比特幣交易構成(二)
交易的構造、簽名與廣播
上篇介紹了交易結構、簽名等,為了更直觀的認識比特幣,藉助bitcoind演示手動構造並廣播交易的完整過程。
普通交易
1. 找出未花費的幣(unspent output)
通過命令:listunspent [minconf=1] [maxconf=9999999] ["address",...]
列出某個地址未花費的幣(交易),minconf
/maxconf
表示該筆收入交易的確認數範圍,如果需要列出還未確認的交易,需將minconf
設定為0。
執行:
1 |
bitcoind listunspent 0 100 '["1Lab618UuWjLmVA1Q64tHZXcLoc4397ZX3"]' |
輸出:
1 2 3 4 5 6 7 8 9 10 11 |
[ { "txid" : "296ea7bf981b44999d689853d17fe0ceb852a8a34e68fcd19f0a41e589132156", "vout" : 0, "address" : "1Lab618UuWjLmVA1Q64tHZXcLoc4397ZX3", "account" : "", "scriptPubKey" : "76a914d6c492056f3f99692b56967a42b8ad44ce76b67a88ac", "amount" : 0.19900000, "confirmations" : 1 } ] |
2. 建立待發送交易
建立待發送交易,由命令:createrawtransaction [{"txid":txid,"vout":n},...] {address:amount,...}
來完成。我們將 0.1BTC傳送至 1Q8s4qDRbCbFypG5AFNR9tFC57PStkPX1x ,並支付 0.0001 BTC做為礦工費。輸入交易的額度為 0.199 ,輸出為 0.1 + 0.0001 = 0.1001 ,那麼還剩餘: 0.199 - 0.1001 = 0.0989 ,將此作為找零發回給自己。
執行:
1 2 3 |
bitcoind createrawtransaction \ '[{"txid":"296ea7bf981b44999d689853d17fe0ceb852a8a34e68fcd19f0a41e589132156","vout":0}]' \ '{"1Q8s4qDRbCbFypG5AFNR9tFC57PStkPX1x":0.1, "1Lab618UuWjLmVA1Q64tHZXcLoc4397ZX3":0.0989}' |
輸出:
1 |
010000000156211389e5410a9fd1fc684ea3a852b8cee07fd15398689d99441b98bfa76e290000000000ffffffff0280969800000000001976a914fdc7990956642433ea75cabdcc0a9447c5d2b4ee88acd0e89600000000001976a914d6c492056f3f99692b56967a42b8ad44ce76b67a88ac00000000 |
通過命令:decoderawtransaction <hex string>
,可以將此段十六進位制字串解碼。
執行:
1 |
bitcoind decoderawtransaction '010000000156211389e5410a9fd1fc684ea3a852b8cee07fd15398689d99441b98bfa76e290000000000ffffffff0280969800000000001976a914fdc7990956642433ea75cabdcc0a9447c5d2b4ee88acd0e89600000000001976a914d6c492056f3f99692b56967a42b8ad44ce76b67a88ac00000000' |
輸出:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 |
{ "txid" : "54f773a3fdf7cb3292fc76b46c97e536348b3a0715886dbfd2f60e115fb3a8f0", "version" : 1, "locktime" : 0, "vin" : [ { "txid" : "296ea7bf981b44999d689853d17fe0ceb852a8a34e68fcd19f0a41e589132156", "vout" : 0, "scriptSig" : { "asm" : "", "hex" : "" }, "sequence" : 4294967295 } ], "vout" : [ { "value" : 0.10000000, "n" : 0, "scriptPubKey" : { "asm" : "OP_DUP OP_HASH160 fdc7990956642433ea75cabdcc0a9447c5d2b4ee OP_EQUALVERIFY OP_CHECKSIG", "hex" : "76a914fdc7990956642433ea75cabdcc0a9447c5d2b4ee88ac", "reqSigs" : 1, "type" : "pubkeyhash", "addresses" : [ "1Q8s4qDRbCbFypG5AFNR9tFC57PStkPX1x" ] } }, { "value" : 0.09890000, "n" : 1, "scriptPubKey" : { "asm" : "OP_DUP OP_HASH160 d6c492056f3f99692b56967a42b8ad44ce76b67a OP_EQUALVERIFY OP_CHECKSIG", "hex" : "76a914d6c492056f3f99692b56967a42b8ad44ce76b67a88ac", "reqSigs" : 1, "type" : "pubkeyhash", "addresses" : [ "1Lab618UuWjLmVA1Q64tHZXcLoc4397ZX3" ] } } ] } |
至此,一個“空白交易”就構造好了,尚未使用私鑰對交易進行簽名,欄位scriptSig
是留空的,無簽名的交易是無效的。此時的Tx ID並不是最終的Tx ID,填入簽名後Tx ID會發生變化。
在手動建立交易時,務必注意輸入、輸出的值,非常容易犯錯的是忘記構造找零輸出
