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// rstest_reuse template functions have unused variables
#![allow(unused_variables)]
use rand::{
self,
distributions::{self, Distribution as _},
rngs, Rng as _, SeedableRng as _,
};
use rstest::rstest;
use rstest_reuse::{apply, template};
use std::{collections, fmt, io::Read as _};
use crate::{
alphabet::{Alphabet, STANDARD},
encode::add_padding,
encoded_len,
engine::{
general_purpose, naive, Config, DecodeEstimate, DecodeMetadata, DecodePaddingMode, Engine,
},
read::DecoderReader,
tests::{assert_encode_sanity, random_alphabet, random_config},
DecodeError, PAD_BYTE,
};
// the case::foo syntax includes the "foo" in the generated test method names
#[template]
#[rstest(engine_wrapper,
case::general_purpose(GeneralPurposeWrapper {}),
case::naive(NaiveWrapper {}),
case::decoder_reader(DecoderReaderEngineWrapper {}),
)]
fn all_engines<E: EngineWrapper>(engine_wrapper: E) {}
/// Some decode tests don't make sense for use with `DecoderReader` as they are difficult to
/// reason about or otherwise inapplicable given how DecoderReader slice up its input along
/// chunk boundaries.
#[template]
#[rstest(engine_wrapper,
case::general_purpose(GeneralPurposeWrapper {}),
case::naive(NaiveWrapper {}),
)]
fn all_engines_except_decoder_reader<E: EngineWrapper>(engine_wrapper: E) {}
#[apply(all_engines)]
fn rfc_test_vectors_std_alphabet<E: EngineWrapper>(engine_wrapper: E) {
let data = vec![
("", ""),
("f", "Zg=="),
("fo", "Zm8="),
("foo", "Zm9v"),
("foob", "Zm9vYg=="),
("fooba", "Zm9vYmE="),
("foobar", "Zm9vYmFy"),
];
let engine = E::standard();
let engine_no_padding = E::standard_unpadded();
for (orig, encoded) in &data {
let encoded_without_padding = encoded.trim_end_matches('=');
// unpadded
{
let mut encode_buf = [0_u8; 8];
let mut decode_buf = [0_u8; 6];
let encode_len =
engine_no_padding.internal_encode(orig.as_bytes(), &mut encode_buf[..]);
assert_eq!(
&encoded_without_padding,
&std::str::from_utf8(&encode_buf[0..encode_len]).unwrap()
);
let decode_len = engine_no_padding
.decode_slice_unchecked(encoded_without_padding.as_bytes(), &mut decode_buf[..])
.unwrap();
assert_eq!(orig.len(), decode_len);
assert_eq!(
orig,
&std::str::from_utf8(&decode_buf[0..decode_len]).unwrap()
);
// if there was any padding originally, the no padding engine won't decode it
if encoded.as_bytes().contains(&PAD_BYTE) {
assert_eq!(
Err(DecodeError::InvalidPadding),
engine_no_padding.decode(encoded)
)
}
}
// padded
{
let mut encode_buf = [0_u8; 8];
let mut decode_buf = [0_u8; 6];
let encode_len = engine.internal_encode(orig.as_bytes(), &mut encode_buf[..]);
assert_eq!(
// doesn't have padding added yet
&encoded_without_padding,
&std::str::from_utf8(&encode_buf[0..encode_len]).unwrap()
);
let pad_len = add_padding(encode_len, &mut encode_buf[encode_len..]);
assert_eq!(encoded.as_bytes(), &encode_buf[..encode_len + pad_len]);
let decode_len = engine
.decode_slice_unchecked(encoded.as_bytes(), &mut decode_buf[..])
.unwrap();
assert_eq!(orig.len(), decode_len);
assert_eq!(
orig,
&std::str::from_utf8(&decode_buf[0..decode_len]).unwrap()
);
// if there was (canonical) padding, and we remove it, the standard engine won't decode
if encoded.as_bytes().contains(&PAD_BYTE) {
assert_eq!(
Err(DecodeError::InvalidPadding),
engine.decode(encoded_without_padding)
)
}
}
}
}
#[apply(all_engines)]
fn roundtrip_random<E: EngineWrapper>(engine_wrapper: E) {
let mut rng = seeded_rng();
let mut orig_data = Vec::<u8>::new();
let mut encode_buf = Vec::<u8>::new();
let mut decode_buf = Vec::<u8>::new();
let len_range = distributions::Uniform::new(1, 1_000);
for _ in 0..10_000 {
let engine = E::random(&mut rng);
orig_data.clear();
encode_buf.clear();
decode_buf.clear();
let (orig_len, _, encoded_len) = generate_random_encoded_data(
&engine,
&mut orig_data,
&mut encode_buf,
&mut rng,
&len_range,
);
// exactly the right size
decode_buf.resize(orig_len, 0);
let dec_len = engine
.decode_slice_unchecked(&encode_buf[0..encoded_len], &mut decode_buf[..])
.unwrap();
assert_eq!(orig_len, dec_len);
assert_eq!(&orig_data[..], &decode_buf[..dec_len]);
}
}
#[apply(all_engines)]
fn encode_doesnt_write_extra_bytes<E: EngineWrapper>(engine_wrapper: E) {
let mut rng = seeded_rng();
let mut orig_data = Vec::<u8>::new();
let mut encode_buf = Vec::<u8>::new();
let mut encode_buf_backup = Vec::<u8>::new();
let input_len_range = distributions::Uniform::new(0, 1000);
for _ in 0..10_000 {
let engine = E::random(&mut rng);
let padded = engine.config().encode_padding();
orig_data.clear();
encode_buf.clear();
encode_buf_backup.clear();
let orig_len = fill_rand(&mut orig_data, &mut rng, &input_len_range);
let prefix_len = 1024;
// plenty of prefix and suffix
fill_rand_len(&mut encode_buf, &mut rng, prefix_len * 2 + orig_len * 2);
encode_buf_backup.extend_from_slice(&encode_buf[..]);
let expected_encode_len_no_pad = encoded_len(orig_len, false).unwrap();
let encoded_len_no_pad =
engine.internal_encode(&orig_data[..], &mut encode_buf[prefix_len..]);
assert_eq!(expected_encode_len_no_pad, encoded_len_no_pad);
// no writes past what it claimed to write
assert_eq!(&encode_buf_backup[..prefix_len], &encode_buf[..prefix_len]);
assert_eq!(
&encode_buf_backup[(prefix_len + encoded_len_no_pad)..],
&encode_buf[(prefix_len + encoded_len_no_pad)..]
