github.com/benorgera/go-ethereum@v1.10.18-0.20220401011646-b3f57b1a73ba/accounts/abi/unpack_test.go (about)

     1  // Copyright 2017 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package abi
    18  
    19  import (
    20  	"bytes"
    21  	"encoding/hex"
    22  	"fmt"
    23  	"math/big"
    24  	"reflect"
    25  	"strconv"
    26  	"strings"
    27  	"testing"
    28  
    29  	"github.com/ethereum/go-ethereum/common"
    30  	"github.com/stretchr/testify/require"
    31  )
    32  
    33  // TestUnpack tests the general pack/unpack tests in packing_test.go
    34  func TestUnpack(t *testing.T) {
    35  	for i, test := range packUnpackTests {
    36  		t.Run(strconv.Itoa(i)+" "+test.def, func(t *testing.T) {
    37  			//Unpack
    38  			def := fmt.Sprintf(`[{ "name" : "method", "type": "function", "outputs": %s}]`, test.def)
    39  			abi, err := JSON(strings.NewReader(def))
    40  			if err != nil {
    41  				t.Fatalf("invalid ABI definition %s: %v", def, err)
    42  			}
    43  			encb, err := hex.DecodeString(test.packed)
    44  			if err != nil {
    45  				t.Fatalf("invalid hex %s: %v", test.packed, err)
    46  			}
    47  			out, err := abi.Unpack("method", encb)
    48  			if err != nil {
    49  				t.Errorf("test %d (%v) failed: %v", i, test.def, err)
    50  				return
    51  			}
    52  			if !reflect.DeepEqual(test.unpacked, ConvertType(out[0], test.unpacked)) {
    53  				t.Errorf("test %d (%v) failed: expected %v, got %v", i, test.def, test.unpacked, out[0])
    54  			}
    55  		})
    56  	}
    57  }
    58  
    59  type unpackTest struct {
    60  	def  string      // ABI definition JSON
    61  	enc  string      // evm return data
    62  	want interface{} // the expected output
    63  	err  string      // empty or error if expected
    64  }
    65  
    66  func (test unpackTest) checkError(err error) error {
    67  	if err != nil {
    68  		if len(test.err) == 0 {
    69  			return fmt.Errorf("expected no err but got: %v", err)
    70  		} else if err.Error() != test.err {
    71  			return fmt.Errorf("expected err: '%v' got err: %q", test.err, err)
    72  		}
    73  	} else if len(test.err) > 0 {
    74  		return fmt.Errorf("expected err: %v but got none", test.err)
    75  	}
    76  	return nil
    77  }
    78  
    79  var unpackTests = []unpackTest{
    80  	// Bools
    81  	{
    82  		def:  `[{ "type": "bool" }]`,
    83  		enc:  "0000000000000000000000000000000000000000000000000001000000000001",
    84  		want: false,
    85  		err:  "abi: improperly encoded boolean value",
    86  	},
    87  	{
    88  		def:  `[{ "type": "bool" }]`,
    89  		enc:  "0000000000000000000000000000000000000000000000000000000000000003",
    90  		want: false,
    91  		err:  "abi: improperly encoded boolean value",
    92  	},
    93  	// Integers
    94  	{
    95  		def:  `[{"type": "uint32"}]`,
    96  		enc:  "0000000000000000000000000000000000000000000000000000000000000001",
    97  		want: uint16(0),
    98  		err:  "abi: cannot unmarshal uint32 in to uint16",
    99  	},
   100  	{
   101  		def:  `[{"type": "uint17"}]`,
   102  		enc:  "0000000000000000000000000000000000000000000000000000000000000001",
   103  		want: uint16(0),
   104  		err:  "abi: cannot unmarshal *big.Int in to uint16",
   105  	},
   106  	{
   107  		def:  `[{"type": "int32"}]`,
   108  		enc:  "0000000000000000000000000000000000000000000000000000000000000001",
   109  		want: int16(0),
   110  		err:  "abi: cannot unmarshal int32 in to int16",
   111  	},
   112  	{
   113  		def:  `[{"type": "int17"}]`,
   114  		enc:  "0000000000000000000000000000000000000000000000000000000000000001",
   115  		want: int16(0),
   116  		err:  "abi: cannot unmarshal *big.Int in to int16",
   117  	},
   118  	{
   119  		def:  `[{"type": "bytes"}]`,
   120  		enc:  "000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000200100000000000000000000000000000000000000000000000000000000000000",
   121  		want: [32]byte{1},
   122  	},
   123  	{
   124  		def:  `[{"type": "bytes32"}]`,
   125  		enc:  "000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000200100000000000000000000000000000000000000000000000000000000000000",
   126  		want: []byte(nil),
   127  		err:  "abi: cannot unmarshal [32]uint8 in to []uint8",
   128  	},
   129  	{
   130  		def: `[{"name":"___","type":"int256"}]`,
   131  		enc: "00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002",
   132  		want: struct {
   133  			IntOne *big.Int
   134  			Intone *big.Int
   135  		}{IntOne: big.NewInt(1)},
   136  	},
   137  	{
   138  		def: `[{"name":"int_one","type":"int256"},{"name":"IntOne","type":"int256"}]`,
