proxmox-backup/src/backup/data_blob.rs
2019-08-14 12:35:53 +02:00

934 lines
33 KiB
Rust

use failure::*;
use std::convert::TryInto;
use proxmox::tools::io::{ReadExt, WriteExt};
const MAX_BLOB_SIZE: usize = 128*1024*1024;
use super::*;
/// Data blob binary storage format
///
/// Data blobs store arbitrary binary data (< 128MB), and can be
/// compressed and encrypted. A simply binary format is used to store
/// them on disk or transfer them over the network. Please use index
/// files to store large data files (".fidx" of ".didx").
///
pub struct DataBlob {
raw_data: Vec<u8>, // tagged, compressed, encryped data
}
impl DataBlob {
/// accessor to raw_data field
pub fn raw_data(&self) -> &[u8] {
&self.raw_data
}
/// Consume self and returns raw_data
pub fn into_inner(self) -> Vec<u8> {
self.raw_data
}
/// accessor to chunk type (magic number)
pub fn magic(&self) -> &[u8; 8] {
self.raw_data[0..8].try_into().unwrap()
}
/// accessor to crc32 checksum
pub fn crc(&self) -> u32 {
let crc_o = proxmox::tools::offsetof!(DataBlobHeader, crc);
u32::from_le_bytes(self.raw_data[crc_o..crc_o+4].try_into().unwrap())
}
// set the CRC checksum field
pub fn set_crc(&mut self, crc: u32) {
let crc_o = proxmox::tools::offsetof!(DataBlobHeader, crc);
self.raw_data[crc_o..crc_o+4].copy_from_slice(&crc.to_le_bytes());
}
/// compute the CRC32 checksum
pub fn compute_crc(&self) -> u32 {
let mut hasher = crc32fast::Hasher::new();
let start = header_size(self.magic()); // start after HEAD
hasher.update(&self.raw_data[start..]);
hasher.finalize()
}
/// verify the CRC32 checksum
pub fn verify_crc(&self) -> Result<(), Error> {
let expected_crc = self.compute_crc();
if expected_crc != self.crc() {
bail!("Data blob has wrong CRC checksum.");
}
Ok(())
}
/// Create a DataBlob, optionally compressed and/or encrypted
pub fn encode(
data: &[u8],
config: Option<&CryptConfig>,
compress: bool,
) -> Result<Self, Error> {
if data.len() > MAX_BLOB_SIZE {
bail!("data blob too large ({} bytes).", data.len());
}
let mut blob = if let Some(config) = config {
let compr_data;
let (_compress, data, magic) = if compress {
compr_data = zstd::block::compress(data, 1)?;
// Note: We only use compression if result is shorter
if compr_data.len() < data.len() {
(true, &compr_data[..], ENCR_COMPR_BLOB_MAGIC_1_0)
} else {
(false, data, ENCRYPTED_BLOB_MAGIC_1_0)
}
} else {
(false, data, ENCRYPTED_BLOB_MAGIC_1_0)
};
let header_len = std::mem::size_of::<EncryptedDataBlobHeader>();
let mut raw_data = Vec::with_capacity(data.len() + header_len);
let dummy_head = EncryptedDataBlobHeader {
head: DataBlobHeader { magic: [0u8; 8], crc: [0; 4] },
iv: [0u8; 16],
tag: [0u8; 16],
};
unsafe {
raw_data.write_le_value(dummy_head)?;
}
let (iv, tag) = config.encrypt_to(data, &mut raw_data)?;
let head = EncryptedDataBlobHeader {
head: DataBlobHeader { magic, crc: [0; 4] }, iv, tag,
};
unsafe {
(&mut raw_data[0..header_len]).write_le_value(head)?;
}
DataBlob { raw_data }
} else {
let max_data_len = data.len() + std::mem::size_of::<DataBlobHeader>();
if compress {
let mut comp_data = Vec::with_capacity(max_data_len);
let head = DataBlobHeader {
magic: COMPRESSED_BLOB_MAGIC_1_0,
crc: [0; 4],
};
unsafe {