);
let encoded_data = &encode_buf[prefix_len..(prefix_len + encoded_len_no_pad)];
assert_encode_sanity(
std::str::from_utf8(encoded_data).unwrap(),
// engines don't pad
false,
orig_len,
);
// pad so we can decode it in case our random engine requires padding
let pad_len = if padded {
add_padding(
encoded_len_no_pad,
&mut encode_buf[prefix_len + encoded_len_no_pad..],
)
} else {
0
};
assert_eq!(
orig_data,
engine
.decode(&encode_buf[prefix_len..(prefix_len + encoded_len_no_pad + pad_len)],)
.unwrap()
);
}
}
#[apply(all_engines)]
fn encode_engine_slice_fits_into_precisely_sized_slice<E: EngineWrapper>(engine_wrapper: E) {
let mut orig_data = Vec::new();
let mut encoded_data = Vec::new();
let mut decoded = Vec::new();
let input_len_range = distributions::Uniform::new(0, 1000);
let mut rng = rngs::SmallRng::from_entropy();
for _ in 0..10_000 {
orig_data.clear();
encoded_data.clear();
decoded.clear();
let input_len = input_len_range.sample(&mut rng);
for _ in 0..input_len {
orig_data.push(rng.gen());
}
let engine = E::random(&mut rng);
let encoded_size = encoded_len(input_len, engine.config().encode_padding()).unwrap();
encoded_data.resize(encoded_size, 0);
assert_eq!(
encoded_size,
engine.encode_slice(&orig_data, &mut encoded_data).unwrap()
);
assert_encode_sanity(
std::str::from_utf8(&encoded_data[0..encoded_size]).unwrap(),
engine.config().encode_padding(),
input_len,
);
engine
.decode_vec(&encoded_data[0..encoded_size], &mut decoded)
.unwrap();
assert_eq!(orig_data, decoded);
}
}
#[apply(all_engines)]
fn decode_doesnt_write_extra_bytes<E>(engine_wrapper: E)
where
E: EngineWrapper,
<<E as EngineWrapper>::Engine as Engine>::Config: fmt::Debug,
{
let mut rng = seeded_rng();
let mut orig_data = Vec::<u8>::new();
let mut encode_buf = Vec::<u8>::new();
let mut decode_buf = Vec::<u8>::new();
let mut decode_buf_backup = Vec::<u8>::new();
let len_range = distributions::Uniform::new(1, 1_000);
for _ in 0..10_000 {
let engine = E::random(&mut rng);
orig_data.clear();
encode_buf.clear();
decode_buf.clear();
decode_buf_backup.clear();
let orig_len = fill_rand(&mut orig_data, &mut rng, &len_range);
encode_buf.resize(orig_len * 2 + 100, 0);
let encoded_len = engine
.encode_slice(&orig_data[..], &mut encode_buf[..])
.unwrap();
encode_buf.truncate(encoded_len);
// oversize decode buffer so we can easily tell if it writes anything more than
// just the decoded data
let prefix_len = 1024;
// plenty of prefix and suffix
fill_rand_len(&mut decode_buf, &mut rng, prefix_len * 2 + orig_len * 2);
decode_buf_backup.extend_from_slice(&decode_buf[..]);
let dec_len = engine
.decode_slice_unchecked(&encode_buf, &mut decode_buf[prefix_len..])
.unwrap();
assert_eq!(orig_len, dec_len);
assert_eq!(
&orig_data[..],
&decode_buf[prefix_len..prefix_len + dec_len]
);
assert_eq!(&decode_buf_backup[..prefix_len], &decode_buf[..prefix_len]);
assert_eq!(
&decode_buf_backup[prefix_len + dec_len..],
&decode_buf[prefix_len + dec_len..]
);
}
}
#[apply(all_engines)]
fn decode_detect_invalid_last_symbol<E: EngineWrapper>(engine_wrapper: E) {
// 0xFF -> "/w==", so all letters > w, 0-9, and '+', '/' should get InvalidLastSymbol
let engine = E::standard();
assert_eq!(Ok(vec![0x89, 0x85]), engine.decode("iYU="));
assert_eq!(Ok(vec![0xFF]), engine.decode("/w=="));
for (suffix, offset) in vec![
// suffix, offset of bad byte from start of suffix
("/x==", 1_usize),
("/z==", 1_usize),
("/0==", 1_usize),
("/9==", 1_usize),
("/+==", 1_usize),
("//==", 1_usize),
// trailing 01
("iYV=", 2_usize),
// trailing 10
("iYW=", 2_usize),
// trailing 11
("iYX=", 2_usize),
] {
for prefix_quads in 0..256 {
let mut encoded = "AAAA".repeat(prefix_quads);
encoded.push_str(suffix);
assert_eq!(
Err(DecodeError::InvalidLastSymbol(
encoded.len() - 4 + offset,
suffix.as_bytes()[offset],
)),
engine.decode(encoded.as_str())
);
}
}
}
#[apply(all_engines)]
fn decode_detect_invalid_last_symbol_when_length_is_also_invalid<E: EngineWrapper>(
engine_wrapper: E,
) {
let mut rng = seeded_rng();
// check across enough lengths that it would likely cover any implementation's various internal
// small/large input division
for len in (0_usize..256).map(|len| len * 4 + 1) {
let engine = E::random_alphabet(&mut rng, &STANDARD);
let mut input = vec![b'A'; len];
// with a valid last char, it's InvalidLength
assert_eq!(Err(DecodeError::InvalidLength), engine.decode(&input));
// after mangling the last char, it's InvalidByte
input[len - 1] = b'"';
assert_eq!(
Err(DecodeError::InvalidByte(len - 1, b'"')),
engine.decode(&input)
);
}
}
#[apply(all_engines)]
fn decode_detect_invalid_last_symbol_every_possible_two_symbols<E: EngineWrapper>(
engine_wrapper: E,
) {
let engine = E::standard();
let mut base64_to_bytes = collections::HashMap::new();
for b in 0_u8..=255 {
let mut b64 = vec![0_u8; 4];
assert_eq!(2, engine.internal_encode(&[b], &mut b64[..]));
let _ = add_padding(2, &mut b64[2..]);
assert!(base64_to_bytes.insert(b64, vec![b]).is_none());
}
// every possible combination of trailing symbols must either decode to 1 byte or get InvalidLastSymbol, with or without any leading chunks
let mut prefix = Vec::new();
for _ in 0..256 {
let mut clone = prefix.clone();
let mut symbols = [0_u8; 4];
for &s1 in STANDARD.symbols.iter() {
symbols[0] = s1;
for &s2 in STANDARD.symbols.iter() {
symbols[1] = s2;
symbols[2] = PAD_BYTE;
symbols[3] = PAD_BYTE;
// chop off previous symbols
clone.truncate(prefix.len());
clone.extend_from_slice(&symbols[..]);
let decoded_prefix_len = prefix.len() / 4 * 3;
match base64_to_bytes.get(&symbols[..]) {
Some(bytes) => {
let res = engine
.decode(&clone)
// remove prefix
.map(|decoded| decoded[decoded_prefix_len..].to_vec());
assert_eq!(Ok(bytes.clone()), res);
}
None => assert_eq!(
Err(DecodeError::InvalidLastSymbol(1, s2)),
engine.decode(&symbols[..])