   139  		enc: "00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002",
   140  		want: struct {
   141  			Int1 *big.Int
   142  			Int2 *big.Int
   143  		}{},
   144  		err: "abi: multiple outputs mapping to the same struct field 'IntOne'",
   145  	},
   146  	{
   147  		def: `[{"name":"int","type":"int256"},{"name":"Int","type":"int256"}]`,
   148  		enc: "00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002",
   149  		want: struct {
   150  			Int1 *big.Int
   151  			Int2 *big.Int
   152  		}{},
   153  		err: "abi: multiple outputs mapping to the same struct field 'Int'",
   154  	},
   155  	{
   156  		def: `[{"name":"int","type":"int256"},{"name":"_int","type":"int256"}]`,
   157  		enc: "00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002",
   158  		want: struct {
   159  			Int1 *big.Int
   160  			Int2 *big.Int
   161  		}{},
   162  		err: "abi: multiple outputs mapping to the same struct field 'Int'",
   163  	},
   164  	{
   165  		def: `[{"name":"Int","type":"int256"},{"name":"_int","type":"int256"}]`,
   166  		enc: "00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002",
   167  		want: struct {
   168  			Int1 *big.Int
   169  			Int2 *big.Int
   170  		}{},
   171  		err: "abi: multiple outputs mapping to the same struct field 'Int'",
   172  	},
   173  	{
   174  		def: `[{"name":"Int","type":"int256"},{"name":"_","type":"int256"}]`,
   175  		enc: "00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002",
   176  		want: struct {
   177  			Int1 *big.Int
   178  			Int2 *big.Int
   179  		}{},
   180  		err: "abi: purely underscored output cannot unpack to struct",
   181  	},
   182  	// Make sure only the first argument is consumed
   183  	{
   184  		def: `[{"name":"int_one","type":"int256"}]`,
   185  		enc: "00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002",
   186  		want: struct {
   187  			IntOne *big.Int
   188  		}{big.NewInt(1)},
   189  	},
   190  	{
   191  		def: `[{"name":"int__one","type":"int256"}]`,
   192  		enc: "00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002",
   193  		want: struct {
   194  			IntOne *big.Int
   195  		}{big.NewInt(1)},
   196  	},
   197  	{
   198  		def: `[{"name":"int_one_","type":"int256"}]`,
   199  		enc: "00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002",
   200  		want: struct {
   201  			IntOne *big.Int
   202  		}{big.NewInt(1)},
   203  	},
   204  }
   205  
   206  // TestLocalUnpackTests runs test specially designed only for unpacking.
   207  // All test cases that can be used to test packing and unpacking should move to packing_test.go
   208  func TestLocalUnpackTests(t *testing.T) {
   209  	for i, test := range unpackTests {
   210  		t.Run(strconv.Itoa(i), func(t *testing.T) {
   211  			//Unpack
   212  			def := fmt.Sprintf(`[{ "name" : "method", "type": "function", "outputs": %s}]`, test.def)
   213  			abi, err := JSON(strings.NewReader(def))
   214  			if err != nil {
   215  				t.Fatalf("invalid ABI definition %s: %v", def, err)
   216  			}
   217  			encb, err := hex.DecodeString(test.enc)
   218  			if err != nil {
   219  				t.Fatalf("invalid hex %s: %v", test.enc, err)
   220  			}
   221  			outptr := reflect.New(reflect.TypeOf(test.want))
   222  			err = abi.UnpackIntoInterface(outptr.Interface(), "method", encb)
   223  			if err := test.checkError(err); err != nil {
   224  				t.Errorf("test %d (%v) failed: %v", i, test.def, err)
   225  				return
   226  			}
   227  			out := outptr.Elem().Interface()
   228  			if !reflect.DeepEqual(test.want, out) {
   229  				t.Errorf("test %d (%v) failed: expected %v, got %v", i, test.def, test.want, out)
   230  			}
   231  		})
   232  	}
   233  }
   234  
   235  func TestUnpackIntoInterfaceSetDynamicArrayOutput(t *testing.T) {
   236  	abi, err := JSON(strings.NewReader(`[{"constant":true,"inputs":[],"name":"testDynamicFixedBytes15","outputs":[{"name":"","type":"bytes15[]"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"testDynamicFixedBytes32","outputs":[{"name":"","type":"bytes32[]"}],"payable":false,"stateMutability":"view","type":"function"}]`))
   237  	if err != nil {
   238  		t.Fatal(err)
   239  	}
   240  
   241  	var (
   242  		marshalledReturn32 = common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000230783132333435363738393000000000000000000000000000000000000000003078303938373635343332310000000000000000000000000000000000000000")
   243  		marshalledReturn15 = common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000230783031323334350000000000000000000000000000000000000000000000003078393837363534000000000000000000000000000000000000000000000000")
   244  
   245  		out32 [][32]byte
