From 3d64b49358534b61b891ad6a7f752fac63125ef3 Mon Sep 17 00:00:00 2001
From: likhita-809 <likhita@vitwit.com>
Date: Tue, 6 Jul 2021 16:11:21 +0530
Subject: [PATCH 01/10] check store keys length before accessing

---
 x/authz/keeper/keys.go                 | 10 ++++++++++
 x/distribution/migrations/v040/keys.go |  8 ++++++++
 x/distribution/types/keys.go           | 11 +++++++++++
 x/gov/types/keys.go                    |  7 +++++++
 4 files changed, 36 insertions(+)

diff --git a/x/authz/keeper/keys.go b/x/authz/keeper/keys.go
index 3bdd02138efb..c2bbe4a00016 100644
--- a/x/authz/keeper/keys.go
+++ b/x/authz/keeper/keys.go
@@ -1,6 +1,8 @@
 package keeper
 
 import (
+	"fmt"
+
 	"github.com/cosmos/cosmos-sdk/internal/conv"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/address"
@@ -38,10 +40,18 @@ func grantStoreKey(grantee sdk.AccAddress, granter sdk.AccAddress, msgType strin
 func addressesFromGrantStoreKey(key []byte) (granterAddr, granteeAddr sdk.AccAddress) {
 	// key is of format:
 	// 0x01<granterAddressLen (1 Byte)><granterAddress_Bytes><granteeAddressLen (1 Byte)><granteeAddress_Bytes><msgType_Bytes>
+	assertKeyAtLeastLength(key, 2)
 	granterAddrLen := key[1] // remove prefix key
 	granterAddr = sdk.AccAddress(key[2 : 2+granterAddrLen])
+	assertKeyAtLeastLength(key, int(3+granterAddrLen))
 	granteeAddrLen := int(key[2+granterAddrLen])
 	granteeAddr = sdk.AccAddress(key[3+granterAddrLen : 3+granterAddrLen+byte(granteeAddrLen)])
 
 	return granterAddr, granteeAddr
 }
+
+func assertKeyAtLeastLength(bz []byte, length int) {
+	if len(bz) < length {
+		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
+	}
+}
diff --git a/x/distribution/migrations/v040/keys.go b/x/distribution/migrations/v040/keys.go
index c6978a9e31de..ea5235d004e3 100644
--- a/x/distribution/migrations/v040/keys.go
+++ b/x/distribution/migrations/v040/keys.go
@@ -4,6 +4,7 @@ package v040
 
 import (
 	"encoding/binary"
+	"fmt"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	v040auth "github.com/cosmos/cosmos-sdk/x/auth/migrations/v040"
@@ -130,6 +131,7 @@ func GetValidatorSlashEventAddressHeight(key []byte) (valAddr sdk.ValAddress, he
 	}
 	valAddr = sdk.ValAddress(addr)
 	startB := 1 + v040auth.AddrLen
+	assertKeyAtLeastLength(key, startB+9)
 	b := key[startB : startB+8] // the next 8 bytes represent the height
 	height = binary.BigEndian.Uint64(b)
 	return
@@ -194,3 +196,9 @@ func GetValidatorSlashEventKey(v sdk.ValAddress, height, period uint64) []byte {
 	prefix := GetValidatorSlashEventKeyPrefix(v, height)
 	return append(prefix, periodBz...)
 }
+
+func assertKeyAtLeastLength(bz []byte, length int) {
+	if len(bz) < length {
+		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
+	}
+}
diff --git a/x/distribution/types/keys.go b/x/distribution/types/keys.go
index d28ba2d6b7d7..b34b07ee3efd 100644
--- a/x/distribution/types/keys.go
+++ b/x/distribution/types/keys.go
@@ -2,6 +2,7 @@ package types
 
 import (
 	"encoding/binary"
+	fmt "fmt"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/address"
@@ -86,6 +87,7 @@ func GetDelegatorWithdrawInfoAddress(key []byte) (delAddr sdk.AccAddress) {
 func GetDelegatorStartingInfoAddresses(key []byte) (valAddr sdk.ValAddress, delAddr sdk.AccAddress) {
 	// key is in the format:
 	// 0x04<valAddrLen (1 Byte)><valAddr_Bytes><accAddrLen (1 Byte)><accAddr_Bytes>
+	assertKeyAtLeastLength(key, 2)
 	valAddrLen := int(key[1])
 	valAddr = sdk.ValAddress(key[2 : 2+valAddrLen])
 	delAddrLen := int(key[2+valAddrLen])
@@ -101,6 +103,7 @@ func GetDelegatorStartingInfoAddresses(key []byte) (valAddr sdk.ValAddress, delA
 func GetValidatorHistoricalRewardsAddressPeriod(key []byte) (valAddr sdk.ValAddress, period uint64) {
 	// key is in the format:
 	// 0x05<valAddrLen (1 Byte)><valAddr_Bytes><period_Bytes>
+	assertKeyAtLeastLength(key, 2)
 	valAddrLen := int(key[1])
 	valAddr = sdk.ValAddress(key[2 : 2+valAddrLen])
 	b := key[2+valAddrLen:]
@@ -143,9 +146,11 @@ func GetValidatorAccumulatedCommissionAddress(key []byte) (valAddr sdk.ValAddres
 func GetValidatorSlashEventAddressHeight(key []byte) (valAddr sdk.ValAddress, height uint64) {
 	// key is in the format:
 	// 0x08<valAddrLen (1 Byte)><valAddr_Bytes><height>: ValidatorSlashEvent
+	assertKeyAtLeastLength(key, 2)
 	valAddrLen := int(key[1])
 	valAddr = key[2 : 2+valAddrLen]
 	startB := 2 + valAddrLen
+	assertKeyAtLeastLength(key, startB+9)
 	b := key[startB : startB+8] // the next 8 bytes represent the height
 	height = binary.BigEndian.Uint64(b)
 	return
@@ -212,3 +217,9 @@ func GetValidatorSlashEventKey(v sdk.ValAddress, height, period uint64) []byte {
 
 	return append(prefix, periodBz...)
 }
+
+func assertKeyAtLeastLength(bz []byte, length int) {
+	if len(bz) < length {
+		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
+	}
+}
diff --git a/x/gov/types/keys.go b/x/gov/types/keys.go
index fe98bcbf81c4..46e004791e38 100644
--- a/x/gov/types/keys.go
+++ b/x/gov/types/keys.go
@@ -157,7 +157,14 @@ func splitKeyWithTime(key []byte) (proposalID uint64, endTime time.Time) {
 func splitKeyWithAddress(key []byte) (proposalID uint64, addr sdk.AccAddress) {
 	// Both Vote and Deposit store keys are of format:
 	// <prefix (1 Byte)><proposalID (8 bytes)><addrLen (1 Byte)><addr_Bytes>
+	assertKeyAtLeastLength(key, 10)
 	proposalID = GetProposalIDFromBytes(key[1:9])
 	addr = sdk.AccAddress(key[10:])
 	return
 }
+
+func assertKeyAtLeastLength(bz []byte, length int) {
+	if len(bz) < length {
+		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
+	}
+}

From f9f8ccc78979dd6b61a27d9705faa4c0f73da290 Mon Sep 17 00:00:00 2001
From: likhita-809 <likhita@vitwit.com>
Date: Tue, 6 Jul 2021 20:11:06 +0530
Subject: [PATCH 02/10] check store keys length in all modules

---
 x/bank/migrations/v040/keys.go         |  7 +++++++
 x/distribution/migrations/v040/keys.go |  7 +++++++
 x/distribution/types/keys.go           |  7 +++++++
 x/slashing/migrations/v040/keys.go     |  8 ++++++++
 x/staking/migrations/v040/keys.go      |  9 +++++++++
 x/staking/types/keys.go                | 19 +++++++++++++++++++
 6 files changed, 57 insertions(+)

diff --git a/x/bank/migrations/v040/keys.go b/x/bank/migrations/v040/keys.go
index a5674f397438..cae34580b0d9 100644
--- a/x/bank/migrations/v040/keys.go
+++ b/x/bank/migrations/v040/keys.go
@@ -40,6 +40,7 @@ func DenomMetadataKey(denom string) []byte {
 // store. The key must not contain the perfix BalancesPrefix as the prefix store
 // iterator discards the actual prefix.
 func AddressFromBalancesStore(key []byte) sdk.AccAddress {
+	assertKeyAtLeastLength(key, 1+v040auth.AddrLen)
 	addr := key[:v040auth.AddrLen]
 	if len(addr) != v040auth.AddrLen {
 		panic(fmt.Sprintf("unexpected account address key length; got: %d, expected: %d", len(addr), v040auth.AddrLen))
@@ -47,3 +48,9 @@ func AddressFromBalancesStore(key []byte) sdk.AccAddress {
 
 	return sdk.AccAddress(addr)
 }
+
+func assertKeyAtLeastLength(bz []byte, length int) {
+	if len(bz) < length {
+		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
+	}
+}
diff --git a/x/distribution/migrations/v040/keys.go b/x/distribution/migrations/v040/keys.go
index ea5235d004e3..916e84a7262c 100644
--- a/x/distribution/migrations/v040/keys.go
+++ b/x/distribution/migrations/v040/keys.go
@@ -59,6 +59,7 @@ var (
 
 // gets an address from a validator's outstanding rewards key
 func GetValidatorOutstandingRewardsAddress(key []byte) (valAddr sdk.ValAddress) {
+	assertKeyAtLeastLength(key, 2)
 	addr := key[1:]
 	if len(addr) != v040auth.AddrLen {
 		panic("unexpected key length")
@@ -68,6 +69,7 @@ func GetValidatorOutstandingRewardsAddress(key []byte) (valAddr sdk.ValAddress)
 
 // gets an address from a delegator's withdraw info key
 func GetDelegatorWithdrawInfoAddress(key []byte) (delAddr sdk.AccAddress) {
+	assertKeyAtLeastLength(key, 2)
 	addr := key[1:]
 	if len(addr) != v040auth.AddrLen {
 		panic("unexpected key length")
@@ -77,6 +79,7 @@ func GetDelegatorWithdrawInfoAddress(key []byte) (delAddr sdk.AccAddress) {
 
 // gets the addresses from a delegator starting info key
 func GetDelegatorStartingInfoAddresses(key []byte) (valAddr sdk.ValAddress, delAddr sdk.AccAddress) {
+	assertKeyAtLeastLength(key, 2+v040auth.AddrLen)
 	addr := key[1 : 1+v040auth.AddrLen]
 	if len(addr) != v040auth.AddrLen {
 		panic("unexpected key length")
@@ -92,6 +95,7 @@ func GetDelegatorStartingInfoAddresses(key []byte) (valAddr sdk.ValAddress, delA
 
 // gets the address & period from a validator's historical rewards key
 func GetValidatorHistoricalRewardsAddressPeriod(key []byte) (valAddr sdk.ValAddress, period uint64) {
+	assertKeyAtLeastLength(key, 2+v040auth.AddrLen)
 	addr := key[1 : 1+v040auth.AddrLen]
 	if len(addr) != v040auth.AddrLen {
 		panic("unexpected key length")
@@ -107,6 +111,7 @@ func GetValidatorHistoricalRewardsAddressPeriod(key []byte) (valAddr sdk.ValAddr
 
 // gets the address from a validator's current rewards key
 func GetValidatorCurrentRewardsAddress(key []byte) (valAddr sdk.ValAddress) {
+	assertKeyAtLeastLength(key, 2)
 	addr := key[1:]
 	if len(addr) != v040auth.AddrLen {
 		panic("unexpected key length")
@@ -116,6 +121,7 @@ func GetValidatorCurrentRewardsAddress(key []byte) (valAddr sdk.ValAddress) {
 
 // gets the address from a validator's accumulated commission key
 func GetValidatorAccumulatedCommissionAddress(key []byte) (valAddr sdk.ValAddress) {
+	assertKeyAtLeastLength(key, 2)
 	addr := key[1:]
 	if len(addr) != v040auth.AddrLen {
 		panic("unexpected key length")
@@ -125,6 +131,7 @@ func GetValidatorAccumulatedCommissionAddress(key []byte) (valAddr sdk.ValAddres
 
