mirror of
https://github.com/cwinfo/matterbridge.git
synced 2024-12-27 12:25:40 +00:00
97 lines
3.2 KiB
Go
97 lines
3.2 KiB
Go
// Copyright (c) 2021 Tulir Asokan
|
|
//
|
|
// This Source Code Form is subject to the terms of the Mozilla Public
|
|
// License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
|
|
|
|
package appstate
|
|
|
|
import (
|
|
"crypto/hmac"
|
|
"crypto/sha256"
|
|
"crypto/sha512"
|
|
"encoding/binary"
|
|
"fmt"
|
|
"hash"
|
|
|
|
"go.mau.fi/whatsmeow/appstate/lthash"
|
|
waProto "go.mau.fi/whatsmeow/binary/proto"
|
|
)
|
|
|
|
type Mutation struct {
|
|
Operation waProto.SyncdMutation_SyncdMutationSyncdOperation
|
|
Action *waProto.SyncActionValue
|
|
Index []string
|
|
IndexMAC []byte
|
|
ValueMAC []byte
|
|
}
|
|
|
|
type HashState struct {
|
|
Version uint64
|
|
Hash [128]byte
|
|
}
|
|
|
|
func (hs *HashState) updateHash(mutations []*waProto.SyncdMutation, getPrevSetValueMAC func(indexMAC []byte, maxIndex int) ([]byte, error)) ([]error, error) {
|
|
var added, removed [][]byte
|
|
var warnings []error
|
|
|
|
for i, mutation := range mutations {
|
|
if mutation.GetOperation() == waProto.SyncdMutation_SET {
|
|
value := mutation.GetRecord().GetValue().GetBlob()
|
|
added = append(added, value[len(value)-32:])
|
|
}
|
|
indexMAC := mutation.GetRecord().GetIndex().GetBlob()
|
|
removal, err := getPrevSetValueMAC(indexMAC, i)
|
|
if err != nil {
|
|
return warnings, fmt.Errorf("failed to get value MAC of previous SET operation: %w", err)
|
|
} else if removal != nil {
|
|
removed = append(removed, removal)
|
|
} else if mutation.GetOperation() == waProto.SyncdMutation_REMOVE {
|
|
// TODO figure out if there are certain cases that are safe to ignore and others that aren't
|
|
// At least removing contact access from WhatsApp seems to create a REMOVE op for your own JID
|
|
// that points to a non-existent index and is safe to ignore here. Other keys might not be safe to ignore.
|
|
warnings = append(warnings, fmt.Errorf("%w for %X", ErrMissingPreviousSetValueOperation, indexMAC))
|
|
//return ErrMissingPreviousSetValueOperation
|
|
}
|
|
}
|
|
|
|
lthash.WAPatchIntegrity.SubtractThenAddInPlace(hs.Hash[:], removed, added)
|
|
return warnings, nil
|
|
}
|
|
|
|
func uint64ToBytes(val uint64) []byte {
|
|
data := make([]byte, 8)
|
|
binary.BigEndian.PutUint64(data, val)
|
|
return data
|
|
}
|
|
|
|
func concatAndHMAC(alg func() hash.Hash, key []byte, data ...[]byte) []byte {
|
|
h := hmac.New(alg, key)
|
|
for _, item := range data {
|
|
h.Write(item)
|
|
}
|
|
return h.Sum(nil)
|
|
}
|
|
|
|
func (hs *HashState) generateSnapshotMAC(name WAPatchName, key []byte) []byte {
|
|
return concatAndHMAC(sha256.New, key, hs.Hash[:], uint64ToBytes(hs.Version), []byte(name))
|
|
}
|
|
|
|
func generatePatchMAC(patch *waProto.SyncdPatch, name WAPatchName, key []byte) []byte {
|
|
dataToHash := make([][]byte, len(patch.GetMutations())+3)
|
|
dataToHash[0] = patch.GetSnapshotMac()
|
|
for i, mutation := range patch.Mutations {
|
|
val := mutation.GetRecord().GetValue().GetBlob()
|
|
dataToHash[i+1] = val[len(val)-32:]
|
|
}
|
|
dataToHash[len(dataToHash)-2] = uint64ToBytes(patch.GetVersion().GetVersion())
|
|
dataToHash[len(dataToHash)-1] = []byte(name)
|
|
return concatAndHMAC(sha256.New, key, dataToHash...)
|
|
}
|
|
|
|
func generateContentMAC(operation waProto.SyncdMutation_SyncdMutationSyncdOperation, data, keyID, key []byte) []byte {
|
|
operationBytes := []byte{byte(operation) + 1}
|
|
keyDataLength := uint64ToBytes(uint64(len(keyID) + 1))
|
|
return concatAndHMAC(sha512.New, key, operationBytes, keyID, data, keyDataLength)[:32]
|
|
}
|