SHA1_LENGTH`. The `original_sha1` column is filled with the _real_ sha1 digest of the file. * Whether an upload `should_be_secure?` is now determined by whether the `access_control_post` is `with_secure_media?` (if there is no access control post then we leave the secure status as is). * When serializing the upload, we now cook the URL if the upload is secure. This is so it shows up correctly in the composer preview, because we set secure status on upload. ### Viewing Secure Media * The secure-media-upload URL will take the post that the upload is attached to into account via `Guardian.can_see?` for access permissions * If there is no `access_control_post` then we just deliver the media. This should be a rare occurrance and shouldn't cause issues as the `access_control_post` is set when `link_post_uploads` is called via `CookedPostProcessor` ### Removed We no longer do any of these because we do not reuse uploads by sha1 if secure media is enabled. * We no longer have a way to prevent cross-posting of a secure upload from a private context to a public context. * We no longer have to set `secure: false` for uploads when uploading for a theme component.
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def initialize(upload, opts = {})
@upload = upload
@opts = opts
@upload_type = @opts[:type]
@creating = @opts[:creating]
FEATURE: Secure media allowing duplicated uploads with category-level privacy and post-based access rules (#8664) ### General Changes and Duplication * We now consider a post `with_secure_media?` if it is in a read-restricted category. * When uploading we now set an upload's secure status straight away. * When uploading if `SiteSetting.secure_media` is enabled, we do not check to see if the upload already exists using the `sha1` digest of the upload. The `sha1` column of the upload is filled with a `SecureRandom.hex(20)` value which is the same length as `Upload::SHA1_LENGTH`. The `original_sha1` column is filled with the _real_ sha1 digest of the file. * Whether an upload `should_be_secure?` is now determined by whether the `access_control_post` is `with_secure_media?` (if there is no access control post then we leave the secure status as is). * When serializing the upload, we now cook the URL if the upload is secure. This is so it shows up correctly in the composer preview, because we set secure status on upload. ### Viewing Secure Media * The secure-media-upload URL will take the post that the upload is attached to into account via `Guardian.can_see?` for access permissions * If there is no `access_control_post` then we just deliver the media. This should be a rare occurrance and shouldn't cause issues as the `access_control_post` is set when `link_post_uploads` is called via `CookedPostProcessor` ### Removed We no longer do any of these because we do not reuse uploads by sha1 if secure media is enabled. * We no longer have a way to prevent cross-posting of a secure upload from a private context to a public context. * We no longer have to set `secure: false` for uploads when uploading for a theme component.
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end
def should_be_secure?
should_be_secure_with_reason.first
FEATURE: Secure media allowing duplicated uploads with category-level privacy and post-based access rules (#8664) ### General Changes and Duplication * We now consider a post `with_secure_media?` if it is in a read-restricted category. * When uploading we now set an upload's secure status straight away. * When uploading if `SiteSetting.secure_media` is enabled, we do not check to see if the upload already exists using the `sha1` digest of the upload. The `sha1` column of the upload is filled with a `SecureRandom.hex(20)` value which is the same length as `Upload::SHA1_LENGTH`. The `original_sha1` column is filled with the _real_ sha1 digest of the file. * Whether an upload `should_be_secure?` is now determined by whether the `access_control_post` is `with_secure_media?` (if there is no access control post then we leave the secure status as is). * When serializing the upload, we now cook the URL if the upload is secure. This is so it shows up correctly in the composer preview, because we set secure status on upload. ### Viewing Secure Media * The secure-media-upload URL will take the post that the upload is attached to into account via `Guardian.can_see?` for access permissions * If there is no `access_control_post` then we just deliver the media. This should be a rare occurrance and shouldn't cause issues as the `access_control_post` is set when `link_post_uploads` is called via `CookedPostProcessor` ### Removed We no longer do any of these because we do not reuse uploads by sha1 if secure media is enabled. * We no longer have a way to prevent cross-posting of a secure upload from a private context to a public context. * We no longer have to set `secure: false` for uploads when uploading for a theme component.
