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d7d7b853 | 1 | // SPDX-License-Identifier: GPL-2.0 OR MIT |
c70f4abe | 2 | /* |
d7d7b853 | 3 | * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. |
c70f4abe MW |
4 | */ |
5 | ||
6 | #include <crypto/algapi.h> | |
7 | #include <crypto/internal/hash.h> | |
48ea8c6e | 8 | #include <crypto/internal/poly1305.h> |
f2abe0d7 | 9 | #include <crypto/internal/simd.h> |
c70f4abe | 10 | #include <linux/crypto.h> |
f0e89bcf | 11 | #include <linux/jump_label.h> |
c70f4abe MW |
12 | #include <linux/kernel.h> |
13 | #include <linux/module.h> | |
0c3dc787 | 14 | #include <linux/sizes.h> |
d7d7b853 | 15 | #include <asm/intel-family.h> |
c70f4abe MW |
16 | #include <asm/simd.h> |
17 | ||
d7d7b853 | 18 | asmlinkage void poly1305_init_x86_64(void *ctx, |
8d195e7a | 19 | const u8 key[POLY1305_BLOCK_SIZE]); |
d7d7b853 JD |
20 | asmlinkage void poly1305_blocks_x86_64(void *ctx, const u8 *inp, |
21 | const size_t len, const u32 padbit); | |
22 | asmlinkage void poly1305_emit_x86_64(void *ctx, u8 mac[POLY1305_DIGEST_SIZE], | |
23 | const u32 nonce[4]); | |
24 | asmlinkage void poly1305_emit_avx(void *ctx, u8 mac[POLY1305_DIGEST_SIZE], | |
25 | const u32 nonce[4]); | |
26 | asmlinkage void poly1305_blocks_avx(void *ctx, const u8 *inp, const size_t len, | |
27 | const u32 padbit); | |
28 | asmlinkage void poly1305_blocks_avx2(void *ctx, const u8 *inp, const size_t len, | |
29 | const u32 padbit); | |
30 | asmlinkage void poly1305_blocks_avx512(void *ctx, const u8 *inp, | |
31 | const size_t len, const u32 padbit); | |
32 | ||
33 | static __ro_after_init DEFINE_STATIC_KEY_FALSE(poly1305_use_avx); | |
f0e89bcf | 34 | static __ro_after_init DEFINE_STATIC_KEY_FALSE(poly1305_use_avx2); |
d7d7b853 JD |
35 | static __ro_after_init DEFINE_STATIC_KEY_FALSE(poly1305_use_avx512); |
36 | ||
37 | struct poly1305_arch_internal { | |
38 | union { | |
39 | struct { | |
40 | u32 h[5]; | |
41 | u32 is_base2_26; | |
42 | }; | |
43 | u64 hs[3]; | |
44 | }; | |
45 | u64 r[2]; | |
46 | u64 pad; | |
47 | struct { u32 r2, r1, r4, r3; } rn[9]; | |
48 | }; | |
da35b22d | 49 | |
d7d7b853 JD |
50 | /* The AVX code uses base 2^26, while the scalar code uses base 2^64. If we hit |
51 | * the unfortunate situation of using AVX and then having to go back to scalar | |
52 | * -- because the user is silly and has called the update function from two | |
53 | * separate contexts -- then we need to convert back to the original base before | |
54 | * proceeding. It is possible to reason that the initial reduction below is | |
55 | * sufficient given the implementation invariants. However, for an avoidance of | |
56 | * doubt and because this is not performance critical, we do the full reduction | |
57 | * anyway. Z3 proof of below function: https://xn--4db.cc/ltPtHCKN/py | |
58 | */ | |
59 | static void convert_to_base2_64(void *ctx) | |
1c08a104 | 60 | { |
d7d7b853 JD |
61 | struct poly1305_arch_internal *state = ctx; |
62 | u32 cy; | |
1c08a104 | 63 | |
d7d7b853 JD |
64 | if (!state->is_base2_26) |
65 | return; | |
1c08a104 | 66 | |
d7d7b853 JD |
67 | cy = state->h[0] >> 26; state->h[0] &= 0x3ffffff; state->h[1] += cy; |
