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feat: verify ciphertext #32

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feat: verify ciphertext #32

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b50b7d0
fibitwise operations for uint4 type
May 28, 2024
9e086f3
Merge branch 'main' of https://github.com/Inco-fhevm/fhevm-go
May 31, 2024
4b05069
feat: verify ciphertext
May 31, 2024
7be6e0b
fix: marshal function for uint4
May 31, 2024
2b97e44
Merge branch 'main' of https://github.com/Inco-fhevm/fhevm-go
May 31, 2024
1324906
fix: include verify function inside teelibMethods
May 31, 2024
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33 changes: 21 additions & 12 deletions fhevm/params.go
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Original file line number Diff line number Diff line change
Expand Up @@ -66,18 +66,19 @@ type GasCosts struct {
FheGetCiphertext map[tfhe.FheUintType]uint64

// TEE Operations
TeeAddSub map[tfhe.FheUintType]uint64
TeeMul map[tfhe.FheUintType]uint64
TeeDiv map[tfhe.FheUintType]uint64
TeeRem map[tfhe.FheUintType]uint64
TeeEncrypt map[tfhe.FheUintType]uint64
TeeDecrypt map[tfhe.FheUintType]uint64
TeeComparison map[tfhe.FheUintType]uint64
TeeShift map[tfhe.FheUintType]uint64
TeeNot map[tfhe.FheUintType]uint64
TeeNeg map[tfhe.FheUintType]uint64
TeeBitwiseOp map[tfhe.FheUintType]uint64
TeeCast uint64
TeeAddSub map[tfhe.FheUintType]uint64
TeeMul map[tfhe.FheUintType]uint64
TeeDiv map[tfhe.FheUintType]uint64
TeeRem map[tfhe.FheUintType]uint64
TeeEncrypt map[tfhe.FheUintType]uint64
TeeDecrypt map[tfhe.FheUintType]uint64
TeeComparison map[tfhe.FheUintType]uint64
TeeShift map[tfhe.FheUintType]uint64
TeeNot map[tfhe.FheUintType]uint64
TeeNeg map[tfhe.FheUintType]uint64
TeeBitwiseOp map[tfhe.FheUintType]uint64
TeeVerifyCiphertext map[tfhe.FheUintType]uint64
TeeCast uint64
}

func DefaultGasCosts() GasCosts {
Expand Down Expand Up @@ -308,6 +309,14 @@ func DefaultGasCosts() GasCosts {
tfhe.FheUint32: 150,
tfhe.FheUint64: 189,
},
TeeVerifyCiphertext: map[tfhe.FheUintType]uint64{
tfhe.FheBool: 60,
tfhe.FheUint4: 60,
tfhe.FheUint8: 60,
tfhe.FheUint16: 70,
tfhe.FheUint32: 90,
tfhe.FheUint64: 120,
},
}
}

Expand Down
4 changes: 2 additions & 2 deletions fhevm/tee_cast.go
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Original file line number Diff line number Diff line change
Expand Up @@ -22,11 +22,11 @@ func teeCastTo(ciphertext *tfhe.TfheCiphertext, castToType tfhe.FheUintType) (*t

value := big.NewInt(0).SetBytes(result.Value).Uint64()

resultBz, err := marshalTfheType(value, castToType)

resultBz, err := tee.MarshalTfheType(value, castToType)
if err != nil {
return nil, errors.New("marshalling failed")
}

teePlaintext := tee.NewTeePlaintext(resultBz, castToType, common.Address{})

resultCt, err := tee.Encrypt(teePlaintext)
Expand Down
2 changes: 1 addition & 1 deletion fhevm/tee_comparison.go
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Expand Up @@ -109,7 +109,7 @@ func teeSelectRun(environment EVMEnvironment, caller common.Address, addr common
} else {
result.Set(t)
}
resultBz, err := marshalTfheType(&result, p2.FheUintType)
resultBz, err := tee.MarshalTfheType(&result, p2.FheUintType)
if err != nil {
return nil, err
}
Expand Down
73 changes: 73 additions & 0 deletions fhevm/tee_crypto.go
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Expand Up @@ -2,6 +2,7 @@ package fhevm

