1 // SPDX-License-Identifier: GPL-2.0 1 // SPDX-License-Identifier: GPL-2.0
2 /* 2 /*
3 * NHPoly1305 - ε-almost-∆-universal hash f 3 * NHPoly1305 - ε-almost-∆-universal hash function for Adiantum
4 * 4 *
5 * Copyright 2018 Google LLC 5 * Copyright 2018 Google LLC
6 */ 6 */
7 7
8 /* 8 /*
9 * "NHPoly1305" is the main component of Adian 9 * "NHPoly1305" is the main component of Adiantum hashing.
10 * Specifically, it is the calculation 10 * Specifically, it is the calculation
11 * 11 *
12 * H_L ← Poly1305_{K_L}(NH_{K_N}(pad_{1 12 * H_L ← Poly1305_{K_L}(NH_{K_N}(pad_{128}(L)))
13 * 13 *
14 * from the procedure in section 6.4 of the Ad 14 * from the procedure in section 6.4 of the Adiantum paper [1]. It is an
15 * ε-almost-∆-universal (ε-∆U) hash func 15 * ε-almost-∆-universal (ε-∆U) hash function for equal-length inputs over
16 * Z/(2^{128}Z), where the "∆" operation is 16 * Z/(2^{128}Z), where the "∆" operation is addition. It hashes 1024-byte
17 * chunks of the input with the NH hash functi 17 * chunks of the input with the NH hash function [2], reducing the input length
18 * by 32x. The resulting NH digests are evalu 18 * by 32x. The resulting NH digests are evaluated as a polynomial in
19 * GF(2^{130}-5), like in the Poly1305 MAC [3] 19 * GF(2^{130}-5), like in the Poly1305 MAC [3]. Note that the polynomial
20 * evaluation by itself would suffice to achie 20 * evaluation by itself would suffice to achieve the ε-∆U property; NH is used
21 * for performance since it's over twice as fa 21 * for performance since it's over twice as fast as Poly1305.
22 * 22 *
23 * This is *not* a cryptographic hash function 23 * This is *not* a cryptographic hash function; do not use it as such!
24 * 24 *
25 * [1] Adiantum: length-preserving encryption 25 * [1] Adiantum: length-preserving encryption for entry-level processors
26 * (https://eprint.iacr.org/2018/720.pdf) 26 * (https://eprint.iacr.org/2018/720.pdf)
27 * [2] UMAC: Fast and Secure Message Authentic 27 * [2] UMAC: Fast and Secure Message Authentication
28 * (https://fastcrypto.org/umac/umac_proc. 28 * (https://fastcrypto.org/umac/umac_proc.pdf)
29 * [3] The Poly1305-AES message-authentication 29 * [3] The Poly1305-AES message-authentication code
30 * (https://cr.yp.to/mac/poly1305-20050329 30 * (https://cr.yp.to/mac/poly1305-20050329.pdf)
31 */ 31 */
32 32
33 #include <asm/unaligned.h> 33 #include <asm/unaligned.h>
34 #include <crypto/algapi.h> 34 #include <crypto/algapi.h>
35 #include <crypto/internal/hash.h> 35 #include <crypto/internal/hash.h>
36 #include <crypto/internal/poly1305.h> 36 #include <crypto/internal/poly1305.h>
37 #include <crypto/nhpoly1305.h> 37 #include <crypto/nhpoly1305.h>
38 #include <linux/crypto.h> 38 #include <linux/crypto.h>
39 #include <linux/kernel.h> 39 #include <linux/kernel.h>
40 #include <linux/module.h> 40 #include <linux/module.h>
41 41
42 static void nh_generic(const u32 *key, const u 42 static void nh_generic(const u32 *key, const u8 *message, size_t message_len,
43 __le64 hash[NH_NUM_PASS 43 __le64 hash[NH_NUM_PASSES])
44 { 44 {
45 u64 sums[4] = { 0, 0, 0, 0 }; 45 u64 sums[4] = { 0, 0, 0, 0 };