),
}
}
}
prefix.extend_from_slice(b"AAAA");
}
}
#[apply(all_engines)]
fn decode_detect_invalid_last_symbol_every_possible_three_symbols<E: EngineWrapper>(
engine_wrapper: E,
) {
let engine = E::standard();
let mut base64_to_bytes = collections::HashMap::new();
let mut bytes = [0_u8; 2];
for b1 in 0_u8..=255 {
bytes[0] = b1;
for b2 in 0_u8..=255 {
bytes[1] = b2;
let mut b64 = vec![0_u8; 4];
assert_eq!(3, engine.internal_encode(&bytes, &mut b64[..]));
let _ = add_padding(3, &mut b64[3..]);
let mut v = Vec::with_capacity(2);
v.extend_from_slice(&bytes[..]);
assert!(base64_to_bytes.insert(b64, v).is_none());
}
}
// every possible combination of symbols must either decode to 2 bytes or get InvalidLastSymbol, with or without any leading chunks
let mut prefix = Vec::new();
for _ in 0..256 {
let mut input = prefix.clone();
let mut symbols = [0_u8; 4];
for &s1 in STANDARD.symbols.iter() {
symbols[0] = s1;
for &s2 in STANDARD.symbols.iter() {
symbols[1] = s2;
for &s3 in STANDARD.symbols.iter() {
symbols[2] = s3;
symbols[3] = PAD_BYTE;
// chop off previous symbols
input.truncate(prefix.len());
input.extend_from_slice(&symbols[..]);
let decoded_prefix_len = prefix.len() / 4 * 3;
match base64_to_bytes.get(&symbols[..]) {
Some(bytes) => {
let res = engine
.decode(&input)
// remove prefix
.map(|decoded| decoded[decoded_prefix_len..].to_vec());
assert_eq!(Ok(bytes.clone()), res);
}
None => assert_eq!(
Err(DecodeError::InvalidLastSymbol(2, s3)),
engine.decode(&symbols[..])
),
}
}
}
}
prefix.extend_from_slice(b"AAAA");
}
}
#[apply(all_engines)]
fn decode_invalid_trailing_bits_ignored_when_configured<E: EngineWrapper>(engine_wrapper: E) {
let strict = E::standard();
let forgiving = E::standard_allow_trailing_bits();
fn assert_tolerant_decode<E: Engine>(
engine: &E,
input: &mut String,
b64_prefix_len: usize,
expected_decode_bytes: Vec<u8>,
data: &str,
) {
let prefixed = prefixed_data(input, b64_prefix_len, data);
let decoded = engine.decode(prefixed);
// prefix is always complete chunks
let decoded_prefix_len = b64_prefix_len / 4 * 3;
assert_eq!(
Ok(expected_decode_bytes),
decoded.map(|v| v[decoded_prefix_len..].to_vec())
);
}
let mut prefix = String::new();
for _ in 0..256 {
let mut input = prefix.clone();
assert!(strict
.decode(prefixed_data(&mut input, prefix.len(), "/w=="))
.is_ok());
assert!(strict
.decode(prefixed_data(&mut input, prefix.len(), "iYU="))
.is_ok());
// trailing 01
assert_tolerant_decode(&forgiving, &mut input, prefix.len(), vec![255], "/x==");
assert_tolerant_decode(&forgiving, &mut input, prefix.len(), vec![137, 133], "iYV=");
// trailing 10
assert_tolerant_decode(&forgiving, &mut input, prefix.len(), vec![255], "/y==");
assert_tolerant_decode(&forgiving, &mut input, prefix.len(), vec![137, 133], "iYW=");
// trailing 11
assert_tolerant_decode(&forgiving, &mut input, prefix.len(), vec![255], "/z==");
assert_tolerant_decode(&forgiving, &mut input, prefix.len(), vec![137, 133], "iYX=");
prefix.push_str("AAAA");
}
}
#[apply(all_engines)]
fn decode_invalid_byte_error<E: EngineWrapper>(engine_wrapper: E) {
let mut rng = seeded_rng();
let mut orig_data = Vec::<u8>::new();
let mut encode_buf = Vec::<u8>::new();
let mut decode_buf = Vec::<u8>::new();
let len_range = distributions::Uniform::new(1, 1_000);
for _ in 0..100_000 {
let alphabet = random_alphabet(&mut rng);
let engine = E::random_alphabet(&mut rng, alphabet);
orig_data.clear();
encode_buf.clear();
decode_buf.clear();
let (orig_len, encoded_len_just_data, encoded_len_with_padding) =
generate_random_encoded_data(
&engine,
&mut orig_data,
&mut encode_buf,
&mut rng,
&len_range,
);
// exactly the right size
decode_buf.resize(orig_len, 0);
// replace one encoded byte with an invalid byte
let invalid_byte: u8 = loop {
let byte: u8 = rng.gen();
if alphabet.symbols.contains(&byte) || byte == PAD_BYTE {
continue;
} else {
break byte;
}
};
let invalid_range = distributions::Uniform::new(0, orig_len);
let invalid_index = invalid_range.sample(&mut rng);
encode_buf[invalid_index] = invalid_byte;
assert_eq!(
Err(DecodeError::InvalidByte(invalid_index, invalid_byte)),
engine.decode_slice_unchecked(
&encode_buf[0..encoded_len_with_padding],
&mut decode_buf[..],
)
);
}
}
/// Any amount of padding anywhere before the final non padding character = invalid byte at first
/// pad byte.
/// From this, we know padding must extend to the end of the input.
// DecoderReader pseudo-engine detects InvalidLastSymbol instead of InvalidLength because it
// can end a decode on the quad that happens to contain the start of the padding
#[apply(all_engines_except_decoder_reader)]
fn decode_padding_before_final_non_padding_char_error_invalid_byte<E: EngineWrapper>(
engine_wrapper: E,
) {
let mut rng = seeded_rng();
// the different amounts of proper padding, w/ offset from end for the last non-padding char
let suffixes = [("/w==", 2), ("iYu=", 1), ("zzzz", 0)];
let prefix_quads_range = distributions::Uniform::from(0..=256);
for mode in all_pad_modes() {
// we don't encode so we don't care about encode padding
let engine = E::standard_with_pad_mode(true, mode);
for _ in 0..100_000 {
for (suffix, offset) in suffixes.iter() {
let mut s = "ABCD".repeat(prefix_quads_range.sample(&mut rng));
s.push_str(suffix);
let mut encoded = s.into_bytes();
// calculate a range to write padding into that leaves at least one non padding char
let last_non_padding_offset = encoded.len() - 1 - offset;
// don't include last non padding char as it must stay not padding
let padding_end = rng.gen_range(0..last_non_padding_offset);
// don't use more than 100 bytes of padding, but also use shorter lengths when
// padding_end is near the start of the encoded data to avoid biasing to padding
// the entire prefix on short lengths
let padding_len = rng.gen_range(1..=usize::min(100, padding_end + 1));
let padding_start = padding_end.saturating_sub(padding_len);
encoded[padding_start..=padding_end].fill(PAD_BYTE);
assert_eq!(
Err(DecodeError::InvalidByte(padding_start, PAD_BYTE)),
engine.decode(&encoded),
);
}
}
}
}
/// Any amount of padding before final chunk that crosses over into final chunk with 2-4 bytes =
/// invalid byte at first pad byte.
