Module: ActiveStorageEncryption::PrivateUrlPolicy

Included in:
EncryptedDiskService, EncryptedGCSService, EncryptedS3Service
Defined in:
lib/active_storage_encryption/private_url_policy.rb

Constant Summary collapse

DEFAULT_POLICY = 
:stream

Instance Method Summary collapse

Instance Method Details

#initialize(private_url_policy: DEFAULT_POLICY, **any_other_options_for_service) ⇒ Object 



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# File 'lib/active_storage_encryption/private_url_policy.rb', line 6

def initialize(private_url_policy: DEFAULT_POLICY, **any_other_options_for_service)
  self.private_url_policy = private_url_policy.to_sym
  super(**any_other_options_for_service)
end

#private_url_for_streaming_via_controller(key, expires_in:, filename:, content_type:, disposition:, encryption_key:, blob_byte_size:) ⇒ Object 



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# File 'lib/active_storage_encryption/private_url_policy.rb', line 21

def private_url_for_streaming_via_controller(key, expires_in:, filename:, content_type:, disposition:, encryption_key:, blob_byte_size:)
  if private_url_policy == :disable
    raise ActiveStorageEncryption::StreamingDisabled, <<~EOS
      Requested a signed GET URL for #{key.inspect} on service #{name}. This service
      has disabled presigned URLs (private_url_policy: disable), you have to use `Blob#download` instead.
    EOS
  end
  # This method requires the "blob_byte_size" because it is needed for HTTP ranges (you need to know the range of a resource),
  # The ActiveStorage::ProxyController retrieves the blob from the DB for that, but we can embed it right in the token.
  content_disposition = content_disposition_with(type: disposition, filename: filename)
  verified_key_with_expiration = ActiveStorageEncryption.token_encryptor.encrypt_and_sign(
    {
      key: key,
      disposition: content_disposition,
      encryption_key_sha256: Digest::SHA256.base64digest(encryption_key),
      content_type: content_type,
      service_name: name,
      blob_byte_size: blob_byte_size,
      encryption_key: Base64.strict_encode64(encryption_key)
    },
    expires_in: expires_in,
    purpose: :encrypted_get
  )

  # Both url_helpers and url_options are on the DiskService, but we need them here for other Services too
  url_helpers = ActiveStorageEncryption::Engine.routes.url_helpers
  url_options = ActiveStorage::Current.url_options

  if url_options.blank?
    raise ArgumentError, "Cannot generate URL for #{filename} because ActiveStorage::Current.url_options is not set"
  end

  url_helpers.encrypted_blob_streaming_get_url(verified_key_with_expiration, filename: filename, **url_options)
end

#private_url_policy ⇒ Object 



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# File 'lib/active_storage_encryption/private_url_policy.rb', line 17

def private_url_policy
  @private_url_policy
end

#private_url_policy=(new_value) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/active_storage_encryption/private_url_policy.rb', line 11

def private_url_policy=(new_value)
  allowed = [:disable, :require_headers, :stream]
  raise ArgumentError, "private_url_policy: must be one of #{allowed.join(",")}" unless allowed.include?(new_value.to_sym)
  @private_url_policy = new_value.to_sym
end