From: Ard Biesheuvel <ardb@kernel.org>
To: "Stephan Müller" <smueller@chronox.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>,
Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
Marcelo Cerri <marcelo.cerri@canonical.com>,
Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Subject: Re: [PATCH 2/3] lib/mpi: Add mpi_sub_ui()
Date: Fri, 10 Jul 2020 17:42:39 +0300 [thread overview]
Message-ID: <CAMj1kXFjzHphXUt7Hesj_EAOJmar9Du1U6YM9X+davMOB6tcng@mail.gmail.com> (raw)
In-Reply-To: <4577235.31r3eYUQgx@positron.chronox.de>
On Fri, 10 Jul 2020 at 13:16, Stephan Müller <smueller@chronox.de> wrote:
>
> Add mpi_sub_ui() based on Gnu PG mpz_sub_ui() from mpz/aors_ui.h
> adapting the code to the kernel's structures and coding style and also
> removing the defines used to produce mpz_sub_ui() and mpz_add_ui()
> from the same code.
>
Isn't GnuPG GPLv3 ?
> Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com>
> Signed-off-by: Stephan Mueller <smueller@chronox.de>
> ---
> include/linux/mpi.h | 3 +++
> lib/mpi/Makefile | 1 +
> lib/mpi/mpi-sub-ui.c | 60 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 64 insertions(+)
> create mode 100644 lib/mpi/mpi-sub-ui.c
>
> diff --git a/include/linux/mpi.h b/include/linux/mpi.h
> index 7bd6d8af0004..5d906dfbf3ed 100644
> --- a/include/linux/mpi.h
> +++ b/include/linux/mpi.h
> @@ -63,6 +63,9 @@ int mpi_powm(MPI res, MPI base, MPI exp, MPI mod);
> int mpi_cmp_ui(MPI u, ulong v);
> int mpi_cmp(MPI u, MPI v);
>
> +/*-- mpi-sub-ui.c --*/
> +int mpi_sub_ui(MPI w, MPI u, unsigned long vval);
> +
> /*-- mpi-bit.c --*/
> void mpi_normalize(MPI a);
> unsigned mpi_get_nbits(MPI a);
> diff --git a/lib/mpi/Makefile b/lib/mpi/Makefile
> index d5874a7f5ff9..43b8fce14079 100644
> --- a/lib/mpi/Makefile
> +++ b/lib/mpi/Makefile
> @@ -16,6 +16,7 @@ mpi-y = \
> mpicoder.o \
> mpi-bit.o \
> mpi-cmp.o \
> + mpi-sub-ui.o \
> mpih-cmp.o \
> mpih-div.o \
> mpih-mul.o \
> diff --git a/lib/mpi/mpi-sub-ui.c b/lib/mpi/mpi-sub-ui.c
> new file mode 100644
> index 000000000000..fa6b085bac36
> --- /dev/null
> +++ b/lib/mpi/mpi-sub-ui.c
> @@ -0,0 +1,60 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/* mpi-sub-ui.c - MPI functions
> + * Copyright 1991, 1993, 1994, 1996, 1999-2002, 2004, 2012, 2013, 2015
> + * 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"
> +
> +int mpi_sub_ui(MPI w, MPI u, unsigned long vval)
> +{
> + if (u->nlimbs == 0) {
> + if (mpi_resize(w, 1) < 0)
> + return -ENOMEM;
> + w->d[0] = vval;
> + w->nlimbs = (vval != 0);
> + w->sign = (vval != 0);
> + return 0;
> + }
> +
> + /* If not space for W (and possible carry), increase space. */
> + if (mpi_resize(w, u->nlimbs + 1))
> + return -ENOMEM;
> +
> + if (u->sign) {
> + mpi_limb_t cy;
> +
> + cy = mpihelp_add_1(w->d, u->d, u->nlimbs, (mpi_limb_t) vval);
> + w->d[u->nlimbs] = cy;
> + w->nlimbs = u->nlimbs + cy;
> + w->sign = 1;
> + } else {
> + /* The signs are different. Need exact comparison to determine
> + * which operand to subtract from which.