46 46
47 BUILD_BUG_ON(NH_PAIR_STRIDE != 2); 47 BUILD_BUG_ON(NH_PAIR_STRIDE != 2);
48 BUILD_BUG_ON(NH_NUM_PASSES != 4); 48 BUILD_BUG_ON(NH_NUM_PASSES != 4);
49 49
50 while (message_len) { 50 while (message_len) {
51 u32 m0 = get_unaligned_le32(me 51 u32 m0 = get_unaligned_le32(message + 0);
52 u32 m1 = get_unaligned_le32(me 52 u32 m1 = get_unaligned_le32(message + 4);
53 u32 m2 = get_unaligned_le32(me 53 u32 m2 = get_unaligned_le32(message + 8);
54 u32 m3 = get_unaligned_le32(me 54 u32 m3 = get_unaligned_le32(message + 12);
55 55
56 sums[0] += (u64)(u32)(m0 + key 56 sums[0] += (u64)(u32)(m0 + key[ 0]) * (u32)(m2 + key[ 2]);
57 sums[1] += (u64)(u32)(m0 + key 57 sums[1] += (u64)(u32)(m0 + key[ 4]) * (u32)(m2 + key[ 6]);
58 sums[2] += (u64)(u32)(m0 + key 58 sums[2] += (u64)(u32)(m0 + key[ 8]) * (u32)(m2 + key[10]);
59 sums[3] += (u64)(u32)(m0 + key 59 sums[3] += (u64)(u32)(m0 + key[12]) * (u32)(m2 + key[14]);
60 sums[0] += (u64)(u32)(m1 + key 60 sums[0] += (u64)(u32)(m1 + key[ 1]) * (u32)(m3 + key[ 3]);
61 sums[1] += (u64)(u32)(m1 + key 61 sums[1] += (u64)(u32)(m1 + key[ 5]) * (u32)(m3 + key[ 7]);
62 sums[2] += (u64)(u32)(m1 + key 62 sums[2] += (u64)(u32)(m1 + key[ 9]) * (u32)(m3 + key[11]);
63 sums[3] += (u64)(u32)(m1 + key 63 sums[3] += (u64)(u32)(m1 + key[13]) * (u32)(m3 + key[15]);
64 key += NH_MESSAGE_UNIT / sizeo 64 key += NH_MESSAGE_UNIT / sizeof(key[0]);
65 message += NH_MESSAGE_UNIT; 65 message += NH_MESSAGE_UNIT;
66 message_len -= NH_MESSAGE_UNIT 66 message_len -= NH_MESSAGE_UNIT;
67 } 67 }
68 68
69 hash[0] = cpu_to_le64(sums[0]); 69 hash[0] = cpu_to_le64(sums[0]);
70 hash[1] = cpu_to_le64(sums[1]); 70 hash[1] = cpu_to_le64(sums[1]);
71 hash[2] = cpu_to_le64(sums[2]); 71 hash[2] = cpu_to_le64(sums[2]);
72 hash[3] = cpu_to_le64(sums[3]); 72 hash[3] = cpu_to_le64(sums[3]);
73 } 73 }
74 74
75 /* Pass the next NH hash value through Poly130 75 /* Pass the next NH hash value through Poly1305 */
76 static void process_nh_hash_value(struct nhpol 76 static void process_nh_hash_value(struct nhpoly1305_state *state,
77 const struct 77 const struct nhpoly1305_key *key)
78 { 78 {
79 BUILD_BUG_ON(NH_HASH_BYTES % POLY1305_ 79 BUILD_BUG_ON(NH_HASH_BYTES % POLY1305_BLOCK_SIZE != 0);
80 80
81 poly1305_core_blocks(&state->poly_stat 81 poly1305_core_blocks(&state->poly_state, &key->poly_key, state->nh_hash,
82 NH_HASH_BYTES / P 82 NH_HASH_BYTES / POLY1305_BLOCK_SIZE, 1);
83 } 83 }
84 84
85 /* 85 /*
86 * Feed the next portion of the source data, a 86 * Feed the next portion of the source data, as a whole number of 16-byte
87 * "NH message units", through NH and Poly1305 87 * "NH message units", through NH and Poly1305. Each NH hash is taken over
88 * 1024 bytes, except possibly the final one w 88 * 1024 bytes, except possibly the final one which is taken over a multiple of
89 * 16 bytes up to 1024. Also, in the case whe 89 * 16 bytes up to 1024. Also, in the case where data is passed in misaligned
90 * chunks, we combine partial hashes; the end 90 * chunks, we combine partial hashes; the end result is the same either way.
