上文讲解了一笔交易中存在一个输入和一个输出的情况，一个输入和多个输出的情形与之处理方式一样，不再赘述。本文着重讲解多个输入的交易，如何完成签名。
以一个包含两个输入和两个输出的交易为例，其它更多输入和输出的交易实现，原理一致。
下面是根据交易数据结构，通过查询各自输入对应上一笔输出，找到各自的输出脚本后，完成全部填充后的一笔交易信息：
{
"txid": "6f92259760fb24fc81f06cfe984c33d883724d655243824b755d763a2180609c",
"hash": "6f92259760fb24fc81f06cfe984c33d883724d655243824b755d763a2180609c",
"size": 185,
"vsize": 185,
"version": 1,
"locktime": 0,
"vin": [
{
"txid": "350216356afc5ddb2143786318f9ccbee97abbcc5c9f4cfadbbb4d5c8dc3ccd9",
"vout": 0,
"scriptSig": {
"asm": "OP_DUP OP_HASH160 b2fd829c977a49044cd21e8762a99ce670800dbe OP_EQUALVERIFY OP_CHECKSIG",
"hex": "76a914b2fd829c977a49044cd21e8762a99ce670800dbe88ac"
},
"sequence": 4294967295
},
{
"txid": "dffdc8363aa6ddcaa7df62a8eeef635cc248b778da245e1d99c303148e1f5d24",
"vout": 0,
"scriptSig": {
"asm": "OP_DUP OP_HASH160 c8e9a628b5d1e49020efc51153fab992213d96fa OP_EQUALVERIFY OP_CHECKSIG",
"hex": "76a914c8e9a628b5d1e49020efc51153fab992213d96fa88ac"
},
"sequence": 4294967295
}
],
"vout": [
{
"value": 188638,
"n": 0,
"scriptPubKey": {
"asm": "OP_DUP OP_HASH160 ad46f3b798adeb378f732a864ccf4516b8d02c6a OP_EQUALVERIFY OP_CHECKSIG",
"hex": "76a914ad46f3b798adeb378f732a864ccf4516b8d02c6a88ac",
"reqSigs": 1,
"type": "pubkeyhash",
"addresses": [
"1GoCu28SQu17FGEc4cv3of9ugwAcoPxGqE"
]
}
},
{
"value": 200000,
"n": 1,
"scriptPubKey": {
"asm": "OP_DUP OP_HASH160 ed5f9b6dce1fdcdb0c904b2b6928d5e25594ad23 OP_EQUALVERIFY OP_CHECKSIG",
"hex": "76a914ed5f9b6dce1fdcdb0c904b2b6928d5e25594ad2388ac",
"reqSigs": 1,
"type": "pubkeyhash",
"addresses": [
"1Ne7gN9gUUpDp3JWK32bZyRH8ixCyPJQJa"
]
}
}
]
}
如结构所示，总共两个输入，每个输入对应的上一个输出脚本也都填充好了，那么，签名的时候，都用这一份原始交易数据内容么？
1、理解的偏差
因为我最先实现的一对一交易，所以在构建多对多的交易数据时，我想当然认为，在对原始数据填充输入脚本这部分的操作应该这么做：
a、找到输入1的上一笔输出交易信息，从该信息中提取出属于自己的输出脚本，填充到本次交易输入1的脚本域中；
b、找到输入2的上一笔输出交易信息，从该信息中提取出属于自己的输出脚本，填充到本次交易输入2的脚本域中；
c、完成本次交易整个数据的赋值和填充后，形成一个原始交易数据；
d、将步骤c的原始交易数据用输入1对应的私钥进行签名，得到sign1，将其重新回填到输入1 的脚本域；
e、将步骤c的原始交易数据用输入2对应的私钥进行签名，得到sign2，将其重新回填到输入2的脚本域；
f、完成上述步骤后，得到真正可以广播出去的交易数据。
我按照以上思路做完签名后，发现数据广播出去失败，返回错误，提示该交易数据签名数据错误。
2、真正的原始交易数据
出现问题后上网搜索一遍，发现没有这方面的任何解答，好在公司能上外网，终于找到一个国外同行们的解答：
https://bitcoin.stackexchange.com/questions/41209/how-to-sign-a-transaction-with-multiple-inputs
通过阅读理解，再结合keepkey的firmware源码中该部分的实现，整理出来处理思路如下：
1、对于多个输入的交易签名，在构建原始交易数据时，本着用谁的私钥签名，就先填充谁的脚本域的原则，比如，现在要用输入1对应的私钥对这笔交易进行签名，那么在构建原始交易数据时，其它的输入中的脚本域不做填充，并且赋值script_len =0。
2、构建一个原始交易1，用私钥1来完成签名，得到sign1，原始交易1的数据结构如下：
0100000002d9ccc38d5c4dbbdbfa4c9f5cccbb7ae9beccf91863784321db5dfc6a35160235000000001976a914b2fd829c977a49044cd21e8762a99ce670800dbe88acffffffff245d1f8e1403c3991d5e24da78b748c25c63efeea862dfa7cadda63a36c8fddf0000000000ffffffff02dee00200000000001976a914ad46f3b798adeb378f732a864ccf4516b8d02c6a88ac400d0300000000001976a914ed5f9b6dce1fdcdb0c904b2b6928d5e25594ad2388ac0000000001000000
{
"txid": "6f92259760fb24fc81f06cfe984c33d883724d655243824b755d763a2180609c",
"hash": "6f92259760fb24fc81f06cfe984c33d883724d655243824b755d763a2180609c",
"size": 185,
"vsize": 185,
"version": 1,
"locktime": 0,
"vin": [
{
"txid": "350216356afc5ddb2143786318f9ccbee97abbcc5c9f4cfadbbb4d5c8dc3ccd9",
"vout": 0,
"scriptSig": {
"asm": "OP_DUP OP_HASH160 b2fd829c977a49044cd21e8762a99ce670800dbe OP_EQUALVERIFY OP_CHECKSIG",
