text: /* Certificate request creation. Demonstrates some request related
   * operations.
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  
  #include <openssl/pem.h>
  #include <openssl/conf.h>
  #include <openssl/x509v3.h>
  #ifndef OPENSSL_NO_ENGINE
  #include <openssl/engine.h>
  #endif
  
  int mkreq(X509_REQ **x509p, EVP_PKEY **pkeyp, int bits, int serial, int days);
  int add_ext(STACK_OF(X509_REQUEST) *sk, int nid, char *value);
  
  int main(int argc, char **argv)
  	{
  	BIO *bio_err;
  	X509_REQ *req=NULL;
  	EVP_PKEY *pkey=NULL;
  
  	CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ON);
  
  	bio_err=BIO_new_fp(stderr, BIO_NOCLOSE);
  
  	mkreq(&req,&pkey,512,0,365);
  
  	RSA_print_fp(stdout,pkey->pkey.rsa,0);
  	X509_REQ_print_fp(stdout,req);
  
  	PEM_write_X509_REQ(stdout,req);
  
  	X509_REQ_free(req);
  	EVP_PKEY_free(pkey);
  
  #ifndef OPENSSL_NO_ENGINE
  	ENGINE_cleanup();
  #endif
  	CRYPTO_cleanup_all_ex_data();
  
  	CRYPTO_mem_leaks(bio_err);
  	BIO_free(bio_err);
  	return(0);
  	}
  
  static void callback(int p, int n, void *arg)
  	{
  	char c='B';
  
  	if (p == 0) c='.';
  	if (p == 1) c='+';
  	if (p == 2) c='*';
  	if (p == 3) c='\n';
  	fputc(c,stderr);
  	}
  
  int mkreq(X509_REQ **req, EVP_PKEY **pkeyp, int bits, int serial, int days)
  	{
  	X509_REQ *x;
  	EVP_PKEY *pk;
  	RSA *rsa;
  	X509_NAME *name=NULL;
  	STACK_OF(X509_EXTENSION) *exts = NULL;
  	
  	if ((pk=EVP_PKEY_new()) == NULL)
  		goto err;
  
  	if ((x=X509_REQ_new()) == NULL)
  		goto err;
  
  	rsa=RSA_generate_key(bits,RSA_F4,callback,NULL);
  	if (!EVP_PKEY_assign_RSA(pk,rsa))
  		goto err;
  
  	rsa=NULL;
  
  	X509_REQ_set_pubkey(x,pk);
  
  	name=X509_REQ_get_subject_name(x);
  
  	/* This function creates and adds the entry, working out the
  	 * correct string type and performing checks on its length.
  	 * Normally we'd check the return value for errors...
  	 */
  	X509_NAME_add_entry_by_txt(name,"C",
  				MBSTRING_ASC, "UK", -1, -1, 0);
  	X509_NAME_add_entry_by_txt(name,"CN",
  				MBSTRING_ASC, "OpenSSL Group", -1, -1, 0);
  
  #ifdef REQUEST_EXTENSIONS
  	/* Certificate requests can contain extensions, which can be used
  	 * to indicate the extensions the requestor would like added to 
  	 * their certificate. CAs might ignore them however or even choke
  	 * if they are present.
  	 */
  
  	/* For request extensions they are all packed in a single attribute.
  	 * We save them in a STACK and add them all at once later...
  	 */
  
  	exts = sk_X509_EXTENSION_new_null();
  	/* Standard extenions */
  
  	add_ext(exts, NID_key_usage, "critical,digitalSignature,keyEncipherment");
  
  	/* This is a typical use for request extensions: requesting a value for
  	 * subject alternative name.
  	 */
  
  	add_ext(exts, NID_subject_alt_name, "email:steve@openssl.org");
  
  	/* Some Netscape specific extensions */
  	add_ext(exts, NID_netscape_cert_type, "client,email");
  
  
  
  #ifdef CUSTOM_EXT
  	/* Maybe even add our own extension based on existing */
  	{
  		int nid;
  		nid = OBJ_create("1.2.3.4", "MyAlias", "My Test Alias Extension");
  		X509V3_EXT_add_alias(nid, NID_netscape_comment);
  		add_ext(x, nid, "example comment alias");
  	}
  #endif
  
  	/* Now we've created the extensions we add them to the request */
  
  	X509_REQ_add_extensions(x, exts);
  
  	sk_X509_EXTENSION_pop_free(exts, X509_EXTENSION_free);
  
  #endif
  	
  	if (!X509_REQ_sign(x,pk,EVP_sha1()))
  		goto err;
  
  	*req=x;
  	*pkeyp=pk;
  	return(1);
  err:
  	return(0);
  	}
  
  /* Add extension using V3 code: we can set the config file as NULL
   * because we wont reference any other sections.
   */
  
  int add_ext(STACK_OF(X509_REQUEST) *sk, int nid, char *value)
  	{
  	X509_EXTENSION *ex;
  	ex = X509V3_EXT_conf_nid(NULL, NULL, nid, value);
  	if (!ex)
  		return 0;
  	sk_X509_EXTENSION_push(sk, ex);
  
  	return 1;
  	}
  	
  