Remove ciphersuite from SSL session if single suite hardcoded
If MBEDTLS_SSL_SINGLE_CIPHERSUITE is enabled, the type
mbedtls_ssl_ciphersuite_handle_t
is logically a boolean (concretely realized as `unsigned char`),
containing the invalid handle and the unique valid handle, which
represents the single enabled ciphersuite.
The SSL session structure mbedtls_ssl_session contains an instance
of mbedtls_ssl_ciphersuite_handle_t which is guaranteed to be valid,
and which is hence redundant in any two-valued implementation of
mbedtls_ssl_ciphersuite_handle_t.
This commit replaces read-uses of
mbedtls_ssl_session::ciphersuite_info
by a getter functions which, and defines this getter function
either by just reading the field from the session structure
(in case MBEDTLS_SSL_SINGLE_CIPHERSUITE is disabled), or by
returning the single valid ciphersuite handle (in case
MBEDTLS_SSL_SINGLE_CIPHERSUITE is enabled) and removing the
field from mbedtls_ssl_session in this case.
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index f9b9502..daa9d74 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -923,7 +923,9 @@
#if defined(MBEDTLS_HAVE_TIME)
mbedtls_time_t start; /*!< starting time */
#endif
+#if !defined(MBEDTLS_SSL_SINGLE_CIPHERSUITE)
int ciphersuite; /*!< chosen ciphersuite */
+#endif /* MBEDTLS_SSL_SINGLE_CIPHERSUITE */
int compression; /*!< chosen compression */
size_t id_len; /*!< session id length */
unsigned char id[32]; /*!< session identifier */