hashes.go

     1  // Copyright 2014 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 sha3
     6  
     7  // This file provides functions for creating instances of the SHA-3
     8  // and SHAKE hash functions, as well as utility functions for hashing
     9  // bytes.
    10  
    11  import (
    12  	"hash"
    13  )
    14  
    15  // New224 creates a new SHA3-224 hash.
    16  // Its generic security strength is 224 bits against preimage attacks,
    17  // and 112 bits against collision attacks.
    18  func New224() hash.Hash {
    19  	return new224()
    20  }
    21  
    22  // New256 creates a new SHA3-256 hash.
    23  // Its generic security strength is 256 bits against preimage attacks,
    24  // and 128 bits against collision attacks.
    25  func New256() hash.Hash {
    26  	return new256()
    27  }
    28  
    29  // New384 creates a new SHA3-384 hash.
    30  // Its generic security strength is 384 bits against preimage attacks,
    31  // and 192 bits against collision attacks.
    32  func New384() hash.Hash {
    33  	return new384()
    34  }
    35  
    36  // New512 creates a new SHA3-512 hash.
    37  // Its generic security strength is 512 bits against preimage attacks,
    38  // and 256 bits against collision attacks.
    39  func New512() hash.Hash {
    40  	return new512()
    41  }
    42  
    43  func new224Generic() *state {
    44  	return &state{rate: 144, outputLen: 28, dsbyte: 0x06}
    45  }
    46  
    47  func new256Generic() *state {
    48  	return &state{rate: 136, outputLen: 32, dsbyte: 0x06}
    49  }
    50  
    51  func new384Generic() *state {
    52  	return &state{rate: 104, outputLen: 48, dsbyte: 0x06}
    53  }
    54  
    55  func new512Generic() *state {
    56  	return &state{rate: 72, outputLen: 64, dsbyte: 0x06}
    57  }
    58  
    59  // NewLegacyKeccak256 creates a new Keccak-256 hash.
    60  //
    61  // Only use this function if you require compatibility with an existing cryptosystem
    62  // that uses non-standard padding. All other users should use New256 instead.
    63  func NewLegacyKeccak256() hash.Hash { return &state{rate: 136, outputLen: 32, dsbyte: 0x01} }
    64  
    65  // NewLegacyKeccak512 creates a new Keccak-512 hash.
    66  //
    67  // Only use this function if you require compatibility with an existing cryptosystem
    68  // that uses non-standard padding. All other users should use New512 instead.
    69  func NewLegacyKeccak512() hash.Hash { return &state{rate: 72, outputLen: 64, dsbyte: 0x01} }
    70  
    71  // Sum224 returns the SHA3-224 digest of the data.
    72  func Sum224(data []byte) (digest [28]byte) {
    73  	h := New224()
    74  	h.Write(data)
    75  	h.Sum(digest[:0])
    76  	return
    77  }
    78  
    79  // Sum256 returns the SHA3-256 digest of the data.
    80  func Sum256(data []byte) (digest [32]byte) {
    81  	h := New256()
    82  	h.Write(data)
    83  	h.Sum(digest[:0])
    84  	return
    85  }
    86  
    87  // Sum384 returns the SHA3-384 digest of the data.
    88  func Sum384(data []byte) (digest [48]byte) {
    89  	h := New384()
    90  	h.Write(data)
    91  	h.Sum(digest[:0])
    92  	return
    93  }
    94  
    95  // Sum512 returns the SHA3-512 digest of the data.
    96  func Sum512(data []byte) (digest [64]byte) {
    97  	h := New512()
    98  	h.Write(data)
    99  	h.Sum(digest[:0])
   100  	return
   101  }
   102
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