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

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

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

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).

cmd/clef/extapi_changelog.md

+### Changelog for external API
+
+
+
+#### 2.0.0
+
+* Commit `73abaf04b1372fa4c43201fb1b8019fe6b0a6f8d`, move `from` into `transaction` object in `signTransaction`. This
+makes the `accounts_signTransaction` identical to the old `eth_signTransaction`.
+
+
+#### 1.0.0
+
+Initial release.
+
+### Versioning
+
+The API uses [semantic versioning](https://semver.org/).
+
+TLDR; Given a version number MAJOR.MINOR.PATCH, increment the:
+
+* MAJOR version when you make incompatible API changes,
+* MINOR version when you add functionality in a backwards-compatible manner, and
+* PATCH version when you make backwards-compatible bug fixes.
+
+Additional labels for pre-release and build metadata are available as extensions to the MAJOR.MINOR.PATCH format.

cmd/clef/intapi_changelog.md

+### Changelog for internal API (ui-api)
+
+### 2.0.0
+
+* Modify how `call_info` on a transaction is conveyed. New format:
+
+```
+{
+  "jsonrpc": "2.0",
+  "id": 2,
+  "method": "ApproveTx",
+  "params": [
+    {
+      "transaction": {
+        "from": "0x82A2A876D39022B3019932D30Cd9c97ad5616813",
+        "to": "0x07a565b7ed7d7a678680a4c162885bedbb695fe0",
+        "gas": "0x333",
+        "gasPrice": "0x123",
+        "value": "0x10",
+        "nonce": "0x0",
+        "data": "0x4401a6e40000000000000000000000000000000000000000000000000000000000000012",
+        "input": null
+      },
+      "call_info": [
+        {
+          "type": "WARNING",
+          "message": "Invalid checksum on to-address"
+        },
+        {
+          "type": "WARNING",
+          "message": "Tx contains data, but provided ABI signature could not be matched: Did not match: test (0 matches)"
+        }
+      ],
+      "meta": {
+        "remote": "127.0.0.1:54286",
+        "local": "localhost:8550",
+        "scheme": "HTTP/1.1"
+      }
+    }
+  ]
+}
+```
+
+#### 1.2.0
+
+* Add `OnStartup` method, to provide the UI with information about what API version
+the signer uses (both internal and external) aswell as build-info and external api.
+
+Example call:
+```json
+{
+  "jsonrpc": "2.0",
+  "id": 1,
+  "method": "OnSignerStartup",
+  "params": [
+    {
+      "info": {
+        "extapi_http": "http://localhost:8550",
+        "extapi_ipc": null,
+        "extapi_version": "2.0.0",
+        "intapi_version": "1.2.0"
+      }
+    }
+  ]
+}
+```
+
+#### 1.1.0
+
+* Add `OnApproved` method
+
+#### 1.0.0
+
+Initial release.
+
+### Versioning
+
+The API uses [semantic versioning](https://semver.org/).
+
+TLDR; Given a version number MAJOR.MINOR.PATCH, increment the:
+
+* MAJOR version when you make incompatible API changes,
+* MINOR version when you add functionality in a backwards-compatible manner, and
+* PATCH version when you make backwards-compatible bug fixes.
+
+Additional labels for pre-release and build metadata are available as extensions to the MAJOR.MINOR.PATCH format.

cmd/clef/pythonsigner.py

+import os,sys, subprocess
+from tinyrpc.transports import ServerTransport
+from tinyrpc.protocols.jsonrpc import JSONRPCProtocol
+from tinyrpc.dispatch import public,RPCDispatcher
+from tinyrpc.server import RPCServer
+
+""" This is a POC example of how to write a custom UI for Clef. The UI starts the
+clef process with the '--stdio-ui' option, and communicates with clef using standard input / output.
+
+The standard input/output is a relatively secure way to communicate, as it does not require opening any ports
+or IPC files. Needless to say, it does not protect against memory inspection mechanisms where an attacker
+can access process memory."""
+
+try:
+    import urllib.parse as urlparse
+except ImportError:
+    import urllib as urlparse
+
+class StdIOTransport(ServerTransport):
+    """ Uses std input/output for RPC """
+    def receive_message(self):
+        return None, urlparse.unquote(sys.stdin.readline())
+
+    def send_reply(self, context, reply):
+        print(reply)
+
+class PipeTransport(ServerTransport):
+    """ Uses std a pipe for RPC """
+
+    def __init__(self,input, output):
+        self.input = input
+        self.output = output
+
+    def receive_message(self):
+        data = self.input.readline()
+        print(">> {}".format( data))
+        return None, urlparse.unquote(data)
+
+    def send_reply(self, context, reply):
+        print("<< {}".format( reply))
+        self.output.write(reply)
+        self.output.write("\n")
+
+class StdIOHandler():
+
+    def __init__(self):
+        pass
+
+    @public
+    def ApproveTx(self,req):
+        """
+        Example request:
+        {
+            "jsonrpc": "2.0",
+            "method": "ApproveTx",
+            "params": [{
+                "transaction": {
+                    "to": "0xae967917c465db8578ca9024c205720b1a3651A9",
+                    "gas": "0x333",
+                    "gasPrice": "0x123",
+                    "value": "0x10",
+                    "data": "0xd7a5865800000000000000000000000000000000000000000000000000000000000000ff",
+                    "nonce": "0x0"
+                },
+                "from": "0xAe967917c465db8578ca9024c205720b1a3651A9",
+                "call_info": "Warning! Could not validate ABI-data against calldata\nSupplied ABI spec does not contain method signature in data: 0xd7a58658",
+                "meta": {
+                    "remote": "127.0.0.1:34572",
+                    "local": "localhost:8550",
+                    "scheme": "HTTP/1.1"
+                }
+            }],
+            "id": 1
+        }
+
+        :param transaction: transaction info
+        :param call_info: info abou the call, e.g. if ABI info could not be
+        :param meta: metadata about the request, e.g. where the call comes from
+        :return: 
+        """
+        transaction = req.get('transaction')
+        _from       = req.get('from')
+        call_info   = req.get('call_info')
+        meta        = req.get('meta')
+
+        return {
+            "approved" : False,
+            #"transaction" : transaction,
+  #          "from" : _from,
+#            "password" : None,
+        }
+
+    @public
+    def ApproveSignData(self, req):
+        """ Example request
+
+        """
+        return {"approved": False, "password" : None}
+
+    @public
+    def ApproveExport(self, req):
+        """ Example request
+
+        """
+        return {"approved" : False}
+
+    @public
+    def ApproveImport(self, req):
+        """ Example request
+
+        """
+        return { "approved" : False, "old_password": "", "new_password": ""}
+
+    @public
+    def ApproveListing(self, req):
+        """ Example request
+
+        """
+        return {'accounts': []}
+
+    @public
+    def ApproveNewAccount(self, req):
+        """
+        Example request
+
+        :return:
+        """
+        return {"approved": False,
+                #"password": ""
+                }
+
+    @public
+    def ShowError(self,message = {}):
+        """
+        Example request:
+
+        {"jsonrpc":"2.0","method":"ShowInfo","params":{"message":"Testing 'ShowError'"},"id":1}
+
+        :param message: to show
+        :return: nothing
+        """
+        if 'text' in message.keys():
+            sys.stderr.write("Error: {}\n".format( message['text']))
+        return
+
+    @public
+    def ShowInfo(self,message = {}):
+        """
+        Example request
+        {"jsonrpc":"2.0","method":"ShowInfo","params":{"message":"Testing 'ShowInfo'"},"id":0}
+
+        :param message: to display
+        :return:nothing
+        """
+
+        if 'text' in message.keys():
+            sys.stdout.write("Error: {}\n".format( message['text']))
+        return
+
+def main(args):
+
+    cmd = ["./clef", "--stdio-ui"]
+    if len(args) > 0 and args[0] == "test":
+        cmd.extend(["--stdio-ui-test"])
+    print("cmd: {}".format(" ".join(cmd)))
+    dispatcher = RPCDispatcher()
+    dispatcher.register_instance(StdIOHandler(), '')
+    # line buffered
+    p = subprocess.Popen(cmd, bufsize=1, universal_newlines=True, stdin=subprocess.PIPE, stdout=subprocess.PIPE)
+
+    rpc_server = RPCServer(
+        PipeTransport(p.stdout, p.stdin),
+        JSONRPCProtocol(),
+        dispatcher
+    )
+    rpc_server.serve_forever()
+
+if __name__ == '__main__':
+    main(sys.argv[1:])

