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/fips140"
    11  	"crypto/internal/fips140deps/byteorder"
    12  	"errors"
    13  	"hash"
    14  )
    15  
    16  const (
    17  	// size512 is the size, in bytes, of a SHA-512 checksum.
    18  	size512 = 64
    19  
    20  	// size224 is the size, in bytes, of a SHA-512/224 checksum.
    21  	size224 = 28
    22  
    23  	// size256 is the size, in bytes, of a SHA-512/256 checksum.
    24  	size256 = 32
    25  
    26  	// size384 is the size, in bytes, of a SHA-384 checksum.
    27  	size384 = 48
    28  
    29  	// blockSize is the block size, in bytes, of the SHA-512/224,
    30  	// SHA-512/256, SHA-384 and SHA-512 hash functions.
    31  	blockSize = 128
    32  )
    33  
    34  // The maximum number of bytes that can be passed to block(). The limit exists
    35  // because implementations that rely on assembly routines are not preemptible.
    36  const maxAsmIters = 512
    37  const maxAsmSize = chunk * maxAsmIters // 64KiB
    38  
    39  const (
    40  	chunk     = 128
    41  	init0     = 0x6a09e667f3bcc908
    42  	init1     = 0xbb67ae8584caa73b
    43  	init2     = 0x3c6ef372fe94f82b
    44  	init3     = 0xa54ff53a5f1d36f1
    45  	init4     = 0x510e527fade682d1
    46  	init5     = 0x9b05688c2b3e6c1f
    47  	init6     = 0x1f83d9abfb41bd6b
    48  	init7     = 0x5be0cd19137e2179
    49  	init0_224 = 0x8c3d37c819544da2
    50  	init1_224 = 0x73e1996689dcd4d6
    51  	init2_224 = 0x1dfab7ae32ff9c82
    52  	init3_224 = 0x679dd514582f9fcf
    53  	init4_224 = 0x0f6d2b697bd44da8
    54  	init5_224 = 0x77e36f7304c48942
    55  	init6_224 = 0x3f9d85a86a1d36c8
    56  	init7_224 = 0x1112e6ad91d692a1
    57  	init0_256 = 0x22312194fc2bf72c
    58  	init1_256 = 0x9f555fa3c84c64c2
    59  	init2_256 = 0x2393b86b6f53b151
    60  	init3_256 = 0x963877195940eabd
    61  	init4_256 = 0x96283ee2a88effe3
    62  	init5_256 = 0xbe5e1e2553863992
    63  	init6_256 = 0x2b0199fc2c85b8aa
    64  	init7_256 = 0x0eb72ddc81c52ca2
    65  	init0_384 = 0xcbbb9d5dc1059ed8
    66  	init1_384 = 0x629a292a367cd507
    67  	init2_384 = 0x9159015a3070dd17
    68  	init3_384 = 0x152fecd8f70e5939
    69  	init4_384 = 0x67332667ffc00b31
    70  	init5_384 = 0x8eb44a8768581511
    71  	init6_384 = 0xdb0c2e0d64f98fa7
    72  	init7_384 = 0x47b5481dbefa4fa4
    73  )
    74  
    75  // Digest is a SHA-384, SHA-512, SHA-512/224, or SHA-512/256 [hash.Hash]
    76  // implementation.
