1 /* 1 /*
2 * Poly1305 authenticator algorithm, RFC7539 2 * Poly1305 authenticator algorithm, RFC7539
3 * 3 *
4 * Copyright (C) 2015 Martin Willi 4 * Copyright (C) 2015 Martin Willi
5 * 5 *
6 * Based on public domain code by Andrew Moon 6 * Based on public domain code by Andrew Moon and Daniel J. Bernstein.
7 * 7 *
8 * This program is free software; you can redi 8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Publi 9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either versio 10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version. 11 * (at your option) any later version.
12 */ 12 */
13 13
14 #include <crypto/algapi.h> 14 #include <crypto/algapi.h>
15 #include <crypto/internal/hash.h> 15 #include <crypto/internal/hash.h>
16 #include <crypto/internal/poly1305.h> !! 16 #include <crypto/poly1305.h>
17 #include <linux/crypto.h> 17 #include <linux/crypto.h>
18 #include <linux/kernel.h> 18 #include <linux/kernel.h>
19 #include <linux/module.h> 19 #include <linux/module.h>
20 #include <asm/unaligned.h> 20 #include <asm/unaligned.h>
21 21
22 static int crypto_poly1305_init(struct shash_d !! 22 static inline u64 mlt(u64 a, u64 b)
>> 23 {
>> 24 return a * b;
>> 25 }
>> 26
>> 27 static inline u32 sr(u64 v, u_char n)
>> 28 {
>> 29 return v >> n;
>> 30 }
>> 31
>> 32 static inline u32 and(u32 v, u32 mask)
>> 33 {
>> 34 return v & mask;
>> 35 }
>> 36
>> 37 int crypto_poly1305_init(struct shash_desc *desc)
23 { 38 {
24 struct poly1305_desc_ctx *dctx = shash 39 struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
25 40
26 poly1305_core_init(&dctx->h); !! 41 memset(dctx->h, 0, sizeof(dctx->h));
27 dctx->buflen = 0; 42 dctx->buflen = 0;
28 dctx->rset = 0; !! 43 dctx->rset = false;
29 dctx->sset = false; 44 dctx->sset = false;
30 45
31 return 0; 46 return 0;
32 } 47 }
>> 48 EXPORT_SYMBOL_GPL(crypto_poly1305_init);
>> 49
>> 50 static void poly1305_setrkey(struct poly1305_desc_ctx *dctx, const u8 *key)
>> 51 {
>> 52 /* r &= 0xffffffc0ffffffc0ffffffc0fffffff */
>> 53 dctx->r[0] = (get_unaligned_le32(key + 0) >> 0) & 0x3ffffff;
>> 54 dctx->r[1] = (get_unaligned_le32(key + 3) >> 2) & 0x3ffff03;
>> 55 dctx->r[2] = (get_unaligned_le32(key + 6) >> 4) & 0x3ffc0ff;
>> 56 dctx->r[3] = (get_unaligned_le32(key + 9) >> 6) & 0x3f03fff;
>> 57 dctx->r[4] = (get_unaligned_le32(key + 12) >> 8) & 0x00fffff;
>> 58 }
33 59
34 static unsigned int crypto_poly1305_setdesckey !! 60 static void poly1305_setskey(struct poly1305_desc_ctx *dctx, const u8 *key)
35 !! 61 {
>> 62 dctx->s[0] = get_unaligned_le32(key + 0);
>> 63 dctx->s[1] = get_unaligned_le32(key + 4);
>> 64 dctx->s[2] = get_unaligned_le32(key + 8);
>> 65 dctx->s[3] = get_unaligned_le32(key + 12);
>> 66 }
>> 67
>> 68 /*
>> 69 * Poly1305 requires a unique key for each tag, which implies that we can't set
>> 70 * it on the tfm that gets accessed by multiple users simultaneously. Instead we
>> 71 * expect the key as the first 32 bytes in the update() call.