comp_data.write_le_value(head)?;
}
zstd::stream::copy_encode(data, &mut comp_data, 1)?;
if comp_data.len() < max_data_len {
let mut blob = DataBlob { raw_data: comp_data };
blob.set_crc(blob.compute_crc());
return Ok(blob);
}
}
let mut raw_data = Vec::with_capacity(max_data_len);
let head = DataBlobHeader {
magic: UNCOMPRESSED_BLOB_MAGIC_1_0,
crc: [0; 4],
};
unsafe {
raw_data.write_le_value(head)?;
}
raw_data.extend_from_slice(data);
DataBlob { raw_data }
};
blob.set_crc(blob.compute_crc());
Ok(blob)
}
/// Decode blob data
pub fn decode(self, config: Option<&CryptConfig>) -> Result<Vec<u8>, Error> {
let magic = self.magic();
if magic == &UNCOMPRESSED_BLOB_MAGIC_1_0 {
let data_start = std::mem::size_of::<DataBlobHeader>();
return Ok(self.raw_data[data_start..].to_vec());
} else if magic == &COMPRESSED_BLOB_MAGIC_1_0 {
let data_start = std::mem::size_of::<DataBlobHeader>();
let data = zstd::block::decompress(&self.raw_data[data_start..], MAX_BLOB_SIZE)?;
return Ok(data);
} else if magic == &ENCR_COMPR_BLOB_MAGIC_1_0 || magic == &ENCRYPTED_BLOB_MAGIC_1_0 {
let header_len = std::mem::size_of::<EncryptedDataBlobHeader>();
let head = unsafe {
(&self.raw_data[..header_len]).read_le_value::<EncryptedDataBlobHeader>()?
};
if let Some(config) = config {
let data = if magic == &ENCR_COMPR_BLOB_MAGIC_1_0 {
config.decode_compressed_chunk(&self.raw_data[header_len..], &head.iv, &head.tag)?
} else {
config.decode_uncompressed_chunk(&self.raw_data[header_len..], &head.iv, &head.tag)?
};
return Ok(data);
} else {
bail!("unable to decrypt blob - missing CryptConfig");
}
} else if magic == &AUTH_COMPR_BLOB_MAGIC_1_0 || magic == &AUTHENTICATED_BLOB_MAGIC_1_0 {
let header_len = std::mem::size_of::<AuthenticatedDataBlobHeader>();
let head = unsafe {
(&self.raw_data[..header_len]).read_le_value::<AuthenticatedDataBlobHeader>()?
};
let data_start = std::mem::size_of::<AuthenticatedDataBlobHeader>();
// Note: only verify if we have a crypt config
if let Some(config) = config {
let signature = config.compute_auth_tag(&self.raw_data[data_start..]);
if signature != head.tag {
bail!("verifying blob signature failed");
}
}
if magic == &AUTH_COMPR_BLOB_MAGIC_1_0 {
let data = zstd::block::decompress(&self.raw_data[data_start..], 16*1024*1024)?;
return Ok(data);
} else {
return Ok(self.raw_data[data_start..].to_vec());
}
} else {
bail!("Invalid blob magic number.");
}
}
/// Create a signed DataBlob, optionally compressed
pub fn create_signed(
data: &[u8],
config: &CryptConfig,
compress: bool,
) -> Result<Self, Error> {
if data.len() > MAX_BLOB_SIZE {
bail!("data blob too large ({} bytes).", data.len());
}
let compr_data;
let (_compress, data, magic) = if compress {
compr_data = zstd::block::compress(data, 1)?;
// Note: We only use compression if result is shorter
if compr_data.len() < data.len() {
(true, &compr_data[..], AUTH_COMPR_BLOB_MAGIC_1_0)
} else {
(false, data, AUTHENTICATED_BLOB_MAGIC_1_0)
}
} else {
(false, data, AUTHENTICATED_BLOB_MAGIC_1_0)
};
let header_len = std::mem::size_of::<AuthenticatedDataBlobHeader>();
let mut raw_data = Vec::with_capacity(data.len() + header_len);
let head = AuthenticatedDataBlobHeader {
head: DataBlobHeader { magic, crc: [0; 4] },