   246  		out15 [][15]byte
   247  	)
   248  
   249  	// test 32
   250  	err = abi.UnpackIntoInterface(&out32, "testDynamicFixedBytes32", marshalledReturn32)
   251  	if err != nil {
   252  		t.Fatal(err)
   253  	}
   254  	if len(out32) != 2 {
   255  		t.Fatalf("expected array with 2 values, got %d", len(out32))
   256  	}
   257  	expected := common.Hex2Bytes("3078313233343536373839300000000000000000000000000000000000000000")
   258  	if !bytes.Equal(out32[0][:], expected) {
   259  		t.Errorf("expected %x, got %x\n", expected, out32[0])
   260  	}
   261  	expected = common.Hex2Bytes("3078303938373635343332310000000000000000000000000000000000000000")
   262  	if !bytes.Equal(out32[1][:], expected) {
   263  		t.Errorf("expected %x, got %x\n", expected, out32[1])
   264  	}
   265  
   266  	// test 15
   267  	err = abi.UnpackIntoInterface(&out15, "testDynamicFixedBytes32", marshalledReturn15)
   268  	if err != nil {
   269  		t.Fatal(err)
   270  	}
   271  	if len(out15) != 2 {
   272  		t.Fatalf("expected array with 2 values, got %d", len(out15))
   273  	}
   274  	expected = common.Hex2Bytes("307830313233343500000000000000")
   275  	if !bytes.Equal(out15[0][:], expected) {
   276  		t.Errorf("expected %x, got %x\n", expected, out15[0])
   277  	}
   278  	expected = common.Hex2Bytes("307839383736353400000000000000")
   279  	if !bytes.Equal(out15[1][:], expected) {
   280  		t.Errorf("expected %x, got %x\n", expected, out15[1])
   281  	}
   282  }
   283  
   284  type methodMultiOutput struct {
   285  	Int    *big.Int
   286  	String string
   287  }
   288  
   289  func methodMultiReturn(require *require.Assertions) (ABI, []byte, methodMultiOutput) {
   290  	const definition = `[
   291  	{ "name" : "multi", "type": "function", "outputs": [ { "name": "Int", "type": "uint256" }, { "name": "String", "type": "string" } ] }]`
   292  	var expected = methodMultiOutput{big.NewInt(1), "hello"}
   293  
   294  	abi, err := JSON(strings.NewReader(definition))
   295  	require.NoError(err)
   296  	// using buff to make the code readable
   297  	buff := new(bytes.Buffer)
   298  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001"))
   299  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000040"))
   300  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000005"))
   301  	buff.Write(common.RightPadBytes([]byte(expected.String), 32))
   302  	return abi, buff.Bytes(), expected
   303  }
   304  
   305  func TestMethodMultiReturn(t *testing.T) {
   306  	type reversed struct {
   307  		String string
   308  		Int    *big.Int
   309  	}
   310  
   311  	newInterfaceSlice := func(len int) interface{} {
   312  		slice := make([]interface{}, len)
   313  		return &slice
   314  	}
   315  
   316  	abi, data, expected := methodMultiReturn(require.New(t))
   317  	bigint := new(big.Int)
   318  	var testCases = []struct {
   319  		dest     interface{}
   320  		expected interface{}
   321  		error    string
   322  		name     string
   323  	}{{
   324  		&methodMultiOutput{},
   325  		&expected,
   326  		"",
   327  		"Can unpack into structure",
   328  	}, {
   329  		&reversed{},
   330  		&reversed{expected.String, expected.Int},
   331  		"",
   332  		"Can unpack into reversed structure",
   333  	}, {
   334  		&[]interface{}{&bigint, new(string)},
   335  		&[]interface{}{&expected.Int, &expected.String},
   336  		"",
   337  		"Can unpack into a slice",
   338  	}, {
   339  		&[2]interface{}{&bigint, new(string)},
   340  		&[2]interface{}{&expected.Int, &expected.String},
   341  		"",
   342  		"Can unpack into an array",
   343  	}, {
   344  		&[2]interface{}{},
   345  		&[2]interface{}{expected.Int, expected.String},
   346  		"",
   347  		"Can unpack into interface array",
   348  	}, {
   349  		newInterfaceSlice(2),
   350  		&[]interface{}{expected.Int, expected.String},
   351  		"",
   352  		"Can unpack into interface slice",
   353  	}, {
   354  		&[]interface{}{new(int), new(int)},
   355  		&[]interface{}{&expected.Int, &expected.String},
   356  		"abi: cannot unmarshal *big.Int in to int",
   357  		"Can not unpack into a slice with wrong types",
   358  	}, {
   359  		&[]interface{}{new(int)},
   360  		&[]interface{}{},
   361  		"abi: insufficient number of arguments for unpack, want 2, got 1",
   362  		"Can not unpack into a slice with wrong types",
   363  	}}
   364  	for _, tc := range testCases {
   365  		tc := tc
   366  		t.Run(tc.name, func(t *testing.T) {
   367  			require := require.New(t)
   368  			err := abi.UnpackIntoInterface(tc.dest, "multi", data)
   369  			if tc.error == "" {
   370  				require.Nil(err, "Should be able to unpack method outputs.")
