diff options
author | Tony Lindgren <tony@atomide.com> | 2012-02-17 18:12:36 -0500 |
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committer | Tony Lindgren <tony@atomide.com> | 2012-02-17 18:12:36 -0500 |
commit | 4d68c05ce11f4cdf6a6392f3a18dc6a985b4d0c4 (patch) | |
tree | 72e500b97c4bdcb9631209f3121f42b05ae30fea /lib/mpi/mpicoder.c | |
parent | 40c0591f0a349ec074357e05c6ab1a3bc951807c (diff) | |
parent | 19bfb76ca32f8e4fa80746608ff4a77707f40520 (diff) |
Merge branch 'for_3.4/dt_base' of git://git.kernel.org/pub/scm/linux/kernel/git/bcousson/linux-omap-dt into dt
Diffstat (limited to 'lib/mpi/mpicoder.c')
-rw-r--r-- | lib/mpi/mpicoder.c | 280 |
1 files changed, 280 insertions, 0 deletions
diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c new file mode 100644 index 000000000000..f26b41fcb48c --- /dev/null +++ b/lib/mpi/mpicoder.c | |||
@@ -0,0 +1,280 @@ | |||
1 | /* mpicoder.c - Coder for the external representation of MPIs | ||
2 | * Copyright (C) 1998, 1999 Free Software Foundation, Inc. | ||
3 | * | ||
4 | * This file is part of GnuPG. | ||
5 | * | ||
6 | * GnuPG is free software; you can redistribute it and/or modify | ||
7 | * it under the terms of the GNU General Public License as published by | ||
8 | * the Free Software Foundation; either version 2 of the License, or | ||
9 | * (at your option) any later version. | ||
10 | * | ||
11 | * GnuPG is distributed in the hope that it will be useful, | ||
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
14 | * GNU General Public License for more details. | ||
15 | * | ||
16 | * You should have received a copy of the GNU General Public License | ||
17 | * along with this program; if not, write to the Free Software | ||
18 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA | ||
19 | */ | ||
20 | |||
21 | #include "mpi-internal.h" | ||
22 | |||
23 | #define MAX_EXTERN_MPI_BITS 16384 | ||
24 | |||
25 | MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread) | ||
26 | { | ||
27 | const uint8_t *buffer = xbuffer; | ||
28 | int i, j; | ||
29 | unsigned nbits, nbytes, nlimbs, nread = 0; | ||
30 | mpi_limb_t a; | ||
31 | MPI val = NULL; | ||
32 | |||
33 | if (*ret_nread < 2) | ||
34 | goto leave; | ||
35 | nbits = buffer[0] << 8 | buffer[1]; | ||
36 | |||
37 | if (nbits > MAX_EXTERN_MPI_BITS) { | ||
38 | pr_info("MPI: mpi too large (%u bits)\n", nbits); | ||
39 | goto leave; | ||
40 | } | ||
41 | buffer += 2; | ||
42 | nread = 2; | ||
43 | |||
44 | nbytes = (nbits + 7) / 8; | ||
45 | nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB; | ||
46 | val = mpi_alloc(nlimbs); | ||
47 | if (!val) | ||
48 | return NULL; | ||
49 | i = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB; | ||
50 | i %= BYTES_PER_MPI_LIMB; | ||
51 | val->nbits = nbits; | ||
52 | j = val->nlimbs = nlimbs; | ||
53 | val->sign = 0; | ||
54 | for (; j > 0; j--) { | ||
55 | a = 0; | ||
56 | for (; i < BYTES_PER_MPI_LIMB; i++) { | ||
57 | if (++nread > *ret_nread) { | ||
58 | printk | ||
59 | ("MPI: mpi larger than buffer nread=%d ret_nread=%d\n", | ||
60 | nread, *ret_nread); | ||
61 | goto leave; | ||
62 | } | ||
63 | a <<= 8; | ||
64 | a |= *buffer++; | ||
65 | } | ||
66 | i = 0; | ||
67 | val->d[j - 1] = a; | ||
68 | } | ||
69 | |||
70 | leave: | ||
71 | *ret_nread = nread; | ||
72 | return val; | ||
73 | } | ||
