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6fc6879b JM |
1 | /* |
2 | * Big number math | |
3 | * Copyright (c) 2006, Jouni Malinen <j@w1.fi> | |
4 | * | |
0f3d578e JM |
5 | * This software may be distributed under the terms of the BSD license. |
6 | * See README for more details. | |
6fc6879b JM |
7 | */ |
8 | ||
9 | #include "includes.h" | |
10 | ||
11 | #include "common.h" | |
12 | #include "bignum.h" | |
13 | ||
14 | #ifdef CONFIG_INTERNAL_LIBTOMMATH | |
15 | #include "libtommath.c" | |
16 | #else /* CONFIG_INTERNAL_LIBTOMMATH */ | |
17 | #include <tommath.h> | |
18 | #endif /* CONFIG_INTERNAL_LIBTOMMATH */ | |
19 | ||
20 | ||
21 | /* | |
22 | * The current version is just a wrapper for LibTomMath library, so | |
23 | * struct bignum is just typecast to mp_int. | |
24 | */ | |
25 | ||
26 | /** | |
27 | * bignum_init - Allocate memory for bignum | |
28 | * Returns: Pointer to allocated bignum or %NULL on failure | |
29 | */ | |
30 | struct bignum * bignum_init(void) | |
31 | { | |
32 | struct bignum *n = os_zalloc(sizeof(mp_int)); | |
33 | if (n == NULL) | |
34 | return NULL; | |
35 | if (mp_init((mp_int *) n) != MP_OKAY) { | |
36 | os_free(n); | |
37 | n = NULL; | |
38 | } | |
39 | return n; | |
40 | } | |
41 | ||
42 | ||
43 | /** | |
44 | * bignum_deinit - Free bignum | |
45 | * @n: Bignum from bignum_init() | |
46 | */ | |
47 | void bignum_deinit(struct bignum *n) | |
48 | { | |
49 | if (n) { | |
50 | mp_clear((mp_int *) n); | |
51 | os_free(n); | |
52 | } | |
53 | } | |
54 | ||
55 | ||
56 | /** | |
57 | * bignum_get_unsigned_bin - Get length of bignum as an unsigned binary buffer | |
58 | * @n: Bignum from bignum_init() | |
59 | * Returns: Length of n if written to a binary buffer | |
60 | */ | |
61 | size_t bignum_get_unsigned_bin_len(struct bignum *n) | |
62 | { | |
63 | return mp_unsigned_bin_size((mp_int *) n); | |
64 | } | |
65 | ||
66 | ||
67 | /** | |
68 | * bignum_get_unsigned_bin - Set binary buffer to unsigned bignum | |
69 | * @n: Bignum from bignum_init() | |
70 | * @buf: Buffer for the binary number | |
71 | * @len: Length of the buffer, can be %NULL if buffer is known to be long | |
72 | * enough. Set to used buffer length on success if not %NULL. | |
73 | * Returns: 0 on success, -1 on failure | |
74 | */ | |
75 | int bignum_get_unsigned_bin(const struct bignum *n, u8 *buf, size_t *len) | |
76 | { | |
77 | size_t need = mp_unsigned_bin_size((mp_int *) n); | |
78 | if (len && need > *len) { | |
79 | *len = need; | |
80 | return -1; | |
81 | } | |
82 | if (mp_to_unsigned_bin((mp_int *) n, buf) != MP_OKAY) { | |
83 | wpa_printf(MSG_DEBUG, "BIGNUM: %s failed", __func__); | |
84 | return -1; | |
85 | } | |
86 | if (len) | |
87 | *len = need; | |
88 | return 0; | |
89 | } | |
90 | ||
91 | ||
92 | /** | |
93 | * bignum_set_unsigned_bin - Set bignum based on unsigned binary buffer | |
a17df5fb | 94 | * @n: Bignum from bignum_init(); to be set to the given value |
6fc6879b JM |
95 | * @buf: Buffer with unsigned binary value |
96 | * @len: Length of buf in octets | |
97 | * Returns: 0 on success, -1 on failure | |
98 | */ | |
99 | int bignum_set_unsigned_bin(struct bignum *n, const u8 *buf, size_t len) | |
100 | { | |
101 | if (mp_read_unsigned_bin((mp_int *) n, (u8 *) buf, len) != MP_OKAY) { | |
102 | wpa_printf(MSG_DEBUG, "BIGNUM: %s failed", __func__); | |
103 | return -1; | |
104 | } | |
105 | return 0; | |
106 | } | |
107 | ||
108 | ||
109 | /** | |
110 | * bignum_cmp - Signed comparison | |
111 | * @a: Bignum from bignum_init() | |
112 | * @b: Bignum from bignum_init() | |
113 | * Returns: 0 on success, -1 on failure | |
114 | */ | |
115 | int bignum_cmp(const struct bignum *a, const struct bignum *b) | |
116 | { | |
