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Source file src/crypto/sha512/sha512.go

Documentation: crypto/sha512

  // 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 SHA-384, SHA-512, SHA-512/224, and SHA-512/256
  // hash algorithms as defined in FIPS 180-4.
  package sha512
  
  import (
  	"crypto"
  	"hash"
  )
  
  func init() {
  	crypto.RegisterHash(crypto.SHA384, New384)
  	crypto.RegisterHash(crypto.SHA512, New)
  	crypto.RegisterHash(crypto.SHA512_224, New512_224)
  	crypto.RegisterHash(crypto.SHA512_256, New512_256)
  }
  
  const (
  	// Size is the size, in bytes, of a SHA-512 checksum.
  	Size = 64
  
  	// Size224 is the size, in bytes, of a SHA-512/224 checksum.
  	Size224 = 28
  
  	// Size256 is the size, in bytes, of a SHA-512/256 checksum.
  	Size256 = 32
  
  	// Size384 is the size, in bytes, of a SHA-384 checksum.
  	Size384 = 48
  
  	// BlockSize is the block size, in bytes, of the SHA-512/224,
  	// SHA-512/256, SHA-384 and SHA-512 hash functions.
  	BlockSize = 128
  )
  
  const (
  	chunk     = 128
  	init0     = 0x6a09e667f3bcc908
  	init1     = 0xbb67ae8584caa73b
  	init2     = 0x3c6ef372fe94f82b
  	init3     = 0xa54ff53a5f1d36f1
  	init4     = 0x510e527fade682d1
  	init5     = 0x9b05688c2b3e6c1f
  	init6     = 0x1f83d9abfb41bd6b
  	init7     = 0x5be0cd19137e2179
  	init0_224 = 0x8c3d37c819544da2
  	init1_224 = 0x73e1996689dcd4d6
  	init2_224 = 0x1dfab7ae32ff9c82
  	init3_224 = 0x679dd514582f9fcf
  	init4_224 = 0x0f6d2b697bd44da8
  	init5_224 = 0x77e36f7304c48942
  	init6_224 = 0x3f9d85a86a1d36c8
  	init7_224 = 0x1112e6ad91d692a1
  	init0_256 = 0x22312194fc2bf72c
  	init1_256 = 0x9f555fa3c84c64c2
  	init2_256 = 0x2393b86b6f53b151
  	init3_256 = 0x963877195940eabd
  	init4_256 = 0x96283ee2a88effe3
  	init5_256 = 0xbe5e1e2553863992
  	init6_256 = 0x2b0199fc2c85b8aa
  	init7_256 = 0x0eb72ddc81c52ca2
  	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
  	function crypto.Hash
  }
  
  func (d *digest) Reset() {
  	switch d.function {
  	case crypto.SHA384:
  		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
  	case crypto.SHA512_224:
  		d.h[0] = init0_224
  		d.h[1] = init1_224
  		d.h[2] = init2_224
  		d.h[3] = init3_224
  		d.h[4] = init4_224
  		d.h[5] = init5_224
  		d.h[6] = init6_224
  		d.h[7] = init7_224
  	case crypto.SHA512_256:
  		d.h[0] = init0_256
  		d.h[1] = init1_256
  		d.h[2] = init2_256
  		d.h[3] = init3_256
  		d.h[4] = init4_256
  		d.h[5] = init5_256
  		d.h[6] = init6_256
  		d.h[7] = init7_256
  	default:
  		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
  	}
  	d.nx = 0
  	d.len = 0
  }
  
  // New returns a new hash.Hash computing the SHA-512 checksum.
  func New() hash.Hash {
  	d := &digest{function: crypto.SHA512}
  	d.Reset()
  	return d
  }
  
  // New512_224 returns a new hash.Hash computing the SHA-512/224 checksum.
  func New512_224() hash.Hash {
  	d := &digest{function: crypto.SHA512_224}
  	d.Reset()
  	return d
  }
  
  // New512_256 returns a new hash.Hash computing the SHA-512/256 checksum.
  func New512_256() hash.Hash {
  	d := &digest{function: crypto.SHA512_256}
  	d.Reset()
  	return d
  }
  
  // New384 returns a new hash.Hash computing the SHA-384 checksum.
  func New384() hash.Hash {
  	d := &digest{function: crypto.SHA384}
  	d.Reset()
  	return d
  }
  
  func (d *digest) Size() int {
  	switch d.function {
  	case crypto.SHA512_224:
  		return Size224
  	case crypto.SHA512_256:
  		return Size256
  	case crypto.SHA384:
  		return Size384
  	default:
  		return Size
  	}
  }
  
  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()
  	switch d.function {
  	case crypto.SHA384:
  		return append(in, hash[:Size384]...)
  	case crypto.SHA512_224:
  		return append(in, hash[:Size224]...)
  	case crypto.SHA512_256:
  		return append(in, hash[:Size256]...)
  	default:
  		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.function == crypto.SHA384 {
  		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 {
  	d := digest{function: crypto.SHA512}
  	d.Reset()
  	d.Write(data)
  	return d.checkSum()
  }
  
  // Sum384 returns the SHA384 checksum of the data.
  func Sum384(data []byte) (sum384 [Size384]byte) {
  	d := digest{function: crypto.SHA384}
  	d.Reset()
  	d.Write(data)
  	sum := d.checkSum()
  	copy(sum384[:], sum[:Size384])
  	return
  }
  
  // Sum512_224 returns the Sum512/224 checksum of the data.
  func Sum512_224(data []byte) (sum224 [Size224]byte) {
  	d := digest{function: crypto.SHA512_224}
  	d.Reset()
  	d.Write(data)
  	sum := d.checkSum()
  	copy(sum224[:], sum[:Size224])
  	return
  }
  
  // Sum512_256 returns the Sum512/256 checksum of the data.
  func Sum512_256(data []byte) (sum256 [Size256]byte) {
  	d := digest{function: crypto.SHA512_256}
  	d.Reset()
  	d.Write(data)
  	sum := d.checkSum()
  	copy(sum256[:], sum[:Size256])
  	return
  }
  

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