Feature: Add isWeb3Checksummed function

eval/eval.go

@@ -32,8 +32,9 @@ type RunResponse struct {
 
 var exprEnvOptions = []expr.Option{
 	expr.AsAny(),
-	// Inject a custom isSorted function into the environment.
+	// Inject a custom functions into the environment.
 	functions.IsSorted(),
+	functions.IsWeb3Checksummed(),
 
   // Provide a constant timestamp to the expression environment.
 	expr.DisableBuiltin("now"),

examples.yaml

@@ -488,6 +488,18 @@ examples:
         upstream_host_metadata: "NULL"
     category: "Istio"
 
+  - name: "Address checksummed"
+    expr: |
+      isWeb3Checksummed(network_1.address) && isWeb3Checksummed(network_2.addresses)
+    data: |
+      network_1:
+        address: 0xb0F001C7F6C665b7b8e12F29EDC1107613fe980D
+      network_2:
+        addresses:
+          - 0xb0F001C7F6C665b7b8e12F29EDC1107613fe980D
+          - 0x3106E2e148525b3DB36795b04691D444c24972fB
+    category: "Web3"
+
   - name: "Blank"
     expr: ""
     data: ""

functions/is_web3_checksum.go

@@ -0,0 +1,115 @@
+// Copyright 2024 Peter Olds <[email protected]>
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package functions
+
+import (
+	"encoding/hex"
+	"fmt"
+	"reflect"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/expr-lang/expr"
+)
+
+// IsWeb3Checksummed is a function that checks whether the given address (or list of addresses) is checksummed. It is provided as an Expr function.
+// It supports the following types:
+// - string
+// - []any (which should contain only string elements)
+
+// Examples:
+// - isWeb3Checksummed("0xb0F001C7F6C665b7b8e12F29EDC1107613fe980D")
+// - isWeb3Checksummed(["0xb0F001C7F6C665b7b8e12F29EDC1107613fe980D", "0x3106E2e148525b3DB36795b04691D444c24972fB"])
+func IsWeb3Checksummed() expr.Option {
+	return expr.Function("isWeb3Checksummed", func(params ...any) (any, error) {
+		return isWeb3Checksummed(params[0])
+	},
+		new(func([]any) (bool, error)),
+		new(func(string) (bool, error)),
+	)
+}
+
+func isWeb3Checksummed(v any) (any, error) {
+	if v == nil {
+		return false, nil
+	}
+
+	switch t := v.(type) {
+	case []any:
+		return arrayChecksummed(t)
+	case string:
+		return checksummed(t)
+	default:
+		return false, fmt.Errorf("type %s is not supported", reflect.TypeOf(v))
+	}
+}
+
+func arrayChecksummed(v []any) (bool, error) {
+	switch t := v[0].(type) {
+	case string:
+		for _, address := range v {
+			res, err := checksummed(address.(string))
+			if err != nil || !res {
+				return res, err
+			}
+		}
+		return true, nil
+	default:
+		return false, fmt.Errorf("unsupported type %T", t)
+	}
+}
+
+func checksummed(address string) (bool, error) {
+	if len(address) != 42 {
+		return false, fmt.Errorf("Address needs to be 42 characters long")
+	}
+
+	if !strings.HasPrefix(address, "0x") {
+		return false, fmt.Errorf("Address needs to start with 0x")
+	}
+
+	return common.IsHexAddress(address) && checksumAddress(address) == address, nil
+}
+
+// Algorithm for checksumming a web3 address:
+// - Convert the address to lowercase
+// - Hash the address usinga keccak256
+// - Take 40 characters of the hash, drop the rest (40 because of the address length)
+// - Iterate through each character in the original address
+//   - If the checksum character >= 8 and character in the original address at the same idx is [a, f] then capitalize
+//   - Otherwise, add character
+//
+// For visualization, you can watch the following video: https://www.youtube.com/watch?v=2vH_CQ_rvbc
+func checksumAddress(address string) string {
+	if strings.HasPrefix(address, "0x") {
+		address = address[2:]
+	}
+
+	lowercaseAddress := strings.ToLower(address)
+	hashedAddress := crypto.Keccak256([]byte(lowercaseAddress))
+	checksum := hex.EncodeToString(hashedAddress)[:40]
+
+	var checksumAddress strings.Builder
+	for idx, char := range lowercaseAddress {
+		if checksum[idx] >= '8' && (char >= 'a' && char <= 'f') {
+			checksumAddress.WriteRune(char - 32)
+		} else {
+			checksumAddress.WriteRune(char)
+		}
+	}
+
+	return "0x" + checksumAddress.String()
+}