>> 72 */
>> 73 unsigned int crypto_poly1305_setdesckey(struct poly1305_desc_ctx *dctx,
>> 74 const u8 *src, unsigned int srclen)
36 { 75 {
37 if (!dctx->sset) { 76 if (!dctx->sset) {
38 if (!dctx->rset && srclen >= P 77 if (!dctx->rset && srclen >= POLY1305_BLOCK_SIZE) {
39 poly1305_core_setkey(& !! 78 poly1305_setrkey(dctx, src);
40 src += POLY1305_BLOCK_ 79 src += POLY1305_BLOCK_SIZE;
41 srclen -= POLY1305_BLO 80 srclen -= POLY1305_BLOCK_SIZE;
42 dctx->rset = 2; !! 81 dctx->rset = true;
43 } 82 }
44 if (srclen >= POLY1305_BLOCK_S 83 if (srclen >= POLY1305_BLOCK_SIZE) {
45 dctx->s[0] = get_unali !! 84 poly1305_setskey(dctx, src);
46 dctx->s[1] = get_unali <<
47 dctx->s[2] = get_unali <<
48 dctx->s[3] = get_unali <<
49 src += POLY1305_BLOCK_ 85 src += POLY1305_BLOCK_SIZE;
50 srclen -= POLY1305_BLO 86 srclen -= POLY1305_BLOCK_SIZE;
51 dctx->sset = true; 87 dctx->sset = true;
52 } 88 }
53 } 89 }
54 return srclen; 90 return srclen;
55 } 91 }
>> 92 EXPORT_SYMBOL_GPL(crypto_poly1305_setdesckey);
56 93
57 static void poly1305_blocks(struct poly1305_de !! 94 static unsigned int poly1305_blocks(struct poly1305_desc_ctx *dctx,
58 unsigned int srcle !! 95 const u8 *src, unsigned int srclen,
>> 96 u32 hibit)
59 { 97 {
>> 98 u32 r0, r1, r2, r3, r4;
>> 99 u32 s1, s2, s3, s4;
>> 100 u32 h0, h1, h2, h3, h4;
>> 101 u64 d0, d1, d2, d3, d4;
60 unsigned int datalen; 102 unsigned int datalen;
61 103
62 if (unlikely(!dctx->sset)) { 104 if (unlikely(!dctx->sset)) {
63 datalen = crypto_poly1305_setd 105 datalen = crypto_poly1305_setdesckey(dctx, src, srclen);
64 src += srclen - datalen; 106 src += srclen - datalen;
65 srclen = datalen; 107 srclen = datalen;
66 } 108 }
67 109
68 poly1305_core_blocks(&dctx->h, &dctx-> !! 110 r0 = dctx->r[0];
69 srclen / POLY1305 !! 111 r1 = dctx->r[1];
>> 112 r2 = dctx->r[2];
>> 113 r3 = dctx->r[3];
>> 114 r4 = dctx->r[4];
>> 115
>> 116 s1 = r1 * 5;
>> 117 s2 = r2 * 5;
>> 118 s3 = r3 * 5;
>> 119 s4 = r4 * 5;
>> 120
>> 121 h0 = dctx->h[0];
>> 122 h1 = dctx->h[1];
>> 123 h2 = dctx->h[2];
>> 124 h3 = dctx->h[3];
>> 125 h4 = dctx->h[4];
>> 126
>> 127 while (likely(srclen >= POLY1305_BLOCK_SIZE)) {
>> 128
>> 129 /* h += m[i] */
>> 130 h0 += (get_unaligned_le32(src + 0) >> 0) & 0x3ffffff;
>> 131 h1 += (get_unaligned_le32(src + 3) >> 2) & 0x3ffffff;
>> 132 h2 += (get_unaligned_le32(src + 6) >> 4) & 0x3ffffff;
>> 133 h3 += (get_unaligned_le32(src + 9) >> 6) & 0x3ffffff;
>> 134 h4 += (get_unaligned_le32(src + 12) >> 8) | hibit;
>> 135
>> 136 /* h *= r */
>> 137 d0 = mlt(h0, r0) + mlt(h1, s4) + mlt(h2, s3) +
>> 138 mlt(h3, s2) + mlt(h4, s1);
>> 139 d1 = mlt(h0, r1) + mlt(h1, r0) + mlt(h2, s4) +
>> 140 mlt(h3, s3) + mlt(h4, s2);
>> 141 d2 = mlt(h0, r2) + mlt(h1, r1) + mlt(h2, r0) +
>> 142 mlt(h3, s4) + mlt(h4, s3);
>> 143 d3 = mlt(h0, r3) + mlt(h1, r2) + mlt(h2, r1) +
>> 144 mlt(h3, r0) + mlt(h4, s4);
>> 145 d4 = mlt(h0, r4) + mlt(h1, r3) + mlt(h2, r2) +
>> 146 mlt(h3, r1) + mlt(h4, r0);
>> 147
>> 148 /* (partial) h %= p */
>> 149 d1 += sr(d0, 26); h0 = and(d0, 0x3ffffff);
>> 150 d2 += sr(d1, 26); h1 = and(d1, 0x3ffffff);
>> 151 d3 += sr(d2, 26); h2 = and(d2, 0x3ffffff);
