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> <<
21 20
22 static int crypto_poly1305_init(struct shash_d !! 21 static inline u64 mlt(u64 a, u64 b)
>> 22 {
>> 23 return a * b;
>> 24 }
>> 25
>> 26 static inline u32 sr(u64 v, u_char n)
>> 27 {
>> 28 return v >> n;
>> 29 }
>> 30
>> 31 static inline u32 and(u32 v, u32 mask)
>> 32 {
>> 33 return v & mask;
>> 34 }
>> 35
>> 36 static inline u32 le32_to_cpuvp(const void *p)
>> 37 {
>> 38 return le32_to_cpup(p);
>> 39 }
>> 40
>> 41 int crypto_poly1305_init(struct shash_desc *desc)
23 { 42 {
24 struct poly1305_desc_ctx *dctx = shash 43 struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
25 44
26 poly1305_core_init(&dctx->h); !! 45 memset(dctx->h, 0, sizeof(dctx->h));
27 dctx->buflen = 0; 46 dctx->buflen = 0;
28 dctx->rset = 0; !! 47 dctx->rset = false;
29 dctx->sset = false; 48 dctx->sset = false;
30 49
31 return 0; 50 return 0;
32 } 51 }
>> 52 EXPORT_SYMBOL_GPL(crypto_poly1305_init);
33 53
34 static unsigned int crypto_poly1305_setdesckey !! 54 static void poly1305_setrkey(struct poly1305_desc_ctx *dctx, const u8 *key)
35 !! 55 {
>> 56 /* r &= 0xffffffc0ffffffc0ffffffc0fffffff */
>> 57 dctx->r[0] = (le32_to_cpuvp(key + 0) >> 0) & 0x3ffffff;
>> 58 dctx->r[1] = (le32_to_cpuvp(key + 3) >> 2) & 0x3ffff03;
>> 59 dctx->r[2] = (le32_to_cpuvp(key + 6) >> 4) & 0x3ffc0ff;
>> 60 dctx->r[3] = (le32_to_cpuvp(key + 9) >> 6) & 0x3f03fff;
>> 61 dctx->r[4] = (le32_to_cpuvp(key + 12) >> 8) & 0x00fffff;
>> 62 }
>> 63
>> 64 static void poly1305_setskey(struct poly1305_desc_ctx *dctx, const u8 *key)
>> 65 {
>> 66 dctx->s[0] = le32_to_cpuvp(key + 0);
>> 67 dctx->s[1] = le32_to_cpuvp(key + 4);
>> 68 dctx->s[2] = le32_to_cpuvp(key + 8);
>> 69 dctx->s[3] = le32_to_cpuvp(key + 12);
>> 70 }
>> 71
>> 72 /*
>> 73 * Poly1305 requires a unique key for each tag, which implies that we can't set
>> 74 * it on the tfm that gets accessed by multiple users simultaneously. Instead we
>> 75 * expect the key as the first 32 bytes in the update() call.
>> 76 */
>> 77 unsigned int crypto_poly1305_setdesckey(struct poly1305_desc_ctx *dctx,
>> 78 const u8 *src, unsigned int srclen)
36 { 79 {
37 if (!dctx->sset) { 80 if (!dctx->sset) {
38 if (!dctx->rset && srclen >= P 81 if (!dctx->rset && srclen >= POLY1305_BLOCK_SIZE) {
39 poly1305_core_setkey(& !! 82 poly1305_setrkey(dctx, src);
40 src += POLY1305_BLOCK_ 83 src += POLY1305_BLOCK_SIZE;
41 srclen -= POLY1305_BLO 84 srclen -= POLY1305_BLOCK_SIZE;
42 dctx->rset = 2; !! 85 dctx->rset = true;
43 } 86 }
44 if (srclen >= POLY1305_BLOCK_S 87 if (srclen >= POLY1305_BLOCK_SIZE) {
45 dctx->s[0] = get_unali !! 88 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_ 89 src += POLY1305_BLOCK_SIZE;
50 srclen -= POLY1305_BLO 90 srclen -= POLY1305_BLOCK_SIZE;
51 dctx->sset = true; 91 dctx->sset = true;
52 } 92 }
53 } 93 }
54 return srclen; 94 return srclen;
