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authorRicardo Catalinas Jiménez <r@untroubled.be>2016-02-22 06:00:43 +0800
committerRicardo Catalinas Jiménez <r@untroubled.be>2016-02-22 06:34:34 +0800
commit0a1da69fac3766b48a116580295f98df93122503 (patch)
tree9325176034343d5528f7eed1cf105c8bd03e8f68 /crypto/sha3/sha3.go
parentf8d98f7fcd08bd2eff36d5366ac2a14b52255d57 (diff)
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crypto/sha3: Delete old copied code
Diffstat (limited to 'crypto/sha3/sha3.go')
-rw-r--r--crypto/sha3/sha3.go237
1 files changed, 0 insertions, 237 deletions
diff --git a/crypto/sha3/sha3.go b/crypto/sha3/sha3.go
deleted file mode 100644
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--- a/crypto/sha3/sha3.go
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-// Copyright 2013 The Go Authors. All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-// * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-// * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-// * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-// Package sha3 implements the SHA3 hash algorithm (formerly called Keccak) chosen by NIST in 2012.
-// This file provides a SHA3 implementation which implements the standard hash.Hash interface.
-// Writing input data, including padding, and reading output data are computed in this file.
-// Note that the current implementation can compute the hash of an integral number of bytes only.
-// This is a consequence of the hash interface in which a buffer of bytes is passed in.
-// The internals of the Keccak-f function are computed in keccakf.go.
-// For the detailed specification, refer to the Keccak web site (http://keccak.noekeon.org/).
-package sha3
-
-import (
- "encoding/binary"
- "hash"
-)
-
-// laneSize is the size in bytes of each "lane" of the internal state of SHA3 (5 * 5 * 8).
-// Note that changing this size would requires using a type other than uint64 to store each lane.
-const laneSize = 8
-
-// sliceSize represents the dimensions of the internal state, a square matrix of
-// sliceSize ** 2 lanes. This is the size of both the "rows" and "columns" dimensions in the
-// terminology of the SHA3 specification.
-const sliceSize = 5
-
-// numLanes represents the total number of lanes in the state.
-const numLanes = sliceSize * sliceSize
-
-// stateSize is the size in bytes of the internal state of SHA3 (5 * 5 * WSize).
-const stateSize = laneSize * numLanes
-
-// digest represents the partial evaluation of a checksum.
-// Note that capacity, and not outputSize, is the critical security parameter, as SHA3 can output
-// an arbitrary number of bytes for any given capacity. The Keccak proposal recommends that
-// capacity = 2*outputSize to ensure that finding a collision of size outputSize requires
-// O(2^{outputSize/2}) computations (the birthday lower bound). Future standards may modify the
-// capacity/outputSize ratio to allow for more output with lower cryptographic security.
-type digest struct {
- a [numLanes]uint64 // main state of the hash
- outputSize int // desired output size in bytes
- capacity int // number of bytes to leave untouched during squeeze/absorb
- absorbed int // number of bytes absorbed thus far
-}
-
-// minInt returns the lesser of two integer arguments, to simplify the absorption routine.
-func minInt(v1, v2 int) int {
- if v1 <= v2 {
- return v1
- }
- return v2
-}
-
-// rate returns the number of bytes of the internal state which can be absorbed or squeezed
-// in between calls to the permutation function.
-func (d *digest) rate() int {
- return stateSize - d.capacity
-}
-
-// Reset clears the internal state by zeroing bytes in the state buffer.
-// This can be skipped for a newly-created hash state; the default zero-allocated state is correct.
-func (d *digest) Reset() {
- d.absorbed = 0
- for i := range d.a {
- d.a[i] = 0
- }
-}
-
-// BlockSize, required by the hash.Hash interface, does not have a standard intepretation
-// for a sponge-based construction like SHA3. We return the data rate: the number of bytes which
-// can be absorbed per invocation of the permutation function. For Merkle-Damgård based hashes
-// (ie SHA1, SHA2, MD5) the output size of the internal compression function is returned.
-// We consider this to be roughly equivalent because it represents the number of bytes of output
-// produced per cryptographic operation.
-func (d *digest) BlockSize() int { return d.rate() }
-
-// Size returns the output size of the hash function in bytes.
-func (d *digest) Size() int {
- return d.outputSize
-}
-
-// unalignedAbsorb is a helper function for Write, which absorbs data that isn't aligned with an
-// 8-byte lane. This requires shifting the individual bytes into position in a uint64.
-func (d *digest) unalignedAbsorb(p []byte) {
- var t uint64
- for i := len(p) - 1; i >= 0; i-- {
- t <<= 8
- t |= uint64(p[i])
- }
- offset := (d.absorbed) % d.rate()
- t <<= 8 * uint(offset%laneSize)
- d.a[offset/laneSize] ^= t
- d.absorbed += len(p)
-}
-
-// Write "absorbs" bytes into the state of the SHA3 hash, updating as needed when the sponge
-// "fills up" with rate() bytes. Since lanes are stored internally as type uint64, this requires
-// converting the incoming bytes into uint64s using a little endian interpretation. This
-// implementation is optimized for large, aligned writes of multiples of 8 bytes (laneSize).
-// Non-aligned or uneven numbers of bytes require shifting and are slower.
