Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/PyNaCl-1.6.0.dev1-py3.8-linux-x86_64.egg/nacl/bindings/crypto_kx.py: 32%

1# Copyright 2018 Donald Stufft and individual contributors 

2# 

3# Licensed under the Apache License, Version 2.0 (the "License"); 

4# you may not use this file except in compliance with the License. 

5# You may obtain a copy of the License at 

6# 

7# http://www.apache.org/licenses/LICENSE-2.0 

8# 

9# Unless required by applicable law or agreed to in writing, software 

10# distributed under the License is distributed on an "AS IS" BASIS, 

11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 

12# See the License for the specific language governing permissions and 

13# limitations under the License. 

14from typing import Tuple 

15 

16from nacl import exceptions as exc 

17from nacl._sodium import ffi, lib 

18from nacl.exceptions import ensure 

19 

20__all__ = [ 

21 "crypto_kx_keypair", 

22 "crypto_kx_client_session_keys", 

23 "crypto_kx_server_session_keys", 

24 "crypto_kx_PUBLIC_KEY_BYTES", 

25 "crypto_kx_SECRET_KEY_BYTES", 

26 "crypto_kx_SEED_BYTES", 

27 "crypto_kx_SESSION_KEY_BYTES", 

28] 

29 

30""" 

31Implementations of client, server key exchange 

32""" 

33crypto_kx_PUBLIC_KEY_BYTES: int = lib.crypto_kx_publickeybytes() 

34crypto_kx_SECRET_KEY_BYTES: int = lib.crypto_kx_secretkeybytes() 

35crypto_kx_SEED_BYTES: int = lib.crypto_kx_seedbytes() 

36crypto_kx_SESSION_KEY_BYTES: int = lib.crypto_kx_sessionkeybytes() 

37 

38 

39def crypto_kx_keypair() -> Tuple[bytes, bytes]: 

40 """ 

41 Generate a key pair. 

42 This is a duplicate crypto_box_keypair, but 

43 is included for api consistency. 

44 :return: (public_key, secret_key) 

45 :rtype: (bytes, bytes) 

46 """ 

47 public_key = ffi.new("unsigned char[]", crypto_kx_PUBLIC_KEY_BYTES) 

48 secret_key = ffi.new("unsigned char[]", crypto_kx_SECRET_KEY_BYTES) 

49 res = lib.crypto_kx_keypair(public_key, secret_key) 

50 ensure(res == 0, "Key generation failed.", raising=exc.CryptoError) 

51 

52 return ( 

53 ffi.buffer(public_key, crypto_kx_PUBLIC_KEY_BYTES)[:], 

54 ffi.buffer(secret_key, crypto_kx_SECRET_KEY_BYTES)[:], 

55 ) 

56 

57 

58def crypto_kx_seed_keypair(seed: bytes) -> Tuple[bytes, bytes]: 

59 """ 

60 Generate a key pair with a given seed. 

61 This is functionally the same as crypto_box_seed_keypair, however 

62 it uses the blake2b hash primitive instead of sha512. 

63 It is included mainly for api consistency when using crypto_kx. 

64 :param seed: random seed 

65 :type seed: bytes 

66 :return: (public_key, secret_key) 

67 :rtype: (bytes, bytes) 

68 """ 

69 public_key = ffi.new("unsigned char[]", crypto_kx_PUBLIC_KEY_BYTES) 

70 secret_key = ffi.new("unsigned char[]", crypto_kx_SECRET_KEY_BYTES) 

71 ensure( 

72 isinstance(seed, bytes) and len(seed) == crypto_kx_SEED_BYTES, 

73 "Seed must be a {} byte long bytes sequence".format( 

74 crypto_kx_SEED_BYTES 

75 ), 

76 raising=exc.TypeError, 

77 ) 

78 res = lib.crypto_kx_seed_keypair(public_key, secret_key, seed) 

79 ensure(res == 0, "Key generation failed.", raising=exc.CryptoError) 

80 

81 return ( 

82 ffi.buffer(public_key, crypto_kx_PUBLIC_KEY_BYTES)[:], 

83 ffi.buffer(secret_key, crypto_kx_SECRET_KEY_BYTES)[:], 

84 ) 

85 

86 

87def crypto_kx_client_session_keys( 

88 client_public_key: bytes, 

89 client_secret_key: bytes, 

90 server_public_key: bytes, 

91) -> Tuple[bytes, bytes]: 

92 """ 

93 Generate session keys for the client. 

94 :param client_public_key: 

95 :type client_public_key: bytes 

96 :param client_secret_key: 