/// From this and [decode_padding_starts_before_final_chunk_error_invalid_length] we know the
/// padding must start in the final chunk.
// DecoderReader pseudo-engine detects InvalidLastSymbol instead of InvalidLength because it
// can end a decode on the quad that happens to contain the start of the padding
#[apply(all_engines_except_decoder_reader)]
fn decode_padding_starts_before_final_chunk_error_invalid_byte<E: EngineWrapper>(
engine_wrapper: E,
) {
let mut rng = seeded_rng();
// must have at least one prefix quad
let prefix_quads_range = distributions::Uniform::from(1..256);
// excluding 1 since we don't care about invalid length in this test
let suffix_pad_len_range = distributions::Uniform::from(2..=4);
for mode in all_pad_modes() {
// we don't encode so we don't care about encode padding
let engine = E::standard_with_pad_mode(true, mode);
for _ in 0..100_000 {
let suffix_len = suffix_pad_len_range.sample(&mut rng);
let mut encoded = "ABCD"
.repeat(prefix_quads_range.sample(&mut rng))
.into_bytes();
encoded.resize(encoded.len() + suffix_len, PAD_BYTE);
// amount of padding must be long enough to extend back from suffix into previous
// quads
let padding_len = rng.gen_range(suffix_len + 1..encoded.len());
// no non-padding after padding in this test, so padding goes to the end
let padding_start = encoded.len() - padding_len;
encoded[padding_start..].fill(PAD_BYTE);
assert_eq!(
Err(DecodeError::InvalidByte(padding_start, PAD_BYTE)),
engine.decode(&encoded),
"suffix_len: {}, padding_len: {}, b64: {}",
suffix_len,
padding_len,
std::str::from_utf8(&encoded).unwrap()
);
}
}
}
/// Any amount of padding before final chunk that crosses over into final chunk with 1 byte =
/// invalid length.
/// From this we know the padding must start in the final chunk.
// DecoderReader pseudo-engine detects InvalidByte instead of InvalidLength because it starts by
// decoding only the available complete quads
#[apply(all_engines_except_decoder_reader)]
fn decode_padding_starts_before_final_chunk_error_invalid_length<E: EngineWrapper>(
engine_wrapper: E,
) {
let mut rng = seeded_rng();
// must have at least one prefix quad
let prefix_quads_range = distributions::Uniform::from(1..256);
for mode in all_pad_modes() {
// we don't encode so we don't care about encode padding
let engine = E::standard_with_pad_mode(true, mode);
for _ in 0..100_000 {
let mut encoded = "ABCD"
.repeat(prefix_quads_range.sample(&mut rng))
.into_bytes();
encoded.resize(encoded.len() + 1, PAD_BYTE);
// amount of padding must be long enough to extend back from suffix into previous
// quads
let padding_len = rng.gen_range(1 + 1..encoded.len());
// no non-padding after padding in this test, so padding goes to the end
let padding_start = encoded.len() - padding_len;
encoded[padding_start..].fill(PAD_BYTE);
assert_eq!(Err(DecodeError::InvalidLength), engine.decode(&encoded),);
}
}
}
/// 0-1 bytes of data before any amount of padding in final chunk = invalid byte, since padding
/// is not valid data (consistent with error for pad bytes in earlier chunks).
/// From this we know there must be 2-3 bytes of data before padding
#[apply(all_engines)]
fn decode_too_little_data_before_padding_error_invalid_byte<E: EngineWrapper>(engine_wrapper: E) {
let mut rng = seeded_rng();
// want to test no prefix quad case, so start at 0
let prefix_quads_range = distributions::Uniform::from(0_usize..256);
let suffix_data_len_range = distributions::Uniform::from(0_usize..=1);
for mode in all_pad_modes() {
// we don't encode so we don't care about encode padding
let engine = E::standard_with_pad_mode(true, mode);
for _ in 0..100_000 {
let suffix_data_len = suffix_data_len_range.sample(&mut rng);
let prefix_quad_len = prefix_quads_range.sample(&mut rng);
// ensure there is a suffix quad
let min_padding = usize::from(suffix_data_len == 0);
// for all possible padding lengths
for padding_len in min_padding..=(4 - suffix_data_len) {
let mut encoded = "ABCD".repeat(prefix_quad_len).into_bytes();
encoded.resize(encoded.len() + suffix_data_len, b'A');
encoded.resize(encoded.len() + padding_len, PAD_BYTE);
if suffix_data_len + padding_len == 1 {
assert_eq!(Err(DecodeError::InvalidLength), engine.decode(&encoded),);
} else {
assert_eq!(
Err(DecodeError::InvalidByte(
prefix_quad_len * 4 + suffix_data_len,
PAD_BYTE,
)),
engine.decode(&encoded),
"suffix data len {} pad len {}",
suffix_data_len,
padding_len
);
}
}
}
}
}
#[apply(all_engines)]
fn decode_malleability_test_case_3_byte_suffix_valid<E: EngineWrapper>(engine_wrapper: E) {
assert_eq!(
b"Hello".as_slice(),
&E::standard().decode("SGVsbG8=").unwrap()
);
}
#[apply(all_engines)]
fn decode_malleability_test_case_3_byte_suffix_invalid_trailing_symbol<E: EngineWrapper>(
engine_wrapper: E,
) {
assert_eq!(
DecodeError::InvalidLastSymbol(6, 0x39),
E::standard().decode("SGVsbG9=").unwrap_err()
);
}
#[apply(all_engines)]
fn decode_malleability_test_case_3_byte_suffix_no_padding<E: EngineWrapper>(engine_wrapper: E) {
assert_eq!(
DecodeError::InvalidPadding,
E::standard().decode("SGVsbG9").unwrap_err()
);
}
#[apply(all_engines)]
fn decode_malleability_test_case_2_byte_suffix_valid_two_padding_symbols<E: EngineWrapper>(
engine_wrapper: E,
) {
assert_eq!(
b"Hell".as_slice(),
&E::standard().decode("SGVsbA==").unwrap()
);
}
#[apply(all_engines)]
fn decode_malleability_test_case_2_byte_suffix_short_padding<E: EngineWrapper>(engine_wrapper: E) {
assert_eq!(
DecodeError::InvalidPadding,
E::standard().decode("SGVsbA=").unwrap_err()
);
}
#[apply(all_engines)]
fn decode_malleability_test_case_2_byte_suffix_no_padding<E: EngineWrapper>(engine_wrapper: E) {
assert_eq!(
DecodeError::InvalidPadding,
E::standard().decode("SGVsbA").unwrap_err()
);
}
// DecoderReader pseudo-engine gets InvalidByte at 8 (extra padding) since it decodes the first
// two complete quads correctly.
