P2PK、P2PKH、P2SH、P2WPKH、P2WSH解析

P2PK、P2PKH、P2SH、P2WPKH、P2WSH解析

直接贴代码吧：

// payToPubKeyHashScript creates a new script to pay a transaction
// output to a 20-byte pubkey hash. It is expected that the input is a valid
// hash.
func payToPubKeyHashScript(pubKeyHash []byte) ([]byte, error) {
   return NewScriptBuilder().AddOp(OP_DUP).AddOp(OP_HASH160).
      AddData(pubKeyHash).AddOp(OP_EQUALVERIFY).AddOp(OP_CHECKSIG).
      Script()
}

// payToWitnessPubKeyHashScript creates a new script to pay to a version 0
// pubkey hash witness program. The passed hash is expected to be valid.
func payToWitnessPubKeyHashScript(pubKeyHash []byte) ([]byte, error) {
   return NewScriptBuilder().AddOp(OP_0).AddData(pubKeyHash).Script()
}

// payToScriptHashScript creates a new script to pay a transaction output to a
// script hash. It is expected that the input is a valid hash.
func payToScriptHashScript(scriptHash []byte) ([]byte, error) {
   return NewScriptBuilder().AddOp(OP_HASH160).AddData(scriptHash).
      AddOp(OP_EQUAL).Script()
}

// payToWitnessPubKeyHashScript creates a new script to pay to a version 0
// script hash witness program. The passed hash is expected to be valid.
func payToWitnessScriptHashScript(scriptHash []byte) ([]byte, error) {
   return NewScriptBuilder().AddOp(OP_0).AddData(scriptHash).Script()
}

// payToPubkeyScript creates a new script to pay a transaction output to a
// public key. It is expected that the input is a valid pubkey.
func payToPubKeyScript(serializedPubKey []byte) ([]byte, error) {
   return NewScriptBuilder().AddData(serializedPubKey).
      AddOp(OP_CHECKSIG).Script()
}

Pubkey scripts are created by spenders who have little interest what that script does. Receivers do care about the script conditions and, if they want, they can ask spenders to use a particular pubkey script. Unfortunately, custom pubkey scripts are less convenient than short Bitcoin addresses and there was no standard way to communicate them between programs prior to widespread implementation of the BIP70 Payment Protocol discussed later.

To solve these problems, pay-to-script-hash (P2SH) transactions were created in 2012 to let a spender create a pubkey script containing a hash of a second script, the redeem script.

The basic P2SH workflow, illustrated below, looks almost identical to the P2PKH workflow. Bob creates a redeem script with whatever script he wants, hashes the redeem script, and provides the redeem script hash to Alice. Alice creates a P2SH-style output containing Bob’s redeem script hash.

When Bob wants to spend the output, he provides his signature along with the full (serialized) redeem script in the signature script. The peer-to-peer network ensures the full redeem script hashes to the same value as the script hash Alice put in her output; it then processes the redeem script exactly as it would if it were the primary pubkey script, letting Bob spend the output if the redeem script does not return false.

The hash of the redeem script has the same properties as a pubkey hash—so it can be transformed into the standard Bitcoin address format with only one small change to differentiate it from a standard address. This makes collecting a P2SH-style address as simple as collecting a P2PKH-style address. The hash also obfuscates any public keys in the redeem script, so P2SH scripts are as secure as P2PKH pubkey hashes.

As of Bitcoin Core 0.9, the standard pubkey script types are:

P2PKH is the most common form of pubkey script used to send a transaction to one or multiple Bitcoin addresses.

Pubkey script: OP_DUP OP_HASH160  OP_EQUALVERIFY OP_CHECKSIG
Signature script:  

Pay To Script Hash (P2SH)

Pubkey script: OP_HASH160  OP_EQUAL
Signature script:  [sig] [sig...] 

Multisig

In  multisig   pubkey scripts , called  m-of-n ,  m  is the  minimum  number of  signatures  which must match a  public key ;  n  is the  number  of  public keys  being provided. Both  m  and  n  should be  opcodes   OP_1  through  OP_16 , corresponding to the number desired.

Because of an off-by-one error in the original Bitcoin implementation which must be preserved for compatibility, OP_CHECKMULTISIG consumes one more value from the stack than indicated by m, so the list of secp256k1 signatures in the signature script must be prefaced with an extra value (OP_0) which will be consumed but not used.

The signature script must provide signatures in the same order as the corresponding public keys appear in the pubkey script or redeem script. See the description in OP_CHECKMULTISIG for details.

Pubkey script:   [B pubkey] [C pubkey...]  OP_CHECKMULTISIG
Signature script: OP_0  [B sig] [C sig...]