55 } 95 }
>> 96 EXPORT_SYMBOL_GPL(crypto_poly1305_setdesckey);
56 97
57 static void poly1305_blocks(struct poly1305_de !! 98 static unsigned int poly1305_blocks(struct poly1305_desc_ctx *dctx,
58 unsigned int srcle !! 99 const u8 *src, unsigned int srclen,
>> 100 u32 hibit)
59 { 101 {
>> 102 u32 r0, r1, r2, r3, r4;
>> 103 u32 s1, s2, s3, s4;
>> 104 u32 h0, h1, h2, h3, h4;
>> 105 u64 d0, d1, d2, d3, d4;
60 unsigned int datalen; 106 unsigned int datalen;
61 107
62 if (unlikely(!dctx->sset)) { 108 if (unlikely(!dctx->sset)) {
63 datalen = crypto_poly1305_setd 109 datalen = crypto_poly1305_setdesckey(dctx, src, srclen);
64 src += srclen - datalen; 110 src += srclen - datalen;
65 srclen = datalen; 111 srclen = datalen;
66 } 112 }
67 113
68 poly1305_core_blocks(&dctx->h, &dctx-> !! 114 r0 = dctx->r[0];
69 srclen / POLY1305 !! 115 r1 = dctx->r[1];
>> 116 r2 = dctx->r[2];
>> 117 r3 = dctx->r[3];
>> 118 r4 = dctx->r[4];
>> 119
>> 120 s1 = r1 * 5;
>> 121 s2 = r2 * 5;
>> 122 s3 = r3 * 5;
>> 123 s4 = r4 * 5;
>> 124
>> 125 h0 = dctx->h[0];
>> 126 h1 = dctx->h[1];
>> 127 h2 = dctx->h[2];
>> 128 h3 = dctx->h[3];
>> 129 h4 = dctx->h[4];
>> 130
>> 131 while (likely(srclen >= POLY1305_BLOCK_SIZE)) {
>> 132
>> 133 /* h += m[i] */
>> 134 h0 += (le32_to_cpuvp(src + 0) >> 0) & 0x3ffffff;
>> 135 h1 += (le32_to_cpuvp(src + 3) >> 2) & 0x3ffffff;
>> 136 h2 += (le32_to_cpuvp(src + 6) >> 4) & 0x3ffffff;
>> 137 h3 += (le32_to_cpuvp(src + 9) >> 6) & 0x3ffffff;
>> 138 h4 += (le32_to_cpuvp(src + 12) >> 8) | hibit;
>> 139
>> 140 /* h *= r */
>> 141 d0 = mlt(h0, r0) + mlt(h1, s4) + mlt(h2, s3) +
>> 142 mlt(h3, s2) + mlt(h4, s1);
>> 143 d1 = mlt(h0, r1) + mlt(h1, r0) + mlt(h2, s4) +
>> 144 mlt(h3, s3) + mlt(h4, s2);
>> 145 d2 = mlt(h0, r2) + mlt(h1, r1) + mlt(h2, r0) +
>> 146 mlt(h3, s4) + mlt(h4, s3);
>> 147 d3 = mlt(h0, r3) + mlt(h1, r2) + mlt(h2, r1) +
>> 148 mlt(h3, r0) + mlt(h4, s4);
>> 149 d4 = mlt(h0, r4) + mlt(h1, r3) + mlt(h2, r2) +
>> 150 mlt(h3, r1) + mlt(h4, r0);
>> 151
>> 152 /* (partial) h %= p */
>> 153 d1 += sr(d0, 26); h0 = and(d0, 0x3ffffff);
>> 154 d2 += sr(d1, 26); h1 = and(d1, 0x3ffffff);
>> 155 d3 += sr(d2, 26); h2 = and(d2, 0x3ffffff);
>> 156 d4 += sr(d3, 26); h3 = and(d3, 0x3ffffff);
>> 157 h0 += sr(d4, 26) * 5; h4 = and(d4, 0x3ffffff);
>> 158 h1 += h0 >> 26; h0 = h0 & 0x3ffffff;
>> 159
>> 160 src += POLY1305_BLOCK_SIZE;
>> 161 srclen -= POLY1305_BLOCK_SIZE;
>> 162 }
>> 163
>> 164 dctx->h[0] = h0;
>> 165 dctx->h[1] = h1;
>> 166 dctx->h[2] = h2;
>> 167 dctx->h[3] = h3;
>> 168 dctx->h[4] = h4;
>> 169
>> 170 return srclen;
70 } 171 }
71 172
72 static int crypto_poly1305_update(struct shash !! 173 int crypto_poly1305_update(struct shash_desc *desc,
73 const u8 *sr !! 174 const u8 *src, unsigned int srclen)
74 { 175 {
75 struct poly1305_desc_ctx *dctx = shash 176 struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