74 | EXPORT_SYMBOL_GPL(mpi_read_from_buffer); | ||
75 | |||
76 | /**************** | ||
77 | * Make an mpi from a character string. | ||
78 | */ | ||
79 | int mpi_fromstr(MPI val, const char *str) | ||
80 | { | ||
81 | int hexmode = 0, sign = 0, prepend_zero = 0, i, j, c, c1, c2; | ||
82 | unsigned nbits, nbytes, nlimbs; | ||
83 | mpi_limb_t a; | ||
84 | |||
85 | if (*str == '-') { | ||
86 | sign = 1; | ||
87 | str++; | ||
88 | } | ||
89 | if (*str == '0' && str[1] == 'x') | ||
90 | hexmode = 1; | ||
91 | else | ||
92 | return -EINVAL; /* other bases are not yet supported */ | ||
93 | str += 2; | ||
94 | |||
95 | nbits = strlen(str) * 4; | ||
96 | if (nbits % 8) | ||
97 | prepend_zero = 1; | ||
98 | nbytes = (nbits + 7) / 8; | ||
99 | nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB; | ||
100 | if (val->alloced < nlimbs) | ||
101 | if (!mpi_resize(val, nlimbs)) | ||
102 | return -ENOMEM; | ||
103 | i = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB; | ||
104 | i %= BYTES_PER_MPI_LIMB; | ||
105 | j = val->nlimbs = nlimbs; | ||
106 | val->sign = sign; | ||
107 | for (; j > 0; j--) { | ||
108 | a = 0; | ||
109 | for (; i < BYTES_PER_MPI_LIMB; i++) { | ||
110 | if (prepend_zero) { | ||
111 | c1 = '0'; | ||
112 | prepend_zero = 0; | ||
113 | } else | ||
114 | c1 = *str++; | ||
115 | assert(c1); | ||
116 | c2 = *str++; | ||
117 | assert(c2); | ||
118 | if (c1 >= '0' && c1 <= '9') | ||
119 | c = c1 - '0'; | ||
120 | else if (c1 >= 'a' && c1 <= 'f') | ||
121 | c = c1 - 'a' + 10; | ||
122 | else if (c1 >= 'A' && c1 <= 'F') | ||
123 | c = c1 - 'A' + 10; | ||
124 | else { | ||
125 | mpi_clear(val); | ||
126 | return 1; | ||
127 | } | ||
128 | c <<= 4; | ||
129 | if (c2 >= '0' && c2 <= '9') | ||
130 | c |= c2 - '0'; | ||
131 | else if (c2 >= 'a' && c2 <= 'f') | ||
132 | c |= c2 - 'a' + 10; | ||
133 | else if (c2 >= 'A' && c2 <= 'F') | ||
134 | c |= c2 - 'A' + 10; | ||
135 | else { | ||
136 | mpi_clear(val); | ||
137 | return 1; | ||
138 | } | ||
139 | a <<= 8; | ||
140 | a |= c; | ||
141 | } | ||
142 | i = 0; | ||
143 | |||
144 | val->d[j - 1] = a; | ||
145 | } | ||
146 | |||
147 | return 0; | ||
148 | } | ||
149 | EXPORT_SYMBOL_GPL(mpi_fromstr); | ||
150 | |||
151 | /**************** | ||
152 | * Return an allocated buffer with the MPI (msb first). | ||
153 | * NBYTES receives the length of this buffer. Caller must free the | ||
154 | * return string (This function does return a 0 byte buffer with NBYTES | ||
155 | * set to zero if the value of A is zero. If sign is not NULL, it will | ||
156 | * be set to the sign of the A. | ||
157 | */ | ||
158 | void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign) | ||
159 | { | ||
160 | uint8_t *p, *buffer; | ||
161 | mpi_limb_t alimb; | ||
162 | int i; | ||
163 | unsigned int n; | ||
164 | |||
165 | if (sign) | ||
166 | *sign = a->sign; | ||
167 | *nbytes = n = a->nlimbs * BYTES_PER_MPI_LIMB; | ||
168 | if (!n) | ||
169 | n++; /* avoid zero length allocation */ | ||
170 | p = buffer = kmalloc(n, GFP_KERNEL); | ||
171 | if (!p) | ||
172 | return NULL; | ||
173 | |||
174 | for (i = a->nlimbs - 1; i >= 0; i--) { | ||
175 | alimb = a->d[i]; | ||
176 | #if BYTES_PER_MPI_LIMB == 4 | ||
177 | *p++ = alimb >> 24; | ||
178 | *p++ = alimb >> 16; | ||
179 | *p++ = alimb >> 8; | ||
180 | *p++ = alimb; | ||
181 | #elif BYTES_PER_MPI_LIMB == 8 | ||