68 | cy = state->h[1] >> 26; state->h[1] &= 0x3ffffff; state->h[2] += cy; | |
69 | cy = state->h[2] >> 26; state->h[2] &= 0x3ffffff; state->h[3] += cy; | |
70 | cy = state->h[3] >> 26; state->h[3] &= 0x3ffffff; state->h[4] += cy; | |
71 | state->hs[0] = ((u64)state->h[2] << 52) | ((u64)state->h[1] << 26) | state->h[0]; | |
72 | state->hs[1] = ((u64)state->h[4] << 40) | ((u64)state->h[3] << 14) | (state->h[2] >> 12); | |
73 | state->hs[2] = state->h[4] >> 24; | |
74 | #define ULT(a, b) ((a ^ ((a ^ b) | ((a - b) ^ b))) >> (sizeof(a) * 8 - 1)) | |
75 | cy = (state->hs[2] >> 2) + (state->hs[2] & ~3ULL); | |
76 | state->hs[2] &= 3; | |
77 | state->hs[0] += cy; | |
78 | state->hs[1] += (cy = ULT(state->hs[0], cy)); | |
79 | state->hs[2] += ULT(state->hs[1], cy); | |
80 | #undef ULT | |
81 | state->is_base2_26 = 0; | |
1c08a104 JD |
82 | } |
83 | ||
8d195e7a | 84 | static void poly1305_simd_init(void *ctx, const u8 key[POLY1305_BLOCK_SIZE]) |
da35b22d | 85 | { |
d7d7b853 | 86 | poly1305_init_x86_64(ctx, key); |
da35b22d | 87 | } |
c70f4abe | 88 | |
d7d7b853 JD |
89 | static void poly1305_simd_blocks(void *ctx, const u8 *inp, size_t len, |
90 | const u32 padbit) | |
1c08a104 | 91 | { |
d7d7b853 | 92 | struct poly1305_arch_internal *state = ctx; |
1c08a104 | 93 | |
d7d7b853 | 94 | /* SIMD disables preemption, so relax after processing each page. */ |
706024a5 JD |
95 | BUILD_BUG_ON(SZ_4K < POLY1305_BLOCK_SIZE || |
96 | SZ_4K % POLY1305_BLOCK_SIZE); | |
1c08a104 | 97 | |
42251572 | 98 | if (!static_branch_likely(&poly1305_use_avx) || |
d7d7b853 JD |
99 | (len < (POLY1305_BLOCK_SIZE * 18) && !state->is_base2_26) || |
100 | !crypto_simd_usable()) { | |
101 | convert_to_base2_64(ctx); | |
102 | poly1305_blocks_x86_64(ctx, inp, len, padbit); | |
1c08a104 | 103 | return; |
d7d7b853 | 104 | } |
1c08a104 | 105 | |
706024a5 JD |
106 | do { |
107 | const size_t bytes = min_t(size_t, len, SZ_4K); | |
d7d7b853 JD |
108 | |
109 | kernel_fpu_begin(); | |
110 | if (IS_ENABLED(CONFIG_AS_AVX512) && static_branch_likely(&poly1305_use_avx512)) | |
111 | poly1305_blocks_avx512(ctx, inp, bytes, padbit); | |
e6abef61 | 112 | else if (static_branch_likely(&poly1305_use_avx2)) |
d7d7b853 JD |
113 | poly1305_blocks_avx2(ctx, inp, bytes, padbit); |
114 | else | |
115 | poly1305_blocks_avx(ctx, inp, bytes, padbit); | |
116 | kernel_fpu_end(); | |
706024a5 | 117 | |
d7d7b853 | 118 | len -= bytes; |
d7d7b853 | 119 | inp += bytes; |
706024a5 | 120 | } while (len); |
1c08a104 JD |
121 | } |
122 | ||
d7d7b853 JD |
123 | static void poly1305_simd_emit(void *ctx, u8 mac[POLY1305_DIGEST_SIZE], |
124 | const u32 nonce[4]) | |
1c08a104 | 125 | { |
42251572 | 126 | if (!static_branch_likely(&poly1305_use_avx)) |
d7d7b853 | 127 | poly1305_emit_x86_64(ctx, mac, nonce); |
f9e7fe32 | 128 | else |
d7d7b853 | 129 | poly1305_emit_avx(ctx, mac, nonce); |
1c08a104 JD |
130 | } |
131 | ||
8d195e7a | 132 | void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 key[POLY1305_KEY_SIZE]) |
1c08a104 | 133 | { |
d7d7b853 JD |
134 | poly1305_simd_init(&dctx->h, key); |
135 | dctx->s[0] = get_unaligned_le32(&key[16]); | |
136 | dctx->s[1] = get_unaligned_le32(&key[20]); | |
137 | dctx->s[2] = get_unaligned_le32(&key[24]); | |
