1 /*-
2 * Copyright (c) 2016 The Go Authors. All rights reserved.
3 * Copyright (c) 2024 Robert Clausecker <fuz@freebsd.org>
4 *
5 * Adapted from Go's crypto/sha1/sha1block_amd64.go.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are
9 * met:
10 *
11 * * Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * * Redistributions in binary form must reproduce the above
14 * copyright notice, this list of conditions and the following disclaimer
15 * in the documentation and/or other materials provided with the
16 * distribution.
17 * * Neither the name of Google Inc. nor the names of its
18 * contributors may be used to endorse or promote products derived from
19 * this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #include <machine/specialreg.h>
35 #include <sha.h>
36 #include <x86/ifunc.h>
37
38 extern void _libmd_sha1block_scalar(SHA1_CTX *, const void *, size_t);
39 extern void _libmd_sha1block_avx2(SHA1_CTX *, const void *, size_t);
40 extern void _libmd_sha1block_shani(SHA1_CTX *, const void *, size_t);
41 static void sha1block_avx2_wrapper(SHA1_CTX *, const void *, size_t);
42
43 #define AVX2_STDEXT_NEEDED \
44 (CPUID_STDEXT_BMI1 | CPUID_STDEXT_AVX2 | CPUID_STDEXT_BMI2)
45
46 DEFINE_UIFUNC(, void, sha1_block, (SHA1_CTX *, const void *, size_t))
47 {
48 if (cpu_stdext_feature & CPUID_STDEXT_SHA)
49 return (_libmd_sha1block_shani);
50 if ((cpu_stdext_feature & AVX2_STDEXT_NEEDED) == AVX2_STDEXT_NEEDED)
51 return (sha1block_avx2_wrapper);
52 else
53 return (_libmd_sha1block_scalar);
54 }
55
56 static void
sha1block_avx2_wrapper(SHA1_CTX * c,const void * data,size_t len)57 sha1block_avx2_wrapper(SHA1_CTX *c, const void *data, size_t len)
58 {
59 if (len >= 256) {
60 /*
61 * sha1block_avx2 calculates sha1 for 2 block per iteration.
62 * It also interleaves the precalculation for next the block.
63 * So it may read up-to 192 bytes past the end of p.
64 * We may add checks inside sha1block_avx2, but this will
65 * just turn it into a copy of sha1block_scalar,
66 * so call it directly, instead.
67 */
68 size_t safe_len = len - 128;
69
70 if (safe_len % 128 != 0)
71 safe_len -= 64;
72
73 _libmd_sha1block_avx2(c, data, safe_len);
74 _libmd_sha1block_scalar(c, data + safe_len, len - safe_len);
75 } else
76 _libmd_sha1block_scalar(c, data, len);
77 }
78