[fdt] Add ability to parse a MAC address from a flattened device tree
[ipxe.git] / src / crypto / sha256.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 * SHA-256 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/asn1.h>
39 #include <ipxe/sha256.h>
40
41 /** SHA-256 variables */
42 struct sha256_variables {
43 /* This layout matches that of struct sha256_digest_data,
44 * allowing for efficient endianness-conversion,
45 */
46 uint32_t a;
47 uint32_t b;
48 uint32_t c;
49 uint32_t d;
50 uint32_t e;
51 uint32_t f;
52 uint32_t g;
53 uint32_t h;
54 uint32_t w[SHA256_ROUNDS];
55 } __attribute__ (( packed ));
56
57 /** SHA-256 constants */
58 static const uint32_t k[SHA256_ROUNDS] = {
59 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1,
60 0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
61 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786,
62 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
63 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147,
64 0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
65 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b,
66 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
67 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a,
68 0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
69 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
70 };
71
72 /** SHA-256 initial digest values */
73 static const struct sha256_digest sha256_init_digest = {
74 .h = {
75 cpu_to_be32 ( 0x6a09e667 ),
76 cpu_to_be32 ( 0xbb67ae85 ),
77 cpu_to_be32 ( 0x3c6ef372 ),
78 cpu_to_be32 ( 0xa54ff53a ),
79 cpu_to_be32 ( 0x510e527f ),
80 cpu_to_be32 ( 0x9b05688c ),
81 cpu_to_be32 ( 0x1f83d9ab ),
82 cpu_to_be32 ( 0x5be0cd19 ),
83 },
84 };
85
86 /**
87 * Initialise SHA-256 family algorithm
88 *
89 * @v context SHA-256 context
90 * @v init Initial digest values
91 * @v digestsize Digest size
92 */
93 void sha256_family_init ( struct sha256_context *context,
94 const struct sha256_digest *init,
95 size_t digestsize ) {
96
97 context->len = 0;
98 context->digestsize = digestsize;
99 memcpy ( &context->ddd.dd.digest, init,
100 sizeof ( context->ddd.dd.digest ) );
101 }
102
103 /**
104 * Initialise SHA-256 algorithm
105 *
106 * @v ctx SHA-256 context
107 */
108 static void sha256_init ( void *ctx ) {
109 struct sha256_context *context = ctx;
110
111 sha256_family_init ( context, &sha256_init_digest,
112 sizeof ( struct sha256_digest ) );
113 }
114
115 /**
116 * Calculate SHA-256 digest of accumulated data
117 *
118 * @v context SHA-256 context
119 */
120 static void sha256_digest ( struct sha256_context *context ) {
121 union {
122 union sha256_digest_data_dwords ddd;
123 struct sha256_variables v;
124 } u;
125 uint32_t *a = &u.v.a;
126 uint32_t *b = &u.v.b;
127 uint32_t *c = &u.v.c;
128 uint32_t *d = &u.v.d;
129 uint32_t *e = &u.v.e;
130 uint32_t *f = &u.v.f;
131 uint32_t *g = &u.v.g;
132 uint32_t *h = &u.v.h;
133 uint32_t *w = u.v.w;
134 uint32_t s0;
135 uint32_t s1;
136 uint32_t maj;
137 uint32_t t1;
138 uint32_t t2;
139 uint32_t ch;
140 unsigned int i;
141
142 /* Sanity checks */
143 assert ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 );
144 linker_assert ( &u.ddd.dd.digest.h[0] == a, sha256_bad_layout );
145 linker_assert ( &u.ddd.dd.digest.h[1] == b, sha256_bad_layout );
146 linker_assert ( &u.ddd.dd.digest.h[2] == c, sha256_bad_layout );
147 linker_assert ( &u.ddd.dd.digest.h[3] == d, sha256_bad_layout );
148 linker_assert ( &u.ddd.dd.digest.h[4] == e, sha256_bad_layout );
149 linker_assert ( &u.ddd.dd.digest.h[5] == f, sha256_bad_layout );
150 linker_assert ( &u.ddd.dd.digest.h[6] == g, sha256_bad_layout );
151 linker_assert ( &u.ddd.dd.digest.h[7] == h, sha256_bad_layout );
152 linker_assert ( &u.ddd.dd.data.dword[0] == w, sha256_bad_layout );
153
154 DBGC ( context, "SHA256 digesting:\n" );
155 DBGC_HDA ( context, 0, &context->ddd.dd.digest,
156 sizeof ( context->ddd.dd.digest ) );