Although it’s not a separate transaction type, this is a P2SH multisig with 2-of-3:

Pubkey script: OP_HASH160  OP_EQUAL
Redeem script:      OP_CHECKMULTISIG
Signature script: OP_0   

Pubkey

Pubkey script:  OP_CHECKSIG
Signature script: 

Null Data

Pubkey Script: OP_RETURN <0 to 40 bytes of data>
(Null data scripts cannot be spent, so there's no signature script.)

Non-Standard Transactions

If you create a  redeem script , hash it, and use the hash in a  P2SH output , the  network  sees only the hash, so it will accept the  output  as valid no matter what the  redeem script  says. This allows payment to non-standard scripts, and as of Bitcoin Core 0.11, almost all valid  redeem scripts  can be spent. The exception is scripts that use unassigned  NOP opcodes ; these  opcodes  are reserved for future  soft forks  and can only be relayed or mined by  nodes  that don’t follow the standard mempool policy

As of Bitcoin Core 0.9.3, standard transactions must also meet the following conditions:

• The transaction must be finalized: either its locktime must be in the past (or less than or equal to the current block height), or all of its sequence numbers must be 0xffffffff.

• The transaction must be smaller than 100,000 bytes. That’s around 200 times larger than a typical single-input, single-output P2PKH transaction.

• Each of the transaction’s signature scripts must be smaller than 1,650 bytes. That’s large enough to allow 15-of-15 multisig transactions in P2SH using compressed public keys.

• Bare (non-P2SH) multisig transactions which require more than 3 public keys are currently non-standard.

• The transaction’s signature script must only push data to the script evaluation stack. It cannot push new opcodes, with the exception of opcodes which solely push data to the stack.

• The transaction must not include any outputs which receive fewer than 1/3 as many satoshis as it would take to spend it in a typical input. That’s currently 546 satoshis for a P2PKH or P2SH output on a Bitcoin Core node with the default relay fee. Exception: standard null data outputs must receive zero satoshis.

Null Data

• The transaction must be smaller than 100,000 bytes. That’s around 200 times larger than a typical single-input, single-output P2PKH transaction.

• Each of the transaction’s signature scripts must be smaller than 1,650 bytes. That’s large enough to allow 15-of-15 multisig transactions in P2SH using compressed public keys.

• Bare (non-P2SH) multisig transactions which require more than 3 public keys are currently non-standard.

• The transaction’s signature script must only push data to the script evaluation stack. It cannot push new opcodes, with the exception of opcodes which solely push data to the stack.

• The transaction must not include any outputs which receive fewer than 1/3 as many satoshis as it would take to spend it in a typical input. That’s currently 546 satoshis for a P2PKH or P2SH output on a Bitcoin Core node with the default relay fee. Exception: standard null data outputs must receive zero satoshis.

The various options for what to sign are called signature hash types. There are three base SIGHASH types currently available:

• SIGHASH_ALL, the default, signs all the inputs and outputs, protecting everything except the signature scripts against modification.

• SIGHASH_NONE signs all of the inputs but none of the outputs, allowing anyone to change where the satoshis are going unless other signatures using other signature hash flags protect the outputs.

• SIGHASH_SINGLE the only output signed is the one corresponding to this input (the output with the same output index number as this input), ensuring nobody can change your part of the transaction but allowing other signers to change their part of the transaction. The corresponding output must exist or the value “1” will be signed, breaking the security scheme. This input, as well as other inputs, are included in the signature. The sequence numbers of other inputs are not included in the signature, and can be updated.

The base types can be modified with the SIGHASH_ANYONECANPAY (anyone can pay) flag, creating three new combined types:

• SIGHASH_ALL|SIGHASH_ANYONECANPAY signs all of the outputs but only this one input, and it also allows anyone to add or remove other inputs, so anyone can contribute additional satoshis but they cannot change how many satoshis are sent nor where they go.

• SIGHASH_NONE|SIGHASH_ANYONECANPAY signs only this one input and allows anyone to add or remove other inputs or outputs, so anyone who gets a copy of this input can spend it however they’d like.

• SIGHASH_SINGLE|SIGHASH_ANYONECANPAY signs this one input and its corresponding output. Allows anyone to add or remove other inputs.

Null Data

• The transaction must be smaller than 100,000 bytes. That’s around 200 times larger than a typical single-input, single-output P2PKH transaction.

• Each of the transaction’s signature scripts must be smaller than 1,650 bytes. That’s large enough to allow 15-of-15 multisig transactions in P2SH using compressed public keys.

• Bare (non-P2SH) multisig transactions which require more than 3 public keys are currently non-standard.

• The transaction’s signature script must only push data to the script evaluation stack. It cannot push new opcodes, with the exception of opcodes which solely push data to the stack.

• The transaction must not include any outputs which receive fewer than 1/3 as many satoshis as it would take to spend it in a typical input. That’s currently 546 satoshis for a P2PKH or P2SH output on a Bitcoin Core node with the default relay fee. Exception: standard null data outputs must receive zero satoshis.