cmd/clef/rules.md

+# Rules
+
+The `signer` binary contains a ruleset engine, implemented with [OttoVM](https://github.com/robertkrimen/otto)
+
+It enables usecases like the following:
+
+* I want to auto-approve transactions with contract `CasinoDapp`, with up to `0.05 ether` in value to maximum `1 ether` per 24h period
+* I want to auto-approve transaction to contract `EthAlarmClock` with `data`=`0xdeadbeef`, if `value=0`, `gas < 44k` and `gasPrice < 40Gwei`
+
+The two main features that are required for this to work well are;
+
+1. Rule Implementation: how to create, manage and interpret rules in a flexible but secure manner
+2. Credential managements and credentials; how to provide auto-unlock without exposing keys unnecessarily.
+
+The section below deals with both of them
+
+## Rule Implementation
+
+A ruleset file is implemented as a `js` file. Under the hood, the ruleset-engine is a `SignerUI`, implementing the same methods as the `json-rpc` methods
+defined in the UI protocol. Example:
+
+```javascript
+
+function asBig(str){
+    if(str.slice(0,2) == "0x"){ return new BigNumber(str.slice(2),16)}
+    return new BigNumber(str)
+}
+
+// Approve transactions to a certain contract if value is below a certain limit
+function ApproveTx(req){
+
+    var limit = big.Newint("0xb1a2bc2ec50000")
+	var value = asBig(req.transaction.value);
+
+	if(req.transaction.to.toLowerCase()=="0xae967917c465db8578ca9024c205720b1a3651a9")
+	    && value.lt(limit) ){
+	    return "Approve"
+	 }
+    // If we return "Reject", it will be rejected.
+    // By not returning anything, it will be passed to the next UI, for manual processing
+}
+
+//Approve listings if request made from IPC
+function ApproveListing(req){
+    if (req.metadata.scheme == "ipc"){ return "Approve"}
+}
+
+```
+
+Whenever the external API is called (and the ruleset is enabled), the `signer` calls the UI, which is an instance of a ruleset-engine. The ruleset-engine
+invokes the corresponding method. In doing so, there are three possible outcomes:
+
+1. JS returns "Approve"
+  * Auto-approve request
+2. JS returns "Reject"
+  * Auto-reject request
+3. Error occurs, or something else is returned
+  * Pass on to `next` ui: the regular UI channel.
+
+A more advanced example can be found below, "Example 1: ruleset for a rate-limited window", using `storage` to `Put` and `Get` `string`s by key.
+
+* At the time of writing, storage only exists as an ephemeral unencrypted implementation, to be used during testing.
+
+### Things to note
+
+The Otto vm has a few [caveats](https://github.com/robertkrimen/otto):
+
+* "use strict" will parse, but does nothing.
+* The regular expression engine (re2/regexp) is not fully compatible with the ECMA5 specification.
+* Otto targets ES5. ES6 features (eg: Typed Arrays) are not supported.
+
+Additionally, a few more have been added
+
+* The rule execution cannot load external javascript files.
+* The only preloaded libary is [`bignumber.js`](https://github.com/MikeMcl/bignumber.js) version `2.0.3`. This one is fairly old, and is not aligned with the documentation at the github repository.
+* Each invocation is made in a fresh virtual machine. This means that you cannot store data in global variables between invocations. This is a deliberate choice -- if you want to store data, use the disk-backed `storage`, since rules should not rely on ephemeral data.
+* Javascript API parameters are _always_ an object. This is also a design choice, to ensure that parameters are accessed by _key_ and not by order. This is to prevent mistakes due to missing parameters or parameter changes.
+* The JS engine has access to `storage` and `console`.
+
+#### Security considerations
+
+##### Security of ruleset
+
+Some security precautions can be made, such as:
+
+* Never load `ruleset.js` unless the file is `readonly` (`r-??-??-?`). If the user wishes to modify the ruleset, he must make it writeable and then set back to readonly.
+  * This is to prevent attacks where files are dropped on the users disk.
+* Since we're going to have to have some form of secure storage (not defined in this section), we could also store the `sha3` of the `ruleset.js` file in there.
+  * If the user wishes to modify the ruleset, he'd then have to perform e.g. `signer --attest /path/to/ruleset --credential <creds>`
+
+##### Security of implementation
+
+The drawbacks of this very flexible solution is that the `signer` needs to contain a javascript engine. This is pretty simple to implement, since it's already
+implemented for `geth`. There are no known security vulnerabilities in, nor have we had any security-problems with it so far.
+
+The javascript engine would be an added attack surface; but if the validation of `rulesets` is made good (with hash-based attestation), the actual javascript cannot be considered
+an attack surface -- if an attacker can control the ruleset, a much simpler attack would be to implement an "always-approve" rule instead of exploiting the js vm. The only benefit
+to be gained from attacking the actual `signer` process from the `js` side would be if it could somehow extract cryptographic keys from memory.
+
+##### Security in usability
+
+Javascript is flexible, but also easy to get wrong, especially when users assume that `js` can handle large integers natively. Typical errors
+include trying to multiply `gasCost` with `gas` without using `bigint`:s.
+
+It's unclear whether any other DSL could be more secure; since there's always the possibility of erroneously implementing a rule.
+
+
+## Credential management
+
+The ability to auto-approve transaction means that the signer needs to have necessary credentials to decrypt keyfiles. These passwords are hereafter called `ksp` (keystore pass).
+
+### Example implementation
+
+Upon startup of the signer, the signer is given a switch: `--seed <path/to/masterseed>`
+The `seed` contains a blob of bytes, which is the master seed for the `signer`.
+
+The `signer` uses the `seed` to:
+
+* Generate the `path` where the settings are stored.
+  * `./settings/1df094eb-c2b1-4689-90dd-790046d38025/vault.dat`
+  * `./settings/1df094eb-c2b1-4689-90dd-790046d38025/rules.js`
+* Generate the encryption password for `vault.dat`.
+
+The `vault.dat` would be an encrypted container storing the following information:
+
+* `ksp` entries
+* `sha256` hash of `rules.js`
+* Information about pair:ed callers (not yet specified)
+
+### Security considerations
+
+This would leave it up to the user to ensure that the `path/to/masterseed` is handled in a secure way. It's difficult to get around this, although one could
+imagine leveraging OS-level keychains where supported. The setup is however in general similar to how ssh-keys are  stored in `.ssh/`.
+
+
+# Implementation status
+
+This is now implemented (with ephemeral non-encrypted storage for now, so not yet enabled).
+
+## Example 1: ruleset for a rate-limited window
+
+
+```javascript
+
+	function big(str){
+		if(str.slice(0,2) == "0x"){ return new BigNumber(str.slice(2),16)}
+		return new BigNumber(str)
+	}
+
+	// Time window: 1 week
+	var window = 1000* 3600*24*7;
+
+	// Limit : 1 ether
+	var limit = new BigNumber("1e18");
+
+	function isLimitOk(transaction){
+		var value = big(transaction.value)
+		// Start of our window function
+		var windowstart = new Date().getTime() - window;
+
+		var txs = [];
+		var stored = storage.Get('txs');
+
+		if(stored != ""){
+			txs = JSON.parse(stored)
+		}
+		// First, remove all that have passed out of the time-window
+		var newtxs = txs.filter(function(tx){return tx.tstamp > windowstart});
+		console.log(txs, newtxs.length);
+
+		// Secondly, aggregate the current sum
+		sum = new BigNumber(0)
+
+		sum = newtxs.reduce(function(agg, tx){ return big(tx.value).plus(agg)}, sum);
+		console.log("ApproveTx > Sum so far", sum);
+		console.log("ApproveTx > Requested", value.toNumber());
+
+		// Would we exceed weekly limit ?
+		return sum.plus(value).lt(limit)
+
+	}
+	function ApproveTx(r){
+		if (isLimitOk(r.transaction)){
+			return "Approve"
+		}
+		return "Nope"
+	}
+
+	/**
+	* OnApprovedTx(str) is called when a transaction has been approved and signed. The parameter
+ 	* 'response_str' contains the return value that will be sent to the external caller.
+	* The return value from this method is ignore - the reason for having this callback is to allow the
+	* ruleset to keep track of approved transactions.
+	*
+	* When implementing rate-limited rules, this callback should be used.
+	* If a rule responds with neither 'Approve' nor 'Reject' - the tx goes to manual processing. If the user
+	* then accepts the transaction, this method will be called.
+	*
+	* TLDR; Use this method to keep track of signed transactions, instead of using the data in ApproveTx.
+	*/
+ 	function OnApprovedTx(resp){
+		var value = big(resp.tx.value)
+		var txs = []
+		// Load stored transactions
+		var stored = storage.Get('txs');
+		if(stored != ""){
+			txs = JSON.parse(stored)
+		}
+		// Add this to the storage
+		txs.push({tstamp: new Date().getTime(), value: value});
+		storage.Put("txs", JSON.stringify(txs));
+	}
+
+```
+
+## Example 2: allow destination
+
+```javascript
+
+	function ApproveTx(r){
+		if(r.transaction.from.toLowerCase()=="0x0000000000000000000000000000000000001337"){ return "Approve"}
+		if(r.transaction.from.toLowerCase()=="0x000000000000000000000000000000000000dead"){ return "Reject"}
+		// Otherwise goes to manual processing
+	}
+
+```
+
+## Example 3: Allow listing
+
+```javascript
+
+    function ApproveListing(){
+        return "Approve"
+    }
+
+```
\ No newline at end of file