91 */ 91 */
92 static void nhpoly1305_units(struct nhpoly1305 92 static void nhpoly1305_units(struct nhpoly1305_state *state,
93 const struct nhpo 93 const struct nhpoly1305_key *key,
94 const u8 *src, un 94 const u8 *src, unsigned int srclen, nh_t nh_fn)
95 { 95 {
96 do { 96 do {
97 unsigned int bytes; 97 unsigned int bytes;
98 98
99 if (state->nh_remaining == 0) 99 if (state->nh_remaining == 0) {
100 /* Starting a new NH m 100 /* Starting a new NH message */
101 bytes = min_t(unsigned 101 bytes = min_t(unsigned int, srclen, NH_MESSAGE_BYTES);
102 nh_fn(key->nh_key, src 102 nh_fn(key->nh_key, src, bytes, state->nh_hash);
103 state->nh_remaining = 103 state->nh_remaining = NH_MESSAGE_BYTES - bytes;
104 } else { 104 } else {
105 /* Continuing a previo 105 /* Continuing a previous NH message */
106 __le64 tmp_hash[NH_NUM 106 __le64 tmp_hash[NH_NUM_PASSES];
107 unsigned int pos; 107 unsigned int pos;
108 int i; 108 int i;
109 109
110 pos = NH_MESSAGE_BYTES 110 pos = NH_MESSAGE_BYTES - state->nh_remaining;
111 bytes = min(srclen, st 111 bytes = min(srclen, state->nh_remaining);
112 nh_fn(&key->nh_key[pos 112 nh_fn(&key->nh_key[pos / 4], src, bytes, tmp_hash);
113 for (i = 0; i < NH_NUM 113 for (i = 0; i < NH_NUM_PASSES; i++)
114 le64_add_cpu(& 114 le64_add_cpu(&state->nh_hash[i],
115 l 115 le64_to_cpu(tmp_hash[i]));
116 state->nh_remaining -= 116 state->nh_remaining -= bytes;
117 } 117 }
118 if (state->nh_remaining == 0) 118 if (state->nh_remaining == 0)
119 process_nh_hash_value( 119 process_nh_hash_value(state, key);
120 src += bytes; 120 src += bytes;
121 srclen -= bytes; 121 srclen -= bytes;
122 } while (srclen); 122 } while (srclen);
123 } 123 }
124 124
125 int crypto_nhpoly1305_setkey(struct crypto_sha 125 int crypto_nhpoly1305_setkey(struct crypto_shash *tfm,
126 const u8 *key, un 126 const u8 *key, unsigned int keylen)
127 { 127 {
128 struct nhpoly1305_key *ctx = crypto_sh 128 struct nhpoly1305_key *ctx = crypto_shash_ctx(tfm);
129 int i; 129 int i;
130 130
131 if (keylen != NHPOLY1305_KEY_SIZE) 131 if (keylen != NHPOLY1305_KEY_SIZE)
132 return -EINVAL; 132 return -EINVAL;
133 133
134 poly1305_core_setkey(&ctx->poly_key, k 134 poly1305_core_setkey(&ctx->poly_key, key);
135 key += POLY1305_BLOCK_SIZE; 135 key += POLY1305_BLOCK_SIZE;
136 136
137 for (i = 0; i < NH_KEY_WORDS; i++) 137 for (i = 0; i < NH_KEY_WORDS; i++)
138 ctx->nh_key[i] = get_unaligned 138 ctx->nh_key[i] = get_unaligned_le32(key + i * sizeof(u32));
139 139
140 return 0; 140 return 0;
141 } 141 }
142 EXPORT_SYMBOL(crypto_nhpoly1305_setkey); 142 EXPORT_SYMBOL(crypto_nhpoly1305_setkey);
143 143
144 int crypto_nhpoly1305_init(struct shash_desc * 144 int crypto_nhpoly1305_init(struct shash_desc *desc)
145 { 145 {
146 struct nhpoly1305_state *state = shash 146 struct nhpoly1305_state *state = shash_desc_ctx(desc);
147 147
148 poly1305_core_init(&state->poly_state) 148 poly1305_core_init(&state->poly_state);
149 state->buflen = 0; 149 state->buflen = 0;
