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use std::{
cmp,
io::{self, Read as _},
iter,
};
use rand::{Rng as _, RngCore as _};
use super::decoder::{DecoderReader, BUF_SIZE};
use crate::{
alphabet,
engine::{general_purpose::STANDARD, Engine, GeneralPurpose},
tests::{random_alphabet, random_config, random_engine},
DecodeError, PAD_BYTE,
};
#[test]
fn simple() {
let tests: &[(&[u8], &[u8])] = &[
(&b"0"[..], &b"MA=="[..]),
(b"01", b"MDE="),
(b"012", b"MDEy"),
(b"0123", b"MDEyMw=="),
(b"01234", b"MDEyMzQ="),
(b"012345", b"MDEyMzQ1"),
(b"0123456", b"MDEyMzQ1Ng=="),
(b"01234567", b"MDEyMzQ1Njc="),
(b"012345678", b"MDEyMzQ1Njc4"),
(b"0123456789", b"MDEyMzQ1Njc4OQ=="),
][..];
for (text_expected, base64data) in tests.iter() {
// Read n bytes at a time.
for n in 1..base64data.len() + 1 {
let mut wrapped_reader = io::Cursor::new(base64data);
let mut decoder = DecoderReader::new(&mut wrapped_reader, &STANDARD);
// handle errors as you normally would
let mut text_got = Vec::new();
let mut buffer = vec![0u8; n];
while let Ok(read) = decoder.read(&mut buffer[..]) {
if read == 0 {
break;
}
text_got.extend_from_slice(&buffer[..read]);
}
assert_eq!(
text_got,
*text_expected,
"\nGot: {}\nExpected: {}",
String::from_utf8_lossy(&text_got[..]),
String::from_utf8_lossy(text_expected)
);
}
}
}
// Make sure we error out on trailing junk.
#[test]
fn trailing_junk() {
let tests: &[&[u8]] = &[&b"MDEyMzQ1Njc4*!@#$%^&"[..], b"MDEyMzQ1Njc4OQ== "][..];
for base64data in tests.iter() {
// Read n bytes at a time.
for n in 1..base64data.len() + 1 {
let mut wrapped_reader = io::Cursor::new(base64data);
let mut decoder = DecoderReader::new(&mut wrapped_reader, &STANDARD);
// handle errors as you normally would
let mut buffer = vec![0u8; n];
let mut saw_error = false;
loop {
match decoder.read(&mut buffer[..]) {
Err(_) => {
saw_error = true;
break;
}
Ok(read) if read == 0 => break,
Ok(_) => (),
}
}
assert!(saw_error);
}
}
}
#[test]
fn handles_short_read_from_delegate() {
let mut rng = rand::thread_rng();
let mut bytes = Vec::new();
let mut b64 = String::new();
let mut decoded = Vec::new();
for _ in 0..10_000 {
bytes.clear();
b64.clear();
decoded.clear();
let size = rng.gen_range(0..(10 * BUF_SIZE));
bytes.extend(iter::repeat(0).take(size));
bytes.truncate(size);
rng.fill_bytes(&mut bytes[..size]);
assert_eq!(size, bytes.len());
let engine = random_engine(&mut rng);
engine.encode_string(&bytes[..], &mut b64);
let mut wrapped_reader = io::Cursor::new(b64.as_bytes());
let mut short_reader = RandomShortRead {
delegate: &mut wrapped_reader,
rng: &mut rng,
};
let mut decoder = DecoderReader::new(&mut short_reader, &engine);
let decoded_len = decoder.read_to_end(&mut decoded).unwrap();
assert_eq!(size, decoded_len);
assert_eq!(&bytes[..], &decoded[..]);
}
}
#[test]
fn read_in_short_increments() {
let mut rng = rand::thread_rng();
let mut bytes = Vec::new();
let mut b64 = String::new();
let mut decoded = Vec::new();
for _ in 0..10_000 {
bytes.clear();
b64.clear();
decoded.clear();
let size = rng.gen_range(0..(10 * BUF_SIZE));
bytes.extend(iter::repeat(0).take(size));
// leave room to play around with larger buffers
decoded.extend(iter::repeat(0).take(size * 3));
rng.fill_bytes(&mut bytes[..]);
assert_eq!(size, bytes.len());
let engine = random_engine(&mut rng);
engine.encode_string(&bytes[..], &mut b64);
let mut wrapped_reader = io::Cursor::new(&b64[..]);
let mut decoder = DecoderReader::new(&mut wrapped_reader, &engine);
consume_with_short_reads_and_validate(&mut rng, &bytes[..], &mut decoded, &mut decoder);
}
}
#[test]
fn read_in_short_increments_with_short_delegate_reads() {
let mut rng = rand::thread_rng();
let mut bytes = Vec::new();
let mut b64 = String::new();
let mut decoded = Vec::new();
for _ in 0..10_000 {
bytes.clear();
b64.clear();
decoded.clear();
let size = rng.gen_range(0..(10 * BUF_SIZE));
bytes.extend(iter::repeat(0).take(size));
// leave room to play around with larger buffers
decoded.extend(iter::repeat(0).take(size * 3));
rng.fill_bytes(&mut bytes[..]);
assert_eq!(size, bytes.len());
let engine = random_engine(&mut rng);
engine.encode_string(&bytes[..], &mut b64);
