1 /*
2  * SHA-256, as specified in
3  * http://csrc.nist.gov/groups/STM/cavp/documents/shs/sha256-384-512.pdf
4  *
5  * SHA-256 code by Jean-Luc Cooke <jlcooke@certainkey.com>.
6  *
7  * Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
8  * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
9  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
10  * Copyright (c) 2014 Red Hat Inc.
11  *
12  * This program is free software; you can redistribute it and/or modify it
13  * under the terms of the GNU General Public License as published by the Free
14  * Software Foundation; either version 2 of the License, or (at your option)
15  * any later version.
16  */
17 
18 #include <linux/bitops.h>
19 #include <linux/sha256.h>
20 #include <linux/string.h>
21 #include <asm/byteorder.h>
22 
Ch(u32 x,u32 y,u32 z)23 static inline u32 Ch(u32 x, u32 y, u32 z)
24 {
25 	return z ^ (x & (y ^ z));
26 }
27 
Maj(u32 x,u32 y,u32 z)28 static inline u32 Maj(u32 x, u32 y, u32 z)
29 {
30 	return (x & y) | (z & (x | y));
31 }
32 
33 #define e0(x)       (ror32(x, 2) ^ ror32(x, 13) ^ ror32(x, 22))
34 #define e1(x)       (ror32(x, 6) ^ ror32(x, 11) ^ ror32(x, 25))
35 #define s0(x)       (ror32(x, 7) ^ ror32(x, 18) ^ (x >> 3))
36 #define s1(x)       (ror32(x, 17) ^ ror32(x, 19) ^ (x >> 10))
37 
LOAD_OP(int I,u32 * W,const u8 * input)38 static inline void LOAD_OP(int I, u32 *W, const u8 *input)
39 {
40 	W[I] = __be32_to_cpu(((__be32 *)(input))[I]);
41 }
42 
BLEND_OP(int I,u32 * W)43 static inline void BLEND_OP(int I, u32 *W)
44 {
45 	W[I] = s1(W[I-2]) + W[I-7] + s0(W[I-15]) + W[I-16];
46 }
47 
sha256_transform(u32 * state,const u8 * input)48 static void sha256_transform(u32 *state, const u8 *input)
49 {
50 	u32 a, b, c, d, e, f, g, h, t1, t2;
51 	u32 W[64];
52 	int i;
53 
54 	/* load the input */
55 	for (i = 0; i < 16; i++)
56 		LOAD_OP(i, W, input);
57 
58 	/* now blend */
59 	for (i = 16; i < 64; i++)
60 		BLEND_OP(i, W);
61 
62 	/* load the state into our registers */
63 	a = state[0];  b = state[1];  c = state[2];  d = state[3];
64 	e = state[4];  f = state[5];  g = state[6];  h = state[7];
65 
66 	/* now iterate */
67 	t1 = h + e1(e) + Ch(e, f, g) + 0x428a2f98 + W[0];
68 	t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1 + t2;
69 	t1 = g + e1(d) + Ch(d, e, f) + 0x71374491 + W[1];
70 	t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1 + t2;
71 	t1 = f + e1(c) + Ch(c, d, e) + 0xb5c0fbcf + W[2];
72 	t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1 + t2;
73 	t1 = e + e1(b) + Ch(b, c, d) + 0xe9b5dba5 + W[3];
74 	t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1 + t2;
75 	t1 = d + e1(a) + Ch(a, b, c) + 0x3956c25b + W[4];
76 	t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1 + t2;
77 	t1 = c + e1(h) + Ch(h, a, b) + 0x59f111f1 + W[5];
78 	t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1 + t2;
79 	t1 = b + e1(g) + Ch(g, h, a) + 0x923f82a4 + W[6];
80 	t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1 + t2;
81 	t1 = a + e1(f) + Ch(f, g, h) + 0xab1c5ed5 + W[7];
82 	t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1 + t2;
83 
84 	t1 = h + e1(e) + Ch(e, f, g) + 0xd807aa98 + W[8];
85 	t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1 + t2;
86 	t1 = g + e1(d) + Ch(d, e, f) + 0x12835b01 + W[9];
87 	t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1 + t2;
88 	t1 = f + e1(c) + Ch(c, d, e) + 0x243185be + W[10];
89 	t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1 + t2;
90 	t1 = e + e1(b) + Ch(b, c, d) + 0x550c7dc3 + W[11];
91 	t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1 + t2;
92 	t1 = d + e1(a) + Ch(a, b, c) + 0x72be5d74 + W[12];
93 	t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1 + t2;
94 	t1 = c + e1(h) + Ch(h, a, b) + 0x80deb1fe + W[13];
95 	t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1 + t2;
96 	t1 = b + e1(g) + Ch(g, h, a) + 0x9bdc06a7 + W[14];
97 	t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1 + t2;
98 	t1 = a + e1(f) + Ch(f, g, h) + 0xc19bf174 + W[15];
99 	t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1+t2;