>> 152 d4 += sr(d3, 26); h3 = and(d3, 0x3ffffff);
>> 153 h0 += sr(d4, 26) * 5; h4 = and(d4, 0x3ffffff);
>> 154 h1 += h0 >> 26; h0 = h0 & 0x3ffffff;
>> 155
>> 156 src += POLY1305_BLOCK_SIZE;
>> 157 srclen -= POLY1305_BLOCK_SIZE;
>> 158 }
>> 159
>> 160 dctx->h[0] = h0;
>> 161 dctx->h[1] = h1;
>> 162 dctx->h[2] = h2;
>> 163 dctx->h[3] = h3;
>> 164 dctx->h[4] = h4;
>> 165
>> 166 return srclen;
70 } 167 }
71 168
72 static int crypto_poly1305_update(struct shash !! 169 int crypto_poly1305_update(struct shash_desc *desc,
73 const u8 *sr !! 170 const u8 *src, unsigned int srclen)
74 { 171 {
75 struct poly1305_desc_ctx *dctx = shash 172 struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
76 unsigned int bytes; 173 unsigned int bytes;
77 174
78 if (unlikely(dctx->buflen)) { 175 if (unlikely(dctx->buflen)) {
79 bytes = min(srclen, POLY1305_B 176 bytes = min(srclen, POLY1305_BLOCK_SIZE - dctx->buflen);
80 memcpy(dctx->buf + dctx->bufle 177 memcpy(dctx->buf + dctx->buflen, src, bytes);
81 src += bytes; 178 src += bytes;
82 srclen -= bytes; 179 srclen -= bytes;
83 dctx->buflen += bytes; 180 dctx->buflen += bytes;
84 181
85 if (dctx->buflen == POLY1305_B 182 if (dctx->buflen == POLY1305_BLOCK_SIZE) {
86 poly1305_blocks(dctx, 183 poly1305_blocks(dctx, dctx->buf,
87 POLY13 !! 184 POLY1305_BLOCK_SIZE, 1 << 24);
88 dctx->buflen = 0; 185 dctx->buflen = 0;
89 } 186 }
90 } 187 }
91 188
92 if (likely(srclen >= POLY1305_BLOCK_SI 189 if (likely(srclen >= POLY1305_BLOCK_SIZE)) {
93 poly1305_blocks(dctx, src, src !! 190 bytes = poly1305_blocks(dctx, src, srclen, 1 << 24);
94 src += srclen - (srclen % POLY !! 191 src += srclen - bytes;
95 srclen %= POLY1305_BLOCK_SIZE; !! 192 srclen = bytes;
96 } 193 }
97 194
98 if (unlikely(srclen)) { 195 if (unlikely(srclen)) {
99 dctx->buflen = srclen; 196 dctx->buflen = srclen;
100 memcpy(dctx->buf, src, srclen) 197 memcpy(dctx->buf, src, srclen);
101 } 198 }
102 199
103 return 0; 200 return 0;
104 } 201 }
>> 202 EXPORT_SYMBOL_GPL(crypto_poly1305_update);
105 203
106 static int crypto_poly1305_final(struct shash_ !! 204 int crypto_poly1305_final(struct shash_desc *desc, u8 *dst)
107 { 205 {
108 struct poly1305_desc_ctx *dctx = shash 206 struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
>> 207 u32 h0, h1, h2, h3, h4;
>> 208 u32 g0, g1, g2, g3, g4;
>> 209 u32 mask;
>> 210 u64 f = 0;
109 211
110 if (unlikely(!dctx->sset)) 212 if (unlikely(!dctx->sset))
111 return -ENOKEY; 213 return -ENOKEY;
112 214
113 poly1305_final_generic(dctx, dst); !! 215 if (unlikely(dctx->buflen)) {
>> 216 dctx->buf[dctx->buflen++] = 1;
>> 217 memset(dctx->buf + dctx->buflen, 0,
>> 218 POLY1305_BLOCK_SIZE - dctx->buflen);
>> 219 poly1305_blocks(dctx, dctx->buf, POLY1305_BLOCK_SIZE, 0);
>> 220 }
>> 221
>> 222 /* fully carry h */
>> 223 h0 = dctx->h[0];
>> 224 h1 = dctx->h[1];
>> 225 h2 = dctx->h[2];
>> 226 h3 = dctx->h[3];
>> 227 h4 = dctx->h[4];
>> 228
>> 229 h2 += (h1 >> 26); h1 = h1 & 0x3ffffff;
>> 230 h3 += (h2 >> 26); h2 = h2 & 0x3ffffff;
>> 231 h4 += (h3 >> 26); h3 = h3 & 0x3ffffff;
>> 232 h0 += (h4 >> 26) * 5; h4 = h4 & 0x3ffffff;
>> 233 h1 += (h0 >> 26); h0 = h0 & 0x3ffffff;
>> 234
>> 235 /* compute h + -p */
