def Encode(self, entropy_bytes: bytes) -> Mnemonic:
"""
Encode bytes to mnemonic phrase.
Args:
entropy_bytes (bytes): Entropy bytes (accepted lengths in bits: 128, 160, 192, 224, 256)
Returns:
Mnemonic object: Encoded mnemonic
Raises:
ValueError: If entropy is not valid
"""
# Check entropy length
entropy_byte_len = len(entropy_bytes)
if not Bip39EntropyGenerator.IsValidEntropyByteLen(entropy_byte_len):
raise ValueError(
f"Entropy byte length ({entropy_byte_len}) is not valid")
# Convert entropy to binary string
entropy_bin_str = BytesUtils.ToBinaryStr(entropy_bytes,
entropy_byte_len * 8)
# Get entropy hash as binary string
entropy_hash_bin_str = BytesUtils.ToBinaryStr(
CryptoUtils.Sha256(entropy_bytes),
CryptoUtils.Sha256DigestSize() * 8)
# Get mnemonic binary string by concatenating entropy and checksum
mnemonic_bin_str = entropy_bin_str + entropy_hash_bin_str[:entropy_byte_len
// 4]
# Get mnemonic from entropy
mnemonic = []
for i in range(
len(mnemonic_bin_str) // Bip39MnemonicConst.WORD_BIT_LEN):
# Get current word index
word_bin_str = (
mnemonic_bin_str[i * Bip39MnemonicConst.WORD_BIT_LEN:(i + 1) *
Bip39MnemonicConst.WORD_BIT_LEN])
word_idx = IntegerUtils.FromBinaryStr(word_bin_str)
# Get word at given index
mnemonic.append(self.m_words_list.GetWordAtIdx(word_idx))
return Bip39Mnemonic.FromList(mnemonic)
def __ComputeChecksumBinaryStr(self, mnemonic_bin_str: str) -> str:
"""
Compute checksum from mnemonic binary string.
Args:
mnemonic_bin_str (str): Mnemonic binary string
Returns:
str: Computed checksum binary string
"""
# Get entropy bytes
entropy_bytes = self.__EntropyBytesFromBinaryStr(mnemonic_bin_str)
# Convert entropy hash to binary string
entropy_hash_bin_str = BytesUtils.ToBinaryStr(
CryptoUtils.Sha256(entropy_bytes),
CryptoUtils.Sha256DigestSize() * 8)
# Return checksum
return entropy_hash_bin_str[:self.__GetChecksumLen(mnemonic_bin_str)]
