2 Interface to OpenSSL BIO library
4 from ctypescrypto import libcrypto
5 from ctypes import c_char_p, c_void_p, c_int, string_at, c_long
6 from ctypes import POINTER, byref, create_string_buffer
9 Provides interface to OpenSSL memory bios
10 use str() or unicode() to get contents of writable bio
11 use bio member to pass to libcrypto function
13 def __init__(self, data=None):
15 If data is specified, creates read-only BIO. If data is
16 None, creates writable BIO, contents of which can be retrieved
20 method = libcrypto.BIO_s_mem()
21 self.bio = libcrypto.BIO_new(method)
23 self.bio = libcrypto.BIO_new_mem_buf(c_char_p(data), len(data))
27 Cleans up memory used by bio
29 libcrypto.BIO_free(self.bio)
34 Returns current contents of buffer as byte string
36 string_ptr = c_char_p(None)
37 string_len = libcrypto.BIO_ctrl(self.bio, 3, 0, byref(string_ptr))
38 return string_at(string_ptr, string_len)
40 def __unicode__(self):
42 Attempts to interpret current contents of buffer as UTF-8 string
43 and convert it to unicode
45 return str(self).decode("utf-8")
47 def read(self, length=None):
49 Reads data from readble BIO. For test purposes.
50 @param length - if specifed, limits amount of data read.
51 If not BIO is read until end of buffer
53 if not length is None:
54 if not isinstance(length, (int, long)):
55 raise TypeError("length to read should be number")
56 buf = create_string_buffer(length)
57 readbytes = libcrypto.BIO_read(self.bio, buf, length)
59 raise NotImplementedError("Function is not supported by" +
65 return buf.raw[:readbytes]
67 buf = create_string_buffer(1024)
71 readbytes = libcrypto.BIO_read(self.bio, buf, 1024)
73 raise NotImplementedError("Function is not supported by " +
78 out += buf.raw[:readbytes]
81 def write(self, data):
83 Writes data to writable bio. For test purposes
85 if isinstance(data, unicode):
86 data = data.encode("utf-8")
90 written = libcrypto.BIO_write(self.bio, data, len(data))
92 raise NotImplementedError("Function not supported by this BIO")
93 if written < len(data):
94 raise IOError("Not all data were successfully written")
98 Resets the read-only bio to start and discards all data from
101 libcrypto.BIO_ctrl(self.bio, 1, 0, None)
104 libcrypto.BIO_s_mem.restype = c_void_p
105 libcrypto.BIO_new.restype = c_void_p
106 libcrypto.BIO_new.argtypes = (c_void_p, )
107 libcrypto.BIO_ctrl.restype = c_long
108 libcrypto.BIO_ctrl.argtypes = (c_void_p, c_int, c_long, POINTER(c_char_p))
109 libcrypto.BIO_read.argtypes = (c_void_p, c_char_p, c_int)
110 libcrypto.BIO_write.argtypes = (c_void_p, c_char_p, c_int)
111 libcrypto.BIO_free.argtypes = (c_void_p, )
112 libcrypto.BIO_new_mem_buf.restype = c_void_p
113 libcrypto.BIO_new_mem_buf.argtypes = (c_char_p, c_int)