Class: Gem::Security::Policy

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Instance Chain: self, ::Gem::UserInteraction, ::Gem::DefaultUserInteraction
Inherits:	Object
Defined in:	lib/rubygems/security/policy.rb, lib/rubygems/install_update_options.rb

Overview

A Policy object encapsulates the settings for verifying signed gem files. This is the base class. You can either declare an instance of this or use one of the preset security policies in Policies.

Class Method Summary

.new(name, policy = {}, opt = {}) ⇒ Policy constructor

Create a new Policy object with the given mode and options.

Instance Attribute Summary

#only_signed rw
#only_trusted rw
#verify_chain rw
#verify_data rw
#verify_root rw
#verify_signer rw
#name (also: #to_s) readonly

::Gem::DefaultUserInteraction - Included

#ui	See DefaultUserInteraction.ui
#ui=	See DefaultUserInteraction.ui=

Instance Method Summary

#check_cert(signer, issuer, time)

Ensures that signer is valid for Gem.time and was signed by the issuer.
#check_chain(chain, time)

Verifies each certificate in chain has signed the following certificate and is valid for the given Gem.time.
#check_data(public_key, digest, signature, data)

Verifies that data matches the signature created by public_key and the digest algorithm.
#check_key(signer, key)

Ensures the public key of key matches the public key in signer
#check_root(chain, time)

Ensures the root certificate in chain is self-signed and valid for Gem.time.
#check_trust(chain, digester, trust_dir)

Ensures the root of chain has a trusted certificate in trust_dir and the digests of the two certificates match according to digester
#verify(chain, key = nil, digests = {}, signatures = {}, full_name = '(unknown)')

For full_name, verifies the certificate chain is valid, the digests match the signatures signatures created by the signer depending on the policy settings.
#verify_signatures(spec, digests, signatures)

Extracts the certificate chain from the spec and calls #verify to ensure the signatures and certificate chain is valid according to the policy..

::Gem::UserInteraction - Included

#alert	Displays an alert `statement`.
#alert_error	Displays an error `statement` to the error output location.
#alert_warning	Displays a warning `statement` to the warning output location.
#ask	Asks a `question` and returns the answer.
#ask_for_password	Asks for a password with a `prompt`
#ask_yes_no	Asks a yes or no `question`.
#choose_from_list	Asks the user to answer `question` with an answer from the given `list`.
#say	Displays the given `statement` on the standard output (or equivalent).
#terminate_interaction	Terminates the RubyGems process with the given `exit_code`
#verbose	Calls `say` with `msg` or the results of the block if really_verbose is true.

::Gem::DefaultUserInteraction - Included

#use_ui

See DefaultUserInteraction.use_ui

Constructor Details

.new(name, policy = {}, opt = {}) ⇒ `Policy`

Create a new Policy object with the given mode and options.

[ GitHub ]

# File 'lib/rubygems/security/policy.rb', line 27


def initialize name, policy = {}, opt = {}
  require 'openssl'

  @name = name

  @opt = opt

  # Default to security
  @only_signed   = true
  @only_trusted  = true
  @verify_chain  = true
  @verify_data   = true
  @verify_root   = true
  @verify_signer = true

  policy.each_pair do |key, val|
    case key
    when :verify_data   then @verify_data   = val
    when :verify_signer then @verify_signer = val
    when :verify_chain  then @verify_chain  = val
    when :verify_root   then @verify_root   = val
    when :only_trusted  then @only_trusted  = val
    when :only_signed   then @only_signed   = val
    end
  end
end

Instance Attribute Details

#name (readonly) Also known as: #to_s

[ GitHub ]

# File 'lib/rubygems/security/policy.rb', line 14


attr_reader :name

#only_signed (rw)

[ GitHub ]

# File 'lib/rubygems/security/policy.rb', line 16


attr_accessor :only_signed

#only_trusted (rw)

[ GitHub ]

# File 'lib/rubygems/security/policy.rb', line 17


attr_accessor :only_trusted

#verify_chain (rw)

[ GitHub ]

# File 'lib/rubygems/security/policy.rb', line 18


attr_accessor :verify_chain

#verify_data (rw)

[ GitHub ]

# File 'lib/rubygems/security/policy.rb', line 19


attr_accessor :verify_data

#verify_root (rw)

[ GitHub ]

# File 'lib/rubygems/security/policy.rb', line 20


attr_accessor :verify_root

#verify_signer (rw)

[ GitHub ]

# File 'lib/rubygems/security/policy.rb', line 21


attr_accessor :verify_signer

Instance Method Details

#check_cert(signer, issuer, time)

Ensures that signer is valid for Gem.time and was signed by the issuer. If the issuer is nil no verification is performed.