   371  				require.Equal(tc.expected, tc.dest)
   372  			} else {
   373  				require.EqualError(err, tc.error)
   374  			}
   375  		})
   376  	}
   377  }
   378  
   379  func TestMultiReturnWithArray(t *testing.T) {
   380  	const definition = `[{"name" : "multi", "type": "function", "outputs": [{"type": "uint64[3]"}, {"type": "uint64"}]}]`
   381  	abi, err := JSON(strings.NewReader(definition))
   382  	if err != nil {
   383  		t.Fatal(err)
   384  	}
   385  	buff := new(bytes.Buffer)
   386  	buff.Write(common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000900000000000000000000000000000000000000000000000000000000000000090000000000000000000000000000000000000000000000000000000000000009"))
   387  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000008"))
   388  
   389  	ret1, ret1Exp := new([3]uint64), [3]uint64{9, 9, 9}
   390  	ret2, ret2Exp := new(uint64), uint64(8)
   391  	if err := abi.UnpackIntoInterface(&[]interface{}{ret1, ret2}, "multi", buff.Bytes()); err != nil {
   392  		t.Fatal(err)
   393  	}
   394  	if !reflect.DeepEqual(*ret1, ret1Exp) {
   395  		t.Error("array result", *ret1, "!= Expected", ret1Exp)
   396  	}
   397  	if *ret2 != ret2Exp {
   398  		t.Error("int result", *ret2, "!= Expected", ret2Exp)
   399  	}
   400  }
   401  
   402  func TestMultiReturnWithStringArray(t *testing.T) {
   403  	const definition = `[{"name" : "multi", "type": "function", "outputs": [{"name": "","type": "uint256[3]"},{"name": "","type": "address"},{"name": "","type": "string[2]"},{"name": "","type": "bool"}]}]`
   404  	abi, err := JSON(strings.NewReader(definition))
   405  	if err != nil {
   406  		t.Fatal(err)
   407  	}
   408  	buff := new(bytes.Buffer)
   409  	buff.Write(common.Hex2Bytes("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"))
   410  	temp, _ := big.NewInt(0).SetString("30000000000000000000", 10)
   411  	ret1, ret1Exp := new([3]*big.Int), [3]*big.Int{big.NewInt(1545304298), big.NewInt(6), temp}
   412  	ret2, ret2Exp := new(common.Address), common.HexToAddress("ab1257528b3782fb40d7ed5f72e624b744dffb2f")
   413  	ret3, ret3Exp := new([2]string), [2]string{"Ethereum", "Hello, Ethereum!"}
   414  	ret4, ret4Exp := new(bool), false
   415  	if err := abi.UnpackIntoInterface(&[]interface{}{ret1, ret2, ret3, ret4}, "multi", buff.Bytes()); err != nil {
   416  		t.Fatal(err)
   417  	}
   418  	if !reflect.DeepEqual(*ret1, ret1Exp) {
   419  		t.Error("big.Int array result", *ret1, "!= Expected", ret1Exp)
   420  	}
   421  	if !reflect.DeepEqual(*ret2, ret2Exp) {
   422  		t.Error("address result", *ret2, "!= Expected", ret2Exp)
   423  	}
   424  	if !reflect.DeepEqual(*ret3, ret3Exp) {
   425  		t.Error("string array result", *ret3, "!= Expected", ret3Exp)
   426  	}
   427  	if !reflect.DeepEqual(*ret4, ret4Exp) {
   428  		t.Error("bool result", *ret4, "!= Expected", ret4Exp)
   429  	}
   430  }
   431  
   432  func TestMultiReturnWithStringSlice(t *testing.T) {
   433  	const definition = `[{"name" : "multi", "type": "function", "outputs": [{"name": "","type": "string[]"},{"name": "","type": "uint256[]"}]}]`
   434  	abi, err := JSON(strings.NewReader(definition))
   435  	if err != nil {
   436  		t.Fatal(err)
   437  	}
   438  	buff := new(bytes.Buffer)
   439  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000040")) // output[0] offset
   440  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000120")) // output[1] offset
   441  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002")) // output[0] length
   442  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000040")) // output[0][0] offset
   443  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000080")) // output[0][1] offset
   444  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000008")) // output[0][0] length
   445  	buff.Write(common.Hex2Bytes("657468657265756d000000000000000000000000000000000000000000000000")) // output[0][0] value
   446  	buff.Write(common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000b")) // output[0][1] length
   447  	buff.Write(common.Hex2Bytes("676f2d657468657265756d000000000000000000000000000000000000000000")) // output[0][1] value
   448  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002")) // output[1] length
   449  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000064")) // output[1][0] value
   450  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000065")) // output[1][1] value
   451  	ret1, ret1Exp := new([]string), []string{"ethereum", "go-ethereum"}
   452  	ret2, ret2Exp := new([]*big.Int), []*big.Int{big.NewInt(100), big.NewInt(101)}
   453  	if err := abi.UnpackIntoInterface(&[]interface{}{ret1, ret2}, "multi", buff.Bytes()); err != nil {
   454  		t.Fatal(err)
   455  	}
   456  	if !reflect.DeepEqual(*ret1, ret1Exp) {
   457  		t.Error("string slice result", *ret1, "!= Expected", ret1Exp)
   458  	}
   459  	if !reflect.DeepEqual(*ret2, ret2Exp) {
   460  		t.Error("uint256 slice result", *ret2, "!= Expected", ret2Exp)
   461  	}
   462  }
   463  
   464  func TestMultiReturnWithDeeplyNestedArray(t *testing.T) {
   465  	// Similar to TestMultiReturnWithArray, but with a special case in mind:
   466  	//  values of nested static arrays count towards the size as well, and any element following
   467  	//  after such nested array argument should be read with the correct offset,
   468  	//  so that it does not read content from the previous array argument.
