检查证书是否被吊销可能是一个复杂的过程。首先,您必须查找 CDP 或 OCSP AIA,然后发出请求,解析响应,并检查响应是否由授权响应相关证书的 CA 签署。如果它是 CRL,那么您需要查看您正在检查的证书的序列号是否存在于列表中。如果是 OCSP,那么您需要查看是否收到了“良好”响应(与未知、已撤销或任何各种 OCSP 响应者错误(如未经授权)相对)。此外,您可能希望验证证书是否在其有效期内并链接到受信任的根。最后,您还应该对每个中间人进行吊销检查并检查证书'
我不知道有任何 Ruby 库可以为您自动执行吊销检查过程(最终我希望将其添加到r509),但考虑到您更具体的用例,这里有一些未经测试的代码应该为您指明正确的方向。
require 'r509'
require 'net/http'
cert = R509::Cert.load_from_file("some_iphone_cert.pem")
crl_uri = cert.crl_distribution_points.crl.uris[0]
crl = Net::HTTP.get_response(URI(crl_uri)) # you may need to follow redirects here, but let's assume you got the CRL.
# Also note that the Apple WWDRCA CRL is like 28MB so you may want to cache this damned thing. OCSP would be nicer but it's a bit trickier to validate.
parsed_crl = R509::CRL::SignedList.new(crl)
if not parsed_crl.verify(cert.public_key)
raise StandardError, "Invalid CRL for certificate"
end
if parsed_crl.revoked?(cert.serial)
puts 'revoked'
end
不幸的是,由于 Apple WWDRCA CRL 的巨大尺寸(约 680k 条目),对于 r509 的当前哈希映射模型,此检查可能会非常慢。
如果您对 OCSP 路径感兴趣,我也可以写下如何在 Ruby 中生成 OCSP 请求/解析响应。
编辑:似乎我拥有的 iPhone 开发人员证书不包含嵌入式 OCSP AIA,因此吊销检查的唯一选择是通过 CRL 分发点,如上所述。
Edit2:哦,为什么不呢,让我们在 Ruby 中进行 OCSP 检查!为此,我们需要证书及其颁发证书。您不能为此使用 WWDRCA 证书,因此只需从您最喜欢的网站上获取一个。我正在使用我自己的网站。
require 'net/http'
require 'r509'
cert = R509::Cert.load_from_file("my_website.pem")
# get the first OCSP AIA URI. There can be more than one
# (degenerate example!)
ocsp_uri = cert.aia.ocsp.uris[0]
issuer = R509::Cert.load_from_file("my_issuer.pem")
cert_id = OpenSSL::OCSP::CertificateId.new(cert.cert,issuer.cert)
request = OpenSSL::OCSP::Request.new
request.add_certid(cert_id)
# we're going to make a GET request per RFC 5019. You can also POST the
# binary DER encoded version if you're more of an RFC 2560 partisan
request_uri = URI(ocsp_uri+"/"+URI.encode_www_form_component(req_pem.strip)
http_response = Net::HTTP.get_response(request_uri)
if http_response.code != "200"
raise StandardError, "Invalid response code from OCSP responder"
end
response = OpenSSL::OCSP::Response.new(http_response.body)
if response.status != 0
raise StandardError, "Not a successful status"
end
if response.basic[0][0].serial != cert.serial
raise StandardError, "Not the same serial"
end
if response.basic[0][1] != 0 # 0 is good, 1 is revoked, 2 is unknown.
raise StandardError, "Not a good status"
end
current_time = Time.now
if response.basic[0][4] > current_time or response.basic[0][5] < current_time
raise StandardError, "The response is not within its validity window"
end
# we also need to verify that the OCSP response is signed by
# a certificate that is allowed and chains up to a trusted root.
# To do this you'll need to build an OpenSSL::X509::Store object
# that contains the certificate you're checking + intermediates + root.
store = OpenSSL::X509::Store.new
store.add_cert(cert.cert)
store.add_cert(issuer.cert) #assuming issuer is a trusted root here, but in reality you'll need at least one more certificate
if response.basic.verify([],store) != true
raise StandardError, "Certificate verification error"
end
上面的示例代码忽略了处理许多可能的边缘情况,所以它应该被认为只是一个起点。祝你好运!