(如非必要勿手動構造交易)。曾經有人構造交易時忘記找零,發生了支付 200 BTC 的礦工費的人間慘劇,所幸的是收錄該筆交易的Block由著名挖礦團隊“烤貓(Friedcat)”挖得,該團隊非常厚道的退回了多餘費用。
3. 簽名
交易簽名使用命令:
1 2 3 |
signrawtransaction <hex string> \ [{"txid":txid,"vout":n,"scriptPubKey":hex,"redeemScript":hex},...] [<privatekey1>,...] \ [sighashtype="ALL"] |
- 第一個引數是建立的待簽名交易的十六進位制字串;
- 第二個引數有點類似建立交易時的引數,不過需要多出一個公鑰欄位
scriptPubKey
,其他節點驗證交易時是通過公鑰和簽名來完成的,所以要提供公鑰;如果是合成地址,則需要提供redeemScript
; - 第三個引數是即將花費的幣所在地址的私鑰,用來對交易進行簽名,如果該地址私鑰已經匯入至bitcoind中,則無需顯式提供;
- 最後一個引數表示簽名型別,在上一篇裡,介紹了三種交易簽名型別;
簽名之前需要找到scriptPubKey
,提取輸入交易資訊即可獲取(也可以根據其公鑰自行計算),由命令:getrawtransaction <txid> [verbose=0]
完成。
執行:
1 |
bitcoind getrawtransaction 296ea7bf981b44999d689853d17fe0ceb852a8a34e68fcd19f0a41e589132156 1 |
輸出:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 |
{ "hex" : "01000000010511331f639e974283d3909496787a660583dc88f41598d177e225b5f352314a000000006c493046022100be8c796122ec598295e6dfd6664a20a7e20704a17f76d3d925c9ec421ca60bc1022100cf9f2d7b9f24285f7c119c91f24521e5483f6b141de6ee55658fa70116ee04d4012103cad07f6de0b181891b5291a5bc82b228fe6509699648b0b53556dc0057eeb5a4ffffffff0160a62f01000000001976a914d6c492056f3f99692b56967a42b8ad44ce76b67a88ac00000000", "txid" : "296ea7bf981b44999d689853d17fe0ceb852a8a34e68fcd19f0a41e589132156", "version" : 1, "locktime" : 0, "vin" : [ { "txid" : "4a3152f3b525e277d19815f488dc8305667a78969490d38342979e631f331105", "vout" : 0, "scriptSig" : { "asm" : "3046022100be8c796122ec598295e6dfd6664a20a7e20704a17f76d3d925c9ec421ca60bc1022100cf9f2d7b9f24285f7c119c91f24521e5483f6b141de6ee55658fa70116ee04d401 03cad07f6de0b181891b5291a5bc82b228fe6509699648b0b53556dc0057eeb5a4", "hex" : "493046022100be8c796122ec598295e6dfd6664a20a7e20704a17f76d3d925c9ec421ca60bc1022100cf9f2d7b9f24285f7c119c91f24521e5483f6b141de6ee55658fa70116ee04d4012103cad07f6de0b181891b5291a5bc82b228fe6509699648b0b53556dc0057eeb5a4" }, "sequence" : 4294967295 } ], "vout" : [ { "value" : 0.19900000, "n" : 0, "scriptPubKey" : { "asm" : "OP_DUP OP_HASH160 d6c492056f3f99692b56967a42b8ad44ce76b67a OP_EQUALVERIFY OP_CHECKSIG", "hex" : "76a914d6c492056f3f99692b56967a42b8ad44ce76b67a88ac", "reqSigs" : 1, "type" : "pubkeyhash", "addresses" : [ "1Lab618UuWjLmVA1Q64tHZXcLoc4397ZX3" ] } } ], "blockhash" : "000000000000000488f18f7659acd85b2bd06a5ed2c4439eea74a8b968d16656", "confirmations" : 19, "time" : 1383235737, "blocktime" : 1383235737 } |
scriptPubKey
位於”vout”[0]->”scriptPubKey”->”hex”,即: 76a914d6c492056f3f99692b56967a42b8ad44ce76b67a88ac 。
簽名使用ECDSA演算法,對其,“空白交易”簽名之,執行:
1 2 3 |
bitcoind signrawtransaction \ "010000000156211389e5410a9fd1fc684ea3a852b8cee07fd15398689d99441b98bfa76e290000000000ffffffff0280969800000000001976a914fdc7990956642433ea75cabdcc0a9447c5d2b4ee88acd0e89600000000001976a914d6c492056f3f99692b56967a42b8ad44ce76b67a88ac00000000" \ '[{"txid":"296ea7bf981b44999d689853d17fe0ceb852a8a34e68fcd19f0a41e589132156","vout":0,"scriptPubKey":"76a914d6c492056f3f99692b56967a42b8ad44ce76b67a88ac"}]' |