#[apply(all_engines_except_decoder_reader)]
fn decode_malleability_test_case_2_byte_suffix_too_much_padding<E: EngineWrapper>(
engine_wrapper: E,
) {
assert_eq!(
DecodeError::InvalidByte(6, PAD_BYTE),
E::standard().decode("SGVsbA====").unwrap_err()
);
}
/// Requires canonical padding -> accepts 2 + 2, 3 + 1, 4 + 0 final quad configurations
#[apply(all_engines)]
fn decode_pad_mode_requires_canonical_accepts_canonical<E: EngineWrapper>(engine_wrapper: E) {
assert_all_suffixes_ok(
E::standard_with_pad_mode(true, DecodePaddingMode::RequireCanonical),
vec!["/w==", "iYU=", "AAAA"],
);
}
/// Requires canonical padding -> rejects 2 + 0-1, 3 + 0 final chunk configurations
#[apply(all_engines)]
fn decode_pad_mode_requires_canonical_rejects_non_canonical<E: EngineWrapper>(engine_wrapper: E) {
let engine = E::standard_with_pad_mode(true, DecodePaddingMode::RequireCanonical);
let suffixes = ["/w", "/w=", "iYU"];
for num_prefix_quads in 0..256 {
for &suffix in suffixes.iter() {
let mut encoded = "AAAA".repeat(num_prefix_quads);
encoded.push_str(suffix);
let res = engine.decode(&encoded);
assert_eq!(Err(DecodeError::InvalidPadding), res);
}
}
}
/// Requires no padding -> accepts 2 + 0, 3 + 0, 4 + 0 final chunk configuration
#[apply(all_engines)]
fn decode_pad_mode_requires_no_padding_accepts_no_padding<E: EngineWrapper>(engine_wrapper: E) {
assert_all_suffixes_ok(
E::standard_with_pad_mode(true, DecodePaddingMode::RequireNone),
vec!["/w", "iYU", "AAAA"],
);
}
/// Requires no padding -> rejects 2 + 1-2, 3 + 1 final chunk configuration
#[apply(all_engines)]
fn decode_pad_mode_requires_no_padding_rejects_any_padding<E: EngineWrapper>(engine_wrapper: E) {
let engine = E::standard_with_pad_mode(true, DecodePaddingMode::RequireNone);
let suffixes = ["/w=", "/w==", "iYU="];
for num_prefix_quads in 0..256 {
for &suffix in suffixes.iter() {
let mut encoded = "AAAA".repeat(num_prefix_quads);
encoded.push_str(suffix);
let res = engine.decode(&encoded);
assert_eq!(Err(DecodeError::InvalidPadding), res);
}
}
}
/// Indifferent padding accepts 2 + 0-2, 3 + 0-1, 4 + 0 final chunk configuration
#[apply(all_engines)]
fn decode_pad_mode_indifferent_padding_accepts_anything<E: EngineWrapper>(engine_wrapper: E) {
assert_all_suffixes_ok(
E::standard_with_pad_mode(true, DecodePaddingMode::Indifferent),
vec!["/w", "/w=", "/w==", "iYU", "iYU=", "AAAA"],
);
}
// DecoderReader pseudo-engine finds the first padding, but doesn't report it as an error,
// because in the next decode it finds more padding, which is reported as InvalidByte, just
// with an offset at its position in the second decode, rather than being linked to the start
// of the padding that was first seen in the previous decode.
#[apply(all_engines_except_decoder_reader)]
fn decode_pad_byte_in_penultimate_quad_error<E: EngineWrapper>(engine_wrapper: E) {
for mode in all_pad_modes() {
// we don't encode so we don't care about encode padding
let engine = E::standard_with_pad_mode(true, mode);
for num_prefix_quads in 0..256 {
// leave room for at least one pad byte in penultimate quad
for num_valid_bytes_penultimate_quad in 0..4 {
// can't have 1 or it would be invalid length
for num_pad_bytes_in_final_quad in 2..=4 {
let mut s: String = "ABCD".repeat(num_prefix_quads);
// varying amounts of padding in the penultimate quad
for _ in 0..num_valid_bytes_penultimate_quad {
s.push('A');
}
// finish penultimate quad with padding
for _ in num_valid_bytes_penultimate_quad..4 {
s.push('=');
}
// and more padding in the final quad
for _ in 0..num_pad_bytes_in_final_quad {
s.push('=');
}
// padding should be an invalid byte before the final quad.
// Could argue that the *next* padding byte (in the next quad) is technically the first
// erroneous one, but reporting that accurately is more complex and probably nobody cares
assert_eq!(
DecodeError::InvalidByte(
num_prefix_quads * 4 + num_valid_bytes_penultimate_quad,
b'=',
),
engine.decode(&s).unwrap_err(),
);
}
}
}
}
}
#[apply(all_engines)]
fn decode_bytes_after_padding_in_final_quad_error<E: EngineWrapper>(engine_wrapper: E) {
for mode in all_pad_modes() {
// we don't encode so we don't care about encode padding
let engine = E::standard_with_pad_mode(true, mode);
for num_prefix_quads in 0..256 {
// leave at least one byte in the quad for padding
for bytes_after_padding in 1..4 {
let mut s: String = "ABCD".repeat(num_prefix_quads);
// every invalid padding position with a 3-byte final quad: 1 to 3 bytes after padding
for _ in 0..(3 - bytes_after_padding) {
s.push('A');
}
s.push('=');
for _ in 0..bytes_after_padding {
s.push('A');
}
// First (and only) padding byte is invalid.
