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 }