Class: Kotoshu::Integrity::Manifest

Inherits:
Object
  • Object
show all
Defined in:
lib/kotoshu/integrity/manifest.rb

Overview

Parsed view of a content repo's manifest.json.

Format (per TODO.impl/09-integrity-security.md task 1):

{
"version": 1,
"generated_at": "2026-06-25T10:00:00Z",
"resources": {
  "en/spelling/index.dic": {
    "size": 49568,
    "sha256": "ab12...",
    "language": "en",
    "type": "spelling",
    "license": "LGPL/MPL/GPL",
    "source": "SCROLL"
  }
}
}

Construction:

manifest = Manifest.parse(json_string)
manifest.fetch("en/spelling/index.dic")  # => Entry or nil
manifest.verify_content!("en/spelling/index.dic", bytes) # raises on mismatch

Manifest.load(url, http:), returns nil when the manifest 404s (graceful degradation — see module docs).

Defined Under Namespace

Classes: Entry

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(entries, version: nil, generated_at: nil) ⇒ Manifest

Returns a new instance of Manifest.



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# File 'lib/kotoshu/integrity/manifest.rb', line 81

def initialize(entries, version: nil, generated_at: nil)
  @entries = entries
  @version = version
  @generated_at = generated_at
end

Instance Attribute Details

#entries ⇒ Object (readonly)

Returns the value of attribute entries.



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# File 'lib/kotoshu/integrity/manifest.rb', line 79

def entries
  @entries
end

#generated_at ⇒ Object (readonly)

Returns the value of attribute generated_at.



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# File 'lib/kotoshu/integrity/manifest.rb', line 79

def generated_at
  @generated_at
end

#version ⇒ Object (readonly)

Returns the value of attribute version.



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# File 'lib/kotoshu/integrity/manifest.rb', line 79

def version
  @version
end

Class Method Details

.load(url, http: Kotoshu::Integrity::NetHTTP) ⇒ Object

Fetch and parse a manifest from a URL. Returns nil when the manifest is absent (HTTP 404/410) so callers can fall back to unverified downloads — see module docs. Any other failure (5xx, network error, parse error) raises.



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# File 'lib/kotoshu/integrity/manifest.rb', line 72

def self.load(url, http: Kotoshu::Integrity::NetHTTP)
  body = http.get(url)
  return nil if body.nil?

  parse(body)
end

.parse(json) ⇒ Object

Parse a manifest JSON string. Returns an empty Manifest if the JSON is parseable but has no resources (caller treats as "no constraints").



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# File 'lib/kotoshu/integrity/manifest.rb', line 45

def self.parse(json)
  data = JSON.parse(json)
  entries = {}
  (data["resources"] || {}).each do |path, fields|
    entries[path] = Entry.new(
      path: path,
      sha256: fields["sha256"],
      size: fields["size"],
      language: fields["language"],
      type: fields["type"],
      license: fields["license"],
      source: fields["source"]
    )
  end
  new(entries, version: data["version"], generated_at: data["generated_at"])
rescue JSON::ParserError => e
  raise Kotoshu::IntegrityError.new(
    "manifest",
    expected: "<valid JSON>",
    actual: "<parse error: #{e.message}>"
  )
end

Instance Method Details

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/kotoshu/integrity/manifest.rb', line 91

def empty?
  @entries.empty?
end

#fetch(path) ⇒ Object 



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# File 'lib/kotoshu/integrity/manifest.rb', line 87

def fetch(path)
  @entries[path]
end

#verify_content!(path, content, url: nil) ⇒ Object

Verify that content for path matches the manifest entry. Raises Kotoshu::IntegrityError on mismatch. No-op when the manifest has no entry for path (returns nil — caller decides whether to treat absence as failure in strict mode).



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# File 'lib/kotoshu/integrity/manifest.rb', line 99

def verify_content!(path, content, url: nil)
  entry = @entries[path]
  return nil unless entry

  actual = Digest::SHA256.hexdigest(content)
  unless actual == entry.sha256
    raise Kotoshu::IntegrityError.new(
      path,
      expected: entry.sha256,
      actual: actual,
      url: url
    )
  end
  true
end