cmd/clef, signer: initial poc of the standalone signer (#16154)

* signer: introduce external signer command

* cmd/signer, rpc: Implement new signer. Add info about remote user to Context

* signer: refactored request/response, made use of urfave.cli

* cmd/signer: Use common flags

* cmd/signer: methods to validate calldata against abi

* cmd/signer: work on abi parser

* signer: add mutex around UI

* cmd/signer: add json 4byte directory, remove passwords from api

* cmd/signer: minor changes

* cmd/signer: Use ErrRequestDenied, enable lightkdf

* cmd/signer: implement tests

* cmd/signer: made possible for UI to modify tx parameters

* cmd/signer: refactors, removed channels in ui comms, added UI-api via stdin/out

* cmd/signer: Made lowercase json-definitions, added UI-signer test functionality

* cmd/signer: update documentation

* cmd/signer: fix bugs, improve abi detection, abi argument display

* cmd/signer: minor change in json format

* cmd/signer: rework json communication

* cmd/signer: implement mixcase addresses in API, fix json id bug

* cmd/signer: rename fromaccount, update pythonpoc with new json encoding format

* cmd/signer: make use of new abi interface

* signer: documentation

* signer/main: remove redundant  option

* signer: implement audit logging

* signer: create package 'signer', minor changes

* common: add 0x-prefix to mixcaseaddress in json marshalling + validation

* signer, rules, storage: implement rules + ephemeral storage for signer rules

* signer: implement OnApprovedTx, change signing response (API BREAKAGE)

* signer: refactoring + documentation

* signer/rules: implement dispatching to next handler

* signer: docs

* signer/rules: hide json-conversion from users, ensure context is cleaned

* signer: docs

* signer: implement validation rules, change signature of call_info

* signer: fix log flaw with string pointer

* signer: implement custom 4byte databsae that saves submitted signatures

* signer/storage: implement aes-gcm-backed credential storage

* accounts: implement json unmarshalling of url

* signer: fix listresponse, fix gas->uint64

* node: make http/ipc start methods public

* signer: add ipc capability+review concerns

* accounts: correct docstring

* signer: address review concerns

* rpc: go fmt -s

* signer: review concerns+ baptize Clef

* signer,node: move Start-functions to separate file

* signer: formatting

3 files changed, 18 insertions, 2 deletions

diff --git a/accounts/url.go b/accounts/url.go
index 47f9d8ee4..21df668ef 100644
--- a/accounts/url.go
+++ b/accounts/url.go
@@ -74,6 +74,22 @@ func (u URL) MarshalJSON() ([]byte, error) {
 	return json.Marshal(u.String())
 }
 
+// UnmarshalJSON parses url.
+func (u *URL) UnmarshalJSON(input []byte) error {
+	var textUrl string
+	err := json.Unmarshal(input, &textUrl)
+	if err != nil {
+		return err
+	}
+	url, err := parseURL(textUrl)
+	if err != nil {
+		return err
+	}
+	u.Scheme = url.Scheme
+	u.Path = url.Path
+	return nil
+}
+
 // Cmp compares x and y and returns:
 //
 //   -1 if x <  y
diff --git a/accounts/usbwallet/hub.go b/accounts/usbwallet/hub.go
index 61fc98ccc..640320bc9 100644
--- a/accounts/usbwallet/hub.go
+++ b/accounts/usbwallet/hub.go
@@ -127,7 +127,7 @@ func (hub *Hub) refreshWallets() {
 		// breaking the Ledger protocol if that is waiting for user confirmation. This
 		// is a bug acknowledged at Ledger, but it won't be fixed on old devices so we
 		// need to prevent concurrent comms ourselves. The more elegant solution would
-		// be to ditch enumeration in favor of hutplug events, but that don't work yet
+		// be to ditch enumeration in favor of hotplug events, but that don't work yet
 		// on Windows so if we need to hack it anyway, this is more elegant for now.
 		hub.commsLock.Lock()
 		if hub.commsPend > 0 { // A confirmation is pending, don't refresh
diff --git a/accounts/usbwallet/wallet.go b/accounts/usbwallet/wallet.go
index 8b3b5a522..6cef6e0fb 100644
--- a/accounts/usbwallet/wallet.go
+++ b/accounts/usbwallet/wallet.go
@@ -99,7 +99,7 @@ type wallet struct {
 	//
 	// As such, a hardware wallet needs two locks to function correctly. A state
 	// lock can be used to protect the wallet's software-side internal state, which
-	// must not be held exlusively during hardware communication. A communication
+	// must not be held exclusively during hardware communication. A communication
 	// lock can be used to achieve exclusive access to the device itself, this one
 	// however should allow "skipping" waiting for operations that might want to
 	// use the device, but can live without too (e.g. account self-derivation).