def from_stream(body):
"""Parse a Client Hello record from body.
Body should start with the byte representation of an RFC 5246
struct ClientHello
Returns a ClientHello and the number of bytes read from body
Throws a struct.error or IndexError if there is not enough data to parse
properly.
"""
version, index = Version.from_stream(body)
random, read_amt = Random.from_stream(body[index:])
index += read_amt
sessionid_length = struct.unpack_from("B", body, index)[0]
index += 1
session_id, read_amt = (
parse.parse_tls_list(
body[index:], sessionid_length,
parse.parse_opaque))
index += read_amt
cipher_length = struct.unpack_from("!H", body, index)[0]
index += 2
ciphers, read_amt = (
parse.parse_tls_list(
body[index:], cipher_length,
Cipher.from_stream))
index += read_amt
compression_length = struct.unpack_from("B", body, index)[0]
index += 1
compression_methods, read_amt = (
parse.parse_tls_list(
body[index:], compression_length,
CompressionMethod.from_stream))
index += read_amt
extensions = []
# Check if there are extensions present
if index != len(body):
extensions_length = struct.unpack_from("!H", body, index)[0]
index += 2
extensions, read_amt = (
parse.parse_tls_list(
body[index:], extensions_length,
Extension.from_stream))
index += read_amt
return ClientHello(
version, random, session_id, ciphers, compression_methods,
extensions), index
def from_stream(body):
"""Parse a Client Hello record from body.
Body should start with the byte representation of an RFC 5246
struct ClientHello
Returns a ClientHello and the number of bytes read from body
Throws a struct.error or IndexError if there is not enough data to parse
properly.
"""
version, index = Version.from_stream(body)
random, read_amt = Random.from_stream(body[index:])
index += read_amt
sessionid_length = struct.unpack_from("B", body, index)[0]
index += 1
session_id, read_amt = (parse.parse_tls_list(body[index:],
sessionid_length,
parse.parse_opaque))
index += read_amt
cipher_length = struct.unpack_from("!H", body, index)[0]
index += 2
ciphers, read_amt = (parse.parse_tls_list(body[index:], cipher_length,
Cipher.from_stream))
index += read_amt
compression_length = struct.unpack_from("B", body, index)[0]
index += 1
compression_methods, read_amt = (parse.parse_tls_list(
body[index:], compression_length, CompressionMethod.from_stream))
index += read_amt
extensions = []
# Check if there are extensions present
if index != len(body):
extensions_length = struct.unpack_from("!H", body, index)[0]
index += 2
extensions, read_amt = (parse.parse_tls_list(
body[index:], extensions_length, Extension.from_stream))
index += read_amt
return ClientHello(version, random, session_id, ciphers,
compression_methods, extensions), index
def from_stream(body):
"""Parse a SSLv2 Client Hello record from body.
Body should start with the byte representation struct ClientHello
starting at the version field.
See http://tools.ietf.org/html/rfc5246#appendix-E.2
Returns a ClientHello and the number of bytes read from body
Throws a struct.error or IndexError if there is not enough data to parse
properly.
"""
version, index = Version.from_stream(body)
ciphers_length, sessionid_length, random_length = struct.unpack_from(
"!HHH", body, index)
index += 6;
if ciphers_length % 3 != 0:
raise ValueError("Cipher spec list length not a multiple of 3")
if ciphers_length + sessionid_length + random_length \
!= len(body) - index:
raise ValueError("Not enough data or too much data")
if random_length < 16 or random_length > 32:
raise ValueError("Random challenge too short or too long")
ciphers, read_amt = (
parse.parse_tls_list(
body[index:], ciphers_length,
Cipher.from_stream))
index += read_amt
session_id, read_amt = (
parse.parse_tls_list(
body[index:], sessionid_length,
parse.parse_opaque))
index += read_amt
random = body[index:index + random_length]
index += random_length
return ClientHello(
version, random, session_id, ciphers), index
def from_stream(body):
"""Parse a SSLv2 Client Hello record from body.
Body should start with the byte representation struct ClientHello
starting at the version field.
See http://tools.ietf.org/html/rfc5246#appendix-E.2
Returns a ClientHello and the number of bytes read from body
Throws a struct.error or IndexError if there is not enough data to parse
properly.
"""
version, index = Version.from_stream(body)
ciphers_length, sessionid_length, random_length = struct.unpack_from(
"!HHH", body, index)
index += 6
if ciphers_length % 3 != 0:
raise ValueError("Cipher spec list length not a multiple of 3")
if ciphers_length + sessionid_length + random_length \
!= len(body) - index:
raise ValueError("Not enough data or too much data")
if random_length < 16 or random_length > 32:
raise ValueError("Random challenge too short or too long")
ciphers, read_amt = (parse.parse_tls_list(body[index:], ciphers_length,
Cipher.from_stream))
index += read_amt
session_id, read_amt = (parse.parse_tls_list(body[index:],
sessionid_length,
parse.parse_opaque))
index += read_amt
random = body[index:index + random_length]
index += random_length
return ClientHello(version, random, session_id, ciphers), index
