43 lines
1.2 KiB
Ruby
43 lines
1.2 KiB
Ruby
# frozen_string_literal: true
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#
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# Copyright (C) 2012 - present Instructure, Inc.
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#
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# This file is part of Canvas.
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#
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# Canvas is free software: you can redistribute it and/or modify it under
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# the terms of the GNU Affero General Public License as published by the Free
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# Software Foundation, version 3 of the License.
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#
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# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
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# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
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# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
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# details.
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#
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# You should have received a copy of the GNU Affero General Public License along
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# with this program. If not, see <http://www.gnu.org/licenses/>.
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module AssetSignature
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DELIMITER = "-"
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class << self
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def generate(asset)
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"#{asset.id}#{DELIMITER}#{generate_hmac(asset.class, asset.id)}"
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end
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def find_by_signature(klass, signature)
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id, hmac = signature.split(DELIMITER, 2)
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return nil unless Canvas::Security.verify_hmac_sha1(hmac, "#{klass}#{id}", truncate: 8)
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klass.where(id: id.to_i).first
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end
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private
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def generate_hmac(klass, id)
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data = "#{klass}#{id}"
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Canvas::Security.hmac_sha1(data)[0, 8]
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end
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end
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end
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