cmd/clef/tutorial.md

+## Initializing the signer
+
+First, initialize the master seed.
+
+```text
+#./signer init
+
+WARNING!
+
+The signer is alpha software, and not yet publically released. This software has _not_ been audited, and there
+are no guarantees about the workings of this software. It may contain severe flaws. You should not use this software
+unless you agree to take full responsibility for doing so, and know what you are doing.
+
+TLDR; THIS IS NOT PRODUCTION-READY SOFTWARE!
+
+
+Enter 'ok' to proceed:
+>ok
+A master seed has been generated into /home/martin/.signer/secrets.dat
+
+This is required to be able to store credentials, such as :
+* Passwords for keystores (used by rule engine)
+* Storage for javascript rules
+* Hash of rule-file
+
+You should treat that file with utmost secrecy, and make a backup of it.
+NOTE: This file does not contain your accounts. Those need to be backed up separately!
+```
+
+(for readability purposes, we'll remove the WARNING printout in the rest of this document)
+
+## Creating rules
+
+Now, you can create a rule-file.
+
+```javascript
+function ApproveListing(){
+    return "Approve"
+}
+```
+Get the `sha256` hash....
+```text
+#sha256sum rules.js
+6c21d1737429d6d4f2e55146da0797782f3c0a0355227f19d702df377c165d72  rules.js
+```
+...And then `attest` the file:
+```text
+#./signer attest 6c21d1737429d6d4f2e55146da0797782f3c0a0355227f19d702df377c165d72
+
+INFO [02-21|12:14:38] Ruleset attestation updated              sha256=6c21d1737429d6d4f2e55146da0797782f3c0a0355227f19d702df377c165d72
+```
+At this point, we then start the signer with the rule-file:
+
+```text
+#./signer --rules rules.json
+
+INFO [02-21|12:15:18] Using CLI as UI-channel
+INFO [02-21|12:15:18] Loaded 4byte db                          signatures=5509 file=./4byte.json
+INFO [02-21|12:15:18] Could not load rulefile, rules not enabled file=rulefile
+DEBUG[02-21|12:15:18] FS scan times                            list=35.335µs set=5.536µs diff=5.073µs
+DEBUG[02-21|12:15:18] Ledger support enabled
+DEBUG[02-21|12:15:18] Trezor support enabled
+INFO [02-21|12:15:18] Audit logs configured                    file=audit.log
+INFO [02-21|12:15:18] HTTP endpoint opened                     url=http://localhost:8550
+------- Signer info -------
+* extapi_http : http://localhost:8550
+* extapi_ipc : <nil>
+* extapi_version : 2.0.0
+* intapi_version : 1.2.0
+
+```
+
+Any list-requests will now be auto-approved by our rule-file.
+
+## Under the hood
+
+While doing the operations above, these files have been created:
+
+```text
+#ls -laR ~/.signer/
+/home/martin/.signer/:
+total 16
+drwx------  3 martin martin 4096 feb 21 12:14 .
+drwxr-xr-x 71 martin martin 4096 feb 21 12:12 ..
+drwx------  2 martin martin 4096 feb 21 12:14 43f73718397aa54d1b22
+-rwx------  1 martin martin  256 feb 21 12:12 secrets.dat
+
+/home/martin/.signer/43f73718397aa54d1b22:
+total 12
+drwx------ 2 martin martin 4096 feb 21 12:14 .
+drwx------ 3 martin martin 4096 feb 21 12:14 ..
+-rw------- 1 martin martin  159 feb 21 12:14 config.json
+
+#cat /home/martin/.signer/43f73718397aa54d1b22/config.json
+{"ruleset_sha256":{"iv":"6v4W4tfJxj3zZFbl","c":"6dt5RTDiTq93yh1qDEjpsat/tsKG7cb+vr3sza26IPL2fvsQ6ZoqFx++CPUa8yy6fD9Bbq41L01ehkKHTG3pOAeqTW6zc/+t0wv3AB6xPmU="}}
+
+```
+
+In `~/.signer`, the `secrets.dat` file was created, containing the `master_seed`.
+The `master_seed` was then used to derive a few other things:
+
+- `vault_location` : in this case `43f73718397aa54d1b22` .
+   - Thus, if you use a different `master_seed`, another `vault_location` will be used that does not conflict with each other.
+   - Example: `signer --signersecret /path/to/afile ...`
+- `config.json` which is the encrypted key/value storage for configuration data, containing the key `ruleset_sha256`.
+
+
+## Adding credentials
+
+In order to make more useful rules; sign transactions, the signer needs access to the passwords needed to unlock keystores.
+
+```text
+#./signer addpw 0x694267f14675d7e1b9494fd8d72fefe1755710fa test
+
+INFO [02-21|13:43:21] Credential store updated                 key=0x694267f14675d7e1b9494fd8d72fefe1755710fa
+```
+## More advanced rules
+
+Now let's update the rules to make use of credentials
+
+```javascript
+function ApproveListing(){
+    return "Approve"
+}
+function ApproveSignData(r){
+    if( r.address.toLowerCase() == "0x694267f14675d7e1b9494fd8d72fefe1755710fa")
+    {
+        if(r.message.indexOf("bazonk") >= 0){
+            return "Approve"
+        }
+        return "Reject"
+    }
+    // Otherwise goes to manual processing
+}
+
+```
+In this example,
+* any requests to sign data with the account `0x694...` will be
+    * auto-approved if the message contains with `bazonk`,
+    * and auto-rejected if it does not.
+    * Any other signing-requests will be passed along for manual approve/reject.
+
+..attest the new file
+```text
+#sha256sum rules.js
+2a0cb661dacfc804b6e95d935d813fd17c0997a7170e4092ffbc34ca976acd9f  rules.js
+
+#./signer attest 2a0cb661dacfc804b6e95d935d813fd17c0997a7170e4092ffbc34ca976acd9f
+
+INFO [02-21|14:36:30] Ruleset attestation updated              sha256=2a0cb661dacfc804b6e95d935d813fd17c0997a7170e4092ffbc34ca976acd9f
+```
+
+And start the signer:
+
+```
+#./signer --rules rules.js
+
+INFO [02-21|14:41:56] Using CLI as UI-channel
+INFO [02-21|14:41:56] Loaded 4byte db                          signatures=5509 file=./4byte.json
+INFO [02-21|14:41:56] Rule engine configured                   file=rules.js
+DEBUG[02-21|14:41:56] FS scan times                            list=34.607µs set=4.509µs diff=4.87µs
+DEBUG[02-21|14:41:56] Ledger support enabled
+DEBUG[02-21|14:41:56] Trezor support enabled
+INFO [02-21|14:41:56] Audit logs configured                    file=audit.log
+INFO [02-21|14:41:56] HTTP endpoint opened                     url=http://localhost:8550
+------- Signer info -------
+* extapi_version : 2.0.0
+* intapi_version : 1.2.0
+* extapi_http : http://localhost:8550
+* extapi_ipc : <nil>
+INFO [02-21|14:41:56] error occurred during execution          error="ReferenceError: 'OnSignerStartup' is not defined"
+```
+And then test signing, once with `bazonk` and once without:
+
+```
+#curl -H "Content-Type: application/json" -X POST --data "{\"jsonrpc\":\"2.0\",\"method\":\"account_sign\",\"params\":[\"0x694267f14675d7e1b9494fd8d72fefe1755710fa\",\"0x$(xxd -pu <<< '  bazonk baz gaz')\"],\"id\":67}" http://localhost:8550/
+{"jsonrpc":"2.0","id":67,"result":"0x93e6161840c3ae1efc26dc68dedab6e8fc233bb3fefa1b4645dbf6609b93dace160572ea4ab33240256bb6d3dadb60dcd9c515d6374d3cf614ee897408d41d541c"}
+
+#curl -H "Content-Type: application/json" -X POST --data "{\"jsonrpc\":\"2.0\",\"method\":\"account_sign\",\"params\":[\"0x694267f14675d7e1b9494fd8d72fefe1755710fa\",\"0x$(xxd -pu <<< '  bonk baz gaz')\"],\"id\":67}" http://localhost:8550/
+{"jsonrpc":"2.0","id":67,"error":{"code":-32000,"message":"Request denied"}}
+
+```
+
+Meanwhile, in the signer output:
+```text
+INFO [02-21|14:42:41] Op approved
+INFO [02-21|14:42:56] Op rejected
+```
+
+The signer also stores all traffic over the external API in a log file. The last 4 lines shows the two requests and their responses:
+
+```text
+#tail audit.log -n 4
+t=2018-02-21T14:42:41+0100 lvl=info msg=Sign       api=signer type=request  metadata="{\"remote\":\"127.0.0.1:49706\",\"local\":\"localhost:8550\",\"scheme\":\"HTTP/1.1\"}" addr="0x694267f14675d7e1b9494fd8d72fefe1755710fa [chksum INVALID]" data=202062617a6f6e6b2062617a2067617a0a
+t=2018-02-21T14:42:42+0100 lvl=info msg=Sign       api=signer type=response data=93e6161840c3ae1efc26dc68dedab6e8fc233bb3fefa1b4645dbf6609b93dace160572ea4ab33240256bb6d3dadb60dcd9c515d6374d3cf614ee897408d41d541c error=nil
+t=2018-02-21T14:42:56+0100 lvl=info msg=Sign       api=signer type=request  metadata="{\"remote\":\"127.0.0.1:49708\",\"local\":\"localhost:8550\",\"scheme\":\"HTTP/1.1\"}" addr="0x694267f14675d7e1b9494fd8d72fefe1755710fa [chksum INVALID]" data=2020626f6e6b2062617a2067617a0a
+t=2018-02-21T14:42:56+0100 lvl=info msg=Sign       api=signer type=response data=                                                                                                                                   error="Request denied"
+```

common/types.go

@@ -23,8 +23,10 @@ import (
 	"math/rand"
 	"reflect"
 
+	"encoding/json"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/crypto/sha3"
+	"strings"
 )
 
 const (
@@ -238,3 +240,63 @@ func (a *UnprefixedAddress) UnmarshalText(input []byte) error {
 func (a UnprefixedAddress) MarshalText() ([]byte, error) {
 	return []byte(hex.EncodeToString(a[:])), nil
 }
+
+// MixedcaseAddress retains the original string, which may or may not be
+// correctly checksummed
+type MixedcaseAddress struct {
+	addr     Address
+	original string
+}
+
+// NewMixedcaseAddress constructor (mainly for testing)
+func NewMixedcaseAddress(addr Address) MixedcaseAddress {
+	return MixedcaseAddress{addr: addr, original: addr.Hex()}
+}
+
+// NewMixedcaseAddressFromString is mainly meant for unit-testing
+func NewMixedcaseAddressFromString(hexaddr string) (*MixedcaseAddress, error) {
+	if !IsHexAddress(hexaddr) {
+		return nil, fmt.Errorf("Invalid address")
+	}
+	a := FromHex(hexaddr)
+	return &MixedcaseAddress{addr: BytesToAddress(a), original: hexaddr}, nil
+}
+
+// UnmarshalJSON parses MixedcaseAddress
+func (ma *MixedcaseAddress) UnmarshalJSON(input []byte) error {
+	if err := hexutil.UnmarshalFixedJSON(addressT, input, ma.addr[:]); err != nil {
+		return err
+	}
+	return json.Unmarshal(input, &ma.original)
+}
+
+// MarshalJSON marshals the original value
+func (ma *MixedcaseAddress) MarshalJSON() ([]byte, error) {
+	if strings.HasPrefix(ma.original, "0x") || strings.HasPrefix(ma.original, "0X") {
+		return json.Marshal(fmt.Sprintf("0x%s", ma.original[2:]))
+	}
+	return json.Marshal(fmt.Sprintf("0x%s", ma.original))
+}
+
+// Address returns the address
+func (ma *MixedcaseAddress) Address() Address {
+	return ma.addr
+}
+
+// String implements fmt.Stringer
+func (ma *MixedcaseAddress) String() string {
+	if ma.ValidChecksum() {
+		return fmt.Sprintf("%s [chksum ok]", ma.original)
+	}
+	return fmt.Sprintf("%s [chksum INVALID]", ma.original)
+}
+
+// ValidChecksum returns true if the address has valid checksum
+func (ma *MixedcaseAddress) ValidChecksum() bool {
+	return ma.original == ma.addr.Hex()
+}
+
+// Original returns the mixed-case input string
+func (ma *MixedcaseAddress) Original() string {
+	return ma.original
+}

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)
+		}
+
+	}
+
+}

node/node.go

@@ -306,47 +306,23 @@ func (n *Node) startIPC(apis []rpc.API) error {
 	// Short circuit if the IPC endpoint isn't being exposed
 	if n.ipcEndpoint == "" {
 		return nil
+
 	}
-	// Register all the APIs exposed by the services
-	handler := rpc.NewServer()
-	for _, api := range apis {
-		if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
-			return err
-		}
-		n.log.Debug("IPC registered", "service", api.Service, "namespace", api.Namespace)
-	}
-	// All APIs registered, start the IPC listener
-	var (
-		listener net.Listener
-		err      error
-	)
-	if listener, err = rpc.CreateIPCListener(n.ipcEndpoint); err != nil {
-		return err
+	isClosed := func() bool {
+		n.lock.RLock()
+		defer n.lock.RUnlock()
+		return n.ipcListener == nil
 	}
-	go func() {
-		n.log.Info("IPC endpoint opened", "url", n.ipcEndpoint)
 
-		for {
-			conn, err := listener.Accept()
+	listener, handler, err := rpc.StartIPCEndpoint(isClosed, n.ipcEndpoint, apis)
 	if err != nil {
-				// Terminate if the listener was closed
-				n.lock.RLock()
-				closed := n.ipcListener == nil
-				n.lock.RUnlock()
-				if closed {
-					return
-				}
-				// Not closed, just some error; report and continue
-				n.log.Error("IPC accept failed", "err", err)
-				continue
-			}
-			go handler.ServeCodec(rpc.NewJSONCodec(conn), rpc.OptionMethodInvocation|rpc.OptionSubscriptions)
+		return err
 	}
-	}()
+
 	// All listeners booted successfully
 	n.ipcListener = listener
 	n.ipcHandler = handler
-
+	n.log.Info("IPC endpoint opened", "url", n.ipcEndpoint)
 	return nil
 }
 
