2020-10-11 13:46:24 +08:00
|
|
|
use nom::IResult;
|
|
|
|
use nom::bytes::complete::take;
|
2020-10-19 17:05:26 +08:00
|
|
|
use nom::bytes::complete::tag;
|
2020-10-20 15:55:44 +08:00
|
|
|
use nom::bytes::complete::take_till;
|
2020-10-11 13:46:24 +08:00
|
|
|
use nom::combinator::complete;
|
2020-10-20 15:55:44 +08:00
|
|
|
use nom::sequence::preceded;
|
2020-10-11 13:46:24 +08:00
|
|
|
use nom::sequence::tuple;
|
|
|
|
use nom::error::ErrorKind;
|
|
|
|
use smoltcp::Error;
|
|
|
|
use smoltcp::Result;
|
|
|
|
|
|
|
|
use byteorder::{ByteOrder, NetworkEndian, BigEndian};
|
|
|
|
|
|
|
|
use crate::tls_packet::*;
|
|
|
|
use core::convert::TryFrom;
|
|
|
|
|
2020-10-11 23:41:02 +08:00
|
|
|
use alloc::vec::Vec;
|
2020-10-11 13:46:24 +08:00
|
|
|
|
2020-10-11 23:41:02 +08:00
|
|
|
pub(crate) fn parse_tls_repr(bytes: &[u8]) -> IResult<&[u8], TlsRepr> {
|
2020-10-11 13:46:24 +08:00
|
|
|
let content_type = take(1_usize);
|
|
|
|
let version = take(2_usize);
|
|
|
|
let length = take(2_usize);
|
|
|
|
|
|
|
|
let (rest, (content_type, version, length)) =
|
|
|
|
tuple((content_type, version, length))(bytes)?;
|
|
|
|
|
|
|
|
let mut repr = TlsRepr {
|
|
|
|
content_type: TlsContentType::try_from(content_type[0])
|
|
|
|
.unwrap(),
|
|
|
|
|
|
|
|
version: TlsVersion::try_from(NetworkEndian::read_u16(version))
|
|
|
|
.unwrap(),
|
|
|
|
|
|
|
|
length: NetworkEndian::read_u16(length),
|
|
|
|
payload: None,
|
|
|
|
handshake: None,
|
|
|
|
};
|
2020-10-14 17:37:45 +08:00
|
|
|
let (rest, bytes) = take(repr.length)(rest)?;
|
2020-10-11 13:46:24 +08:00
|
|
|
{
|
|
|
|
use crate::tls_packet::TlsContentType::*;
|
|
|
|
match repr.content_type {
|
|
|
|
Handshake => {
|
2020-10-14 17:37:45 +08:00
|
|
|
let (rest, handshake) = complete(
|
|
|
|
parse_handshake
|
|
|
|
)(bytes)?;
|
2020-10-11 13:46:24 +08:00
|
|
|
repr.handshake = Some(handshake);
|
|
|
|
},
|
2020-10-14 17:37:45 +08:00
|
|
|
ChangeCipherSpec | ApplicationData => {
|
2020-10-18 20:02:40 +08:00
|
|
|
let mut vec: Vec<u8> = Vec::new();
|
|
|
|
vec.extend_from_slice(bytes);
|
|
|
|
repr.payload = Some(vec);
|
2020-10-14 17:37:45 +08:00
|
|
|
},
|
|
|
|
_ => todo!()
|
2020-10-11 13:46:24 +08:00
|
|
|
}
|
|
|
|
}
|
2020-10-14 17:37:45 +08:00
|
|
|
Ok((rest, repr))
|
2020-10-11 13:46:24 +08:00
|
|
|
}
|
|
|
|
|
2020-10-20 15:55:44 +08:00
|
|
|
// TODO: Redo EE
|
|
|
|
// Not very appropriate to classify EE as proper handshake
|
|
|
|
// It may include multiple handshakes
|
|
|
|
// Solution 1: Parse handshake again -> Recursion & return type
|
|
|
|
// Solution 2: Force caller to parse in a loop -> Extra parser to handle EE
|
2020-10-19 17:05:26 +08:00
|
|
|
pub(crate) fn parse_handshake(bytes: &[u8]) -> IResult<&[u8], HandshakeRepr> {
|
2020-10-11 13:46:24 +08:00
|
|
|
let handshake_type = take(1_usize);
|
|
|
|
let length = take(3_usize);
|
|
|
|
|
|
|
|
let (rest, (handshake_type, length)) =
|
|
|
|
tuple((handshake_type, length))(bytes)?;
|
|
|
|
|
|
|
|
let mut repr = HandshakeRepr {
|
|
|
|
msg_type: HandshakeType::try_from(handshake_type[0]).unwrap(),
|
|
|
|
length: NetworkEndian::read_u24(length),
|
|
|
|
handshake_data: HandshakeData::Uninitialized,
|
|
|
|
};
|
|
|
|
{
|
|
|
|
use crate::tls_packet::HandshakeType::*;
|
|
|
|
match repr.msg_type {
|
|
|
|
ServerHello => {
|
2020-10-14 17:37:45 +08:00
|
|
|
let (rest, data) = parse_server_hello(rest)?;
|
2020-10-11 23:41:02 +08:00
|
|
|
repr.handshake_data = data;
|
|
|
|
Ok((rest, repr))
|
2020-10-11 13:46:24 +08:00
|
|
|
},
|
2020-10-19 17:05:26 +08:00
|
|
|
EncryptedExtensions => {
|
|
|
|
// Split data into EE and the last TLS content byte
|
|
|
|
let (tls_content_byte, ee_data) = take(repr.length)(rest)?;
|
|
|
|
|
|
|
|
// Process TLS content byte.
