SSL test programs: stuff RNG context into a struct

Group the random generation context (entropy and DRBG) into a struct.
This is in preparation for unifying the common RNG-related code of
ssl_client2 and ssl_server2, then generalizing that code to support
methods other than entropy+CTR_DRBG.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>

programs/ssl/ssl_client2.c

@@ -686,8 +686,7 @@ int main( int argc, char *argv[] )
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
     mbedtls_x509_crt_profile crt_profile_for_test = mbedtls_x509_crt_profile_default;
 #endif
-    mbedtls_entropy_context entropy;
-    mbedtls_ctr_drbg_context ctr_drbg;
+    rng_context_t rng;
     mbedtls_ssl_context ssl;
     mbedtls_ssl_config conf;
     mbedtls_ssl_session saved_session;
@@ -742,7 +741,7 @@ int main( int argc, char *argv[] )
     mbedtls_ssl_init( &ssl );
     mbedtls_ssl_config_init( &conf );
     memset( &saved_session, 0, sizeof( mbedtls_ssl_session ) );
-    mbedtls_ctr_drbg_init( &ctr_drbg );
+    mbedtls_ctr_drbg_init( &rng.drbg );
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
     mbedtls_x509_crt_init( &cacert );
     mbedtls_x509_crt_init( &clicert );
@@ -1534,12 +1533,12 @@ int main( int argc, char *argv[] )
     mbedtls_printf( "\n  . Seeding the random number generator..." );
     fflush( stdout );
 
-    mbedtls_entropy_init( &entropy );
+    mbedtls_entropy_init( &rng.entropy );
     if (opt.reproducible)
     {
         srand( 1 );
-        if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, dummy_entropy,
-                                           &entropy, (const unsigned char *) pers,
+        if( ( ret = mbedtls_ctr_drbg_seed( &rng.drbg, dummy_entropy,
+                                           &rng.entropy, (const unsigned char *) pers,
                                            strlen( pers ) ) ) != 0 )
         {
             mbedtls_printf( " failed\n  ! mbedtls_ctr_drbg_seed returned -0x%x\n",
@@ -1549,8 +1548,8 @@ int main( int argc, char *argv[] )
     }
     else
     {
-        if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func,
-                                           &entropy, (const unsigned char *) pers,
+        if( ( ret = mbedtls_ctr_drbg_seed( &rng.drbg, mbedtls_entropy_func,
+                                           &rng.entropy, (const unsigned char *) pers,
                                            strlen( pers ) ) ) != 0 )
         {
             mbedtls_printf( " failed\n  ! mbedtls_ctr_drbg_seed returned -0x%x\n",
@@ -1904,7 +1903,7 @@ int main( int argc, char *argv[] )
 #endif
 #endif
     }
-    mbedtls_ssl_conf_rng( &conf, mbedtls_ctr_drbg_random, &ctr_drbg );
+    mbedtls_ssl_conf_rng( &conf, mbedtls_ctr_drbg_random, &rng.drbg );
     mbedtls_ssl_conf_dbg( &conf, my_debug, stdout );
 
     mbedtls_ssl_conf_read_timeout( &conf, opt.read_timeout );
@@ -3024,8 +3023,8 @@ exit:
     mbedtls_ssl_session_free( &saved_session );
     mbedtls_ssl_free( &ssl );
     mbedtls_ssl_config_free( &conf );
-    mbedtls_ctr_drbg_free( &ctr_drbg );
-    mbedtls_entropy_free( &entropy );
+    mbedtls_ctr_drbg_free( &rng.drbg );
+    mbedtls_entropy_free( &rng.entropy );
     if( session_data != NULL )
         mbedtls_platform_zeroize( session_data, session_data_len );
     mbedtls_free( session_data );

programs/ssl/ssl_server2.c

@@ -1282,8 +1282,7 @@ int main( int argc, char *argv[] )
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
     mbedtls_x509_crt_profile crt_profile_for_test = mbedtls_x509_crt_profile_default;
 #endif
-    mbedtls_entropy_context entropy;
-    mbedtls_ctr_drbg_context ctr_drbg;
+    rng_context_t rng;
     mbedtls_ssl_context ssl;
     mbedtls_ssl_config conf;
 #if defined(MBEDTLS_TIMING_C)
@@ -1377,7 +1376,7 @@ int main( int argc, char *argv[] )
     mbedtls_net_init( &listen_fd );
     mbedtls_ssl_init( &ssl );
     mbedtls_ssl_config_init( &conf );
-    mbedtls_ctr_drbg_init( &ctr_drbg );
+    mbedtls_ctr_drbg_init( &rng.drbg );
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
     mbedtls_x509_crt_init( &cacert );
     mbedtls_x509_crt_init( &srvcert );
@@ -2293,12 +2292,12 @@ int main( int argc, char *argv[] )
     mbedtls_printf( "\n  . Seeding the random number generator..." );
     fflush( stdout );
 