100 
101 	t1 = h + e1(e) + Ch(e, f, g) + 0xe49b69c1 + W[16];
102 	t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1+t2;
103 	t1 = g + e1(d) + Ch(d, e, f) + 0xefbe4786 + W[17];
104 	t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1+t2;
105 	t1 = f + e1(c) + Ch(c, d, e) + 0x0fc19dc6 + W[18];
106 	t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1+t2;
107 	t1 = e + e1(b) + Ch(b, c, d) + 0x240ca1cc + W[19];
108 	t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1+t2;
109 	t1 = d + e1(a) + Ch(a, b, c) + 0x2de92c6f + W[20];
110 	t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1+t2;
111 	t1 = c + e1(h) + Ch(h, a, b) + 0x4a7484aa + W[21];
112 	t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1+t2;
113 	t1 = b + e1(g) + Ch(g, h, a) + 0x5cb0a9dc + W[22];
114 	t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1+t2;
115 	t1 = a + e1(f) + Ch(f, g, h) + 0x76f988da + W[23];
116 	t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1+t2;
117 
118 	t1 = h + e1(e) + Ch(e, f, g) + 0x983e5152 + W[24];
119 	t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1+t2;
120 	t1 = g + e1(d) + Ch(d, e, f) + 0xa831c66d + W[25];
121 	t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1+t2;
122 	t1 = f + e1(c) + Ch(c, d, e) + 0xb00327c8 + W[26];
123 	t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1+t2;
124 	t1 = e + e1(b) + Ch(b, c, d) + 0xbf597fc7 + W[27];
125 	t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1+t2;
126 	t1 = d + e1(a) + Ch(a, b, c) + 0xc6e00bf3 + W[28];
127 	t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1+t2;
128 	t1 = c + e1(h) + Ch(h, a, b) + 0xd5a79147 + W[29];
129 	t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1+t2;
130 	t1 = b + e1(g) + Ch(g, h, a) + 0x06ca6351 + W[30];
131 	t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1+t2;
132 	t1 = a + e1(f) + Ch(f, g, h) + 0x14292967 + W[31];
133 	t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1+t2;
134 
135 	t1 = h + e1(e) + Ch(e, f, g) + 0x27b70a85 + W[32];
136 	t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1+t2;
137 	t1 = g + e1(d) + Ch(d, e, f) + 0x2e1b2138 + W[33];
138 	t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1+t2;
139 	t1 = f + e1(c) + Ch(c, d, e) + 0x4d2c6dfc + W[34];
140 	t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1+t2;
141 	t1 = e + e1(b) + Ch(b, c, d) + 0x53380d13 + W[35];
142 	t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1+t2;
143 	t1 = d + e1(a) + Ch(a, b, c) + 0x650a7354 + W[36];
144 	t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1+t2;
145 	t1 = c + e1(h) + Ch(h, a, b) + 0x766a0abb + W[37];
146 	t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1+t2;
147 	t1 = b + e1(g) + Ch(g, h, a) + 0x81c2c92e + W[38];
148 	t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1+t2;
149 	t1 = a + e1(f) + Ch(f, g, h) + 0x92722c85 + W[39];
150 	t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1+t2;
151 
152 	t1 = h + e1(e) + Ch(e, f, g) + 0xa2bfe8a1 + W[40];
153 	t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1+t2;
154 	t1 = g + e1(d) + Ch(d, e, f) + 0xa81a664b + W[41];
155 	t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1+t2;
156 	t1 = f + e1(c) + Ch(c, d, e) + 0xc24b8b70 + W[42];
157 	t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1+t2;
158 	t1 = e + e1(b) + Ch(b, c, d) + 0xc76c51a3 + W[43];
159 	t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1+t2;
160 	t1 = d + e1(a) + Ch(a, b, c) + 0xd192e819 + W[44];
161 	t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1+t2;
162 	t1 = c + e1(h) + Ch(h, a, b) + 0xd6990624 + W[45];
163 	t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1+t2;
164 	t1 = b + e1(g) + Ch(g, h, a) + 0xf40e3585 + W[46];
165 	t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1+t2;
166 	t1 = a + e1(f) + Ch(f, g, h) + 0x106aa070 + W[47];
167 	t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1+t2;
168 
169 	t1 = h + e1(e) + Ch(e, f, g) + 0x19a4c116 + W[48];
170 	t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1+t2;
171 	t1 = g + e1(d) + Ch(d, e, f) + 0x1e376c08 + W[49];
