Use hash_info_get_size in ssl_tls12_client

This way the code does not rely on the MBEDTLS_MD_C define
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/library/ssl_tls12_client.c b/library/ssl_tls12_client.c
index 01a0aec..f814094 100644
--- a/library/ssl_tls12_client.c
+++ b/library/ssl_tls12_client.c
@@ -53,6 +53,8 @@
 #include "mbedtls/platform_util.h"
 #endif
 
+#include "hash_info.h"
+
 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
 int mbedtls_ssl_conf_has_static_psk( mbedtls_ssl_config const *conf )
 {
@@ -2453,14 +2455,13 @@
 #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
         if( pk_alg == MBEDTLS_PK_RSASSA_PSS )
         {
-            const mbedtls_md_info_t* md_info;
             mbedtls_pk_rsassa_pss_options rsassa_pss_options;
             rsassa_pss_options.mgf1_hash_id = md_alg;
-            if( ( md_info = mbedtls_md_info_from_type( md_alg ) ) == NULL )
-            {
+            rsassa_pss_options.expected_salt_len =
+                                    mbedtls_hash_info_get_size( md_alg );
+            if( rsassa_pss_options.expected_salt_len == 0 )
                 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
-            }
-            rsassa_pss_options.expected_salt_len = mbedtls_md_get_size( md_info );
+
             ret = mbedtls_pk_verify_ext( pk_alg, &rsassa_pss_options,
                                          peer_pk,
                                          md_alg, hash, hashlen,