@@ -370,30 +346,10 @@ func (n *Node) startHTTP(endpoint string, apis []rpc.API, modules []string, cors
 	if endpoint == "" {
 		return nil
 	}
-	// Generate the whitelist based on the allowed modules
-	whitelist := make(map[string]bool)
-	for _, module := range modules {
-		whitelist[module] = true
-	}
-	// Register all the APIs exposed by the services
-	handler := rpc.NewServer()
-	for _, api := range apis {
-		if whitelist[api.Namespace] || (len(whitelist) == 0 && api.Public) {
-			if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
-				return err
-			}
-			n.log.Debug("HTTP registered", "service", api.Service, "namespace", api.Namespace)
-		}
-	}
-	// All APIs registered, start the HTTP listener
-	var (
-		listener net.Listener
-		err      error
-	)
-	if listener, err = net.Listen("tcp", endpoint); err != nil {
+	listener, handler, err := rpc.StartHTTPEndpoint(endpoint, apis, modules, cors, vhosts)
+	if err != nil {
 		return err
 	}
-	go rpc.NewHTTPServer(cors, vhosts, handler).Serve(listener)
 	n.log.Info("HTTP endpoint opened", "url", fmt.Sprintf("http://%s", endpoint), "cors", strings.Join(cors, ","), "vhosts", strings.Join(vhosts, ","))
 	// All listeners booted successfully
 	n.httpEndpoint = endpoint
@@ -423,32 +379,11 @@ func (n *Node) startWS(endpoint string, apis []rpc.API, modules []string, wsOrig
 	if endpoint == "" {
 		return nil
 	}
-	// Generate the whitelist based on the allowed modules
-	whitelist := make(map[string]bool)
-	for _, module := range modules {
-		whitelist[module] = true
-	}
-	// Register all the APIs exposed by the services
-	handler := rpc.NewServer()
-	for _, api := range apis {
-		if exposeAll || whitelist[api.Namespace] || (len(whitelist) == 0 && api.Public) {
-			if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
-				return err
-			}
-			n.log.Debug("WebSocket registered", "service", api.Service, "namespace", api.Namespace)
-		}
-	}
-	// All APIs registered, start the HTTP listener
-	var (
-		listener net.Listener
-		err      error
-	)
-	if listener, err = net.Listen("tcp", endpoint); err != nil {
+	listener, handler, err := rpc.StartWSEndpoint(endpoint, apis, modules, wsOrigins, exposeAll)
+	if err != nil {
 		return err
 	}
-	go rpc.NewWSServer(wsOrigins, handler).Serve(listener)
 	n.log.Info("WebSocket endpoint opened", "url", fmt.Sprintf("ws://%s", listener.Addr()))
-
 	// All listeners booted successfully
 	n.wsEndpoint = endpoint
 	n.wsListener = listener

rpc/client.go

@@ -33,6 +33,7 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/log"
+	"os"
 )
 
 var (
@@ -171,6 +172,8 @@ func DialContext(ctx context.Context, rawurl string) (*Client, error) {
 		return DialHTTP(rawurl)
 	case "ws", "wss":
 		return DialWebsocket(ctx, rawurl, "")
+	case "stdio":
+		return DialStdIO(ctx)
 	case "":
 		return DialIPC(ctx, rawurl)
 	default:
@@ -178,13 +181,51 @@ func DialContext(ctx context.Context, rawurl string) (*Client, error) {
 	}
 }
 
+type StdIOConn struct{}
+
+func (io StdIOConn) Read(b []byte) (n int, err error) {
+	return os.Stdin.Read(b)
+}
+
+func (io StdIOConn) Write(b []byte) (n int, err error) {
+	return os.Stdout.Write(b)
+}
+
+func (io StdIOConn) Close() error {
+	return nil
+}
+
+func (io StdIOConn) LocalAddr() net.Addr {
+	return &net.UnixAddr{Name: "stdio", Net: "stdio"}
+}
+
+func (io StdIOConn) RemoteAddr() net.Addr {
+	return &net.UnixAddr{Name: "stdio", Net: "stdio"}
+}
+
+func (io StdIOConn) SetDeadline(t time.Time) error {
+	return &net.OpError{Op: "set", Net: "stdio", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
+}
+
+func (io StdIOConn) SetReadDeadline(t time.Time) error {
+	return &net.OpError{Op: "set", Net: "stdio", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
+}
+
+func (io StdIOConn) SetWriteDeadline(t time.Time) error {
+	return &net.OpError{Op: "set", Net: "stdio", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
+}
+func DialStdIO(ctx context.Context) (*Client, error) {
+	return newClient(ctx, func(_ context.Context) (net.Conn, error) {
+		return StdIOConn{}, nil
+	})
+}
+
 func newClient(initctx context.Context, connectFunc func(context.Context) (net.Conn, error)) (*Client, error) {
 	conn, err := connectFunc(initctx)
 	if err != nil {
 		return nil, err
 	}
 	_, isHTTP := conn.(*httpConn)
-
 	c := &Client{
 		writeConn:   conn,
 		isHTTP:      isHTTP,
@@ -524,13 +565,13 @@ func (c *Client) dispatch(conn net.Conn) {
 			}
 
 		case err := <-c.readErr:
-			log.Debug(fmt.Sprintf("<-readErr: %v", err))
+			log.Debug("<-readErr", "err", err)
 			c.closeRequestOps(err)
 			conn.Close()
 			reading = false
 
 		case newconn := <-c.reconnected:
-			log.Debug(fmt.Sprintf("<-reconnected: (reading=%t) %v", reading, conn.RemoteAddr()))
+			log.Debug("<-reconnected", "reading", reading, "remote", conn.RemoteAddr())
 			if reading {
 				// Wait for the previous read loop to exit. This is a rare case.
 				conn.Close()
@@ -587,7 +628,7 @@ func (c *Client) closeRequestOps(err error) {
 
 func (c *Client) handleNotification(msg *jsonrpcMessage) {
 	if !strings.HasSuffix(msg.Method, notificationMethodSuffix) {
-		log.Debug(fmt.Sprint("dropping non-subscription message: ", msg))
+		log.Debug("dropping non-subscription message", "msg", msg)
 		return
 	}
 	var subResult struct {
@@ -595,7 +636,7 @@ func (c *Client) handleNotification(msg *jsonrpcMessage) {
 		Result json.RawMessage `json:"result"`
 	}
 	if err := json.Unmarshal(msg.Params, &subResult); err != nil {
-		log.Debug(fmt.Sprint("dropping invalid subscription message: ", msg))
+		log.Debug("dropping invalid subscription message", "msg", msg)
 		return
 	}
 	if c.subs[subResult.ID] != nil {
@@ -606,7 +647,7 @@ func (c *Client) handleNotification(msg *jsonrpcMessage) {
 func (c *Client) handleResponse(msg *jsonrpcMessage) {
 	op := c.respWait[string(msg.ID)]
 	if op == nil {
-		log.Debug(fmt.Sprintf("unsolicited response %v", msg))
+		log.Debug("unsolicited response", "msg", msg)
 		return
 	}
 	delete(c.respWait, string(msg.ID))

rpc/endpoints.go

+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package rpc
+
+import (
+	"github.com/ethereum/go-ethereum/log"
+	"net"
+)
+
+// StartHTTPEndpoint starts the HTTP RPC endpoint, configured with cors/vhosts/modules
+func StartHTTPEndpoint(endpoint string, apis []API, modules []string, cors []string, vhosts []string) (net.Listener, *Server, error) {
+	// Generate the whitelist based on the allowed modules
+	whitelist := make(map[string]bool)
+	for _, module := range modules {
+		whitelist[module] = true
+	}
+	// Register all the APIs exposed by the services
+	handler := NewServer()
+	for _, api := range apis {
+		if whitelist[api.Namespace] || (len(whitelist) == 0 && api.Public) {
+			if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
+				return nil, nil, err
+			}
+			log.Debug("HTTP registered", "namespace", api.Namespace)
+		}
+	}
+	// All APIs registered, start the HTTP listener
+	var (
+		listener net.Listener
+		err      error
+	)
+	if listener, err = net.Listen("tcp", endpoint); err != nil {
+		return nil, nil, err
+	}
+	go NewHTTPServer(cors, vhosts, handler).Serve(listener)
+	return listener, handler, err
+}
+
+// StartWSEndpoint starts a websocket endpoint
+func StartWSEndpoint(endpoint string, apis []API, modules []string, wsOrigins []string, exposeAll bool) (net.Listener, *Server, error) {
+
+	// Generate the whitelist based on the allowed modules
+	whitelist := make(map[string]bool)
+	for _, module := range modules {
+		whitelist[module] = true
+	}
+	// Register all the APIs exposed by the services
+	handler := NewServer()
+	for _, api := range apis {
+		if exposeAll || whitelist[api.Namespace] || (len(whitelist) == 0 && api.Public) {
+			if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
+				return nil, nil, err
+			}
+			log.Debug("WebSocket registered", "service", api.Service, "namespace", api.Namespace)
+		}
+	}
+	// All APIs registered, start the HTTP listener
+	var (
+		listener net.Listener
+		err      error
+	)
+	if listener, err = net.Listen("tcp", endpoint); err != nil {
+		return nil, nil, err
+	}
+	go NewWSServer(wsOrigins, handler).Serve(listener)
+	return listener, handler, err
+
+}
+
+// StartIPCEndpoint starts an IPC endpoint
+func StartIPCEndpoint(isClosedFn func() bool, ipcEndpoint string, apis []API) (net.Listener, *Server, error) {
+	// Register all the APIs exposed by the services
+	handler := NewServer()
+	for _, api := range apis {
+		if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
+			return nil, nil, err
+		}
+		log.Debug("IPC registered", "namespace", api.Namespace)
+	}
+	// All APIs registered, start the IPC listener
+	var (
+		listener net.Listener
+		err      error
+	)
+	if listener, err = CreateIPCListener(ipcEndpoint); err != nil {
+		return nil, nil, err
+	}
+	go func() {
+		for {
+			conn, err := listener.Accept()
+			if err != nil {
+				// Terminate if the listener was closed
+				if isClosedFn() {
+					log.Info("IPC closed", "err", err)
+				} else {
+					// Not closed, just some error; report and continue
+					log.Error("IPC accept failed", "err", err)
+				}
+				continue
+			}
+			go handler.ServeCodec(NewJSONCodec(conn), OptionMethodInvocation|OptionSubscriptions)
+		}
+	}()
+
+	return listener, handler, nil
+}

rpc/http.go

@@ -169,12 +169,17 @@ func (srv *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	// All checks passed, create a codec that reads direct from the request body
 	// untilEOF and writes the response to w and order the server to process a
 	// single request.
+	ctx := context.Background()
+	ctx = context.WithValue(ctx, "remote", r.RemoteAddr)
+	ctx = context.WithValue(ctx, "scheme", r.Proto)
+	ctx = context.WithValue(ctx, "local", r.Host)
+
 	body := io.LimitReader(r.Body, maxRequestContentLength)
 	codec := NewJSONCodec(&httpReadWriteNopCloser{body, w})
 	defer codec.Close()
 
 	w.Header().Set("content-type", contentType)
-	srv.ServeSingleRequest(codec, OptionMethodInvocation)
+	srv.ServeSingleRequest(codec, OptionMethodInvocation, ctx)
 }
 
 // validateRequest returns a non-zero response code and error message if the

rpc/server.go

@@ -125,7 +125,7 @@ func (s *Server) RegisterName(name string, rcvr interface{}) error {
 // If singleShot is true it will process a single request, otherwise it will handle
 // requests until the codec returns an error when reading a request (in most cases
 // an EOF). It executes requests in parallel when singleShot is false.
-func (s *Server) serveRequest(codec ServerCodec, singleShot bool, options CodecOption) error {
+func (s *Server) serveRequest(codec ServerCodec, singleShot bool, options CodecOption, ctx context.Context) error {
 	var pend sync.WaitGroup
 
 	defer func() {
@@ -140,7 +140,8 @@ func (s *Server) serveRequest(codec ServerCodec, singleShot bool, options CodecO
 		s.codecsMu.Unlock()
 	}()
 
