debian-mirror-gitlab/lib/gitlab/x509/signature.rb
2020-04-22 19:07:51 +05:30

198 lines
5.2 KiB
Ruby

# frozen_string_literal: true
require 'openssl'
require 'digest'
module Gitlab
module X509
class Signature
include Gitlab::Utils::StrongMemoize
attr_reader :signature_text, :signed_text, :created_at
def initialize(signature_text, signed_text, email, created_at)
@signature_text = signature_text
@signed_text = signed_text
@email = email
@created_at = created_at
end
def x509_certificate
return if certificate_attributes.nil?
X509Certificate.safe_create!(certificate_attributes) unless verified_signature.nil?
end
def verified_signature
strong_memoize(:verified_signature) { verified_signature? }
end
def verification_status
return :unverified if x509_certificate.nil? || x509_certificate.revoked?
if verified_signature && certificate_email == @email
:verified
else
:unverified
end
end
private
def cert
strong_memoize(:cert) do
signer_certificate(p7) if valid_signature?
end
end
def cert_store
strong_memoize(:cert_store) do
store = OpenSSL::X509::Store.new
store.set_default_paths
# valid_signing_time? checks the time attributes already
# this flag is required, otherwise expired certificates would become
# unverified when notAfter within certificate attribute is reached
store.flags = OpenSSL::X509::V_FLAG_NO_CHECK_TIME
store
end
end
def p7
strong_memoize(:p7) do
pkcs7_text = signature_text.sub('-----BEGIN SIGNED MESSAGE-----', '-----BEGIN PKCS7-----')
pkcs7_text = pkcs7_text.sub('-----END SIGNED MESSAGE-----', '-----END PKCS7-----')
OpenSSL::PKCS7.new(pkcs7_text)
rescue
nil
end
end
def valid_signing_time?
# rfc 5280 - 4.1.2.5 Validity
# check if signed_time is within the time range (notBefore/notAfter)
# non-rfc - git specific check: signed_time >= commit_time
p7.signers[0].signed_time.between?(cert.not_before, cert.not_after) &&
p7.signers[0].signed_time >= created_at
end
def valid_signature?
p7.verify([], cert_store, signed_text, OpenSSL::PKCS7::NOVERIFY)
rescue
nil
end
def verified_signature?
# verify has multiple options but only a boolean return value
# so first verify without certificate chain
if valid_signature?
if valid_signing_time?
# verify with system certificate chain
p7.verify([], cert_store, signed_text)
else
false
end
else
nil
end
rescue
nil
end
def signer_certificate(p7)
p7.certificates.each do |cert|
next if cert.serial != p7.signers[0].serial
return cert
end
end
def certificate_crl
extension = get_certificate_extension('crlDistributionPoints')
return if extension.nil?
crl_url = nil
extension.each_line do |line|
break if crl_url
line.split('URI:').each do |item|
item.strip
if item.start_with?("http")
crl_url = item.strip
break
end
end
end
crl_url
end
def get_certificate_extension(extension)
ext = cert.extensions.detect { |ext| ext.oid == extension }
ext&.value
end
def issuer_subject_key_identifier
key_identifier = get_certificate_extension('authorityKeyIdentifier')
return if key_identifier.nil?
key_identifier.gsub("keyid:", "").delete!("\n")
end
def certificate_subject_key_identifier
key_identifier = get_certificate_extension('subjectKeyIdentifier')
return if key_identifier.nil?
key_identifier
end
def certificate_issuer
cert.issuer.to_s(OpenSSL::X509::Name::RFC2253)
end
def certificate_subject
cert.subject.to_s(OpenSSL::X509::Name::RFC2253)
end
def certificate_email
email = nil
get_certificate_extension('subjectAltName').split(',').each do |item|
if item.strip.start_with?("email")
email = item.split('email:')[1]
break
end
end
return if email.nil?
email
end
def x509_issuer
return if verified_signature.nil? || issuer_subject_key_identifier.nil? || certificate_crl.nil?
attributes = {
subject_key_identifier: issuer_subject_key_identifier,
subject: certificate_issuer,
crl_url: certificate_crl
}
X509Issuer.safe_create!(attributes) unless verified_signature.nil?
end
def certificate_attributes
return if verified_signature.nil? || certificate_subject_key_identifier.nil? || x509_issuer.nil?
{
subject_key_identifier: certificate_subject_key_identifier,
subject: certificate_subject,
email: certificate_email,
serial_number: cert.serial.to_i,
x509_issuer_id: x509_issuer.id
}
end
end
end
end