1/*
2 * Copyright 2017-2021 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright 2014 Cryptography Research, Inc.
4 *
5 * Licensed under the Apache License 2.0 (the "License").  You may not use
6 * this file except in compliance with the License.  You can obtain a copy
7 * in the file LICENSE in the source distribution or at
8 * https://www.openssl.org/source/license.html
9 *
10 * Originally written by Mike Hamburg
11 */
12
13#ifndef OSSL_CRYPTO_EC_CURVE448_WORD_H
14# define OSSL_CRYPTO_EC_CURVE448_WORD_H
15
16# include <string.h>
17# include <assert.h>
18# include <stdlib.h>
19# include <openssl/e_os2.h>
20# include "curve448utils.h"
21
22# ifdef INT128_MAX
23#  include "arch_64/arch_intrinsics.h"
24# else
25#  include "arch_32/arch_intrinsics.h"
26# endif
27
28# if (ARCH_WORD_BITS == 64)
29typedef uint64_t word_t, mask_t;
30typedef uint128_t dword_t;
31typedef int32_t hsword_t;
32typedef int64_t sword_t;
33typedef int128_t dsword_t;
34# elif (ARCH_WORD_BITS == 32)
35typedef uint32_t word_t, mask_t;
36typedef uint64_t dword_t;
37typedef int16_t hsword_t;
38typedef int32_t sword_t;
39typedef int64_t dsword_t;
40# else
41#  error "For now, we only support 32- and 64-bit architectures."
42# endif
43
44/*
45 * Scalar limbs are keyed off of the API word size instead of the arch word
46 * size.
47 */
48# if C448_WORD_BITS == 64
49#  define SC_LIMB(x) (x)
50# elif C448_WORD_BITS == 32
51#  define SC_LIMB(x) ((uint32_t)(x)),((x) >> 32)
52# else
53#  error "For now we only support 32- and 64-bit architectures."
54# endif
55
56/*
57 * The plan on booleans: The external interface uses c448_bool_t, but this
58 * might be a different size than our particular arch's word_t (and thus
59 * mask_t).  Also, the caller isn't guaranteed to pass it as nonzero.  So
60 * bool_to_mask converts word sizes and checks nonzero. On the flip side,
61 * mask_t is always -1 or 0, but it might be a different size than
62 * c448_bool_t. On the third hand, we have success vs boolean types, but
63 * that's handled in common.h: it converts between c448_bool_t and
64 * c448_error_t.
65 */
66static ossl_inline c448_bool_t mask_to_bool(mask_t m)
67{
68    return (c448_sword_t)(sword_t)m;
69}
70
71static ossl_inline mask_t bool_to_mask(c448_bool_t m)
72{
73    /* On most arches this will be optimized to a simple cast. */
74    mask_t ret = 0;
75    unsigned int i;
76    unsigned int limit = sizeof(c448_bool_t) / sizeof(mask_t);
77
78    if (limit < 1)
79        limit = 1;
80    for (i = 0; i < limit; i++)
81        ret |= ~word_is_zero(m >> (i * 8 * sizeof(word_t)));
82
83    return ret;
84}
85
86#endif                          /* OSSL_CRYPTO_EC_CURVE448_WORD_H */
87