I'm developing an alternative method for login via certificate, without needing java or a specific language, just http and php to process backend information (but that could be handled by any other language that processes http). The most common methods that exist are the , but it has a low interoperability limiting itself to languages such as .NET and Java. In addition, this method depends on their web-service in order to obtain the certificate's CPF, in case the system is out, it is not possible to protect the user.
We know that you can request the #, which enables the web server to open a request the client certificate within a pre-selected certificate chain , which will do exactly what Certsign does.
We have already requested an e-CPF and an e-CNOJ, the question is, where within the public data of the certificate are the information regarding the number of cpf or cnpj?