I'm currently trying to programmatically create public/private key pairs with the OpenSSL (version 1.1.1) library but I cannot compile my program because I'm getting the following errors:
pointer to incomplete class type "evp_pkey_st" is not allowed
identifier "CRYPTO_mem_leaks" is undefined
I know OpenSSL is installed and is being recognized because I have included various OpenSSL header files without issue. The only include giving me a problem is openssl/evp.h which VSCode is telling me cannot be found. Does anyone know how to fix these issues? Thanks.
/* Certificate creation. Demonstrates some certificate related
* operations.
*/
#include <stdio.h>
#include <stdlib.h>
#include <openssl/pem.h>
#include <openssl/conf.h>
#include <openssl/x509v3.h>
#include <openssl/evp.h>
#include <openssl/crypto.h>
#ifndef OPENSSL_NO_ENGINE
#include <openssl/engine.h>
#endif
int mkcert(X509 **x509p, EVP_PKEY **pkeyp, int bits, int serial, int days);
int add_ext(X509 *cert, int nid, char *value);
int main(int argc, char **argv) {
BIO *bio_err;
X509 *x509=NULL;
EVP_PKEY *pkey=NULL;
CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ON);
bio_err=BIO_new_fp(stderr, BIO_NOCLOSE);
mkcert(&x509,&pkey,512,0,365);
RSA_print_fp(stdout,pkey->pkey.rsa,0);
X509_print_fp(stdout,x509);
PEM_write_PrivateKey(stdout,pkey,NULL,NULL,0,NULL, NULL);
PEM_write_X509(stdout,x509);
X509_free(x509);
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 mkcert(X509 **x509p, EVP_PKEY **pkeyp, int bits, int serial, int days)
{
X509 *x;
EVP_PKEY *pk;
RSA *rsa;
X509_NAME *name=NULL;
if ((pkeyp == NULL) || (*pkeyp == NULL))
{
if ((pk=EVP_PKEY_new()) == NULL)
{
abort();
return(0);
}
}
else
pk= *pkeyp;
if ((x509p == NULL) || (*x509p == NULL))
{
if ((x=X509_new()) == NULL)
goto err;
}
else
x= *x509p;
rsa=RSA_generate_key(bits,RSA_F4,callback,NULL);
if (!EVP_PKEY_assign_RSA(pk,rsa))
{
abort();
goto err;
}
rsa=NULL;
X509_set_version(x,2);
ASN1_INTEGER_set(X509_get_serialNumber(x),serial);
X509_gmtime_adj(X509_get_notBefore(x),0);
X509_gmtime_adj(X509_get_notAfter(x),(long)60*60*24*days);
X509_set_pubkey(x,pk);
name=X509_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);
/* Its self signed so set the issuer name to be the same as the
* subject.
*/
X509_set_issuer_name(x,name);
/* Add various extensions: standard extensions */
add_ext(x, NID_basic_constraints, "critical,CA:TRUE");
add_ext(x, NID_key_usage, "critical,keyCertSign,cRLSign");
add_ext(x, NID_subject_key_identifier, "hash");
/* Some Netscape specific extensions */
add_ext(x, NID_netscape_cert_type, "sslCA");
add_ext(x, NID_netscape_comment, "example comment extension");
#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
if (!X509_sign(x,pk,EVP_md5()))
goto err;
*x509p=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(X509 *cert, int nid, char *value)
{
X509_EXTENSION *ex;
X509V3_CTX ctx;
/* This sets the 'context' of the extensions. */
/* No configuration database */
X509V3_set_ctx_nodb(&ctx);
/* Issuer and subject certs: both the target since it is self signed,
* no request and no CRL
*/
X509V3_set_ctx(&ctx, cert, cert, NULL, NULL, 0);
ex = X509V3_EXT_conf_nid(NULL, &ctx, nid, value);
if (!ex)
return 0;
X509_add_ext(cert,ex,-1);
X509_EXTENSION_free(ex);
return 1;
}
In comments, you say you are compiling for OpenSSL 1.1.1.
Direct access to OpenSSL struct members, such as in pkey->pkey.rsa, is no longer possible in OpenSSL 1.1.x onward, as OpenSSL has moved away from using typed struct pointers and now uses opaque pointers instead. The reason is so that OpenSSL structs can now change layout between versions without breaking code, something that wasn't really possible before 1.1.0.
Per OpenSSL's wiki: OpenSSL 1.1.0 Changes
All structures in libssl public header files have been removed so that they are "opaque" to library users. You should use the provided accessor functions instead
As such, you now have to use individual getter/setter functions for each member. In this case, I think it is EVP_PKEY_get1_RSA(), eg:
RSA_print_fp(stdout,EVP_PKEY_get1_RSA(pkey),0);
As for CRYPTO_mem_leaks(), are you sure you are compiling for OpenSSL 1.1.1 and not 3.0? CRYPTO_mem_leaks() is deprecated in 3.0:
The following functions have been deprecated since OpenSSL 3.0, and can be hidden entirely by defining OPENSSL_API_COMPAT with a suitable version value, see openssl_user_macros(7):
int CRYPTO_mem_leaks(BIO *b); int CRYPTO_mem_leaks_fp(FILE *fp); int CRYPTO_mem_leaks_cb(int (*cb)(const char *str, size_t len, void *u), void *u); int CRYPTO_set_mem_debug(int onoff); int CRYPTO_mem_ctrl(int mode); int OPENSSL_mem_debug_push(const char *info); int OPENSSL_mem_debug_pop(void); int CRYPTO_mem_debug_push(const char *info, const char *file, int line); int CRYPTO_mem_debug_pop(void);