tag: config.compute_auth_tag(data),
};
unsafe {
raw_data.write_le_value(head)?;
}
raw_data.extend_from_slice(data);
let mut blob = DataBlob { raw_data };
blob.set_crc(blob.compute_crc());
return Ok(blob);
}
/// Create Instance from raw data
pub fn from_raw(data: Vec<u8>) -> Result<Self, Error> {
if data.len() < std::mem::size_of::<DataBlobHeader>() {
bail!("blob too small ({} bytes).", data.len());
}
let magic = &data[0..8];
if magic == ENCR_COMPR_BLOB_MAGIC_1_0 || magic == ENCRYPTED_BLOB_MAGIC_1_0 {
if data.len() < std::mem::size_of::<EncryptedDataBlobHeader>() {
bail!("encrypted blob too small ({} bytes).", data.len());
}
let blob = DataBlob { raw_data: data };
Ok(blob)
} else if magic == COMPRESSED_BLOB_MAGIC_1_0 || magic == UNCOMPRESSED_BLOB_MAGIC_1_0 {
let blob = DataBlob { raw_data: data };
Ok(blob)
} else if magic == AUTH_COMPR_BLOB_MAGIC_1_0 || magic == AUTHENTICATED_BLOB_MAGIC_1_0 {
if data.len() < std::mem::size_of::<AuthenticatedDataBlobHeader>() {
bail!("authenticated blob too small ({} bytes).", data.len());
}
let blob = DataBlob { raw_data: data };
Ok(blob)
} else {
bail!("unable to parse raw blob - wrong magic");
}
}
}
use std::io::{Read, BufRead, BufReader, Write, Seek, SeekFrom};
struct CryptReader<R> {
reader: R,
small_read_buf: Vec<u8>,
block_size: usize,
crypter: openssl::symm::Crypter,
finalized: bool,
}
impl <R: BufRead> CryptReader<R> {
fn new(reader: R, iv: [u8; 16], tag: [u8; 16], config: &CryptConfig) -> Result<Self, Error> {
let block_size = config.cipher().block_size(); // Note: block size is normally 1 byte for stream ciphers
if block_size.count_ones() != 1 || block_size > 512 {
bail!("unexpected Cipher block size {}", block_size);
}
let mut crypter = config.data_crypter(&iv, openssl::symm::Mode::Decrypt)?;
crypter.set_tag(&tag)?;
Ok(Self { reader, crypter, block_size, finalized: false, small_read_buf: Vec::new() })
}
fn finish(self) -> Result<R, Error> {
if !self.finalized {
bail!("CryptReader not successfully finalized.");
}
Ok(self.reader)
}
}
impl <R: BufRead> Read for CryptReader<R> {
fn read(&mut self, buf: &mut [u8]) -> Result<usize, std::io::Error> {
if self.small_read_buf.len() > 0 {
let max = if self.small_read_buf.len() > buf.len() { buf.len() } else { self.small_read_buf.len() };
let rest = self.small_read_buf.split_off(max);
buf[..max].copy_from_slice(&self.small_read_buf);
self.small_read_buf = rest;
return Ok(max);
}
let data = self.reader.fill_buf()?;
// handle small read buffers
if buf.len() <= 2*self.block_size {
let mut outbuf = [0u8; 1024];
let count = if data.len() == 0 { // EOF
let written = self.crypter.finalize(&mut outbuf)?;
self.finalized = true;
written
} else {
let mut read_size = outbuf.len() - self.block_size;
if read_size > data.len() {
read_size = data.len();
}
let written = self.crypter.update(&data[..read_size], &mut outbuf)?;
self.reader.consume(read_size);
written
};
if count > buf.len() {
buf.copy_from_slice(&outbuf[..buf.len()]);
self.small_read_buf = outbuf[buf.len()..count].to_vec();
return Ok(buf.len());
} else {
buf[..count].copy_from_slice(&outbuf[..count]);
return Ok(count);
}
} else {
if data.len() == 0 { // EOF