 // gets the height from a validator's slash event key
 func GetValidatorSlashEventAddressHeight(key []byte) (valAddr sdk.ValAddress, height uint64) {
+	assertKeyAtLeastLength(key, 2+v040auth.AddrLen)
 	addr := key[1 : 1+v040auth.AddrLen]
 	if len(addr) != v040auth.AddrLen {
 		panic("unexpected key length")
diff --git a/x/distribution/types/keys.go b/x/distribution/types/keys.go
index b34b07ee3efd..4030ba971b09 100644
--- a/x/distribution/types/keys.go
+++ b/x/distribution/types/keys.go
@@ -61,6 +61,7 @@ func GetValidatorOutstandingRewardsAddress(key []byte) (valAddr sdk.ValAddress)
 	// 0x02<valAddrLen (1 Byte)><valAddr_Bytes>
 
 	// Remove prefix and address length.
+	assertKeyAtLeastLength(key, 3)
 	addr := key[2:]
 	if len(addr) != int(key[1]) {
 		panic("unexpected key length")
@@ -75,6 +76,7 @@ func GetDelegatorWithdrawInfoAddress(key []byte) (delAddr sdk.AccAddress) {
 	// 0x03<accAddrLen (1 Byte)><accAddr_Bytes>
 
 	// Remove prefix and address length.
+	assertKeyAtLeastLength(key, 3)
 	addr := key[2:]
 	if len(addr) != int(key[1]) {
 		panic("unexpected key length")
@@ -90,6 +92,7 @@ func GetDelegatorStartingInfoAddresses(key []byte) (valAddr sdk.ValAddress, delA
 	assertKeyAtLeastLength(key, 2)
 	valAddrLen := int(key[1])
 	valAddr = sdk.ValAddress(key[2 : 2+valAddrLen])
+	assertKeyAtLeastLength(key, 3+valAddrLen)
 	delAddrLen := int(key[2+valAddrLen])
 	delAddr = sdk.AccAddress(key[3+valAddrLen:])
 	if len(delAddr.Bytes()) != delAddrLen {
@@ -106,6 +109,7 @@ func GetValidatorHistoricalRewardsAddressPeriod(key []byte) (valAddr sdk.ValAddr
 	assertKeyAtLeastLength(key, 2)
 	valAddrLen := int(key[1])
 	valAddr = sdk.ValAddress(key[2 : 2+valAddrLen])
+	assertKeyAtLeastLength(key, 3+valAddrLen)
 	b := key[2+valAddrLen:]
 	if len(b) != 8 {
 		panic("unexpected key length")
@@ -120,6 +124,7 @@ func GetValidatorCurrentRewardsAddress(key []byte) (valAddr sdk.ValAddress) {
 	// 0x06<valAddrLen (1 Byte)><valAddr_Bytes>: ValidatorCurrentRewards
 
 	// Remove prefix and address length.
+	assertKeyAtLeastLength(key, 3)
 	addr := key[2:]
 	if len(addr) != int(key[1]) {
 		panic("unexpected key length")
@@ -134,6 +139,7 @@ func GetValidatorAccumulatedCommissionAddress(key []byte) (valAddr sdk.ValAddres
 	// 0x07<valAddrLen (1 Byte)><valAddr_Bytes>: ValidatorCurrentRewards
 
 	// Remove prefix and address length.
+	assertKeyAtLeastLength(key, 3)
 	addr := key[2:]
 	if len(addr) != int(key[1]) {
 		panic("unexpected key length")
@@ -148,6 +154,7 @@ func GetValidatorSlashEventAddressHeight(key []byte) (valAddr sdk.ValAddress, he
 	// 0x08<valAddrLen (1 Byte)><valAddr_Bytes><height>: ValidatorSlashEvent
 	assertKeyAtLeastLength(key, 2)
 	valAddrLen := int(key[1])
+	assertKeyAtLeastLength(key, 3+valAddrLen)
 	valAddr = key[2 : 2+valAddrLen]
 	startB := 2 + valAddrLen
 	assertKeyAtLeastLength(key, startB+9)
diff --git a/x/slashing/migrations/v040/keys.go b/x/slashing/migrations/v040/keys.go
index fe4cb52c5b83..771f2ccd0d6b 100644
--- a/x/slashing/migrations/v040/keys.go
+++ b/x/slashing/migrations/v040/keys.go
@@ -4,6 +4,7 @@ package v040
 
 import (
 	"encoding/binary"
+	"fmt"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	v040auth "github.com/cosmos/cosmos-sdk/x/auth/migrations/v040"
@@ -44,6 +45,7 @@ func ValidatorSigningInfoKey(v sdk.ConsAddress) []byte {
 
 // ValidatorSigningInfoAddress - extract the address from a validator signing info key
 func ValidatorSigningInfoAddress(key []byte) (v sdk.ConsAddress) {
+	assertKeyAtLeastLength(key, 2)
 	addr := key[1:]
 	if len(addr) != v040auth.AddrLen {
 		panic("unexpected key length")
@@ -67,3 +69,9 @@ func ValidatorMissedBlockBitArrayKey(v sdk.ConsAddress, i int64) []byte {
 func AddrPubkeyRelationKey(address []byte) []byte {
 	return append(AddrPubkeyRelationKeyPrefix, address...)
 }
+
+func assertKeyAtLeastLength(bz []byte, length int) {
+	if len(bz) < length {
+		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
+	}
+}
diff --git a/x/staking/migrations/v040/keys.go b/x/staking/migrations/v040/keys.go
index e35ae83a3065..7b6e9896ecec 100644
--- a/x/staking/migrations/v040/keys.go
+++ b/x/staking/migrations/v040/keys.go
@@ -66,6 +66,7 @@ func GetValidatorByConsAddrKey(addr sdk.ConsAddress) []byte {
 
 // Get the validator operator address from LastValidatorPowerKey
 func AddressFromLastValidatorPowerKey(key []byte) []byte {
+	assertKeyAtLeastLength(key, 2)
 	return key[1:] // remove prefix bytes
 }
 
@@ -196,11 +197,13 @@ func GetUBDByValIndexKey(delAddr sdk.AccAddress, valAddr sdk.ValAddress) []byte
 
 // rearranges the ValIndexKey to get the UBDKey
 func GetUBDKeyFromValIndexKey(indexKey []byte) []byte {
+	assertKeyAtLeastLength(indexKey, 2)
 	addrs := indexKey[1:] // remove prefix bytes
 	if len(addrs) != 2*v040auth.AddrLen {
 		panic("unexpected key length")
 	}
 
+	assertKeyAtLeastLength(addrs, v040auth.AddrLen+1)
 	valAddr := addrs[:v040auth.AddrLen]
 	delAddr := addrs[v040auth.AddrLen:]
 
@@ -328,3 +331,9 @@ func GetREDsByDelToValDstIndexKey(delAddr sdk.AccAddress, valDstAddr sdk.ValAddr
 func GetHistoricalInfoKey(height int64) []byte {
 	return append(HistoricalInfoKey, []byte(strconv.FormatInt(height, 10))...)
 }
+
+func assertKeyAtLeastLength(bz []byte, length int) {
+	if len(bz) < length {
+		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
+	}
+}
diff --git a/x/staking/types/keys.go b/x/staking/types/keys.go
index 584dba5684c3..ae0feed34378 100644
--- a/x/staking/types/keys.go
+++ b/x/staking/types/keys.go
@@ -63,11 +63,13 @@ func GetValidatorByConsAddrKey(addr sdk.ConsAddress) []byte {
 
 // AddressFromValidatorsKey creates the validator operator address from ValidatorsKey
 func AddressFromValidatorsKey(key []byte) []byte {
+	assertKeyAtLeastLength(key, 3)
 	return key[2:] // remove prefix bytes and address length
 }
 
 // AddressFromLastValidatorPowerKey creates the validator operator address from LastValidatorPowerKey
 func AddressFromLastValidatorPowerKey(key []byte) []byte {
+	assertKeyAtLeastLength(key, 3)
 	return key[2:] // remove prefix bytes and address length
 }
 
@@ -196,10 +198,13 @@ func GetUBDByValIndexKey(delAddr sdk.AccAddress, valAddr sdk.ValAddress) []byte
 
 // GetUBDKeyFromValIndexKey rearranges the ValIndexKey to get the UBDKey
 func GetUBDKeyFromValIndexKey(indexKey []byte) []byte {
+	assertKeyAtLeastLength(indexKey, 2)
 	addrs := indexKey[1:] // remove prefix bytes
 
 	valAddrLen := addrs[0]
+	assertKeyAtLeastLength(addrs, 2+int(valAddrLen))
 	valAddr := addrs[1 : 1+valAddrLen]
+	assertKeyAtLeastLength(addrs, 3+int(valAddrLen))
 	delAddr := addrs[valAddrLen+2:]
 
 	return GetUBDKey(delAddr, valAddr)
@@ -273,12 +278,16 @@ func GetREDByValDstIndexKey(delAddr sdk.AccAddress, valSrcAddr, valDstAddr sdk.V
 // GetREDKeyFromValSrcIndexKey rearranges the ValSrcIndexKey to get the REDKey
 func GetREDKeyFromValSrcIndexKey(indexKey []byte) []byte {
 	// note that first byte is prefix byte, which we remove
+	assertKeyAtLeastLength(indexKey, 2)
 	addrs := indexKey[1:]
 
 	valSrcAddrLen := addrs[0]
+	assertKeyAtLeastLength(addrs, int(valSrcAddrLen)+2)
 	valSrcAddr := addrs[1 : valSrcAddrLen+1]
 	delAddrLen := addrs[valSrcAddrLen+1]
+	assertKeyAtLeastLength(addrs, int(valSrcAddrLen)+int(delAddrLen)+2)
 	delAddr := addrs[valSrcAddrLen+2 : valSrcAddrLen+2+delAddrLen]
+	assertKeyAtLeastLength(addrs, int(valSrcAddrLen)+int(delAddrLen)+4)
 	valDstAddr := addrs[valSrcAddrLen+delAddrLen+3:]
 
 	return GetREDKey(delAddr, valSrcAddr, valDstAddr)
@@ -287,12 +296,16 @@ func GetREDKeyFromValSrcIndexKey(indexKey []byte) []byte {
 // GetREDKeyFromValDstIndexKey rearranges the ValDstIndexKey to get the REDKey
 func GetREDKeyFromValDstIndexKey(indexKey []byte) []byte {
 	// note that first byte is prefix byte, which we remove
+	assertKeyAtLeastLength(indexKey, 2)
 	addrs := indexKey[1:]
 
 	valDstAddrLen := addrs[0]
+	assertKeyAtLeastLength(addrs, int(valDstAddrLen)+2)
 	valDstAddr := addrs[1 : valDstAddrLen+1]
 	delAddrLen := addrs[valDstAddrLen+1]
+	assertKeyAtLeastLength(addrs, int(valDstAddrLen)+int(delAddrLen)+3)
 	delAddr := addrs[valDstAddrLen+2 : valDstAddrLen+2+delAddrLen]
+	assertKeyAtLeastLength(addrs, int(valDstAddrLen)+int(delAddrLen)+4)
 	valSrcAddr := addrs[valDstAddrLen+delAddrLen+3:]
 
 	return GetREDKey(delAddr, valSrcAddr, valDstAddr)
@@ -333,3 +346,9 @@ func GetREDsByDelToValDstIndexKey(delAddr sdk.AccAddress, valDstAddr sdk.ValAddr
 func GetHistoricalInfoKey(height int64) []byte {
 	return append(HistoricalInfoKey, []byte(strconv.FormatInt(height, 10))...)
 }
+
+func assertKeyAtLeastLength(bz []byte, length int) {
+	if len(bz) < length {
+		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
+	}
+}

From ea2dc7fe06a24249c578d6977ec66468606a7dc8 Mon Sep 17 00:00:00 2001
From: likhita-809 <likhita@vitwit.com>
Date: Wed, 7 Jul 2021 10:05:35 +0530
Subject: [PATCH 03/10] add changelog

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 190615fb26fb..ed058a733366 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -73,6 +73,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Bug Fixes
 
+* [\#9639](https://github.com/cosmos/cosmos-sdk/pull/9639) Check store keys length before accessing them by making sure that `key` is of length `m+1` (for `a := key[n:m]`)
 * (types) [\#9627](https://github.com/cosmos/cosmos-sdk/pull/9627) Fix nil pointer panic on `NewBigIntFromInt`
 * (x/genutil) [\#9574](https://github.com/cosmos/cosmos-sdk/pull/9575) Actually use the `gentx` client tx flags (like `--keyring-dir`)
 * (x/distribution) [\#9599](https://github.com/cosmos/cosmos-sdk/pull/9599) Withdraw rewards event now includes a value attribute even if there are 0 rewards (due to situations like 100% commission).