138 | dctx->s[3] = get_unaligned_le32(&key[28]); | |
139 | dctx->buflen = 0; | |
140 | dctx->sset = true; | |
1c08a104 | 141 | } |
d7d7b853 | 142 | EXPORT_SYMBOL(poly1305_init_arch); |
1c08a104 | 143 | |
d7d7b853 JD |
144 | static unsigned int crypto_poly1305_setdctxkey(struct poly1305_desc_ctx *dctx, |
145 | const u8 *inp, unsigned int len) | |
1c08a104 | 146 | { |
d7d7b853 JD |
147 | unsigned int acc = 0; |
148 | if (unlikely(!dctx->sset)) { | |
149 | if (!dctx->rset && len >= POLY1305_BLOCK_SIZE) { | |
150 | poly1305_simd_init(&dctx->h, inp); | |
151 | inp += POLY1305_BLOCK_SIZE; | |
152 | len -= POLY1305_BLOCK_SIZE; | |
153 | acc += POLY1305_BLOCK_SIZE; | |
1c08a104 JD |
154 | dctx->rset = 1; |
155 | } | |
d7d7b853 JD |
156 | if (len >= POLY1305_BLOCK_SIZE) { |
157 | dctx->s[0] = get_unaligned_le32(&inp[0]); | |
158 | dctx->s[1] = get_unaligned_le32(&inp[4]); | |
159 | dctx->s[2] = get_unaligned_le32(&inp[8]); | |
160 | dctx->s[3] = get_unaligned_le32(&inp[12]); | |
c3a98c3a | 161 | acc += POLY1305_BLOCK_SIZE; |
1c08a104 JD |
162 | dctx->sset = true; |
163 | } | |
164 | } | |
d7d7b853 | 165 | return acc; |
c70f4abe MW |
166 | } |
167 | ||
f0e89bcf AB |
168 | void poly1305_update_arch(struct poly1305_desc_ctx *dctx, const u8 *src, |
169 | unsigned int srclen) | |
c70f4abe | 170 | { |
d7d7b853 | 171 | unsigned int bytes, used; |
c70f4abe | 172 | |
c70f4abe MW |
173 | if (unlikely(dctx->buflen)) { |
174 | bytes = min(srclen, POLY1305_BLOCK_SIZE - dctx->buflen); | |
175 | memcpy(dctx->buf + dctx->buflen, src, bytes); | |
176 | src += bytes; | |
177 | srclen -= bytes; | |
178 | dctx->buflen += bytes; | |
179 | ||
180 | if (dctx->buflen == POLY1305_BLOCK_SIZE) { | |
d7d7b853 JD |
181 | if (likely(!crypto_poly1305_setdctxkey(dctx, dctx->buf, POLY1305_BLOCK_SIZE))) |
182 | poly1305_simd_blocks(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 1); | |
c70f4abe MW |
183 | dctx->buflen = 0; |
184 | } | |
185 | } | |
186 | ||
187 | if (likely(srclen >= POLY1305_BLOCK_SIZE)) { | |
d7d7b853 JD |
188 | bytes = round_down(srclen, POLY1305_BLOCK_SIZE); |
189 | srclen -= bytes; | |
190 | used = crypto_poly1305_setdctxkey(dctx, src, bytes); | |
191 | if (likely(bytes - used)) | |
192 | poly1305_simd_blocks(&dctx->h, src + used, bytes - used, 1); | |
193 | src += bytes; | |
c70f4abe MW |
194 | } |
195 | ||
c70f4abe MW |
196 | if (unlikely(srclen)) { |
197 | dctx->buflen = srclen; | |
198 | memcpy(dctx->buf, src, srclen); | |
199 | } | |
1b2c6a51 | 200 | } |
f0e89bcf AB |
201 | EXPORT_SYMBOL(poly1305_update_arch); |
202 | ||
d7d7b853 | 203 | void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst) |
f0e89bcf | 204 | { |
d7d7b853 JD |
205 | if (unlikely(dctx->buflen)) { |
206 | dctx->buf[dctx->buflen++] = 1; | |
207 | memset(dctx->buf + dctx->buflen, 0, | |
208 | POLY1305_BLOCK_SIZE - dctx->buflen); | |
209 | poly1305_simd_blocks(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0); | |
1c08a104 JD |
210 | } |
211 | ||
d7d7b853 | 212 | poly1305_simd_emit(&dctx->h, dst, dctx->s); |
458c0480 | 213 | memzero_explicit(dctx, sizeof(*dctx)); |
f0e89bcf AB |
214 | } |
215 | EXPORT_SYMBOL(poly1305_final_arch); | |
1b2c6a51 AB |
216 | |
217 | static int crypto_poly1305_init(struct shash_desc *desc) | |