let rest = self.crypter.finalize(buf)?;
self.finalized = true;
return Ok(rest)
} else {
let mut read_size = buf.len() - self.block_size;
if read_size > data.len() {
read_size = data.len();
}
let count = self.crypter.update(&data[..read_size], buf)?;
self.reader.consume(read_size);
return Ok(count)
}
}
}
}
struct CryptWriter<W> {
writer: W,
block_size: usize,
encr_buf: [u8; 64*1024],
iv: [u8; 16],
crypter: openssl::symm::Crypter,
}
impl <W: Write> CryptWriter<W> {
fn new(writer: W, config: &CryptConfig) -> Result<Self, Error> {
let mut iv = [0u8; 16];
proxmox::sys::linux::fill_with_random_data(&mut iv)?;
let block_size = config.cipher().block_size();
let crypter = config.data_crypter(&iv, openssl::symm::Mode::Encrypt)?;
Ok(Self { writer, iv, crypter, block_size, encr_buf: [0u8; 64*1024] })
}
fn finish(mut self) -> Result<(W, [u8; 16], [u8; 16]), Error> {
let rest = self.crypter.finalize(&mut self.encr_buf)?;
if rest > 0 {
self.writer.write_all(&self.encr_buf[..rest])?;
}
self.writer.flush()?;
let mut tag = [0u8; 16];
self.crypter.get_tag(&mut tag)?;
Ok((self.writer, self.iv, tag))
}
}
impl <W: Write> Write for CryptWriter<W> {
fn write(&mut self, buf: &[u8]) -> Result<usize, std::io::Error> {
let mut write_size = buf.len();
if write_size > (self.encr_buf.len() - self.block_size) {
write_size = self.encr_buf.len() - self.block_size;
}
let count = self.crypter.update(&buf[..write_size], &mut self.encr_buf)
.map_err(|err| {
std::io::Error::new(
std::io::ErrorKind::Other,
format!("crypter update failed - {}", err))
})?;
self.writer.write_all(&self.encr_buf[..count])?;
Ok(write_size)
}
fn flush(&mut self) -> Result<(), std::io::Error> {
Ok(())
}
}
struct ChecksumWriter<'a, W> {
writer: W,
hasher: crc32fast::Hasher,
signer: Option<openssl::sign::Signer<'a>>,
}
impl <'a, W: Write> ChecksumWriter<'a, W> {
fn new(writer: W, signer: Option<openssl::sign::Signer<'a>>) -> Self {
let hasher = crc32fast::Hasher::new();
Self { writer, hasher, signer }
}
pub fn finish(mut self) -> Result<(W, u32, Option<[u8; 32]>), Error> {
let crc = self.hasher.finalize();
if let Some(ref mut signer) = self.signer {
let mut tag = [0u8; 32];
signer.sign(&mut tag)?;
Ok((self.writer, crc, Some(tag)))
} else {
Ok((self.writer, crc, None))
}
}
}
impl <'a, W: Write> Write for ChecksumWriter<'a, W> {
fn write(&mut self, buf: &[u8]) -> Result<usize, std::io::Error> {
self.hasher.update(buf);
if let Some(ref mut signer) = self.signer {
signer.update(buf)
.map_err(|err| {
std::io::Error::new(
std::io::ErrorKind::Other,
format!("hmac update failed - {}", err))
})?;
}
self.writer.write(buf)
}
fn flush(&mut self) -> Result<(), std::io::Error> {
self.writer.flush()
}
}
enum BlobWriterState<'a, W: Write> {
Uncompressed { csum_writer: ChecksumWriter<'a, W> },
Compressed { compr: zstd::stream::write::Encoder<ChecksumWriter<'a, W>> },
Signed { csum_writer: ChecksumWriter<'a, W> },
SignedCompressed { compr: zstd::stream::write::Encoder<ChecksumWriter<'a, W>> },
Encrypted { crypt_writer: CryptWriter<ChecksumWriter<'a, W>> },
EncryptedCompressed { compr: zstd::stream::write::Encoder<CryptWriter<ChecksumWriter<'a, W>>> },
}
/// Write compressed data blobs
pub struct DataBlobWriter<'a, W: Write> {
