def mpi2str(l, limit):
"""Convert a list of MPIs to a byte-string.
:Parameters:
- `l`: list of MPI integers
- `limit`: dummy parameter to follow svt_*() suit
:Returns: MPI byte-string
:note: This should probably return some sort of an index like `str2mpi()`
since a limit < len(l) might be useful. But it's not useful now.
"""
d = []
for i in l:
i_d = int2str(i)
i_length = len(i_d)
bit_count = sigbits(i_d[0]) + (8 * (i_length - 1))
i_length_str = int2str(bit_count)
if 2 < len(i_length_str):
raise ValueError, "MPI integer > two octs: %s octets used>" % str(
i_length)
elif 1 == len(i_length_str):
i_length_str = ''.join(['\x00', i_length_str])
d.append(''.join([i_length_str,
i_d])) # since limit checks complete mpi
if limit == len(d):
break
return ''.join(d)
def create_MPI(i):
"""Create an MPI out of an integer.
:Parameters:
- `i`: integer
:Returns: `MPI` instance
"""
d = []
i_d = STN.int2str(i)
i_length = len(i_d)
bit_count = STN.sigbits(i_d[0]) + (8 * (i_length - 1))
i_length_str = STN.int2str(bit_count)
if 2 < len(i_length_str):
raise ValueError, "int is larger than two octets can specify - int occupies %s octets" % str(
i_length)
elif 1 == len(i_length_str):
i_length_str = ''.join(['\x00', i_length_str])
d.append(i_length_str)
d.append(i_d)
return MPI(''.join(d))
def create_MPI(i):
"""Create an MPI out of an integer.
:Parameters:
- `i`: integer
:Returns: `MPI` instance
"""
d = []
i_d = STN.int2str(i)
i_length = len(i_d)
bit_count = STN.sigbits(i_d[0]) + (8 * (i_length - 1))
i_length_str = STN.int2str(bit_count)
if 2 < len(i_length_str):
raise ValueError, "int is larger than two octets can specify - int occupies %s octets" % str(i_length)
elif 1 == len(i_length_str):
i_length_str = ''.join(['\x00', i_length_str])
d.append(i_length_str)
d.append(i_d)
return MPI(''.join(d))
