[efi] Disable EFI watchdog timer when shutting down to boot an OS
[ipxe.git] / src / crypto / md5.c
1 /*
2 * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 * 02110-1301, USA.
18 *
19 * You can also choose to distribute this program under the terms of
20 * the Unmodified Binary Distribution Licence (as given in the file
21 * COPYING.UBDL), provided that you have satisfied its requirements.
22 */
23
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
25
26 /** @file
27 *
28 * MD5 algorithm
29 *
30 */
31
32 #include <stdint.h>
33 #include <string.h>
34 #include <byteswap.h>
35 #include <assert.h>
36 #include <ipxe/rotate.h>
37 #include <ipxe/crypto.h>
38 #include <ipxe/md5.h>
39
40 /** MD5 variables */
41 struct md5_variables {
42 /* This layout matches that of struct md5_digest_data,
43 * allowing for efficient endianness-conversion,
44 */
45 uint32_t a;
46 uint32_t b;
47 uint32_t c;
48 uint32_t d;
49 uint32_t w[16];
50 } __attribute__ (( packed ));
51
52 /** MD5 constants */
53 static const uint32_t k[64] = {
54 0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee, 0xf57c0faf, 0x4787c62a,
55 0xa8304613, 0xfd469501, 0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
56 0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821, 0xf61e2562, 0xc040b340,
57 0x265e5a51, 0xe9b6c7aa, 0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8,
58 0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed, 0xa9e3e905, 0xfcefa3f8,
59 0x676f02d9, 0x8d2a4c8a, 0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
60 0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70, 0x289b7ec6, 0xeaa127fa,
61 0xd4ef3085, 0x04881d05, 0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
62 0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039, 0x655b59c3, 0x8f0ccc92,
63 0xffeff47d, 0x85845dd1, 0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
64 0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391
65 };
66
67 /** MD5 shift amounts */
68 static const uint8_t r[4][4] = {
69 { 7, 12, 17, 22 },
70 { 5, 9, 14, 20 },
71 { 4, 11, 16, 23 },
72 { 6, 10, 15, 21 },
73 };
74
75 /**
76 * f(b,c,d) for steps 0 to 15
77 *
78 * @v v MD5 variables
79 * @ret f f(b,c,d)
80 */
81 static uint32_t md5_f_0_15 ( struct md5_variables *v ) {
82 return ( v->d ^ ( v->b & ( v->c ^ v->d ) ) );
83 }
84
85 /**
86 * f(b,c,d) for steps 16 to 31
87 *
88 * @v v MD5 variables
89 * @ret f f(b,c,d)
90 */
91 static uint32_t md5_f_16_31 ( struct md5_variables *v ) {
92 return ( v->c ^ ( v->d & ( v->b ^ v->c ) ) );
93 }
94
95 /**
96 * f(b,c,d) for steps 32 to 47
97 *
98 * @v v MD5 variables
99 * @ret f f(b,c,d)
100 */
101 static uint32_t md5_f_32_47 ( struct md5_variables *v ) {
102 return ( v->b ^ v->c ^ v->d );
103 }
104
105 /**
106 * f(b,c,d) for steps 48 to 63
107 *
108 * @v v MD5 variables
109 * @ret f f(b,c,d)
110 */
111 static uint32_t md5_f_48_63 ( struct md5_variables *v ) {
112 return ( v->c ^ ( v->b | (~v->d) ) );
113 }
114
115 /** An MD5 step function */
116 struct md5_step {
117 /**
118 * Calculate f(b,c,d)
119 *
120 * @v v MD5 variables
121 * @ret f f(b,c,d)
122 */
123 uint32_t ( * f ) ( struct md5_variables *v );
124 /** Coefficient of i in g=ni+m */
125 uint8_t coefficient;
126 /** Constant term in g=ni+m */
127 uint8_t constant;
128 };
129
130 /** MD5 steps */
131 static struct md5_step md5_steps[4] = {
132 /** 0 to 15 */
133 { .f = md5_f_0_15, .coefficient = 1, .constant = 0 },
134 /** 16 to 31 */
135 { .f = md5_f_16_31, .coefficient = 5, .constant = 1 },
136 /** 32 to 47 */
137 { .f = md5_f_32_47, .coefficient = 3, .constant = 5 },
138 /** 48 to 63 */
139 { .f = md5_f_48_63, .coefficient = 7, .constant = 0 },
140 };
141
142 /**
143 * Initialise MD5 algorithm
144 *
145 * @v ctx MD5 context
146 */
147 static void md5_init ( void *ctx ) {
148 struct md5_context *context = ctx;
149
150 context->ddd.dd.digest.h[0] = cpu_to_le32 ( 0x67452301 );
151 context->ddd.dd.digest.h[1] = cpu_to_le32 ( 0xefcdab89 );
152 context->ddd.dd.digest.h[2] = cpu_to_le32 ( 0x98badcfe );
153 context->ddd.dd.digest.h[3] = cpu_to_le32 ( 0x10325476 );
154 context->len = 0;
155 }
156
157 /**
