key.c

gistfile1.c

/*
example of c equivalent to php
<?php
// Create the keypair
$res=openssl_pkey_new();

// Get private key
openssl_pkey_export($res, $privkey);

// Get public key
$pubkey=openssl_pkey_get_details($res);
$pubkey=$pubkey["key"];
?>
*/
#include<stdio.h>
#include<openssl/rsa.h>
#include<openssl/evp.h>

EVP_PKEY *pubkey_a,*privkey_a;

generate_keys ()
{
  RSA *rsa, *pub_rsa, *priv_rsa;
  int len;
  unsigned char *buf, *p;

  rsa = RSA_generate_key (1024, RSA_F4, NULL, (char *) stdout);

  buf = (char *) malloc (2048);

  p = buf;

  len = i2d_RSAPublicKey (rsa, &p);
  len += i2d_RSAPrivateKey (rsa, &p);

  RSA_free (rsa);

  p = buf;
  pub_rsa = d2i_RSAPublicKey (NULL, &p, (long) len);
  len -= (p - buf);
  priv_rsa = d2i_RSAPrivateKey (NULL, &p, (long) len);

  if ((pub_rsa == NULL) || (priv_rsa == NULL))
    ERR_print_errors_fp (stderr);


  pubkey_a = EVP_PKEY_new ();
  privkey_a = EVP_PKEY_new ();

  EVP_PKEY_set1_RSA (pubkey_a, pub_rsa);
  EVP_PKEY_set1_RSA (privkey_a, priv_rsa);

  RSA_free (pub_rsa);
  RSA_free (priv_rsa);

}

main()
{   

  EVP_PKEY *pubkey,*privkey;

  generate_keys ();

  pubkey=pubkey_a;
  privkey=privkey_a;

  PEM_write_PUBKEY(stdout, pubkey);
  return 0;
 
}