assert_eq!(
DecodeError::InvalidByte(
num_prefix_quads * 4 + (3 - bytes_after_padding),
b'='
),
engine.decode(&s).unwrap_err()
);
}
}
}
}
#[apply(all_engines)]
fn decode_absurd_pad_error<E: EngineWrapper>(engine_wrapper: E) {
for mode in all_pad_modes() {
// we don't encode so we don't care about encode padding
let engine = E::standard_with_pad_mode(true, mode);
for num_prefix_quads in 0..256 {
let mut s: String = "ABCD".repeat(num_prefix_quads);
s.push_str("==Y=Wx===pY=2U=====");
// first padding byte
assert_eq!(
DecodeError::InvalidByte(num_prefix_quads * 4, b'='),
engine.decode(&s).unwrap_err()
);
}
}
}
// DecoderReader pseudo-engine detects InvalidByte instead of InvalidLength because it starts by
// decoding only the available complete quads
#[apply(all_engines_except_decoder_reader)]
fn decode_too_much_padding_returns_error<E: EngineWrapper>(engine_wrapper: E) {
for mode in all_pad_modes() {
// we don't encode so we don't care about encode padding
let engine = E::standard_with_pad_mode(true, mode);
for num_prefix_quads in 0..256 {
// add enough padding to ensure that we'll hit all decode stages at the different lengths
for pad_bytes in 1..=64 {
let mut s: String = "ABCD".repeat(num_prefix_quads);
let padding: String = "=".repeat(pad_bytes);
s.push_str(&padding);
if pad_bytes % 4 == 1 {
assert_eq!(DecodeError::InvalidLength, engine.decode(&s).unwrap_err());
} else {
assert_eq!(
DecodeError::InvalidByte(num_prefix_quads * 4, b'='),
engine.decode(&s).unwrap_err()
);
}
}
}
}
}
// DecoderReader pseudo-engine detects InvalidByte instead of InvalidLength because it starts by
// decoding only the available complete quads
#[apply(all_engines_except_decoder_reader)]
fn decode_padding_followed_by_non_padding_returns_error<E: EngineWrapper>(engine_wrapper: E) {
for mode in all_pad_modes() {
// we don't encode so we don't care about encode padding
let engine = E::standard_with_pad_mode(true, mode);
for num_prefix_quads in 0..256 {
for pad_bytes in 0..=32 {
let mut s: String = "ABCD".repeat(num_prefix_quads);
let padding: String = "=".repeat(pad_bytes);
s.push_str(&padding);
s.push('E');
if pad_bytes % 4 == 0 {
assert_eq!(DecodeError::InvalidLength, engine.decode(&s).unwrap_err());
} else {
assert_eq!(
DecodeError::InvalidByte(num_prefix_quads * 4, b'='),
engine.decode(&s).unwrap_err()
);
}
}
}
}
}
#[apply(all_engines)]
fn decode_one_char_in_final_quad_with_padding_error<E: EngineWrapper>(engine_wrapper: E) {
for mode in all_pad_modes() {
// we don't encode so we don't care about encode padding
let engine = E::standard_with_pad_mode(true, mode);
for num_prefix_quads in 0..256 {
let mut s: String = "ABCD".repeat(num_prefix_quads);
s.push_str("E=");
assert_eq!(
DecodeError::InvalidByte(num_prefix_quads * 4 + 1, b'='),
engine.decode(&s).unwrap_err()
);
// more padding doesn't change the error
s.push('=');
assert_eq!(
DecodeError::InvalidByte(num_prefix_quads * 4 + 1, b'='),
engine.decode(&s).unwrap_err()
);
s.push('=');
assert_eq!(
DecodeError::InvalidByte(num_prefix_quads * 4 + 1, b'='),
engine.decode(&s).unwrap_err()
);
}
}
}
#[apply(all_engines)]
fn decode_too_few_symbols_in_final_quad_error<E: EngineWrapper>(engine_wrapper: E) {
for mode in all_pad_modes() {
// we don't encode so we don't care about encode padding
let engine = E::standard_with_pad_mode(true, mode);
for num_prefix_quads in 0..256 {
// <2 is invalid
for final_quad_symbols in 0..2 {
for padding_symbols in 0..=(4 - final_quad_symbols) {
let mut s: String = "ABCD".repeat(num_prefix_quads);
for _ in 0..final_quad_symbols {
s.push('A');
}
for _ in 0..padding_symbols {
s.push('=');
}
match final_quad_symbols + padding_symbols {
0 => continue,
1 => {
assert_eq!(DecodeError::InvalidLength, engine.decode(&s).unwrap_err());
}
_ => {
// error reported at first padding byte
assert_eq!(
DecodeError::InvalidByte(
num_prefix_quads * 4 + final_quad_symbols,
b'=',
),
engine.decode(&s).unwrap_err()
);
}
}
}
}
}
}
}
// DecoderReader pseudo-engine can't handle DecodePaddingMode::RequireNone since it will decode
// a complete quad with padding in it before encountering the stray byte that makes it an invalid
// length
#[apply(all_engines_except_decoder_reader)]
fn decode_invalid_trailing_bytes<E: EngineWrapper>(engine_wrapper: E) {
for mode in all_pad_modes() {
do_invalid_trailing_byte(E::standard_with_pad_mode(true, mode), mode);
}
}
#[apply(all_engines)]
fn decode_invalid_trailing_bytes_all_modes<E: EngineWrapper>(engine_wrapper: E) {
// excluding no padding mode because the DecoderWrapper pseudo-engine will fail with
// InvalidPadding because it will decode the last complete quad with padding first
for mode in pad_modes_allowing_padding() {
do_invalid_trailing_byte(E::standard_with_pad_mode(true, mode), mode);
}
}
#[apply(all_engines)]
fn decode_invalid_trailing_padding_as_invalid_length<E: EngineWrapper>(engine_wrapper: E) {
// excluding no padding mode because the DecoderWrapper pseudo-engine will fail with
// InvalidPadding because it will decode the last complete quad with padding first
for mode in pad_modes_allowing_padding() {
do_invalid_trailing_padding_as_invalid_length(E::standard_with_pad_mode(true, mode), mode);
}
}
// DecoderReader pseudo-engine can't handle DecodePaddingMode::RequireNone since it will decode
// a complete quad with padding in it before encountering the stray byte that makes it an invalid
// length
#[apply(all_engines_except_decoder_reader)]
fn decode_invalid_trailing_padding_as_invalid_length_all_modes<E: EngineWrapper>(
engine_wrapper: E,
) {
for mode in all_pad_modes() {
do_invalid_trailing_padding_as_invalid_length(E::standard_with_pad_mode(true, mode), mode);
}
}
#[apply(all_engines)]
fn decode_wrong_length_error<E: EngineWrapper>(engine_wrapper: E) {
let engine = E::standard_with_pad_mode(true, DecodePaddingMode::Indifferent);
for num_prefix_quads in 0..256 {
// at least one token, otherwise it wouldn't be a final quad
for num_tokens_final_quad in 1..=4 {
for num_padding in 0..=(4 - num_tokens_final_quad) {
let mut s: String = "IIII".repeat(num_prefix_quads);
for _ in 0..num_tokens_final_quad {
s.push('g');
}
for _ in 0..num_padding {
s.push('=');
}
let res = engine.decode(&s);
if num_tokens_final_quad >= 2 {
assert!(res.is_ok());
} else if num_tokens_final_quad == 1 && num_padding > 0 {
// = is invalid if it's too early
assert_eq!(
Err(DecodeError::InvalidByte(
num_prefix_quads * 4 + num_tokens_final_quad,
61
)),
res
);
} else if num_padding > 2 {
assert_eq!(Err(DecodeError::InvalidPadding), res);
} else {
assert_eq!(Err(DecodeError::InvalidLength), res);
}
}
}
}
}
#[apply(all_engines)]
fn decode_into_slice_fits_in_precisely_sized_slice<E: EngineWrapper>(engine_wrapper: E) {
let mut orig_data = Vec::new();
let mut encoded_data = String::new();
let mut decode_buf = Vec::new();
let input_len_range = distributions::Uniform::new(0, 1000);
let mut rng = rngs::SmallRng::from_entropy();
for _ in 0..10_000 {
orig_data.clear();
encoded_data.clear();
decode_buf.clear();
let input_len = input_len_range.sample(&mut rng);
for _ in 0..input_len {
orig_data.push(rng.gen());
}
let engine = E::random(&mut rng);
engine.encode_string(&orig_data, &mut encoded_data);
assert_encode_sanity(&encoded_data, engine.config().encode_padding(), input_len);
decode_buf.resize(input_len, 0);
// decode into the non-empty buf
let decode_bytes_written = engine
.decode_slice_unchecked(encoded_data.as_bytes(), &mut decode_buf[..])
