def _parse_timestamped_entry(tdf):
with TdfBytesParser(tdf) as parser:
parser.read('timestamp', '!Q') # uint64 -> 8 bytes
entry_type = LogEntryType(
parser.delegate('entry_type', _parse_log_entry_type))
# parse leaf_entry
if entry_type.is_x509_entry:
parser.delegate('signed_entry', _parse_asn1_cert)
parser.res['x509_entry'] = parser.res['signed_entry']
elif entry_type.is_precert_entry:
parser.delegate('signed_entry', _parse_pre_cert)
parser.res['precert_entry'] = parser.res['signed_entry']
else:
raise Exception(flo('Unknown entry_type number: {entry_type}'))
# TODO DEBUG ctlog_get_entries.py related (it looks like some log
# answers are missing
# the ct_extensions,
# or an error in parse routines)
try:
parser.delegate('extensions', _parse_ct_extensions)
except struct.error:
pass
return parser.result()
def _parse_nam_tup(tdf):
with TdfBytesParser(tdf) as parser:
parser.read('lv1', '!s')
parse_lv2 = parser.delegate('_tmp', _parse_lv2)
parser.res.update(parse_lv2)
del parser.res['_tmp']
return parser.result()
def _parse_signature_input(tdf):
with TdfBytesParser(tdf) as parser:
parser.delegate('sct_version', _parse_version)
parser.delegate('signature_type', _parse_signature_type)
# rest of the SignatureInput is identical to an TimestampedEntry
parser.delegate('_tmp', _parse_timestamped_entry)
parser.res.update(parser.res['_tmp'])
del parser.res['_tmp']
return parser.result()
def _parse_merkle_tree_leaf(tdf):
with TdfBytesParser(tdf) as parser:
parser.delegate('version', _parse_version)
leaf_type = parser.delegate('leaf_type', _parse_merkle_leaf_type)
if MerkleLeafType(leaf_type).is_timestamped_entry:
parser.delegate('leaf_entry', _parse_timestamped_entry)
else:
raise Exception('unknown leaf_type: {leaf_type}!')
return parser.result()
def _parse_tbs_certificate(tdf):
with TdfBytesParser(tdf) as parser:
parser.read('len1', '!B')
parser.read('len2', '!B')
parser.read('len3', '!B')
len_der = struct.unpack(
'=I',
struct.pack('!4B', 0, parser.res['len1'], parser.res['len2'],
parser.res['len3']))[0]
from_ = parser.offset
parser.offset += len_der
until = parser.offset
parser.res['der'] = tdf[from_:until]
return parser.result()
def _parse_asn1_cert(tdf):
with TdfBytesParser(tdf) as parser:
parser.read('len1', '!B')
parser.read('len2', '!B')
parser.read('len3', '!B')
der_len = struct.unpack(
'=I',
struct.pack('!4B', 0, parser.res['len1'], parser.res['len2'],
parser.res['len3']))[0]
parser.res['der_len'] = der_len
parser.read('der', flo('!{der_len}s'))
return parser.result()
def _parse_signed_certificate_timestamp(tdf):
with TdfBytesParser(tdf) as parser:
parser.delegate('version', _parse_version)
parser.delegate('id', _parse_log_id)
parser.read('timestamp', '!Q')
parser.delegate('ct_extensions', _parse_ct_extensions)
# digitally-signed struct
parser.read('signature_alg_hash', '!B'),
parser.read('signature_alg_sign', '!B'),
signature_len = parser.read('signature_len', '!H')
parser.read('signature', flo('!{signature_len}s'))
return parser.result()
def _parse_log_entry(tdf):
with TdfBytesParser(tdf) as parser:
entry_type = LogEntryType(
parser.delegate('entry_type', _parse_log_entry_type))
# parse entry
if entry_type.is_x509_entry:
parser.delegate('entry', _parse_x509_chain_entry)
parser.res['x509_entry'] = parser.res['entry']
elif entry_type.is_precert_entry:
parser.delegate('entry', _parse_precert_chain_entry)
parser.res['precert_entry'] = parser.res['entry']
else:
raise Exception(flo('Unknown entry_type: {entry_type}'))
return parser.result()
def _parse_asn1_cert_list(tdf):
with TdfBytesParser(tdf) as parser:
parser.read('len1', '!B')
parser.read('len2', '!B')
parser.read('len3', '!B')
der_list_len = struct.unpack(
'=I',
struct.pack('!4B', 0, parser.res['len1'], parser.res['len2'],
parser.res['len3']))[0]
der_end_offset = parser.offset + der_list_len
list_of_parse_asn1_cert = []
while parser.offset < der_end_offset:
parse_asn1_cert = parser.delegate(_parse_asn1_cert)
list_of_parse_asn1_cert.append(parse_asn1_cert)
parser.res['der_list_len'] = der_list_len
parser.res['list_of_parse_asn1_cert'] = list_of_parse_asn1_cert
return parser.result()
def _parse_merkle_leaf_type(tdf):
with TdfBytesParser(tdf) as parser:
parser.read('val', '!B') # (255)
return parser.result()
def _parse_ct_extensions(tdf):
with TdfBytesParser(tdf) as parser:
parser.read('len', '!H')
parser.res['val'] = None # "Currently, no extensions are specified"
return parser.result()
def _parse_log_id(tdf):
with TdfBytesParser(tdf) as parser:
parser.read('val', '!32s')
return parser.result()
def _parse_log_entry_type(tdf):
with TdfBytesParser(tdf) as parser:
parser.read('val', '!H') # (65535) -> 2 bytes
return parser.result()
def _parse_version(tdf):
with TdfBytesParser(tdf) as parser:
parser.read('val', '!B')
return parser.result()
def _parse_signature_type(tdf):
with TdfBytesParser(tdf) as parser:
parser.read('val', '!B')
return parser.result()
def _parse_precert_chain_entry(tdf):
with TdfBytesParser(tdf) as parser:
parser.delegate('pre_certificate', _parse_asn1_cert),
parser.delegate('precert_chain', _parse_asn1_cert_list),
return parser.result()
def _parse_pre_cert(tdf):
with TdfBytesParser(tdf) as parser:
parser.read('issuer_key_hash', '!32s')
parser.delegate('tbs_certificate', _parse_tbs_certificate)
return parser.result()
def _parse_lv2(tdf):
with TdfBytesParser(tdf) as parser:
parser.read('lv2', '!2s')
return parser.result()
