completed importing

07_3_Integrating_with_Hardware_Wallets.md

@@ -2,9 +2,11 @@
 
 > :information_source: **NOTE:** This is a draft in progress, so that I can get some feedback from early reviewers. It is not yet ready for learning.
 
-One of the greatest powers of PSBTs is the ability to hand transactions off to hardware devices. This will be a great development tool for you if you continue to program with Bitcoin. However, you can't test it out if you're using one of the configurations we suggest for this course — a VM on Linode per [§2.2](https://github.com/BlockchainCommons/Learning-Bitcoin-from-the-Command-Line/blob/master/02_2_Setting_Up_a_Bitcoin-Core_VPS_with_StackScript.md) or an even more farflung option such an AWS per [§2.3](https://github.com/BlockchainCommons/Learning-Bitcoin-from-the-Command-Line/blob/master/02_3_Setting_Up_Bitcoin_Core_Other.md) — because obviously you won't  have any way to hook a hardware device up to your remote, virtual machine
+One of the greatest powers of PSBTs is the ability to hand transactions off to hardware devices. This will be a great development tool for you if you continue to program with Bitcoin. However, you can't test it out if you're using one of the configurations we suggest for this course — a VM on Linode per [§2.2](https://github.com/BlockchainCommons/Learning-Bitcoin-from-the-Command-Line/blob/master/02_2_Setting_Up_a_Bitcoin-Core_VPS_with_StackScript.md) or an even more farflung option such an AWS per [§2.3](https://github.com/BlockchainCommons/Learning-Bitcoin-from-the-Command-Line/blob/master/02_3_Setting_Up_Bitcoin_Core_Other.md) — because obviously you won't  have any way to hook a hardware device up to your remote, virtual machine.
 
-So, you have three options for moving through this chapter on hardware wallets: (1) read along without testing the code; (2) install Bitcoin on a local machine to fully test these commands; or (3) skip straight ahead to [Chapter 8: Expanding Bitcoin Transactions in Other Ways](08_0_Expanding_Bitcoin_Transactions_Other.md). We suggest option #1, but if you really want to test these commands out we'll also give some support for #2 by talking about using a Macintosh for testing (a hardware-platform supported by [Bitcoin Standup](https://github.com/BlockchainCommons/Bitcoin-Standup)).
+>: ***What is a Hardware Wallet?*** A hardware wallet is an electronic device that improves the security of cryptocurrency by maintaing all the private keys on the device, rather than ever putting them on a device directly connected to the internet. Wallets have specific protocols for providing online interactions, usually managed by a program through a USB port. In this case, we'll be managing them with `bitcoin-cli` and the `hwy.py` program.
+
+You have three options for moving through this chapter on hardware wallets: (1) read along without testing the code; (2) install Bitcoin on a local machine to fully test these commands; or (3) skip straight ahead to [Chapter 8: Expanding Bitcoin Transactions in Other Ways](08_0_Expanding_Bitcoin_Transactions_Other.md). We suggest option #1, but if you really want to test these commands out we'll also give some support for #2 by talking about using a Macintosh for testing (a hardware-platform supported by [Bitcoin Standup](https://github.com/BlockchainCommons/Bitcoin-Standup)).
 
 > :warning: **VERSION WARNING:** PSBTs are an innovation from Bitcoin Core v 0.17.0. Earlier versions of Bitcoin Core will not be able to work with the PSBT while it is in process (though they will still be able to recognize the final transaction). The HWI interface appeared in Bitcoin Core v 0.18.0, but as long as you are using our suggested setup with Bitcoin Standup, it should all be fully integrated.
 
@@ -150,9 +152,19 @@ Because you've created a second wallet, some commands will now require a `-rpcwa
 
 ### Importing the Keys
 
+We now have to import a list of addresses from the hardware wallet to watch. This is done with HWI's `getkeypool` command:
+```
 $ hwi -f 9a1d520b getkeypool --wpkh 0 1000
 [{"desc": "wpkh([9a1d520b/84h/1h/0h]tpubDD7KTtoGzK9GuWUQcr1uTJazsAkqoXhdrwGXWVix6nPpNZmSbagZWD4QSaMsyK8YohAirGDPrWdRiEpKzTFB7DrTrqfzHCn7yi5EsqeR93S/0/*)#qttxy592", "range": [0, 1000], "timestamp": "now", "internal": false, "keypool": true, "active": true, "watchonly": true}, {"desc": "wpkh([9a1d520b/84h/1h/0h]tpubDD7KTtoGzK9GuWUQcr1uTJazsAkqoXhdrwGXWVix6nPpNZmSbagZWD4QSaMsyK8YohAirGDPrWdRiEpKzTFB7DrTrqfzHCn7yi5EsqeR93S/1/*)#3lw8ep4j", "range": [0, 1000], "timestamp": "now", "internal": true, "keypool": true, "active": true, "watchonly": true}]
+```
+We ask for the first 1000 WPKH (native Segwit) addresses and receive two descriptors for a key pool: one for receiving addresses and one for change addresses.
 