state: BlobWriterState<'a, W>,
}
impl <'a, W: Write + Seek> DataBlobWriter<'a, W> {
pub fn new_uncompressed(mut writer: W) -> Result<Self, Error> {
writer.seek(SeekFrom::Start(0))?;
let head = DataBlobHeader { magic: UNCOMPRESSED_BLOB_MAGIC_1_0, crc: [0; 4] };
unsafe {
writer.write_le_value(head)?;
}
let csum_writer = ChecksumWriter::new(writer, None);
Ok(Self { state: BlobWriterState::Uncompressed { csum_writer }})
}
pub fn new_compressed(mut writer: W) -> Result<Self, Error> {
writer.seek(SeekFrom::Start(0))?;
let head = DataBlobHeader { magic: COMPRESSED_BLOB_MAGIC_1_0, crc: [0; 4] };
unsafe {
writer.write_le_value(head)?;
}
let csum_writer = ChecksumWriter::new(writer, None);
let compr = zstd::stream::write::Encoder::new(csum_writer, 1)?;
Ok(Self { state: BlobWriterState::Compressed { compr }})
}
pub fn new_signed(mut writer: W, config: &'a CryptConfig) -> Result<Self, Error> {
writer.seek(SeekFrom::Start(0))?;
let head = AuthenticatedDataBlobHeader {
head: DataBlobHeader { magic: AUTHENTICATED_BLOB_MAGIC_1_0, crc: [0; 4] },
tag: [0u8; 32],
};
unsafe {
writer.write_le_value(head)?;
}
let signer = config.data_signer();
let csum_writer = ChecksumWriter::new(writer, Some(signer));
Ok(Self { state: BlobWriterState::Signed { csum_writer }})
}
pub fn new_signed_compressed(mut writer: W, config: &'a CryptConfig) -> Result<Self, Error> {
writer.seek(SeekFrom::Start(0))?;
let head = AuthenticatedDataBlobHeader {
head: DataBlobHeader { magic: AUTH_COMPR_BLOB_MAGIC_1_0, crc: [0; 4] },
tag: [0u8; 32],
};
unsafe {
writer.write_le_value(head)?;
}
let signer = config.data_signer();
let csum_writer = ChecksumWriter::new(writer, Some(signer));
let compr = zstd::stream::write::Encoder::new(csum_writer, 1)?;
Ok(Self { state: BlobWriterState::SignedCompressed { compr }})
}
pub fn new_encrypted(mut writer: W, config: &'a CryptConfig) -> Result<Self, Error> {
writer.seek(SeekFrom::Start(0))?;
let head = EncryptedDataBlobHeader {
head: DataBlobHeader { magic: ENCRYPTED_BLOB_MAGIC_1_0, crc: [0; 4] },
iv: [0u8; 16],
tag: [0u8; 16],
};
unsafe {
writer.write_le_value(head)?;
}
let csum_writer = ChecksumWriter::new(writer, None);
let crypt_writer = CryptWriter::new(csum_writer, config)?;
Ok(Self { state: BlobWriterState::Encrypted { crypt_writer }})
}
pub fn new_encrypted_compressed(mut writer: W, config: &'a CryptConfig) -> Result<Self, Error> {
writer.seek(SeekFrom::Start(0))?;
let head = EncryptedDataBlobHeader {
head: DataBlobHeader { magic: ENCR_COMPR_BLOB_MAGIC_1_0, crc: [0; 4] },
iv: [0u8; 16],
tag: [0u8; 16],
};
unsafe {
writer.write_le_value(head)?;
}
let csum_writer = ChecksumWriter::new(writer, None);
let crypt_writer = CryptWriter::new(csum_writer, config)?;
let compr = zstd::stream::write::Encoder::new(crypt_writer, 1)?;
Ok(Self { state: BlobWriterState::EncryptedCompressed { compr }})
}
pub fn finish(self) -> Result<W, Error> {
match self.state {
BlobWriterState::Uncompressed { csum_writer } => {
// write CRC
let (mut writer, crc, _) = csum_writer.finish()?;
let head = DataBlobHeader { magic: UNCOMPRESSED_BLOB_MAGIC_1_0, crc: crc.to_le_bytes() };
writer.seek(SeekFrom::Start(0))?;
unsafe {
writer.write_le_value(head)?;
