solana-labs · CriesofCarrots · Feb 26, 2020 · Feb 17, 2020 · Feb 17, 2020 · Feb 26, 2020
diff --git a/docs/src/SUMMARY.md b/docs/src/SUMMARY.md
@@ -3,6 +3,8 @@
 * [Introduction](introduction.md)
 * [Using Solana from the Command-line](cli/README.md)
   * [Command-line Usage](cli/usage.md)
+  * [Remote Wallet](remote-wallet/README.md)
+    * [Ledger Hardware Wallet](remote-wallet/ledger.md)
   * [Paper Wallet](paper-wallet/README.md)
     * [Installation](paper-wallet/installation.md)
     * [Paper Wallet Usage](paper-wallet/usage.md)

diff --git a/docs/src/remote-wallet/README.md b/docs/src/remote-wallet/README.md
@@ -0,0 +1,12 @@
+# Remote Wallet
+
+This document describes how to use a remote wallet with the Solana CLI
+tools. Currently, Solana supports:
+- Ledger hardware wallet (Nano S)
+
+## Overview
+
+Solana's remote-wallet integration provides Solana CLI methods to query a
+device's BIP32 public keys and send messages to the device for secure signing.
+
+{% page-ref page="ledger.md" %}
diff --git a/docs/src/remote-wallet/ledger.md b/docs/src/remote-wallet/ledger.md
@@ -0,0 +1,132 @@
+# Ledger Hardware Wallet
+
+The Ledger Nano S hardware wallet offers secure storage of your Solana private
+keys. The Solana Ledger app enables derivation of essentially infinite keys, and
+secure transaction signing.
+
+## Before You Begin
+
+- [Initialize your Ledger Nano S](https://support.ledger.com/hc/en-us/articles/360000613793)
+- [Install the latest device firmware](https://support.ledgerwallet.com/hc/en-us/articles/360002731113-Update-Ledger-Nano-S-firmware)
+- [Install Ledger Live](https://support.ledger.com/hc/en-us/articles/360006395553/) software on your computer
+
+## Install the Solana App on Ledger Nano S
+
+1. Open the Manager in Ledger Live
+2. Connect and unlock your Ledger Nano S
+3. If asked, allow the manager on your device by pressing the right button
+4. Find Solana in the app catalog and click Install
+5. An installation window appears and your device will display Processing…
+6. The app installation is confirmed
+
+## Use Ledger Device with Solana CLI
+
+1. Plug your Ledger device into your computer's USB port
+2. Enter your pin and start the Solana app on the Ledger device
+3. On your computer, run:
+
+```text
+solana address --keypair usb://ledger
+```
+
+This confirms your Ledger device is connected properly and in the correct state
+to interact with the Solana CLI. The command returns your Ledger's unique
+*wallet key*. When you have multiple Nano S devices connected to the same
+computer, you can use your wallet key to specify which Ledger hardware wallet
+you want to use. Run the same command again, but this time, with its fully
+qualified URL:
+
+```text
+solana address --keypair usb://ledger/nano-s/<WALLET_KEY>
+```
+
+Confirm it prints the same key as when you entered just `usb://ledger`.
+
+### Ledger Device URLs
+
+Solana defines a format for the URL protocol "usb://" to uniquely locate any Solana key on
+any remote wallet connected to your computer.
+
+The URL has the form, where square brackets denote optional fields:
+
+```text
+usb://ledger[/<LEDGER_TYPE>[/<WALLET_KEY>]][?key=<DERIVATION_PATH>]
+```
+
+`LEDGER_TYPE` is optional and defaults to the value "nano-s". If the value is provided,
+it must be "nano-s" without quotes, the only supported Ledger device at this time.
+
+`WALLET_KEY` is used to disambiguate multiple Nano S devices. Every Ledger has
+a unique master key and from that key derives a separate unique key per app.
+
+`DERVIATION_PATH` is used to navigate to Solana keys within your Ledger hardware
+wallet. The path has the form `<ACCOUNT>[/<CHANGE>]`, where each `ACCOUNT` and
+`CHANGE` are postive integers.
+
+All derivation paths implicitly include the prefix `44'/501'`, which indicates
+the path follows the [BIP44 specifications](https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki)
+and that any dervied keys are Solana keys (Coin type 501).  The single quote
+indicates a "hardened" derivation. Because Solana uses Ed25519 keypairs, all
+derivations are hardened and therefore adding the quote is optional and
+unnecessary.
+
+For example, a complete Ledger device path might be:
+
+```text
+usb://ledger/nano-s/BsNsvfXqQTtJnagwFWdBS7FBXgnsK8VZ5CmuznN85swK?key=0/0
+```
+
+### Set CLI Configuration
+
+If you want to set a Ledger key as the default signer for CLI commands, use the
+[CLI configuration settings](../cli/usage.md#solana-config):
+
+```text
+solana config set --keypair <LEDGER_URL>
+```
+
+For example:
+
+```text
+solana config set --keypair usb://ledger?key=0
+```
+
+### Check Account Balance
+
+```text
+solana balance --keypair usb://ledger?key=12345
+```
+
+Or with the default signer:
+
+```text
+solana balance
+```
+
+### Send SOL via Ledger Device
+
+```text
+solana transfer <RECIPIENT> <AMOUNT> --from <LEDGER_URL>
+```
+
+Or with the default signer:
+
+```text
+solana transfer <RECIPIENT> <AMOUNT>
+```
+
+### Delegate Stake with Ledger Device
+
+```text
+solana delegate-stake <STAKE_ACCOUNT> <VOTER_ID> --keypair <LEDGER_URL>
+```
+
+Or with the default signer:
+
+```text
+solana delegate-stake <STAKE_ACCOUNT> <VOTER_ID>
+```
+
+## Support
+
+Email maintainers@solana.com
diff --git a/remote-wallet/src/ledger.rs b/remote-wallet/src/ledger.rs
@@ -43,7 +43,7 @@ const HID_PREFIX_ZERO: usize = 0;
 
 mod commands {
     #[allow(dead_code)]
-    pub const GET_APP_CONFIGURATION: u8 = 0x06;
+    pub const GET_APP_CONFIGURATION: u8 = 0x01;
     pub const GET_PUBKEY: u8 = 0x02;
     pub const SIGN_MESSAGE: u8 = 0x03;
 }
@@ -76,7 +76,7 @@ impl LedgerWallet {
     //		* APDU_INS				(1 byte)
     //		* APDU_P1				(1 byte)
     //		* APDU_P2				(1 byte)
-    //		* APDU_LENGTH				(1 byte)
+    //		* APDU_LENGTH				(2 bytes)
     //		* APDU_Payload				(Variable)
     //
     fn write(&self, command: u8, p1: u8, p2: u8, data: &[u8]) -> Result<(), RemoteWalletError> {
@@ -141,11 +141,6 @@ impl LedgerWallet {
     //		* Payload				(Optional)
     //
     // Payload
-    //		* APDU Total Length			(2 bytes big endian)
-    //		* APDU_CLA				(1 byte)
-    //		* APDU_INS				(1 byte)
-    //		* APDU_P1				(1 byte)
-    //		* APDU_P2				(1 byte)
     //		* APDU_LENGTH				(1 byte)
     //		* APDU_Payload				(Variable)
     //