/src/openssl/crypto/bn/bn_conv.c
Line | Count | Source (jump to first uncovered line) |
1 | | /* |
2 | | * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved. |
3 | | * |
4 | | * Licensed under the Apache License 2.0 (the "License"). You may not use |
5 | | * this file except in compliance with the License. You can obtain a copy |
6 | | * in the file LICENSE in the source distribution or at |
7 | | * https://www.openssl.org/source/license.html |
8 | | */ |
9 | | |
10 | | #include <openssl/err.h> |
11 | | #include "crypto/ctype.h" |
12 | | #include "bn_local.h" |
13 | | |
14 | | static const char Hex[] = "0123456789ABCDEF"; |
15 | | |
16 | | /* Must 'OPENSSL_free' the returned data */ |
17 | | char *BN_bn2hex(const BIGNUM *a) |
18 | 4.82k | { |
19 | 4.82k | int i, j, v, z = 0; |
20 | 4.82k | char *buf; |
21 | 4.82k | char *p; |
22 | | |
23 | 4.82k | if (BN_is_zero(a)) |
24 | 13 | return OPENSSL_strdup("0"); |
25 | 4.81k | buf = OPENSSL_malloc(a->top * BN_BYTES * 2 + 2); |
26 | 4.81k | if (buf == NULL) |
27 | 0 | goto err; |
28 | 4.81k | p = buf; |
29 | 4.81k | if (a->neg) |
30 | 478 | *p++ = '-'; |
31 | 557k | for (i = a->top - 1; i >= 0; i--) { |
32 | 4.97M | for (j = BN_BITS2 - 8; j >= 0; j -= 8) { |
33 | | /* strip leading zeros */ |
34 | 4.42M | v = (int)((a->d[i] >> j) & 0xff); |
35 | 4.42M | if (z || v != 0) { |
36 | 4.40M | *p++ = Hex[v >> 4]; |
37 | 4.40M | *p++ = Hex[v & 0x0f]; |
38 | 4.40M | z = 1; |
39 | 4.40M | } |
40 | 4.42M | } |
41 | 552k | } |
42 | 4.81k | *p = '\0'; |
43 | 4.81k | err: |
44 | 4.81k | return buf; |
45 | 4.81k | } |
46 | | |
47 | | #ifndef FIPS_MODULE |
48 | | /* No BIO_snprintf in FIPS_MODULE */ |
49 | | /* Must 'OPENSSL_free' the returned data */ |
50 | | char *BN_bn2dec(const BIGNUM *a) |
51 | 14.9k | { |
52 | 14.9k | int i = 0, num, ok = 0, n, tbytes; |
53 | 14.9k | char *buf = NULL; |
54 | 14.9k | char *p; |
55 | 14.9k | BIGNUM *t = NULL; |
56 | 14.9k | BN_ULONG *bn_data = NULL, *lp; |
57 | 14.9k | int bn_data_num; |
58 | | |
59 | | /*- |
60 | | * get an upper bound for the length of the decimal integer |
61 | | * num <= (BN_num_bits(a) + 1) * log(2) |
62 | | * <= 3 * BN_num_bits(a) * 0.101 + log(2) + 1 (rounding error) |
63 | | * <= 3 * BN_num_bits(a) / 10 + 3 * BN_num_bits / 1000 + 1 + 1 |
64 | | */ |
65 | 14.9k | i = BN_num_bits(a) * 3; |
66 | 14.9k | num = (i / 10 + i / 1000 + 1) + 1; |
67 | 14.9k | tbytes = num + 3; /* negative and terminator and one spare? */ |
68 | 14.9k | bn_data_num = num / BN_DEC_NUM + 1; |
69 | 14.9k | bn_data = OPENSSL_malloc(bn_data_num * sizeof(BN_ULONG)); |
70 | 14.9k | buf = OPENSSL_malloc(tbytes); |
71 | 14.9k | if (buf == NULL || bn_data == NULL) |
72 | 0 | goto err; |
73 | 14.9k | if ((t = BN_dup(a)) == NULL) |
74 | 0 | goto err; |
75 | | |
76 | 14.9k | p = buf; |
77 | 14.9k | lp = bn_data; |
78 | 14.9k | if (BN_is_zero(t)) { |
79 | 1.86k | *p++ = '0'; |
