在日常生活中，大家都会买个钱包用于存放我们日常使用发行的纸币，那数字资产世界的钱包是怎么样的呢？ 对于数字资产世界里而言，钱包就是一个密钥 (包含私钥和公钥) 的管理容器。用户用私钥来签名交易, 从而证明该用户拥有交易的输出权限，其交易信息并不是存储在该钱包内，而是储存在区块链中。
区块链数字钱包系统能对比特币、以太坊等多种主流的数字货币进行统一的管理与存储，也就是说所有货币都能装到一个钱包来进行管理，这样大大的降低了数字货币的使用门槛和管理负担，使用起来也更加灵活方便。 一个钱包通常主要包含的功能有： 账号管理（主要是私钥的管理）：创建账号、账号导入导出 账号信息展示：如以太币余额、Token（代币）余额。 转账功能：发送以太币及发送Token（代币）
区块链钱包开发源码示例：
钱包文件
保存私钥和转账记录
Wallet containing 0.01 BTC (spendable: 0.01 BTC) in:
0 pending transactions
1 unspent transactions
0 spent transactions
0 dead transactionsLast seen best block: 1384907 (2018-08-22T03:38:42Z): 0000000000000030fe01a48a7cd6b0c52909a7d019084d195ae3ebd2889c82ec
Keys:Earliest creation time: 2018-08-20T07:51:29ZSeed birthday: 1534751489 [2018-08-20T07:51:29Z]Key to watch: tpubD92y4mcSrbcSxANfCgiWx7h7sGquSF4ogNPcUxC2GECSwgWBMNPMo2C8nxez2ngvSS4UfaGhSunemWoqZ6aAAzLb4WLsmQxDirfFgE9tG5J
addr:mq5gdvJDuDEmNKFPbgMn8pGm3pyJvkSsHv hash160:68e9c9e06890527cd0f0b59d83333502ac127bef (M/0H/0/0)
>>> UNSPENT:0.01 BTC total value (sends 0.00 BTC and receives 0.01 BTC)
confidence: Seen by 7 peers (most recently: 2018-08-22T03:33:33Z). Appeared in best chain at height 1384907, depth 1. Source: NETWORK
a82c35c2133bd357bfa462f82d75b28787afcdcd20c8b89cd2b78f48138d6e9f
updated: 2018-08-22T03:31:53Z
in PUSHDATA(71)[304402205d3e0974b4604b92e09f83950b183100bd47243c9cb548f2213a9ca26e83bdd3022018278c7ce9b65982e6c67ba9acf8e6e3898f1dad80702bb1e32c4a0b61195e0f01] PUSHDATA(33)[02f8769ecddd821cc9b75c554978b4a674df28c098e640fd0188b88bf019bc31fa]
outpoint:8294b8dcf6513ab13321d4dd1642bf1c19600a313bf1ebe8511521dcd4dd0277:0
out DUP HASH160 PUSHDATA(20)[8843beff2291c5a00aa00fbd8a541f800c83b86d] EQUALVERIFY CHECKSIG 1.1899548 BTC
out DUP HASH160 PUSHDATA(20)[68e9c9e06890527cd0f0b59d83333502ac127bef] EQUALVERIFY CHECKSIG 0.01 BTC
prps UNKNOWN
## ##
获取钱包地址
//Utils.java
public static byte[] sha256hash160(byte[] input) {
byte[] sha256 = Sha256Hash.hash(input);
RIPEMD160Digest digest = new RIPEMD160Digest();
digest.update(sha256, 0, sha256.length);
byte[] out = new byte[20];
digest.doFinal(out, 0);
return out;
}
从文件中加载钱包
//
读取钱包文件
File walletFile = activity.getFileStreamPath("wallet-protobuf");
if (walletFile.exists()) {
InputStream inputStream = new FileInputStream(walletFile);
//
反序列化
wallet = new WalletProtobufSerializer().readWallet(inputStream);
//
设置自动保存
wallet.autosaveToFile(walletFile, 3 * 1000, TimeUnit.MILLISECONDS, null);
//
清理钱包
wallet.cleanup();
}
通过助记词创建钱包
File destination = new File(walletDir, walletFileName);
objectMapper.writeValue(destination, wallet);
//
创建助记词
public List createMnemonics() throws MnemonicException.MnemonicLengthException {
SecureRandom secureRandom = new SecureRandom();
byte[] entropy = new byte[DeterministicSeed.DEFAULT_SEED_ENTROPY_BITS / 8];
secureRandom.nextBytes(entropy);
return MnemonicCode.INSTANCE.toMnemonic(entropy);
}
//m / 44' / 60' / 0' / 0
//Hardened
意思就是派生加固，防止获取到一个子私钥之后可以派生出后面的子私钥
//
必须还有上一级的父私钥才能派生
public static final ImmutableList BIP44_ETH_ACCOUNT_ZERO_PATH =
ImmutableList.of(new ChildNumber(44, true), new ChildNumber(60, true),
ChildNumber.ZERO_HARDENED, ChildNumber.ZERO);
//
通过助记词生成
HD
钱包
public void onCreateWallet(View view) {
byte[] seed = MnemonicCode.toSeed(words, "");
DeterministicKey masterPrivateKey = HDKeyDerivation.createMasterPrivateKey(seed);
DeterministicHierarchy deterministicHierarchy = new DeterministicHierarchy(masterPrivateKey);
// m / 44' / 60' / 0' / 0 / 0
DeterministicKey deterministicKey = deterministicHierarchy
.deriveChild(BIP44_ETH_ACCOUNT_ZERO_PATH, false, true, new ChildNumber(0));
byte[] bytes = deterministicKey.getPrivKeyBytes();
ECKeyPair keyPair = ECKeyPair.create(bytes);
try {
WalletFile walletFile = Wallet.createLight(PASSWORD, keyPair);
String address = walletFile.getAddress();
mAddress.setText("0x" + address);
} catch (CipherException e) {
e.printStackTrace();
}
}
