##
# Basic OpenSSL-based package signing class.
class Gem::Security::Signer
##
# The chain of certificates for signing including the signing certificate
attr_accessor :cert_chain
##
# The private key for the signing certificate
attr_accessor :key
##
# The digest algorithm used to create the signature
attr_reader :digest_algorithm
##
# The name of the digest algorithm, used to pull digests out of the hash by
# name.
attr_reader :digest_name # :nodoc:
##
# Creates a new signer with an RSA +key+ or path to a key, and a certificate
# +chain+ containing X509 certificates, encoding certificates or paths to
# certificates.
def initialize key, cert_chain, passphrase = nil
@cert_chain = cert_chain
@key = key
unless @key then
default_key = File.join Gem.default_key_path
@key = default_key if File.exist? default_key
end
unless @cert_chain then
default_cert = File.join Gem.default_cert_path
@cert_chain = [default_cert] if File.exist? default_cert
end
@digest_algorithm = Gem::Security::DIGEST_ALGORITHM
@digest_name = Gem::Security::DIGEST_NAME
@key = OpenSSL::PKey::RSA.new File.read(@key), passphrase if
@key and not OpenSSL::PKey::RSA === @key
if @cert_chain then
@cert_chain = @cert_chain.compact.map do |cert|
next cert if OpenSSL::X509::Certificate === cert
cert = File.read cert if File.exist? cert
OpenSSL::X509::Certificate.new cert
end
load_cert_chain
end
end
##
# Extracts the full name of +cert+. If the certificate has a subjectAltName
# this value is preferred, otherwise the subject is used.
def extract_name cert # :nodoc:
subject_alt_name = cert.extensions.find { |e| 'subjectAltName' == e.oid }
if subject_alt_name then
/\Aemail:/ =~ subject_alt_name.value
$' || subject_alt_name.value
else
cert.subject
end
end
##
# Loads any missing issuers in the cert chain from the trusted certificates.
#
# If the issuer does not exist it is ignored as it will be checked later.
def load_cert_chain # :nodoc:
return if @cert_chain.empty?
while @cert_chain.first.issuer.to_s != @cert_chain.first.subject.to_s do
issuer = Gem::Security.trust_dir.issuer_of @cert_chain.first
break unless issuer # cert chain is verified later
@cert_chain.unshift issuer
end
end
##
# Sign data with given digest algorithm
def sign data
return unless @key
if @cert_chain.length == 1 and @cert_chain.last.not_after < Time.now then
re_sign_key
end
full_name = extract_name @cert_chain.last
Gem::Security::SigningPolicy.verify @cert_chain, @key, {}, {}, full_name
@key.sign @digest_algorithm.new, data
end
##
# Attempts to re-sign the private key if the signing certificate is expired.
#
# The key will be re-signed if:
# * The expired certificate is self-signed
# * The expired certificate is saved at ~/.gem/gem-public_cert.pem
# * There is no file matching the expiry date at
# ~/.gem/gem-public_cert.pem.expired.%Y%m%d%H%M%S
#
# If the signing certificate can be re-signed the expired certificate will
# be saved as ~/.gem/gem-pubilc_cert.pem.expired.%Y%m%d%H%M%S where the
# expiry time (not after) is used for the timestamp.
def re_sign_key # :nodoc:
old_cert = @cert_chain.last
disk_cert_path = File.join Gem.default_cert_path
disk_cert = File.read disk_cert_path rescue nil
disk_key =
File.read File.join(Gem.default_key_path) rescue nil
if disk_key == @key.to_pem and disk_cert == old_cert.to_pem then
expiry = old_cert.not_after.strftime '%Y%m%d%H%M%S'
old_cert_file = "gem-public_cert.pem.expired.#{expiry}"
old_cert_path = File.join Gem.user_home, ".gem", old_cert_file
unless File.exist? old_cert_path then
Gem::Security.write old_cert, old_cert_path
cert = Gem::Security.re_sign old_cert, @key
Gem::Security.write cert, disk_cert_path
@cert_chain = [cert]
end
end
end
end
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