2 from allmydata.util import idlib
4 # the URI shall be an ascii representation of the file. It shall contain
5 # enough information to retrieve and validate the contents. It shall be
6 # expressed in a limited character set (namely [TODO]).
8 def pack_uri(codec_name, codec_params, tail_codec_params,
9 verifierid, fileid, key,
10 roothash, needed_shares, total_shares, size, segment_size):
11 # applications should pass keyword parameters into this
12 assert isinstance(codec_name, str)
13 assert len(codec_name) < 10
14 assert ":" not in codec_name
15 assert isinstance(codec_params, str)
16 assert ":" not in codec_params
17 assert isinstance(tail_codec_params, str)
18 assert ":" not in tail_codec_params
19 assert isinstance(verifierid, str)
20 assert len(verifierid) == 20 # sha1 hash
21 assert isinstance(fileid, str)
22 assert len(fileid) == 20 # sha1 hash
23 assert isinstance(key, str)
24 assert len(key) == 16 # AES-128
25 return "URI:%s:%s:%s:%s:%s:%s:%s:%s:%s:%s:%s" % (codec_name, codec_params, tail_codec_params, idlib.b2a(verifierid), idlib.b2a(fileid), idlib.b2a(key), idlib.b2a(roothash), needed_shares, total_shares, size, segment_size)
29 assert uri.startswith("URI:")
31 header, d['codec_name'], d['codec_params'], d['tail_codec_params'], verifierid_s, fileid_s, key_s, roothash_s, needed_shares_s, total_shares_s, size_s, segment_size_s = uri.split(":")
32 assert header == "URI"
33 d['verifierid'] = idlib.a2b(verifierid_s)
34 d['fileid'] = idlib.a2b(fileid_s)
35 d['key'] = idlib.a2b(key_s)
36 d['roothash'] = idlib.a2b(roothash_s)
37 d['needed_shares'] = int(needed_shares_s)
38 d['total_shares'] = int(total_shares_s)
39 d['size'] = int(size_s)
40 d['segment_size'] = int(segment_size_s)