diff options
Diffstat (limited to 'cryptography/hazmat')
| -rw-r--r-- | cryptography/hazmat/bindings/utils.py | 38 |
1 files changed, 30 insertions, 8 deletions
diff --git a/cryptography/hazmat/bindings/utils.py b/cryptography/hazmat/bindings/utils.py index b8253483..318b82bb 100644 --- a/cryptography/hazmat/bindings/utils.py +++ b/cryptography/hazmat/bindings/utils.py @@ -13,6 +13,8 @@ from __future__ import absolute_import, division, print_function +import binascii + import sys import cffi @@ -50,7 +52,8 @@ def build_ffi(module_prefix, modules, pre_include, post_include, libraries): includes.append(module.INCLUDES) customizations.append(module.CUSTOMIZATIONS) - ffi.cdef("\n".join(types + functions + macros)) + cdef_sources = types + functions + macros + ffi.cdef("\n".join(cdef_sources)) # 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 @@ -60,14 +63,16 @@ def build_ffi(module_prefix, modules, pre_include, post_include, libraries): # is legal, but the following will fail to compile: # int foo(int); # int foo(short); + source = "\n".join( + [pre_include] + + includes + + [post_include] + + functions + + customizations + ) lib = ffi.verify( - source="\n".join( - [pre_include] + - includes + - [post_include] + - functions + - customizations - ), + source=source, + modulename=_create_modulename(cdef_sources, source, sys.version), libraries=libraries, ext_package="cryptography", ) @@ -81,3 +86,20 @@ def build_ffi(module_prefix, modules, pre_include, post_include, libraries): delattr(lib, name) return ffi, lib + + +def _create_modulename(cdef_sources, source, sys_version): + """ + cffi creates a modulename internally that incorporates the cffi version. + This will cause cryptography's wheels to break when the version of cffi + the user has does not match what was used when building the wheel. To + resolve this we build our own modulename that uses most of the same code + from cffi but elides the version key. + """ + key = '\x00'.join([sys_version[:3], source] + cdef_sources) + key = key.encode('utf-8') + k1 = hex(binascii.crc32(key[0::2]) & 0xffffffff) + k1 = k1.lstrip('0x').rstrip('L') + k2 = hex(binascii.crc32(key[1::2]) & 0xffffffff) + k2 = k2.lstrip('0').rstrip('L') + return '_Cryptography_cffi_{0}{1}'.format(k1, k2) |