dh_genprime: Fix issue where the error code returned by mbedtls_mpi_write_file() is incorrectly reported on failure
In 'dh_genprime.c', the following condition can be found inside an 'if' statement:
ret = mbedtls_mpi_write_file( "P = ", &P, 16, fout ) != 0
As the '!=' operator binds closer than the assignment operator ('='), the value assigned to 'ret' will be the boolean result of the comparison (0 or 1) instead of the status code returned by 'mbedtls_mpi_write_file'. This means that the above statement is actually equivalent to:
ret = ( mbedtls_mpi_write_file( "P = ", &P, 16, fout ) != 0 )
What we want instead is for the the status code to be assigned to 'ret'. If the value assigned is non-zero, it will be 'truthy' and the 'if' branch will be taken.
( ret = mbedtls_mpi_write_file( "P = ", &P, 16, fout ) ) != 0
This PR fixes the issue by explicitly specifying the precedence of operations with parentheses.
Signed-off-by: ihsinme <ihsinme@gmail.com>
diff --git a/programs/pkey/dh_genprime.c b/programs/pkey/dh_genprime.c
index 2e696e5..331838b 100644
--- a/programs/pkey/dh_genprime.c
+++ b/programs/pkey/dh_genprime.c
@@ -157,8 +157,8 @@
goto exit;
}
- if( ( ret = mbedtls_mpi_write_file( "P = ", &P, 16, fout ) != 0 ) ||
- ( ret = mbedtls_mpi_write_file( "G = ", &G, 16, fout ) != 0 ) )
+ if( ( ( ret = mbedtls_mpi_write_file( "P = ", &P, 16, fout ) ) != 0 ) ||
+ ( ( ret = mbedtls_mpi_write_file( "G = ", &G, 16, fout ) ) != 0 ) )
{
mbedtls_printf( " failed\n ! mbedtls_mpi_write_file returned %d\n\n", ret );
fclose( fout );