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use std::str;
use rand::{
distributions,
distributions::{Distribution as _, Uniform},
seq::SliceRandom,
Rng, SeedableRng,
};
use crate::{
alphabet,
encode::encoded_len,
engine::{
general_purpose::{GeneralPurpose, GeneralPurposeConfig},
Config, DecodePaddingMode, Engine,
},
};
#[test]
fn roundtrip_random_config_short() {
// exercise the slower encode/decode routines that operate on shorter buffers more vigorously
roundtrip_random_config(Uniform::new(0, 50), 10_000);
}
#[test]
fn roundtrip_random_config_long() {
roundtrip_random_config(Uniform::new(0, 1000), 10_000);
}
pub fn assert_encode_sanity(encoded: &str, padded: bool, input_len: usize) {
let input_rem = input_len % 3;
let expected_padding_len = if input_rem > 0 {
if padded {
3 - input_rem
} else {
0
}
} else {
0
};
let expected_encoded_len = encoded_len(input_len, padded).unwrap();
assert_eq!(expected_encoded_len, encoded.len());
let padding_len = encoded.chars().filter(|&c| c == '=').count();
assert_eq!(expected_padding_len, padding_len);
let _ = str::from_utf8(encoded.as_bytes()).expect("Base64 should be valid utf8");
}
fn roundtrip_random_config(input_len_range: Uniform<usize>, iterations: u32) {
let mut input_buf: Vec<u8> = Vec::new();
let mut encoded_buf = String::new();
let mut rng = rand::rngs::SmallRng::from_entropy();
for _ in 0..iterations {
input_buf.clear();
encoded_buf.clear();
let input_len = input_len_range.sample(&mut rng);
let engine = random_engine(&mut rng);
for _ in 0..input_len {
input_buf.push(rng.gen());
}
engine.encode_string(&input_buf, &mut encoded_buf);
assert_encode_sanity(&encoded_buf, engine.config().encode_padding(), input_len);
assert_eq!(input_buf, engine.decode(&encoded_buf).unwrap());
}
}
pub fn random_config<R: Rng>(rng: &mut R) -> GeneralPurposeConfig {
let mode = rng.gen();
GeneralPurposeConfig::new()
.with_encode_padding(match mode {
DecodePaddingMode::Indifferent => rng.gen(),
DecodePaddingMode::RequireCanonical => true,
DecodePaddingMode::RequireNone => false,
})
.with_decode_padding_mode(mode)
.with_decode_allow_trailing_bits(rng.gen())
}
impl distributions::Distribution<DecodePaddingMode> for distributions::Standard {
fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> DecodePaddingMode {
match rng.gen_range(0..=2) {
0 => DecodePaddingMode::Indifferent,
1 => DecodePaddingMode::RequireCanonical,
_ => DecodePaddingMode::RequireNone,
}
}
}
pub fn random_alphabet<R: Rng>(rng: &mut R) -> &'static alphabet::Alphabet {
ALPHABETS.choose(rng).unwrap()
}
pub fn random_engine<R: Rng>(rng: &mut R) -> GeneralPurpose {
let alphabet = random_alphabet(rng);
let config = random_config(rng);
GeneralPurpose::new(alphabet, config)
}
const ALPHABETS: &[alphabet::Alphabet] = &[
alphabet::URL_SAFE,
alphabet::STANDARD,
alphabet::CRYPT,
alphabet::BCRYPT,
alphabet::IMAP_MUTF7,
alphabet::BIN_HEX,
];