void pbkdf2_hmac_sha512(const uint8_t *pass, int passlen, const uint8_t *salt, int saltlen, uint32_t iterations, uint8_t *key)
{
PBKDF2_HMAC_SHA512_CTX pctx;
pbkdf2_hmac_sha512_Init(&pctx, pass, passlen, salt, saltlen);
pbkdf2_hmac_sha512_Update(&pctx, iterations);
pbkdf2_hmac_sha512_Final(&pctx, key);
}
// passphrase must be at most 256 characters or code may crash
void mnemonic_to_seed(const char *mnemonic, const char *passphrase, uint8_t seed[512 / 8], void (*progress_callback)(uint32_t current, uint32_t total))
{
int passphraselen = strlen(passphrase);
#if USE_BIP39_CACHE
int mnemoniclen = strlen(mnemonic);
// check cache
if (mnemoniclen < 256 && passphraselen < 64) {
for (int i = 0; i < BIP39_CACHE_SIZE; i++) {
if (!bip39_cache[i].set) continue;
if (strcmp(bip39_cache[i].mnemonic, mnemonic) != 0) continue;
if (strcmp(bip39_cache[i].passphrase, passphrase) != 0) continue;
// found the correct entry
memcpy(seed, bip39_cache[i].seed, 512 / 8);
return;
}
}
#endif
uint8_t salt[8 + 256];
memcpy(salt, "mnemonic", 8);
memcpy(salt + 8, passphrase, passphraselen);
PBKDF2_HMAC_SHA512_CTX pctx;
pbkdf2_hmac_sha512_Init(&pctx, (const uint8_t *)mnemonic, strlen(mnemonic), salt, passphraselen + 8);
if (progress_callback) {
progress_callback(0, BIP39_PBKDF2_ROUNDS);
}
for (int i = 0; i < 8; i++) {
pbkdf2_hmac_sha512_Update(&pctx, BIP39_PBKDF2_ROUNDS / 8);
if (progress_callback) {
progress_callback((i + 1) * BIP39_PBKDF2_ROUNDS / 8, BIP39_PBKDF2_ROUNDS);
}
}
pbkdf2_hmac_sha512_Final(&pctx, seed);
#if USE_BIP39_CACHE
// store to cache
if (mnemoniclen < 256 && passphraselen < 64) {
bip39_cache[bip39_cache_index].set = true;
strcpy(bip39_cache[bip39_cache_index].mnemonic, mnemonic);
strcpy(bip39_cache[bip39_cache_index].passphrase, passphrase);
memcpy(bip39_cache[bip39_cache_index].seed, seed, 512 / 8);
bip39_cache_index = (bip39_cache_index + 1) % BIP39_CACHE_SIZE;
}
#endif
}