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end
def should_be_secure_with_reason
insecure_context_checks.each { |check, reason| return false, reason if perform_check(check) }
secure_context_checks.each do |check, reason|
return perform_check(check), reason if priority_check?(check)
return true, reason if perform_check(check)
end
[false, "no checks satisfied"]
FEATURE: Secure media allowing duplicated uploads with category-level privacy and post-based access rules (#8664) ### General Changes and Duplication * We now consider a post `with_secure_media?` if it is in a read-restricted category. * When uploading we now set an upload's secure status straight away. * When uploading if `SiteSetting.secure_media` is enabled, we do not check to see if the upload already exists using the `sha1` digest of the upload. The `sha1` column of the upload is filled with a `SecureRandom.hex(20)` value which is the same length as `Upload::SHA1_LENGTH`. The `original_sha1` column is filled with the _real_ sha1 digest of the file. * Whether an upload `should_be_secure?` is now determined by whether the `access_control_post` is `with_secure_media?` (if there is no access control post then we leave the secure status as is). * When serializing the upload, we now cook the URL if the upload is secure. This is so it shows up correctly in the composer preview, because we set secure status on upload. ### Viewing Secure Media * The secure-media-upload URL will take the post that the upload is attached to into account via `Guardian.can_see?` for access permissions * If there is no `access_control_post` then we just deliver the media. This should be a rare occurrance and shouldn't cause issues as the `access_control_post` is set when `link_post_uploads` is called via `CookedPostProcessor` ### Removed We no longer do any of these because we do not reuse uploads by sha1 if secure media is enabled. * We no longer have a way to prevent cross-posting of a secure upload from a private context to a public context. * We no longer have to set `secure: false` for uploads when uploading for a theme component.
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end
private
def access_control_post
@access_control_post ||=
@upload.access_control_post_id.present? ? @upload.access_control_post : nil
end
def insecure_context_checks
{
secure_uploads_disabled: "secure uploads is disabled",
insecure_creation_for_modifiers: "one or more creation for_modifiers was satisfied",
public_type: "upload is public type",
regular_emoji: "upload is used for regular emoji",
publicly_referenced_first: "upload was publicly referenced when it was first created",
}
end
def secure_context_checks
{
login_required: "login is required",
access_control_post_has_secure_uploads: "access control post dictates security",
secure_creation_for_modifiers: "one or more creation for_modifiers was satisfied",
uploading_in_composer: "uploading via the composer",
already_secure: "upload is already secure",
}
end
# The access control check is important because that is the truest indicator
# of whether an upload should be secure or not, and thus should be returned
# immediately if there is an access control post.
def priority_check?(check)
check == :access_control_post_has_secure_uploads && access_control_post
end
def perform_check(check)
send("#{check}_check")
end
#### START PUBLIC CHECKS ####
def secure_uploads_disabled_check
!SiteSetting.secure_uploads?
FEATURE: Secure media allowing duplicated uploads with category-level privacy and post-based access rules (#8664) ### General Changes and Duplication * We now consider a post `with_secure_media?` if it is in a read-restricted category. * When uploading we now set an upload's secure status straight away. * When uploading if `SiteSetting.secure_media` is enabled, we do not check to see if the upload already exists using the `sha1` digest of the upload. The `sha1` column of the upload is filled with a `SecureRandom.hex(20)` value which is the same length as `Upload::SHA1_LENGTH`. The `original_sha1` column is filled with the _real_ sha1 digest of the file. * Whether an upload `should_be_secure?` is now determined by whether the `access_control_post` is `with_secure_media?` (if there is no access control post then we leave the secure status as is). * When serializing the upload, we now cook the URL if the upload is secure. This is so it shows up correctly in the composer preview, because we set secure status on upload. ### Viewing Secure Media * The secure-media-upload URL will take the post that the upload is attached to into account via `Guardian.can_see?` for access permissions * If there is no `access_control_post` then we just deliver the media. This should be a rare occurrance and shouldn't cause issues as the `access_control_post` is set when `link_post_uploads` is called via `CookedPostProcessor` ### Removed We no longer do any of these because we do not reuse uploads by sha1 if secure media is enabled. * We no longer have a way to prevent cross-posting of a secure upload from a private context to a public context. * We no longer have to set `secure: false` for uploads when uploading for a theme component.
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end
def insecure_creation_for_modifiers_check
return false if !@creating
@upload.for_theme || @upload.for_site_setting || @upload.for_gravatar
end
def public_type_check
PUBLIC_TYPES.include?(@upload_type) || @@custom_public_types.include?(@upload_type)
end
def publicly_referenced_first_check
return false if @creating
first_reference =
@upload
.upload_references
.joins(<<~SQL)
LEFT JOIN posts ON upload_references.target_type = 'Post' AND upload_references.target_id = posts.id
SQL
.where("posts.deleted_at IS NULL")
.order("upload_references.created_at ASC, upload_references.id ASC")
.first
return false if first_reference.blank?
