xref: /openbmc/u-boot/lib/sha256.c (revision 8314bfe5)
1 /*
2  * FIPS-180-2 compliant SHA-256 implementation
3  *
4  * Copyright (C) 2001-2003  Christophe Devine
5  *
6  * SPDX-License-Identifier:	GPL-2.0+
7  */
8 
9 #ifndef USE_HOSTCC
10 #include <common.h>
11 #include <linux/string.h>
12 #else
13 #include <string.h>
14 #endif /* USE_HOSTCC */
15 #include <watchdog.h>
16 #include <u-boot/sha256.h>
17 
18 const uint8_t sha256_der_prefix[SHA256_DER_LEN] = {
19 	0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86,
20 	0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05,
21 	0x00, 0x04, 0x20
22 };
23 
24 /*
25  * 32-bit integer manipulation macros (big endian)
26  */
27 #ifndef GET_UINT32_BE
28 #define GET_UINT32_BE(n,b,i) {				\
29 	(n) = ( (unsigned long) (b)[(i)    ] << 24 )	\
30 	    | ( (unsigned long) (b)[(i) + 1] << 16 )	\
31 	    | ( (unsigned long) (b)[(i) + 2] <<  8 )	\
32 	    | ( (unsigned long) (b)[(i) + 3]       );	\
33 }
34 #endif
35 #ifndef PUT_UINT32_BE
36 #define PUT_UINT32_BE(n,b,i) {				\
37 	(b)[(i)    ] = (unsigned char) ( (n) >> 24 );	\
38 	(b)[(i) + 1] = (unsigned char) ( (n) >> 16 );	\
39 	(b)[(i) + 2] = (unsigned char) ( (n) >>  8 );	\
40 	(b)[(i) + 3] = (unsigned char) ( (n)       );	\
41 }
42 #endif
43 
44 void sha256_starts(sha256_context * ctx)
45 {
46 	ctx->total[0] = 0;
47 	ctx->total[1] = 0;
48 
49 	ctx->state[0] = 0x6A09E667;
50 	ctx->state[1] = 0xBB67AE85;
51 	ctx->state[2] = 0x3C6EF372;
52 	ctx->state[3] = 0xA54FF53A;
53 	ctx->state[4] = 0x510E527F;
54 	ctx->state[5] = 0x9B05688C;
55 	ctx->state[6] = 0x1F83D9AB;
56 	ctx->state[7] = 0x5BE0CD19;
57 }
58 
59 static void sha256_process(sha256_context *ctx, const uint8_t data[64])
60 {
61 	uint32_t temp1, temp2;
62 	uint32_t W[64];
63 	uint32_t A, B, C, D, E, F, G, H;
64 
65 	GET_UINT32_BE(W[0], data, 0);
66 	GET_UINT32_BE(W[1], data, 4);
67 	GET_UINT32_BE(W[2], data, 8);
68 	GET_UINT32_BE(W[3], data, 12);
69 	GET_UINT32_BE(W[4], data, 16);
70 	GET_UINT32_BE(W[5], data, 20);
71 	GET_UINT32_BE(W[6], data, 24);
72 	GET_UINT32_BE(W[7], data, 28);
73 	GET_UINT32_BE(W[8], data, 32);
74 	GET_UINT32_BE(W[9], data, 36);
75 	GET_UINT32_BE(W[10], data, 40);
76 	GET_UINT32_BE(W[11], data, 44);
77 	GET_UINT32_BE(W[12], data, 48);
78 	GET_UINT32_BE(W[13], data, 52);
79 	GET_UINT32_BE(W[14], data, 56);
80 	GET_UINT32_BE(W[15], data, 60);
81 
82 #define SHR(x,n) ((x & 0xFFFFFFFF) >> n)
83 #define ROTR(x,n) (SHR(x,n) | (x << (32 - n)))
84 
85 #define S0(x) (ROTR(x, 7) ^ ROTR(x,18) ^ SHR(x, 3))
86 #define S1(x) (ROTR(x,17) ^ ROTR(x,19) ^ SHR(x,10))
87 
88 #define S2(x) (ROTR(x, 2) ^ ROTR(x,13) ^ ROTR(x,22))
89 #define S3(x) (ROTR(x, 6) ^ ROTR(x,11) ^ ROTR(x,25))
90 
91 #define F0(x,y,z) ((x & y) | (z & (x | y)))
92 #define F1(x,y,z) (z ^ (x & (y ^ z)))
93 
94 #define R(t)					\
95 (						\
96 	W[t] = S1(W[t - 2]) + W[t - 7] +	\
97 		S0(W[t - 15]) + W[t - 16]	\
98 )
99 
100 #define P(a,b,c,d,e,f,g,h,x,K) {		\
101 	temp1 = h + S3(e) + F1(e,f,g) + K + x;	\
102 	temp2 = S2(a) + F0(a,b,c);		\
103 	d += temp1; h = temp1 + temp2;		\
104 }
105 
106 	A = ctx->state[0];
107 	B = ctx->state[1];
108 	C = ctx->state[2];
109 	D = ctx->state[3];
110 	E = ctx->state[4];
111 	F = ctx->state[5];
