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class ActionDispatch::ContentSecurityPolicy

Action Dispatch Content Security Policy

Configures the HTTP [Content-Security-Policy] (developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy) response header to help protect against XSS and injection attacks.

Example global policy:

Rails.application.config.content_security_policy do |policy|
  policy.default_src :self, :https
  policy.font_src    :self, :https, :data
  policy.img_src     :self, :https, :data
  policy.object_src  :none
  policy.script_src  :self, :https
  policy.style_src   :self, :https

  # Specify URI for violation reports
  policy.report_uri "/csp-violation-report-endpoint"
end

Attributes

[R] directives

Public class methods

Source code GitHub
# File actionpack/lib/action_dispatch/http/content_security_policy.rb, line 177
def initialize
  @directives = {}
  yield self if block_given?
end

Public instance methods

Specify whether to prevent the user agent from loading any assets over HTTP when the page uses HTTPS:

policy.block_all_mixed_content

Pass false to allow it again:

policy.block_all_mixed_content false
Source code GitHub
# File actionpack/lib/action_dispatch/http/content_security_policy.rb, line 205
def block_all_mixed_content(enabled = true)
  if enabled
    @directives["block-all-mixed-content"] = true
  else
    @directives.delete("block-all-mixed-content")
  end
end
Source code GitHub
# File actionpack/lib/action_dispatch/http/content_security_policy.rb, line 297
def build(context = nil, nonce = nil, nonce_directives = nil)
  nonce_directives = DEFAULT_NONCE_DIRECTIVES if nonce_directives.nil?
  build_directives(context, nonce, nonce_directives).compact.join("; ")
end
Source code GitHub
# File actionpack/lib/action_dispatch/http/content_security_policy.rb, line 182
def initialize_copy(other)
  @directives = other.directives.deep_dup
end

Restricts the set of plugins that can be embedded:

policy.plugin_types "application/x-shockwave-flash"

Leave empty to allow all plugins:

policy.plugin_types
Source code GitHub
# File actionpack/lib/action_dispatch/http/content_security_policy.rb, line 221
def plugin_types(*types)
  if types.first
    @directives["plugin-types"] = types
  else
    @directives.delete("plugin-types")
  end
end

Enable the [report-uri] (developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy/report-uri) directive. Violation reports will be sent to the specified URI:

policy.report_uri "/csp-violation-report-endpoint"
Source code GitHub
# File actionpack/lib/action_dispatch/http/content_security_policy.rb, line 236
def report_uri(uri)
  @directives["report-uri"] = [uri]
end

Specify asset types for which [Subresource Integrity] (developer.mozilla.org/en-US/docs/Web/Security/Subresource_Integrity) is required:

policy.require_sri_for :script, :style

Leave empty to not require Subresource Integrity:

policy.require_sri_for
Source code GitHub
# File actionpack/lib/action_dispatch/http/content_security_policy.rb, line 249
def require_sri_for(*types)
  if types.first
    @directives["require-sri-for"] = types
  else
    @directives.delete("require-sri-for")
  end
end

Specify whether a [sandbox] (developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy/sandbox) should be enabled for the requested resource:

policy.sandbox

Values can be passed as arguments:

policy.sandbox "allow-scripts", "allow-modals"

Pass false to disable the sandbox:

policy.sandbox false
Source code GitHub
# File actionpack/lib/action_dispatch/http/content_security_policy.rb, line 271
def sandbox(*values)
  if values.empty?
    @directives["sandbox"] = true
  elsif values.first
    @directives["sandbox"] = values
  else
    @directives.delete("sandbox")
  end
end

Specify whether user agents should treat any assets over HTTP as HTTPS:

policy.upgrade_insecure_requests

Pass false to disable it:

policy.upgrade_insecure_requests false
Source code GitHub
# File actionpack/lib/action_dispatch/http/content_security_policy.rb, line 289
def upgrade_insecure_requests(enabled = true)
  if enabled
    @directives["upgrade-insecure-requests"] = true
  else
    @directives.delete("upgrade-insecure-requests")
  end
end

Namespace

Definition files