diff options
author | Herbert Xu <herbert@gondor.apana.org.au> | 2023-08-04 17:24:34 +0800 |
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committer | Herbert Xu <herbert@gondor.apana.org.au> | 2023-08-11 19:19:27 +0800 |
commit | 2a598d0b2800aa23ba51adcf060cec524aaa63b2 (patch) | |
tree | b7c035f0fa57dab30af2768114f71f64230dac5c /lib/crypto/mpi/generic_mpih-add1.c | |
parent | 9ae4577bc077a7e32c3c7d442c95bc76865c0f17 (diff) |
crypto: lib - Move mpi into lib/crypto
As lib/mpi is mostly used by crypto code, move it under lib/crypto
so that patches touching it get directed to the right mailing list.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'lib/crypto/mpi/generic_mpih-add1.c')
-rw-r--r-- | lib/crypto/mpi/generic_mpih-add1.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/lib/crypto/mpi/generic_mpih-add1.c b/lib/crypto/mpi/generic_mpih-add1.c new file mode 100644 index 0000000000000..299308b5461c9 --- /dev/null +++ b/lib/crypto/mpi/generic_mpih-add1.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* mpihelp-add_1.c - MPI helper functions + * Copyright (C) 1994, 1996, 1997, 1998, + * 2000 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" +#include "longlong.h" + +mpi_limb_t +mpihelp_add_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, + mpi_ptr_t s2_ptr, mpi_size_t size) +{ + mpi_limb_t x, y, cy; + mpi_size_t j; + + /* The loop counter and index J goes from -SIZE to -1. This way + the loop becomes faster. */ + j = -size; + + /* Offset the base pointers to compensate for the negative indices. */ + s1_ptr -= j; + s2_ptr -= j; + res_ptr -= j; + + cy = 0; + do { + y = s2_ptr[j]; + x = s1_ptr[j]; + y += cy; /* add previous carry to one addend */ + cy = y < cy; /* get out carry from that addition */ + y += x; /* add other addend */ + cy += y < x; /* get out carry from that add, combine */ + res_ptr[j] = y; + } while (++j); + + return cy; +} |