    77  type Digest struct {
    78  	h    [8]uint64
    79  	x    [chunk]byte
    80  	nx   int
    81  	len  uint64
    82  	size int // size224, size256, size384, or size512
    83  }
    84  
    85  func (d *Digest) Reset() {
    86  	switch d.size {
    87  	case size384:
    88  		d.h[0] = init0_384
    89  		d.h[1] = init1_384
    90  		d.h[2] = init2_384
    91  		d.h[3] = init3_384
    92  		d.h[4] = init4_384
    93  		d.h[5] = init5_384
    94  		d.h[6] = init6_384
    95  		d.h[7] = init7_384
    96  	case size224:
    97  		d.h[0] = init0_224
    98  		d.h[1] = init1_224
    99  		d.h[2] = init2_224
   100  		d.h[3] = init3_224
   101  		d.h[4] = init4_224
   102  		d.h[5] = init5_224
   103  		d.h[6] = init6_224
   104  		d.h[7] = init7_224
   105  	case size256:
   106  		d.h[0] = init0_256
   107  		d.h[1] = init1_256
   108  		d.h[2] = init2_256
   109  		d.h[3] = init3_256
   110  		d.h[4] = init4_256
   111  		d.h[5] = init5_256
   112  		d.h[6] = init6_256
   113  		d.h[7] = init7_256
   114  	case size512:
   115  		d.h[0] = init0
   116  		d.h[1] = init1
   117  		d.h[2] = init2
   118  		d.h[3] = init3
   119  		d.h[4] = init4
   120  		d.h[5] = init5
   121  		d.h[6] = init6
   122  		d.h[7] = init7
   123  	default:
   124  		panic("unknown size")
   125  	}
   126  	d.nx = 0
   127  	d.len = 0
   128  }
   129  
   130  const (
   131  	magic384      = "sha\x04"
   132  	magic512_224  = "sha\x05"
   133  	magic512_256  = "sha\x06"
   134  	magic512      = "sha\x07"
   135  	marshaledSize = len(magic512) + 8*8 + chunk + 8
   136  )
   137  
   138  func (d *Digest) MarshalBinary() ([]byte, error) {
   139  	return d.AppendBinary(make([]byte, 0, marshaledSize))
   140  }
   141  
   142  func (d *Digest) AppendBinary(b []byte) ([]byte, error) {
   143  	switch d.size {
   144  	case size384:
   145  		b = append(b, magic384...)
   146  	case size224:
   147  		b = append(b, magic512_224...)
   148  	case size256:
   149  		b = append(b, magic512_256...)
   150  	case size512:
   151  		b = append(b, magic512...)
   152  	default:
   153  		panic("unknown size")
   154  	}
   155  	b = byteorder.BEAppendUint64(b, d.h[0])
   156  	b = byteorder.BEAppendUint64(b, d.h[1])
   157  	b = byteorder.BEAppendUint64(b, d.h[2])
   158  	b = byteorder.BEAppendUint64(b, d.h[3])
   159  	b = byteorder.BEAppendUint64(b, d.h[4])
   160  	b = byteorder.BEAppendUint64(b, d.h[5])
   161  	b = byteorder.BEAppendUint64(b, d.h[6])
   162  	b = byteorder.BEAppendUint64(b, d.h[7])
   163  	b = append(b, d.x[:d.nx]...)
   164  	b = append(b, make([]byte, len(d.x)-d.nx)...)
   165  	b = byteorder.BEAppendUint64(b, d.len)
   166  	return b, nil
   167  }
   168  
   169  func (d *Digest) UnmarshalBinary(b []byte) error {
   170  	if len(b) < len(magic512) {
   171  		return errors.New("crypto/sha512: invalid hash state identifier")
   172  	}
   173  	switch {
   174  	case d.size == size384 && string(b[:len(magic384)]) == magic384:
   175  	case d.size == size224 && string(b[:len(magic512_224)]) == magic512_224:
   176  	case d.size == size256 && string(b[:len(magic512_256)]) == magic512_256:
   177  	case d.size == size512 && string(b[:len(magic512)]) == magic512:
   178  	default:
   179  		return errors.New("crypto/sha512: invalid hash state identifier")
   180  	}
   181  	if len(b) != marshaledSize {
   182  		return errors.New("crypto/sha512: invalid hash state size")
   183  	}
   184  	b = b[len(magic512):]
   185  	b, d.h[0] = consumeUint64(b)
   186  	b, d.h[1] = consumeUint64(b)
   187  	b, d.h[2] = consumeUint64(b)
   188  	b, d.h[3] = consumeUint64(b)
   189  	b, d.h[4] = consumeUint64(b)
   190  	b, d.h[5] = consumeUint64(b)
   191  	b, d.h[6] = consumeUint64(b)
   192  	b, d.h[7] = consumeUint64(b)
   193  	b = b[copy(d.x[:], b):]
   194  	b, d.len = consumeUint64(b)
   195  	d.nx = int(d.len % chunk)
   196  	return nil
   197  }
   198  
   199  func consumeUint64(b []byte) ([]byte, uint64) {
   200  	return b[8:], byteorder.BEUint64(b)
   201  }
   202  
   203  func (d *Digest) Clone() (hash.Cloner, error) {
   204  	r := *d
   205  	return &r, nil
   206  }
   207  
   208  // New returns a new Digest computing the SHA-512 hash.