From c913d0ab7a788ba23b3b9504e2a90c6ea1f1fa15 Mon Sep 17 00:00:00 2001
From: likhita-809 <likhita@vitwit.com>
Date: Wed, 7 Jul 2021 14:49:06 +0530
Subject: [PATCH 04/10] refactoring

---
 types/kv/helpers.go                    |  9 +++++++
 x/authz/keeper/keys.go                 | 13 +++-------
 x/bank/migrations/v040/keys.go         |  9 ++-----
 x/distribution/migrations/v040/keys.go | 24 +++++++------------
 x/distribution/types/keys.go           | 30 ++++++++++-------------
 x/gov/types/keys.go                    |  9 ++-----
 x/slashing/migrations/v040/keys.go     | 10 ++------
 x/staking/migrations/v040/keys.go      | 13 ++++------
 x/staking/types/keys.go                | 33 +++++++++++---------------
 9 files changed, 57 insertions(+), 93 deletions(-)
 create mode 100644 types/kv/helpers.go

diff --git a/types/kv/helpers.go b/types/kv/helpers.go
new file mode 100644
index 000000000000..9158c4d162d3
--- /dev/null
+++ b/types/kv/helpers.go
@@ -0,0 +1,9 @@
+package kv
+
+import "fmt"
+
+func AssertKeyAtLeastLength(bz []byte, length int) {
+	if len(bz) < length {
+		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
+	}
+}
diff --git a/x/authz/keeper/keys.go b/x/authz/keeper/keys.go
index c2bbe4a00016..d5c3b2964400 100644
--- a/x/authz/keeper/keys.go
+++ b/x/authz/keeper/keys.go
@@ -1,11 +1,10 @@
 package keeper
 
 import (
-	"fmt"
-
 	"github.com/cosmos/cosmos-sdk/internal/conv"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/address"
+	"github.com/cosmos/cosmos-sdk/types/kv"
 	"github.com/cosmos/cosmos-sdk/x/authz"
 )
 
@@ -40,18 +39,12 @@ func grantStoreKey(grantee sdk.AccAddress, granter sdk.AccAddress, msgType strin
 func addressesFromGrantStoreKey(key []byte) (granterAddr, granteeAddr sdk.AccAddress) {
 	// key is of format:
 	// 0x01<granterAddressLen (1 Byte)><granterAddress_Bytes><granteeAddressLen (1 Byte)><granteeAddress_Bytes><msgType_Bytes>
-	assertKeyAtLeastLength(key, 2)
+	kv.AssertKeyAtLeastLength(key, 2)
 	granterAddrLen := key[1] // remove prefix key
 	granterAddr = sdk.AccAddress(key[2 : 2+granterAddrLen])
-	assertKeyAtLeastLength(key, int(3+granterAddrLen))
+	kv.AssertKeyAtLeastLength(key, int(3+granterAddrLen))
 	granteeAddrLen := int(key[2+granterAddrLen])
 	granteeAddr = sdk.AccAddress(key[3+granterAddrLen : 3+granterAddrLen+byte(granteeAddrLen)])
 
 	return granterAddr, granteeAddr
 }
-
-func assertKeyAtLeastLength(bz []byte, length int) {
-	if len(bz) < length {
-		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
-	}
-}
diff --git a/x/bank/migrations/v040/keys.go b/x/bank/migrations/v040/keys.go
index cae34580b0d9..582f9dc13b7e 100644
--- a/x/bank/migrations/v040/keys.go
+++ b/x/bank/migrations/v040/keys.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/types/kv"
 	v040auth "github.com/cosmos/cosmos-sdk/x/auth/migrations/v040"
 )
 
@@ -40,7 +41,7 @@ func DenomMetadataKey(denom string) []byte {
 // store. The key must not contain the perfix BalancesPrefix as the prefix store
 // iterator discards the actual prefix.
 func AddressFromBalancesStore(key []byte) sdk.AccAddress {
-	assertKeyAtLeastLength(key, 1+v040auth.AddrLen)
+	kv.AssertKeyAtLeastLength(key, 1+v040auth.AddrLen)
 	addr := key[:v040auth.AddrLen]
 	if len(addr) != v040auth.AddrLen {
 		panic(fmt.Sprintf("unexpected account address key length; got: %d, expected: %d", len(addr), v040auth.AddrLen))
@@ -48,9 +49,3 @@ func AddressFromBalancesStore(key []byte) sdk.AccAddress {
 
 	return sdk.AccAddress(addr)
 }
-
-func assertKeyAtLeastLength(bz []byte, length int) {
-	if len(bz) < length {
-		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
-	}
-}
diff --git a/x/distribution/migrations/v040/keys.go b/x/distribution/migrations/v040/keys.go
index 916e84a7262c..b93b44c0795f 100644
--- a/x/distribution/migrations/v040/keys.go
+++ b/x/distribution/migrations/v040/keys.go
@@ -4,9 +4,9 @@ package v040
 
 import (
 	"encoding/binary"
-	"fmt"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/types/kv"
 	v040auth "github.com/cosmos/cosmos-sdk/x/auth/migrations/v040"
 )
 
@@ -59,7 +59,7 @@ var (
 
 // gets an address from a validator's outstanding rewards key
 func GetValidatorOutstandingRewardsAddress(key []byte) (valAddr sdk.ValAddress) {
-	assertKeyAtLeastLength(key, 2)
+	kv.AssertKeyAtLeastLength(key, 2)
 	addr := key[1:]
 	if len(addr) != v040auth.AddrLen {
 		panic("unexpected key length")
@@ -69,7 +69,7 @@ func GetValidatorOutstandingRewardsAddress(key []byte) (valAddr sdk.ValAddress)
 
 // gets an address from a delegator's withdraw info key
 func GetDelegatorWithdrawInfoAddress(key []byte) (delAddr sdk.AccAddress) {
-	assertKeyAtLeastLength(key, 2)
+	kv.AssertKeyAtLeastLength(key, 2)
 	addr := key[1:]
 	if len(addr) != v040auth.AddrLen {
 		panic("unexpected key length")
@@ -79,7 +79,7 @@ func GetDelegatorWithdrawInfoAddress(key []byte) (delAddr sdk.AccAddress) {
 
 // gets the addresses from a delegator starting info key
 func GetDelegatorStartingInfoAddresses(key []byte) (valAddr sdk.ValAddress, delAddr sdk.AccAddress) {
-	assertKeyAtLeastLength(key, 2+v040auth.AddrLen)
+	kv.AssertKeyAtLeastLength(key, 2+v040auth.AddrLen)
 	addr := key[1 : 1+v040auth.AddrLen]
 	if len(addr) != v040auth.AddrLen {
 		panic("unexpected key length")
@@ -95,7 +95,7 @@ func GetDelegatorStartingInfoAddresses(key []byte) (valAddr sdk.ValAddress, delA
 
 // gets the address & period from a validator's historical rewards key
 func GetValidatorHistoricalRewardsAddressPeriod(key []byte) (valAddr sdk.ValAddress, period uint64) {
-	assertKeyAtLeastLength(key, 2+v040auth.AddrLen)
+	kv.AssertKeyAtLeastLength(key, 2+v040auth.AddrLen)
 	addr := key[1 : 1+v040auth.AddrLen]
 	if len(addr) != v040auth.AddrLen {
 		panic("unexpected key length")
@@ -111,7 +111,7 @@ func GetValidatorHistoricalRewardsAddressPeriod(key []byte) (valAddr sdk.ValAddr
 
 // gets the address from a validator's current rewards key
 func GetValidatorCurrentRewardsAddress(key []byte) (valAddr sdk.ValAddress) {
-	assertKeyAtLeastLength(key, 2)
+	kv.AssertKeyAtLeastLength(key, 2)
 	addr := key[1:]
 	if len(addr) != v040auth.AddrLen {
 		panic("unexpected key length")
@@ -121,7 +121,7 @@ func GetValidatorCurrentRewardsAddress(key []byte) (valAddr sdk.ValAddress) {
 
 // gets the address from a validator's accumulated commission key
 func GetValidatorAccumulatedCommissionAddress(key []byte) (valAddr sdk.ValAddress) {
-	assertKeyAtLeastLength(key, 2)
+	kv.AssertKeyAtLeastLength(key, 2)
 	addr := key[1:]
 	if len(addr) != v040auth.AddrLen {
 		panic("unexpected key length")
@@ -131,14 +131,14 @@ func GetValidatorAccumulatedCommissionAddress(key []byte) (valAddr sdk.ValAddres
 
 // gets the height from a validator's slash event key
 func GetValidatorSlashEventAddressHeight(key []byte) (valAddr sdk.ValAddress, height uint64) {
-	assertKeyAtLeastLength(key, 2+v040auth.AddrLen)
+	kv.AssertKeyAtLeastLength(key, 2+v040auth.AddrLen)
 	addr := key[1 : 1+v040auth.AddrLen]
 	if len(addr) != v040auth.AddrLen {
 		panic("unexpected key length")
 	}
 	valAddr = sdk.ValAddress(addr)
 	startB := 1 + v040auth.AddrLen
-	assertKeyAtLeastLength(key, startB+9)
+	kv.AssertKeyAtLeastLength(key, startB+9)
 	b := key[startB : startB+8] // the next 8 bytes represent the height
 	height = binary.BigEndian.Uint64(b)
 	return
@@ -203,9 +203,3 @@ func GetValidatorSlashEventKey(v sdk.ValAddress, height, period uint64) []byte {
 	prefix := GetValidatorSlashEventKeyPrefix(v, height)
 	return append(prefix, periodBz...)
 }
-
-func assertKeyAtLeastLength(bz []byte, length int) {
-	if len(bz) < length {
-		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
-	}
-}
diff --git a/x/distribution/types/keys.go b/x/distribution/types/keys.go
index 4030ba971b09..985d36b0575a 100644
--- a/x/distribution/types/keys.go
+++ b/x/distribution/types/keys.go
@@ -2,10 +2,10 @@ package types
 
 import (
 	"encoding/binary"
-	fmt "fmt"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/address"
+	"github.com/cosmos/cosmos-sdk/types/kv"
 )
 
 const (
@@ -61,7 +61,7 @@ func GetValidatorOutstandingRewardsAddress(key []byte) (valAddr sdk.ValAddress)
 	// 0x02<valAddrLen (1 Byte)><valAddr_Bytes>
 
 	// Remove prefix and address length.
-	assertKeyAtLeastLength(key, 3)
+	kv.AssertKeyAtLeastLength(key, 3)
 	addr := key[2:]
 	if len(addr) != int(key[1]) {
 		panic("unexpected key length")
@@ -76,7 +76,7 @@ func GetDelegatorWithdrawInfoAddress(key []byte) (delAddr sdk.AccAddress) {
 	// 0x03<accAddrLen (1 Byte)><accAddr_Bytes>
 
