github.com/onflow/flow-go/crypto@v0.24.8/hash/xor_unaligned.go (about) 1 /// The functions below were copied and modified from golang.org/x/crypto/sha3. 2 // 3 // Copyright (c) 2009 The Go Authors. All rights reserved. 4 5 // Redistribution and use in source and binary forms, with or without 6 // modification, are permitted provided that the following conditions are 7 // met: 8 9 // * Redistributions of source code must retain the above copyright 10 // notice, this list of conditions and the following disclaimer. 11 // * Redistributions in binary form must reproduce the above 12 // copyright notice, this list of conditions and the following disclaimer 13 // in the documentation and/or other materials provided with the 14 // distribution. 15 // * Neither the name of Google Inc. nor the names of its 16 // contributors may be used to endorse or promote products derived from 17 // this software without specific prior written permission. 18 19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 31 //go:build (amd64 || 386 || ppc64le) && !purego 32 // +build amd64 386 ppc64le 33 // +build !purego 34 35 package hash 36 37 import "unsafe" 38 39 // A storageBuf is an aligned array of maxRate bytes. 40 type storageBuf [maxRate / 8]uint64 41 42 //go:nocheckptr ignore "pointer arithmetic result points to invalid allocation" 43 func (b *storageBuf) asBytes() *[maxRate]byte { 44 // re-using a trick from https://github.com/golang/go/blob/master/src/runtime/stubs.go#L178: 45 // to hide the input pointer from escape analysis and avoid 46 // an escape to to the heap. The 0 xor tricks the escape analysis tool 47 // to think "ptr" and "b" are not related. 48 ptr := uintptr(unsafe.Pointer(b)) ^ 0 // nolint:staticcheck 49 return (*[maxRate]byte)(unsafe.Pointer(ptr)) 50 } 51 52 // xorIn uses unaligned reads and writes to update d.a to contain d.a 53 // XOR buf. 54 func xorIn(d *spongeState, buf []byte) { 55 n := len(buf) 56 bw := (*[maxRate / 8]uint64)(unsafe.Pointer(&buf[0]))[: n/8 : n/8] 57 58 d.a[0] ^= bw[0] 59 d.a[1] ^= bw[1] 60 d.a[2] ^= bw[2] 61 d.a[3] ^= bw[3] 62 d.a[4] ^= bw[4] 63 d.a[5] ^= bw[5] 64 d.a[6] ^= bw[6] 65 d.a[7] ^= bw[7] 66 d.a[8] ^= bw[8] 67 d.a[9] ^= bw[9] 68 d.a[10] ^= bw[10] 69 d.a[11] ^= bw[11] 70 d.a[12] ^= bw[12] 71 if n >= 136 { 72 d.a[13] ^= bw[13] 73 d.a[14] ^= bw[14] 74 d.a[15] ^= bw[15] 75 d.a[16] ^= bw[16] 76 } 77 } 78 79 func copyOut(buf []byte, d *spongeState) { 80 ab := (*[maxRate]uint8)(unsafe.Pointer(&d.a[0])) 81 copy(buf, ab[:]) 82 }