Raises:

(Gem::Security::Exception)

[ GitHub ]

# File 'lib/rubygems/security/policy.rb', line 88


def check_cert signer, issuer, time
  raise Gem::Security::Exception, 'missing signing certificate' unless
    signer

  message = "certificate #{signer.subject}"

  if not_before = signer.not_before and not_before > time then
    raise Gem::Security::Exception,
          "#{message} not valid before #{not_before}"
  end

  if not_after = signer.not_after and not_after < time then
    raise Gem::Security::Exception, "#{message} not valid after #{not_after}"
  end

  if issuer and not signer.verify issuer.public_key then
    raise Gem::Security::Exception,
          "#{message} was not issued by #{issuer.subject}"
  end

  true
end

#check_chain(chain, time)

Verifies each certificate in chain has signed the following certificate and is valid for the given Gem.time.

Raises:

(Gem::Security::Exception)

[ GitHub ]

# File 'lib/rubygems/security/policy.rb', line 58


def check_chain chain, time
  raise Gem::Security::Exception, 'missing signing chain' unless chain
  raise Gem::Security::Exception, 'empty signing chain' if chain.empty?

  begin
    chain.each_cons 2 do |issuer, cert|
      check_cert cert, issuer, time
    end

    true
  rescue Gem::Security::Exception => e
    raise Gem::Security::Exception, "invalid signing chain: #{e.message}"
  end
end

#check_data(public_key, digest, signature, data)

Verifies that data matches the signature created by public_key and the digest algorithm.

Raises:

(Gem::Security::Exception)

[ GitHub ]

# File 'lib/rubygems/security/policy.rb', line 77


def check_data public_key, digest, signature, data
  raise Gem::Security::Exception, "invalid signature" unless
    public_key.verify digest.new, signature, data.digest

  true
end

#check_key(signer, key)

Ensures the public key of key matches the public key in signer

Raises:

(Gem::Security::Exception)

[ GitHub ]

# File 'lib/rubygems/security/policy.rb', line 114


def check_key signer, key
  unless signer and key then
    return true unless @only_signed

    raise Gem::Security::Exception, 'missing key or signature'
  end

  raise Gem::Security::Exception,
    "certificate #{signer.subject} does not match the signing key" unless
      signer.public_key.to_pem == key.public_key.to_pem

  true
end

#check_root(chain, time)

Ensures the root certificate in chain is self-signed and valid for Gem.time.

Raises:

(Gem::Security::Exception)

[ GitHub ]

# File 'lib/rubygems/security/policy.rb', line 132


def check_root chain, time
  raise Gem::Security::Exception, 'missing signing chain' unless chain

  root = chain.first

  raise Gem::Security::Exception, 'missing root certificate' unless root

  raise Gem::Security::Exception,
        "root certificate #{root.subject} is not self-signed " +
        "(issuer #{root.issuer})" if
    root.issuer.to_s != root.subject.to_s # HACK to_s is for ruby 1.8

  check_cert root, root, time
end

#check_trust(chain, digester, trust_dir)

Ensures the root of chain has a trusted certificate in Gem::Security.trust_dir and the digests of the two certificates match according to digester

Raises:

(Gem::Security::Exception)

[ GitHub ]

