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

common/types_test.go

@@ -18,6 +18,7 @@ package common
 
 import (
 	"encoding/json"
+
 	"math/big"
 	"strings"
 	"testing"
@@ -149,3 +150,46 @@ func BenchmarkAddressHex(b *testing.B) {
 		testAddr.Hex()
 	}
 }
+
+func TestMixedcaseAccount_Address(t *testing.T) {
+
+	// https://github.com/ethereum/EIPs/blob/master/EIPS/eip-55.md
+	// Note: 0X{checksum_addr} is not valid according to spec above
+
+	var res []struct {
+		A     MixedcaseAddress
+		Valid bool
+	}
+	if err := json.Unmarshal([]byte(`[
+		{"A" : "0xae967917c465db8578ca9024c205720b1a3651A9", "Valid": false},
+		{"A" : "0xAe967917c465db8578ca9024c205720b1a3651A9", "Valid": true},
+		{"A" : "0XAe967917c465db8578ca9024c205720b1a3651A9", "Valid": false},
+		{"A" : "0x1111111111111111111112222222222223333323", "Valid": true}
+		]`), &res); err != nil {
+		t.Fatal(err)
+	}
+
+	for _, r := range res {
+		if got := r.A.ValidChecksum(); got != r.Valid {
+			t.Errorf("Expected checksum %v, got checksum %v, input %v", r.Valid, got, r.A.String())
+		}
+	}
+
+	//These should throw exceptions:
+	var r2 []MixedcaseAddress
+	for _, r := range []string{
+		`["0x11111111111111111111122222222222233333"]`,     // Too short
+		`["0x111111111111111111111222222222222333332"]`,    // Too short
+		`["0x11111111111111111111122222222222233333234"]`,  // Too long
+		`["0x111111111111111111111222222222222333332344"]`, // Too long
+		`["1111111111111111111112222222222223333323"]`,     // Missing 0x
+		`["x1111111111111111111112222222222223333323"]`,    // Missing 0
+		`["0xG111111111111111111112222222222223333323"]`,   //Non-hex
+	} {
+		if err := json.Unmarshal([]byte(r), &r2); err == nil {
+			t.Errorf("Expected failure, input %v", r)
+		}
+
+	}
+
+}