-	ctx, cancel := context.WithCancel(context.Background())
+	//	ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 
 	// if the codec supports notification include a notifier that callbacks can use
@@ -215,14 +216,14 @@ func (s *Server) serveRequest(codec ServerCodec, singleShot bool, options CodecO
 // stopped. In either case the codec is closed.
 func (s *Server) ServeCodec(codec ServerCodec, options CodecOption) {
 	defer codec.Close()
-	s.serveRequest(codec, false, options)
+	s.serveRequest(codec, false, options, context.Background())
 }
 
 // ServeSingleRequest reads and processes a single RPC request from the given codec. It will not
 // close the codec unless a non-recoverable error has occurred. Note, this method will return after
 // a single request has been processed!
-func (s *Server) ServeSingleRequest(codec ServerCodec, options CodecOption) {
-	s.serveRequest(codec, true, options)
+func (s *Server) ServeSingleRequest(codec ServerCodec, options CodecOption, ctx context.Context) {
+	s.serveRequest(codec, true, options, ctx)
 }
 
 // Stop will stop reading new requests, wait for stopPendingRequestTimeout to allow pending requests to finish,

signer/core/abihelper.go

+// Copyright 2018 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+package core
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/accounts/abi"
+	"github.com/ethereum/go-ethereum/common"
+
+	"bytes"
+	"os"
+	"regexp"
+)
+
+type decodedArgument struct {
+	soltype abi.Argument
+	value   interface{}
+}
+type decodedCallData struct {
+	signature string
+	name      string
+	inputs    []decodedArgument
+}
+
+// String implements stringer interface, tries to use the underlying value-type
+func (arg decodedArgument) String() string {
+	var value string
+	switch arg.value.(type) {
+	case fmt.Stringer:
+		value = arg.value.(fmt.Stringer).String()
+	default:
+		value = fmt.Sprintf("%v", arg.value)
+	}
+	return fmt.Sprintf("%v: %v", arg.soltype.Type.String(), value)
+}
+
+// String implements stringer interface for decodedCallData
+func (cd decodedCallData) String() string {
+	args := make([]string, len(cd.inputs))
+	for i, arg := range cd.inputs {
+		args[i] = arg.String()
+	}
+	return fmt.Sprintf("%s(%s)", cd.name, strings.Join(args, ","))
+}
+
+// parseCallData matches the provided call data against the abi definition,
+// and returns a struct containing the actual go-typed values
+func parseCallData(calldata []byte, abidata string) (*decodedCallData, error) {
+
+	if len(calldata) < 4 {
+		return nil, fmt.Errorf("Invalid ABI-data, incomplete method signature of (%d bytes)", len(calldata))
+	}
+
+	sigdata, argdata := calldata[:4], calldata[4:]
+	if len(argdata)%32 != 0 {
+		return nil, fmt.Errorf("Not ABI-encoded data; length should be a multiple of 32 (was %d)", len(argdata))
+	}
+
+	abispec, err := abi.JSON(strings.NewReader(abidata))
+	if err != nil {
+		return nil, fmt.Errorf("Failed parsing JSON ABI: %v, abidata: %v", err, abidata)
+	}
+
+	method, err := abispec.MethodById(sigdata)
+	if err != nil {
+		return nil, err
+	}
+
+	v, err := method.Inputs.UnpackValues(argdata)
+	if err != nil {
+		return nil, err
+	}
+
+	decoded := decodedCallData{signature: method.Sig(), name: method.Name}
+
+	for n, argument := range method.Inputs {
+		if err != nil {
+			return nil, fmt.Errorf("Failed to decode argument %d (signature %v): %v", n, method.Sig(), err)
+		} else {
+			decodedArg := decodedArgument{
+				soltype: argument,
+				value:   v[n],
+			}
+			decoded.inputs = append(decoded.inputs, decodedArg)
+		}
+	}
+
+	// We're finished decoding the data. At this point, we encode the decoded data to see if it matches with the
+	// original data. If we didn't do that, it would e.g. be possible to stuff extra data into the arguments, which
+	// is not detected by merely decoding the data.
+
+	var (
+		encoded []byte
+	)
+	encoded, err = method.Inputs.PackValues(v)
+
+	if err != nil {
+		return nil, err
+	}
+
+	if !bytes.Equal(encoded, argdata) {
+		was := common.Bytes2Hex(encoded)
+		exp := common.Bytes2Hex(argdata)
+		return nil, fmt.Errorf("WARNING: Supplied data is stuffed with extra data. \nWant %s\nHave %s\nfor method %v", exp, was, method.Sig())
+	}
+	return &decoded, nil
+}
+
+// MethodSelectorToAbi converts a method selector into an ABI struct. The returned data is a valid json string
+// which can be consumed by the standard abi package.
+func MethodSelectorToAbi(selector string) ([]byte, error) {
+
+	re := regexp.MustCompile(`^([^\)]+)\(([a-z0-9,\[\]]*)\)`)
+
+	type fakeArg struct {
+		Type string `json:"type"`
+	}
+	type fakeABI struct {
+		Name   string    `json:"name"`
+		Type   string    `json:"type"`
+		Inputs []fakeArg `json:"inputs"`
+	}
+	groups := re.FindStringSubmatch(selector)
+	if len(groups) != 3 {
+		return nil, fmt.Errorf("Did not match: %v (%v matches)", selector, len(groups))
+	}
+	name := groups[1]
+	args := groups[2]
+	arguments := make([]fakeArg, 0)
+	if len(args) > 0 {
+		for _, arg := range strings.Split(args, ",") {
+			arguments = append(arguments, fakeArg{arg})
+		}
+	}
+	abicheat := fakeABI{
+		name, "function", arguments,
+	}
+	return json.Marshal([]fakeABI{abicheat})
+
+}
+
+type AbiDb struct {
+	db           map[string]string
+	customdb     map[string]string
+	customdbPath string
+}
+
+// NewEmptyAbiDB exists for test purposes
+func NewEmptyAbiDB() (*AbiDb, error) {
+	return &AbiDb{make(map[string]string), make(map[string]string), ""}, nil
+}
+
+// NewAbiDBFromFile loads signature database from file, and
+// errors if the file is not valid json. Does no other validation of contents
+func NewAbiDBFromFile(path string) (*AbiDb, error) {
+	raw, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	db, err := NewEmptyAbiDB()
+	if err != nil {
+		return nil, err
+	}
+	json.Unmarshal(raw, &db.db)
+	return db, nil
+}
+
+// NewAbiDBFromFiles loads both the standard signature database and a custom database. The latter will be used
+// to write new values into if they are submitted via the API
+func NewAbiDBFromFiles(standard, custom string) (*AbiDb, error) {
+
+	db := &AbiDb{make(map[string]string), make(map[string]string), custom}
+	db.customdbPath = custom
+
+	raw, err := ioutil.ReadFile(standard)
+	if err != nil {
+		return nil, err
+	}
+	json.Unmarshal(raw, &db.db)
+	// Custom file may not exist. Will be created during save, if needed
+	if _, err := os.Stat(custom); err == nil {
+		raw, err = ioutil.ReadFile(custom)
+		if err != nil {
+			return nil, err
+		}
+		json.Unmarshal(raw, &db.customdb)
+	}
+
+	return db, nil
+}
+
+// LookupMethodSelector checks the given 4byte-sequence against the known ABI methods.
+// OBS: This method does not validate the match, it's assumed the caller will do so
+func (db *AbiDb) LookupMethodSelector(id []byte) (string, error) {
+	if len(id) < 4 {
+		return "", fmt.Errorf("Expected 4-byte id, got %d", len(id))
+	}
+	sig := common.ToHex(id[:4])
+	if key, exists := db.db[sig]; exists {
+		return key, nil
+	}
+	if key, exists := db.customdb[sig]; exists {
+		return key, nil
+	}
+	return "", fmt.Errorf("Signature %v not found", sig)
+}
+func (db *AbiDb) Size() int {
+	return len(db.db)
+}
+
+// saveCustomAbi saves a signature ephemerally. If custom file is used, also saves to disk
+func (db *AbiDb) saveCustomAbi(selector, signature string) error {
+	db.customdb[signature] = selector
+	if db.customdbPath == "" {
+		return nil //Not an error per se, just not used
+	}
+	d, err := json.Marshal(db.customdb)
+	if err != nil {
+		return err
+	}
+	err = ioutil.WriteFile(db.customdbPath, d, 0600)
+	return err
+}
+
+// Adds a signature to the database, if custom database saving is enabled.
+// OBS: This method does _not_ validate the correctness of the data,
+// it is assumed that the caller has already done so
+func (db *AbiDb) AddSignature(selector string, data []byte) error {
+	if len(data) < 4 {
+		return nil
+	}
+	_, err := db.LookupMethodSelector(data[:4])
+	if err == nil {
+		return nil
+	}
+	sig := common.ToHex(data[:4])
+	return db.saveCustomAbi(selector, sig)
+}

