Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/cryptography/hazmat/backends/openssl/backend.py: 43%

1# This file is dual licensed under the terms of the Apache License, Version 

2# 2.0, and the BSD License. See the LICENSE file in the root of this repository 

3# for complete details. 

4 

5from __future__ import annotations 

6 

7from cryptography.hazmat.bindings._rust import openssl as rust_openssl 

8from cryptography.hazmat.bindings.openssl import binding 

9from cryptography.hazmat.primitives import hashes 

10from cryptography.hazmat.primitives._asymmetric import AsymmetricPadding 

11from cryptography.hazmat.primitives.asymmetric import ec 

12from cryptography.hazmat.primitives.asymmetric import utils as asym_utils 

13from cryptography.hazmat.primitives.asymmetric.padding import ( 

14 MGF1, 

15 OAEP, 

16 PSS, 

17 PKCS1v15, 

18) 

19from cryptography.hazmat.primitives.ciphers import ( 

20 CipherAlgorithm, 

21) 

22from cryptography.hazmat.primitives.ciphers.algorithms import ( 

23 AES, 

24) 

25from cryptography.hazmat.primitives.ciphers.modes import ( 

26 CBC, 

27 Mode, 

28) 

29 

30 

31class Backend: 

32 """ 

33 OpenSSL API binding interfaces. 

34 """ 

35 

36 name = "openssl" 

37 

38 # TripleDES encryption is disallowed/deprecated throughout 2023 in 

39 # FIPS 140-3. To keep it simple we denylist any use of TripleDES (TDEA). 

40 _fips_ciphers = (AES,) 

41 # Sometimes SHA1 is still permissible. That logic is contained 

42 # within the various *_supported methods. 

43 _fips_hashes = ( 

44 hashes.SHA224, 

45 hashes.SHA256, 

46 hashes.SHA384, 

47 hashes.SHA512, 

48 hashes.SHA512_224, 

49 hashes.SHA512_256, 

50 hashes.SHA3_224, 

51 hashes.SHA3_256, 

52 hashes.SHA3_384, 

53 hashes.SHA3_512, 

54 hashes.SHAKE128, 

55 hashes.SHAKE256, 

56 ) 

57 _fips_ecdh_curves = ( 

58 ec.SECP224R1, 

59 ec.SECP256R1, 

60 ec.SECP384R1, 

61 ec.SECP521R1, 

62 ) 

63 _fips_rsa_min_key_size = 2048 

64 _fips_rsa_min_public_exponent = 65537 

65 _fips_dsa_min_modulus = 1 << 2048 

66 _fips_dh_min_key_size = 2048 

67 _fips_dh_min_modulus = 1 << _fips_dh_min_key_size 

68 

69 def __init__(self) -> None: 

70 self._binding = binding.Binding() 

71 self._ffi = self._binding.ffi 

72 self._lib = self._binding.lib 

73 self._fips_enabled = rust_openssl.is_fips_enabled() 

74 

75 def __repr__(self) -> str: 

76 return ( 

77 f"<OpenSSLBackend(version: {self.openssl_version_text()}, " 

78 f"FIPS: {self._fips_enabled}, " 

79 f"Legacy: {rust_openssl._legacy_provider_loaded})>" 

80 ) 

81 

82 def openssl_assert(self, ok: bool) -> None: 

83 return binding._openssl_assert(ok) 

84 

85 def _enable_fips(self) -> None: 

86 # This function enables FIPS mode for OpenSSL 3.0.0 on installs that 

87 # have the FIPS provider installed properly. 

88 rust_openssl.enable_fips(rust_openssl._providers) 

89 assert rust_openssl.is_fips_enabled() 

90 self._fips_enabled = rust_openssl.is_fips_enabled() 

91 

92 def openssl_version_text(self) -> str: 

93 """ 

94 Friendly string name of the loaded OpenSSL library. This is not 

95 necessarily the same version as it was compiled against. 