.unwrap();
assert_eq!(orig_data.len(), decode_bytes_written);
assert_eq!(orig_data, decode_buf);
}
}
#[apply(all_engines)]
fn inner_decode_reports_padding_position<E: EngineWrapper>(engine_wrapper: E) {
let mut b64 = String::new();
let mut decoded = Vec::new();
let engine = E::standard();
for pad_position in 1..10_000 {
b64.clear();
decoded.clear();
// plenty of room for original data
decoded.resize(pad_position, 0);
for _ in 0..pad_position {
b64.push('A');
}
// finish the quad with padding
for _ in 0..(4 - (pad_position % 4)) {
b64.push('=');
}
let decode_res = engine.internal_decode(
b64.as_bytes(),
&mut decoded[..],
engine.internal_decoded_len_estimate(b64.len()),
);
if pad_position % 4 < 2 {
// impossible padding
assert_eq!(
Err(DecodeError::InvalidByte(pad_position, PAD_BYTE)),
decode_res
);
} else {
let decoded_bytes = pad_position / 4 * 3
+ match pad_position % 4 {
0 => 0,
2 => 1,
3 => 2,
_ => unreachable!(),
};
assert_eq!(
Ok(DecodeMetadata::new(decoded_bytes, Some(pad_position))),
decode_res
);
}
}
}
#[apply(all_engines)]
fn decode_length_estimate_delta<E: EngineWrapper>(engine_wrapper: E) {
for engine in [E::standard(), E::standard_unpadded()] {
for &padding in &[true, false] {
for orig_len in 0..1000 {
let encoded_len = encoded_len(orig_len, padding).unwrap();
let decoded_estimate = engine
.internal_decoded_len_estimate(encoded_len)
.decoded_len_estimate();
assert!(decoded_estimate >= orig_len);
assert!(
decoded_estimate - orig_len < 3,
"estimate: {}, encoded: {}, orig: {}",
decoded_estimate,
encoded_len,
orig_len
);
}
}
}
}
#[apply(all_engines)]
fn estimate_via_u128_inflation<E: EngineWrapper>(engine_wrapper: E) {
// cover both ends of usize
(0..1000)
.chain(usize::MAX - 1000..=usize::MAX)
.for_each(|encoded_len| {
// inflate to 128 bit type to be able to safely use the easy formulas
let len_128 = encoded_len as u128;
let estimate = E::standard()
.internal_decoded_len_estimate(encoded_len)
.decoded_len_estimate();
// This check is a little too strict: it requires using the (len + 3) / 4 * 3 formula
// or equivalent, but until other engines come along that use a different formula
// requiring that we think more carefully about what the allowable criteria are, this
// will do.
assert_eq!(
((len_128 + 3) / 4 * 3) as usize,
estimate,
"enc len {}",
encoded_len
);
})
}
fn do_invalid_trailing_byte(engine: impl Engine, mode: DecodePaddingMode) {
for num_prefix_quads in 0..256 {
let mut s: String = "ABCD".repeat(num_prefix_quads);
s.push_str("Cg==\n");
// The case of trailing newlines is common enough to warrant a test for a good error
// message.
assert_eq!(
Err(DecodeError::InvalidByte(num_prefix_quads * 4 + 4, b'\n')),
engine.decode(&s),
"mode: {:?}, input: {}",
mode,
s
);
}
}
fn do_invalid_trailing_padding_as_invalid_length(engine: impl Engine, mode: DecodePaddingMode) {
for num_prefix_quads in 0..256 {
let mut s: String = "ABCD".repeat(num_prefix_quads);
s.push_str("Cg===");
assert_eq!(
Err(DecodeError::InvalidLength),
engine.decode(&s),
"mode: {:?}, input: {}",
mode,
s
);
}
}
/// Returns a tuple of the original data length, the encoded data length (just data), and the length including padding.
///
/// Vecs provided should be empty.
fn generate_random_encoded_data<E: Engine, R: rand::Rng, D: distributions::Distribution<usize>>(
engine: &E,
orig_data: &mut Vec<u8>,
encode_buf: &mut Vec<u8>,
rng: &mut R,
length_distribution: &D,
) -> (usize, usize, usize) {
let padding: bool = engine.config().encode_padding();
let orig_len = fill_rand(orig_data, rng, length_distribution);
let expected_encoded_len = encoded_len(orig_len, padding).unwrap();
encode_buf.resize(expected_encoded_len, 0);
let base_encoded_len = engine.internal_encode(&orig_data[..], &mut encode_buf[..]);
let enc_len_with_padding = if padding {
base_encoded_len + add_padding(base_encoded_len, &mut encode_buf[base_encoded_len..])
} else {
base_encoded_len
};
assert_eq!(expected_encoded_len, enc_len_with_padding);
(orig_len, base_encoded_len, enc_len_with_padding)
}
// fill to a random length
fn fill_rand<R: rand::Rng, D: distributions::Distribution<usize>>(
vec: &mut Vec<u8>,
rng: &mut R,
length_distribution: &D,
) -> usize {
let len = length_distribution.sample(rng);
for _ in 0..len {
vec.push(rng.gen());
}
len
}
fn fill_rand_len<R: rand::Rng>(vec: &mut Vec<u8>, rng: &mut R, len: usize) {
for _ in 0..len {
vec.push(rng.gen());
}
}
fn prefixed_data<'i>(input_with_prefix: &'i mut String, prefix_len: usize, data: &str) -> &'i str {
input_with_prefix.truncate(prefix_len);
input_with_prefix.push_str(data);
input_with_prefix.as_str()
}
/// A wrapper to make using engines in rstest fixtures easier.
/// The functions don't need to be instance methods, but rstest does seem
/// to want an instance, so instances are passed to test functions and then ignored.
trait EngineWrapper {
type Engine: Engine;
/// Return an engine configured for RFC standard base64
fn standard() -> Self::Engine;
/// Return an engine configured for RFC standard base64, except with no padding appended on
/// encode, and required no padding on decode.