172 	t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1+t2;
173 	t1 = f + e1(c) + Ch(c, d, e) + 0x2748774c + W[50];
174 	t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1+t2;
175 	t1 = e + e1(b) + Ch(b, c, d) + 0x34b0bcb5 + W[51];
176 	t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1+t2;
177 	t1 = d + e1(a) + Ch(a, b, c) + 0x391c0cb3 + W[52];
178 	t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1+t2;
179 	t1 = c + e1(h) + Ch(h, a, b) + 0x4ed8aa4a + W[53];
180 	t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1+t2;
181 	t1 = b + e1(g) + Ch(g, h, a) + 0x5b9cca4f + W[54];
182 	t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1+t2;
183 	t1 = a + e1(f) + Ch(f, g, h) + 0x682e6ff3 + W[55];
184 	t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1+t2;
185 
186 	t1 = h + e1(e) + Ch(e, f, g) + 0x748f82ee + W[56];
187 	t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1+t2;
188 	t1 = g + e1(d) + Ch(d, e, f) + 0x78a5636f + W[57];
189 	t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1+t2;
190 	t1 = f + e1(c) + Ch(c, d, e) + 0x84c87814 + W[58];
191 	t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1+t2;
192 	t1 = e + e1(b) + Ch(b, c, d) + 0x8cc70208 + W[59];
193 	t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1+t2;
194 	t1 = d + e1(a) + Ch(a, b, c) + 0x90befffa + W[60];
195 	t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1+t2;
196 	t1 = c + e1(h) + Ch(h, a, b) + 0xa4506ceb + W[61];
197 	t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1+t2;
198 	t1 = b + e1(g) + Ch(g, h, a) + 0xbef9a3f7 + W[62];
199 	t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1+t2;
200 	t1 = a + e1(f) + Ch(f, g, h) + 0xc67178f2 + W[63];
201 	t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1+t2;
202 
203 	state[0] += a; state[1] += b; state[2] += c; state[3] += d;
204 	state[4] += e; state[5] += f; state[6] += g; state[7] += h;
205 
206 	/* clear any sensitive info... */
207 	a = b = c = d = e = f = g = h = t1 = t2 = 0;
208 	memset(W, 0, 64 * sizeof(u32));
209 }
210 
sha256_init(struct sha256_state * sctx)211 int sha256_init(struct sha256_state *sctx)
212 {
213 	sctx->state[0] = SHA256_H0;
214 	sctx->state[1] = SHA256_H1;
215 	sctx->state[2] = SHA256_H2;
216 	sctx->state[3] = SHA256_H3;
217 	sctx->state[4] = SHA256_H4;
218 	sctx->state[5] = SHA256_H5;
219 	sctx->state[6] = SHA256_H6;
220 	sctx->state[7] = SHA256_H7;
221 	sctx->count = 0;
222 
223 	return 0;
224 }
225 
sha256_update(struct sha256_state * sctx,const u8 * data,unsigned int len)226 int sha256_update(struct sha256_state *sctx, const u8 *data, unsigned int len)
227 {
228 	unsigned int partial, done;
229 	const u8 *src;
230 
231 	partial = sctx->count & 0x3f;
232 	sctx->count += len;
233 	done = 0;
234 	src = data;
235 
236 	if ((partial + len) > 63) {
237 		if (partial) {
238 			done = -partial;
239 			memcpy(sctx->buf + partial, data, done + 64);
240 			src = sctx->buf;
241 		}
242 
243 		do {
244 			sha256_transform(sctx->state, src);
245 			done += 64;
246 			src = data + done;
247 		} while (done + 63 < len);
248 
249 		partial = 0;
250 	}
251 	memcpy(sctx->buf + partial, src, len - done);
252 
253 	return 0;
254 }
255 
sha256_final(struct sha256_state * sctx,u8 * out)256 int sha256_final(struct sha256_state *sctx, u8 *out)
257 {
258 	__be32 *dst = (__be32 *)out;
259 	__be64 bits;
260 	unsigned int index, pad_len;
261 	int i;
262 	static const u8 padding[64] = { 0x80, };
263 
264 	/* Save number of bits */
265 	bits = cpu_to_be64(sctx->count << 3);
266 
267 	/* Pad out to 56 mod 64. */
268 	index = sctx->count & 0x3f;
269 	pad_len = (index < 56) ? (56 - index) : ((64+56) - index);
270 	sha256_update(sctx, padding, pad_len);
271 
272 	/* Append length (before padding) */
273 	sha256_update(sctx, (const u8 *)&bits, sizeof(bits));
274 
275 	/* Store state in digest */
276 	for (i = 0; i < 8; i++)
277 		dst[i] = cpu_to_be32(sctx->state[i]);
278 
279 	/* Zeroize sensitive information. */
280 	memset(sctx, 0, sizeof(*sctx));
281 
282 	return 0;
283 }
284