輸出:
1 2 3 4 |
{ "hex" : "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", "complete" : true } |
簽名後,簽名值會填入上文所述的空欄位中,從而得到一個完整的交易。可通過上文介紹的命令decoderawtransaction <hex string>
解碼檢視之。
最後一步,就是將其廣播出去,等待網路傳播至所有節點,約10~60秒廣播至全球節點,取決與你的節點的網路連線狀況。稍後一些時刻,就會進入Block中。廣播由命令sendrawtransaction <hex string>
來完成。如果沒有執行節點,可以通過公共節點的API進行廣播,例如:blockchain.info/pushtx。
執行:
1 2 |
bitcoind sendrawtransaction \ "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" |
輸出:
1 |
b5f8da1ea9e02ec3cc0765f9600f49945e94ed4b0c88ed0648896bf3e213205d |
返回的是Transaction Hash值,即該交易的ID。至此,交易構造、簽名、傳送的完整過程完成了。
合成地址交易
合成地址以3開頭,可以實現多方管理資產,極大提高安全性,也可以輕鬆實現基於比特幣原生的三方交易擔保支付。一個M-of-N
的模式:
1 |
m {pubkey}...{pubkey} n OP_CHECKMULTISIG |
M和N需滿足:
1<=N<=3
1<=M<=N
可以是1 of 1
,1 of 2
,2 of 3
等組合,通常選擇N=3
:
1 of 3
,最大程度私鑰冗餘。防丟私鑰損失,3把私鑰中任意一把即可簽名發幣,即使丟失2把都可以保障不受損失;2 of 3
,提高私鑰冗餘度的同時解決單點信任問題。3把私鑰任意2把私鑰可簽名發幣,三方不完全信任的情形,即中介交易中,非常適用;3 of 3
,最大程度解決資金信任問題,無私鑰冗餘。必須3把私鑰全部簽名才能發幣,適用多方共同管理重要資產,但任何一方遺失私鑰均造成嚴重損失;
合成地址的交易構造、簽名、傳送過程與普通交易類似,這裡只介紹如何建立一個合成地址。大神Gavin Andresen已經演示過,下面內容摘自其gist.
首先,需要三對公鑰、私鑰。公鑰建立地址、私鑰用於簽名。
1 2 3 4 5 6 |
# No.1 0491bba2510912a5bd37da1fb5b1673010e43d2c6d812c514e91bfa9f2eb129e1c183329db55bd868e209aac2fbc02cb33d98fe74bf23f0c235d6126b1d8334f86 / 5JaTXbAUmfPYZFRwrYaALK48fN6sFJp4rHqq2QSXs8ucfpE4yQU # No.2 04865c40293a680cb9c020e7b1e106d8c1916d3cef99aa431a56d253e69256dac09ef122b1a986818a7cb624532f062c1d1f8722084861c5c3291ccffef4ec6874 / 5Jb7fCeh1Wtm4yBBg3q3XbT6B525i17kVhy3vMC9AqfR6FH2qGk # No.3 048d2455d2403e08708fc1f556002f1b6cd83f992d085097f9974ab08a28838f07896fbab08f39495e15fa6fad6edbfb1e754e35fa1c7844c41f322a1863d46213 / 5JFjmGo5Fww9p8gvx48qBYDJNAzR9pmH5S389axMtDyPT8ddqmw |
使用命令:createmultisig <nrequired> <'["key","key"]'>
來合成,其中key
為公鑰,建立地址時僅需公鑰。建立型別是2 of 3
.
輸入:
1 2 |
bitcoind createmultisig 2 \ '["0491bba2510912a5bd37da1fb5b1673010e43d2c6d812c514e91bfa9f2eb129e1c183329db55bd868e209aac2fbc02cb33d98fe74bf23f0c235d6126b1d8334f86","04865c40293a680cb9c020e7b1e106d8c1916d3cef99aa431a56d253e69256dac09ef122b1a986818a7cb624532f062c1d1f8722084861c5c3291ccffef4ec6874","048d2455d2403e08708fc1f556002f1b6cd83f992d085097f9974ab08a28838f07896fbab08f39495e15fa6fad6edbfb1e754e35fa1c7844c41f322a1863d46213"]' |
輸出:
1 2 3 4 |
{ "address" : "3QJmV3qfvL9SuYo34YihAf3sRCW3qSinyC", "redeemScript" : "52410491bba2510912a5bd37da1fb5b1673010e43d2c6d812c514e91bfa9f2eb129e1c183329db55bd868e209aac2fbc02cb33d98fe74bf23f0c235d6126b1d8334f864104865c40293a680cb9c020e7b1e106d8c1916d3cef99aa431a56d253e69256dac09ef122b1a986818a7cb624532f062c1d1f8722084861c5c3291ccffef4ec687441048d2455d2403e08708fc1f556002f1b6cd83f992d085097f9974ab08a28838f07896fbab08f39495e15fa6fad6edbfb1e754e35fa1c7844c41f322a1863d4621353ae" } |
得到的合成地址是:3QJmV3qfvL9SuYo34YihAf3sRCW3qSinyC
,該地址沒有公鑰,僅有redeemScript
,作用與公鑰相同。後續的構造、簽名、傳送過程與上文普通地址交易類似,略去。