github.com/zmap/zcrypto@v0.0.0-20240512203510-0fef58d9a9db/json/dhe.go (about)

     1  /*
     2   * ZGrab Copyright 2015 Regents of the University of Michigan
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License"); you may not
     5   * use this file except in compliance with the License. You may obtain a copy
     6   * of the License at http://www.apache.org/licenses/LICENSE-2.0
     7   *
     8   * Unless required by applicable law or agreed to in writing, software
     9   * distributed under the License is distributed on an "AS IS" BASIS,
    10   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
    11   * implied. See the License for the specific language governing
    12   * permissions and limitations under the License.
    13   */
    14  
    15  package json
    16  
    17  import (
    18  	"encoding/json"
    19  	"math/big"
    20  )
    21  
    22  // DHParams can be used to store finite-field Diffie-Hellman parameters. At any
    23  // point in time, it is unlikely that both OurPrivate and TheirPrivate will be
    24  // non-nil.
    25  type DHParams struct {
    26  	Prime         *big.Int
    27  	Generator     *big.Int
    28  	ServerPublic  *big.Int
    29  	ServerPrivate *big.Int
    30  	ClientPublic  *big.Int
    31  	ClientPrivate *big.Int
    32  	SessionKey    *big.Int
    33  }
    34  
    35  type auxDHParams struct {
    36  	Prime         *cryptoParameter `json:"prime"`
    37  	Generator     *cryptoParameter `json:"generator"`
    38  	ServerPublic  *cryptoParameter `json:"server_public,omitempty"`
    39  	ServerPrivate *cryptoParameter `json:"server_private,omitempty"`
    40  	ClientPublic  *cryptoParameter `json:"client_public,omitempty"`
    41  	ClientPrivate *cryptoParameter `json:"client_private,omitempty"`
    42  	SessionKey    *cryptoParameter `json:"session_key,omitempty"`
    43  }
    44  
    45  // MarshalJSON implements the json.Marshal interface
    46  func (p *DHParams) MarshalJSON() ([]byte, error) {
    47  	aux := auxDHParams{
    48  		Prime:     &cryptoParameter{Int: p.Prime},
    49  		Generator: &cryptoParameter{Int: p.Generator},
    50  	}
    51  	if p.ServerPublic != nil {
    52  		aux.ServerPublic = &cryptoParameter{Int: p.ServerPublic}
    53  	}
    54  	if p.ServerPrivate != nil {
    55  		aux.ServerPrivate = &cryptoParameter{Int: p.ServerPrivate}
    56  	}
    57  	if p.ClientPublic != nil {
    58  		aux.ClientPublic = &cryptoParameter{Int: p.ClientPublic}
    59  	}
    60  	if p.ClientPrivate != nil {
    61  		aux.ClientPrivate = &cryptoParameter{Int: p.ClientPrivate}
    62  	}
    63  	if p.SessionKey != nil {
    64  		aux.SessionKey = &cryptoParameter{Int: p.SessionKey}
    65  	}
    66  	return json.Marshal(aux)
    67  }
    68  
    69  // UnmarshalJSON implement the json.Unmarshaler interface
    70  func (p *DHParams) UnmarshalJSON(b []byte) error {
    71  	var aux auxDHParams
    72  	if err := json.Unmarshal(b, &aux); err != nil {
    73  		return err
    74  	}
    75  	if aux.Prime != nil {
    76  		p.Prime = aux.Prime.Int
    77  	}
    78  	if aux.Generator != nil {
    79  		p.Generator = aux.Generator.Int
    80  	}
    81  	if aux.ServerPublic != nil {
    82  		p.ServerPublic = aux.ServerPublic.Int
    83  	}
    84  	if aux.ServerPrivate != nil {
    85  		p.ServerPrivate = aux.ServerPrivate.Int
    86  	}
    87  	if aux.ClientPublic != nil {
    88  		p.ClientPublic = aux.ClientPublic.Int
    89  	}
    90  	if aux.ClientPrivate != nil {
    91  		p.ClientPrivate = aux.ClientPrivate.Int
    92  	}
    93  	if aux.SessionKey != nil {
    94  		p.SessionKey = aux.SessionKey.Int
    95  	}
    96  	return nil
    97  }
    98  
    99  // CryptoParameter represents a big.Int used a parameter in some cryptography.
   100  // It serializes to json as a tupe of a base64-encoded number and a length in
   101  // bits.
   102  type cryptoParameter struct {
   103  	*big.Int
   104  }
   105  
   106  type auxCryptoParameter struct {
   107  	Raw    []byte `json:"value"`
   108  	Length int    `json:"length"`
   109  }
   110  
   111  // MarshalJSON implements the json.Marshaler interface
   112  func (p *cryptoParameter) MarshalJSON() ([]byte, error) {
   113  	var aux auxCryptoParameter
   114  	if p.Int != nil {
   115  		aux.Raw = p.Bytes()
   116  		aux.Length = 8 * len(aux.Raw)
   117  	}
   118  	return json.Marshal(&aux)
   119  }
   120  
   121  // UnmarshalJSON implements the json.Unmarshal interface
   122  func (p *cryptoParameter) UnmarshalJSON(b []byte) error {
   123  	var aux auxCryptoParameter
   124  	if err := json.Unmarshal(b, &aux); err != nil {
   125  		return err
   126  	}
   127  	p.Int = new(big.Int)
   128  	p.SetBytes(aux.Raw)
   129  	return nil
   130  }