let mut base_reader = io::Cursor::new(&b64[..]);
let mut decoder = DecoderReader::new(&mut base_reader, &engine);
let mut short_reader = RandomShortRead {
delegate: &mut decoder,
rng: &mut rand::thread_rng(),
};
consume_with_short_reads_and_validate(
&mut rng,
&bytes[..],
&mut decoded,
&mut short_reader,
);
}
}
#[test]
fn reports_invalid_last_symbol_correctly() {
let mut rng = rand::thread_rng();
let mut bytes = Vec::new();
let mut b64 = String::new();
let mut b64_bytes = Vec::new();
let mut decoded = Vec::new();
let mut bulk_decoded = Vec::new();
for _ in 0..1_000 {
bytes.clear();
b64.clear();
b64_bytes.clear();
let size = rng.gen_range(1..(10 * BUF_SIZE));
bytes.extend(iter::repeat(0).take(size));
decoded.extend(iter::repeat(0).take(size));
rng.fill_bytes(&mut bytes[..]);
assert_eq!(size, bytes.len());
let config = random_config(&mut rng);
let alphabet = random_alphabet(&mut rng);
// changing padding will cause invalid padding errors when we twiddle the last byte
let engine = GeneralPurpose::new(alphabet, config.with_encode_padding(false));
engine.encode_string(&bytes[..], &mut b64);
b64_bytes.extend(b64.bytes());
assert_eq!(b64_bytes.len(), b64.len());
// change the last character to every possible symbol. Should behave the same as bulk
// decoding whether invalid or valid.
for &s1 in alphabet.symbols.iter() {
decoded.clear();
bulk_decoded.clear();
// replace the last
*b64_bytes.last_mut().unwrap() = s1;
let bulk_res = engine.decode_vec(&b64_bytes[..], &mut bulk_decoded);
let mut wrapped_reader = io::Cursor::new(&b64_bytes[..]);
let mut decoder = DecoderReader::new(&mut wrapped_reader, &engine);
let stream_res = decoder.read_to_end(&mut decoded).map(|_| ()).map_err(|e| {
e.into_inner()
.and_then(|e| e.downcast::<DecodeError>().ok())
});
assert_eq!(bulk_res.map_err(|e| Some(Box::new(e))), stream_res);
}
}
}
#[test]
fn reports_invalid_byte_correctly() {
let mut rng = rand::thread_rng();
let mut bytes = Vec::new();
let mut b64 = String::new();
let mut stream_decoded = Vec::new();
let mut bulk_decoded = Vec::new();
for _ in 0..10_000 {
bytes.clear();
b64.clear();
stream_decoded.clear();
bulk_decoded.clear();
let size = rng.gen_range(1..(10 * BUF_SIZE));
bytes.extend(iter::repeat(0).take(size));
rng.fill_bytes(&mut bytes[..size]);
assert_eq!(size, bytes.len());
let engine = GeneralPurpose::new(&alphabet::STANDARD, random_config(&mut rng));
engine.encode_string(&bytes[..], &mut b64);
// replace one byte, somewhere, with '*', which is invalid
let bad_byte_pos = rng.gen_range(0..b64.len());
let mut b64_bytes = b64.bytes().collect::<Vec<u8>>();
b64_bytes[bad_byte_pos] = b'*';
let mut wrapped_reader = io::Cursor::new(b64_bytes.clone());
let mut decoder = DecoderReader::new(&mut wrapped_reader, &engine);
let read_decode_err = decoder
.read_to_end(&mut stream_decoded)
.map_err(|e| {
let kind = e.kind();
let inner = e
.into_inner()
.and_then(|e| e.downcast::<DecodeError>().ok());
inner.map(|i| (*i, kind))
})
.err()
.and_then(|o| o);
let bulk_decode_err = engine.decode_vec(&b64_bytes[..], &mut bulk_decoded).err();
// it's tricky to predict where the invalid data's offset will be since if it's in the last
// chunk it will be reported at the first padding location because it's treated as invalid
// padding. So, we just check that it's the same as it is for decoding all at once.
assert_eq!(
bulk_decode_err.map(|e| (e, io::ErrorKind::InvalidData)),
read_decode_err
);
}
}
#[test]
fn internal_padding_error_with_short_read_concatenated_texts_invalid_byte_error() {
let mut rng = rand::thread_rng();
let mut bytes = Vec::new();
let mut b64 = String::new();
let mut reader_decoded = Vec::new();
let mut bulk_decoded = Vec::new();
// encodes with padding, requires that padding be present so we don't get InvalidPadding
// just because padding is there at all
let engine = STANDARD;
for _ in 0..10_000 {
bytes.clear();
b64.clear();
reader_decoded.clear();
bulk_decoded.clear();
// at least 2 bytes so there can be a split point between bytes
let size = rng.gen_range(2..(10 * BUF_SIZE));
bytes.resize(size, 0);
rng.fill_bytes(&mut bytes[..size]);
// Concatenate two valid b64s, yielding padding in the middle.