96 

97 Example: OpenSSL 3.2.1 30 Jan 2024 

98 """ 

99 return rust_openssl.openssl_version_text() 

100 

101 def openssl_version_number(self) -> int: 

102 return rust_openssl.openssl_version() 

103 

104 def _evp_md_from_algorithm(self, algorithm: hashes.HashAlgorithm): 

105 if algorithm.name in ("blake2b", "blake2s"): 

106 alg = f"{algorithm.name}{algorithm.digest_size * 8}".encode( 

107 "ascii" 

108 ) 

109 else: 

110 alg = algorithm.name.encode("ascii") 

111 

112 evp_md = self._lib.EVP_get_digestbyname(alg) 

113 return evp_md 

114 

115 def hash_supported(self, algorithm: hashes.HashAlgorithm) -> bool: 

116 if self._fips_enabled and not isinstance(algorithm, self._fips_hashes): 

117 return False 

118 

119 evp_md = self._evp_md_from_algorithm(algorithm) 

120 return evp_md != self._ffi.NULL 

121 

122 def signature_hash_supported( 

123 self, algorithm: hashes.HashAlgorithm 

124 ) -> bool: 

125 # Dedicated check for hashing algorithm use in message digest for 

126 # signatures, e.g. RSA PKCS#1 v1.5 SHA1 (sha1WithRSAEncryption). 

127 if self._fips_enabled and isinstance(algorithm, hashes.SHA1): 

128 return False 

129 return self.hash_supported(algorithm) 

130 

131 def scrypt_supported(self) -> bool: 

132 if self._fips_enabled: 

133 return False 

134 else: 

135 return hasattr(rust_openssl.kdf, "derive_scrypt") 

136 

137 def hmac_supported(self, algorithm: hashes.HashAlgorithm) -> bool: 

138 # FIPS mode still allows SHA1 for HMAC 

139 if self._fips_enabled and isinstance(algorithm, hashes.SHA1): 

140 return True 

141 

142 return self.hash_supported(algorithm) 

143 

144 def cipher_supported(self, cipher: CipherAlgorithm, mode: Mode) -> bool: 

145 if self._fips_enabled: 

146 # FIPS mode requires AES. TripleDES is disallowed/deprecated in 

147 # FIPS 140-3. 

148 if not isinstance(cipher, self._fips_ciphers): 

149 return False 

150 

151 return rust_openssl.ciphers.cipher_supported(cipher, mode) 

152 

153 def pbkdf2_hmac_supported(self, algorithm: hashes.HashAlgorithm) -> bool: 

154 return self.hmac_supported(algorithm) 

155 

156 def _consume_errors(self) -> list[rust_openssl.OpenSSLError]: 

157 return rust_openssl.capture_error_stack() 

158 

159 def _oaep_hash_supported(self, algorithm: hashes.HashAlgorithm) -> bool: 

160 if self._fips_enabled and isinstance(algorithm, hashes.SHA1): 

161 return False 

162 

163 return isinstance( 

164 algorithm, 

165 ( 

166 hashes.SHA1, 

167 hashes.SHA224, 

168 hashes.SHA256, 

169 hashes.SHA384, 

170 hashes.SHA512, 

171 ), 

172 ) 

173 

174 def rsa_padding_supported(self, padding: AsymmetricPadding) -> bool: 

175 if isinstance(padding, PKCS1v15): 

176 return True 

177 elif isinstance(padding, PSS) and isinstance(padding._mgf, MGF1): 

178 # SHA1 is permissible in MGF1 in FIPS even when SHA1 is blocked 

179 # as signature algorithm. 