76 unsigned int bytes; 177 unsigned int bytes;
77 178
78 if (unlikely(dctx->buflen)) { 179 if (unlikely(dctx->buflen)) {
79 bytes = min(srclen, POLY1305_B 180 bytes = min(srclen, POLY1305_BLOCK_SIZE - dctx->buflen);
80 memcpy(dctx->buf + dctx->bufle 181 memcpy(dctx->buf + dctx->buflen, src, bytes);
81 src += bytes; 182 src += bytes;
82 srclen -= bytes; 183 srclen -= bytes;
83 dctx->buflen += bytes; 184 dctx->buflen += bytes;
84 185
85 if (dctx->buflen == POLY1305_B 186 if (dctx->buflen == POLY1305_BLOCK_SIZE) {
86 poly1305_blocks(dctx, 187 poly1305_blocks(dctx, dctx->buf,
87 POLY13 !! 188 POLY1305_BLOCK_SIZE, 1 << 24);
88 dctx->buflen = 0; 189 dctx->buflen = 0;
89 } 190 }
90 } 191 }
91 192
92 if (likely(srclen >= POLY1305_BLOCK_SI 193 if (likely(srclen >= POLY1305_BLOCK_SIZE)) {
93 poly1305_blocks(dctx, src, src !! 194 bytes = poly1305_blocks(dctx, src, srclen, 1 << 24);
94 src += srclen - (srclen % POLY !! 195 src += srclen - bytes;
95 srclen %= POLY1305_BLOCK_SIZE; !! 196 srclen = bytes;
96 } 197 }
97 198
98 if (unlikely(srclen)) { 199 if (unlikely(srclen)) {
99 dctx->buflen = srclen; 200 dctx->buflen = srclen;
100 memcpy(dctx->buf, src, srclen) 201 memcpy(dctx->buf, src, srclen);
101 } 202 }
102 203
103 return 0; 204 return 0;
104 } 205 }
>> 206 EXPORT_SYMBOL_GPL(crypto_poly1305_update);
105 207
106 static int crypto_poly1305_final(struct shash_ !! 208 int crypto_poly1305_final(struct shash_desc *desc, u8 *dst)
107 { 209 {
108 struct poly1305_desc_ctx *dctx = shash 210 struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
>> 211 __le32 *mac = (__le32 *)dst;
>> 212 u32 h0, h1, h2, h3, h4;
>> 213 u32 g0, g1, g2, g3, g4;
>> 214 u32 mask;
>> 215 u64 f = 0;
109 216
110 if (unlikely(!dctx->sset)) 217 if (unlikely(!dctx->sset))
111 return -ENOKEY; 218 return -ENOKEY;
112 219
113 poly1305_final_generic(dctx, dst); !! 220 if (unlikely(dctx->buflen)) {
>> 221 dctx->buf[dctx->buflen++] = 1;
>> 222 memset(dctx->buf + dctx->buflen, 0,
>> 223 POLY1305_BLOCK_SIZE - dctx->buflen);
>> 224 poly1305_blocks(dctx, dctx->buf, POLY1305_BLOCK_SIZE, 0);
>> 225 }
>> 226
>> 227 /* fully carry h */
>> 228 h0 = dctx->h[0];
>> 229 h1 = dctx->h[1];
>> 230 h2 = dctx->h[2];
>> 231 h3 = dctx->h[3];
>> 232 h4 = dctx->h[4];
>> 233
>> 234 h2 += (h1 >> 26); h1 = h1 & 0x3ffffff;
>> 235 h3 += (h2 >> 26); h2 = h2 & 0x3ffffff;
>> 236 h4 += (h3 >> 26); h3 = h3 & 0x3ffffff;
>> 237 h0 += (h4 >> 26) * 5; h4 = h4 & 0x3ffffff;
>> 238 h1 += (h0 >> 26); h0 = h0 & 0x3ffffff;
>> 239
>> 240 /* compute h + -p */
>> 241 g0 = h0 + 5;
>> 242 g1 = h1 + (g0 >> 26); g0 &= 0x3ffffff;
>> 243 g2 = h2 + (g1 >> 26); g1 &= 0x3ffffff;
>> 244 g3 = h3 + (g2 >> 26); g2 &= 0x3ffffff;
>> 245 g4 = h4 + (g3 >> 26) - (1 << 26); g3 &= 0x3ffffff;
>> 246
>> 247 /* select h if h < p, or h + -p if h >= p */
>> 248 mask = (g4 >> ((sizeof(u32) * 8) - 1)) - 1;