150 state->nh_remaining = 0; 150 state->nh_remaining = 0;
151 return 0; 151 return 0;
152 } 152 }
153 EXPORT_SYMBOL(crypto_nhpoly1305_init); 153 EXPORT_SYMBOL(crypto_nhpoly1305_init);
154 154
155 int crypto_nhpoly1305_update_helper(struct sha 155 int crypto_nhpoly1305_update_helper(struct shash_desc *desc,
156 const u8 * 156 const u8 *src, unsigned int srclen,
157 nh_t nh_fn 157 nh_t nh_fn)
158 { 158 {
159 struct nhpoly1305_state *state = shash 159 struct nhpoly1305_state *state = shash_desc_ctx(desc);
160 const struct nhpoly1305_key *key = cry 160 const struct nhpoly1305_key *key = crypto_shash_ctx(desc->tfm);
161 unsigned int bytes; 161 unsigned int bytes;
162 162
163 if (state->buflen) { 163 if (state->buflen) {
164 bytes = min(srclen, (int)NH_ME 164 bytes = min(srclen, (int)NH_MESSAGE_UNIT - state->buflen);
165 memcpy(&state->buffer[state->b 165 memcpy(&state->buffer[state->buflen], src, bytes);
166 state->buflen += bytes; 166 state->buflen += bytes;
167 if (state->buflen < NH_MESSAGE 167 if (state->buflen < NH_MESSAGE_UNIT)
168 return 0; 168 return 0;
169 nhpoly1305_units(state, key, s 169 nhpoly1305_units(state, key, state->buffer, NH_MESSAGE_UNIT,
170 nh_fn); 170 nh_fn);
171 state->buflen = 0; 171 state->buflen = 0;
172 src += bytes; 172 src += bytes;
173 srclen -= bytes; 173 srclen -= bytes;
174 } 174 }
175 175
176 if (srclen >= NH_MESSAGE_UNIT) { 176 if (srclen >= NH_MESSAGE_UNIT) {
177 bytes = round_down(srclen, NH_ 177 bytes = round_down(srclen, NH_MESSAGE_UNIT);
178 nhpoly1305_units(state, key, s 178 nhpoly1305_units(state, key, src, bytes, nh_fn);
179 src += bytes; 179 src += bytes;
180 srclen -= bytes; 180 srclen -= bytes;
181 } 181 }
182 182
183 if (srclen) { 183 if (srclen) {
184 memcpy(state->buffer, src, src 184 memcpy(state->buffer, src, srclen);
185 state->buflen = srclen; 185 state->buflen = srclen;
186 } 186 }
187 return 0; 187 return 0;
188 } 188 }
189 EXPORT_SYMBOL(crypto_nhpoly1305_update_helper) 189 EXPORT_SYMBOL(crypto_nhpoly1305_update_helper);
190 190
191 int crypto_nhpoly1305_update(struct shash_desc 191 int crypto_nhpoly1305_update(struct shash_desc *desc,
192 const u8 *src, un 192 const u8 *src, unsigned int srclen)
193 { 193 {
194 return crypto_nhpoly1305_update_helper 194 return crypto_nhpoly1305_update_helper(desc, src, srclen, nh_generic);
195 } 195 }
196 EXPORT_SYMBOL(crypto_nhpoly1305_update); 196 EXPORT_SYMBOL(crypto_nhpoly1305_update);
197 197
198 int crypto_nhpoly1305_final_helper(struct shas 198 int crypto_nhpoly1305_final_helper(struct shash_desc *desc, u8 *dst, nh_t nh_fn)
199 { 199 {
200 struct nhpoly1305_state *state = shash 200 struct nhpoly1305_state *state = shash_desc_ctx(desc);
201 const struct nhpoly1305_key *key = cry 201 const struct nhpoly1305_key *key = crypto_shash_ctx(desc->tfm);
202 202
203 if (state->buflen) { 203 if (state->buflen) {
204 memset(&state->buffer[state->b 204 memset(&state->buffer[state->buflen], 0,
