1/*
2 * Copyright 2017-2018 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 "arch_intrinsics.h"
21# include "curve448utils.h"
22
23# if (ARCH_WORD_BITS == 64)
24typedef uint64_t word_t, mask_t;
25typedef __uint128_t dword_t;
26typedef int32_t hsword_t;
27typedef int64_t sword_t;
28typedef __int128_t dsword_t;
29# elif (ARCH_WORD_BITS == 32)
30typedef uint32_t word_t, mask_t;
31typedef uint64_t dword_t;
32typedef int16_t hsword_t;
33typedef int32_t sword_t;
34typedef int64_t dsword_t;
35# else
36# error "For now, we only support 32- and 64-bit architectures."
37# endif
38
39/*
40 * Scalar limbs are keyed off of the API word size instead of the arch word
41 * size.
42 */
43# if C448_WORD_BITS == 64
44# define SC_LIMB(x) (x)
45# elif C448_WORD_BITS == 32
46# define SC_LIMB(x) ((uint32_t)(x)),((x) >> 32)
47# else
48# error "For now we only support 32- and 64-bit architectures."
49# endif
50
51/*
52 * The plan on booleans: The external interface uses c448_bool_t, but this
53 * might be a different size than our particular arch's word_t (and thus
54 * mask_t). Also, the caller isn't guaranteed to pass it as nonzero. So
55 * bool_to_mask converts word sizes and checks nonzero. On the flip side,
56 * mask_t is always -1 or 0, but it might be a different size than
57 * c448_bool_t. On the third hand, we have success vs boolean types, but
58 * that's handled in common.h: it converts between c448_bool_t and
59 * c448_error_t.
60 */
61static ossl_inline c448_bool_t mask_to_bool(mask_t m)
62{
63 return (c448_sword_t)(sword_t)m;
64}
65
66static ossl_inline mask_t bool_to_mask(c448_bool_t m)
67{
68 /* On most arches this will be optimized to a simple cast. */
69 mask_t ret = 0;
70 unsigned int i;
71 unsigned int limit = sizeof(c448_bool_t) / sizeof(mask_t);
72
73 if (limit < 1)
74 limit = 1;
75 for (i = 0; i < limit; i++)
76 ret |= ~word_is_zero(m >> (i * 8 * sizeof(word_t)));
77
78 return ret;
79}
80
81#endif /* OSSL_CRYPTO_EC_CURVE448_WORD_H */
82