github.com/googgoog/go-ethereum@v1.9.7/crypto/ecies/params.go (about)

     1  // Copyright (c) 2013 Kyle Isom <kyle@tyrfingr.is>
     2  // Copyright (c) 2012 The Go Authors. All rights reserved.
     3  //
     4  // Redistribution and use in source and binary forms, with or without
     5  // modification, are permitted provided that the following conditions are
     6  // met:
     7  //
     8  //    * Redistributions of source code must retain the above copyright
     9  // notice, this list of conditions and the following disclaimer.
    10  //    * Redistributions in binary form must reproduce the above
    11  // copyright notice, this list of conditions and the following disclaimer
    12  // in the documentation and/or other materials provided with the
    13  // distribution.
    14  //    * Neither the name of Google Inc. nor the names of its
    15  // contributors may be used to endorse or promote products derived from
    16  // this software without specific prior written permission.
    17  //
    18  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    19  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    20  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    21  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    22  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    23  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    24  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    25  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    26  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    27  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    28  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    29  
    30  package ecies
    31  
    32  // This file contains parameters for ECIES encryption, specifying the
    33  // symmetric encryption and HMAC parameters.
    34  
    35  import (
    36  	"crypto"
    37  	"crypto/aes"
    38  	"crypto/cipher"
    39  	"crypto/elliptic"
    40  	"crypto/sha256"
    41  	"crypto/sha512"
    42  	"fmt"
    43  	"hash"
    44  
    45  	ethcrypto "github.com/ethereum/go-ethereum/crypto"
    46  )
    47  
    48  var (
    49  	DefaultCurve                  = ethcrypto.S256()
    50  	ErrUnsupportedECDHAlgorithm   = fmt.Errorf("ecies: unsupported ECDH algorithm")
    51  	ErrUnsupportedECIESParameters = fmt.Errorf("ecies: unsupported ECIES parameters")
    52  )
    53  
    54  type ECIESParams struct {
    55  	Hash      func() hash.Hash // hash function
    56  	hashAlgo  crypto.Hash
    57  	Cipher    func([]byte) (cipher.Block, error) // symmetric cipher
    58  	BlockSize int                                // block size of symmetric cipher
    59  	KeyLen    int                                // length of symmetric key
    60  }
    61  
    62  // Standard ECIES parameters:
    63  // * ECIES using AES128 and HMAC-SHA-256-16
    64  // * ECIES using AES256 and HMAC-SHA-256-32
    65  // * ECIES using AES256 and HMAC-SHA-384-48
    66  // * ECIES using AES256 and HMAC-SHA-512-64
    67  
    68  var (
    69  	ECIES_AES128_SHA256 = &ECIESParams{
    70  		Hash:      sha256.New,
    71  		hashAlgo:  crypto.SHA256,
    72  		Cipher:    aes.NewCipher,
    73  		BlockSize: aes.BlockSize,
    74  		KeyLen:    16,
    75  	}
    76  
    77  	ECIES_AES256_SHA256 = &ECIESParams{
    78  		Hash:      sha256.New,
    79  		hashAlgo:  crypto.SHA256,
    80  		Cipher:    aes.NewCipher,
    81  		BlockSize: aes.BlockSize,
    82  		KeyLen:    32,
    83  	}
    84  
    85  	ECIES_AES256_SHA384 = &ECIESParams{
    86  		Hash:      sha512.New384,
    87  		hashAlgo:  crypto.SHA384,
    88  		Cipher:    aes.NewCipher,
    89  		BlockSize: aes.BlockSize,
    90  		KeyLen:    32,
    91  	}
    92  
    93  	ECIES_AES256_SHA512 = &ECIESParams{
    94  		Hash:      sha512.New,
    95  		hashAlgo:  crypto.SHA512,
    96  		Cipher:    aes.NewCipher,
    97  		BlockSize: aes.BlockSize,
    98  		KeyLen:    32,
    99  	}
   100  )
   101  
   102  var paramsFromCurve = map[elliptic.Curve]*ECIESParams{
   103  	ethcrypto.S256(): ECIES_AES128_SHA256,
   104  	elliptic.P256():  ECIES_AES128_SHA256,
   105  	elliptic.P384():  ECIES_AES256_SHA384,
   106  	elliptic.P521():  ECIES_AES256_SHA512,
   107  }
   108  
   109  func AddParamsForCurve(curve elliptic.Curve, params *ECIESParams) {
   110  	paramsFromCurve[curve] = params
   111  }
   112  
   113  // ParamsFromCurve selects parameters optimal for the selected elliptic curve.
   114  // Only the curves P256, P384, and P512 are supported.
   115  func ParamsFromCurve(curve elliptic.Curve) (params *ECIESParams) {
   116  	return paramsFromCurve[curve]
   117  }