   209  func New() *Digest {
   210  	d := &Digest{size: size512}
   211  	d.Reset()
   212  	return d
   213  }
   214  
   215  // New512_224 returns a new Digest computing the SHA-512/224 hash.
   216  func New512_224() *Digest {
   217  	d := &Digest{size: size224}
   218  	d.Reset()
   219  	return d
   220  }
   221  
   222  // New512_256 returns a new Digest computing the SHA-512/256 hash.
   223  func New512_256() *Digest {
   224  	d := &Digest{size: size256}
   225  	d.Reset()
   226  	return d
   227  }
   228  
   229  // New384 returns a new Digest computing the SHA-384 hash.
   230  func New384() *Digest {
   231  	d := &Digest{size: size384}
   232  	d.Reset()
   233  	return d
   234  }
   235  
   236  func (d *Digest) Size() int {
   237  	return d.size
   238  }
   239  
   240  func (d *Digest) BlockSize() int { return blockSize }
   241  
   242  func (d *Digest) Write(p []byte) (nn int, err error) {
   243  	nn = len(p)
   244  	d.len += uint64(nn)
   245  	if d.nx > 0 {
   246  		n := copy(d.x[d.nx:], p)
   247  		d.nx += n
   248  		if d.nx == chunk {
   249  			block(d, d.x[:])
   250  			d.nx = 0
   251  		}
   252  		p = p[n:]
   253  	}
   254  	if len(p) >= chunk {
   255  		n := len(p) &^ (chunk - 1)
   256  		for n > maxAsmSize {
   257  			block(d, p[:maxAsmSize])
   258  			p = p[maxAsmSize:]
   259  			n -= maxAsmSize
   260  		}
   261  		block(d, p[:n])
   262  		p = p[n:]
   263  	}
   264  	if len(p) > 0 {
   265  		d.nx = copy(d.x[:], p)
   266  	}
   267  	return
   268  }
   269  
   270  func (d *Digest) Sum(in []byte) []byte {
   271  	fips140.RecordApproved()
   272  	// Make a copy of d so that caller can keep writing and summing.
   273  	d0 := new(Digest)
   274  	*d0 = *d
   275  	hash := d0.checkSum()
   276  	return append(in, hash[:d.size]...)
   277  }
   278  
   279  func (d *Digest) checkSum() [size512]byte {
   280  	// Padding. Add a 1 bit and 0 bits until 112 bytes mod 128.
   281  	len := d.len
   282  	var tmp [128 + 16]byte // padding + length buffer
   283  	tmp[0] = 0x80
   284  	var t uint64
   285  	if len%128 < 112 {
   286  		t = 112 - len%128
   287  	} else {
   288  		t = 128 + 112 - len%128
   289  	}
   290  
   291  	// Length in bits.
   292  	len <<= 3
   293  	padlen := tmp[:t+16]
   294  	// Upper 64 bits are always zero, because len variable has type uint64,
   295  	// and tmp is already zeroed at that index, so we can skip updating it.
   296  	// byteorder.BEPutUint64(padlen[t+0:], 0)
   297  	byteorder.BEPutUint64(padlen[t+8:], len)
   298  	d.Write(padlen)
   299  
   300  	if d.nx != 0 {
   301  		panic("d.nx != 0")
   302  	}
   303  
   304  	var digest [size512]byte
   305  	byteorder.BEPutUint64(digest[0:], d.h[0])
   306  	byteorder.BEPutUint64(digest[8:], d.h[1])
   307  	byteorder.BEPutUint64(digest[16:], d.h[2])
   308  	byteorder.BEPutUint64(digest[24:], d.h[3])
   309  	byteorder.BEPutUint64(digest[32:], d.h[4])
   310  	byteorder.BEPutUint64(digest[40:], d.h[5])
   311  	if d.size != size384 {
   312  		byteorder.BEPutUint64(digest[48:], d.h[6])
   313  		byteorder.BEPutUint64(digest[56:], d.h[7])
   314  	}
   315  
   316  	return digest
   317  }
   318
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