If an engine comes up explicitely, it must also come down explicitely

In apps/apps.c, one can set up an engine with setup_engine().
However, we freed the structural reference immediately, which means
that for engines that don't already have a structural reference
somewhere else (because it's a built in engine), we end up returning
an invalid reference.

Instead, the function release_engine() is added, and called at the end
of the routines that call setup_engine().
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1643)

apps/apps.c

@@ -1280,14 +1280,20 @@ ENGINE *setup_engine(const char *engine, int debug)
         }
 
         BIO_printf(bio_err, "engine \"%s\" set.\n", ENGINE_get_id(e));
-
-        /* Free our "structural" reference. */
-        ENGINE_free(e);
     }
     return e;
 }
 #endif
 
+void release_engine(ENGINE *e)
+{
+#ifndef OPENSSL_NO_ENGINE
+    if (e != NULL)
+        /* Free our "structural" reference. */
+        ENGINE_free(e);
+#endif
+}
+
 static unsigned long index_serial_hash(const OPENSSL_CSTRING *a)
 {
     const char *n;

apps/apps.h

@@ -435,6 +435,7 @@ __owur int ctx_set_ctlog_list_file(SSL_CTX *ctx, const char *path);
 # else
 ENGINE *setup_engine(const char *engine, int debug);
 # endif
+void release_engine(ENGINE *e);
 # ifndef OPENSSL_NO_OCSP
 OCSP_RESPONSE *process_responder(OCSP_REQUEST *req,
                                  const char *host, const char *path,

apps/ca.c

@@ -1231,6 +1231,7 @@ end_of_options:
     X509_CRL_free(crl);
     NCONF_free(conf);
     NCONF_free(extconf);
+    release_engine(e);
     return (ret);
 }
 

apps/cms.c

@@ -1109,6 +1109,7 @@ int cms_main(int argc, char **argv)
     EVP_PKEY_free(key);
     CMS_ContentInfo_free(cms);
     CMS_ContentInfo_free(rcms);
+    release_engine(e);
     BIO_free(rctin);
     BIO_free(in);
     BIO_free(indata);

apps/dgst.c

@@ -398,6 +398,7 @@ int dgst_main(int argc, char **argv)
     sk_OPENSSL_STRING_free(macopts);
     OPENSSL_free(sigbuf);
     BIO_free(bmd);
+    release_engine(e);
     return (ret);
 }
 

apps/dhparam.c

@@ -70,6 +70,7 @@ int dhparam_main(int argc, char **argv)
     BIO *in = NULL, *out = NULL;
     DH *dh = NULL;
     char *infile = NULL, *outfile = NULL, *prog, *inrand = NULL;
+    ENGINE *e = NULL;
 #ifndef OPENSSL_NO_DSA
     int dsaparam = 0;
 #endif
@@ -104,7 +105,7 @@ int dhparam_main(int argc, char **argv)
             outfile = opt_arg();
             break;
         case OPT_ENGINE:
-            (void)setup_engine(opt_arg(), 0);
+            e = setup_engine(opt_arg(), 0);
             break;
         case OPT_CHECK:
             check = 1;
@@ -356,6 +357,7 @@ int dhparam_main(int argc, char **argv)
     BIO_free(in);
     BIO_free_all(out);
     DH_free(dh);
+    release_engine(e);
     return (ret);
 }
 

apps/dsa.c

@@ -249,6 +249,7 @@ int dsa_main(int argc, char **argv)
  end:
     BIO_free_all(out);
     DSA_free(dsa);
+    release_engine(e);
     OPENSSL_free(passin);
     OPENSSL_free(passout);
     return (ret);

apps/dsaparam.c

@@ -66,6 +66,7 @@ const OPTIONS dsaparam_options[] = {
 
 int dsaparam_main(int argc, char **argv)
 {
+    ENGINE *e = NULL;
     DSA *dsa = NULL;
     BIO *in = NULL, *out = NULL;
     BN_GENCB *cb = NULL;
@@ -105,7 +106,7 @@ int dsaparam_main(int argc, char **argv)
             outfile = opt_arg();
             break;
         case OPT_ENGINE:
-            (void)setup_engine(opt_arg(), 0);
+            e = setup_engine(opt_arg(), 0);
             break;
         case OPT_TIMEBOMB:
 # ifdef GENCB_TEST
@@ -285,6 +286,7 @@ int dsaparam_main(int argc, char **argv)
     BIO_free(in);
     BIO_free_all(out);
     DSA_free(dsa);
+    release_engine(e);
     return (ret);
 }
 