218 | { | |
219 | struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc); | |
220 | ||
d7d7b853 | 221 | *dctx = (struct poly1305_desc_ctx){}; |
1b2c6a51 AB |
222 | return 0; |
223 | } | |
224 | ||
d7d7b853 JD |
225 | static int crypto_poly1305_update(struct shash_desc *desc, |
226 | const u8 *src, unsigned int srclen) | |
1b2c6a51 AB |
227 | { |
228 | struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc); | |
229 | ||
d7d7b853 | 230 | poly1305_update_arch(dctx, src, srclen); |
c70f4abe MW |
231 | return 0; |
232 | } | |
233 | ||
d7d7b853 | 234 | static int crypto_poly1305_final(struct shash_desc *desc, u8 *dst) |
f0e89bcf AB |
235 | { |
236 | struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc); | |
237 | ||
d7d7b853 JD |
238 | if (unlikely(!dctx->sset)) |
239 | return -ENOKEY; | |
240 | ||
241 | poly1305_final_arch(dctx, dst); | |
f0e89bcf AB |
242 | return 0; |
243 | } | |
244 | ||
c70f4abe MW |
245 | static struct shash_alg alg = { |
246 | .digestsize = POLY1305_DIGEST_SIZE, | |
ad8f5b88 | 247 | .init = crypto_poly1305_init, |
d7d7b853 | 248 | .update = crypto_poly1305_update, |
c70f4abe | 249 | .final = crypto_poly1305_final, |
ad8f5b88 | 250 | .descsize = sizeof(struct poly1305_desc_ctx), |
c70f4abe MW |
251 | .base = { |
252 | .cra_name = "poly1305", | |
253 | .cra_driver_name = "poly1305-simd", | |
254 | .cra_priority = 300, | |
c70f4abe MW |
255 | .cra_blocksize = POLY1305_BLOCK_SIZE, |
256 | .cra_module = THIS_MODULE, | |
257 | }, | |
258 | }; | |
259 | ||
260 | static int __init poly1305_simd_mod_init(void) | |
261 | { | |
42251572 | 262 | if (boot_cpu_has(X86_FEATURE_AVX) && |
d7d7b853 JD |
263 | cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL)) |
264 | static_branch_enable(&poly1305_use_avx); | |
e6abef61 | 265 | if (boot_cpu_has(X86_FEATURE_AVX) && boot_cpu_has(X86_FEATURE_AVX2) && |
f0e89bcf AB |
266 | cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL)) |
267 | static_branch_enable(&poly1305_use_avx2); | |
d7d7b853 JD |
268 | if (IS_ENABLED(CONFIG_AS_AVX512) && boot_cpu_has(X86_FEATURE_AVX) && |
269 | boot_cpu_has(X86_FEATURE_AVX2) && boot_cpu_has(X86_FEATURE_AVX512F) && | |
270 | cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM | XFEATURE_MASK_AVX512, NULL) && | |
271 | /* Skylake downclocks unacceptably much when using zmm, but later generations are fast. */ | |
272 | boot_cpu_data.x86_model != INTEL_FAM6_SKYLAKE_X) | |
273 | static_branch_enable(&poly1305_use_avx512); | |
8394bfec | 274 | return IS_REACHABLE(CONFIG_CRYPTO_HASH) ? crypto_register_shash(&alg) : 0; |
c70f4abe MW |
275 | } |
276 | ||
277 | static void __exit poly1305_simd_mod_exit(void) | |
278 | { | |
8394bfec JD |
279 | if (IS_REACHABLE(CONFIG_CRYPTO_HASH)) |
280 | crypto_unregister_shash(&alg); | |
c70f4abe MW |
281 | } |
282 | ||
283 | module_init(poly1305_simd_mod_init); | |
284 | module_exit(poly1305_simd_mod_exit); | |
285 | ||
286 | MODULE_LICENSE("GPL"); | |
d7d7b853 | 287 | MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>"); |
c70f4abe MW |
288 | MODULE_DESCRIPTION("Poly1305 authenticator"); |
289 | MODULE_ALIAS_CRYPTO("poly1305"); | |
290 | MODULE_ALIAS_CRYPTO("poly1305-simd"); |