diff options
Diffstat (limited to 'cryptography/hazmat/bindings/openssl/backend.py')
| -rw-r--r-- | cryptography/hazmat/bindings/openssl/backend.py | 71 |
1 files changed, 47 insertions, 24 deletions
diff --git a/cryptography/hazmat/bindings/openssl/backend.py b/cryptography/hazmat/bindings/openssl/backend.py index fc73dd39..0c3d22d5 100644 --- a/cryptography/hazmat/bindings/openssl/backend.py +++ b/cryptography/hazmat/bindings/openssl/backend.py @@ -18,11 +18,14 @@ import sys import cffi +from cryptography.exceptions import UnsupportedAlgorithm from cryptography.hazmat.primitives import interfaces -from cryptography.hazmat.primitives.block.ciphers import ( +from cryptography.hazmat.primitives.ciphers.algorithms import ( AES, Blowfish, Camellia, CAST5, TripleDES, ) -from cryptography.hazmat.primitives.block.modes import CBC, CTR, ECB, OFB, CFB +from cryptography.hazmat.primitives.ciphers.modes import ( + CBC, CTR, ECB, OFB, CFB +) class Backend(object): @@ -54,29 +57,45 @@ class Backend(object): "x509v3", ] + ffi = None + lib = None + def __init__(self): - self.ffi = cffi.FFI() + self._ensure_ffi_initialized() + + self.ciphers = Ciphers(self) + self.hashes = Hashes(self) + self.hmacs = HMACs(self) + + @classmethod + def _ensure_ffi_initialized(cls): + if cls.ffi is not None and cls.lib is not None: + return + + ffi = cffi.FFI() includes = [] functions = [] macros = [] - for name in self._modules: + customizations = [] + for name in cls._modules: module_name = "cryptography.hazmat.bindings.openssl." + name __import__(module_name) module = sys.modules[module_name] - self.ffi.cdef(module.TYPES) + ffi.cdef(module.TYPES) macros.append(module.MACROS) functions.append(module.FUNCTIONS) includes.append(module.INCLUDES) + customizations.append(module.CUSTOMIZATIONS) # loop over the functions & macros after declaring all the types # so we can set interdependent types in different files and still # have them all defined before we parse the funcs & macros for func in functions: - self.ffi.cdef(func) + ffi.cdef(func) for macro in macros: - self.ffi.cdef(macro) + ffi.cdef(macro) # We include functions here so that if we got any of their definitions # wrong, the underlying C compiler will explode. In C you are allowed @@ -86,17 +105,15 @@ class Backend(object): # is legal, but the following will fail to compile: # int foo(int); # int foo(short); - self.lib = self.ffi.verify( - source="\n".join(includes + functions), + lib = ffi.verify( + source="\n".join(includes + functions + customizations), libraries=["crypto", "ssl"], ) - self.lib.OpenSSL_add_all_algorithms() - self.lib.SSL_load_error_strings() - - self.ciphers = Ciphers(self) - self.hashes = Hashes(self) - self.hmacs = HMACs(self) + cls.ffi = ffi + cls.lib = lib + cls.lib.OpenSSL_add_all_algorithms() + cls.lib.SSL_load_error_strings() def openssl_version_text(self): """ @@ -128,10 +145,15 @@ class _CipherContext(object): ctx = self._backend.ffi.gc(ctx, self._backend.lib.EVP_CIPHER_CTX_free) registry = self._backend.ciphers._cipher_registry - evp_cipher = registry[type(cipher), type(mode)]( - self._backend, cipher, mode - ) - assert evp_cipher != self._backend.ffi.NULL + try: + adapter = registry[type(cipher), type(mode)] + except KeyError: + raise UnsupportedAlgorithm + + evp_cipher = adapter(self._backend, cipher, mode) + if evp_cipher == self._backend.ffi.NULL: + raise UnsupportedAlgorithm + if isinstance(mode, interfaces.ModeWithInitializationVector): iv_nonce = mode.initialization_vector elif isinstance(mode, interfaces.ModeWithNonce): @@ -297,19 +319,20 @@ class HMACs(object): evp_md = self._backend.lib.EVP_get_digestbyname( hash_cls.name.encode('ascii')) assert evp_md != self._backend.ffi.NULL - res = self._backend.lib.HMAC_Init_ex(ctx, key, len(key), evp_md, - self._backend.ffi.NULL) + res = self._backend.lib.Cryptography_HMAC_Init_ex( + ctx, key, len(key), evp_md, self._backend.ffi.NULL + ) assert res != 0 return ctx def update_ctx(self, ctx, data): - res = self._backend.lib.HMAC_Update(ctx, data, len(data)) + res = self._backend.lib.Cryptography_HMAC_Update(ctx, data, len(data)) assert res != 0 def finalize_ctx(self, ctx, digest_size): buf = self._backend.ffi.new("unsigned char[]", digest_size) buflen = self._backend.ffi.new("unsigned int *", digest_size) - res = self._backend.lib.HMAC_Final(ctx, buf, buflen) + res = self._backend.lib.Cryptography_HMAC_Final(ctx, buf, buflen) assert res != 0 self._backend.lib.HMAC_CTX_cleanup(ctx) return self._backend.ffi.buffer(buf)[:digest_size] @@ -319,7 +342,7 @@ class HMACs(object): self._backend.lib.HMAC_CTX_init(copied_ctx) copied_ctx = self._backend.ffi.gc(copied_ctx, self._backend.lib.HMAC_CTX_cleanup) - res = self._backend.lib.HMAC_CTX_copy(copied_ctx, ctx) + res = self._backend.lib.Cryptography_HMAC_CTX_copy(copied_ctx, ctx) assert res != 0 return copied_ctx |