157 DBGC_HDA ( context, context->len, &context->ddd.dd.data,
158 sizeof ( context->ddd.dd.data ) );
159
160 /* Convert h[0..7] to host-endian, and initialise a, b, c, d,
161 * e, f, g, h, and w[0..15]
162 */
163 for ( i = 0 ; i < ( sizeof ( u.ddd.dword ) /
164 sizeof ( u.ddd.dword[0] ) ) ; i++ ) {
165 be32_to_cpus ( &context->ddd.dword[i] );
166 u.ddd.dword[i] = context->ddd.dword[i];
167 }
168
169 /* Initialise w[16..63] */
170 for ( i = 16 ; i < SHA256_ROUNDS ; i++ ) {
171 s0 = ( ror32 ( w[i-15], 7 ) ^ ror32 ( w[i-15], 18 ) ^
172 ( w[i-15] >> 3 ) );
173 s1 = ( ror32 ( w[i-2], 17 ) ^ ror32 ( w[i-2], 19 ) ^
174 ( w[i-2] >> 10 ) );
175 w[i] = ( w[i-16] + s0 + w[i-7] + s1 );
176 }
177
178 /* Main loop */
179 for ( i = 0 ; i < SHA256_ROUNDS ; i++ ) {
180 s0 = ( ror32 ( *a, 2 ) ^ ror32 ( *a, 13 ) ^ ror32 ( *a, 22 ) );
181 maj = ( ( *a & *b ) ^ ( *a & *c ) ^ ( *b & *c ) );
182 t2 = ( s0 + maj );
183 s1 = ( ror32 ( *e, 6 ) ^ ror32 ( *e, 11 ) ^ ror32 ( *e, 25 ) );
184 ch = ( ( *e & *f ) ^ ( (~*e) & *g ) );
185 t1 = ( *h + s1 + ch + k[i] + w[i] );
186 *h = *g;
187 *g = *f;
188 *f = *e;
189 *e = ( *d + t1 );
190 *d = *c;
191 *c = *b;
192 *b = *a;
193 *a = ( t1 + t2 );
194 DBGC2 ( context, "%2d : %08x %08x %08x %08x %08x %08x %08x "
195 "%08x\n", i, *a, *b, *c, *d, *e, *f, *g, *h );
196 }
197
198 /* Add chunk to hash and convert back to big-endian */
199 for ( i = 0 ; i < 8 ; i++ ) {
200 context->ddd.dd.digest.h[i] =
201 cpu_to_be32 ( context->ddd.dd.digest.h[i] +
202 u.ddd.dd.digest.h[i] );
203 }
204
205 DBGC ( context, "SHA256 digested:\n" );
206 DBGC_HDA ( context, 0, &context->ddd.dd.digest,
207 sizeof ( context->ddd.dd.digest ) );
208 }
209
210 /**
211 * Accumulate data with SHA-256 algorithm
212 *
213 * @v ctx SHA-256 context
214 * @v data Data
215 * @v len Length of data
216 */
217 void sha256_update ( void *ctx, const void *data, size_t len ) {
218 struct sha256_context *context = ctx;
219 const uint8_t *byte = data;
220 size_t offset;
221
222 /* Accumulate data a byte at a time, performing the digest
223 * whenever we fill the data buffer
224 */
225 while ( len-- ) {
226 offset = ( context->len % sizeof ( context->ddd.dd.data ) );
227 context->ddd.dd.data.byte[offset] = *(byte++);
228 context->len++;
229 if ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 )
230 sha256_digest ( context );
231 }
232 }
233
234 /**
235 * Generate SHA-256 digest
236 *
237 * @v ctx SHA-256 context
238 * @v out Output buffer
239 */
240 void sha256_final ( void *ctx, void *out ) {
241 struct sha256_context *context = ctx;
242 uint64_t len_bits;
243 uint8_t pad;
244
245 /* Record length before pre-processing */
246 len_bits = cpu_to_be64 ( ( ( uint64_t ) context->len ) * 8 );
247
248 /* Pad with a single "1" bit followed by as many "0" bits as required */
249 pad = 0x80;
250 do {
251 sha256_update ( ctx, &pad, sizeof ( pad ) );
252 pad = 0x00;
253 } while ( ( context->len % sizeof ( context->ddd.dd.data ) ) !=
254 offsetof ( typeof ( context->ddd.dd.data ), final.len ) );
255
256 /* Append length (in bits) */
257 sha256_update ( ctx, &len_bits, sizeof ( len_bits ) );
258 assert ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 );
259
260 /* Copy out final digest */
261 memcpy ( out, &context->ddd.dd.digest, context->digestsize );
262 }
263
264 /** SHA-256 algorithm */
265 struct digest_algorithm sha256_algorithm = {
266 .name = "sha256",
267 .ctxsize = sizeof ( struct sha256_context ),
268 .blocksize = sizeof ( union sha256_block ),
269 .digestsize = sizeof ( struct sha256_digest ),
270 .init = sha256_init,
271 .update = sha256_update,
272 .final = sha256_final,
273 };
274
275 /** "sha256" object identifier */
276 static uint8_t oid_sha256[] = { ASN1_OID_SHA256 };
277
278 /** "sha256" OID-identified algorithm */
279 struct asn1_algorithm oid_sha256_algorithm __asn1_algorithm = {
280 .name = "sha256",
281 .digest = &sha256_algorithm,
282 .oid = ASN1_OID_CURSOR ( oid_sha256 ),
283 };