sha512.go

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Package sha512 implements the SHA-384, SHA-512, SHA-512/224, and SHA-512/256
     6  // hash algorithms as defined in FIPS 180-4.
     7  package sha512
     8  
     9  import (
    10  	"crypto/internal/fips"
    11  	"errors"
    12  	"internal/byteorder"
    13  )
    14  
    15  const (
    16  	// size512 is the size, in bytes, of a SHA-512 checksum.
    17  	size512 = 64
    18  
    19  	// size224 is the size, in bytes, of a SHA-512/224 checksum.
    20  	size224 = 28
    21  
    22  	// size256 is the size, in bytes, of a SHA-512/256 checksum.
    23  	size256 = 32
    24  
    25  	// size384 is the size, in bytes, of a SHA-384 checksum.
    26  	size384 = 48
    27  
    28  	// blockSize is the block size, in bytes, of the SHA-512/224,
    29  	// SHA-512/256, SHA-384 and SHA-512 hash functions.
    30  	blockSize = 128
    31  )
    32  
    33  const (
    34  	chunk     = 128
    35  	init0     = 0x6a09e667f3bcc908
    36  	init1     = 0xbb67ae8584caa73b
    37  	init2     = 0x3c6ef372fe94f82b
    38  	init3     = 0xa54ff53a5f1d36f1
    39  	init4     = 0x510e527fade682d1
    40  	init5     = 0x9b05688c2b3e6c1f
    41  	init6     = 0x1f83d9abfb41bd6b
    42  	init7     = 0x5be0cd19137e2179
    43  	init0_224 = 0x8c3d37c819544da2
    44  	init1_224 = 0x73e1996689dcd4d6
    45  	init2_224 = 0x1dfab7ae32ff9c82
    46  	init3_224 = 0x679dd514582f9fcf
    47  	init4_224 = 0x0f6d2b697bd44da8
    48  	init5_224 = 0x77e36f7304c48942
    49  	init6_224 = 0x3f9d85a86a1d36c8
    50  	init7_224 = 0x1112e6ad91d692a1
    51  	init0_256 = 0x22312194fc2bf72c
    52  	init1_256 = 0x9f555fa3c84c64c2
    53  	init2_256 = 0x2393b86b6f53b151
    54  	init3_256 = 0x963877195940eabd
    55  	init4_256 = 0x96283ee2a88effe3
    56  	init5_256 = 0xbe5e1e2553863992
    57  	init6_256 = 0x2b0199fc2c85b8aa
    58  	init7_256 = 0x0eb72ddc81c52ca2
    59  	init0_384 = 0xcbbb9d5dc1059ed8
    60  	init1_384 = 0x629a292a367cd507
    61  	init2_384 = 0x9159015a3070dd17
    62  	init3_384 = 0x152fecd8f70e5939
    63  	init4_384 = 0x67332667ffc00b31
    64  	init5_384 = 0x8eb44a8768581511
    65  	init6_384 = 0xdb0c2e0d64f98fa7
    66  	init7_384 = 0x47b5481dbefa4fa4
    67  )
    68  
    69  // Digest is a SHA-384, SHA-512, SHA-512/224, or SHA-512/256 [hash.Hash]
    70  // implementation.