import (
"bytes"
"encoding/binary"
"encoding/hex"
"errors"
"math/big"
Expand Down Expand Up @@ -88,3 +89,75 @@ func teeDecryptRun(environment EVMEnvironment, caller common.Address, addr commo
copy(ret[32-len(plaintext):], plaintext)
return ret, nil
}

func teeVerifyCiphertextRun(environment EVMEnvironment, caller common.Address, addr common.Address, input []byte, readOnly bool, runSpan trace.Span) ([]byte, error) {
logger := environment.GetLogger()
// first 32 bytes of the payload is offset, then 32 bytes are size of byte array
if len(input) <= 68 {
err := errors.New("verifyCiphertext(bytes) must contain at least 68 bytes for selector, byte offset and size")
logger.Error("fheLib precompile error", "err", err, "input", hex.EncodeToString(input))
return nil, err
}
bytesPaddingSize := 32
bytesSizeSlotSize := 32
// read only last 4 bytes of padded number for byte array size
sizeStart := bytesPaddingSize + bytesSizeSlotSize - 4
sizeEnd := sizeStart + 4
bytesSize := binary.BigEndian.Uint32(input[sizeStart:sizeEnd])
bytesStart := bytesPaddingSize + bytesSizeSlotSize
bytesEnd := bytesStart + int(bytesSize)
input = input[bytesStart:minInt(bytesEnd, len(input))]

if len(input) <= 1 {
msg := "verifyCiphertext Run() input needs to contain a ciphertext and one byte for its type"
logger.Error(msg, "len", len(input))
return nil, errors.New(msg)
}

ctBytes := input[:len(input)-1]
ctTypeByte := input[len(input)-1]
if !tfhe.IsValidFheType(ctTypeByte) {
msg := "verifyCiphertext Run() ciphertext type is invalid"
logger.Error(msg, "type", ctTypeByte)
return nil, errors.New(msg)
}
ctType := tfhe.FheUintType(ctTypeByte)
otelDescribeOperandsFheTypes(runSpan, ctType)

expectedSize, found := tee.GetTeeCiphertextSize(ctType)
if !found || expectedSize != uint(len(ctBytes)) {
msg := "verifyCiphertext Run() compact ciphertext size is invalid"
logger.Error(msg, "type", ctTypeByte, "size", len(ctBytes), "expectedSize", expectedSize)
return nil, errors.New(msg)
}

// If we are doing gas estimation, skip execution and insert a random ciphertext as a result.
if !environment.IsCommitting() && !environment.IsEthCall() {
return importRandomCiphertext(environment, ctType), nil
}

ct := new(tfhe.TfheCiphertext)
ct.Serialization = ctBytes
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@lovenoble this make sense. but we should try deserialize the ciphertext in order to ensure it is valid format like tfhe does? I guess we need to add TODO comments.

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So I check the format after decrypting it in the following lines of codes.

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So I check the format after decrypting it in the following lines of codes.

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@lovenoble Got it. But i see that the tfhe uses deserializecompact function which produces non-compact ciphertext serialization from compacted one. Guess like the original meaning of verifyCipherTextRun function gets changed in this implementation. I think its original purpose was to deserialize the compacted cipher text and returns hash of it.

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@lovenoble lovenoble Jun 3, 2024 •
edited
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I'm not sure how to implement compact serialization. Do you have any idea about it? And do we need a compact serialization for TEE case, @amaury1093 , @kenta-mori3322 ?

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@lovenoble yeah actually was trying to decode rust code to golang.