80 | 1.86k | *p++ = '\0'; |
81 | 13.1k | } else { |
82 | 13.1k | if (BN_is_negative(t)) |
83 | 3.00k | *p++ = '-'; |
84 | | |
85 | 31.6k | while (!BN_is_zero(t)) { |
86 | 18.4k | if (lp - bn_data >= bn_data_num) |
87 | 0 | goto err; |
88 | 18.4k | *lp = BN_div_word(t, BN_DEC_CONV); |
89 | 18.4k | if (*lp == (BN_ULONG)-1) |
90 | 0 | goto err; |
91 | 18.4k | lp++; |
92 | 18.4k | } |
93 | 13.1k | lp--; |
94 | | /* |
95 | | * We now have a series of blocks, BN_DEC_NUM chars in length, where |
96 | | * the last one needs truncation. The blocks need to be reversed in |
97 | | * order. |
98 | | */ |
99 | 13.1k | n = BIO_snprintf(p, tbytes - (size_t)(p - buf), BN_DEC_FMT1, *lp); |
100 | 13.1k | if (n < 0) |
101 | 0 | goto err; |
102 | 13.1k | p += n; |
103 | 18.4k | while (lp != bn_data) { |
104 | 5.35k | lp--; |
105 | 5.35k | n = BIO_snprintf(p, tbytes - (size_t)(p - buf), BN_DEC_FMT2, *lp); |
106 | 5.35k | if (n < 0) |
107 | 0 | goto err; |
108 | 5.35k | p += n; |
109 | 5.35k | } |
110 | 13.1k | } |
111 | 14.9k | ok = 1; |
112 | 14.9k | err: |
113 | 14.9k | OPENSSL_free(bn_data); |
114 | 14.9k | BN_free(t); |
115 | 14.9k | if (ok) |
116 | 14.9k | return buf; |
117 | 0 | OPENSSL_free(buf); |
118 | 0 | return NULL; |
119 | 14.9k | } |
120 | | #endif |
121 | | |
122 | | int BN_hex2bn(BIGNUM **bn, const char *a) |
123 | 0 | { |
124 | 0 | BIGNUM *ret = NULL; |
125 | 0 | BN_ULONG l = 0; |
126 | 0 | int neg = 0, h, m, i, j, k, c; |
127 | 0 | int num; |
128 | |
|
129 | 0 | if (a == NULL || *a == '\0') |
130 | 0 | return 0; |
131 | | |
132 | 0 | if (*a == '-') { |
133 | 0 | neg = 1; |
134 | 0 | a++; |
135 | 0 | } |
136 | |
|
137 | 0 | for (i = 0; i <= INT_MAX / 4 && ossl_isxdigit(a[i]); i++) |
138 | 0 | continue; |
139 | |
|
140 | 0 | if (i == 0 || i > INT_MAX / 4) |
141 | 0 | return 0; |
142 | | |
143 | 0 | num = i + neg; |
144 | 0 | if (bn == NULL) |
145 | 0 | return num; |
146 | | |
147 | | /* a is the start of the hex digits, and it is 'i' long */ |
148 | 0 | if (*bn == NULL) { |
149 | 0 | if ((ret = BN_new()) == NULL) |
150 | 0 | return 0; |
151 | 0 | } else { |
152 | 0 | ret = *bn; |
153 | 0 | if (BN_get_flags(ret, BN_FLG_STATIC_DATA)) { |
154 | 0 | ERR_raise(ERR_LIB_BN, ERR_R_PASSED_INVALID_ARGUMENT); |
155 | 0 | return 0; |
156 | 0 | } |
157 | 0 | BN_zero(ret); |
158 | 0 | } |
159 | | |
160 | | /* i is the number of hex digits */ |
161 | 0 | if (bn_expand(ret, i * 4) == NULL) |
162 | 0 | goto err; |
163 | | |
164 | 0 | j = i; /* least significant 'hex' */ |
165 | 0 | m = 0; |
166 | 0 | h = 0; |
167 | 0 | while (j > 0) { |
168 | 0 | m = (BN_BYTES * 2 <= j) ? BN_BYTES * 2 : j; |
169 | 0 | l = 0; |
170 | 0 | for (;;) { |
171 | 0 | c = a[j - m]; |
172 | 0 | k = OPENSSL_hexchar2int(c); |
173 | 0 | if (k < 0) |
174 | 0 | k = 0; /* paranoia */ |
175 | 0 | l = (l << 4) | k; |
176 | |
|
177 | 0 | if (--m <= 0) { |
178 | 0 | ret->d[h++] = l; |
