// SPDX-License-Identifier: GPL-2.0-or-later /* mpihelp-sub.c - MPI helper functions * Copyright (C) 1994, 1996 Free Software Foundation, Inc. * Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc. * * This file is part of GnuPG. * * Note: This code is heavily based on the GNU MP Library. * Actually it's the same code with only minor changes in the * way the data is stored; this is to support the abstraction * of an optional secure memory allocation which may be used * to avoid revealing of sensitive data due to paging etc. * The GNU MP Library itself is published under the LGPL; * however I decided to publish this code under the plain GPL. */ #include "mpi-internal.h" /**************** * Compare OP1_PTR/OP1_SIZE with OP2_PTR/OP2_SIZE. * There are no restrictions on the relative sizes of * the two arguments. * Return 1 if OP1 > OP2, 0 if they are equal, and -1 if OP1 < OP2. */ int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size) { mpi_size_t i; mpi_limb_t op1_word, op2_word; for (i = size - 1; i >= 0; i--) { op1_word = op1_ptr[i]; op2_word = op2_ptr[i]; if (op1_word != op2_word) goto diff; } return 0; diff: /* This can *not* be simplified to * op2_word - op2_word * since that expression might give signed overflow. */ return (op1_word > op2_word) ? 1 : -1; }