Remove old code, fix bug with MAX_LENGTH_VALUE

This commit is contained in:
Paul Hauner 2019-05-06 11:51:50 +10:00
parent 9d27f67643
commit c31ef5cf7f
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GPG Key ID: D362883A9218FCC6
3 changed files with 34 additions and 595 deletions

View File

@ -173,209 +173,3 @@ fn decode_offset(bytes: &[u8]) -> Result<usize, DecodeError> {
Ok(u32::from_le_bytes(array) as usize)
}
}
/*
/// Decode the given bytes for the given type
///
/// The single ssz encoded value/container/list will be decoded as the given type,
/// by recursively calling `ssz_decode`.
/// Check on totality for underflowing the length of bytes and overflow checks done per container
pub fn decode<T>(ssz_bytes: &[u8]) -> Result<(T), DecodeError>
where
T: Decodable,
{
let (decoded, i): (T, usize) = match T::ssz_decode(ssz_bytes, 0) {
Err(e) => return Err(e),
Ok(v) => v,
};
if i < ssz_bytes.len() {
return Err(DecodeError::TooLong);
}
Ok(decoded)
}
/// Decode a vector (list) of encoded bytes.
///
/// Each element in the list will be decoded and placed into the vector.
pub fn decode_ssz_list<T>(ssz_bytes: &[u8], index: usize) -> Result<(Vec<T>, usize), DecodeError>
where
T: Decodable,
{
if index + LENGTH_BYTES > ssz_bytes.len() {
return Err(DecodeError::TooShort);
};
// get the length
let serialized_length = match decode_length(ssz_bytes, index, LENGTH_BYTES) {
Err(v) => return Err(v),
Ok(v) => v,
};
let final_len: usize = index + LENGTH_BYTES + serialized_length;
if final_len > ssz_bytes.len() {
return Err(DecodeError::TooShort);
};
let mut tmp_index = index + LENGTH_BYTES;
let mut res_vec: Vec<T> = Vec::new();
while tmp_index < final_len {
match T::ssz_decode(ssz_bytes, tmp_index) {
Err(v) => return Err(v),
Ok(v) => {
tmp_index = v.1;
res_vec.push(v.0);
}
};
}
Ok((res_vec, final_len))
}
/// Given some number of bytes, interpret the first four
/// bytes as a 32-bit little-endian integer and return the
/// result.
pub fn decode_length(
bytes: &[u8],
index: usize,
length_bytes: usize,
) -> Result<usize, DecodeError> {
if bytes.len() < index + length_bytes {
return Err(DecodeError::TooShort);
};
let mut len: usize = 0;
for (i, byte) in bytes
.iter()
.enumerate()
.take(index + length_bytes)
.skip(index)
{
let offset = (i - index) * 8;
len |= (*byte as usize) << offset;
}
Ok(len)
}
#[cfg(test)]
mod tests {
use super::super::encode::*;
use super::*;
#[test]
fn test_ssz_decode_length() {
let decoded = decode_length(&vec![1, 0, 0, 0], 0, LENGTH_BYTES);
assert_eq!(decoded.unwrap(), 1);
let decoded = decode_length(&vec![0, 1, 0, 0], 0, LENGTH_BYTES);
assert_eq!(decoded.unwrap(), 256);
let decoded = decode_length(&vec![255, 1, 0, 0], 0, LENGTH_BYTES);
assert_eq!(decoded.unwrap(), 511);
let decoded = decode_length(&vec![255, 255, 255, 255], 0, LENGTH_BYTES);
assert_eq!(decoded.unwrap(), 4294967295);
}
#[test]
fn test_encode_decode_length() {
let params: Vec<usize> = vec![
0,
1,
2,
3,
7,
8,
16,
2 ^ 8,
2 ^ 8 + 1,
2 ^ 16,
2 ^ 16 + 1,
2 ^ 24,
2 ^ 24 + 1,
2 ^ 32,
];
for i in params {
let decoded = decode_length(&encode_length(i, LENGTH_BYTES), 0, LENGTH_BYTES).unwrap();
assert_eq!(i, decoded);
}
}
#[test]
fn test_encode_decode_ssz_list() {
let test_vec: Vec<u16> = vec![256; 12];
let mut stream = SszStream::new();
stream.append_vec(&test_vec);
let ssz = stream.drain();
// u16
let decoded: (Vec<u16>, usize) = decode_ssz_list(&ssz, 0).unwrap();
assert_eq!(decoded.0, test_vec);
assert_eq!(decoded.1, LENGTH_BYTES + (12 * 2));
