Merge pull request #3720 from militant-daos/mbedtls-2.16
backport 2.16: Fix premature fopen() call in mbedtls_entropy_write_seed_file
diff --git a/ChangeLog.d/bugfix_PR3616.txt b/ChangeLog.d/bugfix_PR3616.txt
new file mode 100644
index 0000000..47d1044
--- /dev/null
+++ b/ChangeLog.d/bugfix_PR3616.txt
@@ -0,0 +1,5 @@
+Bugfix
+ * Fix premature fopen() call in mbedtls_entropy_write_seed_file which may
+ lead to the seed file corruption in case if the path to the seed file is
+ equal to MBEDTLS_PLATFORM_STD_NV_SEED_FILE. Contributed by Victor
+ Krasnoshchok in #3616.
diff --git a/library/entropy.c b/library/entropy.c
index c5f414a..9f1a32b 100644
--- a/library/entropy.c
+++ b/library/entropy.c
@@ -494,14 +494,20 @@
int mbedtls_entropy_write_seed_file( mbedtls_entropy_context *ctx, const char *path )
{
int ret = MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR;
- FILE *f;
+ FILE *f = NULL;
unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
- if( ( f = fopen( path, "wb" ) ) == NULL )
- return( MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR );
-
if( ( ret = mbedtls_entropy_func( ctx, buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) ) != 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 )
{
@@ -514,7 +520,9 @@
exit:
mbedtls_platform_zeroize( buf, sizeof( buf ) );
- fclose( 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 8ad8760..25fd57f 100644
--- a/tests/suites/test_suite_entropy.data
+++ b/tests/suites/test_suite_entropy.data
@@ -13,6 +13,9 @@
Entropy write/update seed file
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 too many sources
entropy_too_many_sources:
diff --git a/tests/suites/test_suite_entropy.function b/tests/suites/test_suite_entropy.function
index f4f9693..6aa8dd3 100644
--- a/tests/suites/test_suite_entropy.function
+++ b/tests/suites/test_suite_entropy.function
@@ -162,6 +162,21 @@
}
/* 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_too_many_sources( )
{