ICS 24 Implementation

types/errors/errors.go

@@ -65,6 +65,12 @@ var (
  // ErrNoSignatures to doc
  ErrNoSignatures = Register(RootCodespace, 16, "no signatures supplied")
 
+ // ErrInvalidId to doc
+ ErrInvalidID = Register(RootCodespace, 17, "invalid identifier")
+
+ // ErrInvalidPath to doc
+ ErrInvalidPath = Register(RootCodespace, 18, "invalid path")
+
  // ErrPanic is only set when we recover from a panic, so we know to
  // redact potentially sensitive system info
  ErrPanic = Register(UndefinedCodespace, 111222, "panic")

x/ibc/23-commitment/keeper/keeper.go

@@ -45,7 +45,10 @@ func (k Keeper) BatchVerifyMembership(ctx sdk.Context, proof exported.ProofI, it
  continue
  }
 
- path := types.ApplyPrefix(k.prefix, pathStr)
+ path, err := types.ApplyPrefix(k.prefix, pathStr)
+ if err != nil {
+ return false
+ }
  ok = proof.VerifyMembership(root, path, value)
  if !ok {
  return false
@@ -69,7 +72,10 @@ func (k Keeper) BatchVerifyNonMembership(ctx sdk.Context, proof exported.ProofI,
  continue
  }
 
- path := types.ApplyPrefix(k.prefix, pathStr)
+ path, err := types.ApplyPrefix(k.prefix, pathStr)
+ if err != nil {
+ return false
+ }
  ok = proof.VerifyNonMembership(root, path)
  if !ok {
  return false

x/ibc/23-commitment/types/merkle.go

@@ -7,6 +7,7 @@ import (
 
  "github.com/cosmos/cosmos-sdk/store/rootmulti"
  "github.com/cosmos/cosmos-sdk/x/ibc/23-commitment/exported"
+ host "github.com/cosmos/cosmos-sdk/x/ibc/24-host"
 )
 
 // ICS 023 Merkle Types Implementation
@@ -103,13 +104,17 @@ func (p Path) String() string {
 //
 // CONTRACT: provided path string MUST be a well formated path. See ICS24 for
 // reference.
-func ApplyPrefix(prefix exported.PrefixI, path string) Path {
+func ApplyPrefix(prefix exported.PrefixI, path string) (Path, error) {
+ err := host.DefaultPathValidator(path)
+ if err != nil {
+ return Path{}, err
+ }
  // Split paths by the separator
  pathSlice := strings.Split(path, "/")
  commitmentPath := NewPath(pathSlice)
 
  commitmentPath.KeyPath = commitmentPath.KeyPath.AppendKey(prefix.Bytes(), merkle.KeyEncodingHex)
- return commitmentPath
+ return commitmentPath, nil
 }
 
 var _ exported.ProofI = Proof{}

x/ibc/24-host/errors.go

@@ -0,0 +1,16 @@
+package host
+
+import (
+ sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
+)
+
+// IBCCodeSpace is the codespace for all errors defined in the ibc module
+const IBCCodeSpace = "ibc"
+
+var (
+ // ErrInvalidID is returned if identifier string is invalid
+ ErrInvalidID = sdkerrors.Register(IBCCodeSpace, 1, "invalid identifier")
+
+ // ErrInvalidPath is returned if path string is invalid
+ ErrInvalidPath = sdkerrors.Register(IBCCodeSpace, 2, "invalid path")
+)

x/ibc/24-host/validate.go

@@ -0,0 +1,74 @@
+package host
+
+import (
+ "regexp"
+ "strings"
+
+ sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
+)
+
+// ICS 024 Identifier and Path Validation Implementation
+//
+// This file defines ValidateFn to validate identifier and path strings
+// The spec for ICS 024 can be located here:
+// https://github.com/cosmos/ics/tree/master/spec/ics-024-host-requirements
+
+// regular expression to check string is lowercase alphabetic characters only
+var isAlphaLower = regexp.MustCompile(`^[a-z]+$`).MatchString
+
+// regular expression to check string is alphanumeric
+var isAlphaNumeric = regexp.MustCompile(`^[a-zA-Z0-9]+$`).MatchString
+
+// ValidateFn function type to validate path and identifier bytestrings
+type ValidateFn func(string) error
+
+// Default validator function for Client, Connection, and Channel
+// identifiers
+// Valid Identifier must be between 10-20 characters and only
+// contain lowercase alphabetic characters
+func DefaultIdentifierValidator(id string) error {
+ // valid id MUST NOT contain "/" separator
+ if strings.Contains(id, "/") {
+ return sdkerrors.Wrap(ErrInvalidID, "identifier cannot contain separator: /")
+ }
+ // valid id must be between 10 and 20 characters
+ if len(id) < 10 || len(id) > 20 {
+ return sdkerrors.Wrapf(ErrInvalidID, "identifier has invalid length: %d, must be between 10-20 characters", len(id))
+ }
+ // valid id must contain only lower alphabetic characters
+ if !isAlphaLower(id) {
+ return sdkerrors.Wrap(ErrInvalidID, "identifier must contain only lowercase alphabetic characters")
+ }
+ return nil
+}
+
+// NewPathValidator takes in a Identifier Validator function and returns
+// a Path Validator function which requires path only has valid identifiers
+// alphanumeric character strings, and "/" separators
+func NewPathValidator(idValidator ValidateFn) ValidateFn {
+ return func(path string) error {
+ pathArr := strings.Split(path, "/")
+ for _, p := range pathArr {
+ // Each path element must either be valid identifier or alphanumeric
+ err := idValidator(p)
+ if err != nil && !isAlphaNumeric(p) {
+ return sdkerrors.Wrapf(ErrInvalidPath, "path contains invalid identifier or non-alphanumeric path element: %s", p)
+ }
+ }
+ return nil
+ }
+}
+
+// Default Path Validator takes in path string and validates
+// with default identifier rules. This is optimized by simply
+// checking that all path elements are alphanumeric
+func DefaultPathValidator(path string) error {
+ pathArr := strings.Split(path, "/")
+ for _, p := range pathArr {
+ // Each path element must either be alphanumeric
+ if !isAlphaNumeric(p) {
+ return sdkerrors.Wrapf(ErrInvalidPath, "invalid path element containing non-alphanumeric characters: %s", p)
+ }
+ }
+ return nil
+}