diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/blake2s/blake2s.go')
-rw-r--r-- | vendor/golang.org/x/crypto/blake2s/blake2s.go | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/blake2s/blake2s.go b/vendor/golang.org/x/crypto/blake2s/blake2s.go new file mode 100644 index 0000000..ae0dc92 --- /dev/null +++ b/vendor/golang.org/x/crypto/blake2s/blake2s.go @@ -0,0 +1,187 @@ +// Copyright 2016 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package blake2s implements the BLAKE2s hash algorithm defined by RFC 7693 +// and the extendable output function (XOF) BLAKE2Xs. +// +// For a detailed specification of BLAKE2s see https://blake2.net/blake2.pdf +// and for BLAKE2Xs see https://blake2.net/blake2x.pdf +// +// If you aren't sure which function you need, use BLAKE2s (Sum256 or New256). +// If you need a secret-key MAC (message authentication code), use the New256 +// function with a non-nil key. +// +// BLAKE2X is a construction to compute hash values larger than 32 bytes. It +// can produce hash values between 0 and 65535 bytes. +package blake2s // import "golang.org/x/crypto/blake2s" + +import ( + "encoding/binary" + "errors" + "hash" +) + +const ( + // The blocksize of BLAKE2s in bytes. + BlockSize = 64 + + // The hash size of BLAKE2s-256 in bytes. + Size = 32 + + // The hash size of BLAKE2s-128 in bytes. + Size128 = 16 +) + +var errKeySize = errors.New("blake2s: invalid key size") + +var iv = [8]uint32{ + 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, + 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19, +} + +// Sum256 returns the BLAKE2s-256 checksum of the data. +func Sum256(data []byte) [Size]byte { + var sum [Size]byte + checkSum(&sum, Size, data) + return sum +} + +// New256 returns a new hash.Hash computing the BLAKE2s-256 checksum. A non-nil +// key turns the hash into a MAC. The key must between zero and 32 bytes long. +func New256(key []byte) (hash.Hash, error) { return newDigest(Size, key) } + +// New128 returns a new hash.Hash computing the BLAKE2s-128 checksum given a +// non-empty key. Note that a 128-bit digest is too small to be secure as a +// cryptographic hash and should only be used as a MAC, thus the key argument +// is not optional. +func New128(key []byte) (hash.Hash, error) { + if len(key) == 0 { + return nil, errors.New("blake2s: a key is required for a 128-bit hash") + } + return newDigest(Size128, key) +} + +func newDigest(hashSize int, key []byte) (*digest, error) { + if len(key) > Size { + return nil, errKeySize + } + d := &digest{ + size: hashSize, + keyLen: len(key), + } + copy(d.key[:], key) + d.Reset() + return d, nil +} + +func checkSum(sum *[Size]byte, hashSize int, data []byte) { + var ( + h [8]uint32 + c [2]uint32 + ) + + h = iv + h[0] ^= uint32(hashSize) | (1 << 16) | (1 << 24) + + if length := len(data); length > BlockSize { + n := length &^ (BlockSize - 1) + if length == n { + n -= BlockSize + } + hashBlocks(&h, &c, 0, data[:n]) + data = data[n:] + } + + var block [BlockSize]byte + offset := copy(block[:], data) + remaining := uint32(BlockSize - offset) + + if c[0] < remaining { + c[1]-- + } + c[0] -= remaining + + hashBlocks(&h, &c, 0xFFFFFFFF, block[:]) + + for i, v := range h { + binary.LittleEndian.PutUint32(sum[4*i:], v) + } +} + +type digest struct { + h [8]uint32 + c [2]uint32 + size int + block [BlockSize]byte + offset int + + key [BlockSize]byte + keyLen int +} + +func (d *digest) BlockSize() int { return BlockSize } + +func (d *digest) Size() int { return d.size } + +func (d *digest) Reset() { + d.h = iv + d.h[0] ^= uint32(d.size) | (uint32(d.keyLen) << 8) | (1 << 16) | (1 << 24) + d.offset, d.c[0], d.c[1] = 0, 0, 0 + if d.keyLen > 0 { + d.block = d.key + d.offset = BlockSize + } +} + +func (d *digest) Write(p []byte) (n int, err error) { + n = len(p) + + if d.offset > 0 { + remaining := BlockSize - d.offset + if n <= remaining { + d.offset += copy(d.block[d.offset:], p) + return + } + copy(d.block[d.offset:], p[:remaining]) + hashBlocks(&d.h, &d.c, 0, d.block[:]) + d.offset = 0 + p = p[remaining:] + } + + if length := len(p); length > BlockSize { + nn := length &^ (BlockSize - 1) + if length == nn { + nn -= BlockSize + } + hashBlocks(&d.h, &d.c, 0, p[:nn]) + p = p[nn:] + } + + d.offset += copy(d.block[:], p) + return +} + +func (d *digest) Sum(sum []byte) []byte { + var hash [Size]byte + d.finalize(&hash) + return append(sum, hash[:d.size]...) +} + +func (d *digest) finalize(hash *[Size]byte) { + var block [BlockSize]byte + h := d.h + c := d.c + + copy(block[:], d.block[:d.offset]) + remaining := uint32(BlockSize - d.offset) + if c[0] < remaining { + c[1]-- + } + c[0] -= remaining + + hashBlocks(&h, &c, 0xFFFFFFFF, block[:]) + for i, v := range h { + binary.LittleEndian.PutUint32(hash[4*i:], v) + } +} |