"hex": "76a914b2fd829c977a49044cd21e8762a99ce670800dbe88ac"
},
"sequence": 4294967295
},
{
"txid": "dffdc8363aa6ddcaa7df62a8eeef635cc248b778da245e1d99c303148e1f5d24",
"vout": 0,
"scriptSig": {
"asm": "",
"hex": ""
},
"sequence": 4294967295
}
],
"vout": [
{
"value": 188638,
"n": 0,
"scriptPubKey": {
"asm": "OP_DUP OP_HASH160 ad46f3b798adeb378f732a864ccf4516b8d02c6a OP_EQUALVERIFY OP_CHECKSIG",
"hex": "76a914ad46f3b798adeb378f732a864ccf4516b8d02c6a88ac",
"reqSigs": 1,
"type": "pubkeyhash",
"addresses": [
"1GoCu28SQu17FGEc4cv3of9ugwAcoPxGqE"
]
}
},
{
"value": 200000,
"n": 1,
"scriptPubKey": {
"asm": "OP_DUP OP_HASH160 ed5f9b6dce1fdcdb0c904b2b6928d5e25594ad23 OP_EQUALVERIFY OP_CHECKSIG",
"hex": "76a914ed5f9b6dce1fdcdb0c904b2b6928d5e25594ad2388ac",
"reqSigs": 1,
"type": "pubkeyhash",
"addresses": [
"1Ne7gN9gUUpDp3JWK32bZyRH8ixCyPJQJa"
]
}
}
]
}
得到的sign1如下：
473044022073d0210a320b3d6ce3088da58e9f31dd87fda550762b248b794172b3ccaac13902205da717b785a4219518cd3f5903d130886c2b8905c543abb389fbbafa41e90c300141043d23e5f0758a53e2a18c8156051ca136d4639db5ceace580583983151113c1e5dcd7523f777fcd5b7ba16fef8dcbf4c2dbcaf91dd0c5d72080703517b96c4994
3、在构建第二个原始交易2，用私钥2完成签名，得到sign2。原始交易1的数据结构如下：
0100000002d9ccc38d5c4dbbdbfa4c9f5cccbb7ae9beccf91863784321db5dfc6a351602350000000000ffffffff245d1f8e1403c3991d5e24da78b748c25c63efeea862dfa7cadda63a36c8fddf000000001976a914c8e9a628b5d1e49020efc51153fab992213d96fa88acffffffff02dee00200000000001976a914ad46f3b798adeb378f732a864ccf4516b8d02c6a88ac400d0300000000001976a914ed5f9b6dce1fdcdb0c904b2b6928d5e25594ad2388ac0000000001000000
{
"txid": "55b61a575943ed9718989dabb4d8b5cdd90d3097d375f0354274894894f06ce5",
"hash": "55b61a575943ed9718989dabb4d8b5cdd90d3097d375f0354274894894f06ce5",
"size": 185,
"vsize": 185,
"version": 1,
"locktime": 0,
"vin": [
{
"txid": "350216356afc5ddb2143786318f9ccbee97abbcc5c9f4cfadbbb4d5c8dc3ccd9",
"vout": 0,
"scriptSig": {
"asm": "",
"hex": ""
},
"sequence": 4294967295
},
{
"txid": "dffdc8363aa6ddcaa7df62a8eeef635cc248b778da245e1d99c303148e1f5d24",
"vout": 0,
"scriptSig": {
"asm": "OP_DUP OP_HASH160 c8e9a628b5d1e49020efc51153fab992213d96fa OP_EQUALVERIFY OP_CHECKSIG",
"hex": "76a914c8e9a628b5d1e49020efc51153fab992213d96fa88ac"
},
"sequence": 4294967295
}
],
"vout": [
{
"value": 188638,
"n": 0,
"scriptPubKey": {
"asm": "OP_DUP OP_HASH160 ad46f3b798adeb378f732a864ccf4516b8d02c6a OP_EQUALVERIFY OP_CHECKSIG",
"hex": "76a914ad46f3b798adeb378f732a864ccf4516b8d02c6a88ac",
"reqSigs": 1,
"type": "pubkeyhash",
"addresses": [
"1GoCu28SQu17FGEc4cv3of9ugwAcoPxGqE"
]
}
},
{
"value": 200000,
"n": 1,
"scriptPubKey": {
"asm": "OP_DUP OP_HASH160 ed5f9b6dce1fdcdb0c904b2b6928d5e25594ad23 OP_EQUALVERIFY OP_CHECKSIG",
"hex": "76a914ed5f9b6dce1fdcdb0c904b2b6928d5e25594ad2388ac",
"reqSigs": 1,
"type": "pubkeyhash",
"addresses": [
"1Ne7gN9gUUpDp3JWK32bZyRH8ixCyPJQJa"
]
}
}
]
}
得到的sign2如下：
47304402207f179bbf1ba47beaa80f9916c587700e1ed5141f2476bd803c6ec3bc953c0d1a0220662fee1ed87879f8ef5cc6877068dea9906809f86e22f713a4e674986f0647b8014104e152cd7210e4c2a0791514ca2d7d75e0bf25c7763488ffe73694c7d10b21471fe6ccdada299c6ab5d61ea7c13f3c480516cc980cab0820d7f67dbcc1da2831d1
.........