// This avoids scenarios that are challenging to assert on, like random padding location
// that might be InvalidLastSymbol when decoded at certain buffer sizes but InvalidByte
// when done all at once.
let split = loop {
// find a split point that will produce padding on the first part
let s = rng.gen_range(1..size);
if s % 3 != 0 {
// short enough to need padding
break s;
};
};
engine.encode_string(&bytes[..split], &mut b64);
assert!(b64.contains('='), "split: {}, b64: {}", split, b64);
let bad_byte_pos = b64.find('=').unwrap();
engine.encode_string(&bytes[split..], &mut b64);
let b64_bytes = b64.as_bytes();
// short read to make it plausible for padding to happen on a read boundary
let read_len = rng.gen_range(1..10);
let mut wrapped_reader = ShortRead {
max_read_len: read_len,
delegate: io::Cursor::new(&b64_bytes),
};
let mut decoder = DecoderReader::new(&mut wrapped_reader, &engine);
let read_decode_err = decoder
.read_to_end(&mut reader_decoded)
.map_err(|e| {
*e.into_inner()
.and_then(|e| e.downcast::<DecodeError>().ok())
.unwrap()
})
.unwrap_err();
let bulk_decode_err = engine.decode_vec(b64_bytes, &mut bulk_decoded).unwrap_err();
assert_eq!(
bulk_decode_err,
read_decode_err,
"read len: {}, bad byte pos: {}, b64: {}",
read_len,
bad_byte_pos,
std::str::from_utf8(b64_bytes).unwrap()
);
assert_eq!(
DecodeError::InvalidByte(
split / 3 * 4
+ match split % 3 {
1 => 2,
2 => 3,
_ => unreachable!(),
},
PAD_BYTE
),
read_decode_err
);
}
}
#[test]
fn internal_padding_anywhere_error() {
let mut rng = rand::thread_rng();
let mut bytes = Vec::new();
let mut b64 = String::new();
let mut reader_decoded = Vec::new();
// encodes with padding, requires that padding be present so we don't get InvalidPadding
// just because padding is there at all
let engine = STANDARD;
for _ in 0..10_000 {
bytes.clear();
b64.clear();
reader_decoded.clear();
bytes.resize(10 * BUF_SIZE, 0);
rng.fill_bytes(&mut bytes[..]);
// Just shove a padding byte in there somewhere.
// The specific error to expect is challenging to predict precisely because it
// will vary based on the position of the padding in the quad and the read buffer
// length, but SOMETHING should go wrong.
engine.encode_string(&bytes[..], &mut b64);
let mut b64_bytes = b64.as_bytes().to_vec();
// put padding somewhere other than the last quad
b64_bytes[rng.gen_range(0..bytes.len() - 4)] = PAD_BYTE;
// short read to make it plausible for padding to happen on a read boundary
let read_len = rng.gen_range(1..10);
let mut wrapped_reader = ShortRead {
max_read_len: read_len,
delegate: io::Cursor::new(&b64_bytes),
};
let mut decoder = DecoderReader::new(&mut wrapped_reader, &engine);
let result = decoder.read_to_end(&mut reader_decoded);
assert!(result.is_err());
}
}
fn consume_with_short_reads_and_validate<R: io::Read>(
rng: &mut rand::rngs::ThreadRng,
expected_bytes: &[u8],
decoded: &mut [u8],
short_reader: &mut R,
) {
let mut total_read = 0_usize;
loop {
assert!(
total_read <= expected_bytes.len(),
"tr {} size {}",
total_read,
expected_bytes.len()
);
if total_read == expected_bytes.len() {
assert_eq!(expected_bytes, &decoded[..total_read]);
// should be done
assert_eq!(0, short_reader.read(&mut *decoded).unwrap());
// didn't write anything
assert_eq!(expected_bytes, &decoded[..total_read]);
break;
}
let decode_len = rng.gen_range(1..cmp::max(2, expected_bytes.len() * 2));
let read = short_reader
.read(&mut decoded[total_read..total_read + decode_len])
.unwrap();
total_read += read;
}
}
/// Limits how many bytes a reader will provide in each read call.
/// Useful for shaking out code that may work fine only with typical input sources that always fill
/// the buffer.
struct RandomShortRead<'a, 'b, R: io::Read, N: rand::Rng> {
delegate: &'b mut R,
rng: &'a mut N,
}
impl<'a, 'b, R: io::Read, N: rand::Rng> io::Read for RandomShortRead<'a, 'b, R, N> {
fn read(&mut self, buf: &mut [u8]) -> Result<usize, io::Error> {
// avoid 0 since it means EOF for non-empty buffers
let effective_len = cmp::min(self.rng.gen_range(1..20), buf.len());
self.delegate.read(&mut buf[..effective_len])
}
}
struct ShortRead<R: io::Read> {
delegate: R,
max_read_len: usize,
}
impl<R: io::Read> io::Read for ShortRead<R> {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
let len = self.max_read_len.max(buf.len());
self.delegate.read(&mut buf[..len])
}
}