   469  	const definition = `[{"name" : "multi", "type": "function", "outputs": [{"type": "uint64[3][2][4]"}, {"type": "uint64"}]}]`
   470  	abi, err := JSON(strings.NewReader(definition))
   471  	if err != nil {
   472  		t.Fatal(err)
   473  	}
   474  	buff := new(bytes.Buffer)
   475  	// construct the test array, each 3 char element is joined with 61 '0' chars,
   476  	// to from the ((3 + 61) * 0.5) = 32 byte elements in the array.
   477  	buff.Write(common.Hex2Bytes(strings.Join([]string{
   478  		"", //empty, to apply the 61-char separator to the first element as well.
   479  		"111", "112", "113", "121", "122", "123",
   480  		"211", "212", "213", "221", "222", "223",
   481  		"311", "312", "313", "321", "322", "323",
   482  		"411", "412", "413", "421", "422", "423",
   483  	}, "0000000000000000000000000000000000000000000000000000000000000")))
   484  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000009876"))
   485  
   486  	ret1, ret1Exp := new([4][2][3]uint64), [4][2][3]uint64{
   487  		{{0x111, 0x112, 0x113}, {0x121, 0x122, 0x123}},
   488  		{{0x211, 0x212, 0x213}, {0x221, 0x222, 0x223}},
   489  		{{0x311, 0x312, 0x313}, {0x321, 0x322, 0x323}},
   490  		{{0x411, 0x412, 0x413}, {0x421, 0x422, 0x423}},
   491  	}
   492  	ret2, ret2Exp := new(uint64), uint64(0x9876)
   493  	if err := abi.UnpackIntoInterface(&[]interface{}{ret1, ret2}, "multi", buff.Bytes()); err != nil {
   494  		t.Fatal(err)
   495  	}
   496  	if !reflect.DeepEqual(*ret1, ret1Exp) {
   497  		t.Error("array result", *ret1, "!= Expected", ret1Exp)
   498  	}
   499  	if *ret2 != ret2Exp {
   500  		t.Error("int result", *ret2, "!= Expected", ret2Exp)
   501  	}
   502  }
   503  
   504  func TestUnmarshal(t *testing.T) {
   505  	const definition = `[
   506  	{ "name" : "int", "type": "function", "outputs": [ { "type": "uint256" } ] },
   507  	{ "name" : "bool", "type": "function", "outputs": [ { "type": "bool" } ] },
   508  	{ "name" : "bytes", "type": "function", "outputs": [ { "type": "bytes" } ] },
   509  	{ "name" : "fixed", "type": "function", "outputs": [ { "type": "bytes32" } ] },
   510  	{ "name" : "multi", "type": "function", "outputs": [ { "type": "bytes" }, { "type": "bytes" } ] },
   511  	{ "name" : "intArraySingle", "type": "function", "outputs": [ { "type": "uint256[3]" } ] },
   512  	{ "name" : "addressSliceSingle", "type": "function", "outputs": [ { "type": "address[]" } ] },
   513  	{ "name" : "addressSliceDouble", "type": "function", "outputs": [ { "name": "a", "type": "address[]" }, { "name": "b", "type": "address[]" } ] },
   514  	{ "name" : "mixedBytes", "type": "function", "stateMutability" : "view", "outputs": [ { "name": "a", "type": "bytes" }, { "name": "b", "type": "bytes32" } ] }]`
   515  
   516  	abi, err := JSON(strings.NewReader(definition))
   517  	if err != nil {
   518  		t.Fatal(err)
   519  	}
   520  	buff := new(bytes.Buffer)
   521  
   522  	// marshall mixed bytes (mixedBytes)
   523  	p0, p0Exp := []byte{}, common.Hex2Bytes("01020000000000000000")
   524  	p1, p1Exp := [32]byte{}, common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000ddeeff")
   525  	mixedBytes := []interface{}{&p0, &p1}
   526  
   527  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000040"))
   528  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000ddeeff"))
   529  	buff.Write(common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000a"))
   530  	buff.Write(common.Hex2Bytes("0102000000000000000000000000000000000000000000000000000000000000"))
   531  
   532  	err = abi.UnpackIntoInterface(&mixedBytes, "mixedBytes", buff.Bytes())
   533  	if err != nil {
   534  		t.Error(err)
   535  	} else {
   536  		if !bytes.Equal(p0, p0Exp) {
   537  			t.Errorf("unexpected value unpacked: want %x, got %x", p0Exp, p0)
   538  		}
   539  
   540  		if !bytes.Equal(p1[:], p1Exp) {
   541  			t.Errorf("unexpected value unpacked: want %x, got %x", p1Exp, p1)
   542  		}
   543  	}
   544  
   545  	// marshal int
   546  	var Int *big.Int
   547  	err = abi.UnpackIntoInterface(&Int, "int", common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001"))
   548  	if err != nil {
   549  		t.Error(err)
   550  	}
   551  
   552  	if Int == nil || Int.Cmp(big.NewInt(1)) != 0 {
   553  		t.Error("expected Int to be 1 got", Int)
   554  	}
   555  
   556  	// marshal bool
   557  	var Bool bool
   558  	err = abi.UnpackIntoInterface(&Bool, "bool", common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001"))
   559  	if err != nil {
   560  		t.Error(err)
   561  	}
   562  
   563  	if !Bool {
   564  		t.Error("expected Bool to be true")
   565  	}
   566  
   567  	// marshal dynamic bytes max length 32
   568  	buff.Reset()
   569  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000020"))
   570  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000020"))
   571  	bytesOut := common.RightPadBytes([]byte("hello"), 32)
   572  	buff.Write(bytesOut)
   573  