|
|
|
|
complete(
|
|
|
|
tag(&[0x16])
|
|
|
|
)(tls_content_byte)?;
|
|
|
|
|
|
|
|
// Process EE
|
|
|
|
let (rest, handshake_data) = parse_encrypted_extensions(
|
|
|
|
ee_data
|
|
|
|
)?;
|
|
|
|
repr.handshake_data = HandshakeData::EncryptedExtensions(
|
|
|
|
handshake_data
|
|
|
|
);
|
|
|
|
|
|
|
|
// Verify that all bytes are comsumed
|
|
|
|
complete(
|
|
|
|
take(0_usize)
|
|
|
|
)(rest)?;
|
|
|
|
|
|
|
|
Ok((&[], repr))
|
|
|
|
}
|
2020-10-11 13:46:24 +08:00
|
|
|
_ => todo!()
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
fn parse_server_hello(bytes: &[u8]) -> IResult<&[u8], HandshakeData> {
|
|
|
|
let version = take(2_usize);
|
|
|
|
let random = take(32_usize);
|
|
|
|
let session_id_echo_length = take(1_usize);
|
|
|
|
|
|
|
|
let (rest, (version, random, session_id_echo_length)) =
|
|
|
|
tuple((version, random, session_id_echo_length))(bytes)?;
|
2020-10-14 17:37:45 +08:00
|
|
|
|
2020-10-11 13:46:24 +08:00
|
|
|
let session_id_echo_length = session_id_echo_length[0];
|
|
|
|
let (rest, session_id_echo) = take(session_id_echo_length)(rest)?;
|
|
|
|
|
|
|
|
let cipher_suite = take(2_usize);
|
|
|
|
let compression_method = take(1_usize);
|
|
|
|
let extension_length = take(2_usize);
|
|
|
|
|
|
|
|
let (mut rest, (cipher_suite, compression_method, extension_length)) =
|
|
|
|
tuple((cipher_suite, compression_method, extension_length))(rest)?;
|
|
|
|
|
|
|
|
let mut server_hello = ServerHello {
|
|
|
|
version: TlsVersion::try_from(NetworkEndian::read_u16(version)).unwrap(),
|
|
|
|
random,
|
2020-10-11 23:41:02 +08:00
|
|
|
session_id_echo_length,
|
2020-10-11 13:46:24 +08:00
|
|
|
session_id_echo,
|
|
|
|
cipher_suite: CipherSuite::try_from(NetworkEndian::read_u16(cipher_suite)).unwrap(),
|
|
|
|
compression_method: compression_method[0],
|
2020-10-11 23:41:02 +08:00
|
|
|
extension_length: NetworkEndian::read_u16(extension_length),
|
|
|
|
extensions: Vec::new(),
|
2020-10-11 13:46:24 +08:00
|
|
|
};
|
|
|
|
|
2020-10-11 23:41:02 +08:00
|
|
|
let mut extension_vec: Vec<Extension> = Vec::new();
|
|
|
|
let mut extension_length: i32 = server_hello.extension_length.into();
|
2020-10-14 17:37:45 +08:00
|
|
|
while extension_length > 0 {
|
|
|
|
let (rem, extension) = parse_extension(rest, HandshakeType::ServerHello)?;
|
2020-10-11 13:46:24 +08:00
|
|
|
rest = rem;
|
2020-10-11 23:41:02 +08:00
|
|
|
extension_length -= i32::try_from(extension.get_length()).unwrap();
|
2020-10-11 13:46:24 +08:00
|
|
|
|
|
|
|
// Todo:: Proper error
|
2020-10-11 23:41:02 +08:00
|
|
|
if extension_length < 0 {
|
2020-10-11 13:46:24 +08:00
|
|
|
todo!()
|
|
|
|
}
|
2020-10-14 17:37:45 +08:00
|
|
|
|
|
|
|
extension_vec.push(extension);
|
2020-10-11 13:46:24 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
server_hello.extensions = extension_vec;
|
|
|
|
Ok((rest, HandshakeData::ServerHello(server_hello)))
|
|
|
|
}
|
|
|
|
|
2020-10-20 15:55:44 +08:00
|
|
|
// For reference: This is the structure of encrypted text