functions/is_web3_checksum_test.go

@@ -0,0 +1,118 @@
+// Copyright 2024 Peter Olds <[email protected]>
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package functions
+
+import (
+	"testing"
+
+	"github.com/expr-lang/expr"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestIsWeb3Checksummed(t *testing.T) {
+	tests := []struct {
+		name           string
+		expr           string
+		want           bool
+		wantCompileErr bool
+		wantRuntimeErr bool
+	}{
+		{
+			name: "nil",
+			expr: `isWeb3Checksummed(nil)`,
+			want: false,
+		},
+		{
+			name: "string - not checksummed",
+			expr: `isWeb3Checksummed('0x30F4283a3d6302f968909Ff7c02ceCB2ac6C27Ac')`,
+			want: false,
+		},
+		{
+			name: "string - checksummed",
+			expr: `isWeb3Checksummed('0x30D873664Ba766C983984C7AF9A921ccE36D34e1')`,
+			want: true,
+		},
+		{
+			name: "string slice - checksummed",
+			expr: `isWeb3Checksummed(['0x55028780918330FD00a34a61D9a7Efd3f43ca845', '0xAA95A3e367b427477bAdAB3d104f7D04ba158895'])`,
+			want: true,
+		},
+		{
+			name: "string slice - checksummed",
+			expr: `isWeb3Checksummed(['0x869C8ADA0fb9AfC753159b7D6D72Cc8bf58e6987', '0x2a92BCecd6e702702864E134821FD2DE73C3e180'])`,
+			want: false,
+		},
+		{
+			name:           "address needs to start with 0x",
+			expr:           `isWeb3Checksummed('0034B03Cb9086d7D758AC55af71584F81A598759FE')`,
+			wantRuntimeErr: true,
+		},
+		{
+			name:           "address needs to be 42 characters long",
+			expr:           `isWeb3Checksummed('34B03Cb9086d7D758AC55af71584F81A598759FE')`,
+			wantRuntimeErr: true,
+		},
+		{
+			name:           "unsupported type int",
+			expr:           `isWeb3Checksummed(0)`,
+			wantCompileErr: true,
+		},
+		{
+			name:           "unsupported type int",
+			expr:           `isWeb3Checksummed([0])`,
+			wantRuntimeErr: true,
+		},
+		{
+			name:           "not enough arguments",
+			expr:           `isWeb3Checksummed()`,
+			wantCompileErr: true,
+		},
+	}
+
+	opts := []expr.Option{
+		expr.AsBool(),
+		expr.DisableAllBuiltins(),
+		IsWeb3Checksummed(),
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			program, err := expr.Compile(tc.expr, opts...)
+			if tc.wantCompileErr && err == nil {
+				require.Error(t, err)
+			}
+			if !tc.wantCompileErr && err != nil {
+				require.NoError(t, err)
+			}
+			if tc.wantCompileErr {
+				return
+			}
+
+			got, err := expr.Run(program, nil)
+			if tc.wantRuntimeErr && err == nil {
+				require.Error(t, err)
+			}
+			if !tc.wantRuntimeErr && err != nil {
+				require.NoError(t, err)
+			}
+			if tc.wantRuntimeErr {
+				return
+			}
+			assert.IsType(t, tc.want, got)
+			assert.Equal(t, tc.want, got)
+		})
+	}
+}

go.mod

@@ -10,9 +10,15 @@ require (
 )
 
 require (
+	github.com/btcsuite/btcd/btcec/v2 v2.2.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 // indirect
+	github.com/ethereum/go-ethereum v1.13.10 // indirect
+	github.com/holiman/uint256 v1.2.4 // indirect
 	github.com/kr/pretty v0.3.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/rogpeppe/go-internal v1.11.0 // indirect
+	golang.org/x/crypto v0.17.0 // indirect
+	golang.org/x/sys v0.15.0 // indirect
 	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
 )

go.sum

@@ -1,10 +1,19 @@
+github.com/btcsuite/btcd/btcec/v2 v2.2.0 h1:fzn1qaOt32TuLjFlkzYSsBC35Q3KUjT1SwPxiMSCF5k=
+github.com/btcsuite/btcd/btcec/v2 v2.2.0/go.mod h1:U7MHm051Al6XmscBQ0BoNydpOTsFAn707034b5nY8zU=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/decred/dcrd/crypto/blake256 v1.0.0/go.mod h1:sQl2p6Y26YV+ZOcSTP6thNdn47hh8kt6rqSlvmrXFAc=
+github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 h1:YLtO71vCjJRCBcrPMtQ9nqBsqpA1m5sE92cU+pd5Mcc=
+github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1/go.mod h1:hyedUtir6IdtD/7lIxGeCxkaw7y45JueMRL4DIyJDKs=
+github.com/ethereum/go-ethereum v1.13.10 h1:Ppdil79nN+Vc+mXfge0AuUgmKWuVv4eMqzoIVSdqZek=
+github.com/ethereum/go-ethereum v1.13.10/go.mod h1:sc48XYQxCzH3fG9BcrXCOOgQk2JfZzNAmIKnceogzsA=
 github.com/expr-lang/expr v1.15.8 h1:FL8+d3rSSP4tmK9o+vKfSMqqpGL8n15pEPiHcnBpxoI=
 github.com/expr-lang/expr v1.15.8/go.mod h1:uCkhfG+x7fcZ5A5sXHKuQ07jGZRl6J0FCAaf2k4PtVQ=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/holiman/uint256 v1.2.4 h1:jUc4Nk8fm9jZabQuqr2JzednajVmBpC+oiTiXZJEApU=
+github.com/holiman/uint256 v1.2.4/go.mod h1:EOMSn4q6Nyt9P6efbI3bueV4e1b3dGlUCXeiRV4ng7E=
 github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
@@ -20,6 +29,10 @@ github.com/rogpeppe/go-internal v1.11.0 h1:cWPaGQEPrBb5/AsnsZesgZZ9yb1OQ+GOISoDN
 github.com/rogpeppe/go-internal v1.11.0/go.mod h1:ddIwULY96R17DhadqLgMfk9H9tvdUzkipdSkR5nkCZA=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+golang.org/x/crypto v0.17.0 h1:r8bRNjWL3GshPW3gkd+RpvzWrZAwPS49OmTGZ/uhM4k=
+golang.org/x/crypto v0.17.0/go.mod h1:gCAAfMLgwOJRpTjQ2zCCt2OcSfYMTeZVSRtQlPC7Nq4=
+golang.org/x/sys v0.15.0 h1:h48lPFYpsTvQJZF4EKyI4aLHaev3CxivZmv7yZig9pc=
+golang.org/x/sys v0.15.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=