apps/ec.c

@@ -273,6 +273,7 @@ int ec_main(int argc, char **argv)
     BIO_free(in);
     BIO_free_all(out);
     EC_KEY_free(eckey);
+    release_engine(e);
     OPENSSL_free(passin);
     OPENSSL_free(passout);
     return (ret);

apps/ecparam.c

@@ -87,6 +87,7 @@ static OPT_PAIR encodings[] = {
 
 int ecparam_main(int argc, char **argv)
 {
+    ENGINE *e = NULL;
     BIGNUM *ec_gen = NULL, *ec_order = NULL, *ec_cofactor = NULL;
     BIGNUM *ec_p = NULL, *ec_a = NULL, *ec_b = NULL;
     BIO *in = NULL, *out = NULL;
@@ -168,7 +169,7 @@ int ecparam_main(int argc, char **argv)
             need_rand = 1;
             break;
         case OPT_ENGINE:
-            (void)setup_engine(opt_arg(), 0);
+            e = setup_engine(opt_arg(), 0);
             break;
         }
     }
@@ -454,9 +455,10 @@ int ecparam_main(int argc, char **argv)
     BN_free(ec_order);
     BN_free(ec_cofactor);
     OPENSSL_free(buffer);
+    EC_GROUP_free(group);
+    release_engine(e);
     BIO_free(in);
     BIO_free_all(out);
-    EC_GROUP_free(group);
     return (ret);
 }
 

apps/enc.c

@@ -82,6 +82,7 @@ int enc_main(int argc, char **argv)
 {
     static char buf[128];
     static const char magic[] = "Salted__";
+    ENGINE *e = NULL;
     BIO *in = NULL, *out = NULL, *b64 = NULL, *benc = NULL, *rbio =
         NULL, *wbio = NULL;
     EVP_CIPHER_CTX *ctx = NULL;
@@ -151,7 +152,7 @@ int enc_main(int argc, char **argv)
             passarg = opt_arg();
             break;
         case OPT_ENGINE:
-            (void)setup_engine(opt_arg(), 0);
+            e = setup_engine(opt_arg(), 0);
             break;
         case OPT_D:
             enc = 0;
@@ -552,6 +553,7 @@ int enc_main(int argc, char **argv)
 #ifdef ZLIB
     BIO_free(bzl);
 #endif
+    release_engine(e);
     OPENSSL_free(pass);
     return (ret);
 }

apps/gendsa.c

@@ -46,6 +46,7 @@ const OPTIONS gendsa_options[] = {
 
 int gendsa_main(int argc, char **argv)
 {
+    ENGINE *e = NULL;
     BIO *out = NULL, *in = NULL;
     DSA *dsa = NULL;
     const EVP_CIPHER *enc = NULL;
@@ -74,7 +75,7 @@ int gendsa_main(int argc, char **argv)
             passoutarg = opt_arg();
             break;
         case OPT_ENGINE:
-            (void)setup_engine(opt_arg(), 0);
+            e = setup_engine(opt_arg(), 0);
             break;
         case OPT_RAND:
             inrand = opt_arg();
@@ -139,6 +140,7 @@ int gendsa_main(int argc, char **argv)
     BIO_free(in);
     BIO_free_all(out);
     DSA_free(dsa);
+    release_engine(e);
     OPENSSL_free(passout);
     return (ret);
 }

apps/genpkey.c

@@ -193,8 +193,8 @@ int genpkey_main(int argc, char **argv)
     EVP_PKEY_CTX_free(ctx);
     BIO_free_all(out);
     BIO_free(in);
+    release_engine(e);
     OPENSSL_free(pass);
-
     return ret;
 }
 

apps/genrsa.c

@@ -166,6 +166,7 @@ int genrsa_main(int argc, char **argv)
     BN_GENCB_free(cb);
     RSA_free(rsa);
     BIO_free_all(out);
+    release_engine(eng);
     OPENSSL_free(passout);
     if (ret != 0)
         ERR_print_errors(bio_err);

apps/pkcs12.c

@@ -574,6 +574,7 @@ int pkcs12_main(int argc, char **argv)
     PKCS12_free(p12);
     if (export_cert || inrand)
         app_RAND_write_file(NULL);
+    release_engine(e);
     BIO_free(in);
     BIO_free_all(out);
     sk_OPENSSL_STRING_free(canames);

