github.com/arieschain/arieschain@v0.0.0-20191023063405-37c074544356/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  // Redistribution and use in source and binary forms, with or without
     4  // modification, are permitted provided that the following conditions are
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    15  // this software without specific prior written permission.
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    17  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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    27  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    28  
    29  package ecies
    30  
    31  // This file contains parameters for ECIES encryption, specifying the
    32  // symmetric encryption and HMAC parameters.
    33  
    34  import (
    35  	"crypto"
    36  	"crypto/aes"
    37  	"crypto/cipher"
    38  	"crypto/elliptic"
    39  	"crypto/sha256"
    40  	"crypto/sha512"
    41  	"fmt"
    42  	"hash"
    43  
    44  	ethcrypto "github.com/quickchainproject/quickchain/crypto"
    45  )
    46  
    47  var (
    48  	DefaultCurve                  = ethcrypto.S256()
    49  	ErrUnsupportedECDHAlgorithm   = fmt.Errorf("ecies: unsupported ECDH algorithm")
    50  	ErrUnsupportedECIESParameters = fmt.Errorf("ecies: unsupported ECIES parameters")
    51  )
    52  
    53  type ECIESParams struct {
    54  	Hash      func() hash.Hash // hash function
    55  	hashAlgo  crypto.Hash
    56  	Cipher    func([]byte) (cipher.Block, error) // symmetric cipher
    57  	BlockSize int                                // block size of symmetric cipher
    58  	KeyLen    int                                // length of symmetric key
    59  }
    60  
    61  // Standard ECIES parameters:
    62  // * ECIES using AES128 and HMAC-SHA-256-16
    63  // * ECIES using AES256 and HMAC-SHA-256-32
    64  // * ECIES using AES256 and HMAC-SHA-384-48
    65  // * ECIES using AES256 and HMAC-SHA-512-64
    66  
    67  var (
    68  	ECIES_AES128_SHA256 = &ECIESParams{
    69  		Hash:      sha256.New,
    70  		hashAlgo:  crypto.SHA256,
    71  		Cipher:    aes.NewCipher,
    72  		BlockSize: aes.BlockSize,
    73  		KeyLen:    16,
    74  	}
    75  
    76  	ECIES_AES256_SHA256 = &ECIESParams{
    77  		Hash:      sha256.New,
    78  		hashAlgo:  crypto.SHA256,
    79  		Cipher:    aes.NewCipher,
    80  		BlockSize: aes.BlockSize,
    81  		KeyLen:    32,
    82  	}
    83  
    84  	ECIES_AES256_SHA384 = &ECIESParams{
    85  		Hash:      sha512.New384,
    86  		hashAlgo:  crypto.SHA384,
    87  		Cipher:    aes.NewCipher,
    88  		BlockSize: aes.BlockSize,
    89  		KeyLen:    32,
    90  	}
    91  
    92  	ECIES_AES256_SHA512 = &ECIESParams{
    93  		Hash:      sha512.New,
    94  		hashAlgo:  crypto.SHA512,
    95  		Cipher:    aes.NewCipher,
    96  		BlockSize: aes.BlockSize,
    97  		KeyLen:    32,
    98  	}
    99  )
   100  
   101  var paramsFromCurve = map[elliptic.Curve]*ECIESParams{
   102  	ethcrypto.S256(): ECIES_AES128_SHA256,
   103  	elliptic.P256():  ECIES_AES128_SHA256,
   104  	elliptic.P384():  ECIES_AES256_SHA384,
   105  	elliptic.P521():  ECIES_AES256_SHA512,
   106  }
   107  
   108  func AddParamsForCurve(curve elliptic.Curve, params *ECIESParams) {
   109  	paramsFromCurve[curve] = params
   110  }
   111  
   112  // ParamsFromCurve selects parameters optimal for the selected elliptic curve.
   113  // Only the curves P256, P384, and P512 are supported.
   114  func ParamsFromCurve(curve elliptic.Curve) (params *ECIESParams) {
   115  	return paramsFromCurve[curve]
   116  }