>> 249 g0 &= mask;
>> 250 g1 &= mask;
>> 251 g2 &= mask;
>> 252 g3 &= mask;
>> 253 g4 &= mask;
>> 254 mask = ~mask;
>> 255 h0 = (h0 & mask) | g0;
>> 256 h1 = (h1 & mask) | g1;
>> 257 h2 = (h2 & mask) | g2;
>> 258 h3 = (h3 & mask) | g3;
>> 259 h4 = (h4 & mask) | g4;
>> 260
>> 261 /* h = h % (2^128) */
>> 262 h0 = (h0 >> 0) | (h1 << 26);
>> 263 h1 = (h1 >> 6) | (h2 << 20);
>> 264 h2 = (h2 >> 12) | (h3 << 14);
>> 265 h3 = (h3 >> 18) | (h4 << 8);
>> 266
>> 267 /* mac = (h + s) % (2^128) */
>> 268 f = (f >> 32) + h0 + dctx->s[0]; mac[0] = cpu_to_le32(f);
>> 269 f = (f >> 32) + h1 + dctx->s[1]; mac[1] = cpu_to_le32(f);
>> 270 f = (f >> 32) + h2 + dctx->s[2]; mac[2] = cpu_to_le32(f);
>> 271 f = (f >> 32) + h3 + dctx->s[3]; mac[3] = cpu_to_le32(f);
>> 272
114 return 0; 273 return 0;
115 } 274 }
>> 275 EXPORT_SYMBOL_GPL(crypto_poly1305_final);
116 276
117 static struct shash_alg poly1305_alg = { 277 static struct shash_alg poly1305_alg = {
118 .digestsize = POLY1305_DIGEST_SIZE 278 .digestsize = POLY1305_DIGEST_SIZE,
119 .init = crypto_poly1305_init 279 .init = crypto_poly1305_init,
120 .update = crypto_poly1305_upda 280 .update = crypto_poly1305_update,
121 .final = crypto_poly1305_fina 281 .final = crypto_poly1305_final,
122 .descsize = sizeof(struct poly13 282 .descsize = sizeof(struct poly1305_desc_ctx),
123 .base = { 283 .base = {
124 .cra_name = "pol 284 .cra_name = "poly1305",
125 .cra_driver_name = "pol 285 .cra_driver_name = "poly1305-generic",
126 .cra_priority = 100, 286 .cra_priority = 100,
>> 287 .cra_flags = CRYPTO_ALG_TYPE_SHASH,
>> 288 .cra_alignmask = sizeof(u32) - 1,
127 .cra_blocksize = POLY 289 .cra_blocksize = POLY1305_BLOCK_SIZE,
128 .cra_module = THIS 290 .cra_module = THIS_MODULE,
129 }, 291 },
130 }; 292 };
131 293
132 static int __init poly1305_mod_init(void) 294 static int __init poly1305_mod_init(void)
133 { 295 {
134 return crypto_register_shash(&poly1305 296 return crypto_register_shash(&poly1305_alg);
135 } 297 }
136 298
137 static void __exit poly1305_mod_exit(void) 299 static void __exit poly1305_mod_exit(void)
138 { 300 {
139 crypto_unregister_shash(&poly1305_alg) 301 crypto_unregister_shash(&poly1305_alg);
140 } 302 }
141 303
142 subsys_initcall(poly1305_mod_init); !! 304 module_init(poly1305_mod_init);
143 module_exit(poly1305_mod_exit); 305 module_exit(poly1305_mod_exit);
144 306
145 MODULE_LICENSE("GPL"); 307 MODULE_LICENSE("GPL");
146 MODULE_AUTHOR("Martin Willi <martin@strongswan 308 MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
147 MODULE_DESCRIPTION("Poly1305 authenticator"); 309 MODULE_DESCRIPTION("Poly1305 authenticator");
148 MODULE_ALIAS_CRYPTO("poly1305"); 310 MODULE_ALIAS_CRYPTO("poly1305");
149 MODULE_ALIAS_CRYPTO("poly1305-generic"); 311 MODULE_ALIAS_CRYPTO("poly1305-generic");
150 312
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