blob: 990925006ad9592939f31eaf989ee9113cb37e2e [file] [log] [blame]
Jean-Paul Calderone6462b072015-03-29 07:03:11 -04001from warnings import warn
Jean-Paul Calderonecbb68cc2015-04-11 12:41:30 -04002import sys
Jean-Paul Calderone6462b072015-03-29 07:03:11 -04003
Jean-Paul Calderone4f0467a2014-01-11 11:58:41 -05004from six import PY3, binary_type, text_type
5
Jean-Paul Calderonee36b31a2014-01-08 16:55:06 -05006from cryptography.hazmat.bindings.openssl.binding import Binding
7binding = Binding()
8ffi = binding.ffi
9lib = binding.lib
Jean-Paul Calderonec86bb7d2013-12-29 10:25:59 -050010
Stephen Holsapple0d9815f2014-08-27 19:36:53 -070011
12
13def text(charp):
Jean-Paul Calderone130cd0e2015-03-15 15:49:33 -040014 """
15 Get a native string type representing of the given CFFI ``char*`` object.
16
17 :param charp: A C-style string represented using CFFI.
18
19 :return: :class:`str`
20 """
Jean-Paul Calderone6d862182015-04-11 07:24:52 -040021 if not charp:
22 return ""
Stephen Holsapple0d9815f2014-08-27 19:36:53 -070023 return native(ffi.string(charp))
24
25
26
27def exception_from_error_queue(exception_type):
28 """
29 Convert an OpenSSL library failure into a Python exception.
30
31 When a call to the native OpenSSL library fails, this is usually signalled
32 by the return value, and an error code is stored in an error queue
33 associated with the current thread. The err library provides functions to
34 obtain these error codes and textual error messages.
35 """
Jean-Paul Calderonede075462014-01-18 10:34:12 -050036
Jean-Paul Calderonec86bb7d2013-12-29 10:25:59 -050037 errors = []
Stephen Holsapple0d9815f2014-08-27 19:36:53 -070038
Jean-Paul Calderonec86bb7d2013-12-29 10:25:59 -050039 while True:
40 error = lib.ERR_get_error()
41 if error == 0:
42 break
43 errors.append((
Jean-Paul Calderonede075462014-01-18 10:34:12 -050044 text(lib.ERR_lib_error_string(error)),
45 text(lib.ERR_func_error_string(error)),
46 text(lib.ERR_reason_error_string(error))))
Jean-Paul Calderonec86bb7d2013-12-29 10:25:59 -050047
Stephen Holsapple0d9815f2014-08-27 19:36:53 -070048 raise exception_type(errors)
Jean-Paul Calderone4f0467a2014-01-11 11:58:41 -050049
50
51
52def native(s):
53 """
54 Convert :py:class:`bytes` or :py:class:`unicode` to the native
Jean-Paul Calderoneaca50f42014-01-11 14:43:37 -050055 :py:class:`str` type, using UTF-8 encoding if conversion is necessary.
Jean-Paul Calderone4f0467a2014-01-11 11:58:41 -050056
57 :raise UnicodeError: The input string is not UTF-8 decodeable.
58
59 :raise TypeError: The input is neither :py:class:`bytes` nor
60 :py:class:`unicode`.
61 """
62 if not isinstance(s, (binary_type, text_type)):
63 raise TypeError("%r is neither bytes nor unicode" % s)
64 if PY3:
65 if isinstance(s, binary_type):
66 return s.decode("utf-8")
67 else:
68 if isinstance(s, text_type):
69 return s.encode("utf-8")
70 return s
71
72
73
Jean-Paul Calderonecbb68cc2015-04-11 12:41:30 -040074def path_string(s):
75 """
76 Convert a Python string to a :py:class:`bytes` string identifying the same
77 path and which can be passed into an OpenSSL API accepting a filename.
78
79 :param s: An instance of :py:class:`bytes` or :py:class:`unicode`.
80
81 :return: An instance of :py:class:`bytes`.
82 """
83 if isinstance(s, binary_type):
84 return s
85 elif isinstance(s, text_type):
86 return s.encode(sys.getfilesystemencoding())
87 else:
88 raise TypeError("Path must be represented as bytes or unicode string")
89
90
Jean-Paul Calderone4f0467a2014-01-11 11:58:41 -050091if PY3:
92 def byte_string(s):
93 return s.encode("charmap")
94else:
95 def byte_string(s):
96 return s
Jean-Paul Calderone6462b072015-03-29 07:03:11 -040097
Jean-Paul Calderone0c021992015-03-29 07:46:30 -040098_TEXT_WARNING = (
Jean-Paul Calderone13a0e652015-03-29 07:58:51 -040099 text_type.__name__ + " for {0} is no longer accepted, use bytes"
Jean-Paul Calderone6462b072015-03-29 07:03:11 -0400100)
101
102def warn_text(label, obj):
Jean-Paul Calderone0894b172015-03-29 07:15:14 -0400103 """
104 If ``obj`` is text, emit a warning that it should be bytes instead and try
105 to convert it to bytes automatically.
106
107 :param str label: The name of the parameter from which ``obj`` was taken
108 (so a developer can easily find the source of the problem and correct
109 it).
110
111 :return: If ``obj`` is the text string type, a ``bytes`` object giving the
112 UTF-8 encoding of that text is returned. Otherwise, ``obj`` itself is
113 returned.
114 """
Jean-Paul Calderone6462b072015-03-29 07:03:11 -0400115 if isinstance(obj, text_type):
116 warn(
117 _TEXT_WARNING.format(label),
118 category=DeprecationWarning,
119 stacklevel=3
120 )
121 return obj.encode('utf-8')
122 return obj