protect _gnutls_params_get_rsa_raw() from crashing when exporting an RSA public key

That could happen in case of PKCS #11 abstract keys.

diff --git a/lib/gnutls_pk.c b/lib/gnutls_pk.c
index 6601d3e2b341c3c7a1b70052ea1425602f3833e5..2b5ad3e0b4f6604abfb54e98b2c8291033054458 100644 (file)
--- a/lib/gnutls_pk.c
+++ b/lib/gnutls_pk.c
@@ -439,57 +439,75 @@ _gnutls_params_get_rsa_raw(const gnutls_pk_params_st* params,
        }
 
        /* D */
-       if (d) {
+       if (d && params->params[2]) {
                ret = _gnutls_mpi_dprint_lz(params->params[2], d);
                if (ret < 0) {
                        gnutls_assert();
                        goto error;
                }
+       } else if (d) {
+               d->data = NULL;
+               d->size = 0;
        }
 
        /* P */
-       if (p) {
+       if (p && params->params[3]) {
                ret = _gnutls_mpi_dprint_lz(params->params[3], p);
                if (ret < 0) {
                        gnutls_assert();
                        goto error;
                }
+       } else if (p) {
+               p->data = NULL;
+               p->size = 0;
        }
 
        /* Q */
-       if (q) {
+       if (q && params->params[4]) {
                ret = _gnutls_mpi_dprint_lz(params->params[4], q);
                if (ret < 0) {
                        gnutls_assert();
                        goto error;
                }
+       } else if (q) {
+               q->data = NULL;
+               q->size = 0;
        }
 
        /* U */
-       if (u) {
+       if (u && params->params[5]) {
                ret = _gnutls_mpi_dprint_lz(params->params[5], u);
                if (ret < 0) {
                        gnutls_assert();
                        goto error;
                }
+       } else if (u) {
+               u->data = NULL;
+               u->size = 0;
        }
 
        /* E1 */
-       if (e1) {
+       if (e1 && params->params[6]) {
                ret = _gnutls_mpi_dprint_lz(params->params[6], e1);
                if (ret < 0) {
                        gnutls_assert();
                        goto error;
                }
+       } else if (e1) {
+               e1->data = NULL;
+               e1->size = 0;
        }
 
        /* E2 */
-       if (e2) {
+       if (e2 && params->params[7]) {
                ret = _gnutls_mpi_dprint_lz(params->params[7], e2);
                if (ret < 0) {
                        gnutls_assert();
                        goto error;
                }
+       } else if (e2) {
+               e2->data = NULL;
+               e2->size = 0;
        }
 
        return 0;