/usr/share/gocode/src/github.com/dchest/blake2b/blake2b.go is in golang-github-dchest-blake2b-dev 0.0~git20170307.0.060063-1-1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 | // Written in 2012 by Dmitry Chestnykh.
//
// To the extent possible under law, the author have dedicated all copyright
// and related and neighboring rights to this software to the public domain
// worldwide. This software is distributed without any warranty.
// http://creativecommons.org/publicdomain/zero/1.0/
// Package blake2b implements BLAKE2b cryptographic hash function.
package blake2b
import (
"encoding/binary"
"errors"
"hash"
)
const (
BlockSize = 128 // block size of algorithm
Size = 64 // maximum digest size
SaltSize = 16 // maximum salt size
PersonSize = 16 // maximum personalization string size
KeySize = 64 // maximum size of key
)
type digest struct {
h [8]uint64 // current chain value
t [2]uint64 // message bytes counter
f [2]uint64 // finalization flags
x [BlockSize]byte // buffer for data not yet compressed
nx int // number of bytes in buffer
ih [8]uint64 // initial chain value (after config)
paddedKey [BlockSize]byte // copy of key, padded with zeros
isKeyed bool // indicates whether hash was keyed
size uint8 // digest size in bytes
isLastNode bool // indicates processing of the last node in tree hashing
}
// Initialization values.
var iv = [8]uint64{
0x6a09e667f3bcc908, 0xbb67ae8584caa73b,
0x3c6ef372fe94f82b, 0xa54ff53a5f1d36f1,
0x510e527fade682d1, 0x9b05688c2b3e6c1f,
0x1f83d9abfb41bd6b, 0x5be0cd19137e2179,
}
// Config is used to configure hash function parameters and keying.
// All parameters are optional.
type Config struct {
Size uint8 // digest size (if zero, default size of 64 bytes is used)
Key []byte // key for prefix-MAC
Salt []byte // salt (if < 16 bytes, padded with zeros)
Person []byte // personalization (if < 16 bytes, padded with zeros)
Tree *Tree // parameters for tree hashing
}
// Tree represents parameters for tree hashing.
type Tree struct {
Fanout uint8 // fanout
MaxDepth uint8 // maximal depth
LeafSize uint32 // leaf maximal byte length (0 for unlimited)
NodeOffset uint64 // node offset (0 for first, leftmost or leaf)
NodeDepth uint8 // node depth (0 for leaves)
InnerHashSize uint8 // inner hash byte length
IsLastNode bool // indicates processing of the last node of layer
}
var (
defaultConfig = &Config{Size: Size}
config256 = &Config{Size: 32}
)
func verifyConfig(c *Config) error {
if c.Size > Size {
return errors.New("digest size is too large")
}
if len(c.Key) > KeySize {
return errors.New("key is too large")
}
if len(c.Salt) > SaltSize {
// Smaller salt is okay: it will be padded with zeros.
return errors.New("salt is too large")
}
if len(c.Person) > PersonSize {
// Smaller personalization is okay: it will be padded with zeros.
return errors.New("personalization is too large")
}
if c.Tree != nil {
if c.Tree.InnerHashSize > Size {
return errors.New("incorrect tree inner hash size")
}
}
return nil
}
// New returns a new hash.Hash configured with the given Config.
// Config can be nil, in which case the default one is used, calculating 64-byte digest.
// Returns non-nil error if Config contains invalid parameters.
func New(c *Config) (hash.Hash, error) {
if c == nil {
c = defaultConfig
} else {
if c.Size == 0 {
// Set default size if it's zero.
c.Size = Size
}
if err := verifyConfig(c); err != nil {
return nil, err
}
}
d := new(digest)
d.initialize(c)
return d, nil
}
// initialize initializes digest with the given
// config, which must be non-nil and verified.
func (d *digest) initialize(c *Config) {
// Create parameter block.
var p [BlockSize]byte
p[0] = c.Size
p[1] = uint8(len(c.Key))
if c.Salt != nil {
copy(p[32:], c.Salt)
}
if c.Person != nil {
copy(p[48:], c.Person)
}
if c.Tree != nil {
p[2] = c.Tree.Fanout
p[3] = c.Tree.MaxDepth
binary.LittleEndian.PutUint32(p[4:], c.Tree.LeafSize)
binary.LittleEndian.PutUint64(p[8:], c.Tree.NodeOffset)
p[16] = c.Tree.NodeDepth
p[17] = c.Tree.InnerHashSize
} else {
p[2] = 1
p[3] = 1
}
// Initialize.
