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1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * SHA-256, as specified in
4  * http://csrc.nist.gov/groups/STM/cavp/documents/shs/sha256-384-512.pdf
5  *
6  * SHA-256 code by Jean-Luc Cooke <jlcooke@certainkey.com>.
7  *
8  * Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
9  * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
10  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
11  * Copyright (c) 2014 Red Hat Inc.
12  */
13 
14 #include <linux/bitops.h>
15 #include <linux/export.h>
16 #include <linux/module.h>
17 #include <linux/string.h>
18 #include <crypto/sha2.h>
19 #include <asm/unaligned.h>
20 #include <trace/hooks/fips140.h>
21 
22 static const u32 SHA256_K[] = {
23 	0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
24 	0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
25 	0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
26 	0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
27 	0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
28 	0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
29 	0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
30 	0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
31 	0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
32 	0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
33 	0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
34 	0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
35 	0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
36 	0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
37 	0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
38 	0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,
39 };
40 
Ch(u32 x,u32 y,u32 z)41 static inline u32 Ch(u32 x, u32 y, u32 z)
42 {
43 	return z ^ (x & (y ^ z));
44 }
45 
Maj(u32 x,u32 y,u32 z)46 static inline u32 Maj(u32 x, u32 y, u32 z)
47 {
48 	return (x & y) | (z & (x | y));
49 }
50 
51 #define e0(x)       (ror32(x, 2) ^ ror32(x, 13) ^ ror32(x, 22))
52 #define e1(x)       (ror32(x, 6) ^ ror32(x, 11) ^ ror32(x, 25))
53 #define s0(x)       (ror32(x, 7) ^ ror32(x, 18) ^ (x >> 3))
54 #define s1(x)       (ror32(x, 17) ^ ror32(x, 19) ^ (x >> 10))
55 
LOAD_OP(int I,u32 * W,const u8 * input)56 static inline void LOAD_OP(int I, u32 *W, const u8 *input)
57 {
58 	W[I] = get_unaligned_be32((__u32 *)input + I);
59 }
60 
BLEND_OP(int I,u32 * W)61 static inline void BLEND_OP(int I, u32 *W)
62 {
63 	W[I] = s1(W[I-2]) + W[I-7] + s0(W[I-15]) + W[I-16];
64 }
65 
66 #define SHA256_ROUND(i, a, b, c, d, e, f, g, h) do {		\
67 	u32 t1, t2;						\
68 	t1 = h + e1(e) + Ch(e, f, g) + SHA256_K[i] + W[i];	\
69 	t2 = e0(a) + Maj(a, b, c);				\
70 	d += t1;						\
71 	h = t1 + t2;						\
72 } while (0)
73 
sha256_transform(u32 * state,const u8 * input,u32 * W)74 static void sha256_transform(u32 *state, const u8 *input, u32 *W)
75 {
76 	u32 a, b, c, d, e, f, g, h;
77 	int i;
78 
79 	/* load the input */
80 	for (i = 0; i < 16; i += 8) {
81 		LOAD_OP(i + 0, W, input);
82 		LOAD_OP(i + 1, W, input);
83 		LOAD_OP(i + 2, W, input);
84 		LOAD_OP(i + 3, W, input);
85 		LOAD_OP(i + 4, W, input);
86 		LOAD_OP(i + 5, W, input);
87 		LOAD_OP(i + 6, W, input);
88 		LOAD_OP(i + 7, W, input);
89 	}
90 
91 	/* now blend */
92 	for (i = 16; i < 64; i += 8) {
93 		BLEND_OP(i + 0, W);
94 		BLEND_OP(i + 1, W);
95 		BLEND_OP(i + 2, W);
96 		BLEND_OP(i + 3, W);
97 		BLEND_OP(i + 4, W);
98 		BLEND_OP(i + 5, W);
99 		BLEND_OP(i + 6, W);
100 		BLEND_OP(i + 7, W);
101 	}
102 
103 	/* load the state into our registers */
