clef: external signing fixes + signing data (#19003)

* signer/clef: make use of json-rpc notification

* signer: tidy up output of OnApprovedTx

* accounts/external, signer: implement remote signing of text, make accounts_sign take hexdata

* clef: added basic testscript

* signer, external, api: add clique signing test to debug rpc, fix clique signing in clef

* signer: fix clique interoperability between geth and clef

* clef: rename networkid switch to chainid

* clef: enable chainid flag

* clef, signer: minor changes from review

* clef: more tests for signer

cmd/clef/tests/testsigner.js

@@ -0,0 +1,73 @@
+// This file is a test-utility for testing clef-functionality
+//
+// Start clef with
+//
+// build/bin/clef --4bytedb=./cmd/clef/4byte.json --rpc
+//
+// Start geth with
+//
+// build/bin/geth --nodiscover --maxpeers 0 --signer http://localhost:8550 console --preload=cmd/clef/tests/testsigner.js
+//
+// and in the console simply invoke
+//
+// > test()
+//
+// You can reload the file via `reload()`
+
+function reload(){
+	loadScript("./cmd/clef/tests/testsigner.js");
+}
+
+function init(){
+    if (typeof accts == 'undefined' || accts.length == 0){
+        accts = eth.accounts
+        console.log("Got accounts ", accts);
+    }
+}
+init()
+function testTx(){
+    if( accts && accts.length > 0) {
+        var a = accts[0]
+        var txdata = eth.signTransaction({from: a, to: a, value: 1, nonce: 1, gas: 1, gasPrice: 1})
+        var v = parseInt(txdata.tx.v)
+        console.log("V value: ", v)
+        if (v == 37 || v == 38){
+            console.log("Mainnet 155-protected chainid was used")
+        }
+        if (v == 27 || v == 28){
+            throw new Error("Mainnet chainid was used, but without replay protection!")
+        }
+    }
+}
+function testSignText(){
+    if( accts && accts.length > 0){
+        var a = accts[0]
+        var r = eth.sign(a, "0x68656c6c6f20776f726c64"); //hello world
+        console.log("signing response",  r)
+    }
+}
+function testClique(){
+    if( accts && accts.length > 0){
+        var a = accts[0]
+        var r = debug.testSignCliqueBlock(a, 0); // Sign genesis
+        console.log("signing response",  r)
+        if( a != r){
+            throw new Error("Requested signing by "+a+ " but got sealer "+r)
+        }
+    }
+}
+
+function test(){
+    var tests = [
+        testTx,
+        testSignText,
+        testClique,
+    ]
+    for( i in tests){
+        try{
+            tests[i]()
+        }catch(err){
+            console.log(err)
+        }
+    }
+ }