}
return Ok(writer)
}
BlobWriterState::Compressed { compr } => {
let csum_writer = compr.finish()?;
let (mut writer, crc, _) = csum_writer.finish()?;
let head = DataBlobHeader { magic: COMPRESSED_BLOB_MAGIC_1_0, crc: crc.to_le_bytes() };
writer.seek(SeekFrom::Start(0))?;
unsafe {
writer.write_le_value(head)?;
}
return Ok(writer)
}
BlobWriterState::Signed { csum_writer } => {
let (mut writer, crc, tag) = csum_writer.finish()?;
let head = AuthenticatedDataBlobHeader {
head: DataBlobHeader { magic: AUTHENTICATED_BLOB_MAGIC_1_0, crc: crc.to_le_bytes() },
tag: tag.unwrap(),
};
writer.seek(SeekFrom::Start(0))?;
unsafe {
writer.write_le_value(head)?;
}
return Ok(writer)
}
BlobWriterState::SignedCompressed { compr } => {
let csum_writer = compr.finish()?;
let (mut writer, crc, tag) = csum_writer.finish()?;
let head = AuthenticatedDataBlobHeader {
head: DataBlobHeader { magic: AUTH_COMPR_BLOB_MAGIC_1_0, crc: crc.to_le_bytes() },
tag: tag.unwrap(),
};
writer.seek(SeekFrom::Start(0))?;
unsafe {
writer.write_le_value(head)?;
}
return Ok(writer)
}
BlobWriterState::Encrypted { crypt_writer } => {
let (csum_writer, iv, tag) = crypt_writer.finish()?;
let (mut writer, crc, _) = csum_writer.finish()?;
let head = EncryptedDataBlobHeader {
head: DataBlobHeader { magic: ENCRYPTED_BLOB_MAGIC_1_0, crc: crc.to_le_bytes() },
iv, tag,
};
writer.seek(SeekFrom::Start(0))?;
unsafe {
writer.write_le_value(head)?;
}
return Ok(writer)
}
BlobWriterState::EncryptedCompressed { compr } => {
let crypt_writer = compr.finish()?;
let (csum_writer, iv, tag) = crypt_writer.finish()?;
let (mut writer, crc, _) = csum_writer.finish()?;
let head = EncryptedDataBlobHeader {
head: DataBlobHeader { magic: ENCR_COMPR_BLOB_MAGIC_1_0, crc: crc.to_le_bytes() },
iv, tag,
};
writer.seek(SeekFrom::Start(0))?;
unsafe {
writer.write_le_value(head)?;
}
return Ok(writer)
}
}
}
}
impl <'a, W: Write + Seek> Write for DataBlobWriter<'a, W> {
fn write(&mut self, buf: &[u8]) -> Result<usize, std::io::Error> {
match self.state {
BlobWriterState::Uncompressed { ref mut csum_writer } => {
csum_writer.write(buf)
}
BlobWriterState::Compressed { ref mut compr } => {
compr.write(buf)
}
BlobWriterState::Signed { ref mut csum_writer } => {
csum_writer.write(buf)
}
BlobWriterState::SignedCompressed { ref mut compr } => {
compr.write(buf)
}
BlobWriterState::Encrypted { ref mut crypt_writer } => {
crypt_writer.write(buf)
}
BlobWriterState::EncryptedCompressed { ref mut compr } => {
compr.write(buf)
}
}
}
fn flush(&mut self) -> Result<(), std::io::Error> {
match self.state {
BlobWriterState::Uncompressed { ref mut csum_writer } => {
csum_writer.flush()
}
BlobWriterState::Compressed { ref mut compr } => {
compr.flush()
}
BlobWriterState::Signed { ref mut csum_writer } => {
csum_writer.flush()
}
BlobWriterState::SignedCompressed { ref mut compr } => {
compr.flush()
}
BlobWriterState::Encrypted { ref mut crypt_writer } => {
crypt_writer.flush()
}
BlobWriterState::EncryptedCompressed { ref mut compr } => {
compr.flush()
}
}
}
}
struct ChecksumReader<'a, R> {
reader: R,
hasher: crc32fast::Hasher,
signer: Option<openssl::sign::Signer<'a>>,
}
impl <'a, R: Read> ChecksumReader<'a, R> {