 	// Remove prefix and address length.
-	assertKeyAtLeastLength(key, 3)
+	kv.AssertKeyAtLeastLength(key, 3)
 	addr := key[2:]
 	if len(addr) != int(key[1]) {
 		panic("unexpected key length")
@@ -89,10 +89,10 @@ func GetDelegatorWithdrawInfoAddress(key []byte) (delAddr sdk.AccAddress) {
 func GetDelegatorStartingInfoAddresses(key []byte) (valAddr sdk.ValAddress, delAddr sdk.AccAddress) {
 	// key is in the format:
 	// 0x04<valAddrLen (1 Byte)><valAddr_Bytes><accAddrLen (1 Byte)><accAddr_Bytes>
-	assertKeyAtLeastLength(key, 2)
+	kv.AssertKeyAtLeastLength(key, 2)
 	valAddrLen := int(key[1])
 	valAddr = sdk.ValAddress(key[2 : 2+valAddrLen])
-	assertKeyAtLeastLength(key, 3+valAddrLen)
+	kv.AssertKeyAtLeastLength(key, 3+valAddrLen)
 	delAddrLen := int(key[2+valAddrLen])
 	delAddr = sdk.AccAddress(key[3+valAddrLen:])
 	if len(delAddr.Bytes()) != delAddrLen {
@@ -106,10 +106,10 @@ func GetDelegatorStartingInfoAddresses(key []byte) (valAddr sdk.ValAddress, delA
 func GetValidatorHistoricalRewardsAddressPeriod(key []byte) (valAddr sdk.ValAddress, period uint64) {
 	// key is in the format:
 	// 0x05<valAddrLen (1 Byte)><valAddr_Bytes><period_Bytes>
-	assertKeyAtLeastLength(key, 2)
+	kv.AssertKeyAtLeastLength(key, 2)
 	valAddrLen := int(key[1])
 	valAddr = sdk.ValAddress(key[2 : 2+valAddrLen])
-	assertKeyAtLeastLength(key, 3+valAddrLen)
+	kv.AssertKeyAtLeastLength(key, 3+valAddrLen)
 	b := key[2+valAddrLen:]
 	if len(b) != 8 {
 		panic("unexpected key length")
@@ -124,7 +124,7 @@ func GetValidatorCurrentRewardsAddress(key []byte) (valAddr sdk.ValAddress) {
 	// 0x06<valAddrLen (1 Byte)><valAddr_Bytes>: ValidatorCurrentRewards
 
 	// Remove prefix and address length.
-	assertKeyAtLeastLength(key, 3)
+	kv.AssertKeyAtLeastLength(key, 3)
 	addr := key[2:]
 	if len(addr) != int(key[1]) {
 		panic("unexpected key length")
@@ -139,7 +139,7 @@ func GetValidatorAccumulatedCommissionAddress(key []byte) (valAddr sdk.ValAddres
 	// 0x07<valAddrLen (1 Byte)><valAddr_Bytes>: ValidatorCurrentRewards
 
 	// Remove prefix and address length.
-	assertKeyAtLeastLength(key, 3)
+	kv.AssertKeyAtLeastLength(key, 3)
 	addr := key[2:]
 	if len(addr) != int(key[1]) {
 		panic("unexpected key length")
@@ -152,12 +152,12 @@ func GetValidatorAccumulatedCommissionAddress(key []byte) (valAddr sdk.ValAddres
 func GetValidatorSlashEventAddressHeight(key []byte) (valAddr sdk.ValAddress, height uint64) {
 	// key is in the format:
 	// 0x08<valAddrLen (1 Byte)><valAddr_Bytes><height>: ValidatorSlashEvent
-	assertKeyAtLeastLength(key, 2)
+	kv.AssertKeyAtLeastLength(key, 2)
 	valAddrLen := int(key[1])
-	assertKeyAtLeastLength(key, 3+valAddrLen)
+	kv.AssertKeyAtLeastLength(key, 3+valAddrLen)
 	valAddr = key[2 : 2+valAddrLen]
 	startB := 2 + valAddrLen
-	assertKeyAtLeastLength(key, startB+9)
+	kv.AssertKeyAtLeastLength(key, startB+9)
 	b := key[startB : startB+8] // the next 8 bytes represent the height
 	height = binary.BigEndian.Uint64(b)
 	return
@@ -224,9 +224,3 @@ func GetValidatorSlashEventKey(v sdk.ValAddress, height, period uint64) []byte {
 
 	return append(prefix, periodBz...)
 }
-
-func assertKeyAtLeastLength(bz []byte, length int) {
-	if len(bz) < length {
-		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
-	}
-}
diff --git a/x/gov/types/keys.go b/x/gov/types/keys.go
index 46e004791e38..93f180033670 100644
--- a/x/gov/types/keys.go
+++ b/x/gov/types/keys.go
@@ -7,6 +7,7 @@ import (
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/address"
+	"github.com/cosmos/cosmos-sdk/types/kv"
 )
 
 const (
@@ -157,14 +158,8 @@ func splitKeyWithTime(key []byte) (proposalID uint64, endTime time.Time) {
 func splitKeyWithAddress(key []byte) (proposalID uint64, addr sdk.AccAddress) {
 	// Both Vote and Deposit store keys are of format:
 	// <prefix (1 Byte)><proposalID (8 bytes)><addrLen (1 Byte)><addr_Bytes>
-	assertKeyAtLeastLength(key, 10)
+	kv.AssertKeyAtLeastLength(key, 10)
 	proposalID = GetProposalIDFromBytes(key[1:9])
 	addr = sdk.AccAddress(key[10:])
 	return
 }
-
-func assertKeyAtLeastLength(bz []byte, length int) {
-	if len(bz) < length {
-		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
-	}
-}
diff --git a/x/slashing/migrations/v040/keys.go b/x/slashing/migrations/v040/keys.go
index 771f2ccd0d6b..c18785961bd8 100644
--- a/x/slashing/migrations/v040/keys.go
+++ b/x/slashing/migrations/v040/keys.go
@@ -4,9 +4,9 @@ package v040
 
 import (
 	"encoding/binary"
-	"fmt"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/types/kv"
 	v040auth "github.com/cosmos/cosmos-sdk/x/auth/migrations/v040"
 )
 
@@ -45,7 +45,7 @@ func ValidatorSigningInfoKey(v sdk.ConsAddress) []byte {
 
 // ValidatorSigningInfoAddress - extract the address from a validator signing info key
 func ValidatorSigningInfoAddress(key []byte) (v sdk.ConsAddress) {
-	assertKeyAtLeastLength(key, 2)
+	kv.AssertKeyAtLeastLength(key, 2)
 	addr := key[1:]
 	if len(addr) != v040auth.AddrLen {
 		panic("unexpected key length")
@@ -69,9 +69,3 @@ func ValidatorMissedBlockBitArrayKey(v sdk.ConsAddress, i int64) []byte {
 func AddrPubkeyRelationKey(address []byte) []byte {
 	return append(AddrPubkeyRelationKeyPrefix, address...)
 }
-
-func assertKeyAtLeastLength(bz []byte, length int) {
-	if len(bz) < length {
-		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
-	}
-}
diff --git a/x/staking/migrations/v040/keys.go b/x/staking/migrations/v040/keys.go
index 7b6e9896ecec..80c573df1230 100644
--- a/x/staking/migrations/v040/keys.go
+++ b/x/staking/migrations/v040/keys.go
@@ -10,6 +10,7 @@ import (
 	"time"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/types/kv"
 	v040auth "github.com/cosmos/cosmos-sdk/x/auth/migrations/v040"
 	"github.com/cosmos/cosmos-sdk/x/staking/types"
 )
@@ -66,7 +67,7 @@ func GetValidatorByConsAddrKey(addr sdk.ConsAddress) []byte {
 
 // Get the validator operator address from LastValidatorPowerKey
 func AddressFromLastValidatorPowerKey(key []byte) []byte {
-	assertKeyAtLeastLength(key, 2)
+	kv.AssertKeyAtLeastLength(key, 2)
 	return key[1:] // remove prefix bytes
 }
 
@@ -197,13 +198,13 @@ func GetUBDByValIndexKey(delAddr sdk.AccAddress, valAddr sdk.ValAddress) []byte
 
 // rearranges the ValIndexKey to get the UBDKey
 func GetUBDKeyFromValIndexKey(indexKey []byte) []byte {
-	assertKeyAtLeastLength(indexKey, 2)
+	kv.AssertKeyAtLeastLength(indexKey, 2)
 	addrs := indexKey[1:] // remove prefix bytes
 	if len(addrs) != 2*v040auth.AddrLen {
 		panic("unexpected key length")
 	}
 
-	assertKeyAtLeastLength(addrs, v040auth.AddrLen+1)
+	kv.AssertKeyAtLeastLength(addrs, v040auth.AddrLen+1)
 	valAddr := addrs[:v040auth.AddrLen]
 	delAddr := addrs[v040auth.AddrLen:]
 
@@ -331,9 +332,3 @@ func GetREDsByDelToValDstIndexKey(delAddr sdk.AccAddress, valDstAddr sdk.ValAddr
 func GetHistoricalInfoKey(height int64) []byte {
 	return append(HistoricalInfoKey, []byte(strconv.FormatInt(height, 10))...)
 }
-
-func assertKeyAtLeastLength(bz []byte, length int) {
-	if len(bz) < length {
-		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
-	}
-}
diff --git a/x/staking/types/keys.go b/x/staking/types/keys.go
index ae0feed34378..74d73bf19c7e 100644
--- a/x/staking/types/keys.go
+++ b/x/staking/types/keys.go
@@ -9,6 +9,7 @@ import (
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/address"
+	"github.com/cosmos/cosmos-sdk/types/kv"
 )
 
 const (
@@ -63,13 +64,13 @@ func GetValidatorByConsAddrKey(addr sdk.ConsAddress) []byte {
 
 // AddressFromValidatorsKey creates the validator operator address from ValidatorsKey
 func AddressFromValidatorsKey(key []byte) []byte {
-	assertKeyAtLeastLength(key, 3)
+	kv.AssertKeyAtLeastLength(key, 3)
 	return key[2:] // remove prefix bytes and address length
 }
 
 // AddressFromLastValidatorPowerKey creates the validator operator address from LastValidatorPowerKey
 func AddressFromLastValidatorPowerKey(key []byte) []byte {
-	assertKeyAtLeastLength(key, 3)
+	kv.AssertKeyAtLeastLength(key, 3)
 	return key[2:] // remove prefix bytes and address length
 }
 
@@ -198,13 +199,13 @@ func GetUBDByValIndexKey(delAddr sdk.AccAddress, valAddr sdk.ValAddress) []byte
 
 // GetUBDKeyFromValIndexKey rearranges the ValIndexKey to get the UBDKey
 func GetUBDKeyFromValIndexKey(indexKey []byte) []byte {
-	assertKeyAtLeastLength(indexKey, 2)
+	kv.AssertKeyAtLeastLength(indexKey, 2)
 	addrs := indexKey[1:] // remove prefix bytes
 
 	valAddrLen := addrs[0]
-	assertKeyAtLeastLength(addrs, 2+int(valAddrLen))
+	kv.AssertKeyAtLeastLength(addrs, 2+int(valAddrLen))
 	valAddr := addrs[1 : 1+valAddrLen]
-	assertKeyAtLeastLength(addrs, 3+int(valAddrLen))
+	kv.AssertKeyAtLeastLength(addrs, 3+int(valAddrLen))
 	delAddr := addrs[valAddrLen+2:]
 
 	return GetUBDKey(delAddr, valAddr)
@@ -278,16 +279,16 @@ func GetREDByValDstIndexKey(delAddr sdk.AccAddress, valSrcAddr, valDstAddr sdk.V
 // GetREDKeyFromValSrcIndexKey rearranges the ValSrcIndexKey to get the REDKey
 func GetREDKeyFromValSrcIndexKey(indexKey []byte) []byte {
 	// note that first byte is prefix byte, which we remove
-	assertKeyAtLeastLength(indexKey, 2)
+	kv.AssertKeyAtLeastLength(indexKey, 2)
 	addrs := indexKey[1:]
 
 	valSrcAddrLen := addrs[0]
-	assertKeyAtLeastLength(addrs, int(valSrcAddrLen)+2)
+	kv.AssertKeyAtLeastLength(addrs, int(valSrcAddrLen)+2)
 	valSrcAddr := addrs[1 : valSrcAddrLen+1]
 	delAddrLen := addrs[valSrcAddrLen+1]
-	assertKeyAtLeastLength(addrs, int(valSrcAddrLen)+int(delAddrLen)+2)
+	kv.AssertKeyAtLeastLength(addrs, int(valSrcAddrLen)+int(delAddrLen)+2)
 	delAddr := addrs[valSrcAddrLen+2 : valSrcAddrLen+2+delAddrLen]
-	assertKeyAtLeastLength(addrs, int(valSrcAddrLen)+int(delAddrLen)+4)
+	kv.AssertKeyAtLeastLength(addrs, int(valSrcAddrLen)+int(delAddrLen)+4)
 	valDstAddr := addrs[valSrcAddrLen+delAddrLen+3:]
 