-    mbedtls_entropy_init( &entropy );
+    mbedtls_entropy_init( &rng.entropy );
     if (opt.reproducible)
     {
         srand( 1 );
-        if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, dummy_entropy,
-                                           &entropy, (const unsigned char *) pers,
+        if( ( ret = mbedtls_ctr_drbg_seed( &rng.drbg, dummy_entropy,
+                                           &rng.entropy, (const unsigned char *) pers,
                                            strlen( pers ) ) ) != 0 )
         {
             mbedtls_printf( " failed\n  ! mbedtls_ctr_drbg_seed returned -0x%x\n",
@@ -2308,8 +2307,8 @@ int main( int argc, char *argv[] )
     }
     else
     {
-        if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func,
-                                           &entropy, (const unsigned char *) pers,
+        if( ( ret = mbedtls_ctr_drbg_seed( &rng.drbg, mbedtls_entropy_func,
+                                           &rng.entropy, (const unsigned char *) pers,
                                            strlen( pers ) ) ) != 0 )
         {
             mbedtls_printf( " failed\n  ! mbedtls_ctr_drbg_seed returned -0x%x\n",
@@ -2706,7 +2705,7 @@ int main( int argc, char *argv[] )
 #endif
 #endif
     }
-    mbedtls_ssl_conf_rng( &conf, mbedtls_ctr_drbg_random, &ctr_drbg );
+    mbedtls_ssl_conf_rng( &conf, mbedtls_ctr_drbg_random, &rng.drbg );
     mbedtls_ssl_conf_dbg( &conf, my_debug, stdout );
 
 #if defined(MBEDTLS_SSL_CACHE_C)
@@ -2725,7 +2724,7 @@ int main( int argc, char *argv[] )
     if( opt.tickets == MBEDTLS_SSL_SESSION_TICKETS_ENABLED )
     {
         if( ( ret = mbedtls_ssl_ticket_setup( &ticket_ctx,
-                        mbedtls_ctr_drbg_random, &ctr_drbg,
+                        mbedtls_ctr_drbg_random, &rng.drbg,
                         MBEDTLS_CIPHER_AES_256_GCM,
                         opt.ticket_timeout ) ) != 0 )
         {
@@ -2747,7 +2746,7 @@ int main( int argc, char *argv[] )
         if( opt.cookies > 0 )
         {
             if( ( ret = mbedtls_ssl_cookie_setup( &cookie_ctx,
-                                          mbedtls_ctr_drbg_random, &ctr_drbg ) ) != 0 )
+                                          mbedtls_ctr_drbg_random, &rng.drbg ) ) != 0 )
             {
                 mbedtls_printf( " failed\n  ! mbedtls_ssl_cookie_setup returned %d\n\n", ret );
                 goto exit;
@@ -2900,7 +2899,7 @@ int main( int argc, char *argv[] )
                                         - opt.async_private_error :
                                         opt.async_private_error );
         ssl_async_keys.f_rng = mbedtls_ctr_drbg_random;
-        ssl_async_keys.p_rng = &ctr_drbg;
+        ssl_async_keys.p_rng = &rng.drbg;
         mbedtls_ssl_conf_async_private_cb( &conf,
                                            sign,
                                            decrypt,
@@ -3998,8 +3997,8 @@ exit:
 
     mbedtls_ssl_free( &ssl );
     mbedtls_ssl_config_free( &conf );
-    mbedtls_ctr_drbg_free( &ctr_drbg );
-    mbedtls_entropy_free( &entropy );
+    mbedtls_ctr_drbg_free( &rng.drbg );
+    mbedtls_entropy_free( &rng.entropy );
 
 #if defined(MBEDTLS_SSL_CACHE_C)
     mbedtls_ssl_cache_free( &cache );

programs/ssl/ssl_test_lib.h

@@ -128,6 +128,14 @@ mbedtls_time_t dummy_constant_time( mbedtls_time_t* time );
 
 int dummy_entropy( void *data, unsigned char *output, size_t len );
 
+/** A context for random generation.
+ */
+typedef struct
+{
+    mbedtls_entropy_context entropy;
+    mbedtls_ctr_drbg_context drbg;
+} rng_context_t;
+
 #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
 int ca_callback( void *data, mbedtls_x509_crt const *child,
                  mbedtls_x509_crt **candidates );