github.com/noisysockets/noisysockets@v0.21.2-0.20240515114641-7f467e651c90/types/noise_types.go (about)

     1  // SPDX-License-Identifier: MPL-2.0
     2  /*
     3   * Copyright (C) 2024 The Noisy Sockets Authors.
     4   *
     5   * This Source Code Form is subject to the terms of the Mozilla Public
     6   * License, v. 2.0. If a copy of the MPL was not distributed with this
     7   * file, You can obtain one at http://mozilla.org/MPL/2.0/.
     8   *
     9   * Portions of this file are based on code originally from wireguard-go,
    10   *
    11   * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
    12   *
    13   * Permission is hereby granted, free of charge, to any person obtaining a copy of
    14   * this software and associated documentation files (the "Software"), to deal in
    15   * the Software without restriction, including without limitation the rights to
    16   * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
    17   * of the Software, and to permit persons to whom the Software is furnished to do
    18   * so, subject to the following conditions:
    19   *
    20   * The above copyright notice and this permission notice shall be included in all
    21   * copies or substantial portions of the Software.
    22   *
    23   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    24   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    25   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    26   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    27   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    28   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    29   * SOFTWARE.
    30   */
    31  
    32  package types
    33  
    34  import (
    35  	"crypto/rand"
    36  	"crypto/subtle"
    37  	"encoding/base64"
    38  
    39  	"golang.org/x/crypto/curve25519"
    40  )
    41  
    42  const (
    43  	NoisePublicKeySize    = 32
    44  	NoisePrivateKeySize   = 32
    45  	NoisePresharedKeySize = 32
    46  )
    47  
    48  type (
    49  	NoisePublicKey    [NoisePublicKeySize]byte
    50  	NoisePrivateKey   [NoisePrivateKeySize]byte
    51  	NoisePresharedKey [NoisePresharedKeySize]byte
    52  	NoiseNonce        uint64 // padded to 12-bytes
    53  )
    54  
    55  func NewPrivateKey() (sk NoisePrivateKey, err error) {
    56  	_, err = rand.Read(sk[:])
    57  	sk.clamp()
    58  	return
    59  }
    60  
    61  func (sk *NoisePrivateKey) UnmarshalText(text []byte) error {
    62  	b, err := base64.StdEncoding.DecodeString(string(text))
    63  	if err != nil {
    64  		return err
    65  	}
    66  	copy(sk[:], b)
    67  	return nil
    68  }
    69  
    70  func (sk *NoisePrivateKey) clamp() {
    71  	sk[0] &= 248
    72  	sk[31] = (sk[31] & 127) | 64
    73  }
    74  
    75  func (sk NoisePrivateKey) Public() (pk NoisePublicKey) {
    76  	apk := (*[NoisePublicKeySize]byte)(&pk)
    77  	ask := (*[NoisePrivateKeySize]byte)(&sk)
    78  	curve25519.ScalarBaseMult(apk, ask)
    79  	return
    80  }
    81  
    82  func (sk NoisePrivateKey) Equals(tar NoisePrivateKey) bool {
    83  	return subtle.ConstantTimeCompare(sk[:], tar[:]) == 1
    84  }
    85  
    86  func (sk NoisePrivateKey) String() string {
    87  	return base64.StdEncoding.EncodeToString(sk[:])
    88  }
    89  
    90  func (pk *NoisePublicKey) UnmarshalText(text []byte) error {
    91  	b, err := base64.StdEncoding.DecodeString(string(text))
    92  	if err != nil {
    93  		return err
    94  	}
    95  
    96  	copy(pk[:], b)
    97  	return nil
    98  }
    99  
   100  func (pk NoisePublicKey) Equals(tar NoisePublicKey) bool {
   101  	return subtle.ConstantTimeCompare(pk[:], tar[:]) == 1
   102  }
   103  
   104  func (pk NoisePublicKey) String() string {
   105  	return base64.StdEncoding.EncodeToString(pk[:])
   106  }
   107  
   108  func (pk NoisePublicKey) DisplayString() string {
   109  	base64Key := base64.StdEncoding.EncodeToString(pk[:])
   110  	return base64Key[0:4] + "…" + base64Key[39:43]
   111  }