
module Gem::Security

  ##
  # No security policy: all package signature checks are disabled.

  NoSecurity = Policy.new(
    'No Security',
    :verify_data      => false,
    :verify_signer    => false,
    :verify_chain     => false,
    :verify_root      => false,
    :only_trusted     => false,
    :only_signed      => false
  )

  ##
  # AlmostNo security policy: only verify that the signing certificate is the
  # one that actually signed the data.  Make no attempt to verify the signing
  # certificate chain.
  #
  # This policy is basically useless. better than nothing, but can still be
  # easily spoofed, and is not recommended.

  AlmostNoSecurity = Policy.new(
    'Almost No Security',
    :verify_data      => true,
    :verify_signer    => false,
    :verify_chain     => false,
    :verify_root      => false,
    :only_trusted     => false,
    :only_signed      => false
  )

  ##
  # Low security policy: only verify that the signing certificate is actually
  # the gem signer, and that the signing certificate is valid.
  #
  # This policy is better than nothing, but can still be easily spoofed, and
  # is not recommended.

  LowSecurity = Policy.new(
    'Low Security',
    :verify_data      => true,
    :verify_signer    => true,
    :verify_chain     => false,
    :verify_root      => false,
    :only_trusted     => false,
    :only_signed      => false
  )

  ##
  # Medium security policy: verify the signing certificate, verify the signing
  # certificate chain all the way to the root certificate, and only trust root
  # certificates that we have explicitly allowed trust for.
  #
  # This security policy is reasonable, but it allows unsigned packages, so a
  # malicious person could simply delete the package signature and pass the
  # gem off as unsigned.

  MediumSecurity = Policy.new(
    'Medium Security',
    :verify_data      => true,
    :verify_signer    => true,
    :verify_chain     => true,
    :verify_root      => true,
    :only_trusted     => true,
    :only_signed      => false
  )

  ##
  # High security policy: only allow signed gems to be installed, verify the
  # signing certificate, verify the signing certificate chain all the way to
  # the root certificate, and only trust root certificates that we have
  # explicitly allowed trust for.
  #
  # This security policy is significantly more difficult to bypass, and offers
  # a reasonable guarantee that the contents of the gem have not been altered.

  HighSecurity = Policy.new(
    'High Security',
    :verify_data      => true,
    :verify_signer    => true,
    :verify_chain     => true,
    :verify_root      => true,
    :only_trusted     => true,
    :only_signed      => true
  )

  ##
  # Policy used to verify a certificate and key when signing a gem

  SigningPolicy = Policy.new(
    'Signing Policy',
    :verify_data      => false,
    :verify_signer    => true,
    :verify_chain     => true,
    :verify_root      => true,
    :only_trusted     => false,
    :only_signed      => false
  )

  ##
  # Hash of configured security policies

  Policies = {
    'NoSecurity'       => NoSecurity,
    'AlmostNoSecurity' => AlmostNoSecurity,
    'LowSecurity'      => LowSecurity,
    'MediumSecurity'   => MediumSecurity,
    'HighSecurity'     => HighSecurity,
    # SigningPolicy is not intended for use by `gem -P` so do not list it
  }

end