fix: Handle MAX_INT_256 (#9511)

Change maxBitLen of sdk.Int to handle max Erc20 value.

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## Description

Closes: #XXXX

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---

### Author Checklist

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please add links to any relevant follow up issues.*

I have...

- [x] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] added `!` to the type prefix if API or client breaking change
- [x] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing)
- [x] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
- [ ] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

### Reviewers Checklist

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your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed 
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

CHANGELOG.md

@@ -139,6 +139,7 @@ if input key is empty, or input data contains empty key.
 * (x/slashing) [\#8427](https://github.com/cosmos/cosmos-sdk/pull/8427) Fix query signing infos command
 * (server) [\#8399](https://github.com/cosmos/cosmos-sdk/pull/8399) fix gRPC-web flag default value
 * (x/bank) [\#9229](https://github.com/cosmos/cosmos-sdk/pull/9229) Now zero coin balances cannot be added to balances & supply stores. If any denom becomes zero corresponding key gets deleted from store.
+* (types) [\#9511](https://github.com/cosmos/cosmos-sdk/pull/9511) Change `maxBitLen` of `sdk.Int` and `sdk.Dec`  to handle max ERC20 value.
 
 ### Deprecated
 

types/decimal.go

@@ -26,6 +26,8 @@ const (
 	// Ceiling[Log2[999 999 999 999 999 999]]
 	DecimalPrecisionBits = 60
 
+	maxDecBitLen = maxBitLen + DecimalPrecisionBits
+
 	// max number of iterations in ApproxRoot function
 	maxApproxRootIterations = 100
 )
@@ -222,7 +224,7 @@ func (d Dec) BigInt() *big.Int {
 func (d Dec) Add(d2 Dec) Dec {
 	res := new(big.Int).Add(d.i, d2.i)
 
-	if res.BitLen() > 255+DecimalPrecisionBits {
+	if res.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
 	return Dec{res}
@@ -232,7 +234,7 @@ func (d Dec) Add(d2 Dec) Dec {
 func (d Dec) Sub(d2 Dec) Dec {
 	res := new(big.Int).Sub(d.i, d2.i)
 
-	if res.BitLen() > 255+DecimalPrecisionBits {
+	if res.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
 	return Dec{res}
@@ -243,7 +245,7 @@ func (d Dec) Mul(d2 Dec) Dec {
 	mul := new(big.Int).Mul(d.i, d2.i)
 	chopped := chopPrecisionAndRound(mul)
 
-	if chopped.BitLen() > 255+DecimalPrecisionBits {
+	if chopped.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
 	return Dec{chopped}
@@ -254,7 +256,7 @@ func (d Dec) MulTruncate(d2 Dec) Dec {
 	mul := new(big.Int).Mul(d.i, d2.i)
 	chopped := chopPrecisionAndTruncate(mul)
 
-	if chopped.BitLen() > 255+DecimalPrecisionBits {
+	if chopped.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
 	return Dec{chopped}
@@ -264,7 +266,7 @@ func (d Dec) MulTruncate(d2 Dec) Dec {
 func (d Dec) MulInt(i Int) Dec {
 	mul := new(big.Int).Mul(d.i, i.i)
 
-	if mul.BitLen() > 255+DecimalPrecisionBits {
+	if mul.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
 	return Dec{mul}
@@ -274,7 +276,7 @@ func (d Dec) MulInt(i Int) Dec {
 func (d Dec) MulInt64(i int64) Dec {
 	mul := new(big.Int).Mul(d.i, big.NewInt(i))
 
-	if mul.BitLen() > 255+DecimalPrecisionBits {
+	if mul.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
 	return Dec{mul}
@@ -289,7 +291,7 @@ func (d Dec) Quo(d2 Dec) Dec {
 	quo := new(big.Int).Quo(mul, d2.i)
 	chopped := chopPrecisionAndRound(quo)
 
-	if chopped.BitLen() > 255+DecimalPrecisionBits {
+	if chopped.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
 	return Dec{chopped}
@@ -304,7 +306,7 @@ func (d Dec) QuoTruncate(d2 Dec) Dec {
 	quo := mul.Quo(mul, d2.i)
 	chopped := chopPrecisionAndTruncate(quo)
 
-	if chopped.BitLen() > 255+DecimalPrecisionBits {
+	if chopped.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
 	return Dec{chopped}
@@ -319,7 +321,7 @@ func (d Dec) QuoRoundUp(d2 Dec) Dec {
 	quo := new(big.Int).Quo(mul, d2.i)
 	chopped := chopPrecisionAndRoundUp(quo)
 
-	if chopped.BitLen() > 255+DecimalPrecisionBits {
+	if chopped.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
 	return Dec{chopped}

types/int.go

@@ -9,7 +9,7 @@ import (
 	"math/big"
 )
 
-const maxBitLen = 255
+const maxBitLen = 256
 
 func newIntegerFromString(s string) (*big.Int, bool) {
 	return new(big.Int).SetString(s, 0)
@@ -69,9 +69,9 @@ func unmarshalText(i *big.Int, text string) error {
 
 var _ CustomProtobufType = (*Int)(nil)
 