205 NH_MESSAGE_UNIT - state 205 NH_MESSAGE_UNIT - state->buflen);
206 nhpoly1305_units(state, key, s 206 nhpoly1305_units(state, key, state->buffer, NH_MESSAGE_UNIT,
207 nh_fn); 207 nh_fn);
208 } 208 }
209 209
210 if (state->nh_remaining) 210 if (state->nh_remaining)
211 process_nh_hash_value(state, k 211 process_nh_hash_value(state, key);
212 212
213 poly1305_core_emit(&state->poly_state, 213 poly1305_core_emit(&state->poly_state, NULL, dst);
214 return 0; 214 return 0;
215 } 215 }
216 EXPORT_SYMBOL(crypto_nhpoly1305_final_helper); 216 EXPORT_SYMBOL(crypto_nhpoly1305_final_helper);
217 217
218 int crypto_nhpoly1305_final(struct shash_desc 218 int crypto_nhpoly1305_final(struct shash_desc *desc, u8 *dst)
219 { 219 {
220 return crypto_nhpoly1305_final_helper( 220 return crypto_nhpoly1305_final_helper(desc, dst, nh_generic);
221 } 221 }
222 EXPORT_SYMBOL(crypto_nhpoly1305_final); 222 EXPORT_SYMBOL(crypto_nhpoly1305_final);
223 223
224 static struct shash_alg nhpoly1305_alg = { 224 static struct shash_alg nhpoly1305_alg = {
225 .base.cra_name = "nhpoly1305" 225 .base.cra_name = "nhpoly1305",
226 .base.cra_driver_name = "nhpoly1305- 226 .base.cra_driver_name = "nhpoly1305-generic",
227 .base.cra_priority = 100, 227 .base.cra_priority = 100,
228 .base.cra_ctxsize = sizeof(struc 228 .base.cra_ctxsize = sizeof(struct nhpoly1305_key),
229 .base.cra_module = THIS_MODULE, 229 .base.cra_module = THIS_MODULE,
230 .digestsize = POLY1305_DIG 230 .digestsize = POLY1305_DIGEST_SIZE,
231 .init = crypto_nhpol 231 .init = crypto_nhpoly1305_init,
232 .update = crypto_nhpol 232 .update = crypto_nhpoly1305_update,
233 .final = crypto_nhpol 233 .final = crypto_nhpoly1305_final,
234 .setkey = crypto_nhpol 234 .setkey = crypto_nhpoly1305_setkey,
235 .descsize = sizeof(struc 235 .descsize = sizeof(struct nhpoly1305_state),
236 }; 236 };
237 237
238 static int __init nhpoly1305_mod_init(void) 238 static int __init nhpoly1305_mod_init(void)
239 { 239 {
240 return crypto_register_shash(&nhpoly13 240 return crypto_register_shash(&nhpoly1305_alg);
241 } 241 }
242 242
243 static void __exit nhpoly1305_mod_exit(void) 243 static void __exit nhpoly1305_mod_exit(void)
244 { 244 {
245 crypto_unregister_shash(&nhpoly1305_al 245 crypto_unregister_shash(&nhpoly1305_alg);
246 } 246 }
247 247
248 subsys_initcall(nhpoly1305_mod_init); 248 subsys_initcall(nhpoly1305_mod_init);
249 module_exit(nhpoly1305_mod_exit); 249 module_exit(nhpoly1305_mod_exit);
250 250
251 MODULE_DESCRIPTION("NHPoly1305 ε-almost-∆-u 251 MODULE_DESCRIPTION("NHPoly1305 ε-almost-∆-universal hash function");
252 MODULE_LICENSE("GPL v2"); 252 MODULE_LICENSE("GPL v2");
253 MODULE_AUTHOR("Eric Biggers <ebiggers@google.c 253 MODULE_AUTHOR("Eric Biggers <ebiggers@google.com>");
254 MODULE_ALIAS_CRYPTO("nhpoly1305"); 254 MODULE_ALIAS_CRYPTO("nhpoly1305");
255 MODULE_ALIAS_CRYPTO("nhpoly1305-generic"); 255 MODULE_ALIAS_CRYPTO("nhpoly1305-generic");
256 256
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