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#![forbid(unsafe_code, missing_debug_implementations, missing_docs)]
#![cfg_attr(test, deny(warnings))]
#[macro_use]
extern crate failure;
extern crate byteorder;
mod file_type;
mod hash_type;
mod protocol_version;
use self::byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
use failure::Error;
use std::io::Cursor;
pub use file_type::FileType;
pub use hash_type::HashType;
pub use protocol_version::ProtocolVersion;
const VERIFY_TRAILING_ZEROS: bool = false;
const HEADER_LENGTH: usize = 32;
const MAX_ALGORITHM_NAME_LENGTH: usize = HEADER_LENGTH - 8;
#[derive(Debug)]
pub struct Header {
pub file_type: FileType,
pub protocol_version: ProtocolVersion,
pub entry_size: u16,
pub hash_type: HashType,
}
impl Header {
pub fn new(
file_type: FileType,
entry_size: u16,
hash_type: HashType,
) -> Self {
Header {
file_type,
entry_size,
hash_type,
protocol_version: ProtocolVersion::V0,
}
}
pub fn from_vec(buffer: &[u8]) -> Result<Header, Error> {
ensure!(buffer.len() == 32, "buffer should be 32 bytes");
let mut rdr = Cursor::new(buffer);
let byte = rdr.read_u8().unwrap();
ensure!(
byte == 5,
"The first byte of a SLEEP header should be '5', found {}",
byte
);
let byte = rdr.read_u8().unwrap();
ensure!(
byte == 2,
"The second byte of a SLEEP header should be '2', found {}",
byte
);
let byte = rdr.read_u8().unwrap();
ensure!(
byte == 87,
"The third byte of a SLEEP header should be '87', found {}",
byte
);
let file_type = match rdr.read_u8().unwrap() {
0 => FileType::BitField,
1 => FileType::Signatures,
2 => FileType::Tree,
num => bail!(
"The fourth byte '{}' does not belong to any known SLEEP file type",
num
),
};
let protocol_version = match rdr.read_u8().unwrap() {
0 => ProtocolVersion::V0,
num => bail!(
"The fifth byte '{}' does not belong to any known SLEEP protocol protocol_version",
num
),
};
let entry_size = rdr.read_u16::<BigEndian>().unwrap();
let hash_name_len = rdr.read_u8().unwrap() as usize;
let current = rdr.position() as usize;
ensure!(
hash_name_len <= MAX_ALGORITHM_NAME_LENGTH,
"Algorithm name is too long: {} (max: {})",
hash_name_len,
MAX_ALGORITHM_NAME_LENGTH
);
let hash_name_upper = current + hash_name_len;
ensure!(
buffer.len() >= hash_name_upper,
"Broken parser: algorithm name is out of bounds: {} {}",
hash_name_upper,
buffer.len()
);
let buf_slice = &buffer[current..hash_name_upper];
rdr.set_position(hash_name_upper as u64 + 1);
let algo = ::std::str::from_utf8(buf_slice).map_err(|e| {
format_err!("The algorithm string was invalid utf8 encoded: {:?}", e)
})?;
let hash_type = match algo {
"BLAKE2b" => HashType::BLAKE2b,
"Ed25519" => HashType::Ed25519,
"" => HashType::None,
name => bail!("Unexpected algorithm name: {}", name),
};
if VERIFY_TRAILING_ZEROS {
for index in rdr.position()..32 {
let byte = rdr.read_u8().unwrap();
ensure!(
byte == 0,
"The remainder of the header should be zero-filled. Found byte '{}' at position '{}'.",
byte, index
);
}
}
Ok(Header {
protocol_version,
entry_size,
file_type,
hash_type,
})
}
pub fn to_vec(&self) -> Vec<u8> {
let mut wtr = Vec::with_capacity(32);
wtr.extend_from_slice(&[5u8, 2, 87]);
let file_type = match self.file_type {
FileType::BitField => 0,
FileType::Signatures => 1,
FileType::Tree => 2,
};
wtr.write_u8(file_type).unwrap();
let protocol_version = match self.protocol_version {
ProtocolVersion::V0 => 0,
};
wtr.write_u8(protocol_version).unwrap();
wtr.write_u16::<BigEndian>(self.entry_size).unwrap();
let hash_type = match self.hash_type {
HashType::BLAKE2b => "BLAKE2b",
HashType::Ed25519 => "Ed25519",
HashType::None => "",
};
let hash_type = hash_type.as_bytes();
wtr.write_u8(hash_type.len() as u8).unwrap();
wtr.extend_from_slice(hash_type);
for _ in wtr.len()..wtr.capacity() {
wtr.write_u8(0).unwrap();
}
wtr
}
pub fn is_bitfield(&self) -> bool {
self.entry_size == 3328
&& self.file_type.is_bitfield()
&& self.hash_type.is_none()
}
pub fn is_signatures(&self) -> bool {
self.entry_size == 64
&& self.file_type.is_signatures()
&& self.hash_type.is_ed25519()
}
pub fn is_tree(&self) -> bool {
self.entry_size == 40
&& self.file_type.is_tree()
&& self.hash_type.is_blake2b()
}
}
pub fn create_bitfield() -> Header {
Header::new(FileType::BitField, 3328, HashType::None)
}
pub fn create_signatures() -> Header {
Header::new(FileType::Signatures, 64, HashType::Ed25519)
}
pub fn create_tree() -> Header {
Header::new(FileType::Tree, 40, HashType::BLAKE2b)
}