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)
29 typedef uint64_t word_t, mask_t;
30 typedef uint128_t dword_t;
31 typedef int32_t hsword_t;
32 typedef int64_t sword_t;
33 typedef int128_t dsword_t;
34 # elif (ARCH_WORD_BITS == 32)
35 typedef uint32_t word_t, mask_t;
36 typedef uint64_t dword_t;
37 typedef int16_t hsword_t;
38 typedef int32_t sword_t;
39 typedef 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 */
mask_to_bool(mask_t m)66 static ossl_inline c448_bool_t mask_to_bool(mask_t m)
67 {
68 return (c448_sword_t)(sword_t)m;
69 }
70
bool_to_mask(c448_bool_t m)71 static 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