github.com/onflow/flow-go@v0.35.7-crescendo-preview.23-atree-inlining/ledger/common/hash/copy_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 (
    38  	"unsafe"
    39  )
    40  
    41  // copyOutUnaligned copies 32 bytes to a hash array.
    42  func copyOut(d *state) Hash {
    43  	var out Hash
    44  	ab := (*[HashLen]uint8)(unsafe.Pointer(&d.a[0]))
    45  	copy(out[:], ab[:])
    46  	return out
    47  }
    48  
    49  // copyIn512 copies two 32 bytes arrays into the state
    50  // and writes the padding.
    51  func copyIn512(d *state, buf1, buf2 Hash) {
    52  	ab := (*[stateSize << 3]uint8)(unsafe.Pointer(&d.a[0]))
    53  	copy(ab[:], buf1[:])
    54  	copy(ab[HashLen:], buf2[:])
    55  
    56  	// dsbyte also contains the first one bit for the padding.
    57  	d.a[8] = 0x6
    58  	// copy the last padding bit
    59  	d.a[16] = paddingEnd
    60  }
    61  
    62  // copyIn256 copies a 32 bytes array into the state without padding.
    63  func copyIn256(d *state, buf Hash) {
    64  	ab := (*[stateSize << 3]uint8)(unsafe.Pointer(&d.a[0]))
    65  	copy(ab[:], buf[:])
    66  }