signer/core/api_test.go

+// Copyright 2018 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+//
+package core
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io/ioutil"
+	"math/big"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/ethereum/go-ethereum/accounts/keystore"
+	"github.com/ethereum/go-ethereum/cmd/utils"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/internal/ethapi"
+	"github.com/ethereum/go-ethereum/rlp"
+)
+
+//Used for testing
+type HeadlessUI struct {
+	controller chan string
+}
+
+func (ui *HeadlessUI) OnSignerStartup(info StartupInfo) {
+}
+
+func (ui *HeadlessUI) OnApprovedTx(tx ethapi.SignTransactionResult) {
+	fmt.Printf("OnApproved called")
+}
+
+func (ui *HeadlessUI) ApproveTx(request *SignTxRequest) (SignTxResponse, error) {
+
+	switch <-ui.controller {
+	case "Y":
+		return SignTxResponse{request.Transaction, true, <-ui.controller}, nil
+	case "M": //Modify
+		old := big.Int(request.Transaction.Value)
+		newVal := big.NewInt(0).Add(&old, big.NewInt(1))
+		request.Transaction.Value = hexutil.Big(*newVal)
+		return SignTxResponse{request.Transaction, true, <-ui.controller}, nil
+	default:
+		return SignTxResponse{request.Transaction, false, ""}, nil
+	}
+}
+func (ui *HeadlessUI) ApproveSignData(request *SignDataRequest) (SignDataResponse, error) {
+	if "Y" == <-ui.controller {
+		return SignDataResponse{true, <-ui.controller}, nil
+	}
+	return SignDataResponse{false, ""}, nil
+}
+func (ui *HeadlessUI) ApproveExport(request *ExportRequest) (ExportResponse, error) {
+
+	return ExportResponse{<-ui.controller == "Y"}, nil
+
+}
+func (ui *HeadlessUI) ApproveImport(request *ImportRequest) (ImportResponse, error) {
+
+	if "Y" == <-ui.controller {
+		return ImportResponse{true, <-ui.controller, <-ui.controller}, nil
+	}
+	return ImportResponse{false, "", ""}, nil
+}
+func (ui *HeadlessUI) ApproveListing(request *ListRequest) (ListResponse, error) {
+
+	switch <-ui.controller {
+	case "A":
+		return ListResponse{request.Accounts}, nil
+	case "1":
+		l := make([]Account, 1)
+		l[0] = request.Accounts[1]
+		return ListResponse{l}, nil
+	default:
+		return ListResponse{nil}, nil
+	}
+}
+func (ui *HeadlessUI) ApproveNewAccount(request *NewAccountRequest) (NewAccountResponse, error) {
+
+	if "Y" == <-ui.controller {
+		return NewAccountResponse{true, <-ui.controller}, nil
+	}
+	return NewAccountResponse{false, ""}, nil
+}
+func (ui *HeadlessUI) ShowError(message string) {
+	//stdout is used by communication
+	fmt.Fprint(os.Stderr, message)
+}
+func (ui *HeadlessUI) ShowInfo(message string) {
+	//stdout is used by communication
+	fmt.Fprint(os.Stderr, message)
+}
+
+func tmpDirName(t *testing.T) string {
+	d, err := ioutil.TempDir("", "eth-keystore-test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	d, err = filepath.EvalSymlinks(d)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return d
+}
+
+func setup(t *testing.T) (*SignerAPI, chan string) {
+
+	controller := make(chan string, 10)
+
+	db, err := NewAbiDBFromFile("../../cmd/clef/4byte.json")
+	if err != nil {
+		utils.Fatalf(err.Error())
+	}
+	var (
+		ui  = &HeadlessUI{controller}
+		api = NewSignerAPI(
+			1,
+			tmpDirName(t),
+			true,
+			ui,
+			db,
+			true)
+	)
+	return api, controller
+}
+func createAccount(control chan string, api *SignerAPI, t *testing.T) {
+
+	control <- "Y"
+	control <- "apassword"
+	_, err := api.New(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Some time to allow changes to propagate
+	time.Sleep(250 * time.Millisecond)
+}
+func failCreateAccount(control chan string, api *SignerAPI, t *testing.T) {
+	control <- "N"
+	acc, err := api.New(context.Background())
+	if err != ErrRequestDenied {
+		t.Fatal(err)
+	}
+	if acc.Address != (common.Address{}) {
+		t.Fatal("Empty address should be returned")
+	}
+}
+func list(control chan string, api *SignerAPI, t *testing.T) []Account {
+	control <- "A"
+	list, err := api.List(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	return list
+}
+
+func TestNewAcc(t *testing.T) {
+
+	api, control := setup(t)
+	verifyNum := func(num int) {
+		if list := list(control, api, t); len(list) != num {
+			t.Errorf("Expected %d accounts, got %d", num, len(list))
+		}
+	}
+	// Testing create and create-deny
+	createAccount(control, api, t)
+	createAccount(control, api, t)
+	failCreateAccount(control, api, t)
+	failCreateAccount(control, api, t)
+	createAccount(control, api, t)
+	failCreateAccount(control, api, t)
+	createAccount(control, api, t)
+	failCreateAccount(control, api, t)
+	verifyNum(4)
+
+	// Testing listing:
+	// Listing one Account
+	control <- "1"
+	list, err := api.List(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(list) != 1 {
+		t.Fatalf("List should only show one Account")
+	}
+	// Listing denied
+	control <- "Nope"
+	list, err = api.List(context.Background())
+	if len(list) != 0 {
+		t.Fatalf("List should be empty")
+	}
+	if err != ErrRequestDenied {
+		t.Fatal("Expected deny")
+	}
+}
+
+func TestSignData(t *testing.T) {
+
+	api, control := setup(t)
+	//Create two accounts
+	createAccount(control, api, t)
+	createAccount(control, api, t)
+	control <- "1"
+	list, err := api.List(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	a := common.NewMixedcaseAddress(list[0].Address)
+
+	control <- "Y"
+	control <- "wrongpassword"
+	h, err := api.Sign(context.Background(), a, []byte("EHLO world"))
+	if h != nil {
+		t.Errorf("Expected nil-data, got %x", h)
+	}
+	if err != keystore.ErrDecrypt {
+		t.Errorf("Expected ErrLocked! %v", err)
+	}
+
+	control <- "No way"
+	h, err = api.Sign(context.Background(), a, []byte("EHLO world"))
+	if h != nil {
+		t.Errorf("Expected nil-data, got %x", h)
+	}
+	if err != ErrRequestDenied {
+		t.Errorf("Expected ErrRequestDenied! %v", err)
+	}
+
+	control <- "Y"
+	control <- "apassword"
+	h, err = api.Sign(context.Background(), a, []byte("EHLO world"))
+
+	if err != nil {
+		t.Fatal(err)
+	}
+	if h == nil || len(h) != 65 {
+		t.Errorf("Expected 65 byte signature (got %d bytes)", len(h))
+	}
+}
+func mkTestTx(from common.MixedcaseAddress) SendTxArgs {
+	to := common.NewMixedcaseAddress(common.HexToAddress("0x1337"))
+	gas := hexutil.Uint64(21000)
+	gasPrice := (hexutil.Big)(*big.NewInt(2000000000))
+	value := (hexutil.Big)(*big.NewInt(1e18))
+	nonce := (hexutil.Uint64)(0)
+	data := hexutil.Bytes(common.Hex2Bytes("01020304050607080a"))
+	tx := SendTxArgs{
+		From:     from,
+		To:       &to,
+		Gas:      gas,
+		GasPrice: gasPrice,
+		Value:    value,
+		Data:     &data,
+		Nonce:    nonce}
+	return tx
+}
+
+func TestSignTx(t *testing.T) {
+
+	var (
+		list      Accounts
+		res, res2 *ethapi.SignTransactionResult
+		err       error
+	)
+
+	api, control := setup(t)
+	createAccount(control, api, t)
+	control <- "A"
+	list, err = api.List(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	a := common.NewMixedcaseAddress(list[0].Address)
+
+	methodSig := "test(uint)"
+	tx := mkTestTx(a)
+
+	control <- "Y"
+	control <- "wrongpassword"
+	res, err = api.SignTransaction(context.Background(), tx, &methodSig)
+	if res != nil {
+		t.Errorf("Expected nil-response, got %v", res)
+	}
+	if err != keystore.ErrDecrypt {
+		t.Errorf("Expected ErrLocked! %v", err)
+	}
+
+	control <- "No way"
+	res, err = api.SignTransaction(context.Background(), tx, &methodSig)
+	if res != nil {
+		t.Errorf("Expected nil-response, got %v", res)
+	}
+	if err != ErrRequestDenied {
+		t.Errorf("Expected ErrRequestDenied! %v", err)
+	}
+
+	control <- "Y"
+	control <- "apassword"
+	res, err = api.SignTransaction(context.Background(), tx, &methodSig)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+	parsedTx := &types.Transaction{}
+	rlp.Decode(bytes.NewReader(res.Raw), parsedTx)
+	//The tx should NOT be modified by the UI
+	if parsedTx.Value().Cmp(tx.Value.ToInt()) != 0 {
+		t.Errorf("Expected value to be unchanged, expected %v got %v", tx.Value, parsedTx.Value())
+	}
+	control <- "Y"
+	control <- "apassword"
+
+	res2, err = api.SignTransaction(context.Background(), tx, &methodSig)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(res.Raw, res2.Raw) {
+		t.Error("Expected tx to be unmodified by UI")
+	}
+
+	//The tx is modified by the UI
+	control <- "M"
+	control <- "apassword"
+
+	res2, err = api.SignTransaction(context.Background(), tx, &methodSig)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	parsedTx2 := &types.Transaction{}
+	rlp.Decode(bytes.NewReader(res.Raw), parsedTx2)
+	//The tx should be modified by the UI
+	if parsedTx2.Value().Cmp(tx.Value.ToInt()) != 0 {
+		t.Errorf("Expected value to be unchanged, got %v", parsedTx.Value())
+	}
+
+	if bytes.Equal(res.Raw, res2.Raw) {
+		t.Error("Expected tx to be modified by UI")
+	}
+
+}
+
+/*
+func TestAsyncronousResponses(t *testing.T){
+
+	//Set up one account
+	api, control := setup(t)
+	createAccount(control, api, t)
+
+	// Two transactions, the second one with larger value than the first
+	tx1 := mkTestTx()
+	newVal := big.NewInt(0).Add((*big.Int) (tx1.Value), big.NewInt(1))
+	tx2 := mkTestTx()
+	tx2.Value = (*hexutil.Big)(newVal)
+
+	control <- "W" //wait
+	control <- "Y" //
+	control <- "apassword"
+	control <- "Y" //
+	control <- "apassword"
+
+	var err error
+
+	h1, err := api.SignTransaction(context.Background(), common.HexToAddress("1111"), tx1, nil)
+	h2, err := api.SignTransaction(context.Background(), common.HexToAddress("2222"), tx2, nil)
+
+
+	}
+*/

signer/core/auditlog.go

+// Copyright 2018 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+package core
+
+import (
+	"context"
+
+	"encoding/json"
+
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/internal/ethapi"
+	"github.com/ethereum/go-ethereum/log"
+)
+
+type AuditLogger struct {
+	log log.Logger
+	api ExternalAPI
+}
+
+func (l *AuditLogger) List(ctx context.Context) (Accounts, error) {
+	l.log.Info("List", "type", "request", "metadata", MetadataFromContext(ctx).String())
+	res, e := l.api.List(ctx)
+
+	l.log.Info("List", "type", "response", "data", res.String())
+
+	return res, e
+}
+
+func (l *AuditLogger) New(ctx context.Context) (accounts.Account, error) {
+	return l.api.New(ctx)
+}
+
+func (l *AuditLogger) SignTransaction(ctx context.Context, args SendTxArgs, methodSelector *string) (*ethapi.SignTransactionResult, error) {
+	sel := "<nil>"
+	if methodSelector != nil {
+		sel = *methodSelector
+	}
+	l.log.Info("SignTransaction", "type", "request", "metadata", MetadataFromContext(ctx).String(),
+		"tx", args.String(),
+		"methodSelector", sel)
+
+	res, e := l.api.SignTransaction(ctx, args, methodSelector)
+	if res != nil {
+		l.log.Info("SignTransaction", "type", "response", "data", common.Bytes2Hex(res.Raw), "error", e)
+	} else {
+		l.log.Info("SignTransaction", "type", "response", "data", res, "error", e)
+	}
+	return res, e
+}
+
+func (l *AuditLogger) Sign(ctx context.Context, addr common.MixedcaseAddress, data hexutil.Bytes) (hexutil.Bytes, error) {
+	l.log.Info("Sign", "type", "request", "metadata", MetadataFromContext(ctx).String(),
+		"addr", addr.String(), "data", common.Bytes2Hex(data))
+	b, e := l.api.Sign(ctx, addr, data)
+	l.log.Info("Sign", "type", "response", "data", common.Bytes2Hex(b), "error", e)
+	return b, e
+}
+
+func (l *AuditLogger) EcRecover(ctx context.Context, data, sig hexutil.Bytes) (common.Address, error) {
+	l.log.Info("EcRecover", "type", "request", "metadata", MetadataFromContext(ctx).String(),
+		"data", common.Bytes2Hex(data))
+	a, e := l.api.EcRecover(ctx, data, sig)
+	l.log.Info("EcRecover", "type", "response", "addr", a.String(), "error", e)
+	return a, e
+}
+
+func (l *AuditLogger) Export(ctx context.Context, addr common.Address) (json.RawMessage, error) {
+	l.log.Info("Export", "type", "request", "metadata", MetadataFromContext(ctx).String(),
+		"addr", addr.Hex())
+	j, e := l.api.Export(ctx, addr)
+	// In this case, we don't actually log the json-response, which may be extra sensitive
+	l.log.Info("Export", "type", "response", "json response size", len(j), "error", e)
+	return j, e
+}
+
+func (l *AuditLogger) Import(ctx context.Context, keyJSON json.RawMessage) (Account, error) {
+	// Don't actually log the json contents
+	l.log.Info("Import", "type", "request", "metadata", MetadataFromContext(ctx).String(),
+		"keyJSON size", len(keyJSON))
+	a, e := l.api.Import(ctx, keyJSON)
+	l.log.Info("Import", "type", "response", "addr", a.String(), "error", e)
+	return a, e
+}
+
+func NewAuditLogger(path string, api ExternalAPI) (*AuditLogger, error) {
+	l := log.New("api", "signer")
+	handler, err := log.FileHandler(path, log.LogfmtFormat())
+	if err != nil {
+		return nil, err
+	}
+	l.SetHandler(handler)
+	l.Info("Configured", "audit log", path)
+	return &AuditLogger{l, api}, nil
+}