PUBLIC_UPLOAD_REFERENCE_TYPES.include?(first_reference.target_type)
end
def regular_emoji_check
return false if @upload.origin.blank?
uri = URI.parse(@upload.origin)
return true if Emoji.all.map(&:url).include?("#{uri.path}?#{uri.query}")
uri.path.include?("images/emoji")
end
#### END PUBLIC CHECKS ####
#--------------------------#
#### START PRIVATE CHECKS ####
def login_required_check
SiteSetting.login_required? && !SiteSetting.secure_uploads_pm_only?
end
# Whether the upload should remain secure or not after posting depends on its context,
FEATURE: Secure media allowing duplicated uploads with category-level privacy and post-based access rules (#8664) ### General Changes and Duplication * We now consider a post `with_secure_media?` if it is in a read-restricted category. * When uploading we now set an upload's secure status straight away. * When uploading if `SiteSetting.secure_media` is enabled, we do not check to see if the upload already exists using the `sha1` digest of the upload. The `sha1` column of the upload is filled with a `SecureRandom.hex(20)` value which is the same length as `Upload::SHA1_LENGTH`. The `original_sha1` column is filled with the _real_ sha1 digest of the file. * Whether an upload `should_be_secure?` is now determined by whether the `access_control_post` is `with_secure_media?` (if there is no access control post then we leave the secure status as is). * When serializing the upload, we now cook the URL if the upload is secure. This is so it shows up correctly in the composer preview, because we set secure status on upload. ### Viewing Secure Media * The secure-media-upload URL will take the post that the upload is attached to into account via `Guardian.can_see?` for access permissions * If there is no `access_control_post` then we just deliver the media. This should be a rare occurrance and shouldn't cause issues as the `access_control_post` is set when `link_post_uploads` is called via `CookedPostProcessor` ### Removed We no longer do any of these because we do not reuse uploads by sha1 if secure media is enabled. * We no longer have a way to prevent cross-posting of a secure upload from a private context to a public context. * We no longer have to set `secure: false` for uploads when uploading for a theme component.
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# which is based on the post it is linked to via access_control_post_id.
#
# If that post is with_secure_uploads? then the upload should also be secure.
#
# This may change to false if the upload was set to secure on upload e.g. in
# a post composer then it turned out that the post itself was not in a secure context.
#
# A post is with secure uploads if it is a private message or in a read restricted
# category. See `Post#with_secure_uploads?` for the full definition.
def access_control_post_has_secure_uploads_check
access_control_post&.with_secure_uploads?
FEATURE: Secure media allowing duplicated uploads with category-level privacy and post-based access rules (#8664) ### General Changes and Duplication * We now consider a post `with_secure_media?` if it is in a read-restricted category. * When uploading we now set an upload's secure status straight away. * When uploading if `SiteSetting.secure_media` is enabled, we do not check to see if the upload already exists using the `sha1` digest of the upload. The `sha1` column of the upload is filled with a `SecureRandom.hex(20)` value which is the same length as `Upload::SHA1_LENGTH`. The `original_sha1` column is filled with the _real_ sha1 digest of the file. * Whether an upload `should_be_secure?` is now determined by whether the `access_control_post` is `with_secure_media?` (if there is no access control post then we leave the secure status as is). * When serializing the upload, we now cook the URL if the upload is secure. This is so it shows up correctly in the composer preview, because we set secure status on upload. ### Viewing Secure Media * The secure-media-upload URL will take the post that the upload is attached to into account via `Guardian.can_see?` for access permissions * If there is no `access_control_post` then we just deliver the media. This should be a rare occurrance and shouldn't cause issues as the `access_control_post` is set when `link_post_uploads` is called via `CookedPostProcessor` ### Removed We no longer do any of these because we do not reuse uploads by sha1 if secure media is enabled. * We no longer have a way to prevent cross-posting of a secure upload from a private context to a public context. * We no longer have to set `secure: false` for uploads when uploading for a theme component.