> + */
> + if (u->nlimbs == 1 && u->d[0] < vval) {
> + w->d[0] = vval - u->d[0];
> + w->nlimbs = 1;
> + w->sign = 1;
> + } else {
> + mpihelp_sub_1(w->d, u->d, u->nlimbs, (mpi_limb_t) vval);
> + /* Size can decrease with at most one limb. */
> + w->nlimbs = (u->nlimbs - (w->d[u->nlimbs - 1] == 0));
> + w->sign = 0;
> + }
> + }
> +
> + mpi_normalize(w);
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(mpi_sub_ui);
> --
> 2.26.2
>
>
>
>
next prev parent reply other threads:[~2020-07-10 14:42 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-10 10:09 [PATCH 0/3] DH: SP800-56A rev 3 compliant shared secret Stephan Müller
2020-07-10 10:10 ` [PATCH 1/3] crypto: ECDH - check validity of Z before export Stephan Müller
2020-07-10 10:10 ` [PATCH 2/3] lib/mpi: Add mpi_sub_ui() Stephan Müller
2020-07-10 14:42 ` Ard Biesheuvel [this message]
2020-07-10 15:10 ` Stephan Mueller
2020-07-10 10:15 ` [PATCH 3/3] crypto: DH - check validity of Z before export Stephan Müller
2020-07-12 16:38 ` [PATCH v2 0/5] DH: SP800-56A rev 3 compliant validation checks Stephan Müller
2020-07-12 16:39 ` [PATCH v2 1/5] crypto: ECDH - check validity of Z before export Stephan Müller
2020-07-12 18:02 ` Vitaly Chikunov
2020-07-15 13:17 ` Marcelo Henrique Cerri
2020-07-12 16:39 ` [PATCH v2 2/5] lib/mpi: Add mpi_sub_ui() Stephan Müller
2020-07-16 7:30 ` Herbert Xu
2020-07-16 8:41 ` Ard Biesheuvel
2020-07-16 12:50 ` Marcelo Henrique Cerri
2020-07-16 13:09 ` Ard Biesheuvel
2020-07-16 13:41 ` Marcelo Henrique Cerri
2020-07-16 13:53 ` Ard Biesheuvel
2020-07-16 14:23 ` Marcelo Henrique Cerri
2020-07-16 14:37 ` Ard Biesheuvel
2020-07-16 14:56 ` Marcelo Henrique Cerri
2020-07-16 15:20 ` Ard Biesheuvel
2020-07-12 16:40 ` [PATCH v2 3/5] crypto: DH - check validity of Z before export Stephan Müller
2020-07-15 13:17 ` Marcelo Henrique Cerri
2020-07-12 16:40 ` [PATCH v2 4/5] crypto: DH SP800-56A rev 3 local public key validation Stephan Müller
2020-07-15 13:18 ` Marcelo Henrique Cerri
2020-07-12 16:42 ` [PATCH v2 5/5] crypto: ECDH " Stephan Müller
2020-07-12 18:06 ` Vitaly Chikunov
2020-07-13 5:04 ` Stephan Mueller
2020-07-13 5:59 ` Vitaly Chikunov
2020-07-13 6:02 ` Stephan Müller
2020-07-15 13:19 ` Marcelo Henrique Cerri
2020-07-20 17:05 ` [PATCH v3 0/5] DH: SP800-56A rev 3 compliant validation checks Stephan Müller
2020-07-20 17:07 ` [PATCH v3 1/5] crypto: ECDH - check validity of Z before export Stephan Müller
2020-07-22 13:11 ` Vitaly Chikunov
2020-07-24 17:47 ` Neil Horman
2020-07-20 17:08 ` [PATCH v3 2/5] lib/mpi: Add mpi_sub_ui() Stephan Müller
2020-07-20 17:08 ` [PATCH v3 3/5] crypto: DH - check validity of Z before export Stephan Müller
2020-07-24 18:02 ` Neil Horman
2020-07-20 17:08 ` [PATCH v3 4/5] crypto: DH SP800-56A rev 3 local public key validation Stephan Müller
2020-07-20 17:09 ` [PATCH v3 5/5] crypto: ECDH " Stephan Müller
2020-07-21 11:35 ` [PATCH v3 0/5] DH: SP800-56A rev 3 compliant validation checks Marcelo Henrique Cerri
2020-07-31 13:29 ` Herbert Xu
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