fn new(reader: R, signer: Option<openssl::sign::Signer<'a>>) -> Self {
let hasher = crc32fast::Hasher::new();
Self { reader, hasher, signer }
}
pub fn finish(mut self) -> Result<(R, u32, Option<[u8; 32]>), Error> {
let crc = self.hasher.finalize();
if let Some(ref mut signer) = self.signer {
let mut tag = [0u8; 32];
signer.sign(&mut tag)?;
Ok((self.reader, crc, Some(tag)))
} else {
Ok((self.reader, crc, None))
}
}
}
impl <'a, R: Read> Read for ChecksumReader<'a, R> {
fn read(&mut self, buf: &mut [u8]) -> Result<usize, std::io::Error> {
let count = self.reader.read(buf)?;
if count > 0 {
self.hasher.update(&buf[..count]);
if let Some(ref mut signer) = self.signer {
signer.update(&buf[..count])
.map_err(|err| {
std::io::Error::new(
std::io::ErrorKind::Other,
format!("hmac update failed - {}", err))
})?;
}
}
Ok(count)
}
}
enum BlobReaderState<'a, R: Read> {
Uncompressed { expected_crc: u32, csum_reader: ChecksumReader<'a, R> },
Compressed { expected_crc: u32, decompr: zstd::stream::read::Decoder<BufReader<ChecksumReader<'a, R>>> },
Signed { expected_crc: u32, expected_hmac: [u8; 32], csum_reader: ChecksumReader<'a, R> },
SignedCompressed { expected_crc: u32, expected_hmac: [u8; 32], decompr: zstd::stream::read::Decoder<BufReader<ChecksumReader<'a, R>>> },
Encrypted { expected_crc: u32, decrypt_reader: CryptReader<BufReader<ChecksumReader<'a, R>>> },
EncryptedCompressed { expected_crc: u32, decompr: zstd::stream::read::Decoder<BufReader<CryptReader<BufReader<ChecksumReader<'a, R>>>>> },
}
/// Read data blobs
pub struct DataBlobReader<'a, R: Read> {
state: BlobReaderState<'a, R>,
}
impl <'a, R: Read> DataBlobReader<'a, R> {
pub fn new(mut reader: R, config: Option<&'a CryptConfig>) -> Result<Self, Error> {
let head: DataBlobHeader = unsafe { reader.read_le_value()? };
match head.magic {
UNCOMPRESSED_BLOB_MAGIC_1_0 => {
let expected_crc = u32::from_le_bytes(head.crc);
let csum_reader = ChecksumReader::new(reader, None);
Ok(Self { state: BlobReaderState::Uncompressed { expected_crc, csum_reader }})
}
COMPRESSED_BLOB_MAGIC_1_0 => {
let expected_crc = u32::from_le_bytes(head.crc);
let csum_reader = ChecksumReader::new(reader, None);
let decompr = zstd::stream::read::Decoder::new(csum_reader)?;
Ok(Self { state: BlobReaderState::Compressed { expected_crc, decompr }})
}
AUTHENTICATED_BLOB_MAGIC_1_0 => {
let expected_crc = u32::from_le_bytes(head.crc);
let mut expected_hmac = [0u8; 32];
reader.read_exact(&mut expected_hmac)?;
let signer = config.map(|c| c.data_signer());
let csum_reader = ChecksumReader::new(reader, signer);
Ok(Self { state: BlobReaderState::Signed { expected_crc, expected_hmac, csum_reader }})
}
AUTH_COMPR_BLOB_MAGIC_1_0 => {
let expected_crc = u32::from_le_bytes(head.crc);
let mut expected_hmac = [0u8; 32];
reader.read_exact(&mut expected_hmac)?;
let signer = config.map(|c| c.data_signer());
let csum_reader = ChecksumReader::new(reader, signer);
let decompr = zstd::stream::read::Decoder::new(csum_reader)?;
Ok(Self { state: BlobReaderState::SignedCompressed { expected_crc, expected_hmac, decompr }})
}
ENCRYPTED_BLOB_MAGIC_1_0 => {
let expected_crc = u32::from_le_bytes(head.crc);
let mut iv = [0u8; 16];
let mut expected_tag = [0u8; 16];