fn standard_unpadded() -> Self::Engine;
/// Return an engine configured for RFC standard alphabet with the provided encode and decode
/// pad settings
fn standard_with_pad_mode(encode_pad: bool, decode_pad_mode: DecodePaddingMode)
-> Self::Engine;
/// Return an engine configured for RFC standard base64 that allows invalid trailing bits
fn standard_allow_trailing_bits() -> Self::Engine;
/// Return an engine configured with a randomized alphabet and config
fn random<R: rand::Rng>(rng: &mut R) -> Self::Engine;
/// Return an engine configured with the specified alphabet and randomized config
fn random_alphabet<R: rand::Rng>(rng: &mut R, alphabet: &Alphabet) -> Self::Engine;
}
struct GeneralPurposeWrapper {}
impl EngineWrapper for GeneralPurposeWrapper {
type Engine = general_purpose::GeneralPurpose;
fn standard() -> Self::Engine {
general_purpose::GeneralPurpose::new(&STANDARD, general_purpose::PAD)
}
fn standard_unpadded() -> Self::Engine {
general_purpose::GeneralPurpose::new(&STANDARD, general_purpose::NO_PAD)
}
fn standard_with_pad_mode(
encode_pad: bool,
decode_pad_mode: DecodePaddingMode,
) -> Self::Engine {
general_purpose::GeneralPurpose::new(
&STANDARD,
general_purpose::GeneralPurposeConfig::new()
.with_encode_padding(encode_pad)
.with_decode_padding_mode(decode_pad_mode),
)
}
fn standard_allow_trailing_bits() -> Self::Engine {
general_purpose::GeneralPurpose::new(
&STANDARD,
general_purpose::GeneralPurposeConfig::new().with_decode_allow_trailing_bits(true),
)
}
fn random<R: rand::Rng>(rng: &mut R) -> Self::Engine {
let alphabet = random_alphabet(rng);
Self::random_alphabet(rng, alphabet)
}
fn random_alphabet<R: rand::Rng>(rng: &mut R, alphabet: &Alphabet) -> Self::Engine {
general_purpose::GeneralPurpose::new(alphabet, random_config(rng))
}
}
struct NaiveWrapper {}
impl EngineWrapper for NaiveWrapper {
type Engine = naive::Naive;
fn standard() -> Self::Engine {
naive::Naive::new(
&STANDARD,
naive::NaiveConfig {
encode_padding: true,
decode_allow_trailing_bits: false,
decode_padding_mode: DecodePaddingMode::RequireCanonical,
},
)
}
fn standard_unpadded() -> Self::Engine {
naive::Naive::new(
&STANDARD,
naive::NaiveConfig {
encode_padding: false,
decode_allow_trailing_bits: false,
decode_padding_mode: DecodePaddingMode::RequireNone,
},
)
}
fn standard_with_pad_mode(
encode_pad: bool,
decode_pad_mode: DecodePaddingMode,
) -> Self::Engine {
naive::Naive::new(
&STANDARD,
naive::NaiveConfig {
encode_padding: false,
decode_allow_trailing_bits: false,
decode_padding_mode: decode_pad_mode,
},
)
}
fn standard_allow_trailing_bits() -> Self::Engine {
naive::Naive::new(
&STANDARD,
naive::NaiveConfig {
encode_padding: true,
decode_allow_trailing_bits: true,
decode_padding_mode: DecodePaddingMode::RequireCanonical,
},
)
}
fn random<R: rand::Rng>(rng: &mut R) -> Self::Engine {
let alphabet = random_alphabet(rng);
Self::random_alphabet(rng, alphabet)
}
fn random_alphabet<R: rand::Rng>(rng: &mut R, alphabet: &Alphabet) -> Self::Engine {
let mode = rng.gen();
let config = naive::NaiveConfig {
encode_padding: match mode {
DecodePaddingMode::Indifferent => rng.gen(),
DecodePaddingMode::RequireCanonical => true,
DecodePaddingMode::RequireNone => false,
},
decode_allow_trailing_bits: rng.gen(),
decode_padding_mode: mode,
};
naive::Naive::new(alphabet, config)
}
}
/// A pseudo-Engine that routes all decoding through [DecoderReader]
struct DecoderReaderEngine<E: Engine> {
engine: E,
}
impl<E: Engine> From<E> for DecoderReaderEngine<E> {
fn from(value: E) -> Self {
Self { engine: value }
}
}
impl<E: Engine> Engine for DecoderReaderEngine<E> {
type Config = E::Config;
type DecodeEstimate = E::DecodeEstimate;
fn internal_encode(&self, input: &[u8], output: &mut [u8]) -> usize {
self.engine.internal_encode(input, output)
}
fn internal_decoded_len_estimate(&self, input_len: usize) -> Self::DecodeEstimate {
self.engine.internal_decoded_len_estimate(input_len)
}
fn internal_decode(
&self,
input: &[u8],
output: &mut [u8],
decode_estimate: Self::DecodeEstimate,
) -> Result<DecodeMetadata, DecodeError> {
let mut reader = DecoderReader::new(input, &self.engine);
let mut buf = vec![0; input.len()];
// to avoid effects like not detecting invalid length due to progressively growing
// the output buffer in read_to_end etc, read into a big enough buffer in one go
// to make behavior more consistent with normal engines
let _ = reader
.read(&mut buf)
.and_then(|len| {
buf.truncate(len);
// make sure we got everything
reader.read_to_end(&mut buf)
})
.map_err(|io_error| {
*io_error
.into_inner()
.and_then(|inner| inner.downcast::<DecodeError>().ok())
.unwrap()
})?;
output[..buf.len()].copy_from_slice(&buf);
Ok(DecodeMetadata::new(
buf.len(),
input
.iter()
.enumerate()
.filter(|(_offset, byte)| **byte == PAD_BYTE)
.map(|(offset, _byte)| offset)
.next(),
))
}
fn config(&self) -> &Self::Config {
self.engine.config()
}
}
struct DecoderReaderEngineWrapper {}
impl EngineWrapper for DecoderReaderEngineWrapper {
type Engine = DecoderReaderEngine<general_purpose::GeneralPurpose>;
fn standard() -> Self::Engine {
GeneralPurposeWrapper::standard().into()
}
fn standard_unpadded() -> Self::Engine {
GeneralPurposeWrapper::standard_unpadded().into()
}
fn standard_with_pad_mode(
encode_pad: bool,
decode_pad_mode: DecodePaddingMode,
) -> Self::Engine {
GeneralPurposeWrapper::standard_with_pad_mode(encode_pad, decode_pad_mode).into()
}
fn standard_allow_trailing_bits() -> Self::Engine {
GeneralPurposeWrapper::standard_allow_trailing_bits().into()
}
fn random<R: rand::Rng>(rng: &mut R) -> Self::Engine {
GeneralPurposeWrapper::random(rng).into()
}
fn random_alphabet<R: rand::Rng>(rng: &mut R, alphabet: &Alphabet) -> Self::Engine {
GeneralPurposeWrapper::random_alphabet(rng, alphabet).into()
}
}
fn seeded_rng() -> impl rand::Rng {
rngs::SmallRng::from_entropy()
}
fn all_pad_modes() -> Vec<DecodePaddingMode> {
vec![
DecodePaddingMode::Indifferent,
DecodePaddingMode::RequireCanonical,
DecodePaddingMode::RequireNone,
]
}
fn pad_modes_allowing_padding() -> Vec<DecodePaddingMode> {
vec![
DecodePaddingMode::Indifferent,
DecodePaddingMode::RequireCanonical,
]
}
fn assert_all_suffixes_ok<E: Engine>(engine: E, suffixes: Vec<&str>) {
for num_prefix_quads in 0..256 {
for &suffix in suffixes.iter() {
let mut encoded = "AAAA".repeat(num_prefix_quads);
encoded.push_str(suffix);
let res = &engine.decode(&encoded);
assert!(res.is_ok());
}
}
}