d.size = c.Size
for i := 0; i < 8; i++ {
d.h[i] = iv[i] ^ binary.LittleEndian.Uint64(p[i*8:])
}
if c.Tree != nil && c.Tree.IsLastNode {
d.isLastNode = true
}
// Process key.
if len(c.Key) > 0 {
copy(d.paddedKey[:], c.Key)
d.Write(d.paddedKey[:])
d.isKeyed = true
}
// Save a copy of initialized state.
copy(d.ih[:], d.h[:])
}
// New512 returns a new hash.Hash computing the BLAKE2b 64-byte checksum.
func New512() hash.Hash {
d := new(digest)
d.initialize(defaultConfig)
return d
}
// New256 returns a new hash.Hash computing the BLAKE2b 32-byte checksum.
func New256() hash.Hash {
d := new(digest)
d.initialize(config256)
return d
}
// NewMAC returns a new hash.Hash computing BLAKE2b prefix-
// Message Authentication Code of the given size in bytes
// (up to 64) with the given key (up to 64 bytes in length).
func NewMAC(outBytes uint8, key []byte) hash.Hash {
d, err := New(&Config{Size: outBytes, Key: key})
if err != nil {
panic(err.Error())
}
return d
}
// Reset resets the state of digest to the initial state
// after configuration and keying.
func (d *digest) Reset() {
copy(d.h[:], d.ih[:])
d.t[0] = 0
d.t[1] = 0
d.f[0] = 0
d.f[1] = 0
d.nx = 0
if d.isKeyed {
d.Write(d.paddedKey[:])
}
}
// Size returns the digest size in bytes.
func (d *digest) Size() int { return int(d.size) }
// BlockSize returns the algorithm block size in bytes.
func (d *digest) BlockSize() int { return BlockSize }
func (d *digest) Write(p []byte) (nn int, err error) {
nn = len(p)
left := BlockSize - d.nx
if len(p) > left {
// Process buffer.
copy(d.x[d.nx:], p[:left])
p = p[left:]
blocks(d, d.x[:])
d.nx = 0
}
// Process full blocks except for the last one.
if len(p) > BlockSize {
n := len(p) &^ (BlockSize - 1)
if n == len(p) {
n -= BlockSize
}
blocks(d, p[:n])
p = p[n:]
}
// Fill buffer.
d.nx += copy(d.x[d.nx:], p)
return
}
// Sum returns the calculated checksum.
func (d0 *digest) Sum(in []byte) []byte {
// Make a copy of d0 so that caller can keep writing and summing.
d := *d0
hash := d.checkSum()
return append(in, hash[:d.size]...)
}
func (d *digest) checkSum() [Size]byte {
// Do not create unnecessary copies of the key.
if d.isKeyed {
for i := 0; i < len(d.paddedKey); i++ {
d.paddedKey[i] = 0
}
}
dec := BlockSize - uint64(d.nx)
if d.t[0] < dec {
d.t[1]--
}
d.t[0] -= dec
// Pad buffer with zeros.
for i := d.nx; i < len(d.x); i++ {
d.x[i] = 0
}
// Set last block flag.
d.f[0] = 0xffffffffffffffff
if d.isLastNode {
d.f[1] = 0xffffffffffffffff
}
// Compress last block.
blocks(d, d.x[:])
var out [Size]byte
j := 0
for _, s := range d.h[:(d.size-1)/8+1] {
out[j+0] = byte(s >> 0)
out[j+1] = byte(s >> 8)
out[j+2] = byte(s >> 16)
out[j+3] = byte(s >> 24)
out[j+4] = byte(s >> 32)
out[j+5] = byte(s >> 40)
out[j+6] = byte(s >> 48)
out[j+7] = byte(s >> 56)
j += 8
}
return out
}
// Sum512 returns a 64-byte BLAKE2b hash of data.
func Sum512(data []byte) [64]byte {
var d digest
d.initialize(defaultConfig)
d.Write(data)
return d.checkSum()
}
// Sum256 returns a 32-byte BLAKE2b hash of data.
func Sum256(data []byte) (out [32]byte) {
var d digest
d.initialize(config256)
d.Write(data)
sum := d.checkSum()
copy(out[:], sum[:32])
return
}
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