    71  type Digest struct {
    72  	h    [8]uint64
    73  	x    [chunk]byte
    74  	nx   int
    75  	len  uint64
    76  	size int // size224, size256, size384, or size512
    77  }
    78  
    79  func (d *Digest) Reset() {
    80  	switch d.size {
    81  	case size384:
    82  		d.h[0] = init0_384
    83  		d.h[1] = init1_384
    84  		d.h[2] = init2_384
    85  		d.h[3] = init3_384
    86  		d.h[4] = init4_384
    87  		d.h[5] = init5_384
    88  		d.h[6] = init6_384
    89  		d.h[7] = init7_384
    90  	case size224:
    91  		d.h[0] = init0_224
    92  		d.h[1] = init1_224
    93  		d.h[2] = init2_224
    94  		d.h[3] = init3_224
    95  		d.h[4] = init4_224
    96  		d.h[5] = init5_224
    97  		d.h[6] = init6_224
    98  		d.h[7] = init7_224
    99  	case size256:
   100  		d.h[0] = init0_256
   101  		d.h[1] = init1_256
   102  		d.h[2] = init2_256
   103  		d.h[3] = init3_256
   104  		d.h[4] = init4_256
   105  		d.h[5] = init5_256
   106  		d.h[6] = init6_256
   107  		d.h[7] = init7_256
   108  	case size512:
   109  		d.h[0] = init0
   110  		d.h[1] = init1
   111  		d.h[2] = init2
   112  		d.h[3] = init3
   113  		d.h[4] = init4
   114  		d.h[5] = init5
   115  		d.h[6] = init6
   116  		d.h[7] = init7
   117  	default:
   118  		panic("unknown size")
   119  	}
   120  	d.nx = 0
   121  	d.len = 0
   122  }
   123  
   124  const (
   125  	magic384      = "sha\x04"
   126  	magic512_224  = "sha\x05"
   127  	magic512_256  = "sha\x06"
   128  	magic512      = "sha\x07"
   129  	marshaledSize = len(magic512) + 8*8 + chunk + 8
   130  )
   131  
   132  func (d *Digest) MarshalBinary() ([]byte, error) {
   133  	return d.AppendBinary(make([]byte, 0, marshaledSize))
   134  }
   135  
   136  func (d *Digest) AppendBinary(b []byte) ([]byte, error) {
   137  	switch d.size {
   138  	case size384:
   139  		b = append(b, magic384...)
   140  	case size224:
   141  		b = append(b, magic512_224...)
   142  	case size256:
   143  		b = append(b, magic512_256...)
   144  	case size512:
   145  		b = append(b, magic512...)
   146  	default:
   147  		panic("unknown size")
   148  	}
   149  	b = byteorder.BeAppendUint64(b, d.h[0])
   150  	b = byteorder.BeAppendUint64(b, d.h[1])
   151  	b = byteorder.BeAppendUint64(b, d.h[2])
   152  	b = byteorder.BeAppendUint64(b, d.h[3])
   153  	b = byteorder.BeAppendUint64(b, d.h[4])
   154  	b = byteorder.BeAppendUint64(b, d.h[5])
   155  	b = byteorder.BeAppendUint64(b, d.h[6])
   156  	b = byteorder.BeAppendUint64(b, d.h[7])
   157  	b = append(b, d.x[:d.nx]...)
   158  	b = append(b, make([]byte, len(d.x)-d.nx)...)
   159  	b = byteorder.BeAppendUint64(b, d.len)
   160  	return b, nil
   161  }
   162  
   163  func (d *Digest) UnmarshalBinary(b []byte) error {
   164  	if len(b) < len(magic512) {
   165  		return errors.New("crypto/sha512: invalid hash state identifier")
   166  	}
   167  	switch {
   168  	case d.size == size384 && string(b[:len(magic384)]) == magic384:
   169  	case d.size == size224 && string(b[:len(magic512_224)]) == magic512_224:
   170  	case d.size == size256 && string(b[:len(magic512_256)]) == magic512_256:
   171  	case d.size == size512 && string(b[:len(magic512)]) == magic512:
   172  	default:
   173  		return errors.New("crypto/sha512: invalid hash state identifier")
   174  	}
   175  	if len(b) != marshaledSize {
   176  		return errors.New("crypto/sha512: invalid hash state size")
   177  	}
   178  	b = b[len(magic512):]
   179  	b, d.h[0] = consumeUint64(b)
   180  	b, d.h[1] = consumeUint64(b)
   181  	b, d.h[2] = consumeUint64(b)
   182  	b, d.h[3] = consumeUint64(b)
   183  	b, d.h[4] = consumeUint64(b)
   184  	b, d.h[5] = consumeUint64(b)
   185  	b, d.h[6] = consumeUint64(b)
   186  	b, d.h[7] = consumeUint64(b)
   187  	b = b[copy(d.x[:], b):]
   188  	b, d.len = consumeUint64(b)
   189  	d.nx = int(d.len % chunk)
   190  	return nil
   191  }
   192  
   193  func consumeUint64(b []byte) ([]byte, uint64) {
   194  	return b[8:], byteorder.BeUint64(b)
   195  }
   196  
   197  // New returns a new Digest computing the SHA-512 hash.
