+
+static int parse_ext_names(char *names, const char **result)
+{
+ char *p, *q;
+ int cnt = 0, len = 0;
+
+ p = q = names;
+ len = strlen(names);
+
+ while (q - names <= len) {
+ if (*q != ',' && *q != '\0') {
+ q++;
+ continue;
+ }
+ if (p != q) {
+ /* found */
+ if (result != NULL) {
+ result[cnt] = p;
+ *q = '\0';
+ }
+ cnt++;
+ }
+ p = ++q;
+ }
+
+ return cnt;
+}
+
+static int print_x509v3_exts(BIO *bio, X509 *x, const char *ext_names)
+{
+ const STACK_OF(X509_EXTENSION) *exts = NULL;
+ STACK_OF(X509_EXTENSION) *exts2 = NULL;
+ X509_EXTENSION *ext = NULL;
+ ASN1_OBJECT *obj;
+ int i, j, ret = 0, num, nn = 0;
+ const char *sn, **names = NULL;
+ char *tmp_ext_names = NULL;
+
+ exts = X509_get0_extensions(x);
+ if ((num = sk_X509_EXTENSION_num(exts)) <= 0) {
+ BIO_printf(bio, "No extensions in certificate\n");
+ ret = 1;
+ goto end;
+ }
+
+ /* parse comma separated ext name string */
+ if ((tmp_ext_names = OPENSSL_strdup(ext_names)) == NULL)
+ goto end;
+ if ((nn = parse_ext_names(tmp_ext_names, NULL)) == 0) {
+ BIO_printf(bio, "Invalid extension names: %s\n", ext_names);
+ goto end;
+ }
+ if ((names = OPENSSL_malloc(sizeof(char *) * nn)) == NULL)
+ goto end;
+ parse_ext_names(tmp_ext_names, names);
+
+ for (i = 0; i < num; i++) {
+ ext = sk_X509_EXTENSION_value(exts, i);
+
+ /* check if this ext is what we want */
+ obj = X509_EXTENSION_get_object(ext);
+ sn = OBJ_nid2sn(OBJ_obj2nid(obj));
+ if (sn == NULL || strcmp(sn, "UNDEF") == 0)
+ continue;
+
+ for (j = 0; j < nn; j++) {
+ if (strcmp(sn, names[j]) == 0) {
+ /* push the extension into a new stack */
+ if (exts2 == NULL
+ && (exts2 = sk_X509_EXTENSION_new_null()) == NULL)
+ goto end;
+ if (!sk_X509_EXTENSION_push(exts2, ext))
+ goto end;
+ }
+ }
+ }
+
+ if (!sk_X509_EXTENSION_num(exts2)) {
+ BIO_printf(bio, "No extensions matched with %s\n", ext_names);
+ ret = 1;
+ goto end;
+ }
+
+ ret = X509V3_extensions_print(bio, NULL, exts2, 0, 0);
+ end:
+ sk_X509_EXTENSION_free(exts2);
+ OPENSSL_free(names);
+ OPENSSL_free(tmp_ext_names);
+ return ret;
+}