   574  	var Bytes []byte
   575  	err = abi.UnpackIntoInterface(&Bytes, "bytes", buff.Bytes())
   576  	if err != nil {
   577  		t.Error(err)
   578  	}
   579  
   580  	if !bytes.Equal(Bytes, bytesOut) {
   581  		t.Errorf("expected %x got %x", bytesOut, Bytes)
   582  	}
   583  
   584  	// marshall dynamic bytes max length 64
   585  	buff.Reset()
   586  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000020"))
   587  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000040"))
   588  	bytesOut = common.RightPadBytes([]byte("hello"), 64)
   589  	buff.Write(bytesOut)
   590  
   591  	err = abi.UnpackIntoInterface(&Bytes, "bytes", buff.Bytes())
   592  	if err != nil {
   593  		t.Error(err)
   594  	}
   595  
   596  	if !bytes.Equal(Bytes, bytesOut) {
   597  		t.Errorf("expected %x got %x", bytesOut, Bytes)
   598  	}
   599  
   600  	// marshall dynamic bytes max length 64
   601  	buff.Reset()
   602  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000020"))
   603  	buff.Write(common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000003f"))
   604  	bytesOut = common.RightPadBytes([]byte("hello"), 64)
   605  	buff.Write(bytesOut)
   606  
   607  	err = abi.UnpackIntoInterface(&Bytes, "bytes", buff.Bytes())
   608  	if err != nil {
   609  		t.Error(err)
   610  	}
   611  
   612  	if !bytes.Equal(Bytes, bytesOut[:len(bytesOut)-1]) {
   613  		t.Errorf("expected %x got %x", bytesOut[:len(bytesOut)-1], Bytes)
   614  	}
   615  
   616  	// marshal dynamic bytes output empty
   617  	err = abi.UnpackIntoInterface(&Bytes, "bytes", nil)
   618  	if err == nil {
   619  		t.Error("expected error")
   620  	}
   621  
   622  	// marshal dynamic bytes length 5
   623  	buff.Reset()
   624  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000020"))
   625  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000005"))
   626  	buff.Write(common.RightPadBytes([]byte("hello"), 32))
   627  
   628  	err = abi.UnpackIntoInterface(&Bytes, "bytes", buff.Bytes())
   629  	if err != nil {
   630  		t.Error(err)
   631  	}
   632  
   633  	if !bytes.Equal(Bytes, []byte("hello")) {
   634  		t.Errorf("expected %x got %x", bytesOut, Bytes)
   635  	}
   636  
   637  	// marshal dynamic bytes length 5
   638  	buff.Reset()
   639  	buff.Write(common.RightPadBytes([]byte("hello"), 32))
   640  
   641  	var hash common.Hash
   642  	err = abi.UnpackIntoInterface(&hash, "fixed", buff.Bytes())
   643  	if err != nil {
   644  		t.Error(err)
   645  	}
   646  
   647  	helloHash := common.BytesToHash(common.RightPadBytes([]byte("hello"), 32))
   648  	if hash != helloHash {
   649  		t.Errorf("Expected %x to equal %x", hash, helloHash)
   650  	}
   651  
   652  	// marshal error
   653  	buff.Reset()
   654  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000020"))
   655  	err = abi.UnpackIntoInterface(&Bytes, "bytes", buff.Bytes())
   656  	if err == nil {
   657  		t.Error("expected error")
   658  	}
   659  
   660  	err = abi.UnpackIntoInterface(&Bytes, "multi", make([]byte, 64))
   661  	if err == nil {
   662  		t.Error("expected error")
   663  	}
   664  
   665  	buff.Reset()
   666  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001"))
   667  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002"))
   668  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000003"))
   669  	// marshal int array
   670  	var intArray [3]*big.Int
   671  	err = abi.UnpackIntoInterface(&intArray, "intArraySingle", buff.Bytes())
   672  	if err != nil {
   673  		t.Error(err)
   674  	}
   675  	var testAgainstIntArray [3]*big.Int
   676  	testAgainstIntArray[0] = big.NewInt(1)
   677  	testAgainstIntArray[1] = big.NewInt(2)
   678  	testAgainstIntArray[2] = big.NewInt(3)
   679  
   680  	for i, Int := range intArray {
   681  		if Int.Cmp(testAgainstIntArray[i]) != 0 {
   682  			t.Errorf("expected %v, got %v", testAgainstIntArray[i], Int)
   683  		}
   684  	}
   685  	// marshal address slice
   686  	buff.Reset()
   687  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000020")) // offset
   688  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001")) // size
   689  	buff.Write(common.Hex2Bytes("0000000000000000000000000100000000000000000000000000000000000000"))
   690  
   691  	var outAddr []common.Address
   692  	err = abi.UnpackIntoInterface(&outAddr, "addressSliceSingle", buff.Bytes())
   693  	if err != nil {
   694  		t.Fatal("didn't expect error:", err)
   695  	}
   696  
   697  	if len(outAddr) != 1 {
   698  		t.Fatal("expected 1 item, got", len(outAddr))
   699  	}
   700  
   701  	if outAddr[0] != (common.Address{1}) {
   702  		t.Errorf("expected %x, got %x", common.Address{1}, outAddr[0])
   703  	}
   704  
   705  	// marshal multiple address slice
   706  	buff.Reset()
   707  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000040")) // offset
   708  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000080")) // offset