158 * Calculate MD5 digest of accumulated data
159 *
160 * @v context MD5 context
161 */
162 static void md5_digest ( struct md5_context *context ) {
163 union {
164 union md5_digest_data_dwords ddd;
165 struct md5_variables v;
166 } u;
167 uint32_t *a = &u.v.a;
168 uint32_t *b = &u.v.b;
169 uint32_t *c = &u.v.c;
170 uint32_t *d = &u.v.d;
171 uint32_t *w = u.v.w;
172 uint32_t f;
173 uint32_t g;
174 uint32_t temp;
175 struct md5_step *step;
176 unsigned int round;
177 unsigned int i;
178
179 /* Sanity checks */
180 assert ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 );
181 linker_assert ( &u.ddd.dd.digest.h[0] == a, md5_bad_layout );
182 linker_assert ( &u.ddd.dd.digest.h[1] == b, md5_bad_layout );
183 linker_assert ( &u.ddd.dd.digest.h[2] == c, md5_bad_layout );
184 linker_assert ( &u.ddd.dd.digest.h[3] == d, md5_bad_layout );
185 linker_assert ( &u.ddd.dd.data.dword[0] == w, md5_bad_layout );
186
187 DBGC ( context, "MD5 digesting:\n" );
188 DBGC_HDA ( context, 0, &context->ddd.dd.digest,
189 sizeof ( context->ddd.dd.digest ) );
190 DBGC_HDA ( context, context->len, &context->ddd.dd.data,
191 sizeof ( context->ddd.dd.data ) );
192
193 /* Convert h[0..3] to host-endian, and initialise a, b, c, d,
194 * and w[0..15]
195 */
196 for ( i = 0 ; i < ( sizeof ( u.ddd.dword ) /
197 sizeof ( u.ddd.dword[0] ) ) ; i++ ) {
198 le32_to_cpus ( &context->ddd.dword[i] );
199 u.ddd.dword[i] = context->ddd.dword[i];
200 }
201
202 /* Main loop */
203 for ( i = 0 ; i < 64 ; i++ ) {
204 round = ( i / 16 );
205 step = &md5_steps[round];
206 f = step->f ( &u.v );
207 g = ( ( ( step->coefficient * i ) + step->constant ) % 16 );
208 temp = *d;
209 *d = *c;
210 *c = *b;
211 *b = ( *b + rol32 ( ( *a + f + k[i] + w[g] ),
212 r[round][ i % 4 ] ) );
213 *a = temp;
214 DBGC2 ( context, "%2d : %08x %08x %08x %08x\n",
215 i, *a, *b, *c, *d );
216 }
217
218 /* Add chunk to hash and convert back to little-endian */
219 for ( i = 0 ; i < 4 ; i++ ) {
220 context->ddd.dd.digest.h[i] =
221 cpu_to_le32 ( context->ddd.dd.digest.h[i] +
222 u.ddd.dd.digest.h[i] );
223 }
224
225 DBGC ( context, "MD5 digested:\n" );
226 DBGC_HDA ( context, 0, &context->ddd.dd.digest,
227 sizeof ( context->ddd.dd.digest ) );
228 }
229
230 /**
231 * Accumulate data with MD5 algorithm
232 *
233 * @v ctx MD5 context
234 * @v data Data
235 * @v len Length of data
236 */
237 static void md5_update ( void *ctx, const void *data, size_t len ) {
238 struct md5_context *context = ctx;
239 const uint8_t *byte = data;
240 size_t offset;
241
242 /* Accumulate data a byte at a time, performing the digest
243 * whenever we fill the data buffer
244 */
245 while ( len-- ) {
246 offset = ( context->len % sizeof ( context->ddd.dd.data ) );
247 context->ddd.dd.data.byte[offset] = *(byte++);
248 context->len++;
249 if ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 )
250 md5_digest ( context );
251 }
252 }
253
254 /**
255 * Generate MD5 digest
256 *
257 * @v ctx MD5 context
258 * @v out Output buffer
259 */
260 static void md5_final ( void *ctx, void *out ) {
261 struct md5_context *context = ctx;
262 uint64_t len_bits;
263 uint8_t pad;
264
265 /* Record length before pre-processing */
266 len_bits = cpu_to_le64 ( ( ( uint64_t ) context->len ) * 8 );
267
268 /* Pad with a single "1" bit followed by as many "0" bits as required */
269 pad = 0x80;
270 do {
271 md5_update ( ctx, &pad, sizeof ( pad ) );
272 pad = 0x00;
273 } while ( ( context->len % sizeof ( context->ddd.dd.data ) ) !=
274 offsetof ( typeof ( context->ddd.dd.data ), final.len ) );
275
276 /* Append length (in bits) */
277 md5_update ( ctx, &len_bits, sizeof ( len_bits ) );
278 assert ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 );
279
280 /* Copy out final digest */
281 memcpy ( out, &context->ddd.dd.digest,
282 sizeof ( context->ddd.dd.digest ) );
283 }
284
285 /** MD5 algorithm */
286 struct digest_algorithm md5_algorithm = {
287 .name = "md5",
288 .ctxsize = sizeof ( struct md5_context ),
289 .blocksize = sizeof ( union md5_block ),
290 .digestsize = sizeof ( struct md5_digest ),
291 .init = md5_init,
292 .update = md5_update,
293 .final = md5_final,
294 };