112 	G = ctx->state[6];
113 	H = ctx->state[7];
114 
115 	P(A, B, C, D, E, F, G, H, W[0], 0x428A2F98);
116 	P(H, A, B, C, D, E, F, G, W[1], 0x71374491);
117 	P(G, H, A, B, C, D, E, F, W[2], 0xB5C0FBCF);
118 	P(F, G, H, A, B, C, D, E, W[3], 0xE9B5DBA5);
119 	P(E, F, G, H, A, B, C, D, W[4], 0x3956C25B);
120 	P(D, E, F, G, H, A, B, C, W[5], 0x59F111F1);
121 	P(C, D, E, F, G, H, A, B, W[6], 0x923F82A4);
122 	P(B, C, D, E, F, G, H, A, W[7], 0xAB1C5ED5);
123 	P(A, B, C, D, E, F, G, H, W[8], 0xD807AA98);
124 	P(H, A, B, C, D, E, F, G, W[9], 0x12835B01);
125 	P(G, H, A, B, C, D, E, F, W[10], 0x243185BE);
126 	P(F, G, H, A, B, C, D, E, W[11], 0x550C7DC3);
127 	P(E, F, G, H, A, B, C, D, W[12], 0x72BE5D74);
128 	P(D, E, F, G, H, A, B, C, W[13], 0x80DEB1FE);
129 	P(C, D, E, F, G, H, A, B, W[14], 0x9BDC06A7);
130 	P(B, C, D, E, F, G, H, A, W[15], 0xC19BF174);
131 	P(A, B, C, D, E, F, G, H, R(16), 0xE49B69C1);
132 	P(H, A, B, C, D, E, F, G, R(17), 0xEFBE4786);
133 	P(G, H, A, B, C, D, E, F, R(18), 0x0FC19DC6);
134 	P(F, G, H, A, B, C, D, E, R(19), 0x240CA1CC);
135 	P(E, F, G, H, A, B, C, D, R(20), 0x2DE92C6F);
136 	P(D, E, F, G, H, A, B, C, R(21), 0x4A7484AA);
137 	P(C, D, E, F, G, H, A, B, R(22), 0x5CB0A9DC);
138 	P(B, C, D, E, F, G, H, A, R(23), 0x76F988DA);
139 	P(A, B, C, D, E, F, G, H, R(24), 0x983E5152);
140 	P(H, A, B, C, D, E, F, G, R(25), 0xA831C66D);
141 	P(G, H, A, B, C, D, E, F, R(26), 0xB00327C8);
142 	P(F, G, H, A, B, C, D, E, R(27), 0xBF597FC7);
143 	P(E, F, G, H, A, B, C, D, R(28), 0xC6E00BF3);
144 	P(D, E, F, G, H, A, B, C, R(29), 0xD5A79147);
145 	P(C, D, E, F, G, H, A, B, R(30), 0x06CA6351);
146 	P(B, C, D, E, F, G, H, A, R(31), 0x14292967);
147 	P(A, B, C, D, E, F, G, H, R(32), 0x27B70A85);
148 	P(H, A, B, C, D, E, F, G, R(33), 0x2E1B2138);
149 	P(G, H, A, B, C, D, E, F, R(34), 0x4D2C6DFC);
150 	P(F, G, H, A, B, C, D, E, R(35), 0x53380D13);
151 	P(E, F, G, H, A, B, C, D, R(36), 0x650A7354);
152 	P(D, E, F, G, H, A, B, C, R(37), 0x766A0ABB);
153 	P(C, D, E, F, G, H, A, B, R(38), 0x81C2C92E);
154 	P(B, C, D, E, F, G, H, A, R(39), 0x92722C85);
155 	P(A, B, C, D, E, F, G, H, R(40), 0xA2BFE8A1);
156 	P(H, A, B, C, D, E, F, G, R(41), 0xA81A664B);
157 	P(G, H, A, B, C, D, E, F, R(42), 0xC24B8B70);
158 	P(F, G, H, A, B, C, D, E, R(43), 0xC76C51A3);
159 	P(E, F, G, H, A, B, C, D, R(44), 0xD192E819);
160 	P(D, E, F, G, H, A, B, C, R(45), 0xD6990624);
161 	P(C, D, E, F, G, H, A, B, R(46), 0xF40E3585);
162 	P(B, C, D, E, F, G, H, A, R(47), 0x106AA070);
163 	P(A, B, C, D, E, F, G, H, R(48), 0x19A4C116);
164 	P(H, A, B, C, D, E, F, G, R(49), 0x1E376C08);
165 	P(G, H, A, B, C, D, E, F, R(50), 0x2748774C);
166 	P(F, G, H, A, B, C, D, E, R(51), 0x34B0BCB5);
167 	P(E, F, G, H, A, B, C, D, R(52), 0x391C0CB3);
168 	P(D, E, F, G, H, A, B, C, R(53), 0x4ED8AA4A);
169 	P(C, D, E, F, G, H, A, B, R(54), 0x5B9CCA4F);
170 	P(B, C, D, E, F, G, H, A, R(55), 0x682E6FF3);
171 	P(A, B, C, D, E, F, G, H, R(56), 0x748F82EE);
172 	P(H, A, B, C, D, E, F, G, R(57), 0x78A5636F);
173 	P(G, H, A, B, C, D, E, F, R(58), 0x84C87814);
174 	P(F, G, H, A, B, C, D, E, R(59), 0x8CC70208);
175 	P(E, F, G, H, A, B, C, D, R(60), 0x90BEFFFA);
176 	P(D, E, F, G, H, A, B, C, R(61), 0xA4506CEB);