# File 'lib/rubygems/security/policy.rb', line 151


def check_trust chain, digester, trust_dir
  raise Gem::Security::Exception, 'missing signing chain' unless chain

  root = chain.first

  raise Gem::Security::Exception, 'missing root certificate' unless root

  path = Gem::Security.trust_dir.cert_path root

  unless File.exist? path then
    message = "root cert #{root.subject} is not trusted".dup

    message << " (root of signing cert #{chain.last.subject})" if
      chain.length > 1

    raise Gem::Security::Exception, message
  end

  save_cert = OpenSSL::X509::Certificate.new File.read path
  save_dgst = digester.digest save_cert.public_key.to_s

  pkey_str = root.public_key.to_s
  cert_dgst = digester.digest pkey_str

  raise Gem::Security::Exception,
        "trusted root certificate #{root.subject} checksum " +
        "does not match signing root certificate checksum" unless
    save_dgst == cert_dgst

  true
end

#verify(chain, key = nil, digests = {}, signatures = {}, full_name = '(unknown)')

For full_name, verifies the certificate chain is valid, the digests match the signatures signatures created by the signer depending on the policy settings.

If key is given it is used to validate the signing certificate.

[ GitHub ]

# File 'lib/rubygems/security/policy.rb', line 211


def verify chain, key = nil, digests = {}, signatures = {},
           full_name = '(unknown)'
  if signatures.empty? then
    if @only_signed then
      raise Gem::Security::Exception,
        "unsigned gems are not allowed by the #{name} policy"
    elsif digests.empty? then
      # lack of signatures is irrelevant if there is nothing to check
      # against
    else
      alert_warning "#{full_name} is not signed"
      return
    end
  end

  opt       = @opt
  digester  = Gem::Security::DIGEST_ALGORITHM
  trust_dir = opt[:trust_dir]
  time      = Time.now

  _, signer_digests = digests.find do |algorithm, file_digests|
    file_digests.values.first.name == Gem::Security::DIGEST_NAME
  end

  if @verify_data then
    raise Gem::Security::Exception, 'no digests provided (probable bug)' if
      signer_digests.nil? or signer_digests.empty?
  else
    signer_digests = {}
  end

  signer = chain.last

  check_key signer, key if key

  check_cert signer, nil, time if @verify_signer

  check_chain chain, time if @verify_chain

  check_root chain, time if @verify_root

  if @only_trusted then
    check_trust chain, digester, trust_dir
  elsif signatures.empty? and digests.empty? then
    # trust is irrelevant if there's no signatures to verify
  else
    alert_warning "#{subject signer} is not trusted for #{full_name}"
  end

  signatures.each do |file, _|
    digest = signer_digests[file]

    raise Gem::Security::Exception, "missing digest for #{file}" unless
      digest
  end

  signer_digests.each do |file, digest|
    signature = signatures[file]

    raise Gem::Security::Exception, "missing signature for #{file}" unless
      signature

    check_data signer.public_key, digester, signature, digest if @verify_data
  end

  true
end

#verify_signatures(spec, digests, signatures)

Extracts the certificate chain from the spec and calls #verify to ensure the signatures and certificate chain is valid according to the policy..

[ GitHub ]

# File 'lib/rubygems/security/policy.rb', line 283


def verify_signatures spec, digests, signatures
  chain = spec.cert_chain.map do |cert_pem|
    OpenSSL::X509::Certificate.new cert_pem
  end

  verify chain, nil, digests, signatures, spec.full_name

  true
end

Class: Gem::Security::Policy

Overview

Class Method Summary

Instance Attribute Summary

::Gem::DefaultUserInteraction - Included

Instance Method Summary

::Gem::UserInteraction - Included

::Gem::DefaultUserInteraction - Included

Constructor Details

.new(name, policy = {}, opt = {}) ⇒ Policy

Instance Attribute Details

#name (readonly) Also known as: #to_s

#only_signed (rw)

#only_trusted (rw)

#verify_chain (rw)

#verify_data (rw)

#verify_root (rw)

#verify_signer (rw)

Instance Method Details

#check_cert(signer, issuer, time)

#check_chain(chain, time)

#check_data(public_key, digest, signature, data)

#check_key(signer, key)

#check_root(chain, time)

#check_trust(chain, digester, trust_dir)

#verify(chain, key = nil, digests = {}, signatures = {}, full_name = '(unknown)')

#verify_signatures(spec, digests, signatures)

.new(name, policy = {}, opt = {}) ⇒ `Policy`