Merge pull request #3532 from onflow/fxamacker/check-cbor-tag-range-f…

…or-cadence-internal-value-encoding

Check if CBOR tag number is reserved by atree before using it to encode Cadence values

go.mod

@@ -13,7 +13,7 @@ require (
 	github.com/kr/pretty v0.3.1
 	github.com/leanovate/gopter v0.2.9
 	github.com/logrusorgru/aurora/v4 v4.0.0
-	github.com/onflow/atree v0.8.0-rc.5
+	github.com/onflow/atree v0.8.0-rc.6
 	github.com/rivo/uniseg v0.4.4
 	github.com/schollz/progressbar/v3 v3.13.1
 	github.com/stretchr/testify v1.9.0

go.sum

@@ -75,8 +75,8 @@ github.com/mitchellh/colorstring v0.0.0-20190213212951-d06e56a500db h1:62I3jR2Em
 github.com/mitchellh/colorstring v0.0.0-20190213212951-d06e56a500db/go.mod h1:l0dey0ia/Uv7NcFFVbCLtqEBQbrT4OCwCSKTEv6enCw=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWbfPhv4DMiApHyliiK5xCTNVSPiaAs=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
-github.com/onflow/atree v0.8.0-rc.5 h1:1sU+c6UfDzq/EjM8nTw4EI8GvEMarcxkWkJKy6piFSY=
-github.com/onflow/atree v0.8.0-rc.5/go.mod h1:yccR+LR7xc1Jdic0mrjocbHvUD7lnVvg8/Ct1AA5zBo=
+github.com/onflow/atree v0.8.0-rc.6 h1:GWgaylK24b5ta2Hq+TvyOF7X5tZLiLzMMn7lEt59fsA=
+github.com/onflow/atree v0.8.0-rc.6/go.mod h1:yccR+LR7xc1Jdic0mrjocbHvUD7lnVvg8/Ct1AA5zBo=
 github.com/onflow/crypto v0.25.0 h1:BeWbLsh3ZD13Ej+Uky6kg1PL1ZIVBDVX+2MVBNwqddg=
 github.com/onflow/crypto v0.25.0/go.mod h1:C8FbaX0x8y+FxWjbkHy0Q4EASCDR9bSPWZqlpCLYyVI=
 github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=

runtime/cmd/decode-state-values/main.go

@@ -115,23 +115,13 @@ func decodeSlab(id atree.SlabID, data []byte) (atree.Slab, error) {
 }
 
 func slabIDToStorageKey(id atree.SlabID) storageKey {
-	const (
-		addressSize = len(atree.Address{})
-		indexSize   = len(atree.SlabIndex{})
-		slabIDSize  = addressSize + indexSize
-		indexPos    = addressSize
-	)
-
-	var b [slabIDSize]byte
-	_, err := id.ToRawBytes(b[:])
-	if err != nil {
-		panic(err)
-	}
+	address := id.Address()
+	index := id.Index()
 
 	return storageKey{
-		string(b[:addressSize]),
+		string(address[:]),
 		"",
-		"$" + string(b[indexPos:]),
+		"$" + string(index[:]),
 	}
 }
 

runtime/interpreter/encode.go

@@ -20,6 +20,7 @@ package interpreter
 
 import (
 	"bytes"
+	"fmt"
 	"math"
 	"math/big"
 
@@ -253,6 +254,40 @@ var CBOREncMode = func() cbor.EncMode {
 	return encMode
 }()
 
+func init() {
+	// Here, init is only used for sanity checks (coding errors) and does not perform any initialization.
+
+	// Check if the CBOR tag number range is not reserved for internal use by atree.
+	// Cadence must only use available (unreserved by atree) CBOR tag numbers to encode elements in atree managed containers.
+
+	// As of Aug 15, 2024:
+	// - Atree reserves CBOR tag numbers from 240 to 255 for atree internal use.
+	// - Cadence uses CBOR tag numbers from 128 to 230 to encode internal Cadence values.
+
+	// When a new tag number is needed, Atree will use higher tag number first from its reserved range.
+	// In contrast, Cadence will use lower tag numbers first from its own (different) reserved range.
+	// This allows Atree and Cadence more flexibility in case we need to revisit the
+	// allocation of adjacent unused ranges for Atree and Cadence.
+
+	minCBORTagNum := uint64(CBORTagBase)
+	maxCBORTagNum := uint64(CBORTag_Count) - 1
+
+	tagNumOK, err := atree.IsCBORTagNumberRangeAvailable(minCBORTagNum, maxCBORTagNum)
+	if err != nil {
+		panic(err)
+	}
+
+	if !tagNumOK {
+		atreeMinCBORTagNum, atreeMaxCBORTagNum := atree.ReservedCBORTagNumberRange()
+		panic(fmt.Errorf(
+			"cadence internal tag numbers [%d, %d] overlaps with atree internal tag numbers [%d, %d]",
+			minCBORTagNum,
+			maxCBORTagNum,
+			atreeMinCBORTagNum,
+			atreeMaxCBORTagNum))
+	}
+}
+
 // Encode encodes the value as a CBOR nil
 func (v NilValue) Encode(e *atree.Encoder) error {
 	// NOTE: when updating, also update NilValue.ByteSize