class Gem::Security::Policy

# File lib/rubygems/security/policy.rb, line 22
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

# File lib/rubygems/security/policy.rb, line 83
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

# File lib/rubygems/security/policy.rb, line 53
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

# File lib/rubygems/security/policy.rb, line 72
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

# File lib/rubygems/security/policy.rb, line 109
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

# File lib/rubygems/security/policy.rb, line 127
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

# File lib/rubygems/security/policy.rb, line 146
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"

    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

# File lib/rubygems/security/policy.rb, line 193
def verify chain, key = nil, digests = {}, signatures = {}
  if @only_signed and signatures.empty? then
    raise Gem::Security::Exception,
      "unsigned gems are not allowed by the #{name} policy"
  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

  check_trust chain, digester, trust_dir if @only_trusted

  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

# File lib/rubygems/security/policy.rb, line 250
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

  true
end