182 | *p++ = alimb >> 56; | ||
183 | *p++ = alimb >> 48; | ||
184 | *p++ = alimb >> 40; | ||
185 | *p++ = alimb >> 32; | ||
186 | *p++ = alimb >> 24; | ||
187 | *p++ = alimb >> 16; | ||
188 | *p++ = alimb >> 8; | ||
189 | *p++ = alimb; | ||
190 | #else | ||
191 | #error please implement for this limb size. | ||
192 | #endif | ||
193 | } | ||
194 | |||
195 | /* this is sub-optimal but we need to do the shift operation | ||
196 | * because the caller has to free the returned buffer */ | ||
197 | for (p = buffer; !*p && *nbytes; p++, --*nbytes) | ||
198 | ; | ||
199 | if (p != buffer) | ||
200 | memmove(buffer, p, *nbytes); | ||
201 | |||
202 | return buffer; | ||
203 | } | ||
204 | EXPORT_SYMBOL_GPL(mpi_get_buffer); | ||
205 | |||
206 | /**************** | ||
207 | * Use BUFFER to update MPI. | ||
208 | */ | ||
209 | int mpi_set_buffer(MPI a, const void *xbuffer, unsigned nbytes, int sign) | ||
210 | { | ||
211 | const uint8_t *buffer = xbuffer, *p; | ||
212 | mpi_limb_t alimb; | ||
213 | int nlimbs; | ||
214 | int i; | ||
215 | |||
216 | nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB; | ||
217 | if (RESIZE_IF_NEEDED(a, nlimbs) < 0) | ||
218 | return -ENOMEM; | ||
219 | a->sign = sign; | ||
220 | |||
221 | for (i = 0, p = buffer + nbytes - 1; p >= buffer + BYTES_PER_MPI_LIMB;) { | ||
222 | #if BYTES_PER_MPI_LIMB == 4 | ||
223 | alimb = (mpi_limb_t) *p--; | ||
224 | alimb |= (mpi_limb_t) *p-- << 8; | ||
225 | alimb |= (mpi_limb_t) *p-- << 16; | ||
226 | alimb |= (mpi_limb_t) *p-- << 24; | ||
227 | #elif BYTES_PER_MPI_LIMB == 8 | ||
228 | alimb = (mpi_limb_t) *p--; | ||
229 | alimb |= (mpi_limb_t) *p-- << 8; | ||
230 | alimb |= (mpi_limb_t) *p-- << 16; | ||
231 | alimb |= (mpi_limb_t) *p-- << 24; | ||
232 | alimb |= (mpi_limb_t) *p-- << 32; | ||
233 | alimb |= (mpi_limb_t) *p-- << 40; | ||
234 | alimb |= (mpi_limb_t) *p-- << 48; | ||
235 | alimb |= (mpi_limb_t) *p-- << 56; | ||
236 | #else | ||
237 | #error please implement for this limb size. | ||
238 | #endif | ||
239 | a->d[i++] = alimb; | ||
240 | } | ||
241 | if (p >= buffer) { | ||
242 | #if BYTES_PER_MPI_LIMB == 4 | ||
243 | alimb = *p--; | ||
244 | if (p >= buffer) | ||
245 | alimb |= (mpi_limb_t) *p-- << 8; | ||
246 | if (p >= buffer) | ||
247 | alimb |= (mpi_limb_t) *p-- << 16; | ||
248 | if (p >= buffer) | ||
249 | alimb |= (mpi_limb_t) *p-- << 24; | ||
250 | #elif BYTES_PER_MPI_LIMB == 8 | ||
251 | alimb = (mpi_limb_t) *p--; | ||
252 | if (p >= buffer) | ||
253 | alimb |= (mpi_limb_t) *p-- << 8; | ||
254 | if (p >= buffer) | ||
255 | alimb |= (mpi_limb_t) *p-- << 16; | ||
256 | if (p >= buffer) | ||
257 | alimb |= (mpi_limb_t) *p-- << 24; | ||
258 | if (p >= buffer) | ||
259 | alimb |= (mpi_limb_t) *p-- << 32; | ||
260 | if (p >= buffer) | ||
261 | alimb |= (mpi_limb_t) *p-- << 40; | ||
262 | if (p >= buffer) | ||
263 | alimb |= (mpi_limb_t) *p-- << 48; | ||
264 | if (p >= buffer) | ||
265 | alimb |= (mpi_limb_t) *p-- << 56; | ||
266 | #else | ||
267 | #error please implement for this limb size. | ||
268 | #endif | ||
269 | a->d[i++] = alimb; | ||
270 | } | ||
271 | a->nlimbs = i; | ||
272 | |||
273 | if (i != nlimbs) { | ||
274 | pr_emerg("MPI: mpi_set_buffer: Assertion failed (%d != %d)", i, | ||
275 | nlimbs); | ||
276 | BUG(); | ||
277 | } | ||
278 | return 0; | ||
279 | } | ||
280 | EXPORT_SYMBOL_GPL(mpi_set_buffer); | ||