   198  func New() *Digest {
   199  	d := &Digest{size: size512}
   200  	d.Reset()
   201  	return d
   202  }
   203  
   204  // New512_224 returns a new Digest computing the SHA-512/224 hash.
   205  func New512_224() *Digest {
   206  	d := &Digest{size: size224}
   207  	d.Reset()
   208  	return d
   209  }
   210  
   211  // New512_256 returns a new Digest computing the SHA-512/256 hash.
   212  func New512_256() *Digest {
   213  	d := &Digest{size: size256}
   214  	d.Reset()
   215  	return d
   216  }
   217  
   218  // New384 returns a new Digest computing the SHA-384 hash.
   219  func New384() *Digest {
   220  	d := &Digest{size: size384}
   221  	d.Reset()
   222  	return d
   223  }
   224  
   225  func (d *Digest) Size() int {
   226  	return d.size
   227  }
   228  
   229  func (d *Digest) BlockSize() int { return blockSize }
   230  
   231  func (d *Digest) Write(p []byte) (nn int, err error) {
   232  	nn = len(p)
   233  	d.len += uint64(nn)
   234  	if d.nx > 0 {
   235  		n := copy(d.x[d.nx:], p)
   236  		d.nx += n
   237  		if d.nx == chunk {
   238  			block(d, d.x[:])
   239  			d.nx = 0
   240  		}
   241  		p = p[n:]
   242  	}
   243  	if len(p) >= chunk {
   244  		n := len(p) &^ (chunk - 1)
   245  		block(d, p[:n])
   246  		p = p[n:]
   247  	}
   248  	if len(p) > 0 {
   249  		d.nx = copy(d.x[:], p)
   250  	}
   251  	return
   252  }
   253  
   254  func (d *Digest) Sum(in []byte) []byte {
   255  	fips.RecordApproved()
   256  	// Make a copy of d so that caller can keep writing and summing.
   257  	d0 := new(Digest)
   258  	*d0 = *d
   259  	hash := d0.checkSum()
   260  	return append(in, hash[:d.size]...)
   261  }
   262  
   263  func (d *Digest) checkSum() [size512]byte {
   264  	// Padding. Add a 1 bit and 0 bits until 112 bytes mod 128.
   265  	len := d.len
   266  	var tmp [128 + 16]byte // padding + length buffer
   267  	tmp[0] = 0x80
   268  	var t uint64
   269  	if len%128 < 112 {
   270  		t = 112 - len%128
   271  	} else {
   272  		t = 128 + 112 - len%128
   273  	}
   274  
   275  	// Length in bits.
   276  	len <<= 3
   277  	padlen := tmp[:t+16]
   278  	// Upper 64 bits are always zero, because len variable has type uint64,
   279  	// and tmp is already zeroed at that index, so we can skip updating it.
   280  	// byteorder.BePutUint64(padlen[t+0:], 0)
   281  	byteorder.BePutUint64(padlen[t+8:], len)
   282  	d.Write(padlen)
   283  
   284  	if d.nx != 0 {
   285  		panic("d.nx != 0")
   286  	}
   287  
   288  	var digest [size512]byte
   289  	byteorder.BePutUint64(digest[0:], d.h[0])
   290  	byteorder.BePutUint64(digest[8:], d.h[1])
   291  	byteorder.BePutUint64(digest[16:], d.h[2])
   292  	byteorder.BePutUint64(digest[24:], d.h[3])
   293  	byteorder.BePutUint64(digest[32:], d.h[4])
   294  	byteorder.BePutUint64(digest[40:], d.h[5])
   295  	if d.size != size384 {
   296  		byteorder.BePutUint64(digest[48:], d.h[6])
   297  		byteorder.BePutUint64(digest[56:], d.h[7])
   298  	}
   299  
   300  	return digest
   301  }
   302
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