github.com/onflow/flow-go/crypto@v0.24.8/hash/xor_generic.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 purego
    33  
    34  package hash
    35  
    36  import "encoding/binary"
    37  
    38  // A storageBuf is an aligned array of maxRate bytes.
    39  type storageBuf [maxRate]byte
    40  
    41  func (b *storageBuf) asBytes() *[maxRate]byte {
    42  	return (*[maxRate]byte)(b)
    43  }
    44  
    45  // xorIn xors the bytes in buf into the state; it
    46  // makes no non-portable assumptions about memory layout
    47  // or alignment.
    48  func xorIn(d *spongeState, buf []byte) {
    49  	n := len(buf) / 8
    50  
    51  	for i := 0; i < n; i++ {
    52  		a := binary.LittleEndian.Uint64(buf)
    53  		d.a[i] ^= a
    54  		buf = buf[8:]
    55  	}
    56  }
    57  
    58  // copyOut copies ulint64s to a byte buffer.
    59  func copyOut(b []byte, d *spongeState) {
    60  	for i := 0; len(b) >= 8; i++ {
    61  		binary.LittleEndian.PutUint64(b, d.a[i])
    62  		b = b[8:]
    63  	}
    64  }