Botan 是一个 C++ 的加密算法库,支持 AES, DES, SHA-1, RSA, DSA, Diffie-Hellman 等多种算法,支持 X.509 认证以及CRLs 和 PKCS #10
botan-demo.c
#include <botan/botan.h>
#include <botan/x509_ca.h>
#include <botan/util.h>
using namespace Botan;
#include <iostream>
#include <memory>
int main(int argc, char* argv[])
   {
   if(argc != 5)
      {
      std::cout << "Usage: " << argv[0] << " <passphrase> "
                << "<ca cert> <ca key> <pkcs10>" << std::endl;
      return 1;
      }
try
      {
      const std::string arg_passphrase = argv[1];
      const std::string arg_ca_cert = argv[2];
      const std::string arg_ca_key = argv[3];
      const std::string arg_req_file = argv[4];
AutoSeeded_RNG rng;
X509_Certificate ca_cert(arg_ca_cert);
std::auto_ptr<PKCS8_PrivateKey> privkey(
         PKCS8::load_key(arg_ca_key, rng, arg_passphrase)
         );
X509_CA ca(ca_cert, *privkey);
// got a request
      PKCS10_Request req(arg_req_file);
// you would insert checks here, and perhaps modify the request
      // (this example should be extended to show how)
// now sign the request
      X509_Time start_time(system_time());
      X509_Time end_time(system_time() + 365 * 60 * 60 * 24);
X509_Certificate new_cert = ca.sign_request(req, rng,
                                                  start_time, end_time);
// send the new cert back to the requestor
      std::cout << new_cert.PEM_encode();
   }
   catch(std::exception& e)
      {
      std::cout << e.what() << std::endl;
      return 1;
      }
   return 0;
}