 	return GetREDKey(delAddr, valSrcAddr, valDstAddr)
@@ -296,16 +297,16 @@ func GetREDKeyFromValSrcIndexKey(indexKey []byte) []byte {
 // GetREDKeyFromValDstIndexKey rearranges the ValDstIndexKey to get the REDKey
 func GetREDKeyFromValDstIndexKey(indexKey []byte) []byte {
 	// note that first byte is prefix byte, which we remove
-	assertKeyAtLeastLength(indexKey, 2)
+	kv.AssertKeyAtLeastLength(indexKey, 2)
 	addrs := indexKey[1:]
 
 	valDstAddrLen := addrs[0]
-	assertKeyAtLeastLength(addrs, int(valDstAddrLen)+2)
+	kv.AssertKeyAtLeastLength(addrs, int(valDstAddrLen)+2)
 	valDstAddr := addrs[1 : valDstAddrLen+1]
 	delAddrLen := addrs[valDstAddrLen+1]
-	assertKeyAtLeastLength(addrs, int(valDstAddrLen)+int(delAddrLen)+3)
+	kv.AssertKeyAtLeastLength(addrs, int(valDstAddrLen)+int(delAddrLen)+3)
 	delAddr := addrs[valDstAddrLen+2 : valDstAddrLen+2+delAddrLen]
-	assertKeyAtLeastLength(addrs, int(valDstAddrLen)+int(delAddrLen)+4)
+	kv.AssertKeyAtLeastLength(addrs, int(valDstAddrLen)+int(delAddrLen)+4)
 	valSrcAddr := addrs[valDstAddrLen+delAddrLen+3:]
 
 	return GetREDKey(delAddr, valSrcAddr, valDstAddr)
@@ -346,9 +347,3 @@ func GetREDsByDelToValDstIndexKey(delAddr sdk.AccAddress, valDstAddr sdk.ValAddr
 func GetHistoricalInfoKey(height int64) []byte {
 	return append(HistoricalInfoKey, []byte(strconv.FormatInt(height, 10))...)
 }
-
-func assertKeyAtLeastLength(bz []byte, length int) {
-	if len(bz) < length {
-		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
-	}
-}

From d5271f0a50ef1b93fbbb4681cdb07988b931a1e9 Mon Sep 17 00:00:00 2001
From: likhita-809 <likhita@vitwit.com>
Date: Wed, 7 Jul 2021 19:42:33 +0530
Subject: [PATCH 05/10] address review comments

---
 CHANGELOG.md                           |  4 +-
 types/kv/helpers.go                    |  7 +++
 x/authz/keeper/keys.go                 |  3 +-
 x/bank/migrations/v040/keys.go         | 10 ++--
 x/distribution/migrations/v040/keys.go | 63 +++++++++++++++-----------
 x/distribution/types/keys.go           | 47 +++++++++++--------
 x/gov/migrations/v040/keys.go          | 24 ++++++----
 x/gov/types/keys.go                    | 16 ++++---
 x/slashing/migrations/v040/keys.go     |  7 +--
 x/slashing/types/keys.go               |  2 +
 x/staking/migrations/v040/keys.go      | 28 +++++++-----
 11 files changed, 123 insertions(+), 88 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 50ba1dec765d..d8714bd05522 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -70,11 +70,11 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Improvements
 
-* (cli) [\#9593](https://github.com/cosmos/cosmos-sdk/pull/9593) Check if chain-id is blank before verifying signatures in multisign and error.
+* (cli) [\#9593](https://github.com/cosmos/cosmos-sdk/pull/9593) Check if chain-id is blank before verifying signatures in multisign xxand error.
 
 ### Bug Fixes
 
-* [\#9639](https://github.com/cosmos/cosmos-sdk/pull/9639) Check store keys length before accessing them by making sure that `key` is of length `m+1` (for `a := key[n:m]`)
+* [\#9639](https://github.com/cosmos/cosmos-sdk/pull/9639) Check store keys length before accessing them by making sure that `key` is of length `m+1` (for `key[n:m]`)
 * (types) [\#9627](https://github.com/cosmos/cosmos-sdk/pull/9627) Fix nil pointer panic on `NewBigIntFromInt`
 * (x/genutil) [\#9574](https://github.com/cosmos/cosmos-sdk/pull/9575) Actually use the `gentx` client tx flags (like `--keyring-dir`)
 * (x/distribution) [\#9599](https://github.com/cosmos/cosmos-sdk/pull/9599) Withdraw rewards event now includes a value attribute even if there are 0 rewards (due to situations like 100% commission).
diff --git a/types/kv/helpers.go b/types/kv/helpers.go
index 9158c4d162d3..3f8a9e233e3e 100644
--- a/types/kv/helpers.go
+++ b/types/kv/helpers.go
@@ -7,3 +7,10 @@ func AssertKeyAtLeastLength(bz []byte, length int) {
 		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
 	}
 }
+
+func AssertKeyLength(addr []byte, length int) {
+	if len(addr) != length {
+		// panic(fmt.Sprintf("unexpected key length\nexpected key of length %d", length))
+		panic(fmt.Sprintf("unexpected key length; got: %d, expected: %d", len(addr), length))
+	}
+}
diff --git a/x/authz/keeper/keys.go b/x/authz/keeper/keys.go
index d5c3b2964400..76ac447e37aa 100644
--- a/x/authz/keeper/keys.go
+++ b/x/authz/keeper/keys.go
@@ -41,9 +41,10 @@ func addressesFromGrantStoreKey(key []byte) (granterAddr, granteeAddr sdk.AccAdd
 	// 0x01<granterAddressLen (1 Byte)><granterAddress_Bytes><granteeAddressLen (1 Byte)><granteeAddress_Bytes><msgType_Bytes>
 	kv.AssertKeyAtLeastLength(key, 2)
 	granterAddrLen := key[1] // remove prefix key
-	granterAddr = sdk.AccAddress(key[2 : 2+granterAddrLen])
 	kv.AssertKeyAtLeastLength(key, int(3+granterAddrLen))
+	granterAddr = sdk.AccAddress(key[2 : 2+granterAddrLen])
 	granteeAddrLen := int(key[2+granterAddrLen])
+	kv.AssertKeyAtLeastLength(key, 4+int(granterAddrLen+byte(granteeAddrLen)))
 	granteeAddr = sdk.AccAddress(key[3+granterAddrLen : 3+granterAddrLen+byte(granteeAddrLen)])
 
 	return granterAddr, granteeAddr
diff --git a/x/bank/migrations/v040/keys.go b/x/bank/migrations/v040/keys.go
index 582f9dc13b7e..e8b510e95905 100644
--- a/x/bank/migrations/v040/keys.go
+++ b/x/bank/migrations/v040/keys.go
@@ -3,8 +3,6 @@
 package v040
 
 import (
-	"fmt"
-
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/kv"
 	v040auth "github.com/cosmos/cosmos-sdk/x/auth/migrations/v040"
@@ -43,9 +41,9 @@ func DenomMetadataKey(denom string) []byte {
 func AddressFromBalancesStore(key []byte) sdk.AccAddress {
 	kv.AssertKeyAtLeastLength(key, 1+v040auth.AddrLen)
 	addr := key[:v040auth.AddrLen]
-	if len(addr) != v040auth.AddrLen {
-		panic(fmt.Sprintf("unexpected account address key length; got: %d, expected: %d", len(addr), v040auth.AddrLen))
-	}
-
+	kv.AssertKeyLength(addr, v040auth.AddrLen)
+	// if len(addr) != v040auth.AddrLen {
+	// 	panic(fmt.Sprintf("unexpected account address key length; got: %d, expected: %d", len(addr), v040auth.AddrLen))
+	// }
 	return sdk.AccAddress(addr)
 }
diff --git a/x/distribution/migrations/v040/keys.go b/x/distribution/migrations/v040/keys.go
index b93b44c0795f..3f33220b3f12 100644
--- a/x/distribution/migrations/v040/keys.go
+++ b/x/distribution/migrations/v040/keys.go
@@ -61,9 +61,10 @@ var (
 func GetValidatorOutstandingRewardsAddress(key []byte) (valAddr sdk.ValAddress) {
 	kv.AssertKeyAtLeastLength(key, 2)
 	addr := key[1:]
-	if len(addr) != v040auth.AddrLen {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(addr, v040auth.AddrLen)
+	// if len(addr) != v040auth.AddrLen {
+	// 	panic("unexpected key length")
+	// }
 	return sdk.ValAddress(addr)
 }
 
@@ -71,9 +72,10 @@ func GetValidatorOutstandingRewardsAddress(key []byte) (valAddr sdk.ValAddress)
 func GetDelegatorWithdrawInfoAddress(key []byte) (delAddr sdk.AccAddress) {
 	kv.AssertKeyAtLeastLength(key, 2)
 	addr := key[1:]
-	if len(addr) != v040auth.AddrLen {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(addr, v040auth.AddrLen)
+	// if len(addr) != v040auth.AddrLen {
+	// 	panic("unexpected key length")
+	// }
 	return sdk.AccAddress(addr)
 }
 
@@ -81,14 +83,16 @@ func GetDelegatorWithdrawInfoAddress(key []byte) (delAddr sdk.AccAddress) {
 func GetDelegatorStartingInfoAddresses(key []byte) (valAddr sdk.ValAddress, delAddr sdk.AccAddress) {
 	kv.AssertKeyAtLeastLength(key, 2+v040auth.AddrLen)
 	addr := key[1 : 1+v040auth.AddrLen]
-	if len(addr) != v040auth.AddrLen {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(addr, v040auth.AddrLen)
+	// if len(addr) != v040auth.AddrLen {
+	// 	panic("unexpected key length")
+	// }
 	valAddr = sdk.ValAddress(addr)
 	addr = key[1+v040auth.AddrLen:]
-	if len(addr) != v040auth.AddrLen {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(addr, v040auth.AddrLen)
+	// if len(addr) != v040auth.AddrLen {
+	// 	panic("unexpected key length")
+	// }
 	delAddr = sdk.AccAddress(addr)
 	return
 }
@@ -97,14 +101,16 @@ func GetDelegatorStartingInfoAddresses(key []byte) (valAddr sdk.ValAddress, delA
 func GetValidatorHistoricalRewardsAddressPeriod(key []byte) (valAddr sdk.ValAddress, period uint64) {
 	kv.AssertKeyAtLeastLength(key, 2+v040auth.AddrLen)
 	addr := key[1 : 1+v040auth.AddrLen]
-	if len(addr) != v040auth.AddrLen {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(addr, v040auth.AddrLen)
+	// if len(addr) != v040auth.AddrLen {
+	// 	panic("unexpected key length")
+	// }
 	valAddr = sdk.ValAddress(addr)
 	b := key[1+v040auth.AddrLen:]
-	if len(b) != 8 {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(addr, 8)
+	// if len(b) != 8 {
+	// 	panic("unexpected key length")
+	// }
 	period = binary.LittleEndian.Uint64(b)
 	return
 }
@@ -113,9 +119,10 @@ func GetValidatorHistoricalRewardsAddressPeriod(key []byte) (valAddr sdk.ValAddr
 func GetValidatorCurrentRewardsAddress(key []byte) (valAddr sdk.ValAddress) {
 	kv.AssertKeyAtLeastLength(key, 2)
 	addr := key[1:]
-	if len(addr) != v040auth.AddrLen {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(addr, v040auth.AddrLen)
+	// if len(addr) != v040auth.AddrLen {
+	// 	panic("unexpected key length")
+	// }
 	return sdk.ValAddress(addr)
 }
 
@@ -123,9 +130,10 @@ func GetValidatorCurrentRewardsAddress(key []byte) (valAddr sdk.ValAddress) {
 func GetValidatorAccumulatedCommissionAddress(key []byte) (valAddr sdk.ValAddress) {
 	kv.AssertKeyAtLeastLength(key, 2)
 	addr := key[1:]
-	if len(addr) != v040auth.AddrLen {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(addr, v040auth.AddrLen)
+	// if len(addr) != v040auth.AddrLen {
+	// 	panic("unexpected key length")
+	// }
 	return sdk.ValAddress(addr)
 }
 
