Fix empty union when TLS is disabled
When all TLS 1.2 support is disabled, union mbedtls_ssl_premaster_secret was
empty, which is not valid C even if the union is never used. Fixes #6628.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/ChangeLog.d/ssl_premaster_secret-empty.txt b/ChangeLog.d/ssl_premaster_secret-empty.txt
new file mode 100644
index 0000000..0ce5f36
--- /dev/null
+++ b/ChangeLog.d/ssl_premaster_secret-empty.txt
@@ -0,0 +1,3 @@
+Bugfix
+ * Fix a compilation error on some platforms when including mbedtls/ssl.h
+ with all TLS support disabled. Fixes #6628.
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 68e8d04..006b255 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -620,6 +620,7 @@
/* Dummy type used only for its size */
union mbedtls_ssl_premaster_secret {
+ unsigned char dummy; /* Make the union non-empty even with SSL disabled */
#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
unsigned char _pms_rsa[48]; /* RFC 5246 8.1.1 */
#endif