97 :type client_secret_key: bytes 

98 :param server_public_key: 

99 :type server_public_key: bytes 

100 :return: (rx_key, tx_key) 

101 :rtype: (bytes, bytes) 

102 """ 

103 ensure( 

104 isinstance(client_public_key, bytes) 

105 and len(client_public_key) == crypto_kx_PUBLIC_KEY_BYTES, 

106 "Client public key must be a {} bytes long bytes sequence".format( 

107 crypto_kx_PUBLIC_KEY_BYTES 

108 ), 

109 raising=exc.TypeError, 

110 ) 

111 ensure( 

112 isinstance(client_secret_key, bytes) 

113 and len(client_secret_key) == crypto_kx_SECRET_KEY_BYTES, 

114 "Client secret key must be a {} bytes long bytes sequence".format( 

115 crypto_kx_PUBLIC_KEY_BYTES 

116 ), 

117 raising=exc.TypeError, 

118 ) 

119 ensure( 

120 isinstance(server_public_key, bytes) 

121 and len(server_public_key) == crypto_kx_PUBLIC_KEY_BYTES, 

122 "Server public key must be a {} bytes long bytes sequence".format( 

123 crypto_kx_PUBLIC_KEY_BYTES 

124 ), 

125 raising=exc.TypeError, 

126 ) 

127 

128 rx_key = ffi.new("unsigned char[]", crypto_kx_SESSION_KEY_BYTES) 

129 tx_key = ffi.new("unsigned char[]", crypto_kx_SESSION_KEY_BYTES) 

130 res = lib.crypto_kx_client_session_keys( 

131 rx_key, tx_key, client_public_key, client_secret_key, server_public_key 

132 ) 

133 ensure( 

134 res == 0, 

135 "Client session key generation failed.", 

136 raising=exc.CryptoError, 

137 ) 

138 

139 return ( 

140 ffi.buffer(rx_key, crypto_kx_SESSION_KEY_BYTES)[:], 

141 ffi.buffer(tx_key, crypto_kx_SESSION_KEY_BYTES)[:], 

142 ) 

143 

144 

145def crypto_kx_server_session_keys( 

146 server_public_key: bytes, 

147 server_secret_key: bytes, 

148 client_public_key: bytes, 

149) -> Tuple[bytes, bytes]: 

150 """ 

151 Generate session keys for the server. 

152 :param server_public_key: 

153 :type server_public_key: bytes 

154 :param server_secret_key: 

155 :type server_secret_key: bytes 

156 :param client_public_key: 

157 :type client_public_key: bytes 

158 :return: (rx_key, tx_key) 

159 :rtype: (bytes, bytes) 

160 """ 

161 ensure( 

162 isinstance(server_public_key, bytes) 

163 and len(server_public_key) == crypto_kx_PUBLIC_KEY_BYTES, 

164 "Server public key must be a {} bytes long bytes sequence".format( 

165 crypto_kx_PUBLIC_KEY_BYTES 

166 ), 

167 raising=exc.TypeError, 

168 ) 

169 ensure( 

170 isinstance(server_secret_key, bytes) 

171 and len(server_secret_key) == crypto_kx_SECRET_KEY_BYTES, 

172 "Server secret key must be a {} bytes long bytes sequence".format( 

173 crypto_kx_PUBLIC_KEY_BYTES 

174 ), 

175 raising=exc.TypeError, 

176 ) 

177 ensure( 

178 isinstance(client_public_key, bytes) 

179 and len(client_public_key) == crypto_kx_PUBLIC_KEY_BYTES, 

180 "Client public key must be a {} bytes long bytes sequence".format( 

181 crypto_kx_PUBLIC_KEY_BYTES 

182 ), 

183 raising=exc.TypeError, 

184 ) 

185 

186 rx_key = ffi.new("unsigned char[]", crypto_kx_SESSION_KEY_BYTES) 

187 tx_key = ffi.new("unsigned char[]", crypto_kx_SESSION_KEY_BYTES) 

188 res = lib.crypto_kx_server_session_keys( 

189 rx_key, tx_key, server_public_key, server_secret_key, client_public_key 

190 ) 

191 ensure( 

192 res == 0, 

193 "Server session key generation failed.", 

194 raising=exc.CryptoError, 

195 ) 

196 

197 return ( 

198 ffi.buffer(rx_key, crypto_kx_SESSION_KEY_BYTES)[:], 

199 ffi.buffer(tx_key, crypto_kx_SESSION_KEY_BYTES)[:], 

200 )