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Hi @lovenoble we have actually agreed on the fact that we won't use compacted ciphertext for TEE as it won't be so long. I think I can approve your PR.

ct.FheUintType = ctType

plaintext, err := tee.Decrypt(ct)
if err != nil {
msg := "verifyCiphertext Run() compact ciphertext is invalid"
return nil, errors.New(msg)
}

if plaintext.FheUintType != ctType {
msg := "verifyCiphertext Run() compact type mismatch"
logger.Error(msg, "type", plaintext.FheUintType, "expectedType", ctType)
return nil, errors.New(msg)
}

ctHash := ct.GetHash()
importCiphertext(environment, ct)
if environment.IsCommitting() {
logger.Info("verifyCiphertext success",
"ctHash", ctHash.Hex(),
"ctBytes64", hex.EncodeToString(ctBytes[:minInt(len(ctBytes), 64)]))
}
return ctHash.Bytes(), nil
}
18 changes: 18 additions & 0 deletions fhevm/tee_crypto_gas.go
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Original file line number Diff line number Diff line change
Expand Up @@ -34,3 +34,21 @@ func teeDecryptRequiredGas(environment EVMEnvironment, input []byte) uint64 {
}
return environment.FhevmParams().GasCosts.TeeDecrypt[ct.fheUintType()]
}

func teeVerifyCiphertextRequiredGas(environment EVMEnvironment, input []byte) uint64 {
logger := environment.GetLogger()

if len(input) <= 68 {
logger.Error("verifyCiphertext(bytes) must contain at least 68 bytes for selector, byte offset and size")
return 0
}
ctTypeByte := input[len(input)-1]
if !tfhe.IsValidFheType(ctTypeByte) {
msg := "verifyCiphertext Run() ciphertext type is invalid"
logger.Error(msg, "type", ctTypeByte)
return 0
}

ctType := tfhe.FheUintType(ctTypeByte)
return environment.FhevmParams().GasCosts.TeeVerifyCiphertext[ctType]
}
146 changes: 146 additions & 0 deletions fhevm/tee_crypto_test.go
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Expand Up @@ -6,6 +6,7 @@ import (

"github.com/ethereum/go-ethereum/common"
"github.com/zama-ai/fhevm-go/fhevm/tfhe"
"github.com/zama-ai/fhevm-go/tee"
"pgregory.net/rapid"
)

Expand Down Expand Up @@ -46,3 +47,148 @@ func TestTeeDecryptRun(t *testing.T) {
}
})
}

func TestTeeVerifyCiphertext4(t *testing.T) {
TeeVerifyCiphertext(t, tfhe.FheUint4)
}

func TestTeeVerifyCiphertext8(t *testing.T) {
TeeVerifyCiphertext(t, tfhe.FheUint8)
}

func TestTeeVerifyCiphertext16(t *testing.T) {
TeeVerifyCiphertext(t, tfhe.FheUint16)
}

func TestTeeVerifyCiphertext32(t *testing.T) {
TeeVerifyCiphertext(t, tfhe.FheUint32)
}

func TestTeeVerifyCiphertext64(t *testing.T) {
TeeVerifyCiphertext(t, tfhe.FheUint64)
}

func TestTeeVerifyCiphertext4BadType(t *testing.T) {
TeeVerifyCiphertextBadType(t, tfhe.FheUint4, tfhe.FheUint8)
TeeVerifyCiphertextBadType(t, tfhe.FheUint4, tfhe.FheUint16)
TeeVerifyCiphertextBadType(t, tfhe.FheUint4, tfhe.FheUint32)
TeeVerifyCiphertextBadType(t, tfhe.FheUint4, tfhe.FheUint64)
}

func TestTeeVerifyCiphertext8BadType(t *testing.T) {
TeeVerifyCiphertextBadType(t, tfhe.FheUint8, tfhe.FheUint4)
TeeVerifyCiphertextBadType(t, tfhe.FheUint8, tfhe.FheUint16)
TeeVerifyCiphertextBadType(t, tfhe.FheUint8, tfhe.FheUint32)
TeeVerifyCiphertextBadType(t, tfhe.FheUint8, tfhe.FheUint64)
}