}
#[test]
fn test_decode_ssz_list() {
// u16
let v: Vec<u16> = vec![10, 10, 10, 10];
let decoded: (Vec<u16>, usize) =
decode_ssz_list(&vec![8, 0, 0, 0, 10, 0, 10, 0, 10, 0, 10, 0], 0).unwrap();
assert_eq!(decoded.0, v);
assert_eq!(decoded.1, LENGTH_BYTES + (4 * 2));
// u32
let v: Vec<u32> = vec![10, 10, 10, 10];
let decoded: (Vec<u32>, usize) = decode_ssz_list(
&vec![
16, 0, 0, 0, 10, 0, 0, 0, 10, 0, 0, 0, 10, 0, 0, 0, 10, 0, 0, 00,
],
0,
)
.unwrap();
assert_eq!(decoded.0, v);
assert_eq!(decoded.1, 20);
// u64
let v: Vec<u64> = vec![10, 10, 10, 10];
let decoded: (Vec<u64>, usize) = decode_ssz_list(
&vec![
32, 0, 0, 0, 10, 0, 0, 0, 0, 0, 0, 0, 10, 0, 0, 0, 0, 0, 0, 0, 10, 0, 0, 0, 0, 0,
0, 0, 10, 0, 0, 0, 0, 0, 0, 0,
],
0,
)
.unwrap();
assert_eq!(decoded.0, v);
assert_eq!(decoded.1, LENGTH_BYTES + (8 * 4));
// Check that it can accept index
let v: Vec<usize> = vec![15, 15, 15, 15];
let offset = 10;
let decoded: (Vec<usize>, usize) = decode_ssz_list(
&vec![
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 32, 0, 0, 0, 15, 0, 0, 0, 0, 0, 0, 0, 15, 0, 0, 0, 0,
0, 0, 0, 15, 0, 0, 0, 0, 0, 0, 0, 15, 0, 0, 0, 0, 0, 0, 0,
],
offset,
)
.unwrap();
assert_eq!(decoded.0, v);
assert_eq!(decoded.1, offset + LENGTH_BYTES + (8 * 4));
// Check that length > bytes throws error
let decoded: Result<(Vec<usize>, usize), DecodeError> =
decode_ssz_list(&vec![32, 0, 0, 0, 15, 0, 0, 0, 0, 0, 0, 0], 0);
assert_eq!(decoded, Err(DecodeError::TooShort));
// Check that incorrect index throws error
let decoded: Result<(Vec<usize>, usize), DecodeError> =
decode_ssz_list(&vec![15, 0, 0, 0, 0, 0, 0, 0], 16);
assert_eq!(decoded, Err(DecodeError::TooShort));
}
}
*/

View File

@ -64,197 +64,62 @@ impl<'a> SszEncoder<'a> {
}
}
/*
pub struct VariableLengths {
pub fixed_bytes_position: usize,
pub variable_bytes_length: usize,
}
/// Provides a buffer for appending SSZ values.
#[derive(Default)]
pub struct SszStream {
fixed_bytes: Vec<u8>,
variable_bytes: Vec<u8>,
variable_lengths: Vec<VariableLengths>,
}
impl SszStream {
/// Create a new, empty stream for writing SSZ values.
pub fn new() -> Self {
SszStream {
fixed_bytes: vec![],
variable_bytes: vec![],
variable_lengths: vec![],
}
}
/*
/// Append some item to the stream.
pub fn append<T: Encodable>(&mut self, item: &T) {
let mut bytes = item.as_ssz_bytes();
if T::is_ssz_fixed_len() {
self.app
self.fixed_bytes.append(&mut bytes);
} else {
self.variable_lengths.push(VariableLengths {
fixed_bytes_position: self.fixed_bytes.len(),
variable_bytes_length: bytes.len(),
});
self.fixed_bytes
.append(&mut vec![0; BYTES_PER_LENGTH_OFFSET]);
self.variable_bytes.append(&mut bytes);
}
}
*/
pub fn reserve<T: Encodable>(&mut self, additional: usize) {
if T::is_ssz_fixed_len() {
self.fixed_bytes.reserve(additional * T::ssz_fixed_len());
} else {
self.fixed_bytes
.reserve(additional * BYTES_PER_LENGTH_OFFSET);
self.variable_lengths.reserve(additional);
}
}
pub fn append_fixed_bytes(&mut self, bytes: &[u8]) {
self.fixed_bytes.extend_from_slice(bytes)
}
pub fn append_variable_bytes(&mut self, bytes: &[u8]) {
self.variable_lengths.push(VariableLengths {
fixed_bytes_position: self.fixed_bytes.len(),
variable_bytes_length: bytes.len(),
});
self.fixed_bytes
.append(&mut vec![0; BYTES_PER_LENGTH_OFFSET]);
self.variable_bytes.extend_from_slice(bytes);
}
/// Update the offsets (if any) in the fixed-length bytes to correctly point to the values in
/// the variable length part.