@@ -133,9 +141,10 @@ func GetValidatorAccumulatedCommissionAddress(key []byte) (valAddr sdk.ValAddres
 func GetValidatorSlashEventAddressHeight(key []byte) (valAddr sdk.ValAddress, height uint64) {
 	kv.AssertKeyAtLeastLength(key, 2+v040auth.AddrLen)
 	addr := key[1 : 1+v040auth.AddrLen]
-	if len(addr) != v040auth.AddrLen {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(addr, v040auth.AddrLen)
+	// if len(addr) != v040auth.AddrLen {
+	// 	panic("unexpected key length")
+	// }
 	valAddr = sdk.ValAddress(addr)
 	startB := 1 + v040auth.AddrLen
 	kv.AssertKeyAtLeastLength(key, startB+9)
diff --git a/x/distribution/types/keys.go b/x/distribution/types/keys.go
index 985d36b0575a..03c7d1668706 100644
--- a/x/distribution/types/keys.go
+++ b/x/distribution/types/keys.go
@@ -63,9 +63,10 @@ func GetValidatorOutstandingRewardsAddress(key []byte) (valAddr sdk.ValAddress)
 	// Remove prefix and address length.
 	kv.AssertKeyAtLeastLength(key, 3)
 	addr := key[2:]
-	if len(addr) != int(key[1]) {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(addr, int(key[1]))
+	// if len(addr) != int(key[1]) {
+	// 	panic("unexpected key length")
+	// }
 
 	return sdk.ValAddress(addr)
 }
@@ -78,9 +79,10 @@ func GetDelegatorWithdrawInfoAddress(key []byte) (delAddr sdk.AccAddress) {
 	// Remove prefix and address length.
 	kv.AssertKeyAtLeastLength(key, 3)
 	addr := key[2:]
-	if len(addr) != int(key[1]) {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(addr, int(key[1]))
+	// if len(addr) != int(key[1]) {
+	// 	panic("unexpected key length")
+	// }
 
 	return sdk.AccAddress(addr)
 }
@@ -91,13 +93,15 @@ func GetDelegatorStartingInfoAddresses(key []byte) (valAddr sdk.ValAddress, delA
 	// 0x04<valAddrLen (1 Byte)><valAddr_Bytes><accAddrLen (1 Byte)><accAddr_Bytes>
 	kv.AssertKeyAtLeastLength(key, 2)
 	valAddrLen := int(key[1])
-	valAddr = sdk.ValAddress(key[2 : 2+valAddrLen])
 	kv.AssertKeyAtLeastLength(key, 3+valAddrLen)
+	valAddr = sdk.ValAddress(key[2 : 2+valAddrLen])
 	delAddrLen := int(key[2+valAddrLen])
+	kv.AssertKeyAtLeastLength(key, 4+valAddrLen)
 	delAddr = sdk.AccAddress(key[3+valAddrLen:])
-	if len(delAddr.Bytes()) != delAddrLen {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(delAddr.Bytes(), delAddrLen)
+	// if len(delAddr.Bytes()) != delAddrLen {
+	// 	panic("unexpected key length")
+	// }
 
 	return
 }
@@ -108,12 +112,13 @@ func GetValidatorHistoricalRewardsAddressPeriod(key []byte) (valAddr sdk.ValAddr
 	// 0x05<valAddrLen (1 Byte)><valAddr_Bytes><period_Bytes>
 	kv.AssertKeyAtLeastLength(key, 2)
 	valAddrLen := int(key[1])
-	valAddr = sdk.ValAddress(key[2 : 2+valAddrLen])
 	kv.AssertKeyAtLeastLength(key, 3+valAddrLen)
+	valAddr = sdk.ValAddress(key[2 : 2+valAddrLen])
 	b := key[2+valAddrLen:]
-	if len(b) != 8 {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(b, 8)
+	// if len(b) != 8 {
+	// 	panic("unexpected key length")
+	// }
 	period = binary.LittleEndian.Uint64(b)
 	return
 }
@@ -126,9 +131,10 @@ func GetValidatorCurrentRewardsAddress(key []byte) (valAddr sdk.ValAddress) {
 	// Remove prefix and address length.
 	kv.AssertKeyAtLeastLength(key, 3)
 	addr := key[2:]
-	if len(addr) != int(key[1]) {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(addr, int(key[1]))
+	// if len(addr) != int(key[1]) {
+	// 	panic("unexpected key length")
+	// }
 
 	return sdk.ValAddress(addr)
 }
@@ -141,9 +147,10 @@ func GetValidatorAccumulatedCommissionAddress(key []byte) (valAddr sdk.ValAddres
 	// Remove prefix and address length.
 	kv.AssertKeyAtLeastLength(key, 3)
 	addr := key[2:]
-	if len(addr) != int(key[1]) {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(addr, int(key[1]))
+	// if len(addr) != int(key[1]) {
+	// 	panic("unexpected key length")
+	// }
 
 	return sdk.ValAddress(addr)
 }
diff --git a/x/gov/migrations/v040/keys.go b/x/gov/migrations/v040/keys.go
index 8fe2e4413d8f..9c311fde3ea5 100644
--- a/x/gov/migrations/v040/keys.go
+++ b/x/gov/migrations/v040/keys.go
@@ -4,10 +4,10 @@ package v040
 
 import (
 	"encoding/binary"
-	"fmt"
 	"time"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/types/kv"
 	v040auth "github.com/cosmos/cosmos-sdk/x/auth/migrations/v040"
 )
 
@@ -113,9 +113,10 @@ func VoteKey(proposalID uint64, voterAddr sdk.AccAddress) []byte {
 
 // SplitProposalKey split the proposal key and returns the proposal id
 func SplitProposalKey(key []byte) (proposalID uint64) {
-	if len(key[1:]) != 8 {
-		panic(fmt.Sprintf("unexpected key length (%d ≠ 8)", len(key[1:])))
-	}
+	kv.AssertKeyLength(key[1:], 8)
+	// if len(key[1:]) != 8 {
+	// 	panic(fmt.Sprintf("unexpected key length (%d ≠ 8)", len(key[1:])))
+	// }
 
 	return GetProposalIDFromBytes(key[1:])
 }
@@ -143,9 +144,10 @@ func SplitKeyVote(key []byte) (proposalID uint64, voterAddr sdk.AccAddress) {
 // private functions
 
 func splitKeyWithTime(key []byte) (proposalID uint64, endTime time.Time) {
-	if len(key[1:]) != 8+lenTime {
-		panic(fmt.Sprintf("unexpected key length (%d ≠ %d)", len(key[1:]), lenTime+8))
-	}
+	kv.AssertKeyLength(key[1:], 8+lenTime)
+	// if len(key[1:]) != 8+lenTime {
+	// 	panic(fmt.Sprintf("unexpected key length (%d ≠ %d)", len(key[1:]), lenTime+8))
+	// }
 
 	endTime, err := sdk.ParseTimeBytes(key[1 : 1+lenTime])
 	if err != nil {
@@ -157,10 +159,12 @@ func splitKeyWithTime(key []byte) (proposalID uint64, endTime time.Time) {
 }
 
 func splitKeyWithAddress(key []byte) (proposalID uint64, addr sdk.AccAddress) {
-	if len(key[1:]) != 8+v040auth.AddrLen {
-		panic(fmt.Sprintf("unexpected key length (%d ≠ %d)", len(key), 8+v040auth.AddrLen))
-	}
+	kv.AssertKeyLength(key[1:], 8+v040auth.AddrLen)
+	// if len(key[1:]) != 8+v040auth.AddrLen {
+	// 	panic(fmt.Sprintf("unexpected key length (%d ≠ %d)", len(key), 8+v040auth.AddrLen))
+	// }
 
+	kv.AssertKeyAtLeastLength(key, 10)
 	proposalID = GetProposalIDFromBytes(key[1:9])
 	addr = sdk.AccAddress(key[9:])
 	return
diff --git a/x/gov/types/keys.go b/x/gov/types/keys.go
index 93f180033670..6145f29104b5 100644
--- a/x/gov/types/keys.go
+++ b/x/gov/types/keys.go
@@ -2,7 +2,6 @@ package types
 
 import (
 	"encoding/binary"
-	"fmt"
 	"time"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
@@ -112,9 +111,10 @@ func VoteKey(proposalID uint64, voterAddr sdk.AccAddress) []byte {
 
 // SplitProposalKey split the proposal key and returns the proposal id
 func SplitProposalKey(key []byte) (proposalID uint64) {
-	if len(key[1:]) != 8 {
-		panic(fmt.Sprintf("unexpected key length (%d ≠ 8)", len(key[1:])))
-	}
+	kv.AssertKeyLength(key[1:], 8)
+	// if len(key[1:]) != 8 {
+	// 	panic(fmt.Sprintf("unexpected key length (%d ≠ 8)", len(key[1:])))
+	// }
 
 	return GetProposalIDFromBytes(key[1:])
 }
@@ -142,9 +142,10 @@ func SplitKeyVote(key []byte) (proposalID uint64, voterAddr sdk.AccAddress) {
 // private functions
 
 func splitKeyWithTime(key []byte) (proposalID uint64, endTime time.Time) {
-	if len(key[1:]) != 8+lenTime {
-		panic(fmt.Sprintf("unexpected key length (%d ≠ %d)", len(key[1:]), lenTime+8))
-	}
+	kv.AssertKeyLength(key[1:], 8+lenTime)
+	// if len(key[1:]) != 8+lenTime {
+	// 	panic(fmt.Sprintf("unexpected key length (%d ≠ %d)", len(key[1:]), lenTime+8))
+	// }
 
 	endTime, err := sdk.ParseTimeBytes(key[1 : 1+lenTime])
 	if err != nil {
@@ -160,6 +161,7 @@ func splitKeyWithAddress(key []byte) (proposalID uint64, addr sdk.AccAddress) {
 	// <prefix (1 Byte)><proposalID (8 bytes)><addrLen (1 Byte)><addr_Bytes>
 	kv.AssertKeyAtLeastLength(key, 10)
 	proposalID = GetProposalIDFromBytes(key[1:9])
+	kv.AssertKeyAtLeastLength(key, 11)
 	addr = sdk.AccAddress(key[10:])
 	return
 }
diff --git a/x/slashing/migrations/v040/keys.go b/x/slashing/migrations/v040/keys.go
index c18785961bd8..0ee7e3e9cfee 100644
--- a/x/slashing/migrations/v040/keys.go
+++ b/x/slashing/migrations/v040/keys.go
@@ -47,9 +47,10 @@ func ValidatorSigningInfoKey(v sdk.ConsAddress) []byte {
 func ValidatorSigningInfoAddress(key []byte) (v sdk.ConsAddress) {
 	kv.AssertKeyAtLeastLength(key, 2)
 	addr := key[1:]
-	if len(addr) != v040auth.AddrLen {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(addr, v040auth.AddrLen)
+	// if len(addr) != v040auth.AddrLen {
+	// 	panic("unexpected key length")
+	// }
 	return sdk.ConsAddress(addr)
 }
 
diff --git a/x/slashing/types/keys.go b/x/slashing/types/keys.go
index f0049760f0a0..09c978c9a4d5 100644
--- a/x/slashing/types/keys.go
+++ b/x/slashing/types/keys.go
@@ -5,6 +5,7 @@ import (
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/address"
+	"github.com/cosmos/cosmos-sdk/types/kv"
 )
 
 const (
@@ -43,6 +44,7 @@ func ValidatorSigningInfoKey(v sdk.ConsAddress) []byte {
 // ValidatorSigningInfoAddress - extract the address from a validator signing info key
 func ValidatorSigningInfoAddress(key []byte) (v sdk.ConsAddress) {
 	// Remove prefix and address length.
+	kv.AssertKeyAtLeastLength(key, 3)
 	addr := key[2:]
 
 	return sdk.ConsAddress(addr)
diff --git a/x/staking/migrations/v040/keys.go b/x/staking/migrations/v040/keys.go
index 80c573df1230..e846468fa0fe 100644
--- a/x/staking/migrations/v040/keys.go
+++ b/x/staking/migrations/v040/keys.go
@@ -114,9 +114,10 @@ func GetLastValidatorPowerKey(operator sdk.ValAddress) []byte {
 // parse the validators operator address from power rank key
 func ParseValidatorPowerRankKey(key []byte) (operAddr []byte) {
 	powerBytesLen := 8
-	if len(key) != 1+powerBytesLen+v040auth.AddrLen {
-		panic("Invalid validator power rank key length")
-	}
+	kv.AssertKeyLength(key, 1+powerBytesLen+v040auth.AddrLen)
+	// if len(key) != 1+powerBytesLen+v040auth.AddrLen {
+	// 	panic("Invalid validator power rank key length")
+	// }
 
 	operAddr = sdk.CopyBytes(key[powerBytesLen+1:])
 