func TestTeeVerifyCiphertext16BadType(t *testing.T) {
TeeVerifyCiphertextBadType(t, tfhe.FheUint16, tfhe.FheUint4)
TeeVerifyCiphertextBadType(t, tfhe.FheUint16, tfhe.FheUint8)
TeeVerifyCiphertextBadType(t, tfhe.FheUint16, tfhe.FheUint32)
TeeVerifyCiphertextBadType(t, tfhe.FheUint16, tfhe.FheUint64)
}

func TestTeeVerifyCiphertext32BadType(t *testing.T) {
TeeVerifyCiphertextBadType(t, tfhe.FheUint32, tfhe.FheUint4)
TeeVerifyCiphertextBadType(t, tfhe.FheUint32, tfhe.FheUint8)
TeeVerifyCiphertextBadType(t, tfhe.FheUint32, tfhe.FheUint16)
TeeVerifyCiphertextBadType(t, tfhe.FheUint32, tfhe.FheUint64)
}

func TestTeeVerifyCiphertext64BadType(t *testing.T) {
TeeVerifyCiphertextBadType(t, tfhe.FheUint64, tfhe.FheUint4)
TeeVerifyCiphertextBadType(t, tfhe.FheUint64, tfhe.FheUint8)
TeeVerifyCiphertextBadType(t, tfhe.FheUint64, tfhe.FheUint16)
TeeVerifyCiphertextBadType(t, tfhe.FheUint64, tfhe.FheUint32)
}

func TeeVerifyCiphertext(t *testing.T, fheUintType tfhe.FheUintType) {
var value uint64
switch fheUintType {
case tfhe.FheBool:
value = 1
case tfhe.FheUint4:
value = 2
case tfhe.FheUint8:
value = 234
case tfhe.FheUint16:
value = 4283
case tfhe.FheUint32:
value = 1333337
case tfhe.FheUint64:
value = 13333377777777777
}
depth := 1
environment := newTestEVMEnvironment()
environment.depth = depth
addr := common.Address{}
readOnly := false

resultBz, err := tee.MarshalTfheType(value, fheUintType)
if err != nil {
t.Fatalf(err.Error())
}

plaintext := tee.NewTeePlaintext(resultBz, fheUintType, addr)
ct, err := tee.Encrypt(plaintext)
if err != nil {
t.Fatalf(err.Error())
}

input := prepareInputForVerifyCiphertext(append(ct.Serialization, byte(fheUintType)))
out, err := teeVerifyCiphertextRun(environment, addr, addr, input, readOnly, nil)
if err != nil {
t.Fatalf(err.Error())
}

if common.BytesToHash(out) != ct.GetHash() {
t.Fatalf("output hash in verifyCipertext is incorrect")
}
res := getVerifiedCiphertextFromEVM(environment, ct.GetHash())
if res == nil {
t.Fatalf("verifyCiphertext must have verified given ciphertext")
}
}

func TeeVerifyCiphertextBadType(t *testing.T, actualType tfhe.FheUintType, metadataType tfhe.FheUintType) {
var value uint64
switch actualType {
case tfhe.FheUint4:
value = 2
case tfhe.FheUint8:
value = 2
case tfhe.FheUint16:
value = 4283
case tfhe.FheUint32:
value = 1333337
case tfhe.FheUint64:
value = 13333377777777777
}
depth := 1
environment := newTestEVMEnvironment()
environment.depth = depth
addr := common.Address{}
readOnly := false

resultBz, err := tee.MarshalTfheType(value, actualType)
if err != nil {
t.Fatalf(err.Error())
}

plaintext := tee.NewTeePlaintext(resultBz, actualType, addr)
ct, err := tee.Encrypt(plaintext)
if err != nil {
t.Fatalf(err.Error())
}

input := prepareInputForVerifyCiphertext(append(ct.Serialization, byte(metadataType)))
_, err = teeVerifyCiphertextRun(environment, addr, addr, input, readOnly, nil)
if err == nil {
t.Fatalf("verifyCiphertext must have failed on type mismatch")
}

if len(environment.FhevmData().verifiedCiphertexts) != 0 {
t.Fatalf("verifyCiphertext mustn't have verified given ciphertext")
}
}
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