以太坊系列（二）之账户管理
1. 账户
以太坊有两种账户类型：
- 外部账户（EOA）
- 合约账户
所有账户的状态代表以太坊网络的状态，以太坊网络会和每一个区块一起更新，网络需要达成关于以太坊的共识。账户代表外部代理人的身份，账户运用非对称加密的私钥来签署交易，以便以太坊虚拟机可以安全验证交易发送者的身份。
2. 钥匙文件(Keyfiles)
每个账户都由一对密钥来定义，包括公钥和私钥。账户以地址为索引，地址由公钥生成，每对私钥/地址都编码在一个钥匙文件（JSON文件）中，其中最重要的为账户私钥，通常用创建账户时的密码加密。可以在以太坊节点数据目录的keystore子目录下找到钥匙文件。
3. 创建账户
为了从账户发送交易包括以太币，需要拥有Keyfiles和密码。需要记住并备份钥匙文件，没有“找回密码”的选项。
3.1. 使用geth account new
geth是以太坊的go语言客户端。创建账户只需要执行geth account new命令。
3.1.1. 下载安装
# 下载源码
git clone https://github.com/ethereum/go-ethereum.git
# 编译
cd go-ethereum
make geth
# 编译后会在`go-ethereum/build/bin/`目录下生成二进制文件，拷贝到$PATH路径下
cp build/bin/geth /usr/local/bin/
# 验证
geth --help
go的版本最好在
1.9.2及以上版本，否则编译可能报以下错误... # github.com/ethereum/go-ethereum/vendor/gopkg.in/olebedev/go-duktape.v3 vendor/gopkg.in/olebedev/go-duktape.v3/duktape.go:133: constant 18446744073709551615 overflows int64 util.go:45: exit status 2 exit status 1 make: *** [all] Error 1
3.1.2. 创建账户
geth account new
# 交互式，输入密码
$ geth account new
INFO [07-09|05:06:46.393] Maximum peer count ETH=25 LES=0 total=25
Your new account is locked with a password. Please give a password. Do not forget this password.
Passphrase:
Repeat passphrase:
Address: {df90109c1497bc6f3a0cd98cdc114ec89481447e}
# 非交互式，从文件读取密码。不建议使用，容易暴露密码
$ geth --password /path/to/password account new
# 例如
$ geth --password ethpasswd account new
INFO [07-09|05:27:48.567] Maximum peer count ETH=25 LES=0 total=25
Address: {0ad31ccaf888cf8499de4cdfa18f8d746a1d27e7}
3.1.3. 查询账户
geth account list
$ geth account list
INFO [07-09|05:29:31.708] Maximum peer count ETH=25 LES=0 total=25
Account #0: {df90109c1497bc6f3a0cd98cdc114ec89481447e} keystore:///root/.ethereum/keystore/UTC--2018-07-08T21-07-05.374654217Z--df90109c1497bc6f3a0cd98cdc114ec89481447e
Account #1: {0ad31ccaf888cf8499de4cdfa18f8d746a1d27e7} keystore:///root/.ethereum/keystore/UTC--2018-07-08T21-27-48.567366972Z--0ad31ccaf888cf8499de4cdfa18f8d746a1d27e7
keyfiles存储在~/.ethereum/keystore路径下，一般按照创建时间顺序排列，格式如下：
$ cd .ethereum/keystore
$ ls
UTC--2018-07-08T21-07-05.374654217Z--df90109c1497bc6f3a0cd98cdc114ec89481447e
UTC--2018-07-08T21-27-48.567366972Z--0ad31ccaf888cf8499de4cdfa18f8d746a1d27e7
keyfile的文件内容如下：
$ cat UTC--2018-07-08T21-07-05.374654217Z--df90109c1497bc6f3a0cd98cdc114ec89481447e | python -m json.tool
{
"address": "df90109c1497bc6f3a0cd98cdc114ec89481447e",
"crypto": {
"cipher": "aes-128-ctr",
"cipherparams": {
"iv": "ac945759e1e445776387eeb855df208d"
},
"ciphertext": "4c75c2dcbba248e9f0f43bb4fed4ca9be10b00c02bb60ad7926f013541266592",
"kdf": "scrypt",
"kdfparams": {
"dklen": 32,
"n": 262144,
"p": 1,
"r": 8,
"salt": "199c4c1129a594871e47f3be3b71d57b8e0efcd5f543b9684495f007eb51ce1c"
},
"mac": "da461ede939be6509db7bf25f0b30b557d66e5edc26b9590dfbba733e4af5c7b"
},
"id": "7cda7e39-1132-4b0c-aade-2aed1e845ed1",
"version": 3
}
3.2. 使用geth控制台
使用geth控制台创建新账户，需要在控制台模式下开启geth交互模式。
$ geth console 2>> file_to_log_output
Welcome to the Geth JavaScript console!