180 if self._fips_enabled and isinstance( 

181 padding._mgf._algorithm, hashes.SHA1 

182 ): 

183 return True 

184 else: 

185 return self.hash_supported(padding._mgf._algorithm) 

186 elif isinstance(padding, OAEP) and isinstance(padding._mgf, MGF1): 

187 return self._oaep_hash_supported( 

188 padding._mgf._algorithm 

189 ) and self._oaep_hash_supported(padding._algorithm) 

190 else: 

191 return False 

192 

193 def rsa_encryption_supported(self, padding: AsymmetricPadding) -> bool: 

194 if self._fips_enabled and isinstance(padding, PKCS1v15): 

195 return False 

196 else: 

197 return self.rsa_padding_supported(padding) 

198 

199 def dsa_supported(self) -> bool: 

200 return ( 

201 not rust_openssl.CRYPTOGRAPHY_IS_BORINGSSL 

202 and not self._fips_enabled 

203 ) 

204 

205 def dsa_hash_supported(self, algorithm: hashes.HashAlgorithm) -> bool: 

206 if not self.dsa_supported(): 

207 return False 

208 return self.signature_hash_supported(algorithm) 

209 

210 def cmac_algorithm_supported(self, algorithm) -> bool: 

211 return self.cipher_supported( 

212 algorithm, CBC(b"\x00" * algorithm.block_size) 

213 ) 

214 

215 def elliptic_curve_supported(self, curve: ec.EllipticCurve) -> bool: 

216 if self._fips_enabled and not isinstance( 

217 curve, self._fips_ecdh_curves 

218 ): 

219 return False 

220 

221 return rust_openssl.ec.curve_supported(curve) 

222 

223 def elliptic_curve_signature_algorithm_supported( 

224 self, 

225 signature_algorithm: ec.EllipticCurveSignatureAlgorithm, 

226 curve: ec.EllipticCurve, 

227 ) -> bool: 

228 # We only support ECDSA right now. 

229 if not isinstance(signature_algorithm, ec.ECDSA): 

230 return False 

231 

232 return self.elliptic_curve_supported(curve) and ( 

233 isinstance(signature_algorithm.algorithm, asym_utils.Prehashed) 

234 or self.hash_supported(signature_algorithm.algorithm) 

235 ) 

236 

237 def elliptic_curve_exchange_algorithm_supported( 

238 self, algorithm: ec.ECDH, curve: ec.EllipticCurve 

239 ) -> bool: 

240 return self.elliptic_curve_supported(curve) and isinstance( 

241 algorithm, ec.ECDH 

242 ) 

243 

244 def dh_supported(self) -> bool: 

245 return not rust_openssl.CRYPTOGRAPHY_IS_BORINGSSL 

246 

247 def dh_x942_serialization_supported(self) -> bool: 

248 return self._lib.Cryptography_HAS_EVP_PKEY_DHX == 1 

249 

250 def x25519_supported(self) -> bool: 

251 if self._fips_enabled: 

252 return False 

253 return True 

254 

255 def x448_supported(self) -> bool: 

256 if self._fips_enabled: 

257 return False 

258 return ( 

259 not rust_openssl.CRYPTOGRAPHY_IS_LIBRESSL 

260 and not rust_openssl.CRYPTOGRAPHY_IS_BORINGSSL 

261 ) 

262 

263 def ed25519_supported(self) -> bool: 

264 if self._fips_enabled: 

265 return False 

266 return True 

267 

268 def ed448_supported(self) -> bool: 

269 if self._fips_enabled: 

270 return False 

271 return ( 

272 not rust_openssl.CRYPTOGRAPHY_IS_LIBRESSL 

273 and not rust_openssl.CRYPTOGRAPHY_IS_BORINGSSL 

274 ) 

275 

276 def ecdsa_deterministic_supported(self) -> bool: 

277 return ( 

278 rust_openssl.CRYPTOGRAPHY_OPENSSL_320_OR_GREATER 

279 and not self._fips_enabled 

280 ) 

281 

282 def poly1305_supported(self) -> bool: 

283 if self._fips_enabled: 

284 return False 

285 return True 

286 

287 def pkcs7_supported(self) -> bool: 

288 return not rust_openssl.CRYPTOGRAPHY_IS_BORINGSSL 

289 

290 

291backend = Backend()