How to fully decode a coinbase transaction?

Question

After reading this What is the format of the coinbase transaction? I was wondering about a few things.

decoderawtransaction of a random Litecoin coinbase transaction:

"coinbase" : "038abd07062f503253482f048725ee5208083865a409000000092f7374726174756d2f",
...
    "scriptPubKey" : {
    "asm" : "OP_DUP OP_HASH160 975efcba1e058667594dc57146022ec46560a63c OP_EQUALVERIFY OP_CHECKSIG",
    "hex" : "76a914975efcba1e058667594dc57146022ec46560a63c88ac",
..
    "addresses" : [
    "LZ2L61M8rCoZmK7SemTBqfxuFZv5Uj4peR"

Is the asm field the outgoing address? If yes how is it encoded and what is the hex field for? Same question goes for scriptSig asm field in a normal transaction. It contains the public key and the signature but how is it structured/encoded. Because I have a Tx with to vins from the same address and I don't see the same public key in the asm field.

How do I read the coinbase? Hex2asic gives me "?????/P2SH/??%?R??8e??????/stratum/". Is that all I can do if I don't know how the pool operator has structured the coinbase?

Answer 1

coinbase, scriptPubKey, scriptSig - they are all scripts. You can read in wiki about how to decode script https://en.bitcoin.it/wiki/Script.

Coinbase can contain any data, even invalid script. But typically, it contains valid scripts. Examples of decoding:

coinbase: 038abd07062f503253482f048725ee5208083865a409000000092f7374726174756d2f
03 - length opcode
8abd07 - data with length 03
06 - length opcode
2f503253482f - data with length 06
04 - length opcode
8725ee52 - data with length 04
08 - length opcode
083865a409000000 - data with length 08
09 - length opcode
2f7374726174756d2f - data with length 09

scriptPubKey: 76a914975efcba1e058667594dc57146022ec46560a63c88ac
76 - OP_DUP opcode
a9 - HASH160 opcode
14 - length opcode
975efcba1e058667594dc57146022ec46560a63c - data with length 14 (20 in dec)
88 - OP_EQUALVERIFY opcode
ac - OP_CHECKSIG opcode