|
|
|
|
// Source: RFC 8446 Section 5.2
|
|
|
|
//
|
|
|
|
// struct {
|
|
|
|
// opaque content[TLSPlaintext.length];
|
|
|
|
// ContentType type;
|
|
|
|
// uint8 zeros[length_of_padding];
|
|
|
|
// } TLSInnerPlaintext;
|
|
|
|
|
2020-10-19 17:05:26 +08:00
|
|
|
fn parse_encrypted_extensions(bytes: &[u8]) -> IResult<&[u8], EncryptedExtensions> {
|
|
|
|
let (mut rest, extension_length) = take(2_usize)(bytes)?;
|
|
|
|
let extension_length: u16 = NetworkEndian::read_u16(extension_length);
|
|
|
|
let mut extension_length_counter: i32 = extension_length.into();
|
|
|
|
let mut extension_vec: Vec<Extension> = Vec::new();
|
|
|
|
|
|
|
|
// Split the data into "extensions" and the rest
|
|
|
|
let (rest, mut encypted_extension_data) =
|
|
|
|
take(usize::try_from(extension_length).unwrap())(rest)?;
|
|
|
|
|
|
|
|
while extension_length_counter > 0 {
|
|
|
|
let (rem, extension) = parse_extension(
|
|
|
|
encypted_extension_data,
|
|
|
|
HandshakeType::EncryptedExtensions
|
|
|
|
)?;
|
|
|
|
encypted_extension_data = rem;
|
|
|
|
extension_length_counter -= i32::try_from(extension.get_length()).unwrap();
|
2020-10-18 20:02:40 +08:00
|
|
|
|
|
|
|
// Todo:: Proper error
|
2020-10-19 17:05:26 +08:00
|
|
|
if extension_length_counter < 0 {
|
2020-10-18 20:02:40 +08:00
|
|
|
todo!()
|
|
|
|
}
|
|
|
|
|
|
|
|
extension_vec.push(extension);
|
2020-10-19 17:05:26 +08:00
|
|
|
}
|
2020-10-18 20:02:40 +08:00
|
|
|
|
|
|
|
let encrypted_extensions = EncryptedExtensions {
|
2020-10-19 17:05:26 +08:00
|
|
|
length: extension_length,
|
2020-10-18 20:02:40 +08:00
|
|
|
extensions: extension_vec
|
2020-10-19 17:05:26 +08:00
|
|
|
};
|
|
|
|
|
|
|
|
// Force completeness. The entire slice is meant to be processed.
|
|
|
|
complete(
|
2020-10-20 15:55:44 +08:00
|
|
|
preceded(
|
|
|
|
take(0_usize),
|
|
|
|
// There may be zeroes beyond the content_type
|
|
|
|
// Take "0" out until no more chaining zeros are found
|
|
|
|
take_till(|byte| byte == 0)
|
|
|
|
)
|
2020-10-19 17:05:26 +08:00
|
|
|
)(rest)?;
|
|
|
|
|
2020-10-18 20:02:40 +08:00
|
|
|
Ok((rest, encrypted_extensions))
|
|
|
|
}
|
|
|
|
|
2020-10-14 17:37:45 +08:00
|
|
|
fn parse_extension(bytes: &[u8], handshake_type: HandshakeType) -> IResult<&[u8], Extension> {
|
2020-10-11 13:46:24 +08:00
|
|
|
let extension_type = take(2_usize);
|
|
|
|
let length = take(2_usize);
|
|
|
|
|
|
|
|
let (rest, (extension_type, length)) =
|
|
|
|
tuple((extension_type, length))(bytes)?;
|
|
|
|
|
2020-10-14 17:37:45 +08:00
|
|
|
let extension_type = ExtensionType::try_from(
|
|
|
|
NetworkEndian::read_u16(extension_type)
|
|
|
|
).unwrap();
|
2020-10-11 13:46:24 +08:00
|
|
|
let length = NetworkEndian::read_u16(length);
|
2020-10-14 17:37:45 +08:00
|
|
|
|
|
|
|
// Process extension data according to extension_type
|
|
|
|
// TODO: Deal with HelloRetryRequest
|
|
|
|
let (rest, extension_data) = {
|
2020-10-18 20:02:40 +08:00
|
|
|
// TODO: Handle all mandatory extension types
|
