From b3129ba11930c81fb47b58d81e4c4651a24aaec6 Mon Sep 17 00:00:00 2001
From: Victor Krasnoshchok <ct3da21164@protonmail.ch>
Date: Sat, 29 Aug 2020 22:54:37 +0300
Subject: [PATCH] Refactoring after CR and new unit test #3175

Signed-off-by: Victor Krasnoshchok <ct3da21164@protonmail.ch>
---
 library/entropy.c                        | 25 +++++++++++++++---------
 tests/suites/test_suite_entropy.data     |  3 +++
 tests/suites/test_suite_entropy.function | 15 ++++++++++++++
 3 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/library/entropy.c b/library/entropy.c
index 519c3aef3..fd2c207f0 100644
--- a/library/entropy.c
+++ b/library/entropy.c
@@ -466,25 +466,32 @@ int mbedtls_entropy_update_nv_seed( mbedtls_entropy_context *ctx )
 #if defined(MBEDTLS_FS_IO)
 int mbedtls_entropy_write_seed_file( mbedtls_entropy_context *ctx, const char *path )
 {
-    int ret;
+    int ret = 0;
     FILE *f = NULL;
     unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
 
     if( ( ret = mbedtls_entropy_func( ctx, buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) ) != 0 )
-        goto exit;
-
-    ret = MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR;
-    if( ( f = fopen( path, "wb" ) ) != NULL )
     {
-        if( fwrite( buf, 1, MBEDTLS_ENTROPY_BLOCK_SIZE, f ) != MBEDTLS_ENTROPY_BLOCK_SIZE )
-            goto exit;
-        ret = 0;
+        ret = MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
+        goto exit;
+    }
+
+    if( ( f = fopen( path, "wb" ) ) == NULL )
+    {
+        ret = MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR;
+        goto exit;
+    }
+
+    if( fwrite( buf, 1, MBEDTLS_ENTROPY_BLOCK_SIZE, f ) != MBEDTLS_ENTROPY_BLOCK_SIZE )
+    {
+        ret = MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR;
+        goto exit;
     }
 
 exit:
     mbedtls_platform_zeroize( buf, sizeof( buf ) );
 
-    if( f )
+    if( f != NULL )
         fclose( f );
 
     return( ret );
diff --git a/tests/suites/test_suite_entropy.data b/tests/suites/test_suite_entropy.data
index b2d20b472..bc077f815 100644
--- a/tests/suites/test_suite_entropy.data
+++ b/tests/suites/test_suite_entropy.data
@@ -7,6 +7,9 @@ entropy_seed_file:"data_files/entropy_seed":0
 Entropy write/update seed file: nonexistent
 entropy_seed_file:"no_such_dir/file":MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR
 
+Entropy write/update seed file: base NV seed file
+entropy_write_base_seed_file:0
+
 Entropy no sources
 entropy_no_sources:
 
diff --git a/tests/suites/test_suite_entropy.function b/tests/suites/test_suite_entropy.function
index d9ea44149..a453aadf3 100644
--- a/tests/suites/test_suite_entropy.function
+++ b/tests/suites/test_suite_entropy.function
@@ -149,6 +149,21 @@ exit:
 }
 /* END_CASE */
 
+/* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_FS_IO */
+void entropy_write_base_seed_file( int ret )
+{
+    mbedtls_entropy_context ctx;
+
+    mbedtls_entropy_init( &ctx );
+
+    TEST_ASSERT( mbedtls_entropy_write_seed_file( &ctx, MBEDTLS_PLATFORM_STD_NV_SEED_FILE ) == ret );
+    TEST_ASSERT( mbedtls_entropy_update_seed_file( &ctx, MBEDTLS_PLATFORM_STD_NV_SEED_FILE ) == ret );
+
+exit:
+    mbedtls_entropy_free( &ctx );
+}
+/* END_CASE */
+
 /* BEGIN_CASE */
 void entropy_no_sources( )
 {