104 	a = state[0];  b = state[1];  c = state[2];  d = state[3];
105 	e = state[4];  f = state[5];  g = state[6];  h = state[7];
106 
107 	/* now iterate */
108 	for (i = 0; i < 64; i += 8) {
109 		SHA256_ROUND(i + 0, a, b, c, d, e, f, g, h);
110 		SHA256_ROUND(i + 1, h, a, b, c, d, e, f, g);
111 		SHA256_ROUND(i + 2, g, h, a, b, c, d, e, f);
112 		SHA256_ROUND(i + 3, f, g, h, a, b, c, d, e);
113 		SHA256_ROUND(i + 4, e, f, g, h, a, b, c, d);
114 		SHA256_ROUND(i + 5, d, e, f, g, h, a, b, c);
115 		SHA256_ROUND(i + 6, c, d, e, f, g, h, a, b);
116 		SHA256_ROUND(i + 7, b, c, d, e, f, g, h, a);
117 	}
118 
119 	state[0] += a; state[1] += b; state[2] += c; state[3] += d;
120 	state[4] += e; state[5] += f; state[6] += g; state[7] += h;
121 }
122 
sha256_update(struct sha256_state * sctx,const u8 * data,unsigned int len)123 void sha256_update(struct sha256_state *sctx, const u8 *data, unsigned int len)
124 {
125 	unsigned int partial, done;
126 	const u8 *src;
127 	u32 W[64];
128 
129 	partial = sctx->count & 0x3f;
130 	sctx->count += len;
131 	done = 0;
132 	src = data;
133 
134 	if ((partial + len) > 63) {
135 		if (partial) {
136 			done = -partial;
137 			memcpy(sctx->buf + partial, data, done + 64);
138 			src = sctx->buf;
139 		}
140 
141 		do {
142 			sha256_transform(sctx->state, src, W);
143 			done += 64;
144 			src = data + done;
145 		} while (done + 63 < len);
146 
147 		memzero_explicit(W, sizeof(W));
148 
149 		partial = 0;
150 	}
151 	memcpy(sctx->buf + partial, src, len - done);
152 }
153 EXPORT_SYMBOL(sha256_update);
154 
sha224_update(struct sha256_state * sctx,const u8 * data,unsigned int len)155 void sha224_update(struct sha256_state *sctx, const u8 *data, unsigned int len)
156 {
157 	sha256_update(sctx, data, len);
158 }
159 EXPORT_SYMBOL(sha224_update);
160 
__sha256_final(struct sha256_state * sctx,u8 * out,int digest_words)161 static void __sha256_final(struct sha256_state *sctx, u8 *out, int digest_words)
162 {
163 	__be32 *dst = (__be32 *)out;
164 	__be64 bits;
165 	unsigned int index, pad_len;
166 	int i;
167 	static const u8 padding[64] = { 0x80, };
168 
169 	/* Save number of bits */
170 	bits = cpu_to_be64(sctx->count << 3);
171 
172 	/* Pad out to 56 mod 64. */
173 	index = sctx->count & 0x3f;
174 	pad_len = (index < 56) ? (56 - index) : ((64+56) - index);
175 	sha256_update(sctx, padding, pad_len);
176 
177 	/* Append length (before padding) */
178 	sha256_update(sctx, (const u8 *)&bits, sizeof(bits));
179 
180 	/* Store state in digest */
181 	for (i = 0; i < digest_words; i++)
182 		put_unaligned_be32(sctx->state[i], &dst[i]);
183 
184 	/* Zeroize sensitive information. */
185 	memzero_explicit(sctx, sizeof(*sctx));
186 }
187 
sha256_final(struct sha256_state * sctx,u8 * out)188 void sha256_final(struct sha256_state *sctx, u8 *out)
189 {
190 	__sha256_final(sctx, out, 8);
191 }
192 EXPORT_SYMBOL(sha256_final);
193 
sha224_final(struct sha256_state * sctx,u8 * out)194 void sha224_final(struct sha256_state *sctx, u8 *out)
195 {
196 	__sha256_final(sctx, out, 7);
197 }
198 EXPORT_SYMBOL(sha224_final);
199 
sha256(const u8 * data,unsigned int len,u8 * out)200 void sha256(const u8 *data, unsigned int len, u8 *out)
201 {
202 	struct sha256_state sctx;
203 
204 #if defined(CONFIG_CRYPTO_FIPS140) && !defined(BUILD_FIPS140_KO)
205 	int hook_inuse = 0;
206 
207 	trace_android_vh_sha256(data, len, out, &hook_inuse);
208 	if (hook_inuse)
209 		return;
210 #endif
211 
212 	sha256_init(&sctx);
213 	sha256_update(&sctx, data, len);
214 	sha256_final(&sctx, out);
215 }
216 EXPORT_SYMBOL(sha256);
217 
218 MODULE_LICENSE("GPL");
219