-// Int wraps big.Int with a 256 bit range bound
+// Int wraps big.Int with a 257 bit range bound
 // Checks overflow, underflow and division by zero
-// Exists in range from -(2^255 - 1) to 2^255 - 1
+// Exists in range from -(2^256 - 1) to 2^256 - 1
 type Int struct {
 	i *big.Int
 }

types/int_internal_test.go

@@ -63,7 +63,7 @@ func (s *internalIntTestSuite) TestEncodingRandom() {
 }
 
 func (s *internalIntTestSuite) TestSerializationOverflow() {
-	bx, _ := new(big.Int).SetString("91888242871839275229946405745257275988696311157297823662689937894645226298583", 10)
+	bx, _ := new(big.Int).SetString("115792089237316195423570985008687907853269984665640564039457584007913129639936", 10)
 	x := Int{bx}
 	y := new(Int)
 
@@ -80,6 +80,24 @@ func (s *internalIntTestSuite) TestSerializationOverflow() {
 	s.Require().Error(y.UnmarshalJSON(bz))
 }
 
+func (s *internalIntTestSuite) TestDeserializeMaxERC20() {
+	bx, _ := new(big.Int).SetString("115792089237316195423570985008687907853269984665640564039457584007913129639935", 10)
+	x := Int{bx}
+	y := new(Int)
+
+	bz, err := x.Marshal()
+	s.Require().NoError(err)
+
+	// require deserialization to be successful
+	s.Require().NoError(y.Unmarshal(bz))
+
+	// require JSON deserialization to succeed
+	bz, err = x.MarshalJSON()
+	s.Require().NoError(err)
+
+	s.Require().NoError(y.UnmarshalJSON(bz))
+}
+
 func (s *internalIntTestSuite) TestImmutabilityArithInt() {
 	size := 500
 

types/int_test.go

@@ -40,16 +40,16 @@ func (s *intTestSuite) TestFromUint64() {
 }
 
 func (s *intTestSuite) TestIntPanic() {
-	// Max Int = 2^255-1 = 5.789e+76
-	// Min Int = -(2^255-1) = -5.789e+76
-	s.Require().NotPanics(func() { sdk.NewIntWithDecimal(1, 76) })
-	i1 := sdk.NewIntWithDecimal(1, 76)
-	s.Require().NotPanics(func() { sdk.NewIntWithDecimal(2, 76) })
-	i2 := sdk.NewIntWithDecimal(2, 76)
-	s.Require().NotPanics(func() { sdk.NewIntWithDecimal(3, 76) })
-	i3 := sdk.NewIntWithDecimal(3, 76)
-
-	s.Require().Panics(func() { sdk.NewIntWithDecimal(6, 76) })
+	// Max Int = 2^256-1 = 1.1579209e+77
+	// Min Int = -(2^256-1) = -1.1579209e+77
+	s.Require().NotPanics(func() { sdk.NewIntWithDecimal(4, 76) })
+	i1 := sdk.NewIntWithDecimal(4, 76)
+	s.Require().NotPanics(func() { sdk.NewIntWithDecimal(5, 76) })
+	i2 := sdk.NewIntWithDecimal(5, 76)
+	s.Require().NotPanics(func() { sdk.NewIntWithDecimal(6, 76) })
+	i3 := sdk.NewIntWithDecimal(6, 76)
+
+	s.Require().Panics(func() { sdk.NewIntWithDecimal(2, 77) })
 	s.Require().Panics(func() { sdk.NewIntWithDecimal(9, 80) })
 
 	// Overflow check
@@ -69,7 +69,7 @@ func (s *intTestSuite) TestIntPanic() {
 	s.Require().Panics(func() { i2.Neg().Mul(i2.Neg()) })
 	s.Require().Panics(func() { i3.Neg().Mul(i3.Neg()) })
 
-	// Underflow check
+	// // Underflow check
 	i3n := i3.Neg()
 	s.Require().NotPanics(func() { i3n.Sub(i1) })
 	s.Require().NotPanics(func() { i3n.Sub(i2) })
@@ -84,7 +84,7 @@ func (s *intTestSuite) TestIntPanic() {
 	s.Require().Panics(func() { i3.Mul(i3.Neg()) })
 
 	// Bound check
-	intmax := sdk.NewIntFromBigInt(new(big.Int).Sub(new(big.Int).Exp(big.NewInt(2), big.NewInt(255), nil), big.NewInt(1)))
+	intmax := sdk.NewIntFromBigInt(new(big.Int).Sub(new(big.Int).Exp(big.NewInt(2), big.NewInt(256), nil), big.NewInt(1)))
 	intmin := intmax.Neg()
 	s.Require().NotPanics(func() { intmax.Add(sdk.ZeroInt()) })
 	s.Require().NotPanics(func() { intmin.Sub(sdk.ZeroInt()) })