fixed signing (tests) and signing verification of the machine ID Signature

Signed-off-by: Jürgen Eckel <juergen@riddleandcode.com>

docs/static/openapi.yml

@@ -46556,6 +46556,8 @@ paths:
                   type:
                     type: integer
                     format: int64
+                  machineIdSignature:
+                    type: string
         default:
           description: An unexpected error response.
           schema:
@@ -75415,6 +75417,8 @@ definitions:
       type:
         type: integer
         format: int64
+      machineIdSignature:
+        type: string
   planetmintgo.machine.Metadata:
     type: object
     properties:
@@ -75473,6 +75477,8 @@ definitions:
           type:
             type: integer
             format: int64
+          machineIdSignature:
+            type: string
   planetmintgo.machine.QueryParamsResponse:
     type: object
     properties:

testutil/sample/sample.go

@@ -61,7 +61,7 @@ func Machine(name, pubKey string, prvKey string) machinetypes.Machine {
 
 	prvKeyBytes, _ := hex.DecodeString(prvKey)
 	sk := &secp256k1.PrivKey{Key: prvKeyBytes}
-	pubKeyBytes := []byte(pubKey)
+	pubKeyBytes, _ := hex.DecodeString(pubKey)
 	sign, _ := sk.Sign(pubKeyBytes)
 	signatureHex := hex.EncodeToString(sign)
 

util/validate_signature.go

@@ -20,3 +20,18 @@ func ValidateSignature(message string, signature string, publicKey string) bool
 
 	return isValid
 }
+
+func ValidateSignature_hexstring(message string, signature string, publicKey string) bool {
+	// Convert the message, signature, and public key from hex to bytes
+	messageBytes, _ := hex.DecodeString(message)
+	signatureBytes, _ := hex.DecodeString(signature)
+	publicKeyBytes, _ := hex.DecodeString(publicKey)
+
+	// Create a secp256k1 public key object
+	pubKey := &secp256k1.PubKey{Key: publicKeyBytes}
+
+	// Verify the signature
+	isValid := pubKey.VerifySignature(messageBytes, signatureBytes)
+
+	return isValid
+}

x/machine/keeper/msg_server_attest_machine.go

@@ -33,7 +33,7 @@ func (k msgServer) AttestMachine(goCtx context.Context, msg *types.MsgAttestMach
 		return nil, errors.New("trust anchor has already been used for attestation")
 	}
 
-	isValidMachineId := util.ValidateSignature(msg.Machine.MachineId, msg.Machine.MachineIdSignature, msg.Machine.MachineId)
+	isValidMachineId := util.ValidateSignature_hexstring(msg.Machine.MachineId, msg.Machine.MachineIdSignature, msg.Machine.MachineId)
 	if !isValidMachineId {
 		return nil, errors.New("invalid machine id")
 	}