R4R: General Sanitization & Gas Cost Review

PENDING.md

@@ -92,6 +92,8 @@ IMPROVEMENTS
  * \#2509 Sanitize all usage of Dec.RoundInt64()
  * [\#556](https://github.com/cosmos/cosmos-sdk/issues/556) Increase `BaseApp`
  test coverage.
+ * [\#3552](https://github.com/cosmos/cosmos-sdk/pull/3552) Validate bit length when
+ deserializing `Int` types.
 
 * Tendermint
 

types/int.go

@@ -2,12 +2,15 @@ package types
 
 import (
  "encoding/json"
+ "fmt"
  "testing"
 
  "math/big"
  "math/rand"
 )
 
+const maxBitLen = 255
+
 func newIntegerFromString(s string) (*big.Int, bool) {
  return new(big.Int).SetString(s, 0)
 }
@@ -54,9 +57,21 @@ func marshalAmino(i *big.Int) (string, error) {
  return string(bz), err
 }
 
+func unmarshalText(i *big.Int, text string) error {
+ if err := i.UnmarshalText([]byte(text)); err != nil {
+ return err
+ }
+
+ if i.BitLen() > maxBitLen {
+ return fmt.Errorf("integer out of range: %s", text)
+ }
+
+ return nil
+}
+
 // UnmarshalAmino for custom decoding scheme
 func unmarshalAmino(i *big.Int, text string) (err error) {
- return i.UnmarshalText([]byte(text))
+ return unmarshalText(i, text)
 }
 
 // MarshalJSON for custom encoding scheme
@@ -77,12 +92,13 @@ func unmarshalJSON(i *big.Int, bz []byte) error {
  if err != nil {
  return err
  }
- return i.UnmarshalText([]byte(text))
+
+ return unmarshalText(i, text)
 }
 
 // Int wraps integer with 256 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^maxBitLen-1) to 2^maxBitLen-1
 type Int struct {
  i *big.Int
 }
@@ -99,7 +115,7 @@ func NewInt(n int64) Int {
 
 // NewIntFromBigInt constructs Int from big.Int
 func NewIntFromBigInt(i *big.Int) Int {
- if i.BitLen() > 255 {
+ if i.BitLen() > maxBitLen {
  panic("NewIntFromBigInt() out of bound")
  }
  return Int{i}
@@ -112,7 +128,7 @@ func NewIntFromString(s string) (res Int, ok bool) {
  return
  }
  // Check overflow
- if i.BitLen() > 255 {
+ if i.BitLen() > maxBitLen {
  ok = false
  return
  }
@@ -130,7 +146,7 @@ func NewIntWithDecimal(n int64, dec int) Int {
  i.Mul(big.NewInt(n), exp)
 
  // Check overflow
- if i.BitLen() > 255 {
+ if i.BitLen() > maxBitLen {
  panic("NewIntWithDecimal() out of bound")
  }
  return Int{i}
@@ -195,7 +211,7 @@ func (i Int) LT(i2 Int) bool {
 func (i Int) Add(i2 Int) (res Int) {
  res = Int{add(i.i, i2.i)}
  // Check overflow
- if res.i.BitLen() > 255 {
+ if res.i.BitLen() > maxBitLen {
  panic("Int overflow")
  }
  return
@@ -210,7 +226,7 @@ func (i Int) AddRaw(i2 int64) Int {
 func (i Int) Sub(i2 Int) (res Int) {
  res = Int{sub(i.i, i2.i)}
  // Check overflow
- if res.i.BitLen() > 255 {
+ if res.i.BitLen() > maxBitLen {
  panic("Int overflow")
  }
  return
@@ -224,12 +240,12 @@ func (i Int) SubRaw(i2 int64) Int {
 // Mul multiples two Ints
 func (i Int) Mul(i2 Int) (res Int) {
  // Check overflow
- if i.i.BitLen()+i2.i.BitLen()-1 > 255 {
+ if i.i.BitLen()+i2.i.BitLen()-1 > maxBitLen {
  panic("Int overflow")
  }
  res = Int{mul(i.i, i2.i)}
  // Check overflow if sign of both are same
- if res.i.BitLen() > 255 {
+ if res.i.BitLen() > maxBitLen {
  panic("Int overflow")
  }
  return

types/int_test.go

@@ -631,3 +631,23 @@ func TestSafeSub(t *testing.T) {
  )
  }
 }
+
+func TestSerializationOverflow(t *testing.T) {
+ bx, _ := new(big.Int).SetString("91888242871839275229946405745257275988696311157297823662689937894645226298583", 10)
+ x := Int{bx}
+ y := new(Int)
+
+ // require amino deserialization to fail due to overflow
+ xStr, err := x.MarshalAmino()
+ require.NoError(t, err)
+
+ err = y.UnmarshalAmino(xStr)
+ require.Error(t, err)
+
+ // require JSON deserialization to fail due to overflow
+ bz, err := x.MarshalJSON()
+ require.NoError(t, err)
+
+ err = y.UnmarshalJSON(bz)
+ require.Error(t, err)
+}