179 | 0 | break; |
180 | 0 | } |
181 | 0 | } |
182 | 0 | j -= BN_BYTES * 2; |
183 | 0 | } |
184 | 0 | ret->top = h; |
185 | 0 | bn_correct_top(ret); |
186 | |
|
187 | 0 | *bn = ret; |
188 | 0 | bn_check_top(ret); |
189 | | /* Don't set the negative flag if it's zero. */ |
190 | 0 | if (ret->top != 0) |
191 | 0 | ret->neg = neg; |
192 | 0 | return num; |
193 | 0 | err: |
194 | 0 | if (*bn == NULL) |
195 | 0 | BN_free(ret); |
196 | 0 | return 0; |
197 | 0 | } |
198 | | |
199 | | int BN_dec2bn(BIGNUM **bn, const char *a) |
200 | 0 | { |
201 | 0 | BIGNUM *ret = NULL; |
202 | 0 | BN_ULONG l = 0; |
203 | 0 | int neg = 0, i, j; |
204 | 0 | int num; |
205 | |
|
206 | 0 | if (a == NULL || *a == '\0') |
207 | 0 | return 0; |
208 | 0 | if (*a == '-') { |
209 | 0 | neg = 1; |
210 | 0 | a++; |
211 | 0 | } |
212 | |
|
213 | 0 | for (i = 0; i <= INT_MAX / 4 && ossl_isdigit(a[i]); i++) |
214 | 0 | continue; |
215 | |
|
216 | 0 | if (i == 0 || i > INT_MAX / 4) |
217 | 0 | goto err; |
218 | | |
219 | 0 | num = i + neg; |
220 | 0 | if (bn == NULL) |
221 | 0 | return num; |
222 | | |
223 | | /* |
224 | | * a is the start of the digits, and it is 'i' long. We chop it into |
225 | | * BN_DEC_NUM digits at a time |
226 | | */ |
227 | 0 | if (*bn == NULL) { |
228 | 0 | if ((ret = BN_new()) == NULL) |
229 | 0 | return 0; |
230 | 0 | } else { |
231 | 0 | ret = *bn; |
232 | 0 | BN_zero(ret); |
233 | 0 | } |
234 | | |
235 | | /* i is the number of digits, a bit of an over expand */ |
236 | 0 | if (bn_expand(ret, i * 4) == NULL) |
237 | 0 | goto err; |
238 | | |
239 | 0 | j = BN_DEC_NUM - i % BN_DEC_NUM; |
240 | 0 | if (j == BN_DEC_NUM) |
241 | 0 | j = 0; |
242 | 0 | l = 0; |
243 | 0 | while (--i >= 0) { |
244 | 0 | l *= 10; |
245 | 0 | l += *a - '0'; |
246 | 0 | a++; |
247 | 0 | if (++j == BN_DEC_NUM) { |
248 | 0 | if (!BN_mul_word(ret, BN_DEC_CONV) |
249 | 0 | || !BN_add_word(ret, l)) |
250 | 0 | goto err; |
251 | 0 | l = 0; |
252 | 0 | j = 0; |
253 | 0 | } |
254 | 0 | } |
255 | | |
256 | 0 | bn_correct_top(ret); |
257 | 0 | *bn = ret; |
258 | 0 | bn_check_top(ret); |
259 | | /* Don't set the negative flag if it's zero. */ |
260 | 0 | if (ret->top != 0) |
261 | 0 | ret->neg = neg; |
262 | 0 | return num; |
263 | 0 | err: |
264 | 0 | if (*bn == NULL) |
265 | 0 | BN_free(ret); |
266 | 0 | return 0; |
267 | 0 | } |
268 | | |
269 | | int BN_asc2bn(BIGNUM **bn, const char *a) |
270 | 0 | { |
271 | 0 | const char *p = a; |
272 | |
|
273 | 0 | if (*p == '-') |
274 | 0 | p++; |
275 | |
|
276 | 0 | if (p[0] == '0' && (p[1] == 'X' || p[1] == 'x')) { |
277 | 0 | if (!BN_hex2bn(bn, p + 2)) |
278 | 0 | return 0; |
279 | 0 | } else { |
280 | 0 | if (!BN_dec2bn(bn, p)) |
281 | 0 | return 0; |
282 | 0 | } |
283 | | /* Don't set the negative flag if it's zero. */ |
284 | 0 | if (*a == '-' && (*bn)->top != 0) |
285 | 0 | (*bn)->neg = 1; |
286 | 0 | return 1; |
287 | 0 | } |