   709  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001")) // size
   710  	buff.Write(common.Hex2Bytes("0000000000000000000000000100000000000000000000000000000000000000"))
   711  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002")) // size
   712  	buff.Write(common.Hex2Bytes("0000000000000000000000000200000000000000000000000000000000000000"))
   713  	buff.Write(common.Hex2Bytes("0000000000000000000000000300000000000000000000000000000000000000"))
   714  
   715  	var outAddrStruct struct {
   716  		A []common.Address
   717  		B []common.Address
   718  	}
   719  	err = abi.UnpackIntoInterface(&outAddrStruct, "addressSliceDouble", buff.Bytes())
   720  	if err != nil {
   721  		t.Fatal("didn't expect error:", err)
   722  	}
   723  
   724  	if len(outAddrStruct.A) != 1 {
   725  		t.Fatal("expected 1 item, got", len(outAddrStruct.A))
   726  	}
   727  
   728  	if outAddrStruct.A[0] != (common.Address{1}) {
   729  		t.Errorf("expected %x, got %x", common.Address{1}, outAddrStruct.A[0])
   730  	}
   731  
   732  	if len(outAddrStruct.B) != 2 {
   733  		t.Fatal("expected 1 item, got", len(outAddrStruct.B))
   734  	}
   735  
   736  	if outAddrStruct.B[0] != (common.Address{2}) {
   737  		t.Errorf("expected %x, got %x", common.Address{2}, outAddrStruct.B[0])
   738  	}
   739  	if outAddrStruct.B[1] != (common.Address{3}) {
   740  		t.Errorf("expected %x, got %x", common.Address{3}, outAddrStruct.B[1])
   741  	}
   742  
   743  	// marshal invalid address slice
   744  	buff.Reset()
   745  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000100"))
   746  
   747  	err = abi.UnpackIntoInterface(&outAddr, "addressSliceSingle", buff.Bytes())
   748  	if err == nil {
   749  		t.Fatal("expected error:", err)
   750  	}
   751  }
   752  
   753  func TestUnpackTuple(t *testing.T) {
   754  	const simpleTuple = `[{"name":"tuple","type":"function","outputs":[{"type":"tuple","name":"ret","components":[{"type":"int256","name":"a"},{"type":"int256","name":"b"}]}]}]`
   755  	abi, err := JSON(strings.NewReader(simpleTuple))
   756  	if err != nil {
   757  		t.Fatal(err)
   758  	}
   759  	buff := new(bytes.Buffer)
   760  
   761  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001")) // ret[a] = 1
   762  	buff.Write(common.Hex2Bytes("ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff")) // ret[b] = -1
   763  
   764  	// If the result is single tuple, use struct as return value container directly.
   765  	type v struct {
   766  		A *big.Int
   767  		B *big.Int
   768  	}
   769  	type r struct {
   770  		Result v
   771  	}
   772  	var ret0 = new(r)
   773  	err = abi.UnpackIntoInterface(ret0, "tuple", buff.Bytes())
   774  
   775  	if err != nil {
   776  		t.Error(err)
   777  	} else {
   778  		if ret0.Result.A.Cmp(big.NewInt(1)) != 0 {
   779  			t.Errorf("unexpected value unpacked: want %x, got %x", 1, ret0.Result.A)
   780  		}
   781  		if ret0.Result.B.Cmp(big.NewInt(-1)) != 0 {
   782  			t.Errorf("unexpected value unpacked: want %x, got %x", -1, ret0.Result.B)
   783  		}
   784  	}
   785  
   786  	// Test nested tuple
   787  	const nestedTuple = `[{"name":"tuple","type":"function","outputs":[
   788  		{"type":"tuple","name":"s","components":[{"type":"uint256","name":"a"},{"type":"uint256[]","name":"b"},{"type":"tuple[]","name":"c","components":[{"name":"x", "type":"uint256"},{"name":"y","type":"uint256"}]}]},
   789  		{"type":"tuple","name":"t","components":[{"name":"x", "type":"uint256"},{"name":"y","type":"uint256"}]},
   790  		{"type":"uint256","name":"a"}
   791  	]}]`
   792  
   793  	abi, err = JSON(strings.NewReader(nestedTuple))
   794  	if err != nil {
   795  		t.Fatal(err)
   796  	}
   797  	buff.Reset()
   798  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000080")) // s offset
   799  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000000")) // t.X = 0
   800  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001")) // t.Y = 1
   801  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001")) // a = 1
   802  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001")) // s.A = 1
   803  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000060")) // s.B offset
   804  	buff.Write(common.Hex2Bytes("00000000000000000000000000000000000000000000000000000000000000c0")) // s.C offset
   805  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002")) // s.B length
   806  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001")) // s.B[0] = 1
   807  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002")) // s.B[0] = 2
   808  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002")) // s.C length
   809  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001")) // s.C[0].X
   810  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002")) // s.C[0].Y
   811  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002")) // s.C[1].X
   812  	buff.Write(common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001")) // s.C[1].Y