>> 236 g0 = h0 + 5;
>> 237 g1 = h1 + (g0 >> 26); g0 &= 0x3ffffff;
>> 238 g2 = h2 + (g1 >> 26); g1 &= 0x3ffffff;
>> 239 g3 = h3 + (g2 >> 26); g2 &= 0x3ffffff;
>> 240 g4 = h4 + (g3 >> 26) - (1 << 26); g3 &= 0x3ffffff;
>> 241
>> 242 /* select h if h < p, or h + -p if h >= p */
>> 243 mask = (g4 >> ((sizeof(u32) * 8) - 1)) - 1;
>> 244 g0 &= mask;
>> 245 g1 &= mask;
>> 246 g2 &= mask;
>> 247 g3 &= mask;
>> 248 g4 &= mask;
>> 249 mask = ~mask;
>> 250 h0 = (h0 & mask) | g0;
>> 251 h1 = (h1 & mask) | g1;
>> 252 h2 = (h2 & mask) | g2;
>> 253 h3 = (h3 & mask) | g3;
>> 254 h4 = (h4 & mask) | g4;
>> 255
>> 256 /* h = h % (2^128) */
>> 257 h0 = (h0 >> 0) | (h1 << 26);
>> 258 h1 = (h1 >> 6) | (h2 << 20);
>> 259 h2 = (h2 >> 12) | (h3 << 14);
>> 260 h3 = (h3 >> 18) | (h4 << 8);
>> 261
>> 262 /* mac = (h + s) % (2^128) */
>> 263 f = (f >> 32) + h0 + dctx->s[0]; put_unaligned_le32(f, dst + 0);
>> 264 f = (f >> 32) + h1 + dctx->s[1]; put_unaligned_le32(f, dst + 4);
>> 265 f = (f >> 32) + h2 + dctx->s[2]; put_unaligned_le32(f, dst + 8);
>> 266 f = (f >> 32) + h3 + dctx->s[3]; put_unaligned_le32(f, dst + 12);
>> 267
114 return 0; 268 return 0;
115 } 269 }
>> 270 EXPORT_SYMBOL_GPL(crypto_poly1305_final);
116 271
117 static struct shash_alg poly1305_alg = { 272 static struct shash_alg poly1305_alg = {
118 .digestsize = POLY1305_DIGEST_SIZE 273 .digestsize = POLY1305_DIGEST_SIZE,
119 .init = crypto_poly1305_init 274 .init = crypto_poly1305_init,
120 .update = crypto_poly1305_upda 275 .update = crypto_poly1305_update,
121 .final = crypto_poly1305_fina 276 .final = crypto_poly1305_final,
122 .descsize = sizeof(struct poly13 277 .descsize = sizeof(struct poly1305_desc_ctx),
123 .base = { 278 .base = {
124 .cra_name = "pol 279 .cra_name = "poly1305",
125 .cra_driver_name = "pol 280 .cra_driver_name = "poly1305-generic",
126 .cra_priority = 100, 281 .cra_priority = 100,
>> 282 .cra_flags = CRYPTO_ALG_TYPE_SHASH,
127 .cra_blocksize = POLY 283 .cra_blocksize = POLY1305_BLOCK_SIZE,
128 .cra_module = THIS 284 .cra_module = THIS_MODULE,
129 }, 285 },
130 }; 286 };
131 287
132 static int __init poly1305_mod_init(void) 288 static int __init poly1305_mod_init(void)
133 { 289 {
134 return crypto_register_shash(&poly1305 290 return crypto_register_shash(&poly1305_alg);
135 } 291 }
136 292
137 static void __exit poly1305_mod_exit(void) 293 static void __exit poly1305_mod_exit(void)
138 { 294 {
139 crypto_unregister_shash(&poly1305_alg) 295 crypto_unregister_shash(&poly1305_alg);
140 } 296 }
141 297
142 subsys_initcall(poly1305_mod_init); !! 298 module_init(poly1305_mod_init);
143 module_exit(poly1305_mod_exit); 299 module_exit(poly1305_mod_exit);
144 300
145 MODULE_LICENSE("GPL"); 301 MODULE_LICENSE("GPL");
146 MODULE_AUTHOR("Martin Willi <martin@strongswan 302 MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
147 MODULE_DESCRIPTION("Poly1305 authenticator"); 303 MODULE_DESCRIPTION("Poly1305 authenticator");
148 MODULE_ALIAS_CRYPTO("poly1305"); 304 MODULE_ALIAS_CRYPTO("poly1305");
149 MODULE_ALIAS_CRYPTO("poly1305-generic"); 305 MODULE_ALIAS_CRYPTO("poly1305-generic");
150 306
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