signer/core/cliui.go

+// Copyright 2018 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+package core
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strings"
+
+	"sync"
+
+	"github.com/davecgh/go-spew/spew"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/internal/ethapi"
+	"github.com/ethereum/go-ethereum/log"
+	"golang.org/x/crypto/ssh/terminal"
+)
+
+type CommandlineUI struct {
+	in *bufio.Reader
+	mu sync.Mutex
+}
+
+func NewCommandlineUI() *CommandlineUI {
+	return &CommandlineUI{in: bufio.NewReader(os.Stdin)}
+}
+
+// readString reads a single line from stdin, trimming if from spaces, enforcing
+// non-emptyness.
+func (ui *CommandlineUI) readString() string {
+	for {
+		fmt.Printf("> ")
+		text, err := ui.in.ReadString('\n')
+		if err != nil {
+			log.Crit("Failed to read user input", "err", err)
+		}
+		if text = strings.TrimSpace(text); text != "" {
+			return text
+		}
+	}
+}
+
+// readPassword reads a single line from stdin, trimming it from the trailing new
+// line and returns it. The input will not be echoed.
+func (ui *CommandlineUI) readPassword() string {
+	fmt.Printf("Enter password to approve:\n")
+	fmt.Printf("> ")
+
+	text, err := terminal.ReadPassword(int(os.Stdin.Fd()))
+	if err != nil {
+		log.Crit("Failed to read password", "err", err)
+	}
+	fmt.Println()
+	fmt.Println("-----------------------")
+	return string(text)
+}
+
+// readPassword reads a single line from stdin, trimming it from the trailing new
+// line and returns it. The input will not be echoed.
+func (ui *CommandlineUI) readPasswordText(inputstring string) string {
+	fmt.Printf("Enter %s:\n", inputstring)
+	fmt.Printf("> ")
+	text, err := terminal.ReadPassword(int(os.Stdin.Fd()))
+	if err != nil {
+		log.Crit("Failed to read password", "err", err)
+	}
+	fmt.Println("-----------------------")
+	return string(text)
+}
+
+// confirm returns true if user enters 'Yes', otherwise false
+func (ui *CommandlineUI) confirm() bool {
+	fmt.Printf("Approve? [y/N]:\n")
+	if ui.readString() == "y" {
+		return true
+	}
+	fmt.Println("-----------------------")
+	return false
+}
+
+func showMetadata(metadata Metadata) {
+	fmt.Printf("Request context:\n\t%v -> %v -> %v\n", metadata.Remote, metadata.Scheme, metadata.Local)
+}
+
+// ApproveTx prompt the user for confirmation to request to sign Transaction
+func (ui *CommandlineUI) ApproveTx(request *SignTxRequest) (SignTxResponse, error) {
+	ui.mu.Lock()
+	defer ui.mu.Unlock()
+	weival := request.Transaction.Value.ToInt()
+	fmt.Printf("--------- Transaction request-------------\n")
+	if to := request.Transaction.To; to != nil {
+		fmt.Printf("to:    %v\n", to.Original())
+		if !to.ValidChecksum() {
+			fmt.Printf("\nWARNING: Invalid checksum on to-address!\n\n")
+		}
+	} else {
+		fmt.Printf("to:    <contact creation>\n")
+	}
+	fmt.Printf("from:  %v\n", request.Transaction.From.String())
+	fmt.Printf("value: %v wei\n", weival)
+	if request.Transaction.Data != nil {
+		d := *request.Transaction.Data
+		if len(d) > 0 {
+			fmt.Printf("data:  %v\n", common.Bytes2Hex(d))
+		}
+	}
+	if request.Callinfo != nil {
+		fmt.Printf("\nTransaction validation:\n")
+		for _, m := range request.Callinfo {
+			fmt.Printf("  * %s : %s", m.Typ, m.Message)
+		}
+		fmt.Println()
+
+	}
+	fmt.Printf("\n")
+	showMetadata(request.Meta)
+	fmt.Printf("-------------------------------------------\n")
+	if !ui.confirm() {
+		return SignTxResponse{request.Transaction, false, ""}, nil
+	}
+	return SignTxResponse{request.Transaction, true, ui.readPassword()}, nil
+}
+
+// ApproveSignData prompt the user for confirmation to request to sign data
+func (ui *CommandlineUI) ApproveSignData(request *SignDataRequest) (SignDataResponse, error) {
+	ui.mu.Lock()
+	defer ui.mu.Unlock()
+
+	fmt.Printf("-------- Sign data request--------------\n")
+	fmt.Printf("Account:  %s\n", request.Address.String())
+	fmt.Printf("message:  \n%q\n", request.Message)
+	fmt.Printf("raw data: \n%v\n", request.Rawdata)
+	fmt.Printf("message hash:  %v\n", request.Hash)
+	fmt.Printf("-------------------------------------------\n")
+	showMetadata(request.Meta)
+	if !ui.confirm() {
+		return SignDataResponse{false, ""}, nil
+	}
+	return SignDataResponse{true, ui.readPassword()}, nil
+}
+
+// ApproveExport prompt the user for confirmation to export encrypted Account json
+func (ui *CommandlineUI) ApproveExport(request *ExportRequest) (ExportResponse, error) {
+	ui.mu.Lock()
+	defer ui.mu.Unlock()
+
+	fmt.Printf("-------- Export Account request--------------\n")
+	fmt.Printf("A request has been made to export the (encrypted) keyfile\n")
+	fmt.Printf("Approving this operation means that the caller obtains the (encrypted) contents\n")
+	fmt.Printf("\n")
+	fmt.Printf("Account:  %x\n", request.Address)
+	//fmt.Printf("keyfile:  \n%v\n", request.file)
+	fmt.Printf("-------------------------------------------\n")
+	showMetadata(request.Meta)
+	return ExportResponse{ui.confirm()}, nil
+}
+
+// ApproveImport prompt the user for confirmation to import Account json
+func (ui *CommandlineUI) ApproveImport(request *ImportRequest) (ImportResponse, error) {
+	ui.mu.Lock()
+	defer ui.mu.Unlock()
+
+	fmt.Printf("-------- Import Account request--------------\n")
+	fmt.Printf("A request has been made to import an encrypted keyfile\n")
+	fmt.Printf("-------------------------------------------\n")
+	showMetadata(request.Meta)
+	if !ui.confirm() {
+		return ImportResponse{false, "", ""}, nil
+	}
+	return ImportResponse{true, ui.readPasswordText("Old password"), ui.readPasswordText("New password")}, nil
+}
+
+// ApproveListing prompt the user for confirmation to list accounts
+// the list of accounts to list can be modified by the UI
+func (ui *CommandlineUI) ApproveListing(request *ListRequest) (ListResponse, error) {
+
+	ui.mu.Lock()
+	defer ui.mu.Unlock()
+
+	fmt.Printf("-------- List Account request--------------\n")
+	fmt.Printf("A request has been made to list all accounts. \n")
+	fmt.Printf("You can select which accounts the caller can see\n")
+	for _, account := range request.Accounts {
+		fmt.Printf("\t[x] %v\n", account.Address.Hex())
+	}
+	fmt.Printf("-------------------------------------------\n")
+	showMetadata(request.Meta)
+	if !ui.confirm() {
+		return ListResponse{nil}, nil
+	}
+	return ListResponse{request.Accounts}, nil
+}
+
+// ApproveNewAccount prompt the user for confirmation to create new Account, and reveal to caller
+func (ui *CommandlineUI) ApproveNewAccount(request *NewAccountRequest) (NewAccountResponse, error) {
+
+	ui.mu.Lock()
+	defer ui.mu.Unlock()
+
+	fmt.Printf("-------- New Account request--------------\n")
+	fmt.Printf("A request has been made to create a new. \n")
+	fmt.Printf("Approving this operation means that a new Account is created,\n")
+	fmt.Printf("and the address show to the caller\n")
+	showMetadata(request.Meta)
+	if !ui.confirm() {
+		return NewAccountResponse{false, ""}, nil
+	}
+	return NewAccountResponse{true, ui.readPassword()}, nil
+}
+
+// ShowError displays error message to user
+func (ui *CommandlineUI) ShowError(message string) {
+
+	fmt.Printf("ERROR: %v\n", message)
+}
+
+// ShowInfo displays info message to user
+func (ui *CommandlineUI) ShowInfo(message string) {
+	fmt.Printf("Info: %v\n", message)
+}
+
+func (ui *CommandlineUI) OnApprovedTx(tx ethapi.SignTransactionResult) {
+	fmt.Printf("Transaction signed:\n ")
+	spew.Dump(tx.Tx)
+}
+
+func (ui *CommandlineUI) OnSignerStartup(info StartupInfo) {
+
+	fmt.Printf("------- Signer info -------\n")
+	for k, v := range info.Info {
+		fmt.Printf("* %v : %v\n", k, v)
+	}
+}