   813  
   814  	type T struct {
   815  		X *big.Int `abi:"x"`
   816  		Z *big.Int `abi:"y"` // Test whether the abi tag works.
   817  	}
   818  
   819  	type S struct {
   820  		A *big.Int
   821  		B []*big.Int
   822  		C []T
   823  	}
   824  
   825  	type Ret struct {
   826  		FieldS S `abi:"s"`
   827  		FieldT T `abi:"t"`
   828  		A      *big.Int
   829  	}
   830  	var ret Ret
   831  	var expected = Ret{
   832  		FieldS: S{
   833  			A: big.NewInt(1),
   834  			B: []*big.Int{big.NewInt(1), big.NewInt(2)},
   835  			C: []T{
   836  				{big.NewInt(1), big.NewInt(2)},
   837  				{big.NewInt(2), big.NewInt(1)},
   838  			},
   839  		},
   840  		FieldT: T{
   841  			big.NewInt(0), big.NewInt(1),
   842  		},
   843  		A: big.NewInt(1),
   844  	}
   845  
   846  	err = abi.UnpackIntoInterface(&ret, "tuple", buff.Bytes())
   847  	if err != nil {
   848  		t.Error(err)
   849  	}
   850  	if reflect.DeepEqual(ret, expected) {
   851  		t.Error("unexpected unpack value")
   852  	}
   853  }
   854  
   855  func TestOOMMaliciousInput(t *testing.T) {
   856  	oomTests := []unpackTest{
   857  		{
   858  			def: `[{"type": "uint8[]"}]`,
   859  			enc: "0000000000000000000000000000000000000000000000000000000000000020" + // offset
   860  				"0000000000000000000000000000000000000000000000000000000000000003" + // num elems
   861  				"0000000000000000000000000000000000000000000000000000000000000001" + // elem 1
   862  				"0000000000000000000000000000000000000000000000000000000000000002", // elem 2
   863  		},
   864  		{ // Length larger than 64 bits
   865  			def: `[{"type": "uint8[]"}]`,
   866  			enc: "0000000000000000000000000000000000000000000000000000000000000020" + // offset
   867  				"00ffffffffffffffffffffffffffffffffffffffffffffff0000000000000002" + // num elems
   868  				"0000000000000000000000000000000000000000000000000000000000000001" + // elem 1
   869  				"0000000000000000000000000000000000000000000000000000000000000002", // elem 2
   870  		},
   871  		{ // Offset very large (over 64 bits)
   872  			def: `[{"type": "uint8[]"}]`,
   873  			enc: "00ffffffffffffffffffffffffffffffffffffffffffffff0000000000000020" + // offset
   874  				"0000000000000000000000000000000000000000000000000000000000000002" + // num elems
   875  				"0000000000000000000000000000000000000000000000000000000000000001" + // elem 1
   876  				"0000000000000000000000000000000000000000000000000000000000000002", // elem 2
   877  		},
   878  		{ // Offset very large (below 64 bits)
   879  			def: `[{"type": "uint8[]"}]`,
   880  			enc: "0000000000000000000000000000000000000000000000007ffffffffff00020" + // offset
   881  				"0000000000000000000000000000000000000000000000000000000000000002" + // num elems
   882  				"0000000000000000000000000000000000000000000000000000000000000001" + // elem 1
   883  				"0000000000000000000000000000000000000000000000000000000000000002", // elem 2
   884  		},
   885  		{ // Offset negative (as 64 bit)
   886  			def: `[{"type": "uint8[]"}]`,
   887  			enc: "000000000000000000000000000000000000000000000000f000000000000020" + // offset
   888  				"0000000000000000000000000000000000000000000000000000000000000002" + // num elems
   889  				"0000000000000000000000000000000000000000000000000000000000000001" + // elem 1
   890  				"0000000000000000000000000000000000000000000000000000000000000002", // elem 2
   891  		},
   892  
   893  		{ // Negative length
   894  			def: `[{"type": "uint8[]"}]`,
   895  			enc: "0000000000000000000000000000000000000000000000000000000000000020" + // offset
   896  				"000000000000000000000000000000000000000000000000f000000000000002" + // num elems
   897  				"0000000000000000000000000000000000000000000000000000000000000001" + // elem 1
   898  				"0000000000000000000000000000000000000000000000000000000000000002", // elem 2
   899  		},
   900  		{ // Very large length
   901  			def: `[{"type": "uint8[]"}]`,
   902  			enc: "0000000000000000000000000000000000000000000000000000000000000020" + // offset
   903  				"0000000000000000000000000000000000000000000000007fffffffff000002" + // num elems
   904  				"0000000000000000000000000000000000000000000000000000000000000001" + // elem 1
   905  				"0000000000000000000000000000000000000000000000000000000000000002", // elem 2
   906  		},
   907  	}
   908  	for i, test := range oomTests {
   909  		def := fmt.Sprintf(`[{ "name" : "method", "type": "function", "outputs": %s}]`, test.def)
   910  		abi, err := JSON(strings.NewReader(def))
   911  		if err != nil {
   912  			t.Fatalf("invalid ABI definition %s: %v", def, err)
   913  		}
   914  		encb, err := hex.DecodeString(test.enc)
   915  		if err != nil {
   916  			t.Fatalf("invalid hex: %s" + test.enc)
   917  		}
   918  		_, err = abi.Methods["method"].Outputs.UnpackValues(encb)
   919  		if err == nil {
   920  			t.Fatalf("Expected error on malicious input, test %d", i)
   921  		}
   922  	}
   923  }