177 	P(C, D, E, F, G, H, A, B, R(62), 0xBEF9A3F7);
178 	P(B, C, D, E, F, G, H, A, R(63), 0xC67178F2);
179 
180 	ctx->state[0] += A;
181 	ctx->state[1] += B;
182 	ctx->state[2] += C;
183 	ctx->state[3] += D;
184 	ctx->state[4] += E;
185 	ctx->state[5] += F;
186 	ctx->state[6] += G;
187 	ctx->state[7] += H;
188 }
189 
190 void sha256_update(sha256_context *ctx, const uint8_t *input, uint32_t length)
191 {
192 	uint32_t left, fill;
193 
194 	if (!length)
195 		return;
196 
197 	left = ctx->total[0] & 0x3F;
198 	fill = 64 - left;
199 
200 	ctx->total[0] += length;
201 	ctx->total[0] &= 0xFFFFFFFF;
202 
203 	if (ctx->total[0] < length)
204 		ctx->total[1]++;
205 
206 	if (left && length >= fill) {
207 		memcpy((void *) (ctx->buffer + left), (void *) input, fill);
208 		sha256_process(ctx, ctx->buffer);
209 		length -= fill;
210 		input += fill;
211 		left = 0;
212 	}
213 
214 	while (length >= 64) {
215 		sha256_process(ctx, input);
216 		length -= 64;
217 		input += 64;
218 	}
219 
220 	if (length)
221 		memcpy((void *) (ctx->buffer + left), (void *) input, length);
222 }
223 
224 static uint8_t sha256_padding[64] = {
225 	0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
226 	   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
227 	   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
228 	   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
229 };
230 
231 void sha256_finish(sha256_context * ctx, uint8_t digest[32])
232 {
233 	uint32_t last, padn;
234 	uint32_t high, low;
235 	uint8_t msglen[8];
236 
237 	high = ((ctx->total[0] >> 29)
238 		| (ctx->total[1] << 3));
239 	low = (ctx->total[0] << 3);
240 
241 	PUT_UINT32_BE(high, msglen, 0);
242 	PUT_UINT32_BE(low, msglen, 4);
243 
244 	last = ctx->total[0] & 0x3F;
245 	padn = (last < 56) ? (56 - last) : (120 - last);
246 
247 	sha256_update(ctx, sha256_padding, padn);
248 	sha256_update(ctx, msglen, 8);
249 
250 	PUT_UINT32_BE(ctx->state[0], digest, 0);
251 	PUT_UINT32_BE(ctx->state[1], digest, 4);
252 	PUT_UINT32_BE(ctx->state[2], digest, 8);
253 	PUT_UINT32_BE(ctx->state[3], digest, 12);
254 	PUT_UINT32_BE(ctx->state[4], digest, 16);
255 	PUT_UINT32_BE(ctx->state[5], digest, 20);
256 	PUT_UINT32_BE(ctx->state[6], digest, 24);
257 	PUT_UINT32_BE(ctx->state[7], digest, 28);
258 }
259 
260 /*
261  * Output = SHA-256( input buffer ). Trigger the watchdog every 'chunk_sz'
262  * bytes of input processed.
263  */
264 void sha256_csum_wd(const unsigned char *input, unsigned int ilen,
265 		unsigned char *output, unsigned int chunk_sz)
266 {
267 	sha256_context ctx;
268 #if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
269 	const unsigned char *end;
270 	unsigned char *curr;
271 	int chunk;
272 #endif
273 
274 	sha256_starts(&ctx);
275 
276 #if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
277 	curr = (unsigned char *)input;
278 	end = input + ilen;
279 	while (curr < end) {
280 		chunk = end - curr;
281 		if (chunk > chunk_sz)
282 			chunk = chunk_sz;
283 		sha256_update(&ctx, curr, chunk);
284 		curr += chunk;
285 		WATCHDOG_RESET();
286 	}
287 #else
288 	sha256_update(&ctx, input, ilen);
289 #endif
290 
291 	sha256_finish(&ctx, output);
292 }
293