117 | return mp_cmp((mp_int *) a, (mp_int *) b); | |
118 | } | |
119 | ||
120 | ||
121 | /** | |
122 | * bignum_cmd_d - Compare bignum to standard integer | |
123 | * @a: Bignum from bignum_init() | |
124 | * @b: Small integer | |
125 | * Returns: 0 on success, -1 on failure | |
126 | */ | |
127 | int bignum_cmp_d(const struct bignum *a, unsigned long b) | |
128 | { | |
129 | return mp_cmp_d((mp_int *) a, b); | |
130 | } | |
131 | ||
132 | ||
133 | /** | |
134 | * bignum_add - c = a + b | |
135 | * @a: Bignum from bignum_init() | |
136 | * @b: Bignum from bignum_init() | |
137 | * @c: Bignum from bignum_init(); used to store the result of a + b | |
138 | * Returns: 0 on success, -1 on failure | |
139 | */ | |
140 | int bignum_add(const struct bignum *a, const struct bignum *b, | |
141 | struct bignum *c) | |
142 | { | |
143 | if (mp_add((mp_int *) a, (mp_int *) b, (mp_int *) c) != MP_OKAY) { | |
144 | wpa_printf(MSG_DEBUG, "BIGNUM: %s failed", __func__); | |
145 | return -1; | |
146 | } | |
147 | return 0; | |
148 | } | |
149 | ||
150 | ||
151 | /** | |
152 | * bignum_sub - c = a - b | |
153 | * @a: Bignum from bignum_init() | |
154 | * @b: Bignum from bignum_init() | |
155 | * @c: Bignum from bignum_init(); used to store the result of a - b | |
156 | * Returns: 0 on success, -1 on failure | |
157 | */ | |
158 | int bignum_sub(const struct bignum *a, const struct bignum *b, | |
159 | struct bignum *c) | |
160 | { | |
161 | if (mp_sub((mp_int *) a, (mp_int *) b, (mp_int *) c) != MP_OKAY) { | |
162 | wpa_printf(MSG_DEBUG, "BIGNUM: %s failed", __func__); | |
163 | return -1; | |
164 | } | |
165 | return 0; | |
166 | } | |
167 | ||
168 | ||
169 | /** | |
170 | * bignum_mul - c = a * b | |
171 | * @a: Bignum from bignum_init() | |
172 | * @b: Bignum from bignum_init() | |
173 | * @c: Bignum from bignum_init(); used to store the result of a * b | |
174 | * Returns: 0 on success, -1 on failure | |
175 | */ | |
176 | int bignum_mul(const struct bignum *a, const struct bignum *b, | |
177 | struct bignum *c) | |
178 | { | |
179 | if (mp_mul((mp_int *) a, (mp_int *) b, (mp_int *) c) != MP_OKAY) { | |
180 | wpa_printf(MSG_DEBUG, "BIGNUM: %s failed", __func__); | |
181 | return -1; | |
182 | } | |
183 | return 0; | |
184 | } | |
185 | ||
186 | ||
187 | /** | |
188 | * bignum_mulmod - d = a * b (mod c) | |
189 | * @a: Bignum from bignum_init() | |
190 | * @b: Bignum from bignum_init() | |
191 | * @c: Bignum from bignum_init(); modulus | |
192 | * @d: Bignum from bignum_init(); used to store the result of a * b (mod c) | |
193 | * Returns: 0 on success, -1 on failure | |
194 | */ | |
195 | int bignum_mulmod(const struct bignum *a, const struct bignum *b, | |
196 | const struct bignum *c, struct bignum *d) | |
197 | { | |
198 | if (mp_mulmod((mp_int *) a, (mp_int *) b, (mp_int *) c, (mp_int *) d) | |
199 | != MP_OKAY) { | |
200 | wpa_printf(MSG_DEBUG, "BIGNUM: %s failed", __func__); | |
201 | return -1; | |
202 | } | |
203 | return 0; | |
204 | } | |
205 | ||
206 | ||
207 | /** | |
208 | * bignum_exptmod - Modular exponentiation: d = a^b (mod c) | |
209 | * @a: Bignum from bignum_init(); base | |
210 | * @b: Bignum from bignum_init(); exponent | |
211 | * @c: Bignum from bignum_init(); modulus | |
212 | * @d: Bignum from bignum_init(); used to store the result of a^b (mod c) | |
213 | * Returns: 0 on success, -1 on failure | |
214 | */ | |
215 | int bignum_exptmod(const struct bignum *a, const struct bignum *b, | |
216 | const struct bignum *c, struct bignum *d) | |
217 | { | |
218 | if (mp_exptmod((mp_int *) a, (mp_int *) b, (mp_int *) c, (mp_int *) d) | |
219 | != MP_OKAY) { | |
220 | wpa_printf(MSG_DEBUG, "BIGNUM: %s failed", __func__); | |
221 | return -1; | |
222 | } | |
223 | return 0; | |
224 | } |