-func (d *digest) Write(p []byte) (int, error) {
- // An initial offset is needed if the we aren't absorbing to the first lane initially.
- offset := d.absorbed % d.rate()
- toWrite := len(p)
-
- // The first lane may need to absorb unaligned and/or incomplete data.
- if (offset%laneSize != 0 || len(p) < 8) && len(p) > 0 {
- toAbsorb := minInt(laneSize-(offset%laneSize), len(p))
- d.unalignedAbsorb(p[:toAbsorb])
- p = p[toAbsorb:]
- offset = (d.absorbed) % d.rate()
-
- // For every rate() bytes absorbed, the state must be permuted via the F Function.
- if (d.absorbed)%d.rate() == 0 {
- keccakF1600(&d.a)
- }
- }
-
- // This loop should absorb the bulk of the data into full, aligned lanes.
- // It will call the update function as necessary.
- for len(p) > 7 {
- firstLane := offset / laneSize
- lastLane := minInt(d.rate()/laneSize, firstLane+len(p)/laneSize)
-
- // This inner loop absorbs input bytes into the state in groups of 8, converted to uint64s.
- for lane := firstLane; lane < lastLane; lane++ {
- d.a[lane] ^= binary.LittleEndian.Uint64(p[:laneSize])
- p = p[laneSize:]
- }
- d.absorbed += (lastLane - firstLane) * laneSize
- // For every rate() bytes absorbed, the state must be permuted via the F Function.
- if (d.absorbed)%d.rate() == 0 {
- keccakF1600(&d.a)
- }
-
- offset = 0
- }
-
- // If there are insufficient bytes to fill the final lane, an unaligned absorption.
- // This should always start at a correct lane boundary though, or else it would be caught
- // by the uneven opening lane case above.
- if len(p) > 0 {
- d.unalignedAbsorb(p)
- }
-
- return toWrite, nil
-}
-
-// pad computes the SHA3 padding scheme based on the number of bytes absorbed.
-// The padding is a 1 bit, followed by an arbitrary number of 0s and then a final 1 bit, such that
-// the input bits plus padding bits are a multiple of rate(). Adding the padding simply requires
-// xoring an opening and closing bit into the appropriate lanes.
-func (d *digest) pad() {
- offset := d.absorbed % d.rate()
- // The opening pad bit must be shifted into position based on the number of bytes absorbed
- padOpenLane := offset / laneSize
- d.a[padOpenLane] ^= 0x0000000000000001 << uint(8*(offset%laneSize))
- // The closing padding bit is always in the last position
- padCloseLane := (d.rate() / laneSize) - 1
- d.a[padCloseLane] ^= 0x8000000000000000
-}
-
-// finalize prepares the hash to output data by padding and one final permutation of the state.
-func (d *digest) finalize() {
- d.pad()
- keccakF1600(&d.a)
-}
-
-// squeeze outputs an arbitrary number of bytes from the hash state.
-// Squeezing can require multiple calls to the F function (one per rate() bytes squeezed),
-// although this is not the case for standard SHA3 parameters. This implementation only supports
-// squeezing a single time, subsequent squeezes may lose alignment. Future implementations
-// may wish to support multiple squeeze calls, for example to support use as a PRNG.
-func (d *digest) squeeze(in []byte, toSqueeze int) []byte {
- // Because we read in blocks of laneSize, we need enough room to read
- // an integral number of lanes
- needed := toSqueeze + (laneSize-toSqueeze%laneSize)%laneSize
- if cap(in)-len(in) < needed {
- newIn := make([]byte, len(in), len(in)+needed)
- copy(newIn, in)
- in = newIn
- }
- out := in[len(in) : len(in)+needed]
-
- for len(out) > 0 {
- for i := 0; i < d.rate() && len(out) > 0; i += laneSize {
- binary.LittleEndian.PutUint64(out[:], d.a[i/laneSize])
- out = out[laneSize:]
- }
- if len(out) > 0 {
- keccakF1600(&d.a)
- }
- }
- return in[:len(in)+toSqueeze] // Re-slice in case we wrote extra data.
-}
-
-// Sum applies padding to the hash state and then squeezes out the desired nubmer of output bytes.
-func (d *digest) Sum(in []byte) []byte {
- // Make a copy of the original hash so that caller can keep writing and summing.
- dup := *d
- dup.finalize()
- return dup.squeeze(in, dup.outputSize)
-}
-
-// The NewKeccakX constructors enable initializing a hash in any of the four recommend sizes
-// from the Keccak specification, all of which set capacity=2*outputSize. Note that the final
-// NIST standard for SHA3 may specify different input/output lengths.
-// The output size is indicated in bits but converted into bytes internally.
-func NewKeccak224() hash.Hash { return &digest{outputSize: 224 / 8, capacity: 2 * 224 / 8} }
-func NewKeccak256() hash.Hash { return &digest{outputSize: 256 / 8, capacity: 2 * 256 / 8} }
-func NewKeccak384() hash.Hash { return &digest{outputSize: 384 / 8, capacity: 2 * 384 / 8} }
-func NewKeccak512() hash.Hash { return &digest{outputSize: 512 / 8, capacity: 2 * 512 / 8} }