n、完成所有的签名后，分别将sign1、sign2......分别重新回填到各自的输入脚本域中，更新各自的script_len值，最终形成真正能够广播的交易数据：
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
{
"txid": "4ec1953b1e468b4f965b7eac307023ea801a5a75f0adef7387c500c06d2ae5ce",
"hash": "4ec1953b1e468b4f965b7eac307023ea801a5a75f0adef7387c500c06d2ae5ce",
"size": 436,
"vsize": 436,
"version": 1,
"locktime": 0,
"vin": [
{
"txid": "350216356afc5ddb2143786318f9ccbee97abbcc5c9f4cfadbbb4d5c8dc3ccd9",
"vout": 0,
"scriptSig": {
"asm": "3044022073d0210a320b3d6ce3088da58e9f31dd87fda550762b248b794172b3ccaac13902205da717b785a4219518cd3f5903d130886c2b8905c543abb389fbbafa41e90c30[ALL] 043d23e5f0758a53e2a18c8156051ca136d4639db5ceace580583983151113c1e5dcd7523f777fcd5b7ba16fef8dcbf4c2dbcaf91dd0c5d72080703517b96c4994",
"hex": "473044022073d0210a320b3d6ce3088da58e9f31dd87fda550762b248b794172b3ccaac13902205da717b785a4219518cd3f5903d130886c2b8905c543abb389fbbafa41e90c300141043d23e5f0758a53e2a18c8156051ca136d4639db5ceace580583983151113c1e5dcd7523f777fcd5b7ba16fef8dcbf4c2dbcaf91dd0c5d72080703517b96c4994"
},
"sequence": 4294967295
},
{
"txid": "dffdc8363aa6ddcaa7df62a8eeef635cc248b778da245e1d99c303148e1f5d24",
"vout": 0,
"scriptSig": {
"asm": "304402207f179bbf1ba47beaa80f9916c587700e1ed5141f2476bd803c6ec3bc953c0d1a0220662fee1ed87879f8ef5cc6877068dea9906809f86e22f713a4e674986f0647b8[ALL] 04e152cd7210e4c2a0791514ca2d7d75e0bf25c7763488ffe73694c7d10b21471fe6ccdada299c6ab5d61ea7c13f3c480516cc980cab0820d7f67dbcc1da2831d1",
"hex": "47304402207f179bbf1ba47beaa80f9916c587700e1ed5141f2476bd803c6ec3bc953c0d1a0220662fee1ed87879f8ef5cc6877068dea9906809f86e22f713a4e674986f0647b8014104e152cd7210e4c2a0791514ca2d7d75e0bf25c7763488ffe73694c7d10b21471fe6ccdada299c6ab5d61ea7c13f3c480516cc980cab0820d7f67dbcc1da2831d1"
},
"sequence": 4294967295
}
],
"vout": [
{
"value": 188638,
"n": 0,
"scriptPubKey": {
"asm": "OP_DUP OP_HASH160 ad46f3b798adeb378f732a864ccf4516b8d02c6a OP_EQUALVERIFY OP_CHECKSIG",
"hex": "76a914ad46f3b798adeb378f732a864ccf4516b8d02c6a88ac",
"reqSigs": 1,
"type": "pubkeyhash",
"addresses": [
"1GoCu28SQu17FGEc4cv3of9ugwAcoPxGqE"
]
}
},
{
"value": 200000,
"n": 1,
"scriptPubKey": {
"asm": "OP_DUP OP_HASH160 ed5f9b6dce1fdcdb0c904b2b6928d5e25594ad23 OP_EQUALVERIFY OP_CHECKSIG",
"hex": "76a914ed5f9b6dce1fdcdb0c904b2b6928d5e25594ad2388ac",
"reqSigs": 1,
"type": "pubkeyhash",
"addresses": [
"1Ne7gN9gUUpDp3JWK32bZyRH8ixCyPJQJa"
]
}
}
]
}
以上数据都是真正在BTC网络上实现交易的，请各位查阅。
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1HKQyLvLL4zCsbewjxdbV9WsCmqyaZYUUT