signer/core/stdioui.go

+// Copyright 2018 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+//
+
+package core
+
+import (
+	"context"
+	"sync"
+
+	"github.com/ethereum/go-ethereum/internal/ethapi"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/rpc"
+)
+
+type StdIOUI struct {
+	client rpc.Client
+	mu     sync.Mutex
+}
+
+func NewStdIOUI() *StdIOUI {
+	log.Info("NewStdIOUI")
+	client, err := rpc.DialContext(context.Background(), "stdio://")
+	if err != nil {
+		log.Crit("Could not create stdio client", "err", err)
+	}
+	return &StdIOUI{client: *client}
+}
+
+// dispatch sends a request over the stdio
+func (ui *StdIOUI) dispatch(serviceMethod string, args interface{}, reply interface{}) error {
+	err := ui.client.Call(&reply, serviceMethod, args)
+	if err != nil {
+		log.Info("Error", "exc", err.Error())
+	}
+	return err
+}
+
+func (ui *StdIOUI) ApproveTx(request *SignTxRequest) (SignTxResponse, error) {
+	var result SignTxResponse
+	err := ui.dispatch("ApproveTx", request, &result)
+	return result, err
+}
+
+func (ui *StdIOUI) ApproveSignData(request *SignDataRequest) (SignDataResponse, error) {
+	var result SignDataResponse
+	err := ui.dispatch("ApproveSignData", request, &result)
+	return result, err
+}
+
+func (ui *StdIOUI) ApproveExport(request *ExportRequest) (ExportResponse, error) {
+	var result ExportResponse
+	err := ui.dispatch("ApproveExport", request, &result)
+	return result, err
+}
+
+func (ui *StdIOUI) ApproveImport(request *ImportRequest) (ImportResponse, error) {
+	var result ImportResponse
+	err := ui.dispatch("ApproveImport", request, &result)
+	return result, err
+}
+
+func (ui *StdIOUI) ApproveListing(request *ListRequest) (ListResponse, error) {
+	var result ListResponse
+	err := ui.dispatch("ApproveListing", request, &result)
+	return result, err
+}
+
+func (ui *StdIOUI) ApproveNewAccount(request *NewAccountRequest) (NewAccountResponse, error) {
+	var result NewAccountResponse
+	err := ui.dispatch("ApproveNewAccount", request, &result)
+	return result, err
+}
+
+func (ui *StdIOUI) ShowError(message string) {
+	err := ui.dispatch("ShowError", &Message{message}, nil)
+	if err != nil {
+		log.Info("Error calling 'ShowError'", "exc", err.Error(), "msg", message)
+	}
+}
+
+func (ui *StdIOUI) ShowInfo(message string) {
+	err := ui.dispatch("ShowInfo", Message{message}, nil)
+	if err != nil {
+		log.Info("Error calling 'ShowInfo'", "exc", err.Error(), "msg", message)
+	}
+}
+func (ui *StdIOUI) OnApprovedTx(tx ethapi.SignTransactionResult) {
+	err := ui.dispatch("OnApprovedTx", tx, nil)
+	if err != nil {
+		log.Info("Error calling 'OnApprovedTx'", "exc", err.Error(), "tx", tx)
+	}
+}
+
+func (ui *StdIOUI) OnSignerStartup(info StartupInfo) {
+	err := ui.dispatch("OnSignerStartup", info, nil)
+	if err != nil {
+		log.Info("Error calling 'OnSignerStartup'", "exc", err.Error(), "info", info)
+	}
+}

signer/core/types.go

+// Copyright 2018 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+package core
+
+import (
+	"encoding/json"
+	"strings"
+
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/core/types"
+)
+
+type Accounts []Account
+
+func (as Accounts) String() string {
+	var output []string
+	for _, a := range as {
+		output = append(output, a.String())
+	}
+	return strings.Join(output, "\n")
+}
+
+type Account struct {
+	Typ     string         `json:"type"`
+	URL     accounts.URL   `json:"url"`
+	Address common.Address `json:"address"`
+}
+
+func (a Account) String() string {
+	s, err := json.Marshal(a)
+	if err == nil {
+		return string(s)
+	}
+	return err.Error()
+}
+
+type ValidationInfo struct {
+	Typ     string `json:"type"`
+	Message string `json:"message"`
+}
+type ValidationMessages struct {
+	Messages []ValidationInfo
+}
+
+// SendTxArgs represents the arguments to submit a transaction
+type SendTxArgs struct {
+	From     common.MixedcaseAddress  `json:"from"`
+	To       *common.MixedcaseAddress `json:"to"`
+	Gas      hexutil.Uint64           `json:"gas"`
+	GasPrice hexutil.Big              `json:"gasPrice"`
+	Value    hexutil.Big              `json:"value"`
+	Nonce    hexutil.Uint64           `json:"nonce"`
+	// We accept "data" and "input" for backwards-compatibility reasons.
+	Data  *hexutil.Bytes `json:"data"`
+	Input *hexutil.Bytes `json:"input"`
+}
+
+func (t SendTxArgs) String() string {
+	s, err := json.Marshal(t)
+	if err == nil {
+		return string(s)
+	}
+	return err.Error()
+}
+
+func (args *SendTxArgs) toTransaction() *types.Transaction {
+	var input []byte
+	if args.Data != nil {
+		input = *args.Data
+	} else if args.Input != nil {
+		input = *args.Input
+	}
+	if args.To == nil {
+		return types.NewContractCreation(uint64(args.Nonce), (*big.Int)(&args.Value), uint64(args.Gas), (*big.Int)(&args.GasPrice), input)
+	}
+	return types.NewTransaction(uint64(args.Nonce), args.To.Address(), (*big.Int)(&args.Value), (uint64)(args.Gas), (*big.Int)(&args.GasPrice), input)
+}

signer/core/validation.go

+// Copyright 2018 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+package core
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+// The validation package contains validation checks for transactions
+// - ABI-data validation
+// - Transaction semantics validation
+// The package provides warnings for typical pitfalls
+
+func (vs *ValidationMessages) crit(msg string) {
+	vs.Messages = append(vs.Messages, ValidationInfo{"CRITICAL", msg})
+}
+func (vs *ValidationMessages) warn(msg string) {
+	vs.Messages = append(vs.Messages, ValidationInfo{"WARNING", msg})
+}
+func (vs *ValidationMessages) info(msg string) {
+	vs.Messages = append(vs.Messages, ValidationInfo{"Info", msg})
+}
+
+type Validator struct {
+	db *AbiDb
+}
+
+func NewValidator(db *AbiDb) *Validator {
+	return &Validator{db}
+}
+func testSelector(selector string, data []byte) (*decodedCallData, error) {
+	if selector == "" {
+		return nil, fmt.Errorf("selector not found")
+	}
+	abiData, err := MethodSelectorToAbi(selector)
+	if err != nil {
+		return nil, err
+	}
+	info, err := parseCallData(data, string(abiData))
+	if err != nil {
+		return nil, err
+	}
+	return info, nil
+
+}
+
+// validateCallData checks if the ABI-data + methodselector (if given) can be parsed and seems to match
+func (v *Validator) validateCallData(msgs *ValidationMessages, data []byte, methodSelector *string) {
+	if len(data) == 0 {
+		return
+	}
+	if len(data) < 4 {
+		msgs.warn("Tx contains data which is not valid ABI")
+		return
+	}
+	var (
+		info *decodedCallData
+		err  error
+	)
+	// Check the provided one
+	if methodSelector != nil {
+		info, err = testSelector(*methodSelector, data)
+		if err != nil {
+			msgs.warn(fmt.Sprintf("Tx contains data, but provided ABI signature could not be matched: %v", err))
+		} else {
+			msgs.info(info.String())
+			//Successfull match. add to db if not there already (ignore errors there)
+			v.db.AddSignature(*methodSelector, data[:4])
+		}
+		return
+	}
+	// Check the db
+	selector, err := v.db.LookupMethodSelector(data[:4])
+	if err != nil {
+		msgs.warn(fmt.Sprintf("Tx contains data, but the ABI signature could not be found: %v", err))
+		return
+	}
+	info, err = testSelector(selector, data)
+	if err != nil {
+		msgs.warn(fmt.Sprintf("Tx contains data, but provided ABI signature could not be matched: %v", err))
+	} else {
+		msgs.info(info.String())
+	}
+}
+
+// validateSemantics checks if the transactions 'makes sense', and generate warnings for a couple of typical scenarios
+func (v *Validator) validate(msgs *ValidationMessages, txargs *SendTxArgs, methodSelector *string) error {
+	// Prevent accidental erroneous usage of both 'input' and 'data'
+	if txargs.Data != nil && txargs.Input != nil && !bytes.Equal(*txargs.Data, *txargs.Input) {
+		// This is a showstopper
+		return errors.New(`Ambiguous request: both "data" and "input" are set and are not identical`)
+	}
+	var (
+		data []byte
+	)
+	// Place data on 'data', and nil 'input'
+	if txargs.Input != nil {
+		txargs.Data = txargs.Input
+		txargs.Input = nil
+	}
+	if txargs.Data != nil {
+		data = *txargs.Data
+	}
+
+	if txargs.To == nil {
+		//Contract creation should contain sufficient data to deploy a contract
+		// A typical error is omitting sender due to some quirk in the javascript call
+		// e.g. https://github.com/ethereum/go-ethereum/issues/16106
+		if len(data) == 0 {
+			if txargs.Value.ToInt().Cmp(big.NewInt(0)) > 0 {
+				// Sending ether into black hole
+				return errors.New(`Tx will create contract with value but empty code!`)
+			}
+			// No value submitted at least
+			msgs.crit("Tx will create contract with empty code!")
+		} else if len(data) < 40 { //Arbitrary limit
+			msgs.warn(fmt.Sprintf("Tx will will create contract, but payload is suspiciously small (%d b)", len(data)))
+		}
+		// methodSelector should be nil for contract creation
+		if methodSelector != nil {
+			msgs.warn("Tx will create contract, but method selector supplied; indicating intent to call a method.")
+		}
+
+	} else {
+		if !txargs.To.ValidChecksum() {
+			msgs.warn("Invalid checksum on to-address")
+		}
+		// Normal transaction
+		if bytes.Equal(txargs.To.Address().Bytes(), common.Address{}.Bytes()) {
+			// Sending to 0
+			msgs.crit("Tx destination is the zero address!")
+		}
+		// Validate calldata
+		v.validateCallData(msgs, data, methodSelector)
+	}
+	return nil
+}
+
+// ValidateTransaction does a number of checks on the supplied transaction, and returns either a list of warnings,
+// or an error, indicating that the transaction should be immediately rejected
+func (v *Validator) ValidateTransaction(txArgs *SendTxArgs, methodSelector *string) (*ValidationMessages, error) {
+	msgs := &ValidationMessages{}
+	return msgs, v.validate(msgs, txArgs, methodSelector)
+}

signer/rules/deps/deps.go

+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package deps contains the console JavaScript dependencies Go embedded.
+package deps
+
+//go:generate go-bindata -nometadata -pkg deps -o bindata.go bignumber.js
+//go:generate gofmt -w -s bindata.go

signer/storage/storage.go

+// Copyright 2018 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+//
+
+package storage
+
+import (
+	"fmt"
+)
+
+type Storage interface {
+	// Put stores a value by key. 0-length keys results in no-op
+	Put(key, value string)
+	// Get returns the previously stored value, or the empty string if it does not exist or key is of 0-length
+	Get(key string) string
+}
+
+// EphemeralStorage is an in-memory storage that does
+// not persist values to disk. Mainly used for testing
+type EphemeralStorage struct {
+	data      map[string]string
+	namespace string
+}
+
+func (s *EphemeralStorage) Put(key, value string) {
+	if len(key) == 0 {
+		return
+	}
+	fmt.Printf("storage: put %v -> %v\n", key, value)
+	s.data[key] = value
+}
+
+func (s *EphemeralStorage) Get(key string) string {
+	if len(key) == 0 {
+		return ""
+	}
+	fmt.Printf("storage: get %v\n", key)
+	if v, exist := s.data[key]; exist {
+		return v
+	}
+	return ""
+}
+
+func NewEphemeralStorage() Storage {
+	s := &EphemeralStorage{
+		data: make(map[string]string),
+	}
+	return s
+}