2020-10-14 17:37:45 +08:00
|
|
|
use ExtensionType::*;
|
|
|
|
match extension_type {
|
|
|
|
SupportedVersions => {
|
|
|
|
match handshake_type {
|
|
|
|
HandshakeType::ClientHello => {
|
|
|
|
todo!()
|
|
|
|
},
|
|
|
|
HandshakeType::ServerHello => {
|
|
|
|
let (rest, selected_version) = take(2_usize)(rest)?;
|
|
|
|
let selected_version = TlsVersion::try_from(
|
|
|
|
NetworkEndian::read_u16(selected_version)
|
|
|
|
).unwrap();
|
|
|
|
(
|
|
|
|
rest,
|
|
|
|
ExtensionData::SupportedVersions(
|
|
|
|
crate::tls_packet::SupportedVersions::ServerHello {
|
|
|
|
selected_version
|
|
|
|
}
|
|
|
|
)
|
|
|
|
)
|
|
|
|
},
|
|
|
|
_ => todo!()
|
|
|
|
}
|
|
|
|
},
|
2020-10-19 17:05:26 +08:00
|
|
|
SupportedGroups => { // NamedGroupList
|
|
|
|
let (rest, length) = take(2_usize)(rest)?;
|
|
|
|
let length = NetworkEndian::read_u16(length);
|
|
|
|
|
|
|
|
// Isolate contents, for easier error handling
|
|
|
|
let (rest, mut rem_data) = take(length)(rest)?;
|
|
|
|
|
|
|
|
let mut named_group_extension = NamedGroupList {
|
|
|
|
length,
|
|
|
|
named_group_list: Vec::new(),
|
|
|
|
};
|
|
|
|
|
|
|
|
for index in 0..(length/2) {
|
|
|
|
let (rem, named_group) = take(2_usize)(rem_data)?;
|
|
|
|
rem_data = rem;
|
|
|
|
let named_group = NamedGroup::try_from(
|
|
|
|
NetworkEndian::read_u16(named_group)
|
|
|
|
).unwrap();
|
|
|
|
named_group_extension.named_group_list.push(named_group);
|
|
|
|
|
|
|
|
// Assure completeness
|
|
|
|
if index == (length/2) {
|
|
|
|
complete(take(0_usize))(rem_data)?;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
(
|
|
|
|
rest,
|
|
|
|
ExtensionData::NegotiatedGroups(
|
|
|
|
named_group_extension
|
|
|
|
)
|
|
|
|
)
|
|
|
|
}
|
2020-10-14 17:37:45 +08:00
|
|
|
KeyShare => {
|
|
|
|
match handshake_type {
|
|
|
|
HandshakeType::ClientHello => {
|
|
|
|
todo!()
|
|
|
|
},
|
|
|
|
HandshakeType::ServerHello => {
|
|
|
|
let group = take(2_usize);
|
|
|
|
let length = take(2_usize);
|
|
|
|
let (rest, (group, length)) =
|
|
|
|
tuple((group, length))(rest)?;
|
|
|
|
let group = NamedGroup::try_from(
|
|
|
|
NetworkEndian::read_u16(group)
|
|
|
|
).unwrap();
|
|
|
|
let length = NetworkEndian::read_u16(length);
|
|
|
|
let (rest, key_exchange_slice) = take(length)(rest)?;
|
|
|
|
let mut key_exchange = Vec::new();
|
|
|
|
key_exchange.extend_from_slice(key_exchange_slice);
|
|
|
|
|
|
|
|
let server_share = KeyShareEntry {
|
|
|
|
group,
|
|
|
|
length,
|
|
|
|
key_exchange,
|
|
|
|
};
|
|
|
|
let key_share_sh = crate::tls_packet::KeyShareEntryContent::KeyShareServerHello {
|
|
|
|
server_share
|
|
|
|
};
|
|
|
|
(rest, ExtensionData::KeyShareEntry(key_share_sh))
|
|
|
|
},
|
|
|
|
_ => todo!()
|
|
|
|
}
|
|
|
|
},
|
|
|
|
_ => todo!()
|
|
|
|
}
|
|
|
|
};
|
2020-10-11 13:46:24 +08:00
|
|
|
|
|
|
|
Ok((
|
|
|
|
rest,
|
|
|
|
Extension {
|
2020-10-14 17:37:45 +08:00
|
|
|
extension_type,
|
2020-10-11 13:46:24 +08:00
|
|
|
length,
|
|
|
|
extension_data
|
|
|
|
}
|
|
|
|
))
|
|
|
|
}
|