reader.read_exact(&mut iv)?;
reader.read_exact(&mut expected_tag)?;
let csum_reader = ChecksumReader::new(reader, None);
let decrypt_reader = CryptReader::new(BufReader::with_capacity(64*1024, csum_reader), iv, expected_tag, config.unwrap())?;
Ok(Self { state: BlobReaderState::Encrypted { expected_crc, decrypt_reader }})
}
ENCR_COMPR_BLOB_MAGIC_1_0 => {
let expected_crc = u32::from_le_bytes(head.crc);
let mut iv = [0u8; 16];
let mut expected_tag = [0u8; 16];
reader.read_exact(&mut iv)?;
reader.read_exact(&mut expected_tag)?;
let csum_reader = ChecksumReader::new(reader, None);
let decrypt_reader = CryptReader::new(BufReader::with_capacity(64*1024, csum_reader), iv, expected_tag, config.unwrap())?;
let decompr = zstd::stream::read::Decoder::new(decrypt_reader)?;
Ok(Self { state: BlobReaderState::EncryptedCompressed { expected_crc, decompr }})
}
_ => bail!("got wrong magic number {:?}", head.magic)
}
}
pub fn finish(self) -> Result<R, Error> {
match self.state {
BlobReaderState::Uncompressed { csum_reader, expected_crc } => {
let (reader, crc, _) = csum_reader.finish()?;
if crc != expected_crc {
bail!("blob crc check failed");
}
Ok(reader)
}
BlobReaderState::Compressed { expected_crc, decompr } => {
let csum_reader = decompr.finish().into_inner();
let (reader, crc, _) = csum_reader.finish()?;
if crc != expected_crc {
bail!("blob crc check failed");
}
Ok(reader)
}
BlobReaderState::Signed { csum_reader, expected_crc, expected_hmac } => {
let (reader, crc, hmac) = csum_reader.finish()?;
if crc != expected_crc {
bail!("blob crc check failed");
}
if let Some(hmac) = hmac {
if hmac != expected_hmac {
bail!("blob signature check failed");
}
}
Ok(reader)
}
BlobReaderState::SignedCompressed { expected_crc, expected_hmac, decompr } => {
let csum_reader = decompr.finish().into_inner();
let (reader, crc, hmac) = csum_reader.finish()?;
if crc != expected_crc {
bail!("blob crc check failed");
}
if let Some(hmac) = hmac {
if hmac != expected_hmac {
bail!("blob signature check failed");
}
}
Ok(reader)
}
BlobReaderState::Encrypted { expected_crc, decrypt_reader } => {
let csum_reader = decrypt_reader.finish()?.into_inner();
let (reader, crc, _) = csum_reader.finish()?;
if crc != expected_crc {
bail!("blob crc check failed");
}
Ok(reader)
}
BlobReaderState::EncryptedCompressed { expected_crc, decompr } => {
let decrypt_reader = decompr.finish().into_inner();
let csum_reader = decrypt_reader.finish()?.into_inner();
let (reader, crc, _) = csum_reader.finish()?;
if crc != expected_crc {
bail!("blob crc check failed");
}
Ok(reader)
}
}
}
}
impl <'a, R: BufRead> Read for DataBlobReader<'a, R> {
fn read(&mut self, buf: &mut [u8]) -> Result<usize, std::io::Error> {
match &mut self.state {
BlobReaderState::Uncompressed { csum_reader, .. } => {
csum_reader.read(buf)
}
BlobReaderState::Compressed { decompr, .. } => {
decompr.read(buf)
}
BlobReaderState::Signed { csum_reader, .. } => {
csum_reader.read(buf)
}
BlobReaderState::SignedCompressed { decompr, .. } => {
decompr.read(buf)
}
BlobReaderState::Encrypted { decrypt_reader, .. } => {
decrypt_reader.read(buf)
}
BlobReaderState::EncryptedCompressed { decompr, .. } => {
decompr.read(buf)
}
}
}
}