apps/pkcs7.c

@@ -44,6 +44,7 @@ const OPTIONS pkcs7_options[] = {
 
 int pkcs7_main(int argc, char **argv)
 {
+    ENGINE *e = NULL;
     PKCS7 *p7 = NULL;
     BIO *in = NULL, *out = NULL;
     int informat = FORMAT_PEM, outformat = FORMAT_PEM;
@@ -90,7 +91,7 @@ int pkcs7_main(int argc, char **argv)
             print_certs = 1;
             break;
         case OPT_ENGINE:
-            (void)setup_engine(opt_arg(), 0);
+            e = setup_engine(opt_arg(), 0);
             break;
         }
     }
@@ -189,6 +190,7 @@ int pkcs7_main(int argc, char **argv)
     ret = 0;
  end:
     PKCS7_free(p7);
+    release_engine(e);
     BIO_free(in);
     BIO_free_all(out);
     return (ret);

apps/pkcs8.c

@@ -343,6 +343,7 @@ int pkcs8_main(int argc, char **argv)
     X509_SIG_free(p8);
     PKCS8_PRIV_KEY_INFO_free(p8inf);
     EVP_PKEY_free(pkey);
+    release_engine(e);
     BIO_free_all(out);
     BIO_free(in);
     OPENSSL_free(passin);

apps/pkey.c

@@ -180,6 +180,7 @@ int pkey_main(int argc, char **argv)
 
  end:
     EVP_PKEY_free(pkey);
+    release_engine(e);
     BIO_free_all(out);
     BIO_free(in);
     OPENSSL_free(passin);

apps/pkeyparam.c

@@ -33,6 +33,7 @@ const OPTIONS pkeyparam_options[] = {
 
 int pkeyparam_main(int argc, char **argv)
 {
+    ENGINE *e = NULL;
     BIO *in = NULL, *out = NULL;
     EVP_PKEY *pkey = NULL;
     int text = 0, noout = 0, ret = 1;
@@ -58,7 +59,7 @@ int pkeyparam_main(int argc, char **argv)
             outfile = opt_arg();
             break;
         case OPT_ENGINE:
-            (void)setup_engine(opt_arg(), 0);
+            e = setup_engine(opt_arg(), 0);
             break;
         case OPT_TEXT:
             text = 1;
@@ -95,6 +96,7 @@ int pkeyparam_main(int argc, char **argv)
 
  end:
     EVP_PKEY_free(pkey);
+    release_engine(e);
     BIO_free_all(out);
     BIO_free(in);
 

apps/pkeyutl.c

@@ -323,6 +323,7 @@ int pkeyutl_main(int argc, char **argv)
 
  end:
     EVP_PKEY_CTX_free(ctx);
+    release_engine(e);
     BIO_free(in);
     BIO_free_all(out);
     OPENSSL_free(buf_in);

apps/rand.c

@@ -39,6 +39,7 @@ const OPTIONS rand_options[] = {
 
 int rand_main(int argc, char **argv)
 {
+    ENGINE *e = NULL;
     BIO *out = NULL;
     char *inrand = NULL, *outfile = NULL, *prog;
     OPTION_CHOICE o;
@@ -60,7 +61,7 @@ int rand_main(int argc, char **argv)
             outfile = opt_arg();
             break;
         case OPT_ENGINE:
-            (void)setup_engine(opt_arg(), 0);
+            e = setup_engine(opt_arg(), 0);
             break;
         case OPT_RAND:
             inrand = opt_arg();
@@ -125,6 +126,7 @@ int rand_main(int argc, char **argv)
  end:
     if (ret != 0)
         ERR_print_errors(bio_err);
+    release_engine(e);
     BIO_free_all(out);
     return (ret);
 }

apps/req.c

@@ -820,6 +820,7 @@ int req_main(int argc, char **argv)
     X509_REQ_free(req);
     X509_free(x509ss);
     ASN1_INTEGER_free(serial);
+    release_engine(e);
     if (passin != nofree_passin)
         OPENSSL_free(passin);
     if (passout != nofree_passout)

apps/rsa.c

@@ -294,6 +294,7 @@ int rsa_main(int argc, char **argv)
     } else
         ret = 0;
  end:
+    release_engine(e);
     BIO_free_all(out);
     RSA_free(rsa);
     OPENSSL_free(passin);

apps/rsautl.c

@@ -267,6 +267,7 @@ int rsautl_main(int argc, char **argv)
         BIO_write(out, rsa_out, rsa_outlen);
  end:
     RSA_free(rsa);
+    release_engine(e);
     BIO_free(in);
     BIO_free_all(out);
     OPENSSL_free(rsa_in);