+> :book: ***What is a key pool?*** A key pool is a group of pregenerated keys. Modern HD wallets generate key pools by continuing to to determine new hierarchical addresses based on the original seed. The idea of key pools was originally implemented to ease the backup requirements of wallets. This allowed a keypool to be generated, and then the wallet to be backed up, rather than requiring backups after every new address was created. The concept has also proven very useful in the modern day since it allows the importing of a whole set of future addresses from one device to another.
+
+These are the same sorts of descriptors that we learned about in [§3.5: Understanding the Descriptor](03_5_Understanding_the_Descriptor.md). At the time, we said that they were most useful for moving addresses among different machines. Here's the real-life example: moving addresses from a hardware wallet to Bitcoin Core node, so that our net-connected machine will be able to watch over them.
+
+Just as we learned in [§3.5](03_5_Understanding_the_Descriptor.md), you can examine these descriptors with the `getdescriptorinfo` RPC:
+```
 $ bitcoin-cli getdescriptorinfo "wpkh([9a1d520b/84h/1h/0h]tpubDD7KTtoGzK9GuWUQcr1uTJazsAkqoXhdrwGXWVix6nPpNZmSbagZWD4QSaMsyK8YohAirGDPrWdRiEpKzTFB7DrTrqfzHCn7yi5EsqeR93S/0/*)#qttxy592"
 {
   "descriptor": "wpkh([9a1d520b/84'/1'/0']tpubDD7KTtoGzK9GuWUQcr1uTJazsAkqoXhdrwGXWVix6nPpNZmSbagZWD4QSaMsyK8YohAirGDPrWdRiEpKzTFB7DrTrqfzHCn7yi5EsqeR93S/0/*)#n65e7wjf",
@@ -161,7 +173,11 @@ $ bitcoin-cli getdescriptorinfo "wpkh([9a1d520b/84h/1h/0h]tpubDD7KTtoGzK9GuWUQcr
   "issolvable": true,
   "hasprivatekeys": false
 }
+```
+As you'd expect, who do _not_ `hasprivatekeys`, because hardware wallets hold on to those.
 
+You can import the keys into your new `ledger` wallet using the `importmulti` RPC that you also met in [§3.5](03_5_Understanding_the_Descriptor.md). In this case, just put the entire response you got back from HWI in `'`s.
+```
 $ bitcoin-cli -rpcwallet=ledger importmulti '[{"desc": "wpkh([9a1d520b/84h/1h/0h]tpubDD7KTtoGzK9GuWUQcr1uTJazsAkqoXhdrwGXWVix6nPpNZmSbagZWD4QSaMsyK8YohAirGDPrWdRiEpKzTFB7DrTrqfzHCn7yi5EsqeR93S/0/*)#qttxy592", "range": [0, 1000], "timestamp": "now", "internal": false, "keypool": true, "active": true, "watchonly": true}, {"desc": "wpkh([9a1d520b/84h/1h/0h]tpubDD7KTtoGzK9GuWUQcr1uTJazsAkqoXhdrwGXWVix6nPpNZmSbagZWD4QSaMsyK8YohAirGDPrWdRiEpKzTFB7DrTrqfzHCn7yi5EsqeR93S/1/*)#3lw8ep4j", "range": [0, 1000], "timestamp": "now", "internal": true, "keypool": true, "active": true, "watchonly": true}]'
 [
   {
@@ -171,7 +187,20 @@ $ bitcoin-cli -rpcwallet=ledger importmulti '[{"desc": "wpkh([9a1d520b/84h/1h/0h
     "success": true
   }
 ]
-
+```
+You can now view the watch-only addresse that you received using the `getaddressesbylabel` command. All 1000 of the receive addresses are right there, in the `ledger` wallet!
+```
+$ bitcoin-cli -rpcwallet=ledger getaddressesbylabel "" | more
+{
+  "tb1qqqvnezljtmc9d7x52udpc0m9zgl9leugd2ur7y": {
+    "purpose": "receive"
+  },
+  "tb1qqzvrm6hujdt93qctuuev5qc4499tq9fdk0prwf": {
+    "purpose": "receive"
+  },
+...
+}
+```
 ## Create a Transaction with PSBT
 
 ## Summary: Integrating with Hardware Wallets