@@ -200,9 +201,10 @@ func GetUBDByValIndexKey(delAddr sdk.AccAddress, valAddr sdk.ValAddress) []byte
 func GetUBDKeyFromValIndexKey(indexKey []byte) []byte {
 	kv.AssertKeyAtLeastLength(indexKey, 2)
 	addrs := indexKey[1:] // remove prefix bytes
-	if len(addrs) != 2*v040auth.AddrLen {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(addrs, 2*v040auth.AddrLen)
+	// if len(addrs) != 2*v040auth.AddrLen {
+	// 	panic("unexpected key length")
+	// }
 
 	kv.AssertKeyAtLeastLength(addrs, v040auth.AddrLen+1)
 	valAddr := addrs[:v040auth.AddrLen]
@@ -272,9 +274,10 @@ func GetREDByValDstIndexKey(delAddr sdk.AccAddress, valSrcAddr, valDstAddr sdk.V
 // GetREDKeyFromValSrcIndexKey rearranges the ValSrcIndexKey to get the REDKey
 func GetREDKeyFromValSrcIndexKey(indexKey []byte) []byte {
 	// note that first byte is prefix byte
-	if len(indexKey) != 3*v040auth.AddrLen+1 {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(indexKey, 3*v040auth.AddrLen+1)
+	// if len(indexKey) != 3*v040auth.AddrLen+1 {
+	// 	panic("unexpected key length")
+	// }
 
 	valSrcAddr := indexKey[1 : v040auth.AddrLen+1]
 	delAddr := indexKey[v040auth.AddrLen+1 : 2*v040auth.AddrLen+1]
@@ -286,9 +289,10 @@ func GetREDKeyFromValSrcIndexKey(indexKey []byte) []byte {
 // GetREDKeyFromValDstIndexKey rearranges the ValDstIndexKey to get the REDKey
 func GetREDKeyFromValDstIndexKey(indexKey []byte) []byte {
 	// note that first byte is prefix byte
-	if len(indexKey) != 3*v040auth.AddrLen+1 {
-		panic("unexpected key length")
-	}
+	kv.AssertKeyLength(indexKey, 3*v040auth.AddrLen+1)
+	// if len(indexKey) != 3*v040auth.AddrLen+1 {
+	// 	panic("unexpected key length")
+	// }
 
 	valDstAddr := indexKey[1 : v040auth.AddrLen+1]
 	delAddr := indexKey[v040auth.AddrLen+1 : 2*v040auth.AddrLen+1]

From 2a4e1d6376a2799d9733706cdc1d3bf39869b86d Mon Sep 17 00:00:00 2001
From: likhita-809 <likhita@vitwit.com>
Date: Wed, 7 Jul 2021 20:13:44 +0530
Subject: [PATCH 06/10] remove commented lines

---
 x/bank/migrations/v040/keys.go         |  3 ---
 x/distribution/migrations/v040/keys.go | 27 --------------------------
 x/distribution/types/keys.go           | 18 -----------------
 x/gov/migrations/v040/keys.go          |  9 ---------
 x/gov/types/keys.go                    |  6 ------
 x/slashing/migrations/v040/keys.go     |  3 ---
 x/staking/migrations/v040/keys.go      | 12 ------------
 7 files changed, 78 deletions(-)

diff --git a/x/bank/migrations/v040/keys.go b/x/bank/migrations/v040/keys.go
index e8b510e95905..38bb49a0032d 100644
--- a/x/bank/migrations/v040/keys.go
+++ b/x/bank/migrations/v040/keys.go
@@ -42,8 +42,5 @@ func AddressFromBalancesStore(key []byte) sdk.AccAddress {
 	kv.AssertKeyAtLeastLength(key, 1+v040auth.AddrLen)
 	addr := key[:v040auth.AddrLen]
 	kv.AssertKeyLength(addr, v040auth.AddrLen)
-	// if len(addr) != v040auth.AddrLen {
-	// 	panic(fmt.Sprintf("unexpected account address key length; got: %d, expected: %d", len(addr), v040auth.AddrLen))
-	// }
 	return sdk.AccAddress(addr)
 }
diff --git a/x/distribution/migrations/v040/keys.go b/x/distribution/migrations/v040/keys.go
index 3f33220b3f12..db8b1548a343 100644
--- a/x/distribution/migrations/v040/keys.go
+++ b/x/distribution/migrations/v040/keys.go
@@ -62,9 +62,6 @@ func GetValidatorOutstandingRewardsAddress(key []byte) (valAddr sdk.ValAddress)
 	kv.AssertKeyAtLeastLength(key, 2)
 	addr := key[1:]
 	kv.AssertKeyLength(addr, v040auth.AddrLen)
-	// if len(addr) != v040auth.AddrLen {
-	// 	panic("unexpected key length")
-	// }
 	return sdk.ValAddress(addr)
 }
 
@@ -73,9 +70,6 @@ func GetDelegatorWithdrawInfoAddress(key []byte) (delAddr sdk.AccAddress) {
 	kv.AssertKeyAtLeastLength(key, 2)
 	addr := key[1:]
 	kv.AssertKeyLength(addr, v040auth.AddrLen)
-	// if len(addr) != v040auth.AddrLen {
-	// 	panic("unexpected key length")
-	// }
 	return sdk.AccAddress(addr)
 }
 
@@ -84,15 +78,9 @@ func GetDelegatorStartingInfoAddresses(key []byte) (valAddr sdk.ValAddress, delA
 	kv.AssertKeyAtLeastLength(key, 2+v040auth.AddrLen)
 	addr := key[1 : 1+v040auth.AddrLen]
 	kv.AssertKeyLength(addr, v040auth.AddrLen)
-	// if len(addr) != v040auth.AddrLen {
-	// 	panic("unexpected key length")
-	// }
 	valAddr = sdk.ValAddress(addr)
 	addr = key[1+v040auth.AddrLen:]
 	kv.AssertKeyLength(addr, v040auth.AddrLen)
-	// if len(addr) != v040auth.AddrLen {
-	// 	panic("unexpected key length")
-	// }
 	delAddr = sdk.AccAddress(addr)
 	return
 }
@@ -102,15 +90,9 @@ func GetValidatorHistoricalRewardsAddressPeriod(key []byte) (valAddr sdk.ValAddr
 	kv.AssertKeyAtLeastLength(key, 2+v040auth.AddrLen)
 	addr := key[1 : 1+v040auth.AddrLen]
 	kv.AssertKeyLength(addr, v040auth.AddrLen)
-	// if len(addr) != v040auth.AddrLen {
-	// 	panic("unexpected key length")
-	// }
 	valAddr = sdk.ValAddress(addr)
 	b := key[1+v040auth.AddrLen:]
 	kv.AssertKeyLength(addr, 8)
-	// if len(b) != 8 {
-	// 	panic("unexpected key length")
-	// }
 	period = binary.LittleEndian.Uint64(b)
 	return
 }
@@ -120,9 +102,6 @@ func GetValidatorCurrentRewardsAddress(key []byte) (valAddr sdk.ValAddress) {
 	kv.AssertKeyAtLeastLength(key, 2)
 	addr := key[1:]
 	kv.AssertKeyLength(addr, v040auth.AddrLen)
-	// if len(addr) != v040auth.AddrLen {
-	// 	panic("unexpected key length")
-	// }
 	return sdk.ValAddress(addr)
 }
 
@@ -131,9 +110,6 @@ func GetValidatorAccumulatedCommissionAddress(key []byte) (valAddr sdk.ValAddres
 	kv.AssertKeyAtLeastLength(key, 2)
 	addr := key[1:]
 	kv.AssertKeyLength(addr, v040auth.AddrLen)
-	// if len(addr) != v040auth.AddrLen {
-	// 	panic("unexpected key length")
-	// }
 	return sdk.ValAddress(addr)
 }
 
@@ -142,9 +118,6 @@ func GetValidatorSlashEventAddressHeight(key []byte) (valAddr sdk.ValAddress, he
 	kv.AssertKeyAtLeastLength(key, 2+v040auth.AddrLen)
 	addr := key[1 : 1+v040auth.AddrLen]
 	kv.AssertKeyLength(addr, v040auth.AddrLen)
-	// if len(addr) != v040auth.AddrLen {
-	// 	panic("unexpected key length")
-	// }
 	valAddr = sdk.ValAddress(addr)
 	startB := 1 + v040auth.AddrLen
 	kv.AssertKeyAtLeastLength(key, startB+9)
diff --git a/x/distribution/types/keys.go b/x/distribution/types/keys.go
index 03c7d1668706..e0458459d080 100644
--- a/x/distribution/types/keys.go
+++ b/x/distribution/types/keys.go
@@ -64,9 +64,6 @@ func GetValidatorOutstandingRewardsAddress(key []byte) (valAddr sdk.ValAddress)
 	kv.AssertKeyAtLeastLength(key, 3)
 	addr := key[2:]
 	kv.AssertKeyLength(addr, int(key[1]))
-	// if len(addr) != int(key[1]) {
-	// 	panic("unexpected key length")
-	// }
 
 	return sdk.ValAddress(addr)
 }
@@ -80,9 +77,6 @@ func GetDelegatorWithdrawInfoAddress(key []byte) (delAddr sdk.AccAddress) {
 	kv.AssertKeyAtLeastLength(key, 3)
 	addr := key[2:]
 	kv.AssertKeyLength(addr, int(key[1]))
-	// if len(addr) != int(key[1]) {
-	// 	panic("unexpected key length")
-	// }
 
 	return sdk.AccAddress(addr)
 }
@@ -99,9 +93,6 @@ func GetDelegatorStartingInfoAddresses(key []byte) (valAddr sdk.ValAddress, delA
 	kv.AssertKeyAtLeastLength(key, 4+valAddrLen)
 	delAddr = sdk.AccAddress(key[3+valAddrLen:])
 	kv.AssertKeyLength(delAddr.Bytes(), delAddrLen)
-	// if len(delAddr.Bytes()) != delAddrLen {
-	// 	panic("unexpected key length")
-	// }
 
 	return
 }
@@ -116,9 +107,6 @@ func GetValidatorHistoricalRewardsAddressPeriod(key []byte) (valAddr sdk.ValAddr
 	valAddr = sdk.ValAddress(key[2 : 2+valAddrLen])
 	b := key[2+valAddrLen:]
 	kv.AssertKeyLength(b, 8)
-	// if len(b) != 8 {
-	// 	panic("unexpected key length")
-	// }
 	period = binary.LittleEndian.Uint64(b)
 	return
 }
@@ -132,9 +120,6 @@ func GetValidatorCurrentRewardsAddress(key []byte) (valAddr sdk.ValAddress) {
 	kv.AssertKeyAtLeastLength(key, 3)
 	addr := key[2:]
 	kv.AssertKeyLength(addr, int(key[1]))
-	// if len(addr) != int(key[1]) {
-	// 	panic("unexpected key length")
-	// }
 
 	return sdk.ValAddress(addr)
 }
@@ -148,9 +133,6 @@ func GetValidatorAccumulatedCommissionAddress(key []byte) (valAddr sdk.ValAddres
 	kv.AssertKeyAtLeastLength(key, 3)
 	addr := key[2:]
 	kv.AssertKeyLength(addr, int(key[1]))
-	// if len(addr) != int(key[1]) {
-	// 	panic("unexpected key length")
-	// }
 
