Move to vendor

Signed-off-by: Olivier Gambier <olivier@docker.com>

vendor/github.com/stevvooe/resumable/sha512/sha512.go

@@ -0,0 +1,198 @@
+// Copyright 2009 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 sha512 implements the SHA384 and SHA512 hash algorithms as defined
+// in FIPS 180-2.
+package sha512
+
+import (
+	"crypto"
+	"hash"
+)
+
+func init() {
+	crypto.RegisterHash(crypto.SHA384, New384)
+	crypto.RegisterHash(crypto.SHA512, New)
+}
+
+// The size of a SHA512 checksum in bytes.
+const Size = 64
+
+// The size of a SHA384 checksum in bytes.
+const Size384 = 48
+
+// The blocksize of SHA512 and SHA384 in bytes.
+const BlockSize = 128
+
+const (
+	chunk     = 128
+	init0     = 0x6a09e667f3bcc908
+	init1     = 0xbb67ae8584caa73b
+	init2     = 0x3c6ef372fe94f82b
+	init3     = 0xa54ff53a5f1d36f1
+	init4     = 0x510e527fade682d1
+	init5     = 0x9b05688c2b3e6c1f
+	init6     = 0x1f83d9abfb41bd6b
+	init7     = 0x5be0cd19137e2179
+	init0_384 = 0xcbbb9d5dc1059ed8
+	init1_384 = 0x629a292a367cd507
+	init2_384 = 0x9159015a3070dd17
+	init3_384 = 0x152fecd8f70e5939
+	init4_384 = 0x67332667ffc00b31
+	init5_384 = 0x8eb44a8768581511
+	init6_384 = 0xdb0c2e0d64f98fa7
+	init7_384 = 0x47b5481dbefa4fa4
+)
+
+// digest represents the partial evaluation of a checksum.
+type digest struct {
+	h     [8]uint64
+	x     [chunk]byte
+	nx    int
+	len   uint64
+	is384 bool // mark if this digest is SHA-384
+}
+
+func (d *digest) Reset() {
+	if !d.is384 {
+		d.h[0] = init0
+		d.h[1] = init1
+		d.h[2] = init2
+		d.h[3] = init3
+		d.h[4] = init4
+		d.h[5] = init5
+		d.h[6] = init6
+		d.h[7] = init7
+	} else {
+		d.h[0] = init0_384
+		d.h[1] = init1_384
+		d.h[2] = init2_384
+		d.h[3] = init3_384
+		d.h[4] = init4_384
+		d.h[5] = init5_384
+		d.h[6] = init6_384
+		d.h[7] = init7_384
+	}
+	d.nx = 0
+	d.len = 0
+}
+
+// New returns a new hash.Hash computing the SHA512 checksum.
+func New() hash.Hash {
+	d := new(digest)
+	d.Reset()
+	return d
+}
+
+// New384 returns a new hash.Hash computing the SHA384 checksum.
+func New384() hash.Hash {
+	d := new(digest)
+	d.is384 = true
+	d.Reset()
+	return d
+}
+
+func (d *digest) Size() int {
+	if !d.is384 {
+		return Size
+	}
+	return Size384
+}
+
+func (d *digest) BlockSize() int { return BlockSize }
+
+func (d *digest) Write(p []byte) (nn int, err error) {
+	nn = len(p)
+	d.len += uint64(nn)
+	if d.nx > 0 {
+		n := copy(d.x[d.nx:], p)
+		d.nx += n
+		if d.nx == chunk {
+			block(d, d.x[:])
+			d.nx = 0
+		}
+		p = p[n:]
+	}
+	if len(p) >= chunk {
+		n := len(p) &^ (chunk - 1)
+		block(d, p[:n])
+		p = p[n:]
+	}
+	if len(p) > 0 {
+		d.nx = copy(d.x[:], p)
+	}
+	return
+}
+
+func (d0 *digest) Sum(in []byte) []byte {
+	// Make a copy of d0 so that caller can keep writing and summing.
+	d := new(digest)
+	*d = *d0
+	hash := d.checkSum()
+	if d.is384 {
+		return append(in, hash[:Size384]...)
+	}
+	return append(in, hash[:]...)
+}
+
+func (d *digest) checkSum() [Size]byte {
+	// Padding.  Add a 1 bit and 0 bits until 112 bytes mod 128.
+	len := d.len
+	var tmp [128]byte
+	tmp[0] = 0x80
+	if len%128 < 112 {
+		d.Write(tmp[0 : 112-len%128])
+	} else {
+		d.Write(tmp[0 : 128+112-len%128])
+	}
+
+	// Length in bits.
+	len <<= 3
+	for i := uint(0); i < 16; i++ {
+		tmp[i] = byte(len >> (120 - 8*i))
+	}
+	d.Write(tmp[0:16])
+
+	if d.nx != 0 {
+		panic("d.nx != 0")
+	}
+
+	h := d.h[:]
+	if d.is384 {
+		h = d.h[:6]
+	}
+
+	var digest [Size]byte
+	for i, s := range h {
+		digest[i*8] = byte(s >> 56)
+		digest[i*8+1] = byte(s >> 48)
+		digest[i*8+2] = byte(s >> 40)
+		digest[i*8+3] = byte(s >> 32)
+		digest[i*8+4] = byte(s >> 24)
+		digest[i*8+5] = byte(s >> 16)
+		digest[i*8+6] = byte(s >> 8)
+		digest[i*8+7] = byte(s)
+	}
+
+	return digest
+}
+
+// Sum512 returns the SHA512 checksum of the data.
+func Sum512(data []byte) [Size]byte {
+	var d digest
+	d.Reset()
+	d.Write(data)
+	return d.checkSum()
+}
+
+// Sum384 returns the SHA384 checksum of the data.
+func Sum384(data []byte) (sum384 [Size384]byte) {
+	var d digest
+	d.is384 = true
+	d.Reset()
+	d.Write(data)
+	sum := d.checkSum()
+	copy(sum384[:], sum[:Size384])
+	return
+}