instance: Geth/v1.8.13-unstable-3b074515/linux-amd64/go1.9.4
coinbase: 0xdf90109c1497bc6f3a0cd98cdc114ec89481447e
at block: 0 (Thu, 01 Jan 1970 08:00:00 CST)
datadir: /root/.ethereum
modules: admin:1.0 debug:1.0 eth:1.0 miner:1.0 net:1.0 personal:1.0 rpc:1.0 txpool:1.0 web3:1.0
>
3.2.1. 创建账户
personal.newAccount()
> personal.newAccount()
Passphrase:
Repeat passphrase:
"0x06341612bc695a2cab1d294630ce44f8789efabc"
3.2.2. 列出账户
eth.accounts
> eth.accounts
["0xdf90109c1497bc6f3a0cd98cdc114ec89481447e", "0x0ad31ccaf888cf8499de4cdfa18f8d746a1d27e7", "0x06341612bc695a2cab1d294630ce44f8789efabc"]
4. 更新、备份、恢复账户
4.1. 更新账户
geth account update更改账户密码，需要输入原密码。
以下通过账户地址来修改密码：
$ geth account update df90109c1497bc6f3a0cd98cdc114ec89481447e
INFO [07-09|06:02:53.411] Maximum peer count ETH=25 LES=0 total=25
Unlocking account df90109c1497bc6f3a0cd98cdc114ec89481447e | Attempt 1/3
Passphrase:
INFO [07-09|06:02:57.475] Unlocked account address=0xdF90109c1497bc6f3a0cd98cdC114Ec89481447E
Please give a new password. Do not forget this password.
Passphrase:
Repeat passphrase:
也可以通过账户索引来修改密码：
# 以下示例的账号索引为 0
$ geth account update 0
INFO [07-09|06:05:59.087] Maximum peer count ETH=25 LES=0 total=25
WARN [07-09|06:05:59.087] -------------------------------------------------------------------
WARN [07-09|06:05:59.087] Referring to accounts by order in the keystore folder is dangerous!
WARN [07-09|06:05:59.087] This functionality is deprecated and will be removed in the future!
WARN [07-09|06:05:59.087] Please use explicit addresses! (can search via `geth account list`)
WARN [07-09|06:05:59.087] -------------------------------------------------------------------
Unlocking account 0 | Attempt 1/3
Passphrase:
INFO [07-09|06:06:04.081] Unlocked account address=0xdF90109c1497bc6f3a0cd98cdC114Ec89481447E
Please give a new password. Do not forget this password.
Passphrase:
Repeat passphrase:
可以通过--password参数修改，仍需要输入文件中的密码：
geth --password ethpasswd account update 0ad31ccaf888cf8499de4cdfa18f8d746a1d27e7
INFO [07-09|06:10:16.564] Maximum peer count ETH=25 LES=0 total=25
Unlocking account 0ad31ccaf888cf8499de4cdfa18f8d746a1d27e7 | Attempt 1/3
Passphrase:
INFO [07-09|06:11:04.954] Unlocked account address=0x0AD31CcAf888Cf8499de4cdFA18F8d746A1d27E7
Please give a new password. Do not forget this password.
Passphrase:
Repeat passphrase:
4.2. 账户备份和恢复
手动备份/恢复
要从账户发送交易需要keyfile，Linux系统中，keyfile位于~/.ethereum/keystore中。
- 备份keyfile：复制keystore目录下的一个或多个keyfile。
- 恢复keyfile：将备份的keyfile重新拷贝到keystore的目录下。
导入未加密的私钥
geth account import /path/to/<keyfile>
参考：