 	return sdk.ValAddress(addr)
 }
diff --git a/x/gov/migrations/v040/keys.go b/x/gov/migrations/v040/keys.go
index 9c311fde3ea5..5b8a6536cafa 100644
--- a/x/gov/migrations/v040/keys.go
+++ b/x/gov/migrations/v040/keys.go
@@ -114,9 +114,6 @@ func VoteKey(proposalID uint64, voterAddr sdk.AccAddress) []byte {
 // SplitProposalKey split the proposal key and returns the proposal id
 func SplitProposalKey(key []byte) (proposalID uint64) {
 	kv.AssertKeyLength(key[1:], 8)
-	// if len(key[1:]) != 8 {
-	// 	panic(fmt.Sprintf("unexpected key length (%d ≠ 8)", len(key[1:])))
-	// }
 
 	return GetProposalIDFromBytes(key[1:])
 }
@@ -145,9 +142,6 @@ func SplitKeyVote(key []byte) (proposalID uint64, voterAddr sdk.AccAddress) {
 
 func splitKeyWithTime(key []byte) (proposalID uint64, endTime time.Time) {
 	kv.AssertKeyLength(key[1:], 8+lenTime)
-	// if len(key[1:]) != 8+lenTime {
-	// 	panic(fmt.Sprintf("unexpected key length (%d ≠ %d)", len(key[1:]), lenTime+8))
-	// }
 
 	endTime, err := sdk.ParseTimeBytes(key[1 : 1+lenTime])
 	if err != nil {
@@ -160,9 +154,6 @@ func splitKeyWithTime(key []byte) (proposalID uint64, endTime time.Time) {
 
 func splitKeyWithAddress(key []byte) (proposalID uint64, addr sdk.AccAddress) {
 	kv.AssertKeyLength(key[1:], 8+v040auth.AddrLen)
-	// if len(key[1:]) != 8+v040auth.AddrLen {
-	// 	panic(fmt.Sprintf("unexpected key length (%d ≠ %d)", len(key), 8+v040auth.AddrLen))
-	// }
 
 	kv.AssertKeyAtLeastLength(key, 10)
 	proposalID = GetProposalIDFromBytes(key[1:9])
diff --git a/x/gov/types/keys.go b/x/gov/types/keys.go
index 6145f29104b5..7f58d8fdfbac 100644
--- a/x/gov/types/keys.go
+++ b/x/gov/types/keys.go
@@ -112,9 +112,6 @@ func VoteKey(proposalID uint64, voterAddr sdk.AccAddress) []byte {
 // SplitProposalKey split the proposal key and returns the proposal id
 func SplitProposalKey(key []byte) (proposalID uint64) {
 	kv.AssertKeyLength(key[1:], 8)
-	// if len(key[1:]) != 8 {
-	// 	panic(fmt.Sprintf("unexpected key length (%d ≠ 8)", len(key[1:])))
-	// }
 
 	return GetProposalIDFromBytes(key[1:])
 }
@@ -143,9 +140,6 @@ func SplitKeyVote(key []byte) (proposalID uint64, voterAddr sdk.AccAddress) {
 
 func splitKeyWithTime(key []byte) (proposalID uint64, endTime time.Time) {
 	kv.AssertKeyLength(key[1:], 8+lenTime)
-	// if len(key[1:]) != 8+lenTime {
-	// 	panic(fmt.Sprintf("unexpected key length (%d ≠ %d)", len(key[1:]), lenTime+8))
-	// }
 
 	endTime, err := sdk.ParseTimeBytes(key[1 : 1+lenTime])
 	if err != nil {
diff --git a/x/slashing/migrations/v040/keys.go b/x/slashing/migrations/v040/keys.go
index 0ee7e3e9cfee..367ead65e5cc 100644
--- a/x/slashing/migrations/v040/keys.go
+++ b/x/slashing/migrations/v040/keys.go
@@ -48,9 +48,6 @@ func ValidatorSigningInfoAddress(key []byte) (v sdk.ConsAddress) {
 	kv.AssertKeyAtLeastLength(key, 2)
 	addr := key[1:]
 	kv.AssertKeyLength(addr, v040auth.AddrLen)
-	// if len(addr) != v040auth.AddrLen {
-	// 	panic("unexpected key length")
-	// }
 	return sdk.ConsAddress(addr)
 }
 
diff --git a/x/staking/migrations/v040/keys.go b/x/staking/migrations/v040/keys.go
index e846468fa0fe..27e2f9eae02b 100644
--- a/x/staking/migrations/v040/keys.go
+++ b/x/staking/migrations/v040/keys.go
@@ -115,9 +115,6 @@ func GetLastValidatorPowerKey(operator sdk.ValAddress) []byte {
 func ParseValidatorPowerRankKey(key []byte) (operAddr []byte) {
 	powerBytesLen := 8
 	kv.AssertKeyLength(key, 1+powerBytesLen+v040auth.AddrLen)
-	// if len(key) != 1+powerBytesLen+v040auth.AddrLen {
-	// 	panic("Invalid validator power rank key length")
-	// }
 
 	operAddr = sdk.CopyBytes(key[powerBytesLen+1:])
 
@@ -202,9 +199,6 @@ func GetUBDKeyFromValIndexKey(indexKey []byte) []byte {
 	kv.AssertKeyAtLeastLength(indexKey, 2)
 	addrs := indexKey[1:] // remove prefix bytes
 	kv.AssertKeyLength(addrs, 2*v040auth.AddrLen)
-	// if len(addrs) != 2*v040auth.AddrLen {
-	// 	panic("unexpected key length")
-	// }
 
 	kv.AssertKeyAtLeastLength(addrs, v040auth.AddrLen+1)
 	valAddr := addrs[:v040auth.AddrLen]
@@ -275,9 +269,6 @@ func GetREDByValDstIndexKey(delAddr sdk.AccAddress, valSrcAddr, valDstAddr sdk.V
 func GetREDKeyFromValSrcIndexKey(indexKey []byte) []byte {
 	// note that first byte is prefix byte
 	kv.AssertKeyLength(indexKey, 3*v040auth.AddrLen+1)
-	// if len(indexKey) != 3*v040auth.AddrLen+1 {
-	// 	panic("unexpected key length")
-	// }
 
 	valSrcAddr := indexKey[1 : v040auth.AddrLen+1]
 	delAddr := indexKey[v040auth.AddrLen+1 : 2*v040auth.AddrLen+1]
@@ -290,9 +281,6 @@ func GetREDKeyFromValSrcIndexKey(indexKey []byte) []byte {
 func GetREDKeyFromValDstIndexKey(indexKey []byte) []byte {
 	// note that first byte is prefix byte
 	kv.AssertKeyLength(indexKey, 3*v040auth.AddrLen+1)
-	// if len(indexKey) != 3*v040auth.AddrLen+1 {
-	// 	panic("unexpected key length")
-	// }
 
 	valDstAddr := indexKey[1 : v040auth.AddrLen+1]
 	delAddr := indexKey[v040auth.AddrLen+1 : 2*v040auth.AddrLen+1]

From 95978821776c21fa66e4797b1d8c0d59448c2482 Mon Sep 17 00:00:00 2001
From: likhita-809 <likhita@vitwit.com>
Date: Wed, 7 Jul 2021 20:23:37 +0530
Subject: [PATCH 07/10] small fixes

---
 CHANGELOG.md        | 2 +-
 types/kv/helpers.go | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d8714bd05522..837de46c86a2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -70,7 +70,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Improvements
 
-* (cli) [\#9593](https://github.com/cosmos/cosmos-sdk/pull/9593) Check if chain-id is blank before verifying signatures in multisign xxand error.
+* (cli) [\#9593](https://github.com/cosmos/cosmos-sdk/pull/9593) Check if chain-id is blank before verifying signatures in multisign and error.
 
 ### Bug Fixes
 
diff --git a/types/kv/helpers.go b/types/kv/helpers.go
index 3f8a9e233e3e..2eabb093b54a 100644
--- a/types/kv/helpers.go
+++ b/types/kv/helpers.go
@@ -10,7 +10,6 @@ func AssertKeyAtLeastLength(bz []byte, length int) {
 
 func AssertKeyLength(addr []byte, length int) {
 	if len(addr) != length {
-		// panic(fmt.Sprintf("unexpected key length\nexpected key of length %d", length))
 		panic(fmt.Sprintf("unexpected key length; got: %d, expected: %d", len(addr), length))
 	}
 }

From cd8e279fc2728a4517177a7542633ccbc331a1fb Mon Sep 17 00:00:00 2001
From: likhita-809 <likhita@vitwit.com>
Date: Thu, 8 Jul 2021 15:29:53 +0530
Subject: [PATCH 08/10] address review comments

---
 types/kv/helpers.go | 6 +++---
 x/bank/types/key.go | 3 +++
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/types/kv/helpers.go b/types/kv/helpers.go
index 2eabb093b54a..582c9f31077a 100644
--- a/types/kv/helpers.go
+++ b/types/kv/helpers.go
@@ -8,8 +8,8 @@ func AssertKeyAtLeastLength(bz []byte, length int) {
 	}
 }
 
-func AssertKeyLength(addr []byte, length int) {
-	if len(addr) != length {
-		panic(fmt.Sprintf("unexpected key length; got: %d, expected: %d", len(addr), length))
+func AssertKeyLength(bz []byte, length int) {
+	if len(bz) != length {
+		panic(fmt.Sprintf("unexpected key length; got: %d, expected: %d", len(bz), length))
 	}
 }
diff --git a/x/bank/types/key.go b/x/bank/types/key.go
index 5d7f52baa531..13d0471ff75e 100644
--- a/x/bank/types/key.go
+++ b/x/bank/types/key.go
@@ -3,6 +3,7 @@ package types
 import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/address"
+	"github.com/cosmos/cosmos-sdk/types/kv"
 )
 
 const (
@@ -43,8 +44,10 @@ func AddressFromBalancesStore(key []byte) (sdk.AccAddress, error) {
 	if len(key) == 0 {
 		return nil, ErrInvalidKey
 	}
+	kv.AssertKeyAtLeastLength(key, 1)
 	addrLen := key[0]
 	bound := int(addrLen)
+	kv.AssertKeyAtLeastLength(key, bound+2)
 	if len(key)-1 < bound {
 		return nil, ErrInvalidKey
 	}

From c2b75898ba02085ff0d3b72f689aa416f6000942 Mon Sep 17 00:00:00 2001
From: likhita-809 <likhita@vitwit.com>
Date: Thu, 8 Jul 2021 16:10:50 +0530
Subject: [PATCH 09/10] fix failing tests

---
 x/bank/types/key.go | 1 -
 1 file changed, 1 deletion(-)

diff --git a/x/bank/types/key.go b/x/bank/types/key.go
index 13d0471ff75e..e91a38970e8b 100644
--- a/x/bank/types/key.go
+++ b/x/bank/types/key.go
@@ -47,7 +47,6 @@ func AddressFromBalancesStore(key []byte) (sdk.AccAddress, error) {
 	kv.AssertKeyAtLeastLength(key, 1)
 	addrLen := key[0]
 	bound := int(addrLen)
-	kv.AssertKeyAtLeastLength(key, bound+2)
 	if len(key)-1 < bound {
 		return nil, ErrInvalidKey
 	}

From 8b6e32e7c6c706227ab2a1529767623a88208bcc Mon Sep 17 00:00:00 2001
From: likhita-809 <likhita@vitwit.com>
Date: Thu, 8 Jul 2021 16:36:41 +0530
Subject: [PATCH 10/10] add godocs

---
 types/kv/helpers.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/types/kv/helpers.go b/types/kv/helpers.go
index 582c9f31077a..5bccea122eb5 100644
--- a/types/kv/helpers.go
+++ b/types/kv/helpers.go
@@ -2,12 +2,14 @@ package kv
 
 import "fmt"
 
+// AssertKeyAtLeastLength panics when store key length is less than the given length.
 func AssertKeyAtLeastLength(bz []byte, length int) {
 	if len(bz) < length {
 		panic(fmt.Sprintf("expected key of length at least %d, got %d", length, len(bz)))
 	}
 }
 
+// AssertKeyLength panics when store key length is not equal to the given length.
 func AssertKeyLength(bz []byte, length int) {
 	if len(bz) != length {
 		panic(fmt.Sprintf("unexpected key length; got: %d, expected: %d", len(bz), length))