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end
def uploading_in_composer_check
@upload_type == "composer"
FEATURE: Secure media allowing duplicated uploads with category-level privacy and post-based access rules (#8664) ### General Changes and Duplication * We now consider a post `with_secure_media?` if it is in a read-restricted category. * When uploading we now set an upload's secure status straight away. * When uploading if `SiteSetting.secure_media` is enabled, we do not check to see if the upload already exists using the `sha1` digest of the upload. The `sha1` column of the upload is filled with a `SecureRandom.hex(20)` value which is the same length as `Upload::SHA1_LENGTH`. The `original_sha1` column is filled with the _real_ sha1 digest of the file. * Whether an upload `should_be_secure?` is now determined by whether the `access_control_post` is `with_secure_media?` (if there is no access control post then we leave the secure status as is). * When serializing the upload, we now cook the URL if the upload is secure. This is so it shows up correctly in the composer preview, because we set secure status on upload. ### Viewing Secure Media * The secure-media-upload URL will take the post that the upload is attached to into account via `Guardian.can_see?` for access permissions * If there is no `access_control_post` then we just deliver the media. This should be a rare occurrance and shouldn't cause issues as the `access_control_post` is set when `link_post_uploads` is called via `CookedPostProcessor` ### Removed We no longer do any of these because we do not reuse uploads by sha1 if secure media is enabled. * We no longer have a way to prevent cross-posting of a secure upload from a private context to a public context. * We no longer have to set `secure: false` for uploads when uploading for a theme component.
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end
def secure_creation_for_modifiers_check
return false if !@creating
@upload.for_private_message || @upload.for_group_message
FEATURE: Secure media allowing duplicated uploads with category-level privacy and post-based access rules (#8664) ### General Changes and Duplication * We now consider a post `with_secure_media?` if it is in a read-restricted category. * When uploading we now set an upload's secure status straight away. * When uploading if `SiteSetting.secure_media` is enabled, we do not check to see if the upload already exists using the `sha1` digest of the upload. The `sha1` column of the upload is filled with a `SecureRandom.hex(20)` value which is the same length as `Upload::SHA1_LENGTH`. The `original_sha1` column is filled with the _real_ sha1 digest of the file. * Whether an upload `should_be_secure?` is now determined by whether the `access_control_post` is `with_secure_media?` (if there is no access control post then we leave the secure status as is). * When serializing the upload, we now cook the URL if the upload is secure. This is so it shows up correctly in the composer preview, because we set secure status on upload. ### Viewing Secure Media * The secure-media-upload URL will take the post that the upload is attached to into account via `Guardian.can_see?` for access permissions * If there is no `access_control_post` then we just deliver the media. This should be a rare occurrance and shouldn't cause issues as the `access_control_post` is set when `link_post_uploads` is called via `CookedPostProcessor` ### Removed We no longer do any of these because we do not reuse uploads by sha1 if secure media is enabled. * We no longer have a way to prevent cross-posting of a secure upload from a private context to a public context. * We no longer have to set `secure: false` for uploads when uploading for a theme component.
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end
def already_secure_check
@upload.secure?
end
#### END PRIVATE CHECKS ####
FEATURE: Secure media allowing duplicated uploads with category-level privacy and post-based access rules (#8664) ### General Changes and Duplication * We now consider a post `with_secure_media?` if it is in a read-restricted category. * When uploading we now set an upload's secure status straight away. * When uploading if `SiteSetting.secure_media` is enabled, we do not check to see if the upload already exists using the `sha1` digest of the upload. The `sha1` column of the upload is filled with a `SecureRandom.hex(20)` value which is the same length as `Upload::SHA1_LENGTH`. The `original_sha1` column is filled with the _real_ sha1 digest of the file. * Whether an upload `should_be_secure?` is now determined by whether the `access_control_post` is `with_secure_media?` (if there is no access control post then we leave the secure status as is). * When serializing the upload, we now cook the URL if the upload is secure. This is so it shows up correctly in the composer preview, because we set secure status on upload. ### Viewing Secure Media * The secure-media-upload URL will take the post that the upload is attached to into account via `Guardian.can_see?` for access permissions * If there is no `access_control_post` then we just deliver the media. This should be a rare occurrance and shouldn't cause issues as the `access_control_post` is set when `link_post_uploads` is called via `CookedPostProcessor` ### Removed We no longer do any of these because we do not reuse uploads by sha1 if secure media is enabled. * We no longer have a way to prevent cross-posting of a secure upload from a private context to a public context. * We no longer have to set `secure: false` for uploads when uploading for a theme component.
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end