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rust-bip39-unsafe-fast
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Clarify some constants in from_entropy_in

This commit is contained in:
Steven Roose 2021-03-06 18:02:32 +00:00
parent 14495917ca
commit e44e4b27d8
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2 changed files with 17 additions and 12 deletions
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27
src/lib.rs
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@ -143,28 +143,33 @@ impl Mnemonic {
/// Create a new [Mnemonic] in the specified language from the given entropy.
/// Entropy must be a multiple of 32 bits (4 bytes) and 128-256 bits in length.
pub fn from_entropy_in(language: Language, entropy: &[u8]) -> Result<Mnemonic, Error> {
if entropy.len() % 4 != 0 {
return Err(Error::BadEntropyBitCount(entropy.len() * 8));
}
const MAX_ENTROPY_BITS: usize = 256;
const MIN_ENTROPY_BITS: usize = 128;
const MAX_CHECKSUM_BITS: usize = 8;
if (entropy.len() * 8) < 128 || (entropy.len() * 8) > 256 {
return Err(Error::BadEntropyBitCount(entropy.len() * 8));
let nb_bytes = entropy.len();
let nb_bits = nb_bytes * 8;
if nb_bits % 32 != 0 {
return Err(Error::BadEntropyBitCount(nb_bits));
}
if nb_bits < MIN_ENTROPY_BITS || nb_bits > MAX_ENTROPY_BITS {
return Err(Error::BadEntropyBitCount(nb_bits));
}
const MAX_ENTROPY_LEN: usize = 32;
let check = sha256::Hash::hash(&entropy);
let mut bits = [false; MAX_ENTROPY_LEN * 8 + MAX_ENTROPY_LEN / 4];
for i in 0..entropy.len() {
let mut bits = [false; MAX_ENTROPY_BITS + MAX_CHECKSUM_BITS];
for i in 0..nb_bytes {
for j in 0..8 {
bits[i * 8 + j] = (entropy[i] & (1 << (7 - j))) > 0;
}
}
for i in 0..entropy.len() / 4 {
bits[8 * entropy.len() + i] = (check[i / 8] & (1 << (7 - (i % 8)))) > 0;
for i in 0..nb_bytes / 4 {
bits[8 * nb_bytes + i] = (check[i / 8] & (1 << (7 - (i % 8)))) > 0;
}
let mut words: [&'static str; MAX_NB_WORDS] = Default::default();
let nb_words = entropy.len() * 3 / 4;
let nb_words = nb_bytes * 3 / 4;
for i in 0..nb_words {
let mut idx = 0;
for j in 0..11 {