apps/s_client.c

@@ -2506,6 +2506,7 @@ int s_client_main(int argc, char **argv)
     OPENSSL_clear_free(cbuf, BUFSIZZ);
     OPENSSL_clear_free(sbuf, BUFSIZZ);
     OPENSSL_clear_free(mbuf, BUFSIZZ);
+    release_engine(e);
     BIO_free(bio_c_out);
     bio_c_out = NULL;
     BIO_free(bio_c_msg);

apps/s_server.c

@@ -1963,6 +1963,7 @@ int s_server_main(int argc, char *argv[])
     ssl_excert_free(exc);
     sk_OPENSSL_STRING_free(ssl_args);
     SSL_CONF_CTX_free(cctx);
+    release_engine(engine);
     BIO_free(bio_s_out);
     bio_s_out = NULL;
     BIO_free(bio_s_msg);

apps/smime.c

@@ -614,6 +614,7 @@ int smime_main(int argc, char **argv)
     X509_free(signer);
     EVP_PKEY_free(key);
     PKCS7_free(p7);
+    release_engine(e);
     BIO_free(in);
     BIO_free(indata);
     BIO_free_all(out);

apps/speed.c

@@ -1219,6 +1219,7 @@ static int run_benchmark(int async_jobs,
 
 int speed_main(int argc, char **argv)
 {
+    ENGINE *e = NULL;
     loopargs_t *loopargs = NULL;
     int async_init = 0;
     int loopargs_len = 0;
@@ -1566,7 +1567,7 @@ int speed_main(int argc, char **argv)
 #endif
 
     /* Initialize the engine after the fork */
-    (void)setup_engine(engine_id, 0);
+    e = setup_engine(engine_id, 0);
 
     /* No parameters; turn on everything. */
     if ((argc == 0) && !doit[D_EVP]) {
@@ -2819,6 +2820,7 @@ int speed_main(int argc, char **argv)
         ASYNC_cleanup_thread();
     }
     OPENSSL_free(loopargs);
+    release_engine(e);
     return (ret);
 }
 

apps/spkac.c

@@ -187,6 +187,7 @@ int spkac_main(int argc, char **argv)
     NETSCAPE_SPKI_free(spki);
     BIO_free_all(out);
     EVP_PKEY_free(pkey);
+    release_engine(e);
     OPENSSL_free(passin);
     return (ret);
 }

apps/srp.c

@@ -209,6 +209,7 @@ const OPTIONS srp_options[] = {
 
 int srp_main(int argc, char **argv)
 {
+    ENGINE *e = NULL;
     CA_DB *db = NULL;
     CONF *conf = NULL;
     int gNindex = -1, maxgN = -1, ret = 1, errors = 0, verbose = 0, i;
@@ -269,7 +270,7 @@ int srp_main(int argc, char **argv)
             passoutarg = opt_arg();
             break;
         case OPT_ENGINE:
-            (void)setup_engine(opt_arg(), 0);
+            e = setup_engine(opt_arg(), 0);
             break;
         }
     }
@@ -602,6 +603,7 @@ int srp_main(int argc, char **argv)
         app_RAND_write_file(randfile);
     NCONF_free(conf);
     free_index(db);
+    release_engine(e);
     return (ret);
 }
 #endif

apps/verify.c

@@ -60,6 +60,7 @@ const OPTIONS verify_options[] = {
 
 int verify_main(int argc, char **argv)
 {
+    ENGINE *e = NULL;
     STACK_OF(X509) *untrusted = NULL, *trusted = NULL;
     STACK_OF(X509_CRL) *crls = NULL;
     X509_STORE *store = NULL;
@@ -140,7 +141,7 @@ int verify_main(int argc, char **argv)
             crl_download = 1;
             break;
         case OPT_ENGINE:
-            if (setup_engine(opt_arg(), 0) == NULL) {
+            if ((e = setup_engine(opt_arg(), 0)) == NULL) {
                 /* Failure message already displayed */
                 goto end;
             }
@@ -191,6 +192,7 @@ int verify_main(int argc, char **argv)
     sk_X509_pop_free(untrusted, X509_free);
     sk_X509_pop_free(trusted, X509_free);
     sk_X509_CRL_pop_free(crls, X509_CRL_free);
+    release_engine(e);
     return (ret < 0 ? 2 : ret);
 }
 

apps/x509.c

@@ -893,6 +893,7 @@ int x509_main(int argc, char **argv)
     sk_ASN1_OBJECT_pop_free(trust, ASN1_OBJECT_free);
     sk_ASN1_OBJECT_pop_free(reject, ASN1_OBJECT_free);
     ASN1_OBJECT_free(objtmp);
+    release_engine(e);
     OPENSSL_free(passin);
     return (ret);
 }