pub fn apply_offsets(&mut self) {
let mut running_offset = self.fixed_bytes.len();
for v in &self.variable_lengths {
let offset = running_offset;
running_offset += v.variable_bytes_length;
self.fixed_bytes.splice(
v.fixed_bytes_position..v.fixed_bytes_position + BYTES_PER_LENGTH_OFFSET,
encode_length(offset),
);
}
}
/// Append the variable-length bytes to the fixed-length bytes and return the result.
pub fn drain(mut self) -> Vec<u8> {
self.apply_offsets();
self.fixed_bytes.append(&mut self.variable_bytes);
self.fixed_bytes
}
}
*/
/// Encode `len` as a little-endian byte vec of `BYTES_PER_LENGTH_OFFSET` length.
///
/// If `len` is larger than `2 ^ BYTES_PER_LENGTH_OFFSET`, a `debug_assert` is raised.
pub fn encode_length(len: usize) -> Vec<u8> {
// Note: it is possible for `len` to be larger than what can be encoded in
// `BYTES_PER_LENGTH_OFFSET` bytes, triggering this debug assertion.
//
// These are the alternatives to using a `debug_assert` here:
//
// 1. Use `assert`.
// 2. Push an error to the caller (e.g., `Option` or `Result`).
// 3. Ignore it completely.
//
// I have avoided (1) because it's basically a choice between "produce invalid SSZ" or "kill
// the entire program". I figure it may be possible for an attacker to trigger this assert and
// take the program down -- I think producing invalid SSZ is a better option than this.
//
// I have avoided (2) because this error will need to be propagated upstream, making encoding a
// function which may fail. I don't think this is ergonomic and the upsides don't outweigh the
// downsides.
//
// I figure a `debug_assertion` is better than (3) as it will give us a change to detect the
// error during testing.
//
// If you have a different opinion, feel free to start an issue and tag @paulhauner.
debug_assert!(len <= MAX_LENGTH_VALUE);
len.to_le_bytes()[0..BYTES_PER_LENGTH_OFFSET].to_vec()
}
/*
#[cfg(test)]
mod tests {
use super::*;
#[test]
#[should_panic]
fn test_encode_length_0_bytes_panic() {
encode_length(0, 0);
}
fn test_encode_length() {
assert_eq!(encode_length(0), vec![0; 4]);
assert_eq!(encode_length(1), vec![1, 0, 0, 0]);
#[test]
fn test_encode_length_4_bytes() {
assert_eq!(encode_length(0, LENGTH_BYTES), vec![0; 4]);
assert_eq!(encode_length(1, LENGTH_BYTES), vec![1, 0, 0, 0]);
assert_eq!(encode_length(255, LENGTH_BYTES), vec![255, 0, 0, 0]);
assert_eq!(encode_length(256, LENGTH_BYTES), vec![0, 1, 0, 0]);
assert_eq!(
encode_length(4294967295, LENGTH_BYTES), // 2^(3*8) - 1
vec![255, 255, 255, 255]
encode_length(MAX_LENGTH_VALUE),
vec![255; BYTES_PER_LENGTH_OFFSET]
);
}
#[test]
fn test_encode_lower_length() {
assert_eq!(encode_length(0, LENGTH_BYTES - 2), vec![0; 2]);
assert_eq!(encode_length(1, LENGTH_BYTES - 2), vec![1, 0]);
}
#[test]
fn test_encode_higher_length() {
assert_eq!(encode_length(0, LENGTH_BYTES + 2), vec![0; 6]);
assert_eq!(encode_length(1, LENGTH_BYTES + 2), vec![1, 0, 0, 0, 0, 0]);
}
#[test]
#[should_panic]
fn test_encode_length_4_bytes_panic() {
encode_length(4294967296, LENGTH_BYTES); // 2^(3*8)
#[cfg(debug_assertions)]
fn test_encode_length_above_max_debug_panics() {
encode_length(MAX_LENGTH_VALUE + 1);
}
#[test]
fn test_encode_list() {
let test_vec: Vec<u16> = vec![256; 12];
let mut stream = SszStream::new();
stream.append_vec(&test_vec);
let ssz = stream.drain();
assert_eq!(ssz.len(), LENGTH_BYTES + (12 * 2));
assert_eq!(ssz[0..4], *vec![24, 0, 0, 0]);
assert_eq!(ssz[4..6], *vec![0, 1]);
}
#[test]
fn test_encode_mixed_prefixed() {
let test_vec: Vec<u16> = vec![100, 200];
let test_value: u8 = 5;
let mut stream = SszStream::new();
stream.append_vec(&test_vec);
stream.append(&test_value);
let ssz = stream.drain();
assert_eq!(ssz.len(), LENGTH_BYTES + (2 * 2) + 1);
assert_eq!(ssz[0..4], *vec![4, 0, 0, 0]);
assert_eq!(ssz[4..6], *vec![100, 0]);
assert_eq!(ssz[6..8], *vec![200, 0]);
assert_eq!(ssz[8], 5);
}
#[test]
fn test_encode_mixed_postfixed() {
let test_value: u8 = 5;
let test_vec: Vec<u16> = vec![100, 200];
let mut stream = SszStream::new();
stream.append(&test_value);
stream.append_vec(&test_vec);
let ssz = stream.drain();
assert_eq!(ssz.len(), 1 + LENGTH_BYTES + (2 * 2));
assert_eq!(ssz[0], 5);
assert_eq!(ssz[1..5], *vec![4, 0, 0, 0]);
assert_eq!(ssz[5..7], *vec![100, 0]);
assert_eq!(ssz[7..9], *vec![200, 0]);
#[cfg(not(debug_assertions))]
fn test_encode_length_above_max_not_debug_does_not_panic() {
assert_eq!(encode_length(MAX_LENGTH_VALUE + 1), vec![0; 4]);
}
}
*/

View File

@ -1,18 +1,3 @@
/*
* This is a WIP of implementing an alternative
* serialization strategy. It attempts to follow Vitalik's
* "simpleserialize" format here:
* https://github.com/ethereum/beacon_chain/blob/master/beacon_chain/utils/simpleserialize.py
*
* This implementation is not final and would almost certainly
* have issues.
*/
/*
extern crate bytes;
extern crate ethereum_types;
pub mod decode;
*/
mod decode;
mod encode;
@ -20,7 +5,7 @@ pub use decode::{Decodable, DecodeError, SszDecoderBuilder};
pub use encode::{Encodable, SszEncoder};
pub const BYTES_PER_LENGTH_OFFSET: usize = 4;
pub const MAX_LENGTH_VALUE: usize = 1 << (BYTES_PER_LENGTH_OFFSET * 8) - 1;
pub const MAX_LENGTH_VALUE: usize = (1 << (BYTES_PER_LENGTH_OFFSET * 8)) - 1;
/// Convenience function to SSZ encode an object supporting ssz::Encode.
///
@ -31,208 +16,3 @@ where
{
val.as_ssz_bytes()
}
/*
mod impl_decode;
mod impl_encode;
pub use crate::decode::{decode, decode_ssz_list, Decodable, DecodeError};
pub use crate::encode::{Encodable, SszStream};
pub use hashing::hash;
pub const LENGTH_BYTES: usize = 4;
pub const MAX_LIST_SIZE: usize = 1 << (4 * 8);
#[cfg(test)]
mod tests {
extern crate hex;
extern crate yaml_rust;
use self::yaml_rust::yaml;
use super::*;
use std::{fs::File, io::prelude::*, path::PathBuf};
#[test]
pub fn test_vector_uint_bounds() {
let mut file = {
let mut file_path_buf = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
file_path_buf.push("src/test_vectors/uint_bounds.yaml");
File::open(file_path_buf).unwrap()
};
let mut yaml_str = String::new();
file.read_to_string(&mut yaml_str).unwrap();
let docs = yaml::YamlLoader::load_from_str(&yaml_str).unwrap();
let doc = &docs[0];
// Load test cases
let test_cases = doc["test_cases"].clone();
for test_case in test_cases {
// Only the valid cases are checked as parse::<uX>() will fail for all invalid cases
if test_case["valid"].as_bool().unwrap() {
// Convert test vector 'ssz' encoded yaml to Vec<u8>
let ssz = test_case["ssz"].as_str().unwrap().trim_start_matches("0x");
let test_vector_bytes = hex::decode(ssz).unwrap();
// Convert test vector 'value' to ssz encoded bytes
let mut bytes: Vec<u8>;
match test_case["type"].as_str().unwrap() {
"uint8" => {
let value: u8 = test_case["value"].as_str().unwrap().parse::<u8>().unwrap();
bytes = ssz_encode::<u8>(&value); // check encoding
// Check decoding
let decoded = decode::<u8>(&test_vector_bytes).unwrap();
assert_eq!(decoded, value);
}
"uint16" => {
let value: u16 =
test_case["value"].as_str().unwrap().parse::<u16>().unwrap();
bytes = ssz_encode::<u16>(&value);
// Check decoding
let decoded = decode::<u16>(&test_vector_bytes).unwrap();
assert_eq!(decoded, value);
}
"uint32" => {
let value: u32 =
test_case["value"].as_str().unwrap().parse::<u32>().unwrap();
bytes = ssz_encode::<u32>(&value);
// Check decoding
let decoded = decode::<u32>(&test_vector_bytes).unwrap();
assert_eq!(decoded, value);
}
"uint64" => {
let value: u64 =
test_case["value"].as_str().unwrap().parse::<u64>().unwrap();
bytes = ssz_encode::<u64>(&value);
// Check decoding
let decoded = decode::<u64>(&test_vector_bytes).unwrap();
assert_eq!(decoded, value);
}
_ => continue,
};
assert_eq!(test_vector_bytes, bytes);
}
}
}
#[test]
pub fn test_vector_uint_random() {
let mut file = {
let mut file_path_buf = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
file_path_buf.push("src/test_vectors/uint_random.yaml");
File::open(file_path_buf).unwrap()
};
let mut yaml_str = String::new();
file.read_to_string(&mut yaml_str).unwrap();
let docs = yaml::YamlLoader::load_from_str(&yaml_str).unwrap();
let doc = &docs[0];
// Load test cases
let test_cases = doc["test_cases"].clone();
for test_case in test_cases {
// Only the valid cases are checked as parse::<uX>() will fail for all invalid cases
if test_case["valid"].as_bool().unwrap() {
// Convert test vector 'ssz' encoded yaml to Vec<u8>
let ssz = test_case["ssz"].as_str().unwrap().trim_start_matches("0x");
let test_vector_bytes = hex::decode(ssz).unwrap();
// Convert test vector 'value' to ssz encoded bytes
let mut bytes: Vec<u8>;
match test_case["type"].as_str().unwrap() {
"uint8" => {
let value: u8 = test_case["value"].as_str().unwrap().parse::<u8>().unwrap();
bytes = ssz_encode::<u8>(&value); // check encoding
// Check decoding
let decoded = decode::<u8>(&test_vector_bytes).unwrap();
assert_eq!(decoded, value);
}
"uint16" => {
let value: u16 =
test_case["value"].as_str().unwrap().parse::<u16>().unwrap();
bytes = ssz_encode::<u16>(&value);
// Check decoding
let decoded = decode::<u16>(&test_vector_bytes).unwrap();
assert_eq!(decoded, value);
}
"uint32" => {
let value: u32 =
test_case["value"].as_str().unwrap().parse::<u32>().unwrap();
bytes = ssz_encode::<u32>(&value);
// Check decoding
let decoded = decode::<u32>(&test_vector_bytes).unwrap();
assert_eq!(decoded, value);
}
"uint64" => {
let value: u64 =
test_case["value"].as_str().unwrap().parse::<u64>().unwrap();
bytes = ssz_encode::<u64>(&value);
// Check decoding
let decoded = decode::<u64>(&test_vector_bytes).unwrap();
assert_eq!(decoded, value);
}
_ => continue,
};
assert_eq!(test_vector_bytes, bytes);
}
}
}
#[test]
pub fn test_vector_uint_wrong_length() {
let mut file = {
let mut file_path_buf = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
file_path_buf.push("src/test_vectors/uint_wrong_length.yaml");
File::open(file_path_buf).unwrap()
};
let mut yaml_str = String::new();
file.read_to_string(&mut yaml_str).unwrap();
let docs = yaml::YamlLoader::load_from_str(&yaml_str).unwrap();
let doc = &docs[0];
// Load test cases
let test_cases = doc["test_cases"].clone();
for test_case in test_cases {
// Convert test vector 'ssz' encoded yaml to Vec<u8>
let ssz = test_case["ssz"].as_str().unwrap().trim_start_matches("0x");
let test_vector_bytes = hex::decode(ssz).unwrap();
// Attempt to decode invalid ssz bytes
match test_case["type"].as_str().unwrap() {
"uint8" => {
let decoded = decode::<u8>(&test_vector_bytes);
assert!(decoded.is_err());
}
"uint16" => {
let decoded = decode::<u16>(&test_vector_bytes);
assert!(decoded.is_err());
}
"uint32" => {
let decoded = decode::<u32>(&test_vector_bytes);
assert!(decoded.is_err());
}
"uint64" => {
let decoded = decode::